PATENTS

August 2011 Sealing Technology13

Brush seal with stress and deflection accommodating membrane

Applicant: Sealeze, a unit ofJason Inc, USAA brush seal is described that is designed to be used in high-temperature sealing applications. It has brush bristles and a sealing membrane, accommodating a construction that is capable of longitudinal extensibility when subjected to stress, strain and/or deformation. The membrane has one portion that overlaps another portion in at least one direction. This overlap can slide to enable relative movement, which helps to accommodate stress, strain and/or deflection during manufacture, use and operation.Patent number: WO/2011/025558Inventors: P. Fitzgerald, R. Ferrymanand P. FitzgeraldPublication date: 3 March 2011

Pipe clamp with sleeve and gasket

Applicant: Norma USHolding Llc, USAThis patent covers a pipe clamp that includes a band; a tightening mechanism for the band; a split sleeve within the band; and a gasket located inside a circumferential channel in the split sleeve. The split sleeve includes a tongue-and-groove joint in which the tongue has at least one side edge that confronts and engages a side edge of the groove during penetration of the tongue into the groove (in response to

tightening of the outer band using a fastening mechanism). This provides a metal-to-metal seal at the tongue-and-groove joint. The rela-tive construction of the tongue and groove is such that during penetration of the tongue into the groove there are areas of spaced sepa-ration between the confronting side edges of the tongue and groove. In addition, during tightening, the gasket is forced into these areas of spaced separation which provides a second, gasketed seal at the tongue-and-groove joint. (This design is probably used in exhaust pipes although this is not mentioned in the patent.)Patent number: WO/2011/025935Inventors: B.T. Geese and B.T. IgnaczakPublication date: 3 March 2011

Synergic surface modification for a bearing seal

Applicant: Baker Hughes Inc, USAThis patent covers what are known as ‘metal face seals’ for earth-boring bit bearings. These seals are an adaptation of the well known duo-cone seal used in earth-moving equipment. In one embodi-ment of this invention, a thin-film coating with a textured surface is formed on the seal face. This textured surface may be first formed on the rigid sealing ring itself using mechanical techniques, chemical etching or laser machining. The textured surface may contain pores that have a diameter of, for example, 100 μm and a depth of 5–7 μm. The thin-film coating may be a hard coating, such as diamond-like carbon or an alloy of aluminium-magnesium boron. It may be very thin, with

a thickness of, for example, 1–5 μm. The pore density may be 20–30%. In some embodiments, the depth of the pores is greater than the thick-ness of the coating – thus exposing the rigid seal face through the coating. The texture promotes hydrodynamic pressure, lowers face torque and temperature, and traps wear debris, while the thin, hard coating protects the texture from being worn out by the asperity contact.Patent number: WO/2011/028427Inventors: C. Lin and A. DickPublication date: 10 March 2011

Screwed pipe joint

Applicant: Voss FluidGmbH, GermanyThis invention relates to a screwed pipe connection with a tapered metal-to-metal joint. The method of manufacturing the joint and the detail of the form of the tapered connection are described in detail. A feature of this design is the change in cross-section of the tapered part of the pipe-end.Patent number: WO/2011/029687Inventors: G. Berghaus and H. PottPublication date: 17 March 2011

Technical Editor’s comment: This presumably has an effect on the relative elastic deflections as the joint is assembled.

Thrust face for a seal

Applicant: Aktiebolaget SKF, SwedenThis invention relates to a component (13) described as a thrust face for a seal (11). This is effectively a metal sleeve for the seal, which is deformed against the shoulder on a shaft. The structure of the component material is designed in such a way that its strength increases when it is deformed (see figure on page 14).Patent number: WO/2011/029746Inventor: J. KurthPublication date: 17 March 2011

An example of a metal face seal for earth-boring bit bearings. A surface treatment may be described on the seal face using mechanical techniques, chemical etching or laser machining (patent WO/2011/028427).

This patent (WO/2011/025935) covers a pipe clamp. The illustrations show the action of the metal joint and also the gasket lining.