Ratcheting tool with pawl spring retainer

A ratchet tool has a ratchet body with a cavity therein and a ratchet gear and a pawl disposed in the cavity and a bias spring disposed for resiliently urging the pawl into engagement with the gear, and a retaining member disposed in a recess formed in one or the other of the body and the gear and engaging the spring for retaining it in place.

BACKGROUND

This application relates to hand tools and, specifically, to ratcheting tools, such as wrenches or the like, provided with a ratchet mechanism. The application relates in particular to techniques for retaining the pawl spring of a ratchet mechanism.

Various types of ratchet mechanisms for hand tools are known. Such mechanisms typically include a head or a body which carries or defines a gear adapted to be coupled to a fastener or other workpiece for rotation thereof. The ratchet mechanism is typically provided with one or more pawls engageable with the gear teeth for either driving engagement therewith or ratcheting movement relative thereto, depending upon the direction of rotation of the head. The pawl or pawl assembly is biased into engagement with the gear by a suitable bias mechanism, and various types of retaining mechanisms have been provided for retaining the bias mechanism in place.

The bias and retention mechanisms are frequently complicated and difficult to assemble and/or to machine, adding to the cost of the tool.

SUMMARY

There is disclosed in this application a ratchet tool which avoids the disadvantages of prior tools, while affording additional structural and operating advantages.

An aspect of the disclosed tool is the provision of a pawl bias retention technique which is of relatively simple and economical construction.

In an embodiment, a ratchet tool includes a ratchet body having a cavity therein, a ratchet gear disposed in the cavity, a pawl disposed in the cavity for engagement with the gear, a bias spring disposed for resiliently urging the pawl into engagement with the gear, a recess formed in one of the body and the gear, and a retaining member disposed in the recess and engaging the spring for retaining the spring in place.

Also in an embodiment, in a ratchet tool having a body with a cavity and ratchet gear and a pawl disposed in the cavity for engagement with each other and a bias spring disposed in the cavity, there is provided a clip disposed in the cavity around the gear for engagement with the bias spring to hold the bias spring against the pawl for resiliently biasing the pawl into engagement with the gear.

There is also disclosed a method of retaining a pawl spring in a ratchet tool having a body with a cavity therein and a ratchet gear disposed in the cavity, the method comprising providing a recess in one of the body and the gear, and disposing a retaining member in the recess in engagement with the spring for holding the spring against the pawl to resiliently urge the pawl into engagement with the gear.

DETAILED DESCRIPTION

Referring to the drawings, there is illustrated a ratchet tool in the form of an end wrench10having a ratchet head11at one end thereof and being provided with an open-end wrench head at the opposite end thereof, the ratchet head11being in the form of a ratcheting box end. While the ratchet head11is shown in the form of a ratcheting box end on an end wrench, this is simply for purposes of illustration, and it will be appreciated that the ratchet head could be provided on other types of wrenching tools, and ratchet heads in forms other than a box end could also be provided. While the ratchet head11is illustrated as being integral with the wrench10, it will be appreciated that it could also be movable or indexable relative to the wrench handle in a known manner.

The ratchet head11has a body12with opposed end faces13and14. Formed through the body12from the end face13to the end face14is a circular bore15, having a counterbore16which defines an annular shoulder17. Also formed in the body12adjacent to the wrench handle is a generally part-cylindrical lobe18, which communicates with the counterbore16for cooperation therewith and with the bore15to define a cavity19. Also formed in the inner surface of the body12intermediate the end faces13and14and communicating with a cavity19is a recess in the form of a part-circular groove20. Also formed in the inner surface of the body adjacent to the end face13is a circular groove21.

Disposed in the cavity19is a ratchet mechanism22including an annular gear23having a cylindrical body24provided with external, circumferentially spaced and axially extending teeth25. Projecting axially from the opposite ends of the body24is a reduced-diameter cylindrical hub26, which cooperates with the body to define a pair of annular shoulders27and27a. Extending axially through the gear23is a bore28defining a plurality of drive surfaces29. While the drive surfaces29are illustrated as arranged in a 12-point configuration, it will be appreciated that other drive configurations could be provided, such as hexagonal, double-hex, square and the like. The gear23is dimensioned to fit in the cavity19, with the lower end of the hub26disposed in the bore15and the body24disposed in the counterbore16with the lower shoulder27engageable with the shoulder17, so that the gear23is freely rotatable relative to the body12.

The ratchet mechanism22also includes a pawl30, which is disposed in use in the lobe18, the pawl having an arcuate outer surface31which generally follows the contour of the peripheral wall of the lobe18, and a plurality of teeth32disposed facing the gear23. Formed in one end of the pawl30is a socket33(FIG. 4) receiving one end of a helical compression spring34. It can be seen that the pawl30is generally wedge-shaped, the spring34being disposed so as to resiliently urge the pawl30toward the narrow end of the lobe18, so as to generally urge the pawl30into wedging engagement between the gear23and the sidewall of the lobe18, as can be seen inFIG. 4, all in a known manner. Thus, the pawl teeth32are resiliently urged into meshing engagement with the gear teeth25.

The spring34is retained in place by a retaining clip35, which has a part-circular portion36disposable in the groove20and having a tab portion37at an end thereof which extends laterally outwardly into the lobe18of the cavity19and engages a bent coil38of the spring34. It will be appreciated that the tab portion37, which may engage the peripheral wall of the lobe18, serves as an anchor against which the spring34bears.

The ratchet mechanism22is retained in place by an annular cover plate40, which is dimensioned to seat in the open end of a counterbore16in opposed facing relationship with the upper shoulder27aof the gear23. The cover plate40has a circumferential groove41in its outer surface (FIG. 3) which receives a snap ring42, which is dimensioned to also be received in the groove21in the body12for retaining the cover plate40in place, and, thereby, retaining the ratchet mechanism22in place. It can be seen that the cover plate40cooperates with the shoulder17of the body12to serve as bearings for the pawl30, all in a known manner.

The gear teeth25and pawl teeth32are arranged so that, when the gear23is engaged with an associated workpiece, when the wrench10is rotated in one direction about the rotational axis of the gear23, the pawl teeth32will be urged more firmly into meshing engagement with the gear teeth25for imparting torque to the associated workpiece and, when the wrench is rotated in the opposite direction, the pawl teeth32will ratchet past the gear teeth25, this movement being accommodated by the spring34, to permit the wrench head11to be repositioned rotationally relevant to the workpiece, all in a known manner.

While the recess or groove20for the retaining clip35is disposed in the body12, this need not necessarily be the case. For example, it would be possible to form the groove in the gear23, thereby dividing the gear teeth25into axially spaced-apart sections. Also, while the recess is shown in the nature of a groove20, it will be appreciated that other arrangements could be possible. For example, a further counterbore could be formed in the bore15defining a shoulder upon which the retaining clip35could be seated. While the ratchet head11is a unidirectional ratchet, it will be appreciated that the general principles of the invention would be applicable to bi-directional or reversible ratchets.

The ratchet head11and parts of the ratchet mechanism22may be formed of suitable metals or other materials commonly used in ratchet mechanisms.

In view of the foregoing, it can be seen that there has been provided a ratchet tool which has an improved pawl spring retention, while being characterized of ease of assembly and simplicity and economy of construction, the parts being easily and inexpensively machineable.