US 3742789 A
A wrench for dowel pins and the like formed from bar stock. Longitudinally extending grooves are formed in the external surface of the bar stock so as to communicate with one of its ends, and pieces of key stock are placed in the grooves so as to project from the end of the bar stock for use as tangs. Where the wrench is to be used for applying torque to dowel pins, the bar stock will be provided with an axially extending opening communicating with said one end, and will preferably also include a pair of laterally aligned openings through the walls on opposite sides of the axially extending opening.
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Description (OCR text may contain errors)
United States Patent 11 1 Rusk et al. 1 July 3, 1973 1 WRENCH 2,581,095 1/1952 Godmaire 81/90 R  Inventors: Gerald R. Rusk; Robert E. Koch,
both of Toledo, Ohio Primary Examiner-Othell M. Simpson Assistant Examiner-James G. Smith Att0rneyWilliam P. Hickey  ABSTRACT A wrench for dowel pins and the' like formed from bar stock. Longitudinally extending grooves are formed in the external surface of the bar stock so as to communicate with one of its ends, and pieces of key stock are placed in the grooves so as to project from the end of the bar stock for use as tangs. Where the wrench is to be used for applying torque to dowel pins, the bar stock will be provided with an axially extending opening communicating with said one end, and will preferably also include a pair oflaterally aligned openings through the walls on opposite sides of the axially extending opening.
5 Clairns, 5 Drawing Figures PATEN-TEDJULB I975 ENTOR. 05/! 08687 E. Kac/I ATTOQNEY WRENCH BACKGROUND OF THE INVENTION In one type of mold or core making equipment, one open face box having a cavity therein configured to form one half of the surface of the mold or core is superimposed on the open face of another box having an inside configuration corresponding to the other half of the mold or core. The two open face boxes are called hot boxes and are brought into accurate register when the boxes are assembled, by what are called pin and bushings. The pins project from one of the boxes and extend into receiving bushings in the other box. These boxes are heated to approximately 500F. When the boxes are assembled, sand with a thermosetting binder is put into the cavity between the boxes and the binder hardened to hold the sand in the shape formed by the assembled boxes. The pins and bushings are conventionally provlded with threaded shank portions which are screwed into threaded openings in the respective boxes. The boxes are allowed to cool down when not in use, so that the pins and bushings are alternately heated by the hot boxes and then cooled, and so that the pins and bushings become seized in the hot boxes after a period of time. Threaded pins and bushings are used in still other types of equipment in which the same seizing problem is experienced. These pnns and bushings are threaded into the boxes by specially made dowel pin wrenches.
In the Gerald R. Rusk U.S. Pat. No. 3,354,756 there is provided a teaching of aligned laterally extending openings in an otherwise conventional dowel pin wrench for receiving a drill rod or the like which also extends through an opening in a dowel pin to apply additional torque to the dowel pin. The prior art dowel pin wrench comprises an annular body, opposite segments of one end of which are milled away to provide integral tangs on opposite sides of its central opening for insertion into lateral groves in the top surface of the flange of a dowel pin. It has been found that although the use of the lateral drill rod is capable of applying additional torque to the dowel pin, the tangs on the prior art wrenches shear or deform to such an extent, that most of the load is transferred onto the drill rod to shear off the projecting pin portion of the dowel pnn.
Accordingly, an object of the present inventon is the provision of a new and improved wrench for use with dowel pins, bushings and the like wherein the tangs are formed by pieces of removable hardened stock confined between abutment surfaces on the wrench body.
A further object of the present invention is the provision of a new and improved wrench of the above described type wherein the abutments are formed by iongitudinally extending grooves in the external surfaces of the wrench and which are adapted to receive hardened rod or key stock.
A still further object of the invention is the provision of a new and improved wrench of the above described type wherein the body is made from a section of a polygonal shaped bar having polygonal surfaces of sufficient length that an impact hammer can be used on one end of the wrench body, and a manual actuated wrench can be used on an intermediate portion of the body.
Further objects and advantages of the present inventon will become apparent to those skilled in the art to which the invention relates from the following description of several embodiments described with reference to the accompanying drawings forming a part of this specification.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of an end of a wrench embodying principles of the present invention, and further showing a drill rod positioned for insertion through aligned openings in the wrench;
FIG. 2 is a side elevational view of the wrench and pin shown in FIG. I;
FIG. 3 is an elevational view of the wrench shown in FIGS. 1 & 2 when installed on a dowel pin frozen in a hot box;
FIG. 4 is a side view of a tang of the wrench shown in FIGS. 1 & 3;
FIG. 5 is a side view of the wrench body shown in FIGS. 1 & 3;
DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiment shown in FIGS. 1 through 5 generally comprises a body 10 preferably made from a section of hexagonal bar stock to conveniently provide polygonal shaped wrench receiving surfaces over its full length. The wrench is of the type having longitudinally extending tangs for insertion into corresponding recesses in the end surface of a threaded member. According to the invention, these longitudinally extending tangs are made from commercially available bar, and preferably key stock, positioned between suitable abutment surfaces on the body member-10. In the preferred embodiment these abutment surfaces are formed by longitudinally extending grooves or keyways l4 machined into the external surfaces of the body member 10. The tangs 12 made from key stock the grooves 14, and the ends of the tangs 12 may be reground to continually provide sharpened tang surfaces. The tangs 12 can be retained in any convenient manner since the torque is taken by the abutment surfaces of the keyways 14. In the embodiment shown in FIGS. 1-3, retention is accomplished by individual machine screws 16. These machine screws 16 are fitted into openings positioned along sides of the keyways 14 with the heads of the machine screws 16 tightened down into engagement with the outer edge of the key stock 12.
