US2602362A

US2602362A - Open socket wrench having oscillatable pawl

Info

Publication number: US2602362A
Application number: US124134A
Authority: US
Inventors: Stanley S Johns
Original assignee: Individual
Current assignee: Individual
Priority date: 1949-10-28
Filing date: 1949-10-28
Publication date: 1952-07-08
Anticipated expiration: 1969-07-08

Description

y 8, 1952 s. s. JOHNS 2,602,362

OPEN SOCKET WRENCH HAVING OSCILLATABLE PAWL.

Filed Oct. 28, 1949 INVENTOR. STANLEY $.JOHNS ATTORNEYS Patented July 8, 1952 OPEN SOCKET WRENCH HAVING OSCILLATABLE PAWL Stanley S. Johns, Baltimore, Md.

Application October 28, 1949, Serial No. 124,134 6 Claims. (01. s1 92) The present invention relates to open socket wrench having oscillata-ble pawl and has for its object and purpose to provide a thin, compact and comparatively inexpensive ratchet wrench applicable to nuts and bolts having square or hexagonal cross-sections.

A further object of the invention is to provide a ratchet wrench which will be eilicient in operation and of a rugged construction well adapted to the character of the 'work'it is called upon to perform incident to the tightening of nuts and bolts and the dislodging of the same from tightened positions.

An important feature of this invention resides in the provision of a spring pressed pawl, which has a trunnion portion rockably fitted in a bore in the wrench body and has a shank portion adapted to project into an arcuate nut-receiving space in the wrenchjbody, the shank portion terminating in a flat nut-contacting face engageable with a flat face of a nut. The nut-contacting face lies out'side of a plane containing the axis of oscillation of the trunnion portion and the center of the nut-receiving space, when a stop on the wrench body is engaged by the pawl to arrest the pawl at the time when the nut-contacting face is in planar contact with the nut.

With the foregoing and other objects in view, the invention will bev more fully described hereinafter, and will be more particularly pointed out in the claims appended hereto.

In the drawings, wherein the symbols refer to like or corresponding parts throughout the several views,

Figure l is a perspective view of one form of socketless ratchet Wrench constructed in accordance with the present invention and shown over a bolt head indicating the manner of initial application.

Figure 2 is a fragmentary top plan view, with parts broken away and parts shown in section, illustrating the position of the parts on the tightening stroke of the wrench which is indicated by the arrow.

Figure 3 is a similar view illustrating the backing-oif stroke of the wrench.

Figure 4 is a fragmentary bottom plan view of the Wrench shown as reversed in position for operating upon a loosening stroke.

Figure 5 is a perspective view of the pawl and its trunnion.

Figure 6 is a fragmentary perspective view showing a modified form of the wrench.

Figure '7 is a fragmentary top plan view, with parts broken away and parts shown in section, of the form of wrench shown in Figure 6 illustrating the backing-off stroke of the wrench.

Figure 8 is a similar view illustrating the tight ening stroke of this wrench.

Figure 9 is a bottom plan View of this wrench reversed in position and illustrating the loosening stroke of the same, and

Figure 10 is a perspective View of a form of pawl employed in this modified form of wrench.

Referring more particularly to the drawings, the Wrench body comprises a frame or handle l5 and a head Hi. The head 16 has a part-circular inner wall H, which is preferably greater than a semicircle, and which defines a bolt head or nut receiving space being open at one side as indicated at It.

