US2112840A

US2112840A - Method of making wrenches

Info

Publication number: US2112840A
Application number: US20425A
Authority: US
Inventors: Foster A Haist
Original assignee: Williams J H & Co
Current assignee: J H Williams & Co; Williams J H & Co
Priority date: 1935-05-08
Filing date: 1935-05-08
Publication date: 1938-04-05
Anticipated expiration: 1955-04-05

Description

April 5, 1938. I F. HAIST 2,112,840

' METHOD OF MAKING WRENCHES Filed May 8, 1935 Patented Apr. 5, 1938 UNITED ST TES PATENT OFFICE assignments, to J. H. W

illiams & 00., Butfalo, N. Y., a corporation of New York Application 'May 8, 1935, Serial No. 20,425

4 Claims.

solutions thereof are disclosed in detail in they herein patent specification, wherein,--

-In the accompanying figures:

Fig. 1 is a fragmentary side elevation of my improved wrench.

Fig. 2 is a vertical, longitudinal section thereof, taken on line 2--2, Fig. 4.

Figs. 3 and 4 are fragmentary, horizontal sections through said wrench, taken on correspondingly numbered lines of Fig. 2.

Similar characters of reference indicate like parts in the several figures of the drawing.

The present invention has been illustrated as applied to a solid, forged steel, adjustable end wrench of the oblique handle type. The invention, however, is not confined to this particular type of wrench, but may be utilized in any adjustable wrench although most efiectively in an adjustable end wrench in which the head, fixed jaw and handle are formed from one piece of metal.

The wrench here illustrated consists primarily of a single steel forging constituting a head H), a fixed jaw I I and an oblique handle I 2, and having a movable jaw l3 slidably mounted in said head Ill. The medial portion of said head In at a point rearwardly of the fixed jaw II is cut away to form the relatively narrow, longitudinal, vertical, fiat-faced alignment throat l4. Said throat is relatively narrow in a horizontal, transverse direction and opens at its rear end into a vertical guideway l5 which is relatively wide in a horizontal, transverse direction. The rear or inner portion l6 of said vertical guide I5 is semicylindrical in cross section (as seen in Figs. 3.

and 4), while its front or outer portion is rectangular in cross section forming a pair of vertical, longitudinal, fiat side walls I1, I! and a pair of vertical, transverse, fiat abutments l8, l8.

The movable jaw l3 of the wrench is integrally connected on its rear face with a vertical, longitudinal shank 20 which is relatively'narrowin a transverse direction and is rectangular in hori- Y zontal section (see Figs. 3 and 4) and is slidably received within the relatively narrow, fiat-faced, alignment throat M. This shank 20 maintains the movable jaw l3 in transverse alignment at whatever slidable position it may happen to 00- cupy, i. c. said shank 20 in cooperation with said alignment throat I4 keeps the movable jaw l3 at all times in correct vertical register with the fixed jaw ll. Secured integrally to the rear end of said fiat-faced alignment throat I4 is a vertical slide 2|. The latter has the same horizontal cross sectional shape as the vertical guideway l5, being of semi-cylindrical, horizontal cross section at its rear part and of rectangular, horizontal cross section at its front part. Said vertical slide 2i of the movable jaw l3 extends some distance both above and below said movable jaw I 3 for reasons which are well known in the art.

The rear, vertical, semi-cylindrical face of said slide 2| is hobbed or otherwise suitably machined to form a vertical rack 22. The head H! of the wrench is suitably cut away to form the rectangular opening 23 which extends horizontally clear through said head l0. Arranged in said opening 23 is an operating worm gear 24, the spiral gear tooth of which engages the teeth of the rack 22 so that when said worm gear 24 is rotated in the one or other direction, the movable jaw I 3 is moved toward or away from the fixed jaw II as may be desired for adjusting the wrenchto any particular size of nut. The periphery of said worm gear is preferably knurled in the usual manner, as shown, to facilitate the turning of said worm gear manually.

