On the post-it note in front of you have 30 seconds to

independently write down your answer/thoughts on the BIG

QUESTION!

IMPORTANT – Come and stick your answer to the board !

What are Mechanisms & How do they

Make Our Lives easier?

Mechanisms ?

• To answer the BIG Question, What are

Mechanisms and how do they work?

• To develop knowledge of products that use

these mechanisms.

• To understand how mechanisms make our

lives easier.

I will be able to list some examples of mechanisms. I will

recognise how mechanisms make our life easier and give some examples of products that use mechanisms. (Level 6)

I will discuss some mechanisms in detail. I will be able

to explain why mechanisms are used. I will explore the

real life application of mechanisms (Level 7)

I will be able to explain in detail what mechanisms are

and why they are used. I will identify independently the

mechanisms that products use, how they work and

make life easier. (Level 8 )

Some Learning Outcomes could be…..

Whilst thinking about it is your challenge to :

Spend One Minute on each table to individually collect information about

each type of mechanism.

Fill in your Big challenge sheet as you go around with information about :

How the Mechanism works (you could draw and label)

Products that use this mechanism.

How the Mechanism makes our lives easier.

What is a Mechanism?

Creates Movement!

A device that uses forces and movement. = The Input

forces and movement. = The Output

Mechanisms usually consist of moving parts such as : Gears , Linkages , Belt and Chains and Followers.

Mechanisms Make Life Easier and more comfortable!

Transmits energy in the form of Movement.

The technological

advances humans

have made through the

ages, have been

closely linked with their

ability to harness

energy and use it to

perform mechanical

work.

Although humans are

very clever creatures,

our size, structure and

muscles put severe

limitations on what we

can do. –

MECHANISMS HELP!

One of the oldest mechanisms is

the lever. Stone Age people used

them to move large objects.

Put your hands either side

of your face.

Move your Jaw up and

down. – Your Jaw is a

Lever!

Levers can be used in addition to

human muscles; they help humans to

do jobs which could not be done

otherwise because of their limited

strength.

A lever makes

life easier for

use! - Moving

things. , Lifting

things

Levers are an essential part of many

mechanisms. They can be used to change the

amount, the strength and the direction of

movement.

Like a see-saw or balance, the load

and the force work together. As one

moves up the other moves down.

Linkages = Lots of Levers joined together!

The Pivot! = the

center point of

the lever system

Linkages are an essential part of

many mechanisms. They can be

used to change direction, alter

speed and change the timing of

moving parts.

Lever and Linkage Examples!

Scissors

Garden

Shears –

The longer

the handles

the bigger

the force

applied!

Our Body has many

Lever mechanisms!

Arm , Neck , Jaw ,

Legs

The crank is used to

convert/change rotary motion

to reciprocating or oscillating

motion.

With careful timing it can also

be used to convert motion the

other way... from reciprocating

to rotary.

Rotary = Movement

in a circular motion

Reciprocating =

movement

backwards and

forwards or up and

down.

Oscillating =

Movement from side

to side in a half circle

motion e.g. A

grandfather clock

pendulum

Mechanical Pencil Sharpener

When you turn the handle with a ROTARY motion the people move up and down =RECIPROCATING

Manually operated car window

A Fishing Rod Reel

Crank system –foot pedal on Sewing Machine.

Crank set on a bike converts reciprocating motion of the riders legs into rotational motion to drive the chain.

Gears are used to change speed in

rotational movement.

In the example above the blue gear has

eleven teeth and the orange gear has

twenty five. To turn the orange gear one full

turn the blue gear must turn 2.27 turns.

Gears turn in alternate directions.

gears turning in the

same direction would not

be able to turn, the gears

would lock together.

Have a go

with the

gears

example

on your

table !

A gear is different from a pulley in that

a gear is a round wheel which has

linkages

Bevel gears can be used to

change the direction of drive in a gear

system by 90 degrees. A good

example is seen as the main

mechanism for a hand drill.

As the handle of the drill is turned in a

vertical direction, the bevel gears

change the rotation of the chuck to a

horizontal rotation.

Non-digital Clock

Gears!

Bicycle Gears

A worm gear is a type of gear used

to reduce speed. For each complete

turn of the worm the gear advances

only one tooth of the gear.

Hand Whisk/Egg

Beater

Can opener gears

A simple pulley. As the rope is pulled down

the weight moves up by the same distance.

Compound pulley - The rope is

wrapped around two pulleys. As the

rope is pulled the weight, this time

attached to the lower pulley rather

than direct to the rope, moves up

slower than the speed that the rope is

pulled.

By wrapping the rope several times

around the pulleys it is easily

possible to lift your own weight off

the ground!

A pulley is a wheel on an axle that is

designed to support movement of a

cable or belt along its circumference.

Pulley systems can be used to lift

weights safely and effectively

In general a single pulley is useful as it

allows the worker to lift the weight without

bending his back. This means it is much

safer to lift the weight.

Pulleys are used in a variety of ways to

lift loads, apply forces, and to transmit

power.

Belt and Pulley System e.g. A

conveyer belt at a supermarket.

Pulleys

used on

boats.

Pulley

systems for

rock

climbing

equipment

Pulley System on Window Blinds

Pulley System to open and close garage doors.

Cranes using Pulley Systems (not to lift elephants!)

Pulley on a Well

Large Pulley Systems. – e.g. A Ski lift system.

used to convert between rotary and

linear motion.

the pinion is the gear.

Rack and pinion can convert from rotary to linear or from linear to rotary.

The rack is the flat, toothed part.

The diameter of the gear determines

the speed that the rack moves as the

pinion turns.

Rack and pinions are commonly used

in the steering system of cars to

convert the rotary motion of the

steering wheel to the side to side

motion in the wheels.

Pillar Drill : As the handle is turned the

table moves up and down the central

pillar of the drill. This makes it easy to

move the table and takes the

minimum of effort.

The rack and pinion reduces the force

needed to move the table and most

importantly protects the machine operator

and his/her back from excessive strain.

A good example of a ‘rack and pinion’

gear system can be seen on trains

that are designed to travel up steep

inclines.

The wheels on a train are steel and

they have no way of griping the steel

track. - The Rack and Pinion creates good grip.

A good example of a ‘rack and pinion’

train is seen in the Snowdonia National

Park (North Wales). Mount Snowdon is

the highest mountain in Wales.

Rack and pinion

gears are also

used in some

scales to turn the

dial that displays

your weight.

Chains are used to connect gears. They

work in a similar way to pulleys but with a

positive drive rather than a reliance on

friction.

Gears which are connected by chain turn

in the same direction unlike gears which

mesh against each other.

Like gears, chain and sprocket drives

are used to transmit rotary

motion from one place to another

Unlike gears however, the direction of

rotation for any wheels within the chain is

the same.

Also unlike gears, the wheels do not

touch, they can be as far apart as the

chain allows.

Gears driven by chains are used in

machinery, motorcycles, bicycles , in

car engines and have many more

applications.

Caterpillar Tank !

Movie Projector!

What are Mechanisms & How do they

Make Our Lives easier?

Write a New

Post-it Note

with a new

answer to the

BIG

QUESTION!

• Pivot

• Linkage ( Link up Levers)

• Lever

• Gears

• Rack and Pinion

• Chain and Sprocket

• Cranks

• Pulleys

• Make Life Easier

• Force

• Motion

• Movement

• Machines

• Help Human Power

• Stone Age

• Bike chain

• Window Blinds

Scissors

Nut crackers

Arm

Jaw mechanism

See-saw

Motions :

Linear

Rotary

Reciprocating

Oscillating