* GB785188 (A)

Description: GB785188 (A) ? 1957-10-23

Improvements in or relating to linear motion drive devices

Description of GB785188 (A)

A high quality text as facsimile in your desired language may be available amongst the following family members:

BE553737 (A) DE1013767 (B) FR1148679 (A) US2812455 (A) BE546381 (A) DE1030920 (B) FR70879 (E) BE553737 (A) DE1013767 (B) FR1148679 (A) US2812455 (A) BE546381 (A) DE1030920 (B) FR70879 (E) less Translate this text into Tooltip

[91][(1)__Select language] Translate this text into

The EPO does not accept any responsibility for the accuracy of data and information originating from other authorities than the EPO; in particular, the EPO does not guarantee that they are complete, up-to-date or fit for specific purposes.

PATENT SPECIFICATION : 78,S, $ 8 S Date of Application and filing Complete Specification: March 20, 1956. No 8650156 Application made in United States of America on March 25, 1955. Complete Specification Published: Oct 23, 1957. Indexatacceptance:-Classes 35, A(l C 7 C: 1 C 7 E: 4 X: 14: 15 B); 78 ( 3), C( 4:19); 80 ( 3), X 6 (At B); and 135, VHS. International Cllassification:-B 66 f F 06 h, k H 02 k. COMPLETE SPECIFICATION Improvements in or relating to Linear Motion Drive Devices We, WESTINGHOUSE ELECTRIC INTERNATIONAL COMPANY, of 40, Wall Street, New York 5, State of New York, United States of America, a Corporation organised and existing under the laws of the State of Delaware, in

said United States of America, do hereby declare the invention, for which we pray that a patent may be granted to u's, and the method by which it is to be performed, to be particularly described in and by the following statement: - The invention relates to linear motion drive devices and, more particularly, to linear motion drive devices for control purposes, is such as the control of valves or the adjustment of control rods which control the operation of atomic reactors. The problem of positioning an element movable in a linear direction arises in various types of industrial equipment and various means have been suggested to solve it The problem is further complicated in some instances where it is desired to remotely operate such elements in a system a great distance from the control point, such as in a system handling dangerous and explosive substances, which necessitates the use of remote control for the linear positioning device An example i' the operation of a coinplex chemical plant where it is, necessary to position numerous valves to control the flow of different substances from a remote location Also, when dangerous or explosive conditions develop, it is desirable to close many valves simultaneously so as to shut down the chemical plant. According to the inventionithese problems are solved by providing a linear motion drive device comprising an electric motor having a stator and a rotor, a lead screw secured against rotation and adapted to pass through a hollow bore of the rotor, drive means for axially moving said lead screw by rotation of said rotor, said drive means being mounted on one end of a plurality of rotor arms which are secured to the rotor, so as to rotate therewith, and are pivotally attached to the rotor at a point between their ends so that the ends of said arms may also move in a radial direction, the other ends of said S O rotor arms being adapted to co-operate with electromagnetic means which pivotally move said arms in one direction so as to cause engagement of said drive means with said lead screw, and biasing means for biasing said 35 rotor arms in the opposite direction, so as to effect disengagement of said driving means from said lead screw upon de-energisation of said electromagnetic means. In a preferred embodiment of the inven 60 tion, the linear motion drive device incorporates a lead screw driven by a synchronous reluctance motor and expanding nut The rotor of the motor is provided with individual movable rotor arms on which the ex 65 panding nut is mounted so that it can be disengaged from the lead screws, and the latter driven in a linear direction by other means. In addition, the linear motion device is so designed that it fails safe in case the power 70 supply to the drive motor fails When the power fails, the linear motion device will move the control element to

one extreme control position automatically, without further actions on the part of the operator 75 The invention will become more readily apparent from the following detailed description of several exemplary embodiments thereof, illustrated in the accompanying drawings in which: So Fig 1 is a longitudinal section of one embodiment of the invention; Fig 2 is a partial transverse section taken along the line II-II of Fig 1 and drawn to an enlarged scale; 85 Fig 3 is a partial transverse section taken along line III-III of Fig 1 also drawn to an enlarged scale; Fig 4 is a partial view of Fig 1 showing the mounting of the rotor tube in the motor 90 frame drawn to an enlarged scale; Fig 5 is a partial longitudinal veiw partly in section of a modification of the invention showing the use of balls to drive the lead screw of the embodiment shown in Fig 1; Fig 6 is an end view of the modification shown in Fig 5 with the lead screw in section; Fig 7 is a view similar to Fig 5 of another modification of the invention showing the use of rotating pins to drive the lead screw of the embodiment shown in Fig 1; Fig 8 is a longitudinal section of a second embodiment of the invention, and Fig 9 is a longitudinal section of a third embodiment of the invention. The embodiment of our invention illustrated in Figs 1 to 4 is comprised-generally of an extended-tubular-motor frame, a statorwinding and a reluctance type of rotor rotatably mounted in-the motor frame The rotor has an enlarged portion at one end which hats a hollow bore through which the lead sctew may pass and a portion at the other end consisting of a plurality of pivoted arms. Sectors of an expanding nut are used for driving the lead screw in an axial direction and are attached to one end of the pivoted rotor arms The -pivoted rotor arms are spring biased so that the ends of the pivoted rotor arms adjacent the expanding nut will move outwardly and hold the sectors of the expanding nut free of the lead screw when the statorwinding is de-energized When the stator winding is energized, theother ends of the pivoted rotor arms, which form part 3 I of the reluctance rotor, will move outwardly about their pivot points, and the sectors of -the expanding nut will move inwardly and engage the lead screw and drive it in an axial direction as the rotor rotates. The stator shown in Fig 1 may have a 3-phase, 4-pole winding, and when supplied with 3-phase alternating-current power, will cause the rotor to rotate in synchronism with the power supply If the 3-phase alternating-current power is supplied from any well knowni source where the frequency may be varied, the speed of the rotor, and thus the speed of the axial movement of the lead screw, can be accurately controlled by controlling the frequency If it is desired to lock the lead screw in any position, all that is necessary is to reduce the frequency of the 3-phase power source to zero and maintain the

excitation of the stator so that there is no rotating magnetic field If it is desired to disconnect the expanding nut from the lead screw, all that is necessary is to de-energize the stator windings, in which case the spring biasing of the pivoted rotor arms will cause the sections of the expanding nut to move out of engagement with the lead screw. The exact position of the lead screw, and thus the position of the controlled element, will always be known because each complete cycle of the threephase power supply will correspond to a fixed fraction of one revolution of the expanding nut This relationship between the power supply and the lead screw can easily be supplied to a suitable indicating device which will give a direct reading of 70 the position of the lead screw. The embodiment of the invention illustrated in Fig 1 is designed so that it may be operated with its motor rotor, expanding nut and lead screw immersed in any fluid in 75 which the control element may be operating. The ability of the linear motion device to operate with its motor unit thus immersed is important because it eliminates the need for mechanical seals to isolate the motor unit 30 from such fluid in the system In cases where dangerou's or explosive fluids are handled and leakage thus becomes serious, the linear motion device may be completely sealed, thus eliminating leakage as -The tubular motor frame 10 and lower housing 12 -of the linear motion device are joined by means of a threaded connection -13 The motor frame 10 has a heavy section at its lower end on which the threaded 90 connection 13 is formed This heavy section gradually reduces to a relatively thinned walled section 58 of uniform cross section. The stator assembly 22 to be described later is placed on the outer surface of the section 95 58 of the motor frame Thus the section 58 serves both as a support member for the stator and as a barrier to isolate the stator windings from the fluid in which the linear motion unit may be operating The motor 100 frame 10 enlarges into a heavy walled section at the upper end of the stator assembly 22 and then again tapers into a substantially uniform tubular shape for the remainder of its length The motor frame 10 and housing 10 W 12 have a general tubular shape and are preferably of a corrosion-resisting material, such as stainless steel. If it is desired to operate the linear motion device in a sealed system with substantially 110 -zero leakage allowance, the threaded connection 13 may be sealed by means of a seal weld 19 Seal weld 19 is composed of two curved converging flanges 14 and 16 on motor frame 10 and lower housing 12, re 115 spectively, which are welded together at their free ends in the area 18 The lower housing 12 is connected

directly to the valve body or other housing _ontaininr the element to be operated by any suitable means (not shown) 120 The stator assembly 22 is positioned on the outer surface of the motor frame 10. Prior to the slipping of the stator assembly 22 onto the motor frame, an annular spacer ring 20, which encloses the end turns at one 123 end of the stator assembly and serves to accurately locate the stator assembly 22 on the motor frame, is positioned on the top surface of lower housing 12 The stator assembly is comprised of stacked stator lamin 130 a 785,188 frame 10 to separate the motor frame 10 and the upper housing 46 and further strengthen the motor frame 10 The annular opening between the motor frame 10 and the upper housing 46 at the top of the device is closed 70 by means of a threaded end cap 50 The central opening at the upper end of the motor frame 10 is closed by means of a threaded plug 52 which may be sealed by a small weld 54 if it is desired to operate the 75 linear movement in this device in a system having a zero leakage allowance The threaded plug 52 has a rod-like projection 56 which extends into the opening in the motor frame 10 and serves to guide the 80 spring 120 which is used to move the lead screw when the stator windings are de-energized, as will be described later. Thus, a completely hermetically sealed motor frame for the linear motion device has 85 been provided which can be attached directly to other equipment Thus the linear motion device can be operated with its rotor and lead screw immersed in the fluid in which the equipment is operating without danger of 90 the fluid escaping The stator windings of the device are isolated from the fluid in which the rotor is immersed by a section 58 of the motor frame 10 described above The section 58 of the motor frame 10 is designed to 95 withstand extremely high pressures on the order of 2,000 pounds per square inch ( 140 Kg/cm 2) without requiring any additional supporting members Yet due to the material used, it does not impair the electrical effi 100 ciency of the motor unit It is preferred to, use a material having between 40 to 60 per cent of the magnetic permeability of silicon steel so that the electrical efficiency of the motor is maintained and the member can be 105 made heavy enough to withstand extreme pressures without requiring supporting members It was found that certain stainless steels have the proper magnetic properties and, in addition, great strength Thus the 110 motor frame 10 serves both to isolate the stator windings and to support the remainder of the motor parts. When it is necessary to service the stator and its windings, such service can be ac 115 complished without breaking the hermetic seals of the motor frame since the stator assembly is slipped on over the outer surface of the motor frame This feature is important when the fluid in the system is of a 120 highly dangerous or explosive nature

