Speed wrench

#This invention is a hand tool of the ratchet type wherein a planetary gear system is provided to enable the user to selectively vary the output speed for a given input. In its preferred form the tool is a ratchet type socket wrench.

#Hand and power tools have previously been provided with planetary gear systems for the purpose of increasing or decreasing output torque with resultant change in output speed. In some cases, multiple or variable output torques have been provided by the user selectively controlling the rotation of one or more of the members in the gear system. In the prior art, however, the means for selectively controlling one or more of the gear system members has involved the use of clutches or shifting means or other mechanical means.

#In the present invention a hand tool of the ratchet type is provided with planetary gear means controlled by a hand grip in such a way that the user may conveniently control the output speed without having to select or adjust separate control means.

#FIG. 1 is a vertical section of one embodiment of this invention, taken along line 1--1 of FIG. 2;

#FIG. 2 is a sectional view taken at the line 2--2 shown in FIG. 1;

#FIG. 3 is a sectional view taken at the line 3--3 shown in FIG. 1;

#The preferred embodiment of this invention is an improvement to a conventional ratchet wrench which provides for variable speed of the output of the wrench. The conventional portion includes a handle 10, an output member, generally designated 12 and ratchet means 14. Typically, handle 10 has an enlarged integral end portion 16 with cavity 18 therein for receiving the output member 12, and the ratchet means 14. The output member 12 is of circular cross section and rotatable in cavity 18. Generally, output member includes a ratchet gear portion of relatively large diameter with ratchet teeth around its periphery, and an adapter 22 which extends through an opening in the end portion 16. Adapter 22 is shaped to accept a driving attachment such as a socket, or the like (not shown).

#The ratchet means 14 may comprise a pawl 24, including an extension forming a stub shaft 25, rotatably received in cavity 18, an adjuster bar 26, and a spring and ball detent 28. Pawl 24 conventionally may have a tooth 30 in engagement with a notch in the adjuster bar 26 so that sliding movement of the adjuster bar 26, between detent positions, imparts limited rotative movement to the pawl 24. The pawl 24 may also have ratchet teeth to cooperatively engage the teeth on the ratchet gear portion 20 of the output member 12, comprising a conventional ratchet drive mechanism. This mechanism will allow the output member 12 to turn freely, relative to the handle, in one direction (clockwise with the ratchet means 14 in the position shown in the drawings) but not in the opposite direction. Typically, a sufficient amount of lost motion is built into the ratchet mechanism so that as the output member 12 rotates in one direction relative to the handle 10, the teeth of the pawl 24 will be pushed out of engagement with each successive tooth of the ratchet gear 20 without moving the adjuster bar 26 out of its detent position. When an attempt is made to turn the output member 12 in the opposite direction, however, the teeth of the pawl 24 and output member 12 lock up preventing relative rotation. In an ordinary ratchet wrench the ratchet mechanism acts as a one-way direct drive coupling between the handle and the output so that reciprocating motion of the handle is converted to intermittent one-way motion of the output.

#It should be recognized that the foregoing is a brief description of a conventional ratchet type socket wrench having a handle 10 disposed at a right angle to the adapter 22. This description is provided for clarity and understanding of Applicant's improvement; however, the invention is not limited to this form of ratchet mechanism, or even to a socket wrench. The invention is easily adapted for use with ratchet screw drivers, drills or other tools regardless of the specific ratcheting mechanism or the disposition of the handle with respect to the output of the tool.