Gripper plate construction for cartridge dispensing guns, with plates having circular holes with angled portions to limit penetration into and reduce scoring marks on rod

摘要

A cartridge dispensing gun comprises a pusher mechanism for incrementally displacing a dispensing piston of the cartridge, said pusher mechanism comprising a pusher rod (4) incrementally advanced by actuation of a trigger to tilt and displace a gripper associated with the rod. The gripper is formed by two or more gripper plates (16) mounted in parallel, and each having a passage through which the rod passes. The passage in the gripper plate is bounded at one side of the gripper plate by an arc of part-circular shape to define a part-circular edge which grips the rod when the gripper plate is tilted upon actuation of the trigger and also by a surface which is inclined to the axis of the passage and which contacts the surface of the rod when the gripper plate is tilted to thereby restrict the extent to which the edge can penetrate into the rod and cause damaging scoring of the rod. Such gripper plate construction per se is also claimed