Link motion is a general category that includes a variety of modified slide motions. It must be understood that a single modified slide motion is not the ideal for performing all types of stamping operations.
Conventional mechanical presses have long been equipped with a crankshaft or eccentric gear drive where the slide velocity was symmetrical between the bottom and top halves of the press stroke. With this simple system, press working was limited to those operations where the crank motion slide velocity would produce an acceptable part. However, the need for improved plastic flow of metal during a stamping operation often cannot be achieved by use of a standard crank motion press because of the excessive slide velocity through the working portion of the press stroke. To meet the requirement for improved metal flow, modern press builders have designed drive modifications that alter the slide motion as the press goes through the working portion of the stroke. The modified slide motions improve stamping operations such as deep drawing, forming, coining, embossing, flow control forming, cold forging, blanking and conventional progressive or transfer die operations.