ats it prevents its escape from the system Of course, if it is necessary to remove the device from the system, the seal weld 19 can be easily broken and the motor frame 10 un 125 screwed from the lower housing 12 thus removing the frame 10 including the lead screw and rotor from the remainder of the system. The rotor assembly is assembled outside of the tubular motor frame and inserted into 130 ations 24, of a magnetic material such as iron, which have inwardly opening slots (not shown) in which suitable stator windings are inserted The Istator windings have end turns S 26 and 28 extending at each end of the stator assembly 22, respectively The stacked stator laminations 24 may be held together as a unit by any suitable means, such as welding along their outer surfaces A thin walled -10 metal tube 25 preferably of a corrosion resisting material, such as stainless steel, is slipped over the outer surface of the stator laminations so as to completely enclose the stator assembly A shoulder 30 at the lower end of the stator assembly 22 rests against the top edge of the annular spacer ring 20 and serves, in co-operation with the annular spacer ring 20, to accurately locate the stator assembly in an axial position along the outer surface of the motor frame section 10. A second tube 32 preferably of a corrosionresisting material, such as stainless steel is positioned around the outer surface of the first thin walled tube 25 which enclosed stator winding, and is radially spaced from the first thin wall tube 25, by two inwardly projecting ridges 29 and 31 formed on the inner surface of tube 32 adjacent its upper and lower ends, respectively, so as to enclose a small-annular area 33 therebetween The annular area 33 is sealed at its lower end by means of a sealing ring 34 of a resilient material, such as neoprene, which fits in a co-operating groove 35 formed on the inner surface of tube 32 The upper end of annular area 33 is sealed by a sealing ring 36 of similar material, which fits between a flange 37 on tube 32 and the lower end of a second spacing ring 38. A cooling medium may be circulated in the annular area 33 to cool the stator assembly by any suitable means (not shown) in those cases where the linear motion device is used in a system handling high temperature fluids. The second annular spacing ring 38 is used to enclose the upper end turns 26 of the stator assembly and is located by means of a shoulder 40 formed in its lower end which rests on the upper surface of stator assembly 22 The complete stator assembly is locked in position by means of a threaded central housing 44 which threads onto a heavy section of the motor frame section 10 An outwardly projecting flange 43 on the central housing 44 rests on the top surface of-the annular ring 38 and serves to force the complete stator assembly 22 into

position against the top surface of the annular spacing ring 20. An upper housing 46 is bolted to the central housing 44 by means of bolts 47 which pass through flanges 43 and 45 on central housing 44 and the upper housing 46 respectively Stiffening rings 48 are positioned at intervals along the outer surface of the motor 785,188 the tubular motor frame 10 prior to the join form outwardly projecting portions 85 at each ing of the tubular motor frame 10 and lower side of the upper portion The shape of the housing 12 The rotor has a rotor tube 60, upper portion of the rotor arms 72 described preferably of a magnetic material, such-mag above can readily be seen in Fig 3. netic stainless steel, and pivoted rotor arms One corner 75 of the inner race of ball 70 72 of similar material Therotortube 60 has bearing 64 serves as a pivot point for the an enlarged upper portion 59 which forms pivoted rotor arms 72 Each rotor arm has part of the salient pole structure required of formed on its outer surface a channel shaped a reluctance type of motor The upper por radial groove 74 of which one corner 77 acts tion 59 may have longitudinal grooves (not as a pivot about the pivot point 75 on inner 75 shown) formed on its outer surface in order race of the ball bearing 64 The segments of to form the salient poles referred to above the expanding nut are attached to the lower The remainder of the salient poles are ends 78 of the pivoted rotor arms 72, respecformed by the rotor arms 72 which will be tively In the embodiment of the invention -15 described later The upper end of the rotor shown in Fig 1 the segments of the expand 8 G tube 60 (Fig 4) is rotatably mounted by ing nut are comprised of four rollers 80 and means of a ball bearing 62, the inner race of 801, two of which 80 have two outwardly which rests on a shoulder 63 formed on the projecting spaced radial flanges 92 which are rotor tube 60, and the outer race of which adapted to roll in engagement with threads -20 rests on a shoulder 70 formed on the motor 1 G 2 on the lead screw 100, and two of which 85 frame 10 The ball bearing 62 is not rigidly 80 ' have plain surfaces (Fig 2) and act as secured in position but is allowed to move guide rollers The radial flanges 92 are Tngicudinally in the motor frame 10 to allow formed with converging sides so that they for expansion and contraction of the rotor accurately fit the corresponding thread 102 -25 tube 60 A V-shaped flat radial spring 65 is on the lead screw 100 The rollers 80 and 9 ( 1 inserted between the outer race of ball bear 80 ' in addition form the outer race of a ball ing 62 and the shoulder 70 on the motor bearing wh Qse inner race is composed of two frame 10 in order to allow a restricted axial annular rings 84 Suitable bearing balls -82 movement of the rotor tube 60 The lower are placed between the outer race 80 and the -30 end of the rotor tube 60 is rotatably moun inner race 84 and serve to rotatably mount 95 ted by means of a second ball bearing 64 the rollers 80 The

complete roller assembly The outer race of the ball bearing 64 is is secured to the end of the pivoted rotor locked between a shoulder 67 on the lower arms by means of a nut 88 and a lock washer housing 12 and a shoulder 69 on motor frame 90 Spacer washers 86 are positioned at both :35 10 when the motor frame 10 and lower hous ends of the completed assembly so that the 10 o ing 12 are assembled as previously described projecting flanges 92 on the rollers 80 can be The inner race of the ball bearing 64 is se accurately aligned with the threads 102 on cured to a plurality of spaced radially out the lead screw While we have shown two wardly projecting webs 71 on the lower end of the rollers 801 with slain outer surfaces. of the rotor tube 60 by means of arcuate-4 -it is apparent that all four of the rollers in 105 shaped clips 66 and cap screws 68 which Fig 2 could have projecting flanges and act thread into the lower end of the rotor tube as drive rollers. The clips 66 serve to lock the inner race The upper or confined ends of the pivoted of the ball bearing 64 against an outwardly rotor arms 72 are retained in the rotor tube projecting radial flange 73 on the lower end 60 by means of a projecting tongue 81 on 110 of the webs 71 which project from the rotor each of the pivoted rotor arms 72 Each of tube 60 the tongues 81 fits in an annular recess 79 Pivoted about the inner race of ball bear formed in the enlarged section 59 of the rotor ing 64 are-the rotor arms 72 (Figs I, 2 and tube 60 The pivoted rotor arms 72 are 3) which serve a dual purpose First, the spring biased adjacent their lower ends so 115 lower end of the rotor arms are adapted to that they will move the expanding nut seg-engage and disengage the segments of the ments out of engagement with the lead screw. expanding nut from the lead screw; and As shown in Fig 2,thte expanding nut segsecond, the opposite ends of the rotor arms ments are engaged with the lead screw 100. -:serve to form parts of the salient pole struc The spring biasing arrangement is comprised 120 ture of the rotor As can be seen in Fig 3, of generally U-shaped clips 104 which have ihe upper portion of the rotor arms 72 are their bight portions attached to the pivoted formed so that they contribute to the sa Jient rotor arms 72 by means of cap screws 106. polestructure of the enlarged portion 59 of Compression springs 108 are placed between 60the rotor tube 60 previously described and adjacent ends 103 of clips 104, respectively, 125 -are aligned with the -salient pole structure and are prevented from falling out of posiof the rotor tube 60 Each rotor arm 72 has tion between the two clips 104 by means of an upper portion which is formed in section pmi-like projections 105 on the ends 103 of in the shape of a sector

of a circle which has the clips 104 The end projections 105 a ce 6 ntral groove 83 on the outside thereof to loosely fit the inner diameter of the com 130 -785,188 pression springs 108 and serve to hold them direction may be attached to the lower end in place, yet allow them freedom of move 110 of the lead screw 100 by any suitable ment. Thus, a novel means has been provided for both mounting the rotor of the linear motion device and pivoting the rotor arms. The lower, ball bearing 64 of the device serves two purposes, first to rotatably mount the rotor tube 60 and second to provide a pivot point for the rotor arms This design results in fewer parts and a simplified construction, and thus requires less maintenance, which is important in a device designed to operate in a system handling dangerous or explosive fluids and where any maintenance involves great expense. A's shown in Fig 1, when the stator is energized and the upper ends of the pivoted rotor arms 72 are pulled outward towards the stator, the lower ends of the pivoted rotor arms move inward This results from the magnetic field set up by the stator attracting the magnetic material from which the pivoted rotor arms are formed Of course, as the upper ends of the rotor arms move outward, the lower end's move inwardly and the rollers engage the lead screw 100 The direction and rate of travel of the lead screw 100 can then be easily controlled by controlling the frequency and sequence of the power supply. If it is desired to retain the lead screw in any fixed position all that is necessary is to reduce the power supply frequency to zero and while maintaining the stator energized The upper ends of the pivoted arm's 72 will thus remain in the outward position and the rollers will remain engaged with the lead screw When it is desired to move the lead screw to its extreme lower position all that is necessary is to de-energize the stator winding When the stator is de-energized, the upper ends of the pivoted rotor arms will no longer be attracted outwardly by the stator and thus the spring biasing arrangement shown in Fig 2 will disengage the rollers fr 6 m the lead screw The lead screw will immediately be driven to its lowest position by the force of compressed spring 120, to-be described later, and gravity The lead screw will likewise be driven to its lowest position when the power supply fails since this will result in the de-energizing of the stator It is assumed that the lowest position of the lead screw will be the closed position or safe position for the control element which the lead screw is Dositioning The linear motion device could easily be altered so that the lead screw is moved in the opposite or upward direction when the stator windings were de-energized instead of downward It is preferred to have it move downward in order to take advantage of the force of gravity to help drive the lead screw.