-A pawl l9, which is of rectangular shape and having a substantially squared planar end surface for engaging the side face of a nut, is carried by the head or handle and is provided with a trunnion 20 on which the pawl may rock. The trunnion is rotatably mounted in a bore 2| in the head or handle, which bore is somewhat greater than a semicircle in order to prevent the escape of the trunnion out through the peripherally open side of such bore 2|. The bore 2| is freely opened through top and bottom faces of the wrench body. In fact the order of assembly is to introduce the trunnion axially into the bore 2!. A stop 22 onthe wrench body is positioned to engage the inner side of the pawl [9 to limit its inwardly swinging or hinging movement. A shoulder 23 between the pawl I 9 and its trunnion 20 at the outer side of the same is designed to engage a stop 25 formed. at the other side of the peripheral gap of the bore 2!. The pawl l9 may rock back and forth between the stops Hand 24 on the axis of the trunnion 20 which is normal to the planes of the upper and lower faces of the wrench body. The pawl l9 extends from the integral trunnion portion 20 in an off-center position relative to the center or pivoting axis of the trunnion, as best seen in Figure 5. A notch 25 in the trunnion 20 receives a pin 26"which is mounted to reciprocate in a hole 21 in the wrench body. A coil or other spring 28 also mounted in the hole behind the pin 25 loads the pin with a spring bias yieldingly urging the pawl [9 against the stop 22. This is due to the fact that the pin 26 engages an end wall 30 of the notch 25 which is eccentric tothe trunnion 20 on the side opposite the stop 22.' The side wall 3! of the notch 25 is adapted to snugly engage the side of the pin 26 when the pawl is in its normal position against the stop 22 as shown in Figure 2. This constitutes a further stop limiting pawl movement toward initial position. As shown in Figures 2 and 3 the pin 26 is positioned across the dividing line between the bore 2| and the Wrench body so that it performs the second function with the notch 25 of retaining the trunnion 20 in the bore 2| and preventing the escape of the pawl from the wrench body. The load of the spring 28 is controlled by a screw plug 29 which incidentally closes the outer end of the hole 21 after the pin 26 and spring 28 have been introduced into the same.

In operation, the wrench is applied to a nut or bolt head 32 as indicated in Figure 1 in which the open space in the head of the wrench is poised above the nut or bolt head 32 before lowering such head upon the bolt head or nut 32 to cause the same to be enveloped by the head in the manner indicated in Figures 2 and 3. In thus applying the wrench to the nut or bolt the latter is not only received into the internal space of the nut head but one flat side of the nut or bolt head 32 is presented against the outer free end, or planar surface, of the pawl III which pro jects into the circle of the wall I! at the open side l8. This condition is shown in Figure 2 in which the edges or corner portions between facets of the nut or bolt head 32 engage with the wall I! so that the nut-or bolt head may be maintained by the wrench head l6 up against the pawl I9. By rotating the wrench body in the direction of the arrow shown in Figure 2 the nut or bolt may be tightened because the rotation has a tendency to keep the pawl I9 against the stop 22 and thus the nut or bolt head will be entrained to rotate with the rotary movement of the wrench. After an appropriate angular stroke has been made, the

stroke is reversed in rotation as indicated in Figure 3 in which event the high point or corner of the nut or bolt head 32 will force the pawl 19 backwardly, compressing the spring 28 and possibly moving the pawl to a position where its shoulder 23 approaches or actually engages the outer stop 24. In any event the pawl I9 will have sufllcient freedom of movement due to its offcenter position relative to the axis of the trunnion to escape past such high point or corner so that the outer end of the pawl I9 may be brought into engagement with an adjacent straight face of the nut or bolt head 32 whereby the clockwise movement of Figure 2 may be repeated to advance the nut or bolt head through a subsequent turning tightening movement. After the pawl has passed the high point or corner the coil spring 28 will re-assert itself and through the pin 26 restore the pawl I'9 against the stop 22. By rocking the wrench back and forth in a well understood manner the nut or bolt 32 may be rotated step by step toward a tightening condition.

As seen in Figures 2 and 4 of the drawing, the outer or free end of the extended portion of the pawl is cut at an angle slightly less than 90 in relation to a line passing through the axis of rotation of the integral trunnion and the center of the nut receiving space ll. Thus, the outer or nut engaging end of the pawl is not cut perpendicular to the longitudinal axis of the rectangular extended portion of the pawl but is cut. at an angle of less than 90 to provide greater rotary movement of the nut or bolt in a loosen-- ing sense or direction; and the clockwise rotation of the wrench will simply cause the pawl I9 to click over the high point or corner of the nut or bolt head without entraining the latter to move with the wrench.

