CHAPTER 2

LITERATURE REVIEW

2.1 Introduction

This second chapter will search about the literature that is relevant to

understand the brief ideas of smart roof tools. The first part of this review of the

literature will be describe about the ideas, the second part of the literature review will

describe about the history of the tools that we used in the product. The last part is

about the gap of study materials and the others method that we used to do this

product.

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2.2 Roof Tiles

Roof tiles are beautiful and durable but tiles can break. If you have a cracked

or broken tile you will need to replace it. When working on a roof you always need

to be aware of safety. If the roof is particularly steep or difficult to access you will

want to leave these repairs to professionals. They have the equipment and tools

necessary to do this work safely, which may be prohibitive to buy or rent for a one-

time repair. You also need to be careful not to damage any more tiles while doing the

repairs. When walking and working on tile roofs you can easily crack more tiles so

be certain not to apply too much force and step carefully and softly.

Roof tiles are designed mainly to keep out rain, and are traditionally made

from locally available materials such as terracotta or slate. Modern materials such

as concrete and plastic are also used and some clay tiles have a waterproof glaze. A

large number of shapes (or "profiles") of roof tiles have evolved. These include:

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Table 2.1: Type of Tiles

DIAGRAMS TYPE OF TILES

Flat tiles – the simplest type, which are laid in regular

overlapping rows. An example of this is the clay-

made "beaver-tail" tile (German Biberschwanz),

common in Southern Germany. Flat roof tiles are

usually made of clay but also may be made of stone,

wood, plastic, concrete, or solar cells.

Imbrex and tegula – an ancient Roman pattern of

curved and flat tiles that make rain channels on a

roof.

Roman tiles – flat in the middle, with

a concave curve at one end at a convex curve at the

other, to allow interlocking.

Pantiles – with an S-shaped profile, allowing adjacent

tiles to interlock. These result in a ridged pattern

resembling a ploughed field. An example of this is

the "double Roman" tile, dating from the late 19th

century in England and USA.

Interlocking roof tiles – similar to pantiles with side

and top locking to improve protection from water and

wind.

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Tables 2.1 shows the type of tiles that commonly used. Roof tiles are 'hung'

from the framework of a roof by fixing them with nails. The tiles are usually hung in

parallel rows, with each row overlapping the row below it to exclude rainwater and

to cover the nails that hold the row below. There are also roof tiles for special

positions, particularly where the planes of the several pitches meet. They include

ridge, hip and valley tiles. These can either be bedded and pointed in cement mortar

or mechanically fixed.

Similarly to roof tiling, tiling has been used to provide a protective weather

envelope to the sides of timber frame buildings. These are hung on laths nailed to

wall timbers, with tiles specially moulded to cover corners and jambs. Often these

tiles are shaped at the exposed end to give a decorative effect. Another form of this is

the so-called mathematical tile, which was hung on laths, nailed and then grouted.

This form of tiling gives an imitation of brickwork and was developed to give the

appearance of brick, but avoided the brick taxes of the 18th century. Slate roof tiles

were traditional in some areas near sources of supply, and gave thin and light tiles

when the slate was split into its natural layers. It is no longer a cheap material,

however, and is now less common.

2.3 History of Roof Tiles

The spread of the roof tile technique has to be viewed in connection with the

simultaneous rise of monumental architecture in ancient Greece. Only the newly

appearing stone walls, which were replacing the earlier mud brick and wood walls,

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were strong enough to support the weight of a tiled roof. As a side-effect, it has been

assumed that the new stone and tile construction also ushered in the end of 'Chinese

roof' (Knickdach) construction in Greek architecture, as they made the need for an

extended roof as rain protection for the mud brick walls obsolete.

Production of dutch roof tiles started in the 14th century when city rulers

required the use of fireproof materials. At the time, most houses were made of wood

and had thatch roofing, which would often cause fires to quickly spread. To satisfy

demand, many small roof tile makers began to produce roof tiles by hand. Many of

these small factories were built near rivers where there was a ready source of clay

and cheap transport.

2.4 Concrete Roof Tiles

Figure 2.1, Figure 2.2, and Figure 2.3, shows example of concrete roof tiles.

Our study is focused on the Concrete Roof Tiles which is that have standard size

long 42 cm , broad 11.5 cm and heavy 4kg. Smart Roof Tools is designed to help to

lift up the concrete roof tiles and facilitate the process of replacing concrete roof tile

that had broken or break.

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Example of the Concrete Roof tiles:

Figure 2.1 : Brown Concrete Roof Tiles

Figure 2.2 : Side View Arrangment of Tiles

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Figure 2.3 : Top View Arrangement of Tiles

2.5 Ideas

To produce smart roof tools, we make a lot of research on the internet and

picking up some books at the library. We find a lot of information and a lot of

exchange opinions with each other guided by the information available, we combine

the tools of the same functions for these tools to produce smart roof tools. Using all

applications such as bottle openers, hydraulic jack can be used as a guideline to

produce the product.

