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Bias assembly for ratchet tools

a ratchet wrench and assembly technology, applied in the field of ratchet pawl assemblies, can solve the problems of high torque needed to tighten or loosen the bolt, limited access to the bolt, awkward and difficult to use a traditional (non-ratcheting) tool, etc., to minimize the amount of counter-rotation, minimize the amount of wasted motion, and minimize the effect of playing in the ratchet wrench

Active Publication Date: 2013-12-24
SNAP ON INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The patent describes a bias assembly that helps reduce the amount of counter-rotation required to move a pawl in a ratchet tool. This ensures that the tool can shift gears easily and reduces the movement of the pawl when it is not needed. The bias assembly uses a leaf spring to provide a radial force to the pawl and helps it move along a smooth path. This helps minimize the space needed in the tool and reduces the cost of manufacturing and components. Overall, the invention improves the functionality and efficiency of ratchet tools by reducing the amount of counter-rotation required to shift gears.

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.

Method used

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  • Bias assembly for ratchet tools

Examples

Experimental program
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Embodiment Construction

[0025]Referring initially to FIG. 1, a ratchet head 10 of a ratchet wrench is shown having a body 11 and a bias assembly 12 for reducing waste rotation when the wrench is rotated and counter-rotated. In the present form, the bias assembly 12 includes a first spring 14, referred to herein as the selection spring 14, for biasing first and second pawls 16, 18 apart. The first and second pawls 16, 18 are selectively engagable with a ratchet gear 20 to select a drive direction and a slip or ratchet direction respectively corresponding to rotation and counter-rotation of the ratchet head 10. The selection spring 14 allows a reversing lever or drive direction selector or actuator 15 to act upon posts 17 of the pawls 16, 18 so that the selector 15 may shift one of the pawls 16, 18 into or out of engagement with the gear 20, and the selector spring 14 serves to shift the other of the pawls 18, 16 in the opposite manner as the one pawl 16, 18. Preferably, the selector 15 is operated to pull o...

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PUM

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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...

Claims

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Application Information

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Patent Type & Authority Patents(United States)
IPC IPC(8): B25B13/46
CPCB25B13/463
Inventor ROSS, DAVID T.WENTE, STEVEN R.
Owner SNAP ON INC
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