Abstract:
A universal jig/work holding fixture for precision manual reaming of valve bores within a transmission valve body, or other work piece is disclosed. The universal jig/work holding fixture includes a tool holder (i.e. jig) having universal swiveling movement in all axes, which allows precise axial alignment of a reaming tool to the longitudinal axis of a valve bore. The universal jig is contained within a work holding fixture whereon the valve body or other work piece is clamped during the reaming operation. The work holding fixture is constructed to accommodate vertical and lateral adjustment of the tool holder relative to the work holding fixture to permit precise alignment of the reaming tool and provides mechanisms to lock the tool holder and work piece in a desired position. The universal jig/work holding fixture allows a service technician in a transmission shop environment to achieve a precision repair using only manual tools.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Patent Application No. 60/504,467 filed Sep. 17, 2003 entitled Universal Jig/Work Holding Fixture. 
     
    
     BACKGROUND OF INVENTION  
       [0002]     The present invention relates to automatic transmissions for land vehicles and, more particularly, to a universal jig/work holding fixture and reaming method for the repair of worn valve bodies and pumps of FORD, GENERAL MOTORS, and other similar automatic transmissions.  
         [0003]     Automatic transmission systems of the prior art have a hydraulic circuit subsystem which includes at least a hydraulic pump, a valve body having fluid conducting passages or circuits, input and exhaust ports formed within the fluid circuits, and a plurality of spool valves so-called because of their resemblance to sewing-thread type spools. Such spool valves are comprised of generally cylindrical pistons having control diameters or lands formed thereon, which alternately open and close the ports to fluid circuits for regulating the flow and pressure of automatic transmission fluid (hereinafter “ATF”) within the transmission.  
         [0004]     Such spool valves must often be replaced or refurbished during service procedures due to mechanical wear. If wear is extreme the cylindrical bores in the valve body wherein such valves are located must be machined oversize to a close tolerance to accommodate an oversize valve or a replacement valve fitted with a mating sleeve, which is installed in the oversize bore. Providing a leak proof seal between the mating surfaces of the oversize valve and/or sleeve and the valve body to prevent cross-leakage between hydraulic passages which adjoin the replacement valve is critical to salvaging a worn original equipment (hereinafter “OE”) valve body.  
         [0005]     A significant problem is presented to the service technician in obtaining this close tolerance fit in a typical transmission repair shop using only manual tools. Thus, the present invention has been developed to resolve this problem and other shortcomings of the prior art.  
       SUMMARY OF THE INVENTION  
       [0006]     Accordingly, the present invention provides a universal jig/work holding fixture for precision manual reaming of valve bores within an OE valve body or pump, which can be achieved by a service technician in a repair shop environment. This is accomplished with the present jig/holding fixture by axial alignment of a reaming tool, drill, or other cutting tool to the worn OE bore utilizing a tool holder having universal (i.e. swiveling) movement in all axes, which allows precise axial alignment of the tool to the OE valve bore or pump body. The universal jig is integrated within the work holding fixture whereon the valve body or pump is clamped during the reaming operation.  
         [0007]     There has thus been outlined, rather broadly, the important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.  
         [0008]     Other features and technical advantages of the present invention will become apparent from a study of the following description and the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     The novel features of the present invention are set forth in the appended claims. The invention itself, however, as well as other features and advantages thereof will be best understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures, wherein:  
         [0010]      FIG. 1  is a side elevational view of the universal jig/work holding fixture of the present invention;  
         [0011]      FIG. 2  is a top plan view of the bed plate of the present universal jig/work holding fixture;  
         [0012]      FIG. 3 a  is top plan view of the mounting bracket of the present universal jig/work holding fixture;  
         [0013]      FIG. 4  is a top plan view of the jig plate of the universal jig/work holding fixture;  
         [0014]      FIG. 5A  is a cross-sectional view of one embodiment of the tool holder assembly of the universal jig/work holding fixture including a spherical bearing;  
         [0015]      FIG. 5B  is a cross-sectional view of another embodiment of the tool holder assembly of the universal jig/work holding fixture including a two-piece spherical washer;  
         [0016]      FIG. 6  is a plan view of the clamping plate of the present universal jig/work holding fixture;  
         [0017]      FIG. 7  is a side elevational view of the universal jig/work holding fixture illustrating the reaming process being performed on a valve body attached thereto; and  
         [0018]      FIG. 8  is an exploded perspective view of another embodiment of the present universal jig/work holding fixture. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0019]     With further reference to the drawings there is shown therein an embodiment of a universal jig/work holding fixture in accordance with the present invention, indicated generally at  10  and illustrated in  FIG. 1 . To relieve prolixity in this application, the present universal jig/holding fixture  10  will be described primarily for use in the reaming of valve bores within valve body  50  of an automatic transmission. However, it will be understood that the present jig/fixtures  10 ,  10 ′ disclosed herein may also be used for reaming of valves bores within a transmission pump (not shown) or other similar work piece wherein a valve resides.  
