Linear ratchet apparatus

A linear ratchet apparatus has a toothed rack mounted for linear movement along an axis defining a forward direction and a reverse direction. A number of latches mutually spaced at intervals in a direction parallel to the axis are mounted for linear reciprocation perpendicular to the axis and are forcibly biased into contact with the teeth of the rack. The mating surfaces of the teeth and latches are shaped such that in normal operation, the latches override the teeth allowing the rack to be moved in the forward direction. Shear engagement between at least one of the latches and at least one of the teeth limits reverse travel of the rack to not more than a predetermined maximum backlash distance which can be specified as desired based on the number and spacing of the latches and the width of the teeth of the rack. A release member coupled to the latches can be actuated to enable reverse movement of the rack.