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2.4.1 Same concept of tools

Table 2.2 shows type of tools that have same concept method used by our

product. Roof tiles usually brought about from cement leakage pasted on the ridge is

broken or cracked tiles away from the original position (displaced or move or fall).

For example, same tools with a smart concept roof tools, it also uses hand tools

applications such as spanner, pliers, pry bars, hydraulic jack, bottle openers and

more. All the devices have the same concept. There are those example of the same

application that we used.

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Table 2.2 Type of Tools With Same Method Used

TOOLS GENERAL

Bottle opener

Is a device that enables the removal of metal bottle

caps from bottles. More generally, it might be

thought to include corkscrews used to remove cork..

A bottle opener is a specialized lever inserted beneath

the pleated metalwork, which uses a point on the

bottle cap as a fulcrum on which to pivot.

Hydraulic jack

Hydraulic jacks are typically used for shop work,

rather than as an emergency jack to be carried with

the vehicle. Use of jacks not designed for a specific

vehicle requires more than the usual care in selecting

ground conditions, the jacking point on the vehicle,

and to ensure stability when the jack is extended.

Hydraulic jacks are often used to lift elevators in low

and medium rise buildings. A hydraulic jack uses a

fluid, which is incompressible, that is forced into a

cylinder by a pump plunger.

Pry bars

It is used as a lever either to force apart two objects

or to remove nails. Pry bars are commonly used to

open nailed wooden crates. Common uses for larger

crowbars are: removing nails, prying apart boards,

and generally breaking things. Pry bars can be used

as any of the three lever classes but the curved end is

usually used as a first-class lever, and the flat end as

a second class lever.

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pliers

Pliers are a similar tool with a different type of head

used for cutting and pulling, rather than squeezing.

Tools which are effectively pliers designed

principally for safely handling hot objects are usually

called tongs. Special tools for making crimp

connections in electrical and electronic applications

are often called "crimping pliers"; each type of

connection uses its own dedicated tool.

Spanner

Is a tool to provide grip and mechanical advantage in

applying torque to turn objects. Usually rotary

fasteners, such as nuts and bolt or keep them from

turning.

2.6 Materials and Components

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2.5.1 Mechanical Spring:

Figure 2.4: Mechanical Spring

Figure 2.4 shows example of mechanical spring that we used. A spring is

an elastic object used to store mechanical energy. Springs are usually made out

of spring steel. There are a large number of spring designs; in everyday usage the

term often refers to coil springs. Small springs can be wound from pre-hardened

stock, while larger ones are made from annealed steel and hardened after

fabrication.

Some non-ferrous metals are also used including phosphor

bronze and titanium for parts requiring corrosion resistance and beryllium

copper for springs carrying electrical current (because of its low electrical

resistance).

When a coil spring is compressed or stretched slightly from rest, the force it

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exerts is approximately proportional to its change in length (this approximation

breaks down for larger deflections). The rate or spring constant of a spring is the

change in the force it exerts, divided by the change in deflection of the spring.

That is, it is the gradient of the force versus deflection curve.

An extension or compression spring has units of force divided by distance, for

example lbf/in or N/m. Torsion springs have units of torque divided by angle,

such as N·m/rad or ft·lbf/degree. The inverse of spring rate is compliance, that is:

if a spring has a rate of 10 N/mm, it has a compliance of 0.1 mm/N. The stiffness

(or rate) of springs in parallel is additive, as is the compliance of springs in series.

Simple non-coiled springs were used throughout human history e.g.,

the bow (and arrow). In the Bronze Age more sophisticated spring devices were

used, as shown by the spread of tweezers in many cultures. Ctesibius of

Alexandria developed a method for making bronze with spring-like

characteristics by producing an alloy of bronze with an increased proportion of

tin, and then hardening it by hammering after it was cast. Coiled springs appeared

early in the 15th century, in door locks. The first spring powered-clocks appeared

in that century and evolved into the first large watches by the 16th century.In

1676 British physicist Robert Hooke discovered Hooke's law which states that

the force a spring exerts is proportional to its extension.

A compression spring is a spring that will produce linear force by pushing

back against forces that are applied to it. A weight or force will cause the

compression spring to compress down, and if the spring is designed correctly the

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spring will push back against the weight causing it to return to its original state.

Extension springs are attached at both ends to other components. When these

components move apart, the spring tries to bring them together again. Extension

springs absorb and store energy as well as create a resistance to a pulling force. It

is initial tension that determines how tightly together an extension spring is

coiled.

