US2725772A

US2725772A - Single pivoted pawl reversible ratchet wrench

Info

Publication number: US2725772A
Application number: US436072A
Authority: US
Inventors: Arthur P Stone
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-06-11
Filing date: 1954-06-11
Publication date: 1955-12-06
Anticipated expiration: 1972-12-06

Description

Dec. 6, 1955 A. P. STONE SINGLE PIVOTED PAWL REVERSIBLE RATCHET WRENCH Filed June 11, 1954 INVENTOR. ARTHUR P. STONE ATTORNEY nited States Patent ()fiice 2,725,772 Patented Dec. 6, 1955 SENGLE PIVOTED PAWL REVERSIBLE RATCHET WRENCH Arthur P. Stone, Akron, Ohio Application June 11, 1954, Serial No. 436,072 Claims. (CI. 81-63) This invention relates to a reversible ratchet wrench.

One object of the invention is to provide a simple reversible ratchet wrench, having a minimum of parts, and yet which is relatively strong and durable.

Another object of the invention is to provide a ratchet wrench wherein the ratchet mechanism is positive in action, that is, having no friction rollers to slip or cause I accidental reversing, and in which there are no delicate pawls or similar small parts likely to break or get out of order.

Another object of the invention is to provide a ratchet wrench wherein only a very slight relative movement of interengageable tooth parts is required to engage or diengage the same for changing the direction of operation of the wrench.

Still another object of the invention is to provide a ratchet wrench of the character described wherein the parts mainly may be made by means of automatic machin ing methods, no drop forgings or cold drawn sections being necessary.

Other objects of the invention will be manifest from the following brief description and the accompanying drawings.

Of the accompanying drawings:

Figure 1 is a top plan view of a ratchet wrench embodying the features of the invention.

Figure 2 is a side or edge view of the wrench shown in Figure 1.

Figure 3 is a bottom view of the same.

Figure 4 is an enlarged longitudinal cross-section of the wrench, partly broken away, and taken substantially on the line 44 of Figure 2.

Figure 5 is an enlarged transverse cross-section, taken substantially on the line 55 of Figure 1.

Figure 6 is a view similar to Figure 4, modified form of ratchet wrench.

Figure 7 is a front edge view, partly broken away, of the wrench shown in Figure 6.

Referring particularly to Figures 1 to 5 of the drawings, there is illustrated a reversing type ratchet wrench embodying the features of the invention, including a head 9 having means 10 incorporated therein for turning a wrench socket or other work-turning tool (not shown), and an elongated handle 11 pivoted to said head.

As best shown in Figures 4 and 5, the head 9 has a cylindrical bore 12 extending to substantial depth from a fiat top side thereof, said bore having an axis normal to a general horizontal plane of the head. A shank 13 is rotatably received in the bore 12 and has an inwardly presented shoulder 14 in seating relation against a seat 15a defined by a reduced opening 12a in the head, through which the shank is extended. The shank is retained in said seating relation by a wire spring retaining ring 16 yieldingly clamped in a groove 16a in the shank at the underside of the head 9. For turning a wrench socket of known type, a squared extension 17 of the shank, at the underside of the wrench, is provided with a spring-pressed ball detent 18.

illustrating a A length 19 of the shank within the bore 12 is cut, knurled or otherwise provided with a plurality of circumferentially spaced V-shaped teeth, a substantial peripheral portion 19a of which may be exposed longitudinally inwardly within a space 20 in said general horizontal plane of the head 9, as defined by spaced

flat bifurcations

21, 21 which are integral with said head. The handle 11 is pivoted on a pin 22 suitably connected between the bifurcations, to have an received within the space 20 and extending longitudinally outwardly toward the shank 13. The outer end of this handle extension is centrally recessed at 24 to define laterally oppositely disposed toothed projections or

shoulders

25 and 26 which, by relatively slight pivotal movement of handle 11 on the pin 22, are selectively complementally engageable with the aforementioned exposed toothed portion 19:: of the shank, the points of such complemental engagement being at one side or other of the longitudinal centerline of the wrench head and relatively close thereto, as best seen in Figure 4.