The valve stem, control element, or other device which it is desired to move in an axial means (not shown) The enlarged upper end 116 of the lead screw 100 shown in Fig. l has inwardly projecting longitudinal 70 grooves 115-which slide axially in co-operation with outwardly projecting splines 118 on motor frame section 10, and serve to prevent rotation of the lead screw Thus, when the rotor is rotated, the expanding nut will drive 75 the lead screw in an axial direction insteadl of rotating the lead screw A coiled compression spring 120 is contained in a hollow portion formed in the upper end of the lead screw 100 and seats against a shoulder 114 80 formed on the inner surface of the hollow portion of lead screw 100 The coiled spring reacts against the upper end of the motor frame 10 to drive the lead screw in a down-ward direction when the stator is de-ener 85 gized and the expanding nut is moved out of engagement with the lead screw The enlarged end section 116 of the lead screw 100 also serves to prevent the lead screw from passing through the rotor tube 60 when the 90 stator is de-energized and the lead screw is driven to it' lowest position. Two modifications of the roller type of expanding nut 80 for driving the lead screw shown in Figs 1 and 2 are shown in Figs 95 5, 6 and 7 In Fig 5 a-ball 132 is rotatably mounted on supporting race 130 by means of two balls 131 which are held in position by means of retaining cap 133 Retaining cap 133 is secured to the lower end of a modified 100 rotor arm 72 ' by means of cap screws 134 which pass through the rotor arm 721 and thread into retaining cap 133 Retaining cap 133 also serves to hold supporting race 130 iin place as shown in Fig 5 Two clips 135 105 (Fig 6) hold the ball 132 in place when the rotor arm 72 ' is moved outward to disengage -the balls 132 from the lead screw as described above for Fig 1 Clips 135 are attached to retaining cap 133 by means of cap 110 screws 136 In order to obtain a reasonable size for the balls 132, the lead screw 100 of -Fig 1 is replaced by a new lead screw 100 which has a higher pitch than the lead screw of Fig 1 115 In Fig 7 the roller nut 80 of Fig 1 is replaced by an -expanding nut composed of rotatably mounted pins 140 The pins 140 have one end formed in the shape of a truncated cone 141 whichi engages the lead screw 120 -100 and drives it in an axial direction The pins 140 are rotatably mounted in one end of a modified rotor arm 72 "' by means of a double row ball bearing 142 A spring clip143, which fits in a radial groove 145 formed 125 on the other end of the pin 140, retains the pin 140 in place; Clip 146 is attached to rotor arm 72 by two small cap screws 144 and serves to retain the double row ball bearing 142 in place While only two modi 130 785,188 is 785,188 fied rotor arms are shown in Figs 5, 6 and. 7, the remaining rotor arms 72 shown in Fig.

1 may have plain faced rollers 80 ' mounted on their lower ends 78 as described above. : S The plain faced rollers 80 ' would act as guide rollers for lead screw 100 in Figs 5, 6 and 7 in the same manner as described for Fig 1. Both of the modifications of the roller nut shown in Figs 5 to 7 have only one element on each rotor arm to engage the lead screw which greatly simplifies the alignment of the element with the lead screw over the roller shown in Fig 1 The roller 80 in Fig 1 having two outwardly projecting ridges 92 may be difficult to align with the lead screw so that each projecting ridge 92 supports its portion of the load. A second embodiment of the invention is 2 o illustrated in Fig 8 and is generally similar to the embodiment illustrated in Fig 1 The added novel feature of this embodiment is the -addition of a circular electromagnetic coil 160 for creating the magnetic field used in actuating the rotor arms 172, instead of utilizing the magnetic field of the stator 22 as in Fig 1. In order to provide for the space necessary for the magnetic coil 160, a modified -30 tubular motor frame 152 is Drovided with a longer section 154 of uniform cross-section than the motor frame 10 of Fig 1 A longer annular spacing ring 150 must also be provided instead of the spacing ring 20 of Fig: 1 for enclosing the lower end turns 28 of the stator winding as it, in addition, encloses themagnetic coil 160 A new rotor-tube 156 is rotatably mounted by means-of ball bearings 62 and 64 in the same manner as described for mounting rotor tube 60 of Fig 1 Rotor tube 156 differs from rotor tube 60 in that it has an enlarged section 158 of increasedlength over the enlarged section 59 of rotor tube 60 which is made possible by removal of the rotor arms 172 from the area adjacent -the stator windings 272 The enlarged section of the rotor 156 is made at least as long as the stator laminations 24 whose length depends on the power desired of the motor. The uniform section 158 of rotor tube 156 has formed on its outer surface longitudinal grooves (not shown) which form the salient pole structure of this embodiment, as is well known in the motor field The circular electro-magnetic coil 160 is enclosed in a suitable housing 162 preferably of an insulating material, such as a synthetic resin, and is installed on the outer surface of motor frame 152 adjacent the upper end of the rotor arms 172 Rings 163, preferably of a magnetic material such as soft iron, are placed at each end of the coil 160 to increase its magnetic field and thus increase the outward radial force on the rotor arms 172 The remaining details of construction and the method of assembling the various parts are the same as described and

shown in Fig 1 and accordingly, such similar parts are indicated by the same reference numerals, and their descrip 70 tion will not be repeated. The embodiment of the invention described above has several advantages over the embodiment shown in Fig 1 First, the motor unit has more torque and thus the 75 axial movement of the lead screw will be more forceful and positive The added motor torque is due to the fact that the rotor tube 156 has an increased amount of magnetic material in the magnetic field of the stator 80 22 This arrangement is not possible in the embodiment of Fig 1 because the rotor arms 172 must extend into the magnetic field of the stator in order to be actuated by the stator field thus preventing the use of a rotor 85 tube similar to 156 of Fig 8 Another advantage is the ability to engage or disengage the expanding nut from the lead screw 100 without regard to the energizing or de-energizing of the stator winding This is im 90 portant because it allows the lead screw to be locked in any axial position without having the stator windings energized, which in turn, considerably reduces the heat generated in the stator laminations 24 This embodi 95 ment will also fail safe in case of failure of the power supply since the magnetic coil 160 acts in the same manner as the stator of Fig. 1 in actuating the rotor arms. A third embodiment of the invention is loo -illustratedi in Fig 9 and is generally similar to the embodiment illustrated in Fig 1 This embodiment, in addition to including all of the novel features of the embodiment illuistrated in Fig 1, includes a novel rotor con 105 struction where all of the salient pole structure of the rotor is formed by the pivotedl rotor arms This arrangement, while somewhat decreasing the torque delivered by the motor, greatly increases the radial force tend 110 ing to move the upper ends of the pivoted rotor arms radially outward and the lower ends inwardly This increased radial force is due to the increased amount of magnetic -material,= from which the rotor arms are i 15 fabricated, being acted upon by the magnetic field of the stator windings The increased length of the rotor arms also increases the above radial force due to the increased lever arms This embodiment is i 20 particularly desirable where the -linear motion device will be ambiect to considerable vibration and sudden shocks, as the increased radial force will maintain the expanding nut in engagement with the lead 125 screw. In this embodiment, the stator is assembled as a separate unit and inserted into the outer casing 202 of the linear motion device instead of being slipped on the outer sur 130 -6 the rotor arms 240 adjacent the stator windings form the salient poles of the rotor in this embodiment of the invention, and have the same cross-sectional shape

as shown in Fig. 3 for the rotor arms 72 of Fig 1 The rotor 70 arms 240 are prevented from over-traveling in a radial direction when the stator windings are energized by a small tongue 242 on their upper ends, each of which fits in an oblong-shaped radial slot 244 Slot 244 is 75 formed in a radial flange 246 which projects outwardly from the upper end of the rotor tube 228 A spring biasing arrangement 250, identical to that shown in Fig 2, moves the upper end of the rotor arms 248 inwardly 80 against the rotor tube 228 when the stator windings are de-energized so as to disengage the roller drive 252 The lead screw 100, which is identical to the lead screw shown in Fig 1, is driven by an expanding roller nut 85 assembly 252 Roller nut assembly is of the same construction as the roller nut 80 shown in Fig 1. In this embodiment, the pivoted rotor arms extend completely through the stator field 90 This greatly increases the radial force on the rotor arms, and thus increases the inward radial force tending to keep the expanding nut 252 engaged with the lead screw 100. This is very important where the linear 95 motion device will be subjected to shock and vibration which would tend to disengage the nut from the lead screw. As can be seen from the above description, three embodiments of the linear motion 100 device have been provided whcih fail safe. By failing safe we mean that when the power supply for the stator assembly 22 and/or the electromagnetic coil 160 is interrupted or fails, the expanding nut is moved out of en 105 gagement with the lead screw 100 and the coiled compression spring -120 will immediately drive the lead screw 100 to its extreme downward position This extreme down ward position, of course, can be designed as 110 the safe position for the device which the linear motion device is actuating In addition, by utilizing a low frequency 3-phase power supply, an accurate record of the position of the lead screw can be maintained by 115 maintaining a record of the power supply. If the supply frequency is made variable, the speed of movement as well -as the direction of the lead screw can be accurately controlled In addition the linear motion device 120 has a minimum of parts thus making it easy to manufacture and relatively free of maintenance.

