| 摘要 |
1329975 Chucks ROBERT BOSCH GmbH 5 June 1970 [7 June 1969] 27137/70 Heading B3B A drill chuck comprises a cylindrical body 1, a housing 10 and at least two jaws 18 which are spring supported against an interior conical surface of the housing and biased axially upwardly against a clamping plate 7 axially fixed to the body 1 and having a surface perpendicular to the chuck axis, axial movement of the housing 10 on the body altering the position of the jaws to grip a drill, characterized in that the housing 10 is axially movable when in a predetermined rotational position to provide a coarse adjustment for opening and closing the jaws, and at least part of the housing is rotationally displaceable on the body to adjust a clamping thread means to tighten and slacken the jaws. In the embodiment of Fig. 1 an end portion 4 of the body is threaded to engage the threaded radially inner ends of a pair of projections 13 of the housing, and is also provided with two longitudinal slots with which the projections 13 can be aligned to allow the coarse adjustment. The jaws are tightened slightly less than one half a revolution of the housing. The housing may be rotated by a bevel gear key. In a further embodiment (Figs. 3, 3a, 4, not shown) the housing is in two parts threaded together, a lower part being rotated to tighten the jaws. The upper half includes spring-biased pins that engage a series of steps formed in a wedge shaped cut-out in the body. In an alternative arrangement (Figs. 5 and 6, not shown) coarse adjustment is provided by balls engaging sloping ramps formed in the body, and annular grooves formed in an upper part of the housing grip the said part to the body to allow a lower part to be rotated to effect the clamping means to be tightened. The body 1 is fixed to a spindle by a threaded bore 2a. |