For releasably and resiliently holding the handle extension in either of said tooth engaging positions, indexing means 28 may be provided at a point intermediate shank 13 and pivot pin 22. Said indexing means may comprise a stem 29 suitably rotatably mounted between the bifurcations 21 of the wrench head, the portion 30 of the stem within space 26 having a rounded end of a spring-pressed detent 31 protruding from the same against an inside cam surface 32 defined by an opening in the handle extension through which opening the indexing stem 29 is freely received. The handle extension is held in each tooth-engaging position by yielding engagement of detent 31 in one of two

recessed portions

33 and 34 in the cam surface 32, as shown in Figures 4 and 5, wherein the detent is adapted yieldingly to retain the toothed shoulder 25 in positive multiple toothed engagement with toothed shank portion 19, for counterclockwiserotation of the shank and work turned thereby, upon corresponding movement of the handle 11 as indicated by an arrow in Figure 4. On the other hand, while the shank is held fixed by the work, the handle 11 and wrench head 9 may be moved in unison in the opposite or forward direction because the yielding detent 31 will allow the toothed shoulder to click over the toothed portion of the shank. A knob 35' on stem 22 is manually engageable to reverse the action of the wrench by rotating stem 29 to position the detent 31 in cam recess 33, thereby to urge shoulder portion 26 into toothed engagement with the shank 13 at the other side of the Wrench centerline.

In operation or use of the wrench shown in Figures 1 to 5, as for loosening a nut on a bolt assembly, a requisite wrench socket (not shown) attached to the squared portion 13a of wrenchshank 13, is engaged with the work in known manner, the knob 35 of indexing means 28 being turned yieldingly to engage detent 31 in stop position in cam recess 34 (see Figures 4 and 5). Thus, the spring pressure on detent 31 will pivot the handle 9 and extension 23, on pin 22 relatively of wrench head 9, in counterclockwise direction thereby to engage the toothed shoulder 25 of the handle extension with the toothed portion 191: of shank 19. By continued manual movement of; handle 9 the work may be turned in counterclockwise direction, in which case it will be noted that said toothed engage ment will be positive because the area of complemental engagement of the toothed the centerline of the tool, or in other words, a centerline between shank 13 and pivot pin 22. As previous ly stated, however, the spring-pressed detent 31 will per mit reverse operation of handle 11 and head 9 while the shank is held by the work, by reason of the toothed shoulder portion 25 being free to'click past the teeth integral extension 23 of the handle parts issubstantially close to on the shank. By alternately operating the handle 11 i in opposite directions, therefore, the toothed parts will be alternately engaged and disengaged for the purpose of turning the work in counterclockwise direction only. In a similar manner the wrench may be reversely operated, as for tightening a nut (not shown), upon turning the indexing knob 35 to. position detent 31 in cam recess 33, to engage the toothed shoulder 26 with the toothed portion 19a of the shank at the opposite side of the centerline of the tool.

In Figures 6 and 7 there is illustrated a modified form of ratchet wrench which is substantially like the wrench shown in Figures 1 to 5, except that the head 9 and a bifurcated extension thereof are formed of two flat.

plates

36 and 37 fixed in spaced apart relation by means. of longitudinally spaced

spacers

38 and 39 on opposite sides of the indexing means 23, longitudinally of the wrench. Like parts, therefore, are given like numerals unless otherwise noted. Spacer 33 serves as the pivot 22 for handle 11, and handle extension 23 is provided with an opening 40 therethrough receiving the spacer 39 in a manner which permits requisite free swinging movement of the handle and extension for the purposes previously described. The shank 13 is formed to have toothed portion 1% thereof rotatably received between the spaced plates 37, as best shown in Figure 7.

In both forms of the invention the ratcheting principle is the same. In each instance, for example, the pivotal connection 22 between the handle 11 and the head 9 is a substantial distance away from the axis of rotation of the shank 13, whereby the opposite or reversed tooth-engaging positions of the handle extension 23 with shank 13 may be accomplished with a minimum of movement of the handle 11, namely a total of three or four degrees. Also, the indexing mechanism 28 is substantially closer to the pivotal connection 22 than to the shank 13, so as to gain optimum pressure of the detent 31 yieldingly holding the handle extension 23 in given positive tooth-engaging relation.

The improved ratchet wrench, in either form thereof, is adapted to be economically manufactured in large scale production, and in a very wide range of sizes.

Other modifications of the invention may be resorted to without departing from the spirit thereof or from the scope of the appended claims.

What is claimed is:

l. A reversible ratchet wrench, comprising a head, a work-turning shank rotatably mounted in said head and having an outwardly presented work-turning part, said head having an integral bifurcated part, a portion of said shank within the head having peripherally spaced teeth, the bifurcations of said part defining a space therebetween in a plane substantially at right angles to the axis of said shank and open to a substantial area of the toothed portion of said shank, a handle pivotally connected on said bifurcated part and having an inward extension in said space, said extension having spaced toothed portions selectively engageable with the teeth on said shank by pivotal movement of said handle and extension on said bifurcated part, said handle extension having an opening therethrough defining a cam surface having spaced recessed portions, a member rotatably mounted on said bifurcated part and having a portion loosely received in said opening, said member portion having a spring-pressed detent yieldingly engaging in one or other of said cam recessed portions for holding said handle and extension in either of said tooth-engaging positions, and manually operable turning means on said member for operating the same to holding positions thereof.