Said worm gear 24 is rotatably mounted on a pin 25 the extreme lower end of which is enlarged and male threaded at 26 while the shank or rest of the pin is of cylindrical shape and is smaller in diameter than the threaded portion 26. The extreme upper portion 21 of the cylindrical shank of said pin is received'within an upper vertical hole 28 situated just above the I rectangular opening 23, while the lower portion 2H of the cylindrical shank of said pin is re- 1 ceived within a lower, vertical hole 28! in axial. alignment with aforesaid hole 28 and situated just below said rectangular opening 23. Said lower vertical hole 28! is employed to guide the tap when tapping the female thread which receives the male thread 26 of the pin 25. By this construction said pin 25 is solidly supported by its upper and lower'cylindrical portions 21, 2' just above and below said rectangular opening 23 thus requiring of the-thread 26 only the duty of pushing the pin 25 up vertically into place and firmly holding it in this position. This point to be manufactured from straight bar stock with no cutting operation other than the screw driver slot 3..

It is desirable to have the fixed and movable jaws ll and l3, respectively, as far apart as possible for any given setting of the worm gear 24 and its companion rack 22, so as to take up whatever slack may be present. One point where this slack occurs (when the permitted manufacturing tolerances are very large) is in the vertical movement of the operating worm gear 24 in its rectangular opening 23. This slack is taken up in an improved manner in the present invention by a conical compression spring II the upper, large end of which bears upwardly against the upper flat face of the opening 23 while its lower, small end is received within and bears resiliently downwardly against the small end of a conical counterbore 32 formed axially in the upper end of the operating worm gear 24. Such a conical counterbore is much less expensive to obtain in large quantity production than the conventional rectangular counterbore and also has the advantage of permitting the use of a relatively long compression spring 3i without mechanically weakening the worm gear 24. This conical arrangement has the further advantageof imposing a greater than usual frictional resistance to turning of the worm gear 24 because of the fact that the fric-- tlonal pressure which is normal to the face of the conical counterbore 32 (and hence is in opposition to the rotation of the worm gear 24) is greater than the vertical thrust of the conical spring 3| The method of manufacture The first operation is the forging of the fixed jaw, wrench head I. and handle l2 from one piece of properly alloyed high carbon steel. In this forging process the rectangular opening 23 is also formed. The wrench is then drilled, as shown in Fig. 3 by the dotted line 33 together with the full line It, the latter forming ultimately the rear or inner end of the guideway l5 of the wrench head ll. Said guideway i5 is then broached with a suitable broacha It is to be particularly noted that, in this, broaching operation, the broach cuts only at the front or outer part of said guideway l5 andisiirmlybraced, while doingthis cutting, by the already formed semi-cylindrical surface It. This broaching results in the formation of the flat side walls ll, I1 and the flat abutments ll, It. The alignment throat I4 is then formed in the usual and well known manner.

The holes 28 and 2" are now drilled, and the latter then used as a guide for tapping the female thread which engages the male thread 26 of the pin '25. The movable jaw l3 with its integral shank 20 and slide 2 l is then slid into place. The

r'nale thread 26 of the pin 28 is then formed by rolling or otherwise and assembled withits companion operating worm gear 24 and conical compression spring Ii.

l'ormaximmnstrengthawrenchofthistype should be rotated in the direction shown by the full line'arrows of Fig. 2. It'must be borne in mind, however, that the wrench will frequently be usedinsuch adirectionastocause thrusts onthe jaws of the type shown .by dotted line arrows. In

, either case it will be noted that the force, to which vention, by the pressing of the flat, vertical, transverse faces of the slide 2| against the flat, vertical. transverse abutments l8, ll. These flat faces and abutments are disposed perpendicularly of the.

. imposed pressure and consequently cannot spread the side walls of the guideway I, as occurs in wrenches of conventional construction, whenever the wrench is subjected to heavy abuse or overloading beyond the elastic limit of the metal. As

a result. this improved form of wrench maintains its original strength and smoothness of operation even if subjected to much abuse or overloading, provided, of course, that the load isnot sumcient- 1y excessive to strain the metal beyond its ultimate strength.

