Abstract: A drill bit or other working tool is provided with driven end segments which are removably received in longitudinal slots formed in a shank. The slots bottoms are contacted by the driven end segments to align the working tool with the shank; and, slot side walls contact the driven end segments for transmission of torque to the working tool. The working tool and shank are formed separately, then connected together, and the shank is connected to and driven by a rotary device.

Abstract: Sliding closures such as sliding glass doors or windows are locked by a stop member mounted in the upper track for the closures. The stop member is elongated longitudinally of the track and is pivoted about a transverse horizontal axis to permit its movement between an upper retracted position and a lower door-abutting position. The principal improvements comprise: (a) a stationary shoulder which abuts a part of the stop member when in its door-abutting position to resist excessive forces applied against the stop member by sliding movement of the door; (b) stationary pivotal supports for the stop member connected on both sides thereof to the track; and, (c) the supplemental use of a lateral projection attached to an outer sliding door for abutment by the stop member. Further, there is provided a novel spacer assembly in the upper track to limit upward movement of the door.