Hammer action

Usually in order to increase the force (among others) of  hand operated fixture a cam actuated (or wedge actuated) mechanism is used. In this way the produced forced is multiplied (depends on cam geometry). The main problem is a large produced friction force which reduces the efficiency during clamping. During unclamping action the clamping force produces a seal between the clamp post and the cam (or wedge) which is difficult to break (depends on clamping forces). The hand operated clamp source will be a linear or a rotational motion of a pusher-puller or a lever. An effective way to increase this force beyond that normally applied by hand is to incorporate a striking. The striking is a hammer action force to the clamp source. This hammer action is achieved by permitting the actuating part to move free from opposite forces (friction, clamping forces) for a small space (or rotate for a small angle). This space allows the production of a linear momentum (or angular) and the moment of impact (striking) increases the amount of applying force. This hammer action also helps breaking the friction seal of the clamping cam when the unit is unclamp. Breaking the seal requires smaller forces due to reverse effect of the clamping forces so sizing of the parts must consider clamping action. Due to hammer action the surfaces are under impact forces so hardened materials must be used for the striking parts. Hammer action is applicable with cam, wedge and some screw actuating fixtures.