It will be noted, with respect to Figures 2, 4 and 8 of the drawings, that the flat nut contacting face on the free end of the shank portion of the pawl is disposed outside of a plane, which passes through the axis of oscillation of the trunnion portion 20 and the center of the nutreceiving space. The nut-contacting face lies outside of the plane, the outside meaning to the side of the plane in which the pawl portion swings, as seen in Figures 3 and '7. The shank portion swings away from the plane, as the pawl swings towards the stop 24 in the clockwise rotation of the wrench. As seen in the drawings, the plane also contains the planar stop wall but, such form of stop is not critical, since any stop arrangement can be used, such as a stop carried by the trunnion portion. The construction and characteristics of the stop elements are not critical except that such stop elements must act to arrest inward motion of the pawl relative to the nut-receiving space or the above defined plane at a point which will prevent the innermost edge of the nut-contacting face from passing inwardly or over the plane. Thus, the nut-contacting face of the pawl must not extend inwardly. of the plane containing the axis of rotation of the trunnion portion and the center of the nut-receiving space of the wrench body.

Referring more particularly to the second form of the invention shown in Figures 6 to 10 inclusive, all parts are substantially the same and are similarly referenced with the following diiTerences. The wrench head I6 has a completely closed wall Il In other words Figure 1 shows an open end style of wrench and Figure Gshows, a closed end type somewhat along the lines of a conventional box wrench.

Inasmuch asthere is no open end wall such as 24 in Figure 1, the shoulder 23 of the pawl I9 is omitted and the outer Wall l9 merges from the same plane throughout into the rounded adjacent peripheral wall of the trunnion 20*. This wall I9 is adapted to engage against a diagonal wall 33 in the wrench body spaced from the stop 22 to afford a space wider than the pawl II! in which the pawl IS! may have latitude to move back and forth.

Although I have disclosed herein the best. form of the invention known to me at this time, I reserve the right to all suchmodifications and changes as may come within the scope of the following claims.

What I claim is:

1. A wrench for ratcheting on a nut, said wrench comprising a wrench body having an arcuate nut-receiving space, and a spring pressed pawl rockably carried by the wrench body and comprising a shank portion and a partially cylindrical trunnion portion, said trunnion portion being fitted in a complementary partially cylindrical bore in said wrench body so as to be oscillatable about the axis of the bore, said shank portion having a fiat nut-contacting face projecting into said arcuate nut-receiving space to engage a fiat face of a nut, the peripheral wall of said partially cylindrical bore being spaced from said arcuate nut-receiving space, a stop on the wrench body engaged by the pawl to arrest the pawl when the fiat nut-contacting face is in planar contact with the flat face of the nut, said nut-contacting face when said pawl is arrested by the stop lying outside of a plane containing the axis of oscillation of said trunnion portion and the center of said arcuate nut-receiving space, said arcuate nut-receiving space being of such dimensions that the wrench body will contact at least those corners of the nut lying opposite the fiat face of the nut so as tomaintain the nut against the pawl.

2. The combination of claim 1, wherein means is provided to retain the trunnion portion in the bore while permitting its oscillatory movement, said last means including a pin positioned across the dividing line lbetween the bore and wrench body and entering a notch in the trunnion portion larger than the pin.

3. The combination of claim 2, wherein the spring pressed pawl is provided with a biasing means including a spring acting directly upon said pin to exert a potential rotational movement on the trunnion portion in a direction to shift the shank portion against the stop wall.

4. The combination of claim 1, wherein means is provided for biasing the pawl portion to one side of the nut-receiving space and means is provided for retaining the trunnion portion in the bore while permitting its oscillatory movement therein, said last two means being combined in a single structure including a spring projected pin extending across the joint between the wrench body and the trunnion and exertin thrust against an end wall of an eccentric notch in the trunnion portion, said notch also having a side wall for engaging the side of the pin when the pin is in projected position.

5. The combination of claim 1, wherein the nutreceiving space is open at one side adjacent the pawl.

6. The combination of claim 1, wherein the nut-receiving space is boxed in on all sides.

STANLEY s. JOHNS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS