Ratchet wrench and pawl mechanism

Patent metadata

Field	Value
Publication number	US-9709141-B2
Application number	US-201514839011-A
Country	US
Kind code	B2
Filing date	Aug 28, 2015
Priority date	Aug 28, 2015
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

A pawl mechanism that reduces the possibility of pawl spring over-compression and damage. The invention can include bumpers disposed near the internal surfaces of the pawls and can space the internal surfaces when the pawls contact one another to reduce the amount of compression applied to the pawl spring. The pawl spring can be inserted into respective cavities on the pawls to further prevent additional compression of and damage to the pawl spring.

First claim

What is claimed is:

1. A pawl mechanism, comprising:
first and second pawls each having opposing first and second sides and a third side coupling the first and second sides, each of the first sides has first teeth and each of the third sides has a cavity extending therefrom;
a pawl spring disposed between the first and second pawls; and
a first bumper disposed on the first pawl proximate the third side of the first pawl and extending inwardly from the third side of the first pawl to create a first indent within the first pawl proximate the cavity of the first pawl, wherein the first indent has a first cross sectional width larger than a second cross sectional width of the cavity of the first pawl and wherein the pawl spring at the third side is spaced from the first bumper.

2. The pawl mechanism of claim 1 , further comprising a second bumper disposed on the second pawl proximate the third side of the second pawl and extending inwardly from the third side of the second pawl to create a second indent within the second pawl.

3. The pawl mechanism of claim 1 , wherein the pawl spring engages the cavity of each of the first and second pawls.

4. The pawl mechanism of claim 1 , wherein the first pawl further includes a first post, and the cavity extends from the third side of the first pawl past the first post.

5. The pawl mechanism of claim 1 , wherein the first bumper extends around a periphery of the third side of the first pawl.

6. A pawl mechanism for a tool including a drive gear adapted to apply torque to a work piece and a reversing lever adapted to engage the pawl mechanism to select a rotational drive direction of the drive gear, the pawl mechanism comprising:
first and second pawls each having opposing first and second sides and a third side coupling the first and second sides, each of the first sides having first teeth and each of the third sides having a cavity extending therefrom;
a pawl spring separating the first and second pawls; and
a first bumper disposed on the first pawl proximate the third side of the first pawl and extending inwardly from the third side of the first pawl to create a first indent within the first pawl proximate the cavity of the first pawl, wherein the first indent has a first cross sectional width larger than a second cross sectional width of the cavity of the first pawl and wherein the pawl spring at the third side is spaced from the first bumper.

7. The pawl mechanism of claim 6 , wherein the second pawl includes a second bumper disposed proximate the third side of the second pawl and extending inwardly from the third side of the second pawl to create a second indent within the second pawl.

8. The pawl mechanism of claim 6 , wherein the pawl spring engages the cavity of each of the first and second pawls.

9. The pawl mechanism of claim 6 , wherein the first pawl further includes a first post, and the cavity extends from the third side of the first pawl past the first post.

10. The pawl mechanism of claim 6 , wherein the first bumper extends around a periphery of the third side of the first pawl.

11. The pawl mechanism of claim 9 , wherein the reversing lever engages the first post to select the drive direction.

Assignees

• Snap On Incorporated

Inventors

• Thompson Christopher
• Eggert Daniel

Classifications

• B25B13/46

  of the ratchet type, for providing a free return stroke of the handle · CPC title

• F16H31/002 Primary

  Hand-driven ratchets · CPC title

• B25B13/463 Primary

  a pawl engaging an externally toothed wheel · CPC title