Lesson Objectives

Introduction To :-

Types Of Motion

Linkages

Types Of Motion

Linear Motion

Rotary Motion

Reciprocating Motion

Oscillating Motion

Linkages

• What is a linkage ?

• How are they used ?

Before Starting With Linkage Kits

REVERSE MOTION LINKAGE:

As the top rod moves to the left the bottom

rod moves to the right. The bars move in

opposite directions. Another way of

describing this linkage is the direction of

movement in one rod is reversed in the

other rod. The fixed pivot is the centre of

rotation.

Walking Mechanism

PARALLEL MOTION LINKAGE:

As the large rod at the top of the diagram

moves to the left the two small rods at the bottom move to the

right. All the rods are parallel to each other.

PARALLEL MOTION LINKAGE:

TOOL BOX DRAWS: When the lid of the

tool box is opened an extra set of draws can

be 'unfolded'. This allows more tools to

be stored.

PARALLEL MOTION LINKAGE:

In 1784 Watt found a solution to his engine problems (which he

called "parallel motion") that was

developed in several different

configurations.

CRANK AND SLIDER LINKAGE:

The rods move forwards and

backwards in slider. The fixed pivot anchor

the linkages to one place.

CRANK AND SLIDER LINKAGE:

The crank which is the rotating disc, the slider which slides inside the tube and the connecting rod which joins the

parts together. As the slider moves to the right the

connecting rod pushes the wheel round for the first 180 degrees of wheel rotation. When the slider begins to

move back into the tube, the connecting rod pulls the

wheel  round to complete the rotation.

BELL CRANK LINKAGE:

This linkage allows horizontal movement

to be converted to vertical movement. It

also works the opposite way round. A practical example of

this is the brake mechanism on a

bicycle.

BELL CRANK LINKAGE:

BICYCLE BRAKES: Look at the diagram carefully. As the

brake lever on the bike is pulled the cable moves

upwards and forces the brake blocks against the rim of the wheel. Explain the type of

linkage involved - using notes and diagrams. Look at the page 'linkages' to help you

decide.

BELL CRANK LINKAGE:

From the SafeAir1 glider wing pushrod on the

aileron.

Clear use of a bell crank

Windscreen Wipers

Design a linkage to solve this problem – You cannot cross the wall

One Answer

Free Linkage Software

http://www.edu-ctr.pref.kanagawa.jp/LinkWeb/index_e.htm