Abstract:
A vehicle frame and unibody straightening jig has multiple receivers at each end for connection with pulling tower assemblies on all sides of the vehicle. Multiple pulling towers can be installed side-by-side on the same side or end of a vehicle. Receivers at the end of the jig may be installed in parallel orientation. The receivers are selectively removable. The jig also includes lateral support legs or outriggers pivotable about a 90° arc and foldable against the spine to reduce the width of the jig for storage. Height-adjustable, rotatable clamps are mounted on the outriggers for connecting the jig to a vehicle frame or unibody, The clamps are adjustable along the length of the legs to permit connection of the jig with a wide variety of vehicle frames and unibody structures. The jig also includes a carriage assembly with wheels for easy positioning beneath a vehicle.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application is a continuation-in-part of U.S. application Ser. No. 10/725,879 entitled VEHICLE FRAME STRAIGHTENING JIG filed Dec. 2, 2003, now U.S. Pat. No. 7,017,384. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention is broadly concerned with a jig for straightening a metal vehicle frame or body. More particularly, it is concerned with a portable folding jig used in connection with a plurality of pulling towers for simultaneously exerting pulling forces on a vehicle from multiple directions, several pulling towers being positionable on the same side of a vehicle.  
         [0003]     Serious collision damage to vehicles such as cars, trucks and sport utility vehicles generally includes misalignment of the frame or unibody structure. The nature and extent of such misalignment may be determined using a centerline gauge to read and record a series of measurements, which are then compared with manufacturers&#39; published vehicle dimension specifications. This enables determination of the severity of under-body damage and mapping of its various locations. The frame damage is then repaired by attaching a pulling tower or power post assembly to a point on a vehicle frame or unibody structure and actuating a hydraulic ram to pull the deformed portion of the frame and body into alignment. By performing a series of pulls, the chassis including the frame or unibody may be returned to its proper dimensions and alignment.  
         [0004]     Large, bench-type frame machines may be employed to secure the vehicle during this procedure. These machines typically include a drive-on supporting platform or table with a series of apertures spaced around the perimeter for attachment of a pulling chain which is actuated by a pulling tower. The vehicle is supported above the table by clamps to the pinch weld of a unibody, and the chains are hooked to the damaged sections. Fixed beams are coupled with the table, and are capable of mounting multiple pulling devices. These bench-type machines are powerful and effective, and they permit a full range of movement of the pulling devices to any position around the vehicle. The pulling towers can be positioned side-by-side, on one side of the table for straightening side damage to the vehicle. But these machines are expensive to purchase as well as to operate, since technicians must be trained in their use. They take up a full bay in a body shop and are too heavy and cumbersome to be moved about when not in use.  
         [0005]     Floor mounted platform systems have been developed which provide a somewhat cheaper alternative. In these systems, the platform is bolted to the shop floor and so-called “floor pots” are cemented into the floor at preselected locations for coupling with the pulling towers. These systems do not stand as high as the larger frame machines because they do not include structure for lifting the vehicle. They are large, however, taking up a full bay, and they require permanent installation.  
         [0006]     Alternatively, an individual post-type pulling device can be chained between a floor pot and the vehicle and actuated to pull one damaged section of a vehicle at a time while the vehicle remains on the floor. Such portable towers are well-suited to exert pulling force along the longitudinal axis of the vehicle. However, in order to provide a range of pulls, they must be moved about the vehicle. They are not well configured to perform side pulls, since multiple devices cannot be positioned on one side of a vehicle, and they do not make lower pulls with the power of the larger machines. Mechanics dislike working with such devices on the floor, as access to the underside of the vehicle is limited and inconvenient.  
         [0007]     In recent years there have been attempts to develop portable frame straightening machines or jigs that permit attachment of pulling towers to a portable base. Such jigs permit simultaneous attachment of more than one pulling tower, like the big machines, but the towers have a limited range of motion. In order to provide a range of pulls, the base and towers must be disengaged and repositioned. Such machines also do not permit attachment of the towers adjacent each other on one side of the vehicle, for example, to perform a side pull using multiple towers. They also do not permit attachment of multiple towers at each end of a vehicle. A particular advantage of such portable frames is that they can be stowed in a convenient location when not in use.  