         [0020]     The jig/fixture  10  is an assembly of components, namely, a bed plate or bed, indicated generally at  15 , a jig plate, indicated generally at  20 , a clamping plate, indicated generally at  25 , and a universal tool holder assembly, indicated generally at  30 . In the embodiment shown in  FIG. 1 , a mounting bracket  35  secures bed  15  and jig plate  20  in pivoting relation as explained hereinafter in further detail.  
         [0021]     As shown in  FIG. 2 , the bed  15  is a generally rectangular structure having a cutout section  16  formed along its centerline and extending inwardly from a first lateral edge  15   b  thereof. Cutout section  16  provides access for applying cutting fluid during a reaming process wherein the present invention is utilized. The bed  15  includes a flat, machined surface  15   a  whereon valve body  50 , a transmission pump (not shown), or other work piece is secured during the reaming process.  
         [0022]     As seen in  FIG. 3  mounting bracket  35  is an elongated support member, which extends transversely beneath the cutout  16  and along the first lateral edge  15   b  of the bed  15  ( FIG. 2 ). In the embodiment shown, mounting bracket  35  is mechanically attached to bed  15  by fasteners such as machine screws  36  ( FIG. 1 ), which are installed within through holes  40  ( FIG. 3 ) formed in the bracket  35  and which extend into threaded holes  17  formed in the bed  15 . In an alternative embodiment mounting bracket  35  and bed  15  may be formed as a unitary construction (not shown) from a casting or extrusion or bracket  35  may be omitted entirely as shown in the embodiment of  FIG. 8 .  
         [0023]     In the embodiment shown in  FIG. 1 , jig plate  20  is provided with structures comprising height-adjusting means including, but not limited to, the following structures. Referring to  FIG. 4  jig plate  20  is disposed in perpendicular relation to bed  15  and being attached to mounting bracket  35  in pivoting relation about a pivot bolt  22 , which extends through a hole (not shown) in the jig plate  20  and is engaged in a threaded hole  41  formed in the mounting bracket  35  ( FIG. 3 ). Jig plate  20  is imparted with limited angular rotation about pivot bolt  22  as indicated by directional arrows  27  by means of a curved slot  25 , which extends through the jig plate  20  at the location shown.  
         [0024]     Locking bolt  24  extends through slot  25  and is engaged in threaded hole  42  in the bracket  35  ( FIG. 3 ) and tightened to secure the bed  15  at the desired angular orientation relative to jig plate  20 . Adjustment of the angular orientation of bed  15  and jig plate  20  in this manner allows the position of a reaming tool  55  to be adjusted to the approximate vertical height of the bore  52  ( FIG. 7 ) in the valve body  50 , which is to be reamed oversize. Jig plate  20  is provided with flats  20   a ,  20   b , which provide a clamping surface to permit the assembled jig/work holding fixture  10  to be held in a standard bench vise (not shown). The jig plate  20  also includes a central opening  23  wherein a universal (i.e. swiveling in all axes) tool holder  30  is mounted to receive a reaming tool  55  ( FIG. 7 ).  
         [0025]     Referring to  FIG. 5A , tool holder  30  is comprised of a so-called spherical bearing, indicated generally at  45 , which includes an inner bearing element  46  and an outer race, indicated generally at  47 , which is cut into half-sections  47   a ,  47   b  along the mid-circumferential plane thereof. Half-sections  47   a ,  47   b  are press fit into mounting rings  53 ,  54 , which are seated in counterbores  56 ,  57  ( FIGS. 4, 6 ) formed in clamping plate  25  and jig plate  20  respectively. Mounting rings  53 ,  54  prevent distortion of the half-sections  47   a ,  47   b  of the outer race  47 .  
