Mortising machine

Forming a mortise, a deep groove in a piece of wood which may form part of the joint with another piece, is a difficult job to carry out by hand, taking time, effort and good tools. Machines like this were developed to make the work easier. The chisel in this machine is controlled by vertical guides and is forced downwards by the action of the foot lever, the return being given by a helical spring. The wood to be morticed is held in a vice secured to the machine frame. By means of a screw thread in the top of the tool holder, it is made to rotate through one quarter of a circle in the last part of its ascent, and through another quarter in commencing its descent, so that is turns half round after each stroke.