2. A reversible ratchet wrench, comprising a head, a work-turning shank rotatably mounted in said head and having an outwardly presented work-turning part, said head having an integral bifurcated part, a portion of said shank within the head having peripherally spaced teeth, the bifurcations of said part defining a space therebetween in, a, plane substantially at right angles to the axis of said shank and open to a substantial area of the toothed portion of said shank, a handle pivotally connected on said bifurcated part and having an inward extension in said space, said extension having spaced toothed portions selectively engageable with the teeth on said shank by pivotal movement of said handle and extension on said bifurcated part, and releasable holding means for holding said handle and extension in either of said tooth engaging positions, said head and said bifurcations thereof including superposed plates having spaced pins fixedly holding the same in spaced apart relation, one said pin constituting the pivotal con nection for said handle on said bifurcated part, said handle extension having an opening therethrough freely receiving the other said pin to permit said pivotal movement of the handle.

3. A reversible ratchet wrench, comprising a head, a work-turning shank rotatably mounted in said head and having an outwardly presented work-turning part, said head having an integral bifurcated part, a portion of said shank within the head having peripherally spaced teeth, the bifurcations of said part defining a space therebetween in a plane substantially at right angles to the axis of said shank and open to a substantial area of the toothed portion of said shank, a handle pivotally connected on said bifurcated part and having an inward extension in said space, said extension having spaced toothed portions selectively engageable with the teeth on said shank by pivotal movement of said handle and extension on said bifurcated part, and releasable holding means for holding said handle and extension in either of said tooth engaging positions, said holding means including a spring-pressed detent allowing only unidirectional rotation of said shank relatively of said head, said member and associated holding parts thereof being located intermediate said shank and the pivotal connection of said handle, said head and said bifurcations thereof including superposed plates having spaced pins fixedly holding the same in spaced apart relation, one said pin constituting the pivotal connection for said handle on said bifurcated part, said handle extension having an opening there through freely receiving the other said pin to permit said pivotal movement of the handle.

4. A reversible ratchet wrench, comprising a head, a work-turning shank rotatably mounted in said head and having an outwardly presented work-turning part, said head having an integral bifurcated part, a portion of said shank within the head having peripherally spaced teeth, the bifurcations of said part defining a space therebetween in a plane substantially at right angles to the axis of said shank and open to a substantial area of the toothed portion of said shank, a handle pivotally connected on said bifurcated part and having an integral inward extension in said space, said extension having spaced toothed portions selectively engageable in opposite directions with the teeth on said shank by pivotal movement of said handle and extension on said bifurcated part, and releasable holding means including a member shiftably mounted on said head and yieldingly interengageable portions being provided on the member and the handle extension for selective interengagement in oppositely biased positions of the handle extension, thereby yieldingly to bias said extension with one or other of said spaced toothed portions thereof engaging the teeth of said shank to prevent rotation of said shank in one corresponding direction and yieldingly to permit rotation of the shank in the opposite direction.

5. A reversible ratchet wrench, comprising a head, a work-turning shank rotatably mounted in said head and having an outwardly presented work-turning part, said head having an integral bifurcated part, a portion of said shank within the head having peripherally spaced teeth, the bifurcations of said part defining a space therebetween in a plane substantially at right angles to the axis of said shank and open to a substantial area of the toothed portion of said shank, a handle pivotally connected on said bifurcated part and having an inward extension in said space, said extension having spaced toothed portions selectively engageable with the teeth on said shank by pivotal movement of said handle and extension on said bifurcated part, and releasable holding means including a member pivotally mounted on said head intermediate said pivotal connection of the handle and said shank and yieldingly interengageable portions being provided on the member and the handle extension for selective interengagement in oppositely biased positions of the handle extension, thereby yieldingly to bias said extension with one or other of said spaced toothed portions thereof engaging the teeth of said shank to prevent rotation of said shank in one corresponding direction and yieldingly to permit rotation of the shank in the opposite direction.

References Cited in the file of this patent UNITED STATES PATENTS 952,436 Miller Mar. 15, 1910 1,451,498 Faitz Apr. 10, 1923 1,957,462 Kress May 8, 1934 2,537,175 Viets Jan. 9, 1951 2,691,910 Greak et al. Oct. 19, 1954 FOREIGN PATENTS 393,243 Great Britain Aug. 24, 1931