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Torque control and fluid shutoff mechanism for a fluid operated tool

  • US 4,576,270 A
  • Filed: 02/28/1983
  • Issued: 03/18/1986
  • Est. Priority Date: 02/28/1983
  • Status: Expired due to Fees
First Claim
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1. In a fluid power tool of the type including a fluid driven motor with a rotary output shaft, a fluid inlet to the motor, an inlet control mechanism to control fluid flow to the motor, and a clutch mechanism, connecting the output shaft with a tool bit, the improvement comprising, in combination:

  • a fluid shutoff mechanism associated with the clutch mechanism, said fluid shutoff mechanism including a throughbore axially extending through the shaft;

    a throttle rod in the throughbore translatable in one axial direction to terminate fluid flow through the fluid inlet to the motor and in the opposite axial direction to allow fluid flow to the motor;

    a passage in the shaft transverse to the throughbore intermediate the ends of the throughbore and adjacent an end of the throttle rod positioned in the throughbore;

    at least one radially displaceable member positioned in the transverse passage for engagement with the throttle rod;

    a slidable kickout sleeve on the shaft for retaining the radially displaceable member positioned in the passage for engaging the throttle rod;

    means biasing the slidable kickout sleeve to the position for retaining the radially displaceable member to engage the throttle rod;

    a thrust pin coaxial with the throttle rod and in the throughbore on the opposite side of the transverse passage from the throttle rod, said thrust pin engageable with the tool bit and translatable against the radially displaceable member to drive the throttle rod to open fluid flow through the fluid inlet; and

    a torque responsive sleeve release mechanism on the shaft slidable axially to release the slidable kickout sleeve from retaining the radially displaceable member, said radially displaceable member movable in the passage to permit axial translation of the throttle rod to terminate fluid flow to the fluid inlet, said sleeve release mechanism including a tool bit holder mounted on the shaft and rotatable with respect thereto, and a cam sleeve slidably mounted on the shaft for axial movement, said cam sleeve biased for engagement with a cam surface on the tool bit holder whereby during normal operation of the tool, the tool bit holder remains fixed relative to the cam sleeve, said tool bit holder rotating relative to said cam sleeve to axially drive the cam sleeve when a threshold torque acts on the tool bit holder.

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