Machine Parts

Clamp:    Clamp is a basic element of workholder.The action of pressing the workpiece against the locating surface and hold it against the forces acting upon it is known as clamping. Basic rules of applying clamping forces: Ø Clamping force should be directed towards the nest or locating surfaces. Ø They should be arranged in such a way that the thrust of cutting tool is at a required distance from the clamp. Ø Clamping forces are to be applied on the heavy and strengthy portion of the workpiece. Ø Clamping device should be designed in such a way that it would act for the specific and the correct work.   The above discussed points of rules of applying the clamping forces should be maintained mandatorily otherwise workpiece on which operation to be performed may collapse.

                                                          The additional considerations applied to the lathe fixtures are given below: 1. Clamps and other holding devices should be designed in such a way that they will not be loosened by centrifugal force. 2. The workpiece should be gripped on its largest diameter,and whenever possible the gripping diameter should be larger than the diameter being machined. 3. The fixture should be well balanced.Irregular –shaped workpieces may have to be counter weighted to prevent vibration .It is not necessary to achieve perfect balance unless the workpiece is rotating at high speeds. 4. The fixtures should be as lightweight as possible since it is rotating. 5. projections and sharp corners should be avoided as the operator may not be able to see them while the tool is rotating. 6. Thin sections of the workpiece may require support to resist the pressure of the lathe tool