This initial tension can be manipulated to achieve the load requirements of a

particular application. Extension Springs are wound to oppose extension. They

are often tightly wound in the no-load position and have hooks, eyes, or other

interface geometry at the ends to attach to the components they connect. They are

frequently used to provide return force to components that extend in the actuated

position. A torsion spring is a spring that works by torsion or twisting; that is, a

flexible elastic object that stores mechanical energy when it is twisted. When it is

twisted, it exerts a force (actually torque) in the opposite direction, proportional

to the amount (angle) it is twisted. There are two types. A torsion bar is a straight

bar of metal or rubber that is subjected to twisting (shear stress) about its axis by

torque applied at its ends. A more delicate form used in sensitive instruments,

called a torsion fiber consists of a fiber of silk, glass, or quartz under tension that

is twisted about its axis. The other type, a helical torsion spring, is a metal rod or

wire in the shape of a helix (coil) that is subjected to twisting about the axis of

the coil by sideways forces (bending moments) applied to its ends, twisting the

coil tighter.

2.5.2 Iron Plate

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Figure 2.5 : Iron Plate

Figure 2.3 shows example of iron plate that we used. Iron is an element in the

periodic table that has the symbol Fe and atomic number 26. Iron is a metal that is in

a group 8 and period (period) 4. Iron is a metal extracted from iron ore, and is rarely

found in a free element. To obtain elemental iron, the impurities must be removed by

chemical reduction. Iron is used in the production of steel, which is not an element

but alloys, compounds of different metals (and some non-metals, notably carbon).

Iron is one of the most common elements on Earth, up 5% of the Earth's

crust. Most of the iron is present in various types of iron oxide, such as mineral

hematite, magnetite, and takonit. Most of the Earth's core is believed to contain iron-

nickel alloys. About 5% of meteorites also contain iron-nickel alloys. Although rare,

this is the main form of natural metallic iron on the surface of the earth.

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In the industry, Iron is mostly hematite (Fe2O3 bit) and magnetite (Fe3O4),

by lowering the furnace blowers carbon (blast furnace) at a temperature of around

2000 ° C. Furnace blowers, iron ore, carbon in the form of coke, and a flux such as

limestone filled at the top of the furnace, while a spray of hot air forced into the

furnace at the bottom.

I. Cast iron

Contains 2 % - 3.5 % carbon and small amounts of manganese. Contaminants

present in pig iron that negatively affect material properties. It has a melting point in

the range of 1420-1470 K, which is lower than the two main components, and makes

it the first product that melted when carbon and iron are heated together. Mechanical

properties vary, depending on the form of carbon that is incorporated into the alloy.

II. Wrought Iron

Contains less than 0.5% carbon. It is hard, malleable, and not as fusible as pig

iron. It has a small amount of carbon, a few tenths of a percent. If sharpened a taper,

it quickly loses its sharpness.

III. Iron Alloy

Carbon content changing and also other metals, such as chromium,

vanadium , molybdenum , nickel , and tungsten.

IV. Carbon steel

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Contains between 0.5% and 1.5 % carbon, with small amounts of manganese,

sulfur, phosphorus, and silicon. In a production tool, we use steel plate as a key

component of our tool. Steel plate is used as a body (body) tool to support the load to

be lifted. We chose the steel plate because it is widely available and easy to solder to

incorporate certain parts.

2.5.3 Bolt and Nuts :

Figure 2.6 : Bolt and nut

Figure 2.6 shows example bolt and nut. Screws can be defined as an inclined

plane around a central axis. Where inclined planes shaped and spiral threads around

(circling) vertically upwards, with a wedge at the end.

At first, only made of wood screws are used as fasteners for tool listed the

object. Then, by the passage of time and the development of technology around the

world, when the material to produce found, screws were invented. There are different

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types of screws can we get instances of the creation of the screw can facilitate the

construction business and others.

i) Type of bolts

There are several types of bolts

Chipboards screw

Particle board screw

Concrete screw

Self-tapping screw

In civil engineering, the screw is defined as a binder or a binder machine to

combine two different objects. Screw has two main functions. The first function, it is

used to hold and install several objects together. The second function, the screws

used to exert a force on an object. As examples of the pipes, tools and vise.

2.7 Design Method

2.6.1 Joining method

Connection process is a process in which two or more elements connected to

a single part or component. There are few ways which connections can be made.

Connection process can be classified into several categories as follows that is

Brazing Welding. The selection of a particular type of connection depends on several

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factors relating to the connection such as Design of the parts of the tools and

economic.

2.6.2 Ways of connecting

i) Welding

Welding is a process of permanent connections. This joining process

involve the melting of the base metal in the local area is connected and also involves

the melting of the filler metal. Strength equals the strength of the resulting extension

of the parent metal. Types of welding process is fusion welding and solid state

welding.

ii) Brazing

Fusion brazing fusion zone, causing the metal connecting the parent

and filler metal, better known as the electrodes. Solid state welding filler metal or not

use electrodes but instead it only uses heat and pressure only, such as spot welding

and friction welding.

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