Ratchet mechanism for ratchet wrench

Patent metadata

Field	Value
Publication number	US-10864616-B2
Application number	US-201514698348-A
Country	US
Kind code	B2
Filing date	Apr 28, 2015
Priority date	May 15, 2014
Publication date	Dec 15, 2020
Grant date	Dec 15, 2020

Abstract

A tool that includes a wrench body a first drive end, and a ratchet gear disposed in an aperture in the first drive end. A first cavity is formed in the first drive end and in communication with the aperture. First and second pawls are disposed in the first cavity, and the first and second pawls each includes teeth adapted to engage the ratchet gear. A second cavity is formed in the first drive end and is in communication with the first cavity. The second cavity receives a reversing disc adapted to selectively engage the first and second pawls to cause engagement and dis-engagement of the first and second pawls with the ratchet gear. By orienting the pawls to allow the second cavity to have a minimum depth, the head of the wrench can be stiffened, thereby increasing fatigue strength and rigidity of the wrench.

First claim

What is claimed is:

1. A tool having a drive end with a ratchet gear disposed in an aperture and that includes a receiving portion adapted to engage and provide a torque to a work piece, the tool comprising:
first and second pawls respectively having first and second pawl teeth that are each selectively engageable and disengageable with the ratchet gear;
a reversing lever having a stem portion and including a notch formed in the stem portion; and
a reversing disc including a channel extending from an edge of the reversing disc towards a central portion of the reversing disc in a radial direction, wherein the channel is adapted to receive the stem portion and allow the reversing disc to slide perpendicular to a longitudinal axis of the stem portion and into the notch, the reversing disc is adapted to co-rotate with the reversing lever when the reversing lever is moved between first and second positions to cause the selective engagement of one of the first and second pawl teeth with the ratchet gear and disengagement of the other of the first and second pawl teeth from the ratchet gear, thereby causing the receiving portion to provide the torque to the work piece in one of either first and second rotational directions and ratchet in the other of the first and second rotational directions.

2. The tool of claim 1 , wherein the reversing lever includes a lever portion and is positioned on an exterior of the drive end.

3. The tool of claim 1 , wherein the drive end includes a recess formed on an exterior thereof, and wherein the recess receives a lever portion of the reversing lever.

4. The tool of claim 1 , further comprising a first cavity disposed in the drive end and in communication with the aperture, wherein the first and second pawls are disposed in the first cavity.

5. The tool of claim 4 , further comprising a second cavity disposed in the drive end and in communication with the first cavity, the second cavity having a depth less than the first cavity, wherein the reversing disc is disposed in the second cavity.

6. The tool of claim 5 , wherein each of the first and second pawls includes a selector post.

7. The tool of claim 6 , wherein the reversing disc includes hooks adapted to selectively engage the respective selector posts to cause the selective engagement of one of the first and second pawl teeth with the ratchet gear and disengagement of the other of the first and second pawl teeth from the ratchet gear.

8. The tool of claim 5 , further comprising a cover plate disposed on and closing the first and second cavities.

9. The tool of claim 5 , wherein the first and second pawls each includes a relief portion on a side opposite the respective first and second pawl teeth.

10. The tool of claim 9 , further comprising a spring disposed in the first cavity and in engagement with the relief portions of the first and second pawls, the spring is adapted to limit movement of one of the first and second pawl teeth away from the ratchet gear when such first and second pawl teeth is in selective engagement with the ratchet gear.

11. The tool of claim 1 , wherein a portion of the edge that the channel extends from is curved.

12. A ratchet mechanism for a tool adapted to engage and apply a torque to a work piece, comprising:
a ratchet gear having:
a receiving portion;
an engagement surface surrounding the receiving portion and adapted to operatively engage the work piece; and
ratchet teeth disposed on an outer circumferential surface;

first and second pawls respectively having first and second pawl teeth adapted to selectively engage the ratchet teeth;
a reversing lever having a stem portion and including a notch formed in the stem portion; and
a reversing disc including a channel extending from an edge of the reversing disc towards a central portion of the reversing disc in a radial direction, wherein the channel is adapted to receive the stem portion and allow the reversing disc to slide perpendicular to a longitudinal axis of the stem portion and into the notch, the reversing disc is adapted to co-rotate with the reversing lever when the reversing lever is moved between first and second positions to cause the selective engagement of one of the first and second pawl teeth with the ratchet teeth and disengagement of the other of the first and second pawl teeth from the ratchet teeth, thereby causing the receiving portion to provide the torque to the work piece in one of either first and second rotational directions and ratchet in the other of the first and second rotational directions.

13. The ratchet mechanism of claim 12 , further comprising a spring disposed between the first and second pawls and adapted to bias the first and second pawls away from one another.

14. The ratchet mechanism of claim 12 , wherein the reversing lever includes a lever portion operable by a user to select either one of the first and second rotational directions.

15. The ratchet mechanism of claim 12 , wherein each of the first and second pawls includes a selector post; and
the reversing disc includes hooks adapted to selectively engage the selector posts to selectively cause the selective engagement of one of the first and second pawl teeth with the ratchet teeth and disengagement of the other of the first and second pawl teeth from the ratchet teeth.

16. The ratchet mechanism of claim 12 , wherein the first and second pawls each includes a relief portion on a side opposite the pawl teeth.

17. The ratchet mechanism of claim 16 , further comprising a spring in engagement with the relief portions of the first and second pawls, the spring is adapted to limit movement of one of the first and second pawl teeth away from the ratchet teeth when such one of the first and second pawl teeth is selectively engaged with the ratchet teeth.

18. The ratchet mechanism of claim 12 , wherein the reversing disc is disposed in a cavity of the tool having a minimum depth to accommodate the reversing disc.

19. The ratchet mechanism of claim 18 , wherein the reversing disc includes a tab portion extending from a radial side.

20. The ratchet mechanism of claim 19 , wherein the cavity includes first and second stops formed by a non-circular shape of the cavity.

Assignees

• Snap On Tools Corp

Inventors

• Thompson Christopher D
• Eggert Daniel M
• Ross David T

Classifications

• F16D41/12

  with hinged pawl co-operating with teeth, cogs, or the like (F16D41/02, F16D41/24 take precedence) · CPC title

• B25B13/463 Primary

  a pawl engaging an externally toothed wheel · CPC title

• B25B13/08

  of open jaw type · CPC title

• F16D41/16

  the action being reversible · CPC title

• B25B23/00

  Details of, or accessories for, spanners, wrenches, screwdrivers (bolt tensioners B25B29/02) · CPC title