Positive feed tool with a slip clutch and a method, to prevent jamming

摘要

Positive feed tools and methods of use that include a spindle with a distal end configured to receive a tool bit. The spindle is movable in a forward direction for the tool bit to act on a workpiece, and a retract direction to move the tool bit away from the workpiece. The spindle is configured to retract to a home position at which an air motor that drives the spindle is shut off. The feed tool includes a clutch to prevent jamming of the spindle at the home position in the event the air motor is not shut off at the proper time.

主权项

1. A positive feed tool configured to operate in a forward direction and a reverse direction, the feed tool comprising:
an elongated spindle aligned with and configured to axially move along a feed path, the spindle including a retract stop to control an extent of axial movement of the spindle in the reverse direction; a spindle rotation mechanism coupled to the spindle to rotate the spindle; a spindle feed gear and a differential feed gear configured to drive the spindle axially along the feed path, the spindle feed gear and the differential feed gear each including gear teeth that are engaged together; a clutch mechanism positioned at the differential feed gear to selectively control rotation of the differential feed gear, the clutch mechanism including a contact member and a biasing member; wherein the clutch mechanism being configured to engage with the differential feed gear to:
prevent rotation of the differential feed gear and the spindle feed gear causing the spindle to move in the reverse direction when the torque that is applied to the differential feed gear through the spindle feed gear is less than a holding force applied to the contact member;allow rotation of the differential feed gear and the spindle feed gear to prevent the spindle from moving further in the reverse direction when the torque that is applied to the differential feed gear through the spindle feed gear is greater than the force applied to the contact member.