An indexing apparatus for a rotary table has a support shaft rotatably supported by a base member in which indexed terminal positions of the rotary table is determined by abutment of a stopper member provided on the rotary table against positioning members provided on the base member. The indexing apparatus comprises a rack-pinion mechanism comprising a rack and a pinion fixed around the support shaft of the rotary table for rotating the same, a feed screw shaft rotatably supported by the base member and extending along the rack in a direction of the movement thereof, a breakable electric motor for driving the feed screw shaft, and a feed nut engaging the feed screw shaft. The rack and the feed nut are arranged so that either one of them has integral portions disposed at both sides of the other with spaces left on both the sides in the direction of the movement of the rack. Annular springs are disposed in each space. As the rotary indexing operation approaches the terminal position, the spring is elastically deformed in the direction of the movement of the rack so that shocks due to the abutting are prevented. Immediately before the indexed terminal positions, the speed of the motor is reduced and then the motor is braked.
A work pallet that is arranged to be simple in construction capable of machining five faces of a work by rotating it around the axis of rotation. A work pallet (4) comprises a base body (5) detachably fixed to the table (3) of a machine-tool (1), a pallet main body (6) fixed on the top face of this base body (5), and a work setting face forming body (7), provided on this pallet main body (6) in a way to turn around the rotational axis (20) and having a work setting face (21a) for fixing a work (2), and the pallet main body (6) is provided with a clamping mechanism (31) for releasably fixing the work setting face forming body (7), and a rotational driving mechanism (32) for rotationally driving the work setting face forming body (7) around the rotational axis (20). When machining the work (2), the work setting face forming body (7) can be rotated around the rotational axis (20) by the rotational driving mechanism (32), and the work setting face forming body (7) can be fixed to the pallet body (6) with the clamping mechanism (31) in order to machine five faces of the work (2).
A positioning system for controlling the rotation of a shaft or other member through a defined angular increment. The system includes a rotor which may be coupled in torque transmitting communication with the shaft, and a an indexing assembly for driving the rotor. The indexing assembly includes a slide or other follower which is operably coupled to a first actuator, which may be hydraulically or other otherwise fluid-powered, and to a biasing member, which may be a second actuator, which is also operably coupled to the first actuator. The first actuator is actuable to move the follower and, in turn, a pawl from a locking position to a release position, and to engage another pawl with the rotor effecting the rotation thereof in a rotary direction through the angular increment. The first actuator is de-actuable to return, responsive to the biasing member, the pawls and follower to their original positions.
Method and system are provided for controllably driving a rotary drive of a rotary index table assembly utilizing a PLC which receives various sensor signals including a feedback signal from a resolver to generate a reference central signal which, in turn, is used by a positioning drive including an electric servomotor to drive the rotary drive. The positioning drive includes a servoamplifier and a microprocessor for generating commands for controlling the servoamplifier in response to the reference central signal. The PLC also controls a hydraulic control unit which controls the axial position of the index table relative to a base of the assembly.