         [0026]     In a so-called spherical bearing of the type shown in  FIG. 5A , there are no ball bearings or roller elements as are found in a conventional ball bearing or roller bearing assembly. Instead a convex, semi-spherical surface of the inner bearing element  46  engages a mating concave surface of outer race  47  wherein the bearing element  46  is captured. This configuration imparts universal rotation/angular deflection of the bearing element  46  relative to a fixed longitudinal axis -A- of the outer race  47 . A spherical bearing manufactured by Torrington Company, Torrington, Conn., and identified by Part No. 15SF24 is suitable for this purpose.  
         [0027]     Still referring to  FIG. 5A  a cylindrical adapter  48  is fitted to the inside diameter of bearing element  46 , which is fitted, in turn, with a reamer or drill guide bushing  49  wherein a reamer  55  or drill bit is received ( FIG. 7 ). Thus, the longitudinal axis of reamer  55  may be rotated/deflected in relation to the axis -A- within the limits of travel of bearing element  46  to be positioned in alignment with a bore  52  for the reaming process.  
         [0028]     In another embodiment tool holder  30 ″ is comprised of a so-called spherical washer assembly, indicated generally at  60 , comprising a concave half-section  62  and a mating convex half-section  64  as shown in  FIG. 5B . In this embodiment the convex surface of half-section  64  engages the mating concave surface of half-section  62 , which imparts universal rotation/angular deflection of the convex half-section  64  relative to a fixed longitudinal axis -B- of the concave half-section  62 . A spherical washer manufactured by Reid Tool Supply, Muskegon, Mich. and identified by Part No. SPW-11 is suitable for this application.  
         [0029]     Still referring to  FIG. 5B  a reamer or drill guide bushing  49 ′ is fitted to the inside diameter of convex half-section  64  of the washer  30 ′, wherein a reamer  55  is received. Thus, the longitudinal axis of reamer  55  may be rotated/deflected in relation to axis -B-within the limits of travel of half-section  64  to be positioned in alignment with a bore  52  for the reaming process.  
         [0030]     Referring to  FIG. 6  the clamping plate  25  is utilized to lock the bearing element  46  in position within the outer race  47  to prevent misalignment of reamer  55  to the bore  52  once the desired set-up is achieved. Alternatively, clamping plate  25  locks the convex half-section  64  in position against the concave half-section  62  of the washer assembly  30 ′ once set-up is complete ( FIG. 5B ). This is accomplished by mounting the clamping plate  25  on threaded studs  12  projecting from jig plate  20  ( FIG. 1 ) via holes  26  in the clamping plate and capturing a tool holder assembly  30  or  30 ″ therebetween within the opposed counterbores  56 ,  57  formed in the clamping plate and the jig plate respectively.  
         [0031]     Wing nuts  14  or other suitable fasteners are used to tighten the clamping plate  25  against the respective tool holder assemblies  30 ,  30 ″. Once the clamping plate  25  is installed as shown in  FIG. 1 , the reamer guide bushing  49  is accessible through center opening  28  formed in the plate.  
         [0032]     Another embodiment of the present jig/fixture is illustrated in  FIG. 8 , indicated generally at  10 ′. In this embodiment the jig/fixture  10 ′ is also an assembly of components, namely, a bed, indicated generally at  15 ′, a jig plate, indicated generally at  20 ′, a clamping plate, indicated generally at  25 ′, and the universal tool holder assembly, indicated generally at  30 ′. In this embodiment it will be noted that the mounting bracket  35  ( FIG. 3 ) has been omitted.  
         [0033]     As shown in  FIG. 8 , the bed  15 ′ is a generally rectangular structure having a cutout  16 ′ formed along its centerline and extending inwardly from a first lateral edge  15   b ′ thereof. Cutout  16 ′ provides access for applying cutting fluid during the reaming process. The bed  15 ′ includes a flat, machined surface  15   a ′ whereon the valve body  50 , a transmission pump (not shown), or other work piece is secured during the reaming process.  
