Abstract: A drilling mechanism for drilling one or more holes in a workpiece includes a collet for securing the drilling mechanism to a hole formed in a fixture mounted in front of the workpiece. The collet is slidable rearwardly along a tapered nosepiece to be elastically expanded outwardly into tight frictional contact with the fixture hole. The collet comprises a clamping part and a separate displacement part connected thereto. A contact interface is formed by the clamping and displacement parts for transmitting rearward forces from the displacement part to the clamping part. The contact interface extends for 360 degrees about the center axis of the collet. Longitudinal play is provided between the displacement and clamping parts so that when the collet is to be moved forwardly and released from the fixture, the displacement part is initially moved longitudinally relative to the clamping part to apply a radially inward force to the clamping part for disengaging the clamping part from the fixture hole.

Abstract: A nut drive adapter for use with a power tool includes a splined driven end located coaxially with a square drive. Changing the size of the square drive used with power tools requires only changing the nut drive adapter rather than changing the entire drive housing.

Abstract: A speed limiter for setting the speed of an air tool has a flow passage body which screws into the air inlet of the tool. The body defines an axial air flow path therethrough with an annular land adjacent to internal threads. An adjusting insert is threaded to the internal threads and has a pair of opposed axially extending grooves formed in its periphery which extend further radially inward than the land. The size of the air flow passage and therefore the speed of the tool is varied by adjusting the insert toward or away from the land.