| CPC B23B 31/16 (2013.01) [B23B 25/00 (2013.01); B23B 31/2072 (2021.01); B23B 31/26 (2013.01); Y10T 279/17119 (2015.01)] | 1 Claim |
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1. A lathe comprising:
a spindle rotatable on a spindle axis and provided with a chuck having a closed state to hold a workpiece and an opened state to release the workpiece; and
a chuck operating apparatus which opens and closes the chuck, comprising:
a tilt claw provided outside the spindle and rotatable on the spindle axis, the claw having a first posture to bring the chuck into the opened state and a second posture to bring the chuck into the closed state;
a shifter provided outside the spindle and rotatable on the spindle axis, the shifter being movable in a direction of the spindle axis to be brought in a first position to bring the claw into the first posture and in a second position to bring the claw into the second posture; and
a driving unit having a shifter lever which moves the shifter in the direction of the spindle axis,
wherein an outward groove is entirely formed around an outer surface of the shifter with respect to the spindle axis to receive an insertion part of the shifter lever,
the insertion part of the shifter lever has a shifter bearing capable of being brought into contact with a side surface of the outward groove,
a roller is provided on the shifter in a contact position with the claw to roll in the direction of the spindle axis with a roller pin and a groove is formed on the claw to receive the roller when the chuck is in the opened state,
the roller has a first insertion hole through which the roller pin is passing in a direction of a rolling axis of the roller, and is rollable around the roller pin,
the shifter is provided with a plurality of holds, each of which is divided by a gap receiving the roller and has a second insertion hole through which the roller pin is removably passed to couple the roller to the shifter,
the driving unit is configured to drive the shifter lever to have the shifter bearing spaced apart from the side surface of the outward groove after moving the shifter in the direction of the spindle axis,
the claw includes a root having an insertion hole into which a claw pin is inserted,
the claw has a recess and a groove formed on the outer surface of the claw between the root and a movable end of the claw,
the recess and the groove are divided by a hill therebetween,
the groove is located between the recess and the movable end and is narrower than the recess,
the shifter is located within the recess and the groove in the first posture of the claw, and
at least a part of the shifter is located on the movable end of the claw in the second posture of the claw.
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