Mechanisms Levers Linkages GCSE Graphic Products The principles

Mechanisms, Levers & Linkages GCSE Graphic Products

The principles of simple mechanisms Learning Objectives By the end of this lesson you will have developed a knowledge and understanding of: – the principles of simple mechanisms and identify the relevant components and features – levers and linkages.

The principles of simple mechanisms • A mechanism creates movement within a product. • There will be occasions when the graphic designer needs to include a mechanism in a product, whether it be a board game or a moving sign.

Movement Description Linear Moving in one direct Reciprocal / reciprocating Moving back and forth Rotary Turning in a circular motion Oscillating Swinging side to side in alternate directions Diagram

The lever • The lever is the simplest of mechanism. • A lever is a device that pivots around a point called the fulcrum. • When a force is applied to one side, the other side moves in the opposite direction. • By positioning the fulcrum the outputting force can be magnified, or diminished. • The speed and distance of the movement can also be magnified, or diminished. AQA GCSE Design and Technology: graphic products

Types of lever Levers can be categorised as one of three types: Type of lever Description Diagram Product Class 1 The force/effort and the load are on opposite sides of the fulcrum Seesaw Class 2 The load is in between the effort and the fulcrum Wheelbarrow Class 3 The effort is in between the load and the fulcrum Tweezers

Linkages • A linkage can act as a lever. • In most cases it transfers one mechanical motion to another. • A linkage is often used to connect other mechanical devices such as cams to levers or to cranks – or vice versa. • A simple linkage will see a lever attached to a lever.

Types of linkages • Linkage fixed pivots • Linkage brings about change in direction and movement

Types of linkages • Linkage with several moveable parts • Components that can be used for pivots

Key terms • Lever – a rigid bar that can rotate around a fixed pivot called a fulcrum. • Linkage – a mechanism involving two or more levers. • Mechanism – creates movement. • Pivot – a point of rotation.

Task • Make the different types of linkage