Abstract: Apparatus for applying force in one direction to an article and restraining movement of the article in the opposite direction. There is provided a reciprocally rotatable link and means to rotate the link connected to a first end of the link and a cam shaft having a first and second cylindrical portion, said first cylindrical portion having a different central axis of rotation than the second cylindrical portion. The first cylindrical portion of the cam shaft is secured to the end of the link opposite the end connected to the rotating means to provide rotational movement of the cam shaft when the link is rotated. A mounting block with a bore therethrough has the first cylindrical portion of the cam shaft passing through the bore. A rotating member pivotal at one end and movable from a first position to a second position has the second cylindrical portion of the cam shaft rotatably secured thereto at the end opposite from the pivotal end.