InventorsToolbox: The Elements of Machines. Simple Machines: These devices were all in common use for centuries before Leonardo's time. Each one makes work easier to do by providing some trade-off between the force applied and the distance over which the force is applied. Wheel and Axle In this machine a wheel or spoke is locked to a central axle so that when one is turned the other must turn. A longer motion at the edge of the wheel is converted to a shorter more powerful motion at the axle. In reverse, a short powerful force at the axle will move the wheel's edge a greater distance.
Pulley System A single pulley simply reverses the direction of a force. Wedge A wedge converts motion in one direction into a splitting motion that acts at right angles to the blade. Screw A screw is a central core with a thread or groove wrapped around it to form a helix. Lever A lever is a stiff rod that rotates around a pivot point. Gears Gears are toothed or pegged wheels meshed together to transmit motion and force. For YOUR KIDS! Simple Machines Activities. Dirtmeister: Simple Machines -- Investigate the Facts. "inQuiry Almanack" - Spotlighting... - March, 1997.
Simple Machines Made Simple.