Clutch mechanism for rotary power tool

Patent metadata

Field	Value
Publication number	US-12540645-B2
Application number	US-202418435430-A
Country	US
Kind code	B2
Filing date	Feb 7, 2024
Priority date	Nov 4, 2016
Publication date	Feb 3, 2026
Grant date	Feb 3, 2026

Abstract

A clutch mechanism is used in a rotary power tool having a motor. The clutch mechanism includes an input member to which torque from the motor is transferred and an output member co-rotatable with the input member. The output member defines a rotational axis. A cam surface is formed on one of the input member or the output member. First and second compression springs are carried by the other of the input member or the output member for co-rotation therewith. A follower has a circular cross-sectional shape and is biased against the cam surface by the first and second compression springs. In response to relative rotation between the input member and the output member, the cam surface displaces the follower along a line of action coaxial or parallel with each of the first and second compression springs. The line of action does not intersect the rotational axis.

First claim

What is claimed is:

1 . A clutch mechanism for use in a rotary power tool having a motor, the clutch mechanism comprising:
an input member to which torque from the motor is transferred; an output member co-rotatable with the input member, the output member defining a rotational axis; a cam surface formed on one of the input member or the output member; first and second compression springs carried by the other of the input member or the output member for co-rotation therewith; and a follower having a circular cross-sectional shape, the follower biased against the cam surface by the first and second compression springs, wherein, in response to relative rotation between the input member and the output member, the cam surface displaces the follower along a line of action coaxial or parallel with each of the first and second compression springs, and wherein the line of action does not intersect the rotational axis.

2 . The clutch mechanism of claim 1 , wherein when the motor transfers torque to the input member and when the first and second compression springs bias the follower against the cam surface, the output member co-rotates with the input member.

3 . The clutch mechanism of claim 1 , wherein the follower includes a protruding portion with a circular cross-sectional shape having a diameter that is smaller than a diameter of the circular cross-sectional shape of the follower.

4 . The clutch mechanism of claim 3 , wherein one of the input member or the output member defines a slot that defines a longitudinal axis that is parallel to the line of action, and wherein the protruding portion is received within the slot.

5 . The clutch mechanism of claim 1 , wherein the member that carries the first and second compression springs defines a pocket in which the first and second compression springs are received, the pocket being oriented transverse to the rotational axis, such that the line of action is transverse to the rotational axis.

6 . The clutch mechanism of claim 5 , further comprising a separator within the pocket and between the first and second compression springs.

7 . The clutch mechanism of claim 6 , wherein the separator is a sheet of metal.

8 . The clutch mechanism of claim 5 , wherein each of the first and second compression springs has a first end abutted against a base of the pocket and a second end that is opposite the first end and that protrudes from an opening of the pocket.

9 . The clutch mechanism of claim 8 , wherein the second end of each of the first and second compression springs engages the follower to bias the follower against the cam surface.

10 . A rotary power tool comprising:
a motor; an output shaft; and a clutch mechanism positioned between the motor and the output shaft to transfer torque from the motor to the output shaft, the clutch mechanism including
an input member to which torque from the motor is transferred,
an output member arranged within and co-rotatable with the input member, the output member defining a rotational axis,
a cam surface formed on one of the input member or the output member,
a compression spring carried by the other of the input member or the output member for co-rotation therewith, and
a follower having a circular cross-sectional shape biased against the cam surface by the compression spring,
wherein, in response to relative rotation between the input member and the output member, the cam surface displaces the follower along a line of action coaxial or parallel with the spring, and wherein the line of action does not intersect the rotational axis.

11 . The rotary power tool of claim 10 , wherein the input member is an outer ring having outer teeth.

12 . The rotary power tool of claim 11 , wherein the motor includes an output shaft having a pinion gear that is meshed with the outer teeth of the outer ring.

13 . The rotary power tool of claim 11 , further comprising a transmission for transmitting torque from the output member to the output shaft, wherein the transmission includes an intermediate shaft coupled for co-rotation with the output member.

14 . The rotary power tool of claim 13 , wherein the output member includes a hub defining an aperture therethrough, and wherein the intermediate shaft has a cross-sectional shape that corresponds to a cross-sectional shape of the aperture.

15 . A clutch mechanism for use in a rotary power tool having a motor, the clutch mechanism comprising:
an input member to which torque from the motor is transferred; an output member co-rotatable with the input member, the output member defining a rotational axis; a cam surface formed on one of the input member or the output member; a pocket formed on the other of the input member or the output member for co-rotation therewith, the pocket defining a longitudinal axis that is transverse to the rotational axis; a compression spring received by the pocket for co-rotation therewith, the compression spring defining a longitudinal axis that is co-axial or parallel with the longitudinal axis of the pocket; and a follower having a circular cross-sectional shape biased against the cam surface by the compression spring; wherein, in response to relative rotation between the input member and the output member, the cam surface displaces the follower along a line of action coaxial or parallel with the longitudinal axes of the pocket and springs, and wherein the line of action does not intersect the rotational axis.

16 . The clutch mechanism of claim 15 , wherein the pocket is a first pocket, the spring is a first spring, and the follower is a first follower, and wherein the clutch mechanism further includes a second pocket that receives a second spring that biases the second follower against the cam surface.

17 . The clutch mechanism of claim 15 , wherein the spring is a first a spring, and the clutch mechanism further includes a second compression spring received by the pocket that biases the follower against the cam surface.

18 . The clutch mechanism of claim 15 , wherein the pocket is formed on the output member and the cam surface is formed on the input member, and wherein the output member is arranged within the input member.

19 . The clutch mechanism of claim 15 , wherein the pocket is a first pocket formed on a hub, and wherein the hub further includes a second pocket that is arranged perpendicular to the first pocket.

20 . The clutch mechanism of claim 19 , wherein the hub further includes a third pocket that is arranged perpendicular to the second pocket.

Assignees

• Milwaukee Electric Tool Corp

Inventors

• Carlson Mitchell

Classifications

• F16D2023/123

  Clutch actuation by cams, ramps or ball-screw mechanisms · CPC title

• F16D23/12

  Mechanical clutch-actuating mechanisms arranged outside the clutch as such (specific for combined clutches F16D21/00; mechanisms specific for synchronisation F16D23/02) · CPC title

• F16D15/00

  Clutches with wedging balls or rollers or with other wedgeable separate clutching members (freewheels, freewheel clutches F16D41/00) · CPC title

• B25F5/001 Primary

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

• F16D7/021 Primary

  with radially applied torque-limiting friction surfaces (F16D7/022 takes precedence) · CPC title