* Sitemap * Accessibility * Legal notice * Terms of use * Last updated: 08.04.2015 * Worldwide Database

* 5.8.23.4; 93p

* GB785189 (A)

Description: GB785189 (A) ? 1957-10-23

Improvements in or relating to method and apparatus for electrodeposition

Description of GB785189 (A)

A high quality text as facsimile in your desired language may be available amongst the following family members:

FR1149265 (A) US2784151 (A) FR1149265 (A) US2784151 (A) less Translate this text into Tooltip

[81][(1)__Select language] Translate this text into

The EPO does not accept any responsibility for the accuracy of data and information originating from other authorities than the EPO; in particular, the EPO does not guarantee that they are complete, up-to-date or fit for specific purposes.

PATENT SPEC FI A I 189 PATENT SPECIFICATION 785,189 Date of Application and filing Complete Specification March 20,1956. No 8743/56. Application made in United States of America an March 25,1955. Complete Specification Published Oct 23, 1957. Index at Acceptance:-Class 41, A(QC 12: 5), B( 1 S: 15 X). International Classification:-C 23 b. COMPLETE SPECIFICATION Improvements in or relating to method and apparatus for electrodeposition We, TIA Rco CORPORATION, a corporation organized under the laws of the State of New Jersey, one of the United States of America, of 107 Vesey Street, City of Newark, State of New Jersey, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it

is to be performed, to be particularly described in and by the following statement: - The invention relates to improvements in electrodeposition, and more particularly to methods for distributing current and the distribution of metal deposited in plating of articles of irregular shape, or articles having multi-planar areas and apparatus for carrying out the method. Plating baths which have poor throwing power, or baths requiring the use of relatively high current densities, present coverage problems when the object to be plated is of irregular shape Those portions of the article located closer to the anode receive a heavier deposit than the portions which are farther away Objects which are quite regular in shape, but which have an edge or corner where two or more surfaces meet also present difficulties when it is desired to plate the edge or corner "Treeing" or excessive rounding occurs at the edge of the multi-planar area. Various means have been used to overcome the aforementioned problems These previously known means possess individuallimitations of one kind or another A common device for obtaining more uniform current distribution and metal deposit coverage is the shaped anode Shaped anodes, however, can only be used where the object to be plated is not unduly complicated in shape Otherwise, the cost of making a conforming anode becomes prohibitive. Moreover, a shaped anode is only useful for plating an article of given contour, and, therefore, affords little of the flexibility desired in a plant handling a wide variety of lPdce 3 s e 4;C 45 6 d articles of many different shapes. "Thieves " or "robbers" have been widely used to obtain improved current distribution or coverage These auxiliary conductors are placed near points of abnormally high 50 current density to divert current away from such points Such conductors must be carefully spaced from the selected points or areas of the object Such spacing is critical, timeand-effort-consuming, and economically 55 burdensome Moreover, there are some objects having such irregular shapes that the use of a "thief" is impractical, if not impossible. Shields or masks, which are made of non 60 conductive material, have been used to divert current away from areas where it concentrates unduly This approach has only limited application, because many irregularly shaped articles require continuous 65 coverage, rather than selective coverage and non-coverage. It has also been proposed to provide a supporting cathode fixture formed with a serrated edge to engage the edge of a metal 7 Q sheet to be plated This fixture supports a flat sheet in the bath, the cathode current being supplied to the supporting fixture The edge of the sheet

engaged by the serrated edge of the supporting fixture was found to 75 be uniformly plated, notwithstanding direct contact with the serrated edge This prior art device has limited application, there being many objects which have contours which We have found that by covering the multiplanar area of an object, whether projections and recesses of an irregularly shaped object, or the edge or corner of a regularly shaped object, with a flexible, porous, electrically 85 conductive sheet or fabric, over-all metal deposition is obtained, while preventing "treeing" or undue rounding of the object's projections or edges While any deformable, foraminous, electrically-conductive sheetmay 90 be used, we prefer to use ordinary, commercial, woven wire-mesh fabric or screening, although it will be understood, of course, that the degree of porosity or size of mesh of the wire fabric will depend upon the size of the particular object to be plated, the current density used and the time of plating Being deformable, it can be wrapped around the object, assumes and retains the shape given to it upon bending, and thereby permits the object itself to serve as its support Instead of expensive forming operations to make a shaped anode for a given article, or requiring great care in critically spacing a "thief" from a projection, the current distributing means of the present invention is applicable to an extremely wide variety of objects having different multi-planar areas in a very simple, inexpensive and universal manner. In accordance with the present invention, objects of such widely different shape and contour as twist drills, countersink bits, reamers, taps, saws, knives, cutters, gears, variously shaped punches and dies; in fact, practically any object having a multi-planar area, may be plated in baths possessing poor throwing power, or baths requiring high current densities, with the accomplishment of sharp defined plated projections or edges and deposition within the recesses In the case of cutting tools, the metal deposited conforms to the cutting edge so well that subsequent sharpening is often not needed. It will thus be apparent that the present invention possesses great advantages in industrial chromium plating Tools, punches and dies of high carbon steels or of tungsten carbide have their life increased several fold. The chromium plated objects have imparted to them the advantageous properties of chromium, such as a low coefficient of friction, resistance against spalling, extreme hardness and resistance to corrosion. To these ends, the present invention consists in providing a method of electrodepositing metal from a bath having poor throwing power onto an object having a multi-planar area, comprising covering the multi-planar area with a porous, electrically-conductive fabric, making the fabric-covered object the cathode in the bath, and passing

current between the object and an anode. Still further, the present invention proposes apparatus for plating metal from a bath having poor throwing power onto an object having a multi-planar area, comprising a bath, the bath having therein an anode, the object, with the object constituting the cathode, and a porous, electrically-conductive fabric, the fabric being deformed about the object so that it is supported thereby with the fabric overlying the multi-planar area, whereby upon passage of current between the anode and and the cathode-object the fabric acts to distribute the current. In order that the invention may be more clearly understood and readily carried into effect, the same will now be described more fully with reference to the accompanying drawings, in which: 70 Fig 1 is a plan view of a wire-mesh fabric, which preferably is used to carry out the present invention; Fig 2 is a plan view of a twist drill being prepared for plating in accordance with the 75 present invention; Fig 3 is a similar view showing the twist drill covered with the wire-mesh fabric and ready for insertion in a plating bath; Fig 4 is an enlarged transverse vertical 80 sectional view taken approximately in the plane of line 4-4 of Fig 4; Fig 5 is a cross-sectional view of a plating bath showing the prepared twist drill being plated; 85 Fig 6 is a side elevational view of a saw having its cutting edges covered with the current distributing means of the present invention preparatory to insertion in a plating bath; 90 Fig 7 is an enlarged, transverse vertical sectional view taken approximately in the plane of line 7-7 of Fig 6; and Fig 8 is a perspective view of a spur gear having its teeth covered with the current 95 distributing means of the present invention. The method of the present invention, and the novel results obtainable from the practice thereof, may generally be described in connection with the chromium plating of 100 high-speed twist drills ' A one-quarter inch high-speed twist drill A is first degreased in a manner well-known in the art, and then covered 'with a deformable, porous, elertrically-conductive sheet or fabric B Pre 105 ferably, the sheet or fabric B comprises woven wire-mesh fabric of the ordinary commercial type, such as a one-sixteenth inch mesh screening which which the galvanized coating has been removed The wire-mesh 110 fabric may be made of any other suitable metal, such as, copper or brass Also, instead of a wire-mesh fabric, the deformable, porous, electrically-conductive sheet may be made by suitably perforating a thin 115 metal sheet. As shown in Figs 2 to 4, to cover the drill A, a strip of wire-mesh fabric B is used having a width equal to, or very slightly R-cater than, the circumference of the drill 120 The length of the strip is

