Patent ID: 7426966

Claim:
An apparatus for converting backward and forward oscillations of an oscillating member into relative movement of the member along a rail, comprising a housing securable to an oscillating member and guided for movement relative to a rail, the housing providing a first fulcrum and a first biasing means spaced apart along the length of a lever, the lever having a rail engaging formation spaced along its length from the first fulcrum, the first biasing means resiliently biasing the lever about the first fulcrum for the engaging formation to grip the rail resisting movement in a backward direction, the resilient bias of the first biasing means selected to be overcome for the engaging formation to release the rail for movement in a forward direction and the first fulcrum providing a second biasing means that resiliently biases the lever about a second fulcrum provided by the housing for movement in the backward direction, wherein the first biasing means and the second biasing means are piston and cylinder assemblies with the pistons contacting the lever.