         [0034]     Jig plate  20 ′ is disposed in perpendicular relation to the bed  15 ′ and attached thereto in fixed relation by machine screws  21 , which extend through holes in the jig plate  20 ′ and are engaged in threaded holes  43  formed in the bed  15 ′. Jig plate  20 ′ is also provided with flats  20   a ,  20   b , which permit the assembled jig/work holding fixture  10 ′ to be held in a standard bench vise (not shown).  
         [0035]     In the embodiment shown in  FIG. 8 , jig plate  20 ′ is also provided with structures comprising height-adjusting means including, but not limited to, the following structures. The jig plate  20 ′ includes an elongated central opening  23 ′ formed between elongated adjustment slots  56 ′,  57 ′ wherein a universal tool holder  30 ′ is positioned to receive a reaming tool  55 . This configuration allows sliding adjustment of the vertical height of the tool holder assembly  30 ′ in relation to the bed  15 ′ during set-up without the pivoting mechanism of the previous embodiment ( FIG. 4 ) as hereinafter explained in further detail.  
         [0036]     Tool holder  30 ′ is also comprised of a spherical bearing (as shown and described hereinabove in  FIG. 5A ), which includes an inner bearing element  46 ′ and an outer race, which is divided into half-sections  47   a ′,  47   b ′ along the mid-circumferential plane thereof. In this embodiment the half-sections  47   a ′,  47   b ′ are machined from solid stock and the mounting rings  53 ,  54  of the previous embodiment ( FIG. 5A ) are effectively integrated into the outer race sections  47   a ′,  47   b′.    
         [0037]     Half-sections  47   a ′,  47   b ′ are seated in the opposed, elongated adjustment slots  56 ′,  57 ′ formed in clamping plate  25 ′ and jig plate  20 ′ respectively. It will be appreciated that the elongated adjustment slots  56 ′,  57 ′ provide a wider range of vertical adjustment of tool holder  30 ′ in relation to the bed  15 ′ than in the previous embodiment ( FIG. 1 ). Thus, the pivoting mechanism (i.e. pivot bolt  22  and curved slot  25 ) provided in the previous embodiment ( FIG. 4 ) is omitted in this version.  
         [0038]     Still referring to tool holder  30 ′ shown in  FIG. 8 , a cylindrical adapter  48  as shown in  FIG. 5A  is fitted to the inside diameter of bearing element  46 ′, which is fitted, in turn, with a reamer or drill guide bushing  49  wherein a reamer  55  or drill bit is received. Thus, the longitudinal axis of reamer  55  disposed within tool holder  30 ′ may be rotated/deflected in relation to the axis -A- within the limits of travel of bearing element  46 ′ to be positioned in alignment with a bore  52  in a valve body  50  ( FIG. 7 ) for the reaming process as described hereinabove.  
         [0039]     Clamping plate  25 ′ provides structures comprising locking means including, but not limited to, the following structures. Still referring to  FIG. 8  the clamping plate  25 ′ functions to lock the bearing element  46 ′ in position within the outer race half-sections  47   a ′,  47   b ′ to prevent misalignment of reamer  55  to the bore  52  once the desired set-up is achieved. This is accomplished by mounting the clamping plate  25 ′ on threaded studs  12 ′ projecting from jig plate  20 ′ via holes  26 ′ in the clamping plate  25 ′ and capturing tool holder assembly  30 ′ therebetween within the opposed adjustment slots  56 ′,  57 ′ formed in the clamping plate and the jig plate respectively. Wing nuts  14  ( FIG. 1 ) or other suitable fasteners are used to tighten the clamping plate  25 ′ against the tool holder assembly  30 ′. Once the clamping plate  25 ′ is installed, the reamer guide bushing  49  ( FIG. 5A ) is accessible through the elongated center opening  28 ′ formed in the plate  25 ′.  
         [0040]     The universal jig/holding fixtures  10 ,  10 ′ described hereinabove may be provided with structures comprising work-holding means including, but not limited to, the following structures. In the embodiment shown in  FIG. 7 , the universal jig/fixture  10  is provided with a mechanical clamping apparatus, indicated generally at  70 . Clamping apparatus  70  includes a mounting bracket  72 , which is mechanically attached to either jig plate  20 ,  20 ′ as shown. The clamping apparatus  70  also includes an adjustable foot member  75 , which engages a pivoting leg member  74  to hold the valve body  50  or other work piece in place during the reaming process. A pivoting lever arm  76  is drawn downwardly/upwardly as shown by directional arrow  77  to engage or, alternatively, release the clamping apparatus  70  by spring actuation or other similar mechanism.  
