US1363274A - Self-adjusting wrench - Google Patents

Description

J. W; SAFFOLD.

SELF ADJUSTING WRENCH.

APPLICATION FILED NOV. soqsn 1,363,274. Patented Dec. 28,1920.

2 Shins-SHEET J. W. SAFFOLD.

SELF ADJUSTING WRENCH.

APPLICATION FILED NOV. 30, 1912.

1 3 3 274 Patented Dec. 28, 1920.

2 SHEETS-SHEET 2- II il l lLllli F l lilll I/VJ/ENTOR W114 ITE STATES PATENT OFFICE.

JAMES WEBB SAFFOLID, 0F CLEVELAND, OHIO; ASSIGNOR, BY MESNE ASSIGNMENTS, T0 VICTOR MANUFACTURING COMPANY, OF DAYTON, OHIO.

SELF-ADJUSTING WRENCH.

Specification of Letters Patent. Patented Dec. 28, 1920.

Application filed November 30, 1917. Serial No. 204,498.

To all whom it may concern:

Be it known that I, JAMES l/VEBB SArroLD, a citizen of the United States, residing at Cleveland, in the county of ()uyahoga and State of Ohio, have invented certain new and useful Improvements in Self-Adjusting Wrenches, of which the following is a speci fication.

My invention relates to improvements in self-adj usting wrenches, and has for its object the provision of a simple, strong and compact Wrench for standard hexagonal nuts, bolt-heads, and the like, within the limits of its adjustable capacity. This wrench is adapted to be used without incurring the damage or mutilation commonly experienced with many types of wrenches, by reason of the fact that the angles or corners of the nuts become worn or bur-red, either through biting or slippage of the wrench aws.

In the patent to Meredith, No. 651,574, June 12, 1900, there is shown a type of wrench which provides an inclosing jaw member adapted to accommodate hexagonal nuts, and an eccentric circular cam-part designed to grip nuts of various sizes within the jaw. However, I have discovered, after considerable experiment, that in order to meet actual requirements, a wrench of this type demands peculiar design and positloning of the cam-part, to prevent slippage of the nut within the jaw, when it is set up tightly upon its bolt. In a wrench of this type a true circular cam Wlll not meet the requirements, because of its s1ze and slippage. The cam-part must be compact, and its face a curve developed in accordance with the principles I shall explain.

Unless said cam-part is properly proportioned to engage the outer plane face of the nut at a point either equidistant from the angular faces engaged with the aw member or within or back of a bisecting plane, the forcible tightening of the nut to set it up completely, will cause the cam-part to slip upon the nut, ultimately wear its corners or angles, and defeat any adequate tlghtening of said nut. Accordingly, I have arranged properly to position and design the same face, so that it invariably will engage a nut of suitable size, and permit it to be tightened.

My improvenents may be best explained by making reference to the accompanying drawings, Where1n:--

Figure 1 IS a view of the jaw member and a portion of the combined handle and cam- [wrench as equipped with two sizes of jaw members.

F ig. 3 is a side view thereof, and

Fig. 4 is a side view of the jaw member on a larger scale.

Throughout the figures of the drawings, I have employed the same character of reference to indicate similar parts.

The wrench of my invention comprises but two parts; the inclosing jaw member suitably shaped to receive various sizes of hexagonal nuts, and a handle pivoted thereto with its integral cam-part adapted to grip the nuts within the jaw as the handle is actuated. Referring to Fig. 1, a jaw member j, shaped in its lower portion to accoming sides forming an angle of as deve loped, or angles of 120 with the transverse portion 7" connecting said sides. A handle it is shown both in engaging or operative position, and in disengaging position (by dotted lines) of which the extension is broken away. A pivot p unites the handle with said jaw member, while an eccentrically positioned cam-part 7c is formed intemodate hexagonal nuts, 71. 6. with conver grally with the handle. A stop or abutment s is provided opposite said cam.

\Vithin the jaw I have shown some seven difi'erent outlines of standard nuts in the respective positions which they would occupy or assume in use. Themedian line m-mt bisects said jaw member and nuts,

and is supplied for the purpose of explain-.

ing the manner in which the developed curve of the cam-face is is determined.

The pivot 10 is eccentrically positioned I and is weakened thereby in a corresponding ratchet wrench. Thus the maximum arc is ascertained to conform to a minimum depth of milling, and this arc is subdivided to correspond with the number of nuts to be accommodated in a given jaw-member. Necessarily, the opening in the jaw-member must be sufliciently large to permit the backward movement thereof, upon the largest size of nut.