made approximately three-quarters of an inch longer than the drill body 10 so that the strip extends beyond the drill's lips or cutting edges 12 and for a short distance up on the shank 14 125 The stri D B is tightly wrapped or bent around the body of the drill, thereby forming a longitudinal seam 16 where the longitudinal edges of the strip abut each other. The strip is pinched at the lower end 18 130 so that the strands do not touch the cutting edges 12, although care need not be exercised to avoid the contact In any event, the mesh fabric tightly envelops the body of the drill 785,189 Thus it is apparent that the readily deformable wire-mesh fabric acts to distribute the current in a fashion which permits over-all 70 metal coverage of an object having a multiplanar area The object itself may serve as a support for the current distributing means. Recesses, as well as projections, can be deposited with metal from baths having poor 75 throwing power, while avoiding "treeing" or undue rounding on the sharp edges or projections The part of the wire-mesh fabric overlying a projection and recess may be in contact with the projection or spaced there 80 from, and the spacing is not critical insofar as avoidance of "treeing" is concerned. Heavy deposits may be obtained without sacrificing conformity to the contour of the underlying object The sharpness of a cutting 85 edge may be retained with all the advantages of having the edge covered with chromium; namely, low coefficient of friction, resistance to spalling, resistance to corrosion, and extreme hardness 90 Figs 6 and 7 illustrate the invention as applied to a cross-cut saw C For this application, the wire-mesh fabric B is shaped around the cutting teeth 36 and is of a width to extend for a short distance beyond and 95 down on the body of the saw The mesh fabric strip is cut to a length to extend around the lateral non-cutting edges 38 and so that, without any additional support, the saw serves as a support for the current 100 distributing means Care is exercised not to push the teeth through the wire fabric For this application, a hooked strap 42 may be passed through one of the apertures 44, which ordinarily serves as a means for secur 105 ing a handle to the saw When hung from the cathode bar of the chromium plating tank, and with the wire-mesh covered side facing an anode in an industrial chromium plating bath, which may be of the type 110 described above, the teeth are plated so that they maintain their sharpness and do not require sharpening The chromium deposit follows the multi-planar area presented by the saw teeth without "treeing" or undue il S rounding. Fig 8 illustrates the invention as applied to a spur gear D, for which application the wire-mesh fabric B is conformed around the extreme outer periphery to cover the teeth 120 46 and the intermediate

recesses 48 The strip B is cut to width so that it extends down on the body of the gear, below the-base of the recesses The seam formed by the abutting edge on the periphery is located between 125 a pair of teeth In plating a gear, the strap or means for connecting the gear to the cathode bar may be passed through its bore 50, and suspended in a bath surrounded by a plurality of anodes equidistantly spaced 130 from its periphery or teeth. While the chromium plating of several specific obiects having multi-planar areas has been described, it will, of course, be so that the wire-mesh fabric covers and is against the land portion 20 of the drill No effort is made to force the wire-fabric into the drill's flutes 22 The drill is then masked at the top or shank 14, as by lacquering or by wrapping a strip of insulating material 24 around it with a hooked strap member 26 therebetween The wire-mesh covered drill is then anodically cleaned, rinsed, dipped in muriatic acid, and rinsed in accordance with well-known cleaning practices The thus prepared object is then hung from the cathode bar 28 of a chromium plating bath 30 and surrounded by equidistantly spaced anodes 32. The chromium plating bath may be of any known industrial or engineering type Specifically, a bath containing thirty-two ounces per gallon of chromic acid and 0 32 ounce per gallon of sulphate in the form of sulphuric acid was used The bath was maintained at a temperature of 120 to 125 "F and plating carried out with a current density of 3 amperes per square inch For comparative purposes, a twist drill degreased and cleaned in the same manner, but without the wiremesh fabric B thereon, was also placed in the chromium plating bath. After three ( 3) minutes, both drills were removed from the tank The drill without the mesh-fabric was found to have "treed" on the cutting edges 12 and on the helical edge, designated 34, where the land and the flute of the drill meet The drill covered with the wire-mesh fabric, upon removal of the covering fabric, did not show any "treeing" whatever on either the cutting edges 12 or the edge 34 The cutting edges 12 and the edge 34 were covered with chromium, with the initially sharp edges just as sharply defined. Some chromium deposit appeared near the top of the flute. Additional drills were prepared as herein-before described and placed in the chromium plating bath under the described temperature and current density conditions for periods of five ( 5), ten ( 10), fifteen ( 15), thirty ( 30), forty-five ( 45), sixty ( 60), seventy-five ( 75), ninety ( 90), one hundred and five ( 105), one hundred and twenty ( 120), and one hundred and fifty ( 150) minutes After ten minutes in the tank, the flutes, as well as the land and edges 12 and 34 were completely covered with chromium, and the edges

12 and 34 were sharply defined with a conforming chromium deposit After thirty ( 30) minutes, there was, of course, a heavier chromium deposit, and in addition to complete coyerage of the entire body of the drill, the edges 12 and 34 were still sharply defined so that upon subsequent drilling with the tool, it performed excellently It was not until a specimen had been in the tank one hundred and fifty ( 150) minutes that marks of the mesh-fabric began to show on the land portion of the drill; but still there was no "treeing" on the edges 12 and 34. 785,189 understood that the invention is applicable to a wide variety of irregularly shaped objects The deformable, porous, electricallyconductive fabric or sheet has practically universal application in the sense that it can be used to cover the multi-planar area of practically any object, and with or without auxiliary holding means, may be supported upon the object itself. While the invention has been specificially described with regard to chromium plating, it will be understood that any plating solution having poor throwing power, or requiring relatively high current densities, may be used For example, the type of objects under consideration may be plated from a copper cyanide bath. The term "porous, electrically-conductive fabric" as used in the claims is intended to include woven wire-mesh fabric or a foraminous metal sheet formed by perforating or punching a continuous sheet. It is believed that the novel method and apparatus of the present invention, as well as the advantages thereof, will be apparent from the foregoing detailed description It will also be apparent that while the invention has been shown and described in several preferred forms, changes may be made in the 'method and structure disclosed without departing from the scope of the following claims.

* Sitemap * Accessibility * Legal notice * Terms of use * Last updated: 08.04.2015 * Worldwide Database * 5.8.23.4; 93p

* GB785190 (A)

Description: GB785190 (A) ? 1957-10-23

Improvements in laboratory and like benches having piped services

Description of GB785190 (A)

COMPLETE SPECIFICATION Improvements in Laboratory and like Benches having Piped Services We, GODFREY DICK PONSFORD and WAL TER GODFREY DICK PONSFORD, both British Subjects, of Fowler Road, Hainault, Essex, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention has reference to the construction of benches forlaboratories,kitchens and similar places in which such benches are fitted with taps and other consumption points connected to piped services such as water, steam and electric leads. It is the common practice to build or place the bench in its required position and then to lead the required piped services from the nearest fixed structure along a wall or walls, or under a floor, into or on to the bench, and as a consequence it is generally necessary to deface and make good wall and other structure and often to leave exposed unsightly runs of piping. Difficulties of this nature multiply as and when further bench sections with similar consumption points are added to an existing lay-out. It has been proposed to provide a type of unit for use as a bench or part of a bench for laboratories, kitchens and similar places which comprises a transportable pre - built section of convenient length having a bench top under which is fitted a plurality of service pipes running from end to end and connected intermediately to consumption points available on the bench top, the ends of said pipes being unioned or otherwise suitably formed for attachment to the ends of the pipes of an abutting unit This construction is referred to hereinafter as "the type described." By employing an assembly of units of the type described of requisite lengths they can be fitted end to end and their built-in service pipes interconnected to provide continuous service ducts throughout the bench assembly. As a consequence it is only necessary to connect one of the units by its pipes to the available services in or on the laboratory building structure, whereupon all bench unts connected thereto are at once fed by the services.

The present invention has for its object to simplify the construction of a main structure for bench units of the character described which will enable quick assembly from a minimum of parts and a sturdy finished article. Moreover, the structure according to the invention will permit speedy and easy access to the interior of the unit and in particular to the various service pipes. According to the invention, in a unit of the type described for use as a bench or part of a bench for laboratory, kitchen and similar places, there is provided a structure comprising a vertical back having a forwardly projecting right-angular side wing at or near each vertical end; a plurality of superimposed openings formed in said side wings to support horizontal service pipes extending between the side wings; an upper horizontal frame member supported in front of the back in spaced parallel relation thereto; a bottom horizontal frame member carried by the vertical back also at the front and also in spaced parallel relation to the back; a longitudinal recess in each horizontal frame member, said recesses facing one another; a front panel detachably inserted between said horizontal frame members and held by the recesses, and a bench top adapted to be secured between the top edges respectively of the vertical back and top horizontal frame member. The vertical back is preferably formed with a right-angular bottom flange projecting forwardly and having an upturned lip constituting the bottom horizontal frame member. The bench top would conveniently be an elongated rectangular plate having a downturned lip on its front edge to engage the upper horizontal frame member, and an upturned flange on its back edge, said flange being rearwardly lipped totengage the top edge of the vertical back, and said rectangu lar plate would be formed with a sink or sinks. In order that the said invention may be readily understood an embodiment thereof will be described by way of example with the aid of the accompanying drawings in which:- Figure 1 is a front elevation of the embodi ment; Figure 2 is an end view looking from the left of Figure I; Figure 3 is a plan; and Figure 4 is a perspective exploded view showing the three basic sections from which the structure is built up. Referring - - firstly - to Figure 4, there are- shown the three main parts constituting- the structure from which the

bench unit is built -up. - In the centre of the view will be seen a -part- comprising a vertical back sheet 1 to which are secured a pair of forwardly projecting side wings 2at right- angles to the -back and respectively disposed near the two vertical ends of the back. These side wings are preferably inset as shown from the vertical ends to prqvide a space within the con fnei- of -the back to house the union ends of service pipes hereinafter referred to, but in a modification the wings 2-may be disposed at the ends. The side wings 2 are formed with a plurality of superimposed openings 3 to support the said horizontal service pipes It is advantageous to make each opening with .a mouth at the front edge of the wing as illustrated whereby the appropriate pipe can be inserted from the front of the unit and thencradled--in the depression shown. In~ front of the back and carried by the brackets~4 secured to the back plate 1, is an upper horizontal frame member 5 disposed in spaced relation -to the back and vertically -underneath the same is a bottom horizontal frame member 6 also secured to the struc ture-at the front in spaced relation to the -back plate 1. - To -support the bottom frame -6 a right-angular bottom flange 7 is provided to the back 1 so as to project forwardly, and this-is- provided with an upturned lip to con -stitute then basis of the horizontal member 6, - Both the horizontal members 5 and 6 are formed with longitudinal recesses such as the slots 8 which face one another. On the right of Figure 4 is seen a front paneL 9 -whicfr can be inserted in the slots 8 so that it is detachably fixed in position to form the front of the structure. By making the rear walls of-the slots 8 slightly longer than the front walls, the insertion of ~the edges of the panel 9 is -facilitated. When the panel is in position, it may be held by a suit .able iusnber of readily removable screws. The third part of the structure is the bench -top 10- seen- to-the left of Figure 4. This is adapfed to be secured between the edge of the back plate 1 and the top horizontal mem ber 5. It is a narrow elongated rectangular