         [0041]     In the alternative, mechanical clamps such as C-clamps (not shown) may be used to secure the valve body  50  in the position shown in  FIG. 7 . The valve body  50  may also be secured at the desired position on the bed  15  by machine bolts  51  ( FIG. 7 ), which extend through existing holes in the valve body  50  and engage threaded holes  59  formed in the bed  15  at predetermined locations.  
         [0042]     In practical use the jig/work holding fixture  10  or  10 ′ to be used is initially secured in a bench vise or otherwise clamped to a workbench or machine table. Next, the approximate vertical height corresponding to the bore  52  in the valve body ( FIG. 7 ) to be reamed or drilled oversize is set. If using the jig/fixture  10  this is accomplished by adjusting the angular orientation of the bed plate  15  to the jig plate  20  to set the approximate vertical height between the bed plate  15  and the tool holder  30  as described hereinabove. If the jig/fixture  10 ′ is utilized the tool holder assembly  30 ′ is adjusted vertically within the elongated adjustment slots  56 ′,  57 ′ between the jig plate  20 ′ and the clamping plate  25 ′ to the approximate vertical height of the bore  52  to be reamed.  
         [0043]     Thereafter, a guide pin (not shown) having a terminal end conforming to the inside diameter of the OE bore  52  is inserted through a reamer guide bushing  49 ,  49 ′ in the tool holder assemblies  30 ,  30 ′ and into the bore  52 . Next, the clamping plate  25  or  25 ′ to be used is mounted on the threaded studs  12 ,  12 ′ and engaged loosely by advancing wing nuts  14  to capture the tool holder assembly  30  or  30 ′ in the desired position. Thereafter, the position of the tool holder assembly  30  or  30 ′ is fine adjusted by the technician until the guide pin rotates freely in the reamer guide bushing  49 ,  49 ′ indicating that the bore  52  and the reamer guide bushing are in concentric alignment.  
         [0044]     It will be appreciated that the tool holder assemblies  30 ,  30 ′ can be moved either vertically or horizontally relative to bed plates  20 ,  20 ′ within their respective counterbores  56 ,  57  or adjustment slots  56 ′,  57 ′ to position the tool holder assembly on the same axial centerline as the bore  52  to be reamed. A common white lithium grease may be applied to the abutting surfaces of the half-sections  47   a ,  47   b  or  47   a ′,  47   b ′ of the outer race and the adjustment slots  56 ′,  57 ′ in the case of tool holders  30 ,  30 ′ or, in the alternative, to the abutting surfaces of the half-sections  62 ,  64  and the counterbores  56 ,  57  in the case of tool holder  30 ″. The tool holder assemblies  30 ,  30 ′, or  30 ″ float in this position within the adjustment slots  56 ′,  57 ′ or counterbores  56 ,  57  respectively until clamped tight. Next, the guide pin is withdrawn from the reamer guide bushing  49 ,  49 ′ and replaced by reamer  55  or drill bit to carry out the reaming process.  
         [0045]     Although not specifically illustrated in the drawings, it should be understood that additional equipment and structural components will be provided as necessary and that all of the components described above are arranged and supported in an appropriate fashion to form a complete and operative Universal Jig/Work Holding Fixture incorporating features of the present invention.  
         [0046]     Those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods, and systems for carrying out the purposes of the present invention. For example, the present Universal Jig/Work Holding Fixture  10  can be adapted to repair hydraulic valve bores in a transmission case, which may require service. Further, with the bed plate  15  removed, the present jig/holding fixture  10  can be fastened directly to a transmission case or to any other bore that requires precision alignment/centering. In addition, the present universal jig/work holding fixture may be adapted for use with a powered reaming apparatus to control the speed and feed rates of the reamer. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.  
         [0047]     Moreover, although illustrative embodiments of the invention have been described, a latitude of modification, change, and substitution is intended in the foregoing disclosure, and in certain instances some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of invention.