         [0008]     There is still a need for an economical, portable jig that provides the complete range of pulls as well as simultaneous pulls from the same side of a vehicle that have previously been available only with large platform collision repair systems.  
       SUMMARY OF THE INVENTION  
       [0009]     The present invention provides a greatly improved vehicle frame and body straightening jig which is portable for easy positioning beneath a vehicle and connection with the frame or unibody structure, and which provides eight or more joints radiating from a central spine for attachment of pulling tower assemblies to provide a range of pulls not previously available with portable devices. The jig can support multiple pulling towers on opposite ends or sides of a vehicle. The jig can also support multiple pulling towers on the same side of a vehicle without the need for additional anchoring. It is adjustable to enable coupling with a variety of types of vehicles. The jig is relatively light weight and is easily movable when supporting a vehicle.  
         [0010]     The jig includes an elongated central spine with a plurality of receivers or sockets at each end as well as a plurality of receivers positioned at various intermediate positions along the spine. The receivers may be selectively removed and repositioned along the spine. A pulling tower assembly may be connected to each of the receivers. The jig also includes a series of laterally extending support legs or outriggers that may each be pivoted about a 90° arc from the spine and may also be folded flat against the spine to reduce the width of the jig for storage. Clamps are mounted on the outriggers for connecting the jig to a vehicle frame or unibody. The clamps are adjustable along the length of the legs to permit connection of the jig with a wide variety of vehicle frames and unibody structures. The height of the clamps is adjustable to accommodate pinch welds on a variety of vehicles having different ground clearances. The clamps are also rotatably adjustable for engagement with pinch welds that are bent out of alignment. The jig includes a carriage assembly with wheels.  
         [0011]     Objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention.  
         [0012]     The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a perspective view of a frame straightening jig apparatus.  
         [0014]      FIG. 2  is a top plan view of the jig depicted in  FIG. 1  in a folded configuration suitable for stowing.  
         [0015]      FIG. 3  is a top plan view of the of the jig at a reduced scale and showing four pulling devices attached to the jig.  
         [0016]      FIG. 4  is a top plan view of the joint section of the jig at a somewhat enlarged scale with parts of four pulling devices installed in the spider joint.  
         [0017]      FIG. 5  is a fragmentary perspective view at an enlarged scale and shows the outriggers, carriage assemblies and pinch weld clamps.  
         [0018]      FIG. 6  is a view similar to  FIG. 2  with the center socket shown in a longitudinally displaced position.  
         [0019]      FIG. 7  is a perspective view of a pulling tower assembly installed in a swivel attachment for use in conjunction with the jig.  
         [0020]      FIG. 8  is a fragmentary perspective view of the spider joint of the jig showing a swivel attachment intercoupling an attached pulling tower assembly to one socket of the joint.  
         [0021]      FIG. 9  is a top plan view of an alternate embodiment of the frame straightening jig with a pulling device shown in phantom.  
         [0022]      FIG. 10  is an enlarged perspective view of a vehicle connection device.  
         [0023]      FIG. 11  is a fragmentary perspective view of the vehicle connection device with parts omitted to show the support post with vertical adjustment apertures and frame connection device. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]     As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.  
         [0025]     Referring now to the drawing figures, the reference numeral  10  refers to a vehicle frame and body straightening jig apparatus in accordance with the invention, which is depicted in FIGS.  1 , 3 , 6 ,  7  and  8  in association with one or more pulling assemblies or towers  12  which are connected thereto by swivel attachments  13 . The jig  10  includes a base or spine member  14  having a spider joint  16  at one end, an end joint  18  at the opposite end, and at least one central or intermediate joint  20  therebetween. The apparatus  10  also includes a pair of forward outrigger assemblies  22  and a pair of aft outrigger assemblies  24 , each including a carriage assembly  26 .  