plate with a downturned lip 11 at the front to fit snugly against the member 5 and an upturned flange 12 at the back edge to lie against the top of the front face of the back plate 1. This upturned flange 12 is rear wardly lipped at 13 to rest on the top edge of the back-plate and a further bend 14 pro vides a low splash wall. The top of the brac kets 4 support the bench top 10 when it is fitted in place and a pair of lugs 15 are then secured to the brackets at 16. The assembly of the parts of the structure is seen in Figures 1-3 where reference numerals similar to those already employed -indicate the same parts.~ A typical set of service pipes are shown in position, and these are as follows: two electrical supply conduit tubes 17 and 18, gas pipe 19, compressed air pipe 20, hot water pipes 21 and 22 (fiow and return), cold water pipe 23, vacuum pipe 24, coolirig water pipe 25, telephone conduit 26 - and drain 27. The latter is received by and supported on brackets 32 which are vertically adjustable on the side wings 2 so that the .drain 27 can be given a variable degree of fall. As already mentioned, the pipes are cradled in the superimposed openings in the side wings 2 extending from end to end of the structure, and in the example, the particular unit~utilises only seven of the services (in cluding the drain) the remainder extending straight through, untapped, for use in other bench~ units. Hot and cald swan-neck water taps 28 are -erected on the bench top, one on each side of the sink 29, and if desired these may be pivoted to fold down flat on the bench when -not in use Four cocks 30 are mounted on The top horizontal frame member 5 to con nect respectively with gas, compressed air, yacuum, and cooling water, and the sink 29 drains off via a filter trap 31 to the drain pipe 27 What we claim is 1. A unit of the-type described for use as a-benck or part of a bench for laboratory, kitchen and similar places, comprising a ver tical - back having a forwardly projecting right-angular side wing at or near each ver-tical end; a plurality of

superimposed open:mgs~forme.d in said side wings to support horizontal service pipes extending between --the side wings; an upper horizontal frame -member supported in front of the back in spaced parallel relation thereto; a bottom horizontal frame member carried by the verjtical back also at the front and also in spaced parallel relation to the back; a longitudinal recess in each horizontal frame member, said -recesses facing one another; a front panel detachably inserted between said horizontal frame members and held by the recesses, and a bench top adapted to be secured between

* GB785191 (A)

Description: GB785191 (A) ? 1957-10-23

Hydrogenated spiramycins

Description of GB785191 (A)

PATENT SPECIFICATION : 7855191 Date of Application and filing Complete Specification: March 23, 1956. No 9220/56. Application made in France on April 13, 1955. Application made in France on Dec 1, 1955 Complete Specification Published: Oct 23, 1957. Index at acceptance:-Class 2 ( 3), AA 1 C 2 (A: C), AA 2 A 3. International Classification:-CO 7 g. f COMPLETE SPECIFICATION 1 Hydrogenated Spiramycins We, SOCIETE DES USINES CHIMIQUES RHONE-POULE Nc, a French body corporate, of 21 rue -Jean-Goujon, Paris 8 e, France, do hereby declare the invention for which we pray that a patent -may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to antibiotic substances and to their preparation In our Specification 758,726 there is described the

preparation-of an antibiotic to which has been given the name spiramycin, It is obtained by fermentation of the Streptomyces ambofaciens (NRRL No 2420); As stated in the said Application the product consists of three constituents of closely similar properties. These constituents in fact have distinguishing characteristics as follows, the compounds being named as Spiramycins I, II and III for convenienceand reference -Spiramycin I is a basic substance soluble in chlorinated solvents, alcohols, hexane, benzene, ketones, ethyl acetate and -amyl acetate and capable of forming salts with jacids, which basic substance contains the elements carbon, hydrogen, oxygen and nitrogen in substantially the following proportions by weight: Carbon 603 Hydrogen 87 Oxygen -28 5 Nitrogen 3 2 which basic substance displays, in ethyl alcohol solution a maximum absorption at 232 mt, has a molecular weight determined by -the ebullioscopic method: of about 800, a neutral equivalent of 463, a dissociation constant p K b of 7 7, a meltingpoint on the Maquenne block of 134-137 C, has zoptical rotations l 1 DJ 2 O in methanol (c= 1 %) of 96 , i ethanol (c= 11 %) of 91 and in chloroform (c= 1 i%) of _ 57 , and which in solid form exhibits characteristic absorption in -the infrared region of the spectrum at ithe following frequencies expressed in reciprocal centimetres: 3470, 2970, 2940, 1735,-1455, 1378, Pice 1317, 1275, 1237, 1160, 1122, 1090, 1052, 1015, 993, 905, 865, 840, 810, 782. Spiramycin II is a basic substance soluble in chlorinated solvents, alcohols, hexane, benzene, ketones, ethyl acetate and amyl acetate and capable of forming salts with acids, which basic substance contains -the elements carbon, hydrogen, oxygen and nitrogen in substantially the following proportions by weight: Carbon 616 Hydrogen 8 5 Oxygen 26 8 Nitrogen 3 1 which basic substance displays, in ethyl alcohol solution a maximum absorption at 232 my, has a molecular weight determined by the ebullioscopic method of about 800, a neutral equivalent of 464, a dissociation constanit p Kb of 7 6, a melting point on the Maquenne block of 130-133 _ C, has optical rotations lalD 20 in methanol (c= 1 li%) of 860, in ethanol (c = 1-%) of 800 and in chloroform (c= 1 %) of -550, and which in solid form exhibits characteristic absorption in the infra-red region of the spedtrum, at the following frequencies expressed in reciprocal centimetres: 3460, 2970, 2940, 1740, 1457, 1372, 1300, 1275, 1232, 1160, 1122, 1085, 1052, 1015, 993, 940, 905, 860, 840, 810, 782, 685. Spiramycin III is a basic substance soluble in chlorinated solvents, alcohols, hexane, benzene, ketones, ethyl acetate and amyl acetate and capable of forming salts with acids, which basic substance contains the elements carbon, hydrogen, oxygen and nitrogen -in substantially the following proportions by weight:

Carbon 61 Hydrogen 8 5 Oxygen 267 Nitrogen, 3 O which -basic substance displays, in ethyl alcohol solution a maximum absorption-at 232 mu, has a molecular weight determined by the ebullioscopic method of about 900, a, neutral equivalent of 473, a-dissociation constant p Kb of 7 6, a melting point on the Maquenne block 1 1 ' ; 1 1 1 11 -li I, 2 785,191 of 128-131 C, has optical rotations llD 20 in-methanol (c= 1 %) of 83 , in ethanol (c= 1 '%) of -790 and in chloroform (c= 1 %) of -50 , and which in solid form exhibits characteristic absorption in the infra-red region of the spectrum: at the following frequencies expressed in reciprocal centimetres: 3470, 2970, 2940, 1740, 1460, 1380, 1370, 1300, 1280, 1240, 1185, 1162, 1122, 1085, 1052, 1015, 995, 906, 865, 842, 810, 782, 695, 685. The term " spiramycin " is used generically in this application to mean the mixture of such spiramycins I, II and III which is obtained by the fermentation of Streptomyces ambofaciens (NRRL No 2420). It has now been found thlat the compounds obtained by the controlled hydrogenation of any of the -aforesaid products have antibacterial properties s-peeior to the product before hydrogenation -and according to the present invention a process for the production of antibiotic substances comprises hydrogenatinl spiramycin, or a constituent thereof ias hereinbefore defined, to introduce at most four hydrogen atoms into the spiramycin molecule, (of molecular weight 800-900) It is an-important feature of the present invention that the hydrogenation should be effected under conditions which permit of at most four hydrogen-atoms being added to the sp Miramycin molecule since the more highly hydrogenated products appear to be of little or no antibiotic value; According to the invention the spiramycin complex or any mixture of the spiramycin constituents is subjected, in the form of the base -or a salt -thereof, to catalytic hydrogenation The usual catalysts for such -hydrogenation may be employed e g -Raney nickel but it is preferred to -use a noble metal, e g palladium-or platinum as catalyst Thus using a palladium catalyst (supported for example on alumina, carbon-or-barium sulphate) it is found that -the absorption of hydrogen stops auto matically after four hydrogen-atoms have been absorbed pe molecule-of spiramycin or spiramycinu constituent Moreover in the case of the constituent spiramycin I there is a very sharp decrease in the rateof, absorption of hydrogen'willen'0 wo atons ha-ve been absorbed per molecule of spirarpyfiiin I, which much facilitates the preparation of dihydrospiramycin I since the reaction can be conveniently stopped at that stage The catalytic hydrogenation is preferably effected with the spiramycin complex or constituents in solution Various solvents which do pot themselves absorb hydrogen under the conditions of the hydrogenation may be employed, e g alcohols containing up to 4 carbon

