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Publication numberUS3250157 A
Publication typeGrant
Publication dateMay 10, 1966
Filing dateNov 6, 1963
Priority dateNov 6, 1963
Publication numberUS 3250157 A, US 3250157A, US-A-3250157, US3250157 A, US3250157A
InventorsRobert E Badger
Original AssigneeSnap On Tools Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Magnetic ratchet mechanism for wrenches and the like
US 3250157 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)


ATTORNEY United States Patent 3,250,157 MAGNETIC RATCHET MECHANISM FOR WRENCHES AND THE LIKE Robert E. Badger, Kenosha, Wis.,- assignor to Snap-On Tools Corporation, Kenosha, Wis., a corporation of Delaware Filed Nov. 6, 1963, Ser. No. 321,954 8 Claims. (Cl. 8163) This invention relates to ratchet wrenches and more particularly to magnetically controlled directional pawl type ratchet wrenches, although the teachings thereof may be employed with equal advantage for other devices.

It contemplates more especially the provision of magnetically displaceable ratchet pawl control devices used particularly for but not limited to ratchet wrenches to displace the pawl in relation to the ratchet wheel so that the ratcheting action can be effected in opposite directions, although this concept has a much wider application to mechanical devices of many different types and uses.

Ratchet wrenches have long been used and various mechanical expedients have been resorted to for the purpose of shifting the position of a pawl in relation to the ratchet wheel so that the ratcheting action can be resorted to for tightening and loosening nuts and other fasteners. Such mechanical pawl displacing expedients are satisfactory for predetermined periods, but are subject to wear and frictional problems which accumulate dirt,

oil debris and otherwise become ineflicient after extended periods of use. With the concept of providing magnetic pawl shift controls, Wear is reduced to a minimum and malfunctioning due to-dirt-and oil debris accumulations, do not retard the effectiveness there o-f. At least, the efficient functioning life of the ratchet is extended and more dependable operation over a longer period is attained.

One object of the present invention is to provide an improved ratchet pawl shifting device for wrenches and the like.

vAnother object is to provide an improved magnetic ratchet pawl shift mechanism that reduces wear and extends the normal eflicient operating life of ratchet wrenches and the like.

Still another object is to provide an improved magnetic pawl control for determining the direction of ratcheting in a clockwise or counterclockwise direction.

A further object is to simplify the construction and operation of wrench ratchet pawls and the like.

A still further object is to provide more efiicient double directional ratchet pawls in wrenches and the like.

Still a further object is to provide an improved magnetic double pawl shifting device wherein wear is reduced to a minimum and the requirement for lubrication is negligible so that dirt and oil debris will not accumulate toimpair the operation of the ratcheting mechanism.

Other objects and advantages will appear from the following description of an illustrated preferred embodiment of the invention.

FIGURE 1 is a perspective view of a ratchet wrench of the type to which magnetically controlled directional pawls may be embodied in accordance with the teachings of the present invention.

FIGURE 2 is a sectional view in elevation taken transversely through the pawl mechanism and lever control of FIGURE 1. I

FIGURE 3 is a fragmentary perspective view of the magnetically controlled directional pawl mechanism illustrated in FIGURE 2.

FIGURE 4 is a fragmentary plan View of the pawl and ratchet mechanism viewed with the wrench housing 3,259,157 Patented May 10, 1966 ice magnetically controlled pawl and ratchet mechanism embodying features of the present invention.

The structure selected for illustration is not intended to serve as a limitation upon the scope or teachings of the invention, but is merely illustrative thereof. There may be considerable variations and adaptations of all or part of the teachings depending upon the dictates of commercial practice. The present embodiment comprises an elongated handle member '10 of my suitable shape and proportion to apply a turning movement thereto and to its enlarged head portion usually formed integral therewith to provide a suitable casing 11, in this instance of arcu'ate or cylindrical configuration. The casing 11 is chambered for the reception of ratcheting instrumentalities to be hereinafter described.

The casing 11 has a circular chamber 12 to freely receive a somewhat smaller work engaging member 13 including a drive shaft, ratchet wheel and a pawl as will more specifically appear from the description to follow. The work engaging member 13 has a trunnion 14 extending through the casing bottom 16 which confronts a closure plate (not shown) that is press-fitted into and corresponds in shape to the casing opening 15 that is slightly smaller to provide for a tight press-fit of the closure plate therewith. The closure plate affords a tight sealed fit with the casing opening 15 and also serves as a bearing for the work engaging member 13 that has a polygonal geometrically shaped stub .shaft 17 to which a wrench socket is detachably associated for retention by a standard spring impelled ball detent that enables differently sized wrench sockets to be used therewith for rotation intermittently through the manually applied turning moment on the wrench handle member 10. This enables variously sized nuts or other fasteners to be tightened and loosened through a ratcheting action as will presently appear.