In preparing the pattern for the handle,

stop and cam, an outline of the jaw member j is first drawn. The line mm is then drawn along the axis of the figure of the jaw member. The points where the line would be intersected by the rearward sides of the respective nutsplaced within the jaw member are then indicated by drawing the lines a to g. A pattern of the handle and stop is then prepared from celluloid or other transparent material; a pattern blank is pivoted on the figure of the jaw member at the point p. The pattern blank is then swung on the pivot p until some point within an area of the forward end thereof reaches the intersection of the lines a and mm, and this point is indicated on the pattern blank. The

pattern blank is then swung until a point in said forward end thereof coincides with the intersection of the lines I) and m-m, and this point is indicated upon the pattern blank. This operation is repeated until there is indicated upon said forward end of the pattern blank, the points which coincide with the intersections of the lines 0, (Z, 6, f, and g and the line m-m. The pattern blank is then removed from the figure and the points. indicated thereon connected by a curved line and the forward edge of the pattern blank is then cut off along said line. A handle made from the pattern blank thus prepared will be provided with a cam having its face. so curved that its toe is located farther beyond its heel with respect to a line perpendicular to the longitudinal axis of the handle and intersecting the center of the pivot 29 thereof and said face of the cam having nut engaging points a to g which will engage the rearward sides of the nuts at points in the axis of the jaw member, that is, in line with the axes of the nuts which coincide with the axis of the jaw member.

The wrench of Figs. 2 and 3 comprises a common handle-member h with two terminal jaw'members j shaped to accommodate successive sizes of hexagonal nuts. The cam faces thereof, are plotted or developed in the samemanner as I have described with re- 'spect, to the diagram of Fig. 1; it being necessary in every". case to" determine "the developed curve with great accuracy, so that the successive positions or points of engagement shall be at or upon the pivotal side of a median bisecting plane, but preferably very closely adjacent to said plane. The stops or abutments s serve to turn the jawmembers'reversely upon the nut, as the campart is withdrawn within the diagonally milled portions of the respective jaw-members. These and the handle are suitably hardened.

The pivots preferably are formed of a tough nickle-steel, suitably upset in counter-sunk openings provided in the milled portions of each jaw-member, as shown by dotted lines in the enlarged side elevation, Fig. 4:. j

'1 am not aware of available mathematical formulas for determining the shape of the cam, and preferably developits composite curve through successive and substantially equal sectors, corresponding in number to the different sizes of nuts which are to be ]accommodated in each particular jaw-mem- Having now' described a wrench embodying my invention, and more particularly, the manner of arriving at the properly shaped cam face therefor, I claim asnew, and desire to secure by Letters Patent, the following 1. A self-adjusting wrench comprising a jaw member having sides conforming to hexagonal nuts, a handle pivoted. adjacent its forward end to the rear side of said jaw member at one side of the median line thereof, and a cam carried by the forward end of the handle and having its face so curved that its toe is located forwardly beyond its heel, such face being adapted to positively engage nuts of various sizes at points in the median line of the jaw" member.

2. A self-adjusting wrench comprising a jaw member having sides conforming to hexagonal nuts, a handle pivoted adjacent its forward end to the rear side of said jaw member at one side of tlka median line there of, and a cam carried by the forward end of the handle having its face so curved that its toe is locatedv forwardly beyond its heel, such face being adapted to positively engage nuts of various sizes at their rearward faces and centrally thereof and at points in the median line of the jaw member.

3. A self-adjusting wrench comprising a jaw member having sides conforming to hexagonal nuts and its rear portion provided with a slot, a handle pivoted adjacent its forward end to the rear portion ofthe jaw member within the slot and at one side of the median line of said jaw member, a cam carried by the forward end of the handle having its face so curved that its toe is lo cated forwardly beyond its heel, said face adapted to positively engage nuts of various sizes at points in the median line of the jaw member, and a stop on the handle adapted to engage the wall of said slot at one position of said handle.

4. A self-adjusting wrench comprising an inclosed jaw member having a nut receiving space and the sides thereof conforming to hexagonal nuts, the rear portion of said jaw member having a slot communicating with the nut receiving space and forming a shoulder, a handle pivoted adjacent its forward end to the rear portion of the jaw member within the slot and at one side of the median line of said jaw member, a cam carried by the forward end of the handle having its face so curved that its toe is located forwardly beyond its heel, said face adapted to, positively engage nuts of various slzes, at points in the median line of the ja memher, and a stop on the forward en of the handle adapted to engage the shoulder at one position of the handle.

In testimony whereof I do now affix my signature in the resence of two witnesses. J ES WEBB SAFF OLD. Witnesses:

JOHN F. DELL ALBERT LYNN LAWRENCE.

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