Semi-universal torque coupling

A semi-universal torque coupling comprising an elongate axially rotatable female part with front and rear ends and a forwardly opening elongate polygonal socket opening entering its front end, the socket opening has a plurality of circumferentially spaced radially inwardly disposed longitudinally extending flats and a forwardly disposed bottom at its rear end;

• an elongate axially rotatable male part with inner and outer end portions and normally axially aligned with and extending forwardly from the female part, the inner end portion of the male part is a semi-spherical polygonal ball corresponding in cross-section with and slidable engaged in the socket opening in the female part in rotary driving and axial pivotal engagement therewith;
• and, an elongate coupling spring positioned centrally within the socket opening and normally concentric with the male and female parts, the spring being helically wound with closed convolutions so as to be axially non-compressible, axially yielding extendable and laterally yielding deflectable, the spring has a rear end fixedly connected with the female part at the bottom of the socket opening and a front end fixedly connected with the ball, the spring yieldingly maintains the female and male parts in axial alignment and in predetermined axial position relative to each other.