In order to ratchet the fastener for a tightening or loosening operation, the work engaging member 13 is provided with a ratchet wheel 18 having a series of uniformly spaced ratchet teeth 19 on the periphery thereof confined within the casing chamber 12 (FIGURE 4) to cooperate with a pawl 20. The pawl 20 is, in this instance,

circularly shaped to provide opposed double teeth 21-22 on eachspaced point of the pawl 20 that is, for the most part, of circular configuration interrupted along a short arc to present the opposed teeth 21-22 and to fit into the bottom of the pear-shaped casing opening 15 having an enlarged portion thereof of generally circular shape. The opposed pawl teeth 21-22 on each end of the circular pawl body 20, are adapted to engage the ratchet teeth 19 when rot-atively shifted to one or the other of two extreme positions, namely the extreme clockwise or counterclockwise positions when one or the other of the teeth 21-22 mesh with the ratchet wheel teeth 19 to determine the direction of ratcheting for either tightening or loosening the fasteners as the case may be and the operation requires.

The rotary displacement of the pawl 20 is effected about its axial projecting pin mount 23 journalled, in this instance, in the casing closure plate press-fitted into the casing opening 15. The pawl 20 has two cylindrical magnets 24-25 press-fitted into brass or other non-mag: netic sleeves 26-27 which, in turn, are press-fitted into recesses 28-29 provided in the body of the pawl 20 to present a north and south end pole, respectively, to cooperate with opposite magnetic poles on a pawl position control to be presently described. The pawl 20 is magnetically actuated to oscillate about its pin 23 to cause pawl teeth 21 or 22 to engage the pawl teeth 19 for fastening or'lo osening nuts or other fasteners with a ratcheting turning action. The positioning of the pawl 20 is accomplished by means of confronting spaced cylindrical mag- 3 nets 3031 which are opposite in polarity to the magnets 24-25 to establish an effective attractive magnetic force therebetween as will presently appear to shift the pawl 20.

To this end, the magnets 30-31 are mounted in a magnetically shielded body 36 and joined in a magnetic configuration by a bar plate 32 provided with a center pin 33 for journalled connection through the casing bottom 16 for attachment of an externally accessible lever 34 exteriorly mounted to a pivot in a recessed casing wall chamber 35 to provide a flush shifting device that will not obstruct the ratcheting action in close quarters. It is through the exteriorly accessible lever 34 that the double toothed pawl 2%) is actuated and positioned magnetically without any drag or wear between the pawl 20 and the actuator 33-34. As shown, the actuator magnets 3041 are preferably though not essentially mounted in the body member 36 which could be provided with a projecting nib or fulcrum point 37 cooperating with a minute recess axially indented within the pawl mounting pin 23 to pivot relative thereto with minimum friction. Thus, there is no physical connection between the pawl body 20 and the directional shifting mechanism 3344-36 so that lubrication and the accumulation of dirt and oil debris is not a factor that ultimately impairs the operation of the usual type of ratchet mechanisms, the latter involving mechanical springs to maintain the :pawl teeth in operative engagement with the ratchet teeth.

In the modified embodiment illustrated in FIGURE 5, the pawl 20' consists of angular arms having a pin mount 23' at their juncture to present pawl teeth 21-22'. Magnets 2425 are mounted in the free pawl tooth ends of the pawl arms 20'20' to cooperate with a bar magnet 30' presenting opposite poles relative to the pawl arm magnets 24-25'. 'A pin 33' pivotally mounts the bar magnet 30 to actuate the pawl 20' so that teeth 21' or 22' engage the ratchet wheel teeth 19'. Other structural arrangements can be used to accomplish the same concept and principle of operation for positioning the pawl teeth relative to the ratchet teeth to intermittently tighten or loosen fasteners as required. The on-oif position of the pawl shifting device may be inscribed on the casing bottom 16 near the lever 34 so that the user will not be confused or entail any delay in determining the direction desired for any particular job.

It will be apparent from the foregoing description that the pawl mechanism whether or not single or double, is magnetically controlled as to positioning without any mechanical connection between the position pawl shifter and the pawl or |pawls themselves so that wear is negligible and the accumulation of dirt, oil, grease or other debris will not interfere with the functioning therebetween. Friction between the pawl shifter and the pawls is eliminated, and each of these elements is free from the other as to any physical connection. Each of the elements, namely the pawls and the pawl shifter are physically mounted in the housing independently of each other and without any physical engagement or attachment therebetween. This prolongs the life and operating action of the ratchet mechanism and insures dependable operation over an extended peniod.

While I have illustrated and described a preferred embodiment of the invention, it must be understood that the invention is capable of considerable variation and modification without departing from the spirit of the invention. 1, therefore, do not wish to be limited to the precise details of constructi n l forth, but desire to 4 avail ourselves of such variations and modifications as come within the scope of the appended claims.


