Actuator for workpiece holding device
A power chucking system 10 comprises a chuck mounted on a headstock, the chuck with its jaws being caused to rotate by rotation or the machine spindle 6 . The spindle 6 may be engaged with the pulley 1 in order to rotate a work piece retained within the chuck jaws. A clutch 2 may be used to disengage the spindle 6 from the pulley 1 and to lock the spindle 6 to the head stock. In this configuration, rotation of the pulley 1 will cause an actuator jack 7 to screw or unscrew, into or out of spindle 6 , in order to open or close the chuck jaws to grip release the workpiece.
1. A chucking system, comprising a chuck with jaws for holding a work piece, the chuck being mounted on a spindle for rotation therewith by means of the machine drive, chuck actuator means for moving the jaws to grin or release the work piece, transmission means whereby the machine drive is normally coupled to the spindle to cause rotation thereof, a coupling which is normally biased into engagement with the transmission means whereby the machine drive is transmitted, through the coupling, to the spindle and means for selectively uncoupling said transmission means from the spindle such that rotation of the uncoupled transmission means relative to the spindle drives the chuck actuator means, and in which the coupling includes a clutch.
2. A system according to claim 1 in which the clutch comprises a dog clutch.
3. A chucking system, comprising a chuck with jaws for holding a work piece. the chuck being mounted on a spindle for rotation therewith by means of the machine drive, chuck actuator means for moving the jaws to grip or release the work piece, transmission means whereby the machine drive is normally coupled to the spindle to cause rotation thereof, a coupling which is normally biased into engagement with the transmission means whereby the machine drive is transmitted, through the coupling, to the spindle and means for selectively uncoupling said transmission means from the spindle such that rotation of the uncoupled transmission means relative to the spindle drives the chuck actuator means, and in which the coupling includes a clutch, and in which the coupling is disposed for lateral movement between a first position in which a first surface of the clutch engages with a plate fixed to a headstock, thereby unlocking the transmission means from the spindle whilst at the same time locking it to the headstock, and a second position in which a second surface of the coupling engages with an attachment fixed to the spindle, thereby locking the transmission means to the spindle whilst at the same time unlocking it from the headstock.