atoms such as methyl alcohol 5 Othyl alcohol and isopropyl alqohol, ethers such as diethyl ether and dioxane, and esters such as ethyl acetate. The catalytic hydrogenation is preferably effected at normal pressure and room temperature since under these conditions it is easily controlled However other temperatures and pressures can 'be employed, though without 70 any advantage of importance. The following examples will serve to illustrate the invention but are not to be regarded as limiting it in any way Reference is made in the Examples to infra red absorption spectra 75 These are represented in the accompanying drawings in which the wavelengths have been plotted in microns (lower scale) and in reciprooal centimetres (upper scale) along the abscissae and the percentage transmission has been 80 plotted along the ordinates. EXAMPLE I. A solution of spiramycin ( 5 g) in ethanol ( 100 cc) containinng a suspension of a cataIyst ( 1 g) comprising 51 % palladium deposited 85 on alumina, is agitated in (an atmosphere of hydrogen After about 30 minutes the hydrogenation ceases when 275 cc of hydrogen have been absorbed The catalyst is filtered off and the solvent evaporated under vacuum at 90 ordinary temperature Tetrahydrospiramycin ( 4.8 g) is obtained as a white powder insoluble in water and very soluble in most organic 'solvents except petroleum ether. The produdt has the empirical formula 95 C 1-4 H 83-8 s O 15-1,N, and analysed as follows: C 60 6-6085 % E= 8 9 9 151 % Oi= 26,65 i% N= 3 05-3 l'% 100 It melted at 120-125 C_, its optical rotatory power was lal '= 71 50 (C= 1-%, methanol) and its ultra violet absorption showed, instead of the strong maximum at 232;ma characteristic of the parent spiramycin, 105 1 cm a weak maximum at 820 my, E = 14 (ethanol) Its-infra red absorption curve is shown in Figure 1 of the accompanying drawings and exhibits characteristic absorptions at the following frequencies expressed in reci 110 procal centimetres: 3470, 2930, 2800, 1730, 1620, 1462, 1453, 1410, 1372, 1318, 1289, 1270, 1232, 1182,-1160, 1120, 1075, 1050, 1015,991, 971, 956, 903, 841, 808, 783. EXAMPLE II 115 Spiramycin sulphate ( 5 g) in water ( 100 cc.) is hydrogenated using palladium on alumina-( 1 g) When the hydrogenation ceases die-catalyst is filtered off and tetrahydrospiramycin, sulphate is isolated by evaporating the 120 water under vacuum at ordinary temperature. The product -melted -at 1750 C, lJl'D = -58 7 (C= 1 %, methanol). EXAMPLE III. Spiramycin I ( 1 g) in ethanol ( 20 cc) is 125 hydrogenated in the presence of a palladium catalyst ( 0 2 g) -and the hydrogenation is

stopped when 27 cc of hydrogen have been 785,1191 Its infra red absorption curve is shown in Figure 4 of the accompanying drawings and exhibits characteristic absorptions at the following frequencies expressed in, reciprocal centimetres: 3470, 2930, 2800, 1730, 1720, 1462, 1455, 1410, 1370, 1330, 1318, 1289, 1273, 1238, 1182, 1160, 1122, 1080, 1065, 1050, 1015, 991, 965, 956, 903, 865, 841, 808, 783. EXAMPLE VI. By proceeding as in Example IV using spiramycin III as starting material there is obtained tetrahydrospiramycin III, m p 135-140 ' C. lal 7 J' 71 ' (c= 1 l%, methanol), ultra violet 1 cm absorbed which coincides with a very sharp decrease in the rate of absorption There is thus obtained dihydrospiramycin I ( 0 9 g), m.p 128-132 ' C lUlD 27 83 ' (ci% methanol). The compound conformed to the empirical formula C 4648 H 81,501 7 N 2 and analysed as follows: C = 60 45 i% H= 9 451 % 0 = 264. N= 32 % Its infra red absorption curve -is shown, in Figure 2 of the accompanying drawings, and exhibits characteristic absorptions at the following frequencies expressed in reciprocal centimetres: 3470, 2930, 2800, 1720, 1660,. 1462, 1453, 1410, 1378, 1320, 1272, 1240, 1184, 1160, 1122, 1075, 1060, 1050, 1015, 993, 965, 903, 868, 841, 808, 783. EXAMPLE IV. Proceeding as in Example III but continuing hydrogenation until no, more -hydrogen is absorbed, which is when 52 cc have been absorbed, there is obtained tetrahydrospiramycin I ( 0 8 g), m p 132-135 ' C la lD 2 '7 = -79 (c= 11 %, methanol), ultra violet ab1 cm sorption maximum 820 my, E = 14 li% (ethanol). The compound conformed to the empirical formula C 18 H 8,,7 01617 N, and analysed as follows: C= 60 251 % H= 9 Q% O = 26 9,% N= 3 05,% Its infra red absorption curve is shown in Figure 3 of the accompanying drawings, and exhibits characteristic absorptions at the following frequencies expressed in reciprocal centimetres: 3470, 2930, 2800, 1730, 1720, 1650, 1462, 1453, 1410, 1377, 1318, 1272, 1242, 1185, 1160, 1120, 1080, 1052, 1015, 991, 903, 841, 808, 783. EXAMPLE V, Spiramycin II ( 1 g) in ethanol ( 20 cc) is hydrogenated in the presence of 5 % palladium on alumina ( 0 2 g) until hydrogenation ceases which corresponds to the absorption of 52 cc. of hydrogen There is thus obtained tetrahydrospiramycin II ( 0 8 g) m p 125-128 ' C. ll D 27 63 (c= 1 i%, methanol), ultra violet 1 cm absorption maximum 820 mit, E = 14 1 %o (ethanol).

The compound conformed to the empirical formula C 4 48 H 8,_,7 011 _,N, and analysed as follows: C= 60 0 % H= 9 05 % 0 = 27 25 ^% N = 3 05 i% absorption maximum 820 mu, E = 14 (ethanol). The compound conforms to the empirical formula C 46 _ 4,H 8,,87 Ol,-,N 2 and analysed as follows: C= 59 75 i% 11 = 8 60 % 0 = 26 95 |% N= 2 91 % 85 Its infra red absorption curve hs shown in Figure 5 of the accompanying drawings and exhibits characteristic absorptions at the following frequencies expressed in reciprocal centimetres: 3470, 2930, 2800, 1740, 1730, 90 1640, 1462, 1453, 1410, 1375, 1315, 1290, 1270, 1230, 1182, 1160, 1120, 1075, 1050, 1018, 993, 965, 903, 860; 841, 808, 783. EXAMPLE VII. A mixture of spiramycins II -and III ( 10 g) 95 (containing about 50 % of each of the constituents) in ethanol ( 35 cc) is hydrogenated in the presence of a 5 i% palladium catalyst ( 2 g). Hydrogenation ceases when 540 cc of hydrogen have been absorbed The catalyst is fil 100 tered off and the alcohol is removed in vacuum There is obtained a mixture of tetrahydrospiramycins II nand III, which may be recrystallised from a mixture of cyclohexane and petroleum ether, m p 110-115 ' C 105 ltl,D= -63 ' (c= 1 % methanol). The mixed product conforms to the empirical formula C,648 H 8,,7 01516 N,> EXAMPLE VIII. "Adams' platinum" is prepared from the 1110 oxide ( 0 2 g) in alcohol ( 20 cc), spiramycin ( 1 g) is added iand the mixture hydrogenated until 50 cc have been absorbed This is equivalent ito about four atoms of hydrogen per molecule of spiramycin The operation takes 115 about 25 minutes There is thus obtained tetra hydrospiramycin ( 1 g), m p 120-125 ' C, i.e the same product as that of Example I. The tetrahydrospiramycins I, II and III also show, as the tetrahydrospiramycin complex, an 120 ultra violet absorption maximum at 820 myu, 1 cm E = 14 (ethanol). As stated above the hydrogenated spiraT 85,191, 1;,_% 785,1 I-91 mycins produced by the presenit invention have compared in vimrra with that of the parent spira, antibacterial properties superior to the bpira mycin mixture and the results, obtained in a mycins from which they are obtained The liquid medium, are set out in Table I which antibacterial spectrum of tetrahydrospiramnycin follows: (containing all three constituents) has been TABLE - Activity in mg/l Possible Tetrahydro j Strains Resistances Incubation spiramycin Spiramycin Staphy aureus 209 P ,,, B 3 = HB ,,,: Beau jon 3 Klebs pneumoniae ATCC 9997 Bac cereus ATCC 6,630 Micro citreus Sarc lutea ATCC 9341 Strept faecalis ATCC 9790 Strept viridans Diploc pneumoniae Til I P Neisseria catarrhalis Mycob sp ATCC Corynebact

