| 摘要 |
1309989 Hollow spindle chucks PAUL FORKARDT KG 19 April 1971 [19 Feb 1970] 21400/71 Headings B3B and B3T A machine tool chucking device comprises a chuck at one end of a hollow spindle through which a chuck operator extends to a rotary vane actuator at the other end of the spindle, radially movable interchangeable jaws operable by tangentially movable slide members having teeth meshing with a pinion on the chuck operator, and a control mechanism which prevents drive being applied to the spindle when the angular position of the rotary vane actuator corresponds to a radial positioning of the jaws at which they are disengaged from their slide members. In the embodiment shown the chuck 2 has radially movable jaws 5 comprising master jaws 5a having teeth 5c meshing with teeth 6b on tangentially movable slide blocks 6. The latter are moved by rack-and-pinion mechanism 6a, 7, the pinion 7 being secured for rotation with a torque tube 8 extending through spindle 1. The tube 8 is connected at the rear end of the spindle with a torque actuator 3 comprising cylinder 11 housing a rotary vane assembly 12 to which tube 8 is secured. An extension spindle 13 of the assembly 12 is encompassed by a fixed housing 14 through which fluid-either pneumatic or hydraulic-to operate the actuator 3 passes. The jaws 5 are associated with the slide blocks 6 in such a way that they disengage from each other at a preset radial position, thus allowing jaw replacement &c. In order to prevent drive from being transmitted to the spindle 1 while the jaws are free of the slide blocks 6, a control mechanism responsive to the angular position of the vane assembly 12, and hence slide blocks 6, is provided. The mechanism incorporates an axially movable pin (17), (Fig. 4, not shown), in the extension spindle 13, which moves when operating pins (19) are moved radially by their co-operation with cam-tracks formed at appropriate angular locations on a flange ring 15. Pin (17) pushes a switch-operating member 21. In another embodiment (Figs. 7 and 8, not shown), an axially movable pin (17a) is apertured to receive an operating pin (19) which bears on axially-profiled cam tracks on a flange ring (15a). In a further embodiment (Fig. 9, not shown), the extension spindle (13a) is hollow and mounts a disc (17c) which moves axially to operate switch member (22a) when pins (17b) ride on cam-tracks formed on a ring (15b). In other embodiments (not shown) the control switch can be inductively, capacitively, optically, or magnetically operated. |
