Pawl control mechanism for a ratchet tool

A control mechanism for a ratchet tool includes a switch pivotably received in a chamber in the head of the tool and a pawl is received in a recess so as to be matched with a gear wheel in the head. The pawl is located at located at a mediate portion of a depth of the chamber in the head. The switch has two holes in each of which a pushing member a spring are received. The pushing member is received in the hole and covered by an inside of the chamber when the switch is not pivoted. The user may push either one of two ends of the pawl toward the chamber to shift one of the pushing members to be in alignment with one of the convex portions. The pushing member that is shifted pushes the convex portion and pivots the pawl to be matched with the gear wheel.

FIELD OF THE INVENTION

The present invention is a pawl control mechanism that includes a switch which is pushed at either one of two ends toward the chamber in the head of the tool to position the pawl.

BACKGROUND OF THE INVENTION

Three conventional ratchet tools that are known to applicant are disclosed respectively in U.S. Pat. No. 6,516,692 B1, U.S. Pat. No. 6,609,444 B1, and US-2003/0010159 A1. Each of the disclosed ratchet tools of the prior art involves a switch which controls the movement of the pawl for deciding the direction that the gear wheel when output a torque by rotating the tool. The switch of the U.S. Pat. No. 6,516,692 B1, U.S. Pat. No. 6,609,444 B1 are moved parallel to the surface of the head of the ratchet tool to move the pawl. The switch of US-2003/0010159 A1 is rotated an angle about a shaft and the rotational movement is happened on the surface of the head of the ratchet tool. In other words, the user operates the switch member of the three conventional ratchet tools in a plain that is parallel to the surface of the head of the tool. This action is not convenient when the user's finger is attached with grease.

The present invention intends to provide a pawl control mechanism for a ratchet tool wherein the switch is operated by pushing either one of two ends of the switch toward the head of the tool.

SUMMARY OF THE INVENTION

The present invention relates to a ratchet tool which comprises a head and a gear wheel is rotatably received in a hole in the head and a recess for receiving a pawl therein is defined in an inner periphery of the hole. The pawl has a toothed surface in a first end thereof so as to be matched with a toothed outer periphery of the gear wheel. Two convex portions extend from two ends of a second end of the pawl.

A chamber is defined in a side of the head and a switch is pivotably received in the chamber. The recess is in communication with the chamber and located at a mediate portion of a depth of the chamber. The switch has an insertion which is pivotably received in the chamber and an operation plate is located on an end of the insertion and each one of two ends of the operation plate can be pushed toward the chamber to pivot the insertion. Two holes are defined in the insertion and located from a distance from the recess when the switch is not pivoted. Each hole in the insertion has a pushing member and a spring received therein. The pushing member is biased by the spring and sized to be received in the hole by an inside of the chamber. The two pushing members are alternatively shifted to a position in alignment with one of the convex portions of the pawl so that one of the convex portions of the pawl is pushed toward the gear wheel.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring toFIGS. 1 to 3and9, the ratchet tool of the present invention comprises a head10having a hole11defined through and a gear wheel20is rotatably received in the hole11. A recess12is defined in an inner periphery of the hole11and a pawl30is received in the recess12. The pawl30has a toothed surface in a first end thereof so as to be matched with a toothed outer periphery of the gear wheel20. Two convex portions31extend from two ends of a second end of the pawl30.

A chamber13is defined in a side of the head10and communicates with the recess12which is located at a mediate portion of a depth of the chamber13as shown inFIG. 8. Two notches141,142and a positioning hole143are defined in the inside of the chamber13wherein the positioning hole143is located between the two notches141,142. A switch50composed of an insertion500and an operation plate501is pivotably received in the chamber13by a pin70which extends through a pin hole51in the insertion500which is inserted in the chamber13and is engaged with the positioning hole143in the chamber13. The pin70is a T-shaped member and includes a horizontal portion72and an upright vertical portion71which extends through the pin hole51, the horizontal portion72is located beside a side the pawl30. The operation plate501is located on an end of the insertion500and accessible form an outside of the head10. Each one of two ends531,532of the operation plate501can be pushed toward the chamber13to pivot the insertion500.

Two holes52are defined through in the insertion500and located from a distance from the recess12when the switch50is not pivoted as shown inFIG. 8. Each hole52in the insertion500has a pushing member17, a spring16and a bead15received therein. The pushing member17and the bead15are biased by two ends of the spring16. The pushing member17is sized to be received in the hole52by an inside of the chamber13when the switch50is not pivoted as shown inFIG. 8. The chamber13further includes two elongate notches141,142so that the beads15are movable in the notches141,142when the switch50is pivoted.

FIGS. 4 to 7show that the two pushing members17are alternatively shifted to a position in alignment with one of the convex portions31of the pawl30. When either one of the pushing members17is shifted to a position to push one of the convex portions31of the pawl30toward the gear wheel20, the pawl30is positioned to match with the gear wheel20.

The switch50is operated by pushing either of the two ends531,532toward the chamber13so as to position the pawl30. The switch50is easily to be operated regardless of the condition of the finger of the user and this is especially advantage for the user whose fingers are attached with grease.