Ball deflecting chamfer

Patent metadata

Field	Value
Publication number	US-9505107-B2
Application number	US-201313894075-A
Country	US
Kind code	B2
Filing date	May 14, 2013
Priority date	May 14, 2013
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

A cam shaft is disclosed having an asymmetric chamfer for guiding a ball bearing deeper into a cam shaft groove to avoid ball loss when an immediate deceleration force is applied. The chamfer spaces the ball from an opening in the front face of a hammer that moves axially relative to the cam shaft when a tool having the cam shaft and hammer is dropped. The ball is therefore less likely to escape through the front opening of the hammer when the impact wrench is dropped.

First claim

What is claimed is:

1. A cam shaft adapted for use in a tool, the cam shaft comprising:
a base;
a shaft extending from the base in an axial direction;
a cam shaft groove disposed circumferentially around the shaft and adapted to movably retain a ball, the cam shaft groove including groove portions respectively extending at angles relative to the axial direction and intersecting at a vertex; and
a chamfer defined within the cam shaft groove proximate the vertex and adapted to deflect the ball away from the vertex when a force in the axial direction is applied to the cam shaft.

2. The cam shaft of claim 1 , further comprising holes disposed in the base and adapted to respectively receive fasteners.

3. The cam shaft of claim 1 , wherein the chamfer is defined within only one of the groove portions.

4. An tool comprising:
a cam shaft including:
a base;
a shaft extending from the base in an axial direction;
a cam shaft groove disposed circumferentially around the shaft and adapted to movably retain a ball, the cam shaft groove including two groove portions respectively extending at angles relative to the axial direction and intersecting at a vertex; and
a chamfer defined within the cam shaft groove proximate the vertex and adapted to deflect the ball away from the vertex when a force in an axial direction is applied to the cam shaft;

a hammer having an opening defined therein adapted to receive the ball, the opening extending through the hammer to a front face of the hammer; and
a bias member disposed between the cam shaft and the hammer.

5. The tool of claim 4 , further comprising a washer disposed between the bias member and the hammer.

6. The tool of claim 5 , further comprising a bearing disposed between the washer and the hammer.

7. The tool of claim 4 , further comprising an anvil, wherein the hammer is adapted to rotate and impact the anvil.

8. The tool of claim 7 , wherein the hammer includes hammer lugs, the anvil includes anvil lugs, and the hammer lugs are adapted to rotate and respectively impact the anvil lugs.

9. The tool of claim 8 , wherein the anvil includes an impact end adapted to apply torque and/or impact to a work piece.

10. The tool of claim 4 , further comprising holes disposed in the base and adapted to receive a fastener.

11. The tool of claim 4 , wherein the chamfer is defined within only one of the groove portions.

12. The tool of claim 4 , wherein the opening includes hammer grooves.

13. A tool comprising:
a power source adapted to supply power to the tool;
a trigger adapted to selectively cause power to be distributed the power from the power source;
an impact end adapted to apply an impact force and/or torque to a work piece;
a cam shaft including:
a base;
a shaft extending from the base in an axial direction;
a cam shaft groove disposed circumferentially around the shaft and adapted to movably retain a ball, the cam shaft groove including two groove portions extending at respective angles relative to the axial direction and intersecting at a vertex; and
a chamfer defined within the cam shaft groove proximate the vertex and adapted to deflect the ball away from the vertex when a force in the axial direction is applied to the cam shaft;

a hammer having an opening defined therein adapted to receive the ball, the opening extending through the hammer and to a front face of the hammer; and
a bias member disposed between the cam shaft and the hammer.

14. The tool of claim 13 , further comprising a washer disposed between the bias member and the hammer.

15. The tool of claim 14 , further comprising a bearing disposed between the washer and the hammer.

16. The tool of claim 15 , wherein the hammer includes hammer lugs, the anvil includes anvil lugs, and the hammer lugs are adapted to rotate and respectively impact the anvil lugs.

17. The tool of claim 13 , further comprising an anvil, wherein the hammer is adapted to rotate and impact the anvil.

18. The tool of claim 13 , further comprising holes disposed in the base and adapted to respectively receive a fastener.

19. The tool of claim 13 , wherein the chamfer is defined within only one of the groove portions.

20. The tool of claim 13 , wherein the opening includes hammer grooves.

Assignees

• Snap On Incorporated

Inventors

• Putney Gordon A

Classifications

• F16H25/08

  for interconverting rotary motion and reciprocating motion (F16H23/00 takes precedence) · CPC title

• B25D11/104

  with rollers or balls as cam surface · CPC title

• B25B21/02 Primary

  with means for imparting impact to screwdriver blade or nut socket · CPC title

• Y10T74/2101

  Cams · CPC title

• B25D11/102

  the rotating axis of the cam member being coaxial with the axis of the tool · CPC title