摘要 |
A lathe chuck has a chuck body centered on and rotatable about a main axis and formed with a plurality of radially extending jaw-guide grooves and, transverse to the grooves, with respective guide passages each in turn formed with an abutment. Respective jaws displaceable in the grooves each have at least one tooth exposed in the respective guide passage and respective control rods displaceable along the passages each have at least one tooth meshing with the tooth of the respective jaw. A control pin is axially displaceable in each rod between an extended position projecting into the respective jaw-guide groove and a retracted position. The control pins are displaced on engagement with the teeth of the respective jaws into the retracted positions. A latch pin is axially displaceable in each rod between an extended latching position engaging the respective abutment and preventing movement of the respective rod in the respective passage and a retracted position permitting such movement. A spring urges the pins into their extended positions, and a coupling member engaged between the pins displaces the respective latch pin into the respective retracted position on displacement of the control pin into its retracted position. Thus, when there is no jaw in the guide groove, the latch pin of the respective control rod latches same against movement in the respective passage.
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