-1. A ratchet mechanism comprising a handle member, a casing formed on the end of said handle member, a work engaging member journalled for rotation in said casing, a ratchet wheel on said work engaging member within the confines of said casing, a pawl journalled in said casing so that one or the other of said pawl teeth mesh with said ratchet teeth to intermittently tighten or loosen fasteners when in operative registry with said work engaging member, a pawl shifting control exteriorly accessible relative to said casing and magnetically connected to said pawl, and magnets mounted in said pawl and shifting control in close spaced proximity within said casing to cause said pawl to follow the shifted position of said shifting control to either extreme position of adjust ment.

2. A ratchet mechanism defined in claim 1 wherein the pawl is pivoted in said casing and the shift control is pivotally mounted to a wall of said casing without a direct mechanical connection between said pawl and said shift control.

3. A ratchet mechanism defined in claim 2 wherein the magnets in said pawl and said shifting control are of opposite polarity.

4. A ratchet mechanism defined in claim 1 wherein the magnets in said pawl and said shifting control are of cylindrical configuration and mounted in aligned close spaced proximity to present magnetic poles of opposite polarity.

5. A ratchet mechanism defined in claim 4 wherein the cylindrical magnets are press-fitted into non-magnetizable sleeves to confine the lines of magnetic flux to provide more effective attraction and repulsion between said aligned magnets.

6. A ratchet mechanism defined in claim 3 wherein the :pawl and shifting control are journalled in opposite walls of the casing.

7. A ratchet mechanism defined in claim 2 wherein the pawl is multiple toothed to enable opposite directional ratcheting.

8. A ratchet mechanism for wrenches and the like comprising a casing, means for manually oscillating said casing, a work engaging member journalled for rotation in said casing and projecting therefrom, a ratcheting mechanism in said casing, pawl means for cooperating with said ratcheting mechanism to intermittently turn said work engaging member in one direction or an opposite direction responsive to oscillating said casing, pawl shifting means mounted in said casing in spaced relation to said pawl means without any direct physical connection the-rebetween, and magnetic means on said shifting and pawl means to render said pawl means operatively responsive to said shift means to control the directional ratcheting of said work engaging member.

References Cited by the Examiner UNITED STATES PATENTS 2,750,828 6/ 1956 Wendlin g 8'1-125 FOREIGN PATENTS 61,663 12/1954 France.

WILLIAM FELDMAN, Primary Examiner.

JAMES L. JONES, JR., Examiner.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2750828 *Dec 14, 1953Jun 19, 1956 Le roy j
FR61663E * Title not available
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US6868759Aug 19, 2003Mar 22, 2005Easco Hand Tools Inc.Reversible ratcheting tool
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US7178429Dec 12, 2002Feb 20, 2007Yen-Wen LinEasy-to-assemble ratcheting tool
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US20040016322 *Jul 17, 2003Jan 29, 2004Bobby HuReversible ratcheting tool with a smaller head and improved driving torque
US20040035257 *Aug 19, 2003Feb 26, 2004Hsien-Chung Tuan-MuReversible ratcheting tool
US20040055422 *Dec 12, 2002Mar 25, 2004Yen-Wen LinEasy-to-assemble ratcheting tool
US20040055423 *Sep 25, 2003Mar 25, 2004Bobby HuReversible ratcheting tool with a smaller head and improved driving torque
US20040093995 *Jul 22, 2003May 20, 2004Bobby HuRatcheting wrench with quick tightening/loosening functions and fine adjusting functions
US20040139823 *Jan 5, 2004Jul 22, 2004Bobby HuBiasing arrangement for a pawl of a reversible ratchet-type wrench
US20050145076 *Mar 7, 2005Jul 7, 2005Easco Hand Tools, Inc.Reversible ratcheting tool
US20050166719 *Feb 2, 2004Aug 4, 2005Terence ChenWrench
US20050229751 *Jul 6, 2005Oct 20, 2005Bobby HuRatcheting wrench with quick tightening/loosening functions and fine adjusting functions
US20060101952 *Nov 16, 2004May 18, 2006Lee Chang CPawl mechanism of a ratchet wrench
USRE43286Nov 21, 2002Apr 3, 2012Bobby HuRatchet wheel with asymmetric arcuate concave teeth or non-arcuate concave teeth ratcheting tools with such ratchet wheel and combination of such ratchet wheel and a pawl
EP0798083A1 *Mar 28, 1996Oct 1, 1997Chang Chuan LeeReversible ratchet wrench and reversible ratchet mechanism thereof
WO2016161448A1 *Apr 4, 2016Oct 6, 2016Wheelfloat, Inc.Ratchet mechanism
U.S. Classification81/63, 74/157
International ClassificationB25B13/46
Cooperative ClassificationB25B13/465, B25B13/463
European ClassificationB25B13/46B1C, B25B13/46B1B