| 摘要 |
1308741 Tool turrets; indexing INDEX-WERKE KG HAHN & TESSKY 19 April 1971 [3 March 1971] 26628/71 Headings B3B and B3T An indexible tool turret 1, e.g. for a turret lathe is provided with locking teeth 41 and is axially movable to engage and disengage the teeth 41 and to allow a drive mechanism to rotate the turret when in the disengaged position to a predetermined working position, whereupon the turret may be retracted and finally clamped tightly in its indexed position. The drive mechanism is arranged to perform the final stage of the indexing movement at reduced speed. The turret spindle 20 carries a member 40 which forms part of a claw clutch 38 which is disengaged when the turret is clamped in its working position, i.e. when axially retracted but alternatively (when the turret is axially advanced) forms a drive connection to the turret from a worm and worm-wheel drive 26, 44. The turret is biased by springs 35 towards the unlocked position and axial movement thereof is basically caused by the co-operation of cam faces on claws 32, 33, the latter being fixed and the former arranged on the front face of a rotatable nut member 30. Rotation of the nut 30 also serves to apply a clamping force to the turret when the locking teeth 41 are engaged by reason of the threaded engagement of the nut with a threaded bush 48 mounted on the spindle 20. A control drum 39 integral with the worm-wheel 44 carries a series of cams engageable with switches 45 and an end position indicating plunger 42 co-operates with a switch 43 the switches being suitably arranged for numerical control of the machine tool to ensure that the turret rotates in the shortest direction to and is stopped at a required working position. A rotary hydraulic control valve 46 carried at the end of the shaft 20 is brought into operation by the electrohydraulic control circuitry only as the required working position is approached to check the speed of an hydraulic motor driving the indexing mechanism, intermediate positions of the turret being passed without any reduction in speed. |