         [0026]     In more detail, the spine  14  is a fairly narrow, elongated structure. A first end terminates in the spider joint  16 , having five angularly spaced sockets or receivers including a central socket  28  aligned or coaxial with the spine  14 , a pair of orthogonal lateral sockets  30  and  32  and a pair of diagonal sockets  34  and  36  therebetween. The five sockets or receivers  28 ,  30 ,  32 ,  34  and  36  radiate at 45° intervals within a 180° arc. Each of the sockets includes an aperture  38  for receiving a pin  40  ( FIG. 4 ).  
         [0027]     The second end of the spine  14  terminates in the end joint  18 . The joint  18  includes a receiver or socket  42  having an aperture  44  for receiving an optional handle  46  or a pin (not shown). A midportion of the spine  14  includes a central or intermediate joint  20  having a pair of receivers or sockets  48  and  50  which may be in opposed or staggered relation on either side of the spine  14  or on the same side of the spine ( FIG. 6 ). The outstanding lateral end of each socket  48  and  50  includes an aperture  52  for receiving a pin  54 . A spine-contacting portion of each socket  48  and  50  includes an orthogonally expanded foot  56  ( FIG. 1 ). The length and width of the foot  56  exceed the diameter of the spine  14 . The perimeter of the foot  56  is apertured, so that the pair of sockets  48  and  50 , can be aligned in opposed relation on either side of the spine  14  and connected by means of bolts  58  straddling the upper and lower surfaces of the spine  14 . Where it is desirable to stagger or offset the sockets  48  and  50  at different locations along the length of the spine  14 , a pair of apertured plates  60  is employed to receive the bolts  58  from the sockets  48  and  50  ( FIG. 6 ).  
         [0028]     The forward and aft pairs of outrigger assemblies  22  and  24  include respective pairs of generally quadrant-shaped pivot assemblies  62  and  64 . Each outrigger assembly  22  and  24  also includes a support leg  66  and a vehicle connector assembly  68 .  
         [0029]     The forward pivot assemblies  62  each include a pair of planar, quadrant-shaped upper and lower pivot or sector plates  70  and  72  welded in horizontal, spaced, parallel relation at the perpendicular junction of the spider joint  16  with the spine  14 . Each pair of pivot plates  70  and  72  is apertured adjacent the junction for receiving a pivot bolt  74 . The curvate perimeter of each of the pivot plates  70  and  72  includes a series of spaced apertures  76  for receiving pins  78  ( FIG. 6 ) to fix the support members  66  in place.  
         [0030]     The rear pivot assemblies  64  each include a similar pair of planar, quadrant-shaped upper and lower pivot or sector plates  80  and  82 . Rearward-facing margins or radii of the pivot plates  80  and  82  are interconnected by a rear sidewall  84  ( FIG. 6 ) which serves as a stop against 180° rotation of the support legs  66  to a rearward projecting position adjacent the spine  14 . The center-facing margins or radii are interconnected by a center sidewall  86  having vertical dimensions which slightly exceed the diameter of the spine  14 . The perimeter of the sidewalls  86  are apertured so that so that a pair of rear pivot assembly sidewalls  86  can be aligned in opposed relation on either side of the spine  14  and connected using fasteners such as bolts  88  straddling the spine  14 . Alternatively, the center sidewalls  86  can be constructed in the same manner as the rear sidewalls  84 , and the center sidewalls  86  fastened in place on the spine  14  by welding. Like the forward pivot assemblies  62 , each pair of pivot plates  80  and  82  of the rear pivot assemblies  64  is apertured adjacent the junction for receiving a pivot bolt  90 . The curvate perimeter of each of the plates  80  and  82  also includes a series of spaced apertures  92  for receiving pins  94  ( FIG. 6 ). Those skilled in the art will appreciate that the pivot plates  70 ,  72 ,  80  and  82  need not be quadrant or sector shaped. It is foreseen that the pairs of upper pivot plates  70  and  80  may each be joined to form a single, generally semi-circular respective forward or rear upper pivot plate and that the pairs of lower pivot plates  72  and  82  may be similarly joined. The center sidewall  86  is preferably omitted from the rear plates  80  and  82 . Such semi-circular upper and lower plates  70  and  72  and  80  and  82  are fastened to the upper and lower surfaces of the spine  14  by means of welding or fasteners.  
