Abstract: A detachable earmuff has an entrance separation which is normally biased closed and which is resiliently flexibly openable for receiving a headband of a headset for retaining the earmuff in covering relation to a users ear and an earphone held to the users ear by means of the headband. For biasing the entrance separation, overlapping parts of a frame structure extend inwardly from the outer end of the entrance separation. In one embodiment the earmuff frame may comprise a generally flat split plastic ring. In another embodiment the earmuff frame may comprise a resilient wireform which may be constructed in one piece.

Abstract: An open end one way torque wrench has a wrench head recess in which a pair of articulated jaw members is adapted to receive and apply torque to a multifaced element by turning the wrench in one direction, and the jaw members automatically release and move into engagement with the next succeeding faces of the element by swinging the wrench in the opposite direction. The wrench head has a substantially semicircular track on which one of the jaw members rides. The other jaw member rides a tangential extension of the track. The jaw assembly is normally biased toward a torquing shoulder from which the assembly retreats during the release and re-engagement action of the jaw assembly.