Clutch for power tool

Patent metadata

Field	Value
Publication number	US-9494200-B2
Application number	US-201313828149-A
Country	US
Kind code	B2
Filing date	Mar 14, 2013
Priority date	Mar 14, 2013
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

A clutch for a power tool includes an adjustment ring configured to move axially relative to the housing while being rotated relative to the housing. A spring retainer is disposed axially rearward of the adjustment ring. The spring retainer is coupled for rotation together with the adjustment ring and configured to remain substantially axially stationary relative to the housing when rotated. A spring is disposed between the adjustment ring and the spring retainer. A clutch face is coupled to a portion of the transmission. A locking member is disposed between the spring retainer and the clutch face. The locking member is configured to transfer a holding force exerted by the spring to the clutch face. Rotation and axial movement of the adjustment ring alters the holding force exerted by the spring. When an amount of output torque exceeds the holding force, torque transmission to the output spindle is effectively interrupted.

First claim

What is claimed is:

1. A power tool comprising:
a housing;
a motor disposed in the housing;
an output spindle received at least partially in the housing;
a transmission disposed in the housing and configured to selectively transmit torque from the motor to the output spindle;
a clutch assembly disposed between the transmission and the output spindle, the clutch assembly including
a clutch adjustment ring configured to move axially relative to the housing while being rotated relative to the housing,
a spring retainer disposed axially rearward of the clutch adjustment ring, the spring retainer coupled for rotation together with the clutch adjustment ring and configured to remain substantially axially stationary relative to the housing when rotated;
a spring disposed between the clutch adjustment ring and the spring retainer;
a clutch face coupled to a portion of the transmission;
a locking member disposed between the spring retainer and the clutch face, the locking member configured to transfer a holding force exerted by the spring to the clutch face,
wherein rotation and axial movement of the clutch adjustment ring alters the holding force of the spring to select a clutch setting among a plurality of different clutch settings such that, for each clutch setting, when an output torque exceeds the holding force, torque transmission from the transmission to the output shaft is effectively interrupted.

2. The power tool of claim 1 , wherein the clutch assembly further comprises a clutch housing having rearward base portion configured to receive the clutch face, and a nose portion configured to receive at least a portion of the output spindle.

3. The power tool of claim 2 , wherein the nose portion includes an externally threaded portion, and the clutch adjustment ring is internally threaded over the externally threaded portion.

4. The power tool of claim 3 , wherein the spring retainer is internally unthreaded and received over the nose portion.

5. The power tool of claim 1 , further comprising a clutch adjustment sleeve non-rotatably coupled to the clutch adjustment ring to the spring retainer, such that rotation of the clutch adjustment sleeve causes rotation of the clutch adjustment ring and the spring retainer.

6. The power tool of claim 1 , wherein the clutch adjustment ring has a first recess that receives a first end of the spring and the spring retainer has a second recess that receives a second end of the spring.

7. The power tool of claim 1 , wherein the spring comprises one of a compression spring and a wave spring.

8. The power tool of claim 1 , wherein the clutch assembly further comprises a clutch plate disposed between the spring retainer and the locking member, the clutch plate transferring the holding force from the spring retainer to the locking member.

9. The power tool of claim 1 , wherein the locking member comprises at least one of a ball and a pin, the clutch face comprises a ramped surface, and torque transmission from the transmission to the output shaft is effectively interrupted when the output torque causes the locking member rides over the ramped surface.

10. The power tool of claim 1 , wherein the transmission comprises a planetary gear set having at least one ring gear and the clutch face is connected to the at least one ring gear, such that torque transmission is effectively interrupted when the ring gear is permitted to rotate relative to the housing.

11. A clutch assembly for a power tool having a housing, a transmission and an output spindle, the clutch assembly comprising:
a clutch adjustment ring configured to move axially relative to the housing while being rotated relative to the housing;
a spring retainer disposed axially rearward of the clutch adjustment ring, the spring retainer coupled for rotation together with the clutch adjustment ring and configured to remain substantially axially stationary relative to the housing when rotated;
a spring disposed between the clutch adjustment ring and the spring retainer;
a clutch face coupled to a portion of the transmission;
a locking member disposed between the spring retainer and the clutch face, the locking member configured to transfer a holding force exerted by the spring to the clutch face,
wherein rotation and axial movement of the clutch adjustment ring alters the holding force exerted by the spring to select a clutch setting among a plurality of different clutch settings such that, for each clutch setting, when an amount of output torque exceeds the holding force, torque transmission from the transmission to the output shaft is effectively interrupted.

12. The clutch assembly of claim 11 , further comprising a clutch housing that includes a rearward base portion configured to receive the clutch face, and a nose portion configured to receive at least a portion of the output spindle.

13. The clutch assembly of claim 12 , wherein the nose portion has an externally threaded portion, and the clutch adjustment ring is internally threaded over the externally threaded portion.

14. The clutch assembly of claim 13 , wherein the spring retainer is internally unthreaded and received over the nose portion.

15. The clutch assembly of claim 11 , further comprising a clutch adjustment sleeve non-rotatably coupled to the clutch adjustment ring and to the spring retainer, such that rotation of the clutch adjustment sleeve causes rotation of the clutch adjustment ring and the spring retainer.

16. The clutch assembly of claim 11 wherein the clutch adjustment ring has a first recess that receives a first end of the spring, and the spring retainer has a second recess that receives a second end of the spring.

17. The clutch assembly of claim 11 , wherein the spring comprises one of a compression spring and a wave spring.

18. The clutch assembly of claim 11 , further comprising a clutch plate disposed between the spring retainer and the locking member, the clutch plate transferring the holding force from the spring retainer to the locking member.

19. The clutch assembly of claim 11 , wherein the locking member comprises at least one of a ball and a pin, and the clutch face comprises a ramped surface, wherein the locking member comprises at least one of a ball and a pin, the clutch face comprises a ramped surface, and torque transmission from the transmission to the output shaft is effectively interrupted when the output torque causes the locking member rides over the ramped surface.

20. A power tool comprising:
a housing;
a motor disposed in the housing;
an output spindle received at least partially in the housing;
a planetary gear transmission disposed in the housing and configured to selectively transmit torque from the motor to the output spindle, the planetary gear transmission having;
an input sun gear,
a planet gear meshed with the input sun gear,
an output carrier carrying the planet gear and configured to transmit output torque to the output spindle when the output carrier rotates, and
a ring gear meshed with the planet gear, and

a clutch assembly disposed between the planetary gear transmission and the output spindle, the clutch assembly including:
a clutch housing having a rearward base portion, and a nose portion having an externally threaded portion,
an internally threaded clutch adjustment ring received over the externally threaded portion of the clutch housing and configured to move axially relative to the clutch housing when being rotated relative to the clutch housing,
a non-internally threaded spring retaine

Assignees

• Black & Decker Inc

Inventors

• Kelleher Joseph P
• Krout Daniel L
• Tomayko David C

Classifications

• B25F5/001 Primary

  Gearings, speed selectors, clutches or the like specially adapted for rotary tools · CPC title

• B23B45/008

  Gear boxes, clutches, bearings, feeding mechanisms or like equipment · CPC title

• B25B23/141

  Mechanical overload release couplings · CPC title

• F16D7/00 Primary

  Slip couplings, e.g. slipping on overload, for absorbing shock (combined with yielding shaft couplings F16D3/14; fluid slip couplings F16D31/00 - F16D35/00) · CPC title

• B25D2250/165

  Overload clutches, torque limiters · CPC title