Bias assembly for ratchet tools

Abstract

A ratcheting tool such as a reversible dual-pawl ratchet wrench is disclosed that minimizes wasted motion during ratchet slip or counter-rotation. The ratchet wrench includes a bias assembly that biases the pawls apart to bias a first, selected pawl for a selected drive direction towards engagement with a ratchet gear, and that the biases the selected pawl into a concentric alignment with the ratchet gear. In this manner, non-ratcheting initial rotation of the pawl due to counter-rotation prior to the pawl camming out of engagement with the ratchet gear is eliminated, thus eliminating wasted motion and maximizing the available angular sweep for the wrench.

Description

FIELD OF THE INVENTION[0001]The invention relates to ratchet pawl assemblies for ratchet tools and, in particular, to a bias assembly for reducing wasted motion for a ratchet tool or wrench.BACKGROUND[0002]Currently, hand tools utilizing ratchets are well-known. On a basic level, these ratchet tools operate so that rotation or drive in a first direction engages internal components so that the tool operates in the manner a traditional non-ratchet tool would to provide rotational drive to a workpiece such as a screw or a bolt, for instance. When the tool is rotated in a second direction opposite the first direction, the internal components are able to slip or ratchet over each other so that this rotation does not counter-drive the workpiece. Accordingly, a user of the tool can engage the tool with the work piece and maintain the tool engaged thereto while rotating and counter-rotating the tool to drive the workpiece. The user simply rotates the tool in the first direction for a portio...

AI Technical Summary

Benefits of technology

[0018]As described, a bias assembly is provided that provides a force against an engaged pawl to minimize the amount of counter-rotation necessary for the pawl and a ratchet gear to ratchet or slip relative to each other. Preferably, the bias assembly provides a force against the engaged pawl in a direction along a radius of the ratchet gear. It is also preferred that the bias assembly serves to bias the engaged pawl in a direction opposite the slip direction. This allows the ratchet tool to utilize minimum components for shifting pawls and selecting a drive direction, and allows the bias assembly to advance the pawl in the drive direction when the pawl has been cammed out of engagement with the ratchet gear due to counter-rotation thereof. Thus, the play in a ratchet wrench is minimized and counter-rotation used to ratchet the tool has a minimal amount of wasted motion.

[0019]In a preferred embodiment, the ratchet tool is a reversible dual-pawl wrench having a first bias member of the bias assembly, a pair of pawls biased apart by the first bias member, and a second bias member of the bias assembly which contacts and engages both of the pawls for providing a radial force thereto. The second bias member is preferably a leaf spring so that packaging space required in a head of the ratchet wrench is minimized. The position of the second bias member is preferably maintained by the pawls and features of the ratchet head so that fasteners or the like are not necessary, thereby minimizing manufacturing and component cost.

Problems solved by technology

Therefore, access to a bolt may be limited, and a high torque is needed to tighten or loosen the bolt.

A wrench used to tighten or loosen the bolt may only be able to rotate a small number of degrees before the path of the wrench brings the wrench into contact or interference with other components mounted in the engine compartment.

This means that the tool must be rotated these few degrees many times. It is often awkward and difficult to use a traditional (non-ratcheting) tool in these spaces as such requires making a small turn, and then removing and reengaging the tool with the bolt or other workpiece.

An issue with these ratchet tools is that, once the tool has been counter-rotated, the pawls and their teeth must re-engage with the ratchet gear to provide torque drive.

As a result, there is wasted rotational movement in order to dis-engage and re-engage the pawl.

When the tool is used in a space that provides little overall rotational sweep, this wasted movement can be significant.

The pawl itself is positioned against one or more rigid portions formed in the ratchet head, such as a channel For such devices, the pawl may bind with or grind against the channel so that operation of the tool is rendered difficult at times.

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