Focus on Inventions

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Inventions

Copyright Š 2010 Top That! Publishing plc Tide Mill Way, Woodbridge, Suffolk, IP12 1AP, UK www.topthatpublishing.com Top That! is a trademark of Top That! Publishing plc All rights reserved

CONTENTS Washing Machine Pages 4–6

Iron Pages 7–9

Microwave Pages 10–12

Airbag Pages 13–15

Sewing Machine Pages 16–18

Toaster Pages 19–21

Refrigerator Pages 22–23

Petrol Engine Pages 24–26

Steam Engine Pages 27–29

Gearbox Pages 32–34

Jet Engine Pages 30–31

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CONTENTS Computer Pages 35–37

Digital Versatile Discs Pages 38–39

Radio Pages 44–45

Calculator Pages 46–48

Light Bulb Pages 52–53

Camera Pages 54–56

Television Pages 40–41

Satellites Pages 42–43

Telephone Pages 49–51

X-Ray Machine Pages 57–59

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Microphone Pages 60–61

WASHING MACHINE It’s pretty simple to operate a modern washing machine; just place your clothes in the front, add soap powder into the little drawer, make sure the setting isn’t too hot (or it will shrink your favourite jumper), and press the ‘on’ switch. What goes on inside the machine, however, is quite amazing.

What’s inside a washing machine In most modern machines all you can see inside is a big metal cylinder, which is where the washing goes. In some older machines there will be a twisted plastic pole that moves the clothes around to make sure they get really clean. Look at the pictures to see the main parts that make the machine work.

Inner cylinder – clothes are held inside here

Motor – an electronically powered motor turns a spindle, which is attached to a belt that turns the cylinder around

Outer cylinder – this is attached to the body of the washing machine, and mounted to let the inner cylinder shake inside without bashing into any other parts. It also seals in the water.

4

Pipe – takes away all the water from the cylinders and discharges it safely

Valves – the two valves feed into the one pipe. If the highest temperature setting is selected, then the ‘hot’ valve opens. If a cool setting is chosen, then the ‘cold’ one opens instead. If you need warm water, then they both open simultaneously

Concrete block for stabilising

5

Pump – this moves water in and out of the outer cylinder as needed

What’s the spin cycle When you spin a container of liquid around really fast, the liquid moves to the sides of the container. Try it (outside) with a bucket about a third full of water. Spin it around repeatedly with your arm outstretched – if you do this fast enough, the water won’t spill out because it is ‘clinging’ to the sides of the bucket. When the inner and outer cylinders of a washing machine spin, the water moves to the edge and is removed by pipes, which makes your clothes a little drier.

Soaking dissolves the dirt

How do clothes get clean Soaking clothes in warm, soapy water makes the dirt dissolve and float off the material. Swooshing them around at the same time speeds up the process and also helps to move the dirt away from the clothes.

Changing the dirty water for clean water carries off the dissolved dirt and gives any remaining dirt another chance to be cleaned off the clothes.

Rotating action lifts dirt from clothes

FACT BYTES The average washing machine has a capacity (holds when full) of around 5.5 kg (12 lb) of clothes.

That’s around 55 pairs of socks!

The reason washing machines are so heavy is that a large block of concrete needs to be attached from the main frame to counterbalance the force of the washing being moved around and around, especially when the machine is spinning the clothes.

Clean water flushes dirt away

6

IRON Without the modern iron, ironing our clothes would be a long, messy and even dangerous process! Before the introduction of electricity, heavy lumps of metal, heated by the fire, were run over clean clothes, but they often left behind a line of dirt in the process.

Who invented the electric iron The first electric iron is credited to Henry W. Seely of New York in 1882. In the same year, a French company created an iron that was heated by an arc (semicircle) made of carbon, but this was highly dangerous, and in 1892, both Crompton and Co. and the General Electric Company managed to create a relatively safe electric model. It set an industry standard for many years, being made from only four metal components, and a wooden handle and some electronic parts.

A housemaid uses an electric iron on a lace doily in this advertisement from General Electric

FACT BYTES

Why does steam help ironing

By 1939, the electric iron had become the second-most popular household appliance (number one was the radio).

Steam combined with the heat and weight of the iron helps to stretch out the molecules in your clothes, smoothing away any creases – but you don’t want wet clothes! That’s why the water to make the steam is passed through tiny holes in the hot base of the iron – it turns into steam before it gets the chance to make your clothes soaking wet again.

Some weird and wacky irons have been invented since 1882 – one model had cords that plugged into electric ironing boards! The travel iron, friend of the business traveller and holidaymaker alike, is a particularly lightweight version that can run on a 120-volt power supply.

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How does the thermostat work

What’s inside an iron The main part of an iron is the heating element, like that in an electric oven, which makes it hot. An iron also needs a metal base, a thermostat (to stop the iron overheating and burning your clothes) and a control button to set it to the right temperature.

Metals expand at different temperatures, so two strips of metal, made from different types, are fixed together.

The strip that expands more forces the other strip to bend. When the iron goes above the temperature setting you want, this metal strip bends so much that it moves, breaking the electrical circuit. The flow of electricity stops so the iron cools down.

Element – causes the base of the iron to heat up

Hot plate – this is coated

Water tank – fill a little

Thermostat – a heat

Control button –

in a special alloy (mix) of

plastic jug with water

sensitive strip cuts the

you can set this to

metals, which helps to

and pour it into the hole

power supply as soon as

the temperature

prevent the metal

at the front of the iron.

the chosen temperature

most suitable for

sticking to clothes. It also

The water will run down

is reached, and the

the fabric that you

helps the iron to glide

a tube and fill up the

current returns when the

want to iron

over clothes as smoothly

tank. The water is heated

iron has cooled down

as possible

to create steam

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