In those instances where the wrench is to be used to transmit torque to threaded guide pins, the body member 10 will be provided with a longitudinally extending opening 18 in the end surface from which the tangs 12 project. Also, when the wrench is to be used for driving threaded dowel pins, the body member 10 will preferably be provided with diametrically extending lateral openings 20 between its external surfaces and the surfaces of the opening 18 for the reception of a piece of hardened drill rod 22, as explained in the above referred to U.S. Patent.
The wrench shown in FIGS. 1-3 without the aid of the rod 22 is capable of transmitting at least 50 percent more torque than have prior art wrenches having integral tangs. When the pin 22 is used, the wrench is capable of transmitting more than twice the amount of torque which prior art dowel pin wrenches are capable of transmitting.
FIG. 3 of the drawing shows the wrench in driving engagement wth a dowel pin utilizing the rod. The dowel pin is of the type shown in U.S. Pat. No. 3,472,312 and is shown frozen in a sectioned portion 26 of a foundry cope. The wrench is shown locked onto the dowel pin 24 by the rod 22. The rod 22, of course, extends through the openings 20 in the wrench 10, and through an aligned opening in the dowel pin as explained in U. S. Pat. No. 3,472,312. The projecting ends of the tangs 12 are received in corresponding slots 28 in the flange 30 of the dowel pin 24.
It has been found that the greatest torque can be transmitted to a dowel pin by attaching the drive socket of an impact wrench to the end of the body 10 in addition to slipping a open end wrench over the body 10 beneath the socket of the impact wrench. Th impact hammer is started to impose its jarring impact over the top of the uniform torque that is applied manually. The rod 22 in addition to transmitting torque to the dowel pin also prevents the tangs 12 from riding up out of the slots 28 in the flange 30 in the dowel pin. Care must be taken that the clearance between the pin 22 and the openings 20 in the body of the wrench 10 matches the clearance between the tangs 12 and the slots 28 of the dowel pin, so that torque is transmitted uniformly by both media.
The dowel pin wrench shown and described has a combination of features and advantages which have never heretofore existed in a single dowel pin wrench. Not only is the wrench capable of transmitting more torque than has ever heretofore been possible, but it will receive a combination of socket, open end, and impact wrenches for applying this increased torque to the wrench body. This increased torque is transmitted through standard key stock and/or cylindrical pin stock which can be thrown away and replaced at very little expense, or can be reground and reused as deiired. In addition, the dowel pin wrench is made from standard bar stock, and the neessary abutment surfaces are provided thereon with the simpliest of machining operations, so that the new and improved wrench can be pro-' duced at a cost that is considerably less than the prior art dowel pin wrenches. Although the dowel pin wrench has been described as having particular advantages for the driving of dowel pins such as is used in foundries, it will be understood that the wrench is not limited for use therewith and may be used to drive any threaded member having slotted end surface.
In order that the maximum cross section of tang 12 can project from the wrench body 10 and still be supported by the wrench body 10, the groove 14 is stepped as at 32 with the groove portion 34 below the step being milled through the entire thickness of wrench body between the internal opening 18 and the external surface of the body 10. The portion of the groove 14 above the step 32 has sufficient depth to grip the key 12 but there is enough metal in the wrench body between this portion of the groove 14 and opening 18 to prevent opposite sides of the body 10 from spreading apart. The portion 36 of the groove 14 above the step 32 preferably has a depth approximately one half that below the step 32. The key 12 is similarly stepped as at 38.
While the invention has been described in consider able detail, we do not wish to be limited to the particular embodiments shown and described, and it is our intention to cover hereby all novel adaptations, modifications and arrangements thereof which come within the practice of those skilled in the art to which the invention relates.
We claim 1. A dowel pin wrench, comprising: a single piece of bar having a longitudinally extending center axis and lower and upper opposite endgenerally planar surfaces; said piece of bar having an axially extending opening in its lower end suface, a pair of longitudinally extending keyways in the exterior surface of said piece of bar, with said keyways opening into said lower end surface; a piece of key stock in each keyway; clamping means for retaining said pieces in said keyways; a pair of aligned openings extending between the exterior surface of said wrench and said axially extending opening for receiving a work retaining pin; and the exterior surface of said wrench adjacent said upper end having a polygonal shape, and the upper end of said wrench being free of projections that would interfere with the socket 'wrench of a torquing device.
2. The wrench of claim 1 wherein said pieces of key stock are movable longitudinally of said keyways, and said clamping means are constructed and arranged to hold said pieces in various adjusted positions spaced longitudinally of said wrench.
3; The wrench of claim 2 wherein said keyways are stepped with the portion of each keyway adjacent said lower end being deeper than the remaining portion of the keyway, and with the pieces of key stock being similarly stepped for reception in said stepped keyways.
4. The wrench of claim 3 wherein said clamping means are threaded fasteners the heads of which bear against the outer surface of said pieces of key stock and are threaded into said piece of bar.
5. The wrench of claim 4 wherein said piece of bar is a section of hexagonal bar stock.