Bell crank and lazy-tong linkages

Design and technology

This unit develops pupils' knowledge of mechanisms through levers and linkages. They will apply this knowledge by exploring mechanisms and incorporating them into an interactive book with a user-centred focus.

Levers and linkages: interactive books

Physical activity and equipment requiring safe use

Use of equipment that may require supervision for safety, e.g. scissors in KS1, needles, paint, knives, cooking.

so the levers can all make the same movements

Why do the pivot points on the levers of a lazy-tong linkage have to be in the same place on each lever?

Which two things do you need to use to safely make a hole for a pivot in cardboard?

In a bell crank linkage, what connects the levers to the central 'bell' shaped piece?

The output moves in the same direction as the input.

The output moves in the opposite direction to the input.

Works in the same way as the push pull linkage.

A movement needed to make something happen.

Which of these best describes a mechanism?

Which of these would be the most suitable for a pivot point in cardboard?

Fill in the missing word. A simple lever mechanism uses a __________ to reduce the effort needed to lift a load.

Which of these is NOT an example of a simple lever mechanism?

Content guidance

Risk assessment required - equipment

Adult supervision required

Introduction

What will you need for this lesson?

Are you ready to learn?

Equipment

Content guidance

Supervision

Worksheet