Mechanical Toys!What are Mechanical Toys?
They use a series of Mechanisms, such as Cams, Bell Cranks, Levers and Pulleys to make a small object, such as a model man, animal or vehicle, move and perform.Mechanical toys are powered by mechanical energy, for example using rubber bands, springs, flywheels, candles or gravity.
In the examples above, the off centre wooden wheel creates an eccentric movement which causes the lever resting on it (the follower) to rise up and down.The off centre card wheels are used as cams. As the followers which are resting on them are mounted on one side rotation is achieved as well as up and down movement. The card figures are mounted on the dowel axles by paper straws and can be replaced easily with other figures.
Mechanisms are devices that have been designed to make jobs easier. They all have certain things in common:
They involve some kind of motion. They involve some kind of force. They must have some kind of input to make them work. They produce some kind of output.
What are CAMS?
Cams is part of a machine used to provide a repetitive straight-line or back-and-forth motion to a second part, known as the follower. They are used to open and close the inlet and exhaust valves of an automotive engine, to index parts of automatic machinery for mass production, to operate a sequence of control switches in electrical equipment, and in many other machines. Complex cam shapes may be required to produce a desired motion.
The Three type of cams and their common uses...
The most common is the disk cam.The cam profile here is cut from a disk mounted on a rotating shaft. The follower can be a flat plate moving vertically in a straight line, or it can be a roller or knife-edge that moves in a straight line or is pivoted. The follower is usually spring loaded to retain contact with the cam.
The second type of cam commonly used is the cylinder cam. The follower in which is a pivoted roller moving along a groove cut into a cylindrical cam rotor.
The third type is the translation cam in which the required profile that defines the motion is cut into a flat plate that moves back and forth. The follower is a spring-loaded knife edge that moves up and down. It can be observed from the figures that the motion of the follower can be changed easily, in order to obtain a desired sequence, by altering the shape of the cam profile.
