Bias and reversing mechanism for roller clutch ratchet

Patent metadata

Field	Value
Publication number	US-9296093-B2
Application number	US-201414261903-A
Country	US
Kind code	B2
Filing date	Apr 25, 2014
Priority date	Apr 25, 2014
Publication date	Mar 29, 2016
Grant date	Mar 29, 2016

Abstract

A roller clutch mechanism of a reversible ratchet tool is configured to include a biasing and reversing mechanism for biasing rollers in the roller clutch mechanism. A cage member of the roller clutch mechanism locates rollers in either a clockwise or counterclockwise position based on a selective position of the reverser mechanism. The reverser mechanism applies a constant bias to the cage member so that the rollers are constantly biased and quickly engage between the ratchet body and the drive head. The constant bias applied to the cage member reduces the ratcheting angle for improved performance of the reversible ratchet tool.

First claim

What is claimed is:

1. A reversible ratchet apparatus, comprising:
a ratchet body including an inner surface defining a circular aperture;
a cage member disposed within the ratchet body and including:
an annular base disposed within the circular aperture and cooperatively defining a cage aperture;
fingers axially extending from the annular base; and
a radial tab extending from the annular base into the cage aperture;

a reverser sleeve disposed within the cage member;
a drive member including an axle portion adapted to be retained by the reverser sleeve;
a roller retained by the cage member between the ratchet body and the drive member; and
a biasing member adapted to exert a biasing force between the reverser sleeve and the cage member;
wherein the drive member and the reverser sleeve are disposed in either of first or second displacements relative to each other.

2. The apparatus of claim 1 , wherein the biasing member includes a compression spring.

3. The apparatus of claim 1 , wherein the cage member is adapted to shift the roller from a first position to a second position on the drive member when the drive member and the reverser sleeve are shifted from the first displacement to the second displacement.

4. The apparatus of claim 3 , wherein the roller is sized to substantially reduce relative motion between the ratchet body and the drive member only in a first direction of rotation when the roller is in the first position, and to substantially reduce relative motion between the ratchet body and the drive member only in a second direction of rotation opposite the first direction of rotation when the roller is in the second position.

5. The apparatus of claim 1 , wherein the reverser sleeve is annularly shaped and includes an outer wall disposed within the cage aperture and an inner wall defining a first portion of a central aperture.

6. The apparatus of claim 5 , wherein the radial tab defines a second portion of the central aperture having a same diameter as the first portion of the central aperture.

7. The apparatus of claim 6 , wherein the reverser sleeve includes first and second ends, wherein a first biasing member is engaged between the first end and the radial tab, and a second biasing member is engaged between the second end and the radial tab.

8. The apparatus of claim 1 , wherein the drive member includes a drive body coaxial with the axle portion, the drive body includes a scalloped outer surface.

9. The apparatus of claim 8 , wherein the drive member further includes a drive lug extending from the drive body coaxial with the axle portion.

10. The apparatus of claim 9 , wherein the drive lug forms a square socket drive.

11. The apparatus of claim 8 , wherein the roller is retained between a plurality of the fingers between the inner surface of the ratchet body and the scalloped surface of the drive body.

12. The apparatus of claim 11 , further comprising an engagement member engaged between the drive member and the reverser sleeve, the engagement member adapted to retain the drive member and the reverser sleeve in either of the first or second displacements.

13. The apparatus of claim 12 , wherein the drive member includes a shoulder facing the reverser sleeve, the shoulder including a pocket adapted to retain a detent spring, wherein the reverser sleeve includes two detent cavities facing the shoulder and displaced from each other;
the engagement member includes a detent ball sized to fit in either one of the detent cavities and the detent spring is at least partially retained in the pocket and compressed between the detent ball and the drive member.

14. The apparatus of claim 12 , wherein the fingers are adapted to shift the roller from a corresponding first ramp on the scalloped surface to a corresponding second ramp on the scalloped surface when an angular displacement between the drive member and the semi-annular reverser sleeve is shifted from the first displacement to the second displacement.

15. The apparatus of claim 14 , wherein the roller is adapted to bind between the first ramp and the inner surface of the ratchet body to prevent relative motion between the ratchet body and the drive member only in a first direction when the roller is on the corresponding first ramp, and to bind between the second ramp and the inner surface of the ratchet body to prevent relative motion between the ratchet body and the drive member only in a second direction opposite the first direction when the roller is on the corresponding second ramp.

16. The apparatus of claim 1 , further comprising a reverser lever coupled to the reverser sleeve.

17. A reversible ratchet apparatus, comprising:
a ratchet body including an inner surface defining an inner wall of a circular aperture;
a cage member including an annular base, a plurality of fingers extending axially from a side of the annular base, the annular base disposed within the circular aperture to cooperatively define a cage aperture, and a radial tab extending from the annular base into the cage aperture;
a semi-annular reverser sleeve including an outer semi-annular wall sized to fit coaxially within the cage aperture and an inner semi-annular wall defining a first portion of a central aperture;
a drive member including an axle portion rotatably contained by the central aperture, a drive body coaxial with the axle portion, and a drive shaft extending from the drive body coaxial with the axle portion, the drive body including a scalloped outer surface;
rollers respectively constrained between a corresponding pair of the fingers between the inner surface of the ratchet body and the scalloped surface of the drive body;
an engagement member engaged between the drive member and the semi-annular reverser sleeve, the engagement member configured to constrain the drive member and the semi-annular reverser sleeve in either of first or second angular displacements relative to each other;
a biasing member disposed between the semi-annular reverser sleeve and the radial tab, the biasing member configured to exert a continuous rotational biasing force between the reverser sleeve and the cage member;
wherein the fingers are configured to shift the rollers from respective corresponding first ramps on the scalloped surface to corresponding second ramps on the scalloped surface when an angular displacement between the drive member and the semi-annular reverser sleeve is shifted from the first angular displacement to the second angular displacement,
and wherein the rollers are sized to respectively bind between the first ramps and the inner surface of the ratchet body to prevent relative motion between the ratchet body and the drive member only in a first direction of rotation when the rollers respectively engage the corresponding first ramps, and to respectively bind between the second ramps and the inner surface of the ratchet body to prevent relative motion between the ratchet body and the drive member only in a second direction of rotation opposite the first direction of rotation when the rollers respectively engage the corresponding second ramps.

18. A method for reducing backlash in a reversible ratchet tool, the method comprising:
configuring a circular array of rollers within a circular roller cage member for rotation around an axis within a ratchet body;
configuring a semi-annular reverser sleeve within the ratchet body for rotation around the axis; and
configuring a biasing member to exert a continuous rotational biasing force between the reverser sleeve and the cage member and about the axis.

Assignees

• Snap On Tools Corp
• Snap On Tools Corp

Inventors

• Ross David

Classifications

• B25B13/462 Primary

  the ratchet parts engaging in a direction radial to the tool operating axis · CPC title

• B25B13/46 Primary

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

• B25B23/00

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

• B25B15/04

  with ratchet action · CPC title

• B25B13/481

  for operating in areas having limited access · CPC title