Dual pawl ratchet mechanism and reversing method
A dual-pawl ratchet wrench mechanism is disclosed having a stop mechanism for limiting over-travel of a reversing lever for selecting drive directions. In one form, the wrench mechanism includes a ball and spring assembly that cooperate with recesses to define proper positions for the reversing lever, and one or more ramps are provided between the recesses to promote tactile feel and to promote the reversing lever being rotated to a proper position. In some forms, the stop mechanism is formed on a stationary portion, such as a spacer or the wrench body, and a portion of the reversing lever. The design simplifies manufacturing, such as by simplifying assembly and minimizing the need for securements. Additionally, the reversing lever is assembled with the mechanism in a manner to improve sealing.
1. A reversible ratchet device comprising:
a body having opposing first and second sides;
a cavity defined within the body and communicating with the first and second sides;
a ratchet gear having a drive portion projecting out of the cavity adapted to transmit torque and a toothed portion rotatably disposed within the cavity;
first and second pawls adapted to selectively couple with the ratchet gear;
first and second selector posts respectively extending from the first and second pawls;
a reversing lever disposed within the cavity and movable between first and second positions, the reversing lever adapted to selectively impede rotation of the ratchet gear in a first drive direction, thus allowing torque to be transmitted in the first drive direction, and selectively permit rotation of the ratchet gear in a second drive direction opposite the first drive direction when the reversing lever is moved to the first position, and the reversing lever adapted to selectively impede rotation of the ratchet gear in the second drive direction, thus allowing torque to be transmitted in the second drive direction, and selectively permit rotation of the ratchet gear in the first drive direction when the reversing lever is moved to the second position, the reversing lever having first and second hooks adapted to respectively engage the first and second selector posts and prevent rotation of the reversing lever beyond the first and second positions;
a spacer disposed within the cavity proximate the reversing lever and having a bore extending therethrough; and
a member disposed in the bore and adapted to provide a bias force against the reversing lever,
wherein the reversing lever includes a surface with a first recess for receiving the member when the lever is in the first position and a second recess for receiving the member when the lever is in the second position.
2. The reversible ratchet device of claim 1 , wherein the surface includes a raised portion disposed between the first and second recesses, the raised portion including a peak and first and second ramps respectively leading from the peak to the first and second recesses.
3. The reversible ratchet device of claim 1 , wherein the first and second ramps each has a generally linear slope.
4. The reversible ratchet device of claim 1 , wherein the spacer is stationary relative to the ratchet body.
5. The reversible ratchet device of claim 1 , further comprising:
a cover plate coupled to the first side of the body; and
a bias member coupled to the member and the cover plate and adapted to provide the bias force.
6. A reversible ratchet device comprising:
a body having first and second sides and a cavity defined therein, the cavity being covered at the first side;
a ratchet gear having a toothed portion disposed within the cavity and a drive portion adapted to transmit torque and extending from the cavity through one of the first and second sides;
a pawl mechanism adapted to selectively couple with the ratchet gear;
a reversing lever movable between first and second positions, the reversing lever adapted to selectively impede rotation of the ratchet gear in a first drive direction, thus allowing torque to be transmitted in the first drive direction, and selectively permit rotation of the ratchet gear in a second drive direction opposite the first drive direction when the reversing lever is moved to the first position, and the reversing lever adapted to selectively impede rotation of the ratchet gear in the second drive direction, thus allowing torque to be transmitted in the second drive direction, and selectively permit rotation of the ratchet gear in the first drive direction when the reversing lever is moved to the second position, the reversing lever having first and second hooks adapted to respectively engage the first and second selector posts and prevent rotation of the reversing lever beyond the first and second positions;
a spacer disposed within the cavity of the ratchet body between the reversing lever and the first side, the spacer having a bore formed therein; and
a member disposed within the bore and biased against the reversing lever,
wherein the reversing lever includes a surface with a first recess for receiving the member when the lever is in the first position and a second recess for receiving the member when the lever is in the second position.
7. The reversible ratchet device of claim 6 , wherein the member is a ball biased against the surface by a bias member.
8. The reversible ratchet device of claim 7 , wherein the bias member is a spring.
9. The reversible ratchet device of claim 6 , wherein the spacer is stationary relative to the body.
10. The reversible ratchet device of claim 6 , further comprising a cover plate coupled to the body and covering the cavity at the first side, the member being biased against the cover plate and the surface.
11. The reversible ratchet device of claim 10 , wherein the spacer is disposed within the cavity between the reversing lever and the cover plate.
12. The reversible ratchet device of claim 6 , wherein the surface includes a raised portion disposed between the first and second recesses, the raised portion including a peak and first and second ramps respectively leading from the peak to the first and second recesses.
13. The reversible ratchet device of claim 12 , wherein the first and second ramps each has a generally linear slope.
14. The reversible ratchet device of claim 6 , wherein the cover plate includes an aperture and the drive portion extends from the toothed portion through the aperture.