| 摘要 |
In a fastener driving tool having a fastener holding nosepiece comprised of three concentric sleeves, the middle one of which is axially movable to carry a circumferential array of radially shiftable balls to and from inwardly cammed engagement against cam surfaces in the outer sleeve to grip the fastener head against the inner sleeve and release the head, improved structure wherein (1) the inner and outer sleeves have portions axially displaced from the middle sleeve which are threadedly connected to adjust the axial distance between the cam surfaces and inner sleeve for accommodating fastener heads of different axial thicknesses and radial tolerances; (2) to facilitate interchangeability of nosepieces, the inner sleeve is axially slidably retained on an adapter sleeve against a spring bias by a pin and slot connection with inner and adapter sleeves having means cooperable upon relative turning thereof to withdraw the pin from the slot and the pin being movable inwardly into engagement with a retaining ring to retain the spring in the adapter sleeve when the inner sleeve is removed therefrom; (3) the nosepiece is optionally provided with an adapter adapted to be mounted on the fastener driver of the tool rather than the tool body; and (4) where the tool is air driven, ducting is provided to introduce exhaust air from the tool into the sleeves for blowing foreign matter out of the nosepiece. |