pseudodiphteric. Brucella bronchisepticaBac mycoides Mycob phlei e , parasegmatis Penicillinstreptomycin streptothrycinstreptomycinneomycin Tetracyclines Tetracyclinchloramphenicolpenicillinstreptomycin Neomlycin Streptomycin 16 h at 370 + .1 3 h at 30 16 h at 370 haat 370 h at 370 + h at 37 O 16 h at 37 O 16 h at 37 O 2 5.4 2.15 2.15 -1.6 1.75 1.7 0.42 1 ' 0.64 2.3 1.5 10.3 275 58 6.8 1.44 245 = 1.4 3.5 1.6 1.6 1.6 2.7 5.1 0.8 3.1 0.2 10.3 38 3.5 2.3 166 , =,, 2700 R 607 , D, NR , SR 785191 The compounds have also been compared in vitro for their activity against stcaphylococcus aureus (strain FDA 209 P). The unit of activity selected is the smallest quantity of the purified product which, disTABL solved in 1 cc of an appropriate culture medium, prevents the development of staphylococcus aureus The results wre collected in Table II which follows: Product Activity in Units/mg. Dihydrospiramycin I 2,970 Tetrahydrospiramycin I 3,294 -3,245 III 2,960 , mixture 3,100 Spiramycin mixture about 3,000 The -toxicity of the tetrahydrospiramycin used in the form of the sulphate The mortality mixture in comparison with the spiramycin is noted over five days in respect of batches of mixture has been determined in the mouse by 10 mice The results are summarised in Table the subcutaneous route, the antibiotic being III which follows: TABLE III Doses in g/kg mouse s c Tetmhydrospiramycin Spiramycin 3 10/10 10/10 1.5 6/10 8/10 0.75 0/10 0/10 DL 50 s c 1 35 g/kg 1 25-g/kg The figure XDL, is the calculated dose which will cause the death of 50 % of the mice. The compounds have been further compared for their activity against streptococcal and pneumococcal peritonitis in the mouse. The products used in the form of the sulphate were administered (to batches of 10 mice) per or once a day for three days, commencing immediately after inoculation of the mice, in the peritoneum, with the organism 30 The mortalities are noted over eight days. Results are summarised in Table IV which follows: TABLE IV Daily doses in Organisms g/kg p o Tetrahydrospiramycin Spiramycin Streptococcus 1 0/10 1/10 0.3 2/10 1/10 0.1 9/10 8/10 DC 50 p o /day '0 215 g/kg 0 210 k/kg Pneumococcus 0 5 /00/10 Til 0.15 1/10 2/10 0.05 7/10 9/10 DC 50 p o /day 0 085 g/kg 0 105 g/kg 785,1917 The value of DGC,0 is-the calculated value for the amount of the compound which will effect the cure of 50 % of the mice.

* Sitemap * Accessibility * Legal notice

* Terms of use * Last updated: 08.04.2015 * Worldwide Database * 5.8.23.4; 93p

* GB785192 (A)

Description: GB785192 (A) ? 1957-10-23

Multi-shaft gas turbine plants

Description of GB785192 (A)

X 7 r_= 211 Dk\L?, PATENT SPECIFICATION Date of Application and filing Complete Specification: i March 27, 1956 No 9476/56. Application made in Switzerland on April 5, 1955. Complete Specification Published: Oct 23, 1957. Index at Acceptance:-Class 110 ( 3), G 5 (A: C 3 A: C 4: G), G 16, International Classification:-FO 2 c. COMPLETE SPECIFICATION. Multi-Shaft Gas Turbine Plants. We, SULZER FRERES, SOCIETE ANONYME, a Company organised under the Laws of Switzerland, of Winterthur, Switzerland, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to multi-shaft gas C 10 turbine plants of the kind in which a constant speed high pressure turbine supplying the useful output has connected in series with it a low pressure turbine which drives a compressor for the working medium, the outlet of the low pressure turbine is connected to the primary side of a heat exchanger while the outlet of the compressor is connected to the secondary side of this heat exchanger, and there is disposed between the secondary side of the heat exchanger and the inlet of the high pressure turbine a combustion chamber supplied with fuel through a regulating device. According to the present invention, in a multi-shaft gas turbine plant

of the kind specified, for regulating the output of the plant the angles of incidence of at least some guide blades of the compressor, which is of the axial flow type, are adjustable, and these blades and the regulating device for the fuel supply are arranged for adjustment together according to a predetermined function. Multi-shaft gas turbine plants are known in great number They are all characterised by having a machine group consisting of at least one turbine and at least one compressor connected together by a common shaft. For every condition of load on the plant each such group will run at a particular speed at which the plant -is thermodynamically in equilibrium. There are relatively few plants in which lPrice 3 s 6 d l the high pressure turbine provides the useful output It is much more common to use this turbine for driving the compressor for the combustion air The reason for this lies mainly in the fact that the plants of the former class have a less stable regulating behaviour and consequently there is greater risk of the compressor passing the surge line, whereas plants of the latter class have a considerably more stable regulating behaviour and are not so easily subject to compressor surge. When two turbines are connected in series difficult regulating problems generally arise on account of the different running characteristics of the high pressure and low pressure turbines, in that, for example, running the plant under part load produces a large variation in the relative outputs of the two turbines. Special measures must be taken to counteract this variation in the relative outputs, for which a number of suggestions have already been made In the literature there are up to now the following proposals for solving the regulating problem:(a) There is provided between the high pressure turbine and the low pressure turbine an additional combustion chamber, by which additional energy is supplied to the low pressure turbine. (b) Air is tapped off from the compressor at an intermediate stage and this is supplied through a second combustion chamber to the low pressure turbine. (c) An additional regulating system is provided consisting of by-pass pipes with regulating valves through which a part of the working medium is branched off before the high pressure turbine and is supplied direct to the low pressure turbine. In all these proposals it is fundamentally a question of correcting the variation in the 785,192 60. so 785,192 output ratio between the first and second however, for the solution of a regulating turbines problem that has hitherto been only incomIt has not been taken into consideration, pletely solved, and

with the hitherto unsushowever, that if only the output ratio is pected result that the efficiency of a gas corrected, at Dart load the compressor turbine plant working at hitherto unfavour 70 efficiency will drop very quickly to an able part load conditions is improved, extremely low value owing to its pressure represents a considerable advance in gas volume characteristic, and below a certain turbine technique. mass flow will pass the surge line Therefore The invention may be performed in the known regulating devices, even if they various ways, and one particular embodi 75 are on the whole successful in solving the ment, viz a twin shaft gas turbine plant, will regulating problem, cannot prevent the plant now be specifically described by way of from working very uneconomically at part example with reference to the accompanying load and, because of compressor surge, drawing which is a diagram of the plant. cannot be used to regulate the plant below In the plant shown in the drawing a high 80 a certain lower load limit pressure turbine 1 drives a load 2, in this The present invention arises from the case an electric synchronous generator, appreciation that the difficulties of regu through a first shaft 3 The low pressure lating such a plant must be removed with turbine 4 drives an axial flow compressor the aid of the compressor, it being necessary 6 for the combustion air through a second 85 to maintain the compressor efficiency as high shaft 5 The compressor 6 has adjustable as possible even in part load operation guide blades The speeds of the two shafts For better understanding, conditions in are entirely independent of each other and a twin shaft plant will now be considered the speed of the shaft 5 adjusts itself autoin which the high pressure turbine provides matically so that the plant is in equilibrium 90 the useful output and the low pressure In operation the combustion air enters the turbine drives the compressor It will be compressor 6 at the inlet 7 at atmospheric assumed that this plant is at first working pressure and after compression and preheatat its design point Should a slight reduc ing in the secondary side of a heat exchanger tion be made in the fuel supply this will 8 passes into a combustion chamber 9, to 95 effect a decrease in the inlet temperature which fuel is supplied through a pipe 11 of the turbines, the outputs of which will provided with a regulating device 10 The drop in consequence The compressor there fuel can be liouid or solid; it can also be fore runs more slowly and supplies a smaller gaseous and be delivered by means of a amount of air Thereupon the pressure special combustion gas compressor If the 100 drops-at the inlet of each turbine Hence, combustion gas compressor is driven in a their output is still further reduced, and as similar manner to the combustion air comthe relative drop in the pressure ratio across

pressor 6 by the low pressure turbine 4, for the low pressure turbine is greater than that example, it will be nrovided also with across the high -pressure turbine it suffers a adjustable guide blades because the same 105 greater relative loss of output Only at a considerations apply to this compressor as relatively low speed will the plant again to the combustion air compressor 6 The find an equilibrium point However, an hot working medium produced by the com. ordinary axial flow compressor comes very bustion of the fuel in the air flows first easily into surge, at about 70 to 80 % of the through the high pressure turbine 1 where 110 design speed Therefore it has not hitherto it partially expands, then flows through the been possible to regulate the plant to a part low pressure turbine 4 where it expands load operating point at which it requires further, then gives up heat in the primary less than about 65 % of the amount of air side of the heat exchanger 8, and finally required at the design point On the other leaves the plant 115 hand, however, the amount of air drops so By means of an adjusting device 12 and greatly in relation to the amount of fuel that, a mechanism 13 the guide blades of at least in spite of throttling the plant -at the inlet the first stages of the, compressor 6 can be to the high pressure turbine, the tempera adjusted and adapted to suit the prevailing a ture there remains constant or even conditions of operation Simultaneously 120 increases Because of this, however, the with the adjustment of the guide blades an thermo-dynamic conditions for a good part adjustment of the device 10 in the fuel load efficiency are present supply pipe 11 is effected through an impulse Now,-by virture of the present invention pipe or other connection 14 In this manner 00 it is possible to construct a plant which can exact conformity between the prevailing fuel 125 be operated with improved efficiency at part supply and the position of the adjustable load without regulating difficulties and with guide blades of the compressor is assured. out risk of surging Compressors with The twin shaft plant shown in the drawing adjustable blades and their characteristics is to be regarded simply -as an example In are sufficiently known per se To use them, the case of a greater number of turbines 130 785,192 connected in series, these can either be mounted on one of the two shafts connected to the load or to the compressor, or each additional turbine can be mounted on its own shaft In the latter case the compressor may be divided into several sections each of which is driven by its own turbine, or useful power can be obtained from two or more different shafts All these plants will fall in the scope of the invention provided the turbine of highest pressure produces useful output and provided the compressor or compressors have devices for adjusting the blade angle of guide blades at part load so that the position of

adjustment of the blades corresponds with the regulating position of the fuel regulating device.

* Sitemap * Accessibility * Legal notice * Terms of use * Last updated: 08.04.2015 * Worldwide Database * 5.8.23.4; 93p