Bias and Reversing Mechanism for Roller Clutch Ratchet
AssigneeSnap-on Incorporated
InventorDavid Ross
Life of this patent
Estimating the term…
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.
Claims20
A reversible ratchet apparatus, comprising:
- a ratchet body;
- a cage member coaxially disposed within the ratchet body;
- a reverser sleeve coaxially disposed within the cage member;
- a drive member including an axle portion sized to be rotatably contained by the reverser sleeve;
- a roller constrained by the cage member between the ratchet body and the drive member;
- and
- a biasing member configured to exert a continuous rotational biasing force between the reverser sleeve and the cage member;
- wherein the drive member and the reverser sleeve are constrained in either of a first angular displacement or a second angular displacement relative to each other.
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 axially extending 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 and coaxial with the axle portion, the drive body including a scalloped outer surface;
- rollers respectively constrained between a corresponding pair of the fingers and 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 a first angular displacement or a second angular displacement 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.
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.
Dependencies are inferred from the claim text.