Piston joint

摘要

A joint for positioning between first and second elements includes an outer member and an inner member. The first and second elements are arranged for linear motion along a common axis. The outer member is configured for movement relative to the first and second elements along a first axis perpendicular to the common axis, and the inner member is mounted within the outer member for rotation relative to the outer member about a second axis perpendicular to the first axis and the common axis and for movement relative to the outer member along the second axis. The outer member is restrained from movement along the second axis. The outer member defines first and second parallel flat sides. Each flat side defines a plane perpendicular to the common axis. The outer and inner members each defining an opening for receiving a drive arm.