In this connection it is to be noted that even for loads within the elastic limit of the metal, this improved wrench is superior to the conventional wrench in that the slide 2| of the movable jaw i3 is prevented from binding in its guideway i5 because of the fact that any lateral pressure exerted in any lateral direction by said slide is imposed .upon a surface which is perpendicular of said force, whereas in a number of conventional wrenches of this general type longitudinal pressures in a forward or outward direction are imposed upon a surface which is oblique to said pressure, similar to the manner in which a V power transmission belt exerts more pressure than a flat belt.

When an operator is using a wrench of this character, he usually moves the movable jaw I! to a certain position and then successively applies the wrench to the nut, gives the same a partial turn, removes the wrench and returns to its original position and gives said nut another partial turn. In this procedure it is important that the operating worm gear 24 be not moved out of its properly adjusted position. This is effected, in the present invention, by providing a more than usual frictional resistance to the turning of said worm gear by the provision of the conical compression spring 3| in the conical counterbore 32, in this case deliberately obtaining the very V belt type of friction which in the case of the slide 2i was seen to be objectionable. This conical construction also permits of a long spring to give a soft resilient, frictional action and to take up the slack ofthe womb-gear 24 relatively to the wrench head III, and accomplishing these results without mechanically weakening said worm gear 24, as would occur if a counterbore of equivalently large diameter were to extend an equivalent distance cylindricallly into the upper face of said worm gear. 4

In addition to the foregoing, said worm wheel 24 always moves freely on its pin 25 by reason of the fact that any lateral forces to which said worm gear or pin may be subjected are not imposed upon the thread 25 but only upon the cylindrical 2,112,840 j 3 surfaces of the holes 28, 28 l which may be accurately drilled (and even reamed if desired) at relatively little expense. Because of this fact said pin does not become loosened when the wrench is being used, and hence said pin 25 does not become loosened and finally fallout as frequently occurs when the wrenches are subjected to constant vibration, as when being carried in the tool box of an automobile.

I claim as my invention:

1. The method of making a wrench consisting of the forming of a head having a fixed jaw; drilling a hole' in said head perpendicularly of said' fixed jaw; passing a broach into said drilled hole and cutting a fiat abutment on only the front side of said hole; guiding and supporting the rear side of said broach during the broaching operation on therear cylindrical surface of the drilled hole; assembling a movable jaw having a guide which is received within said broached hole' and has a semi-cylindrical rear portion and a flat-faced front portion; and providing means for moving said movable jaw relatively to said head, in a direction parallel to said broached hole.

2. The method of making a wrench consisting of the forming of a 'head having a fixed jaw; drilling a hole in said head perpendicularly of said fixed jaw; passing a broach into said drilled I hole and cutting a pair of flat abutments on only the front side of said hole; guiding and supporting the rear side of said broach during the broaching operation on the rear cylindrical surface of the drilled hole; assembling a movable jaw havinga guide which is received within said broached hole and has a semi-cylindrical rear portion and a dual shouldered front portion; and providing means for moving said movable .jaw, relatively to said head, in a. direction parallel to said broached hole.

3. The method of making a wrench consisting of the forming of a head having a fixed jaw; drilling a hole in said head perpendicularly of said fixed jaw; passing a broachinto said drilled hole and cutting a fiat abutment at a-point located rearwardly of its extreme front portion;-

guiding and supporting the rear side of said broach during the broaching operation on the rear cylindrical surface of the drilled hole; assembling a movable jaw having a guide which is received within said broached hole and has a semi-cylindrical rear portion and'a flat faced front portion; and providing .means for moving said movable jaw, relatively to said head, in a direction-parallel to said broached hole.

4. The method of making a wrench consisting of the forming of a head having a fixed jaw; drilling a hole in saidhead perpendicularly of said fixed jaw; passing a broach into said drilled hole and cutting a pair of'symmetrical flat abutments each at a point located rearwardly of its.

extreme front portion; guiding and supporting the rear side of said broach during the broaching operation on the rear cylindrical surface of the drilled hole; assembling a movable jaw having a guide which is received within said broached hole and has a semi-cylindrical rear portion and a symmetrical dual-shouldered front portion; and providing means for moving saidmovable jaw relatively to said head, in a direction parallelto said broached hole.

FOSTER A. HAIST.