         [0031]     In both forward and rear pivot assemblies  62  and  64 , the space between the parallel pivot plates  70  and  72  and  80  and  82  forms a slot  96  or  98  sized for receiving a support leg  66 . The support legs  66  are of tubular steel construction, and each is apertured through at one end to receive a pin  78  or  94  for pivotal connection with a respective pivot assembly  62  or  64 .  
         [0032]     A vehicle connector assembly  68  is attached to the outer end of each support leg  66 . Each connector assembly  68  includes a generally planar top support plate  100  and bottom support plate  102  ( FIG. 5 ). The top plate  100  is approximately square, while the bottom plate  102  is somewhat elongated. The plates are sized to exceed the dimensions of the legs  66  and are correspondingly apertured to receive bolts  104 , which straddle the sides of the legs  66  to connect the support plates  100  and  102 . The upper support plate  100  supports an upstanding stem  106  ( FIG. 6 ). A pinch weld clamp or grip  108  is vertically adjustably mounted on the stem  106 , and includes a pair of elongate clamping plates  110  and  112 . The plates are adjustably interconnected by bolts  114 . The clamp  108  is adapted to grip a peripheral pinch weld typically employed in unibody constructions to connect a lower section and a side section of sheet metal. Those skilled in the art will appreciate that, where the vehicle to be repaired is of body-over-frame construction, adaptors suitable for attachment to a section of the frame may be substituted for the clamps  112 .  
         [0033]     The jig  10  is movably supported on a carriage assembly  26 , which includes a pair of front casters  116  ( FIG. 1 ) secured by welding or other suitable means to the lower surfaces of the lateral sockets  30  and  32  of the spider joint  16 . The carriage assembly  26  also includes a pair of rear casters  118 , similarly secured to the lower surfaces of the lower pivot plates  82  of the rear pivot assemblies  64 . An outrigger caster  120  ( FIG. 5 ) is also secured to the lower surface of the portion of the elongate bottom support plates  102  that extends beyond the top support plates  100  of the connector assemblies  68  of the support legs  66 .  
         [0034]     The frame straightening jig  10  of the present invention is designed for use in conjunction with a plurality of conventional pulling assemblies or towers  12 , best shown in  FIGS. 1, 7  and  8 , each interconnected to the jig  10  by a swivel assembly or attachment  13 . The swivel attachments  13  each include a leg  122  sized for reception in one of the jig sockets  28 ,  30 ,  32 ,  34 ,  36 ,  42 ,  48  or  50  and coupled with a pivot joint  124 . The pivot joint  124  includes a pair of semicircular upper and lower pivot or sector plates  126  and  128  connected by a rear sidewall  130  along the diameter or straight margin. It is foreseen that the pivot plates  126  and  128  may be constructed in other shapes, such as, for example, the generally elongated shape depicted in U.S. Pat. No. 6,216,524 B1. A space or slot  132  between the pivot plates  126  and  128  is subdivided by a pair of diagonal sidewalls or stops  134  and  136 . The pivot plates  126  and  128  are centrally apertured to receive a pivot or link pin  138  for connecting a socket member  140 . The perimeter of the plates  126  and  128  include a series of sets of vertically aligned spaced apertures  142  for receiving a pin  144  for holding the socket  140  at a predetermined angular orientation. The outer end of the socket member  140  is also apertured for receiving a pin  148 . A carriage assembly  150  includes an elongate support plate  152  having on its upper surface a pair of upstanding right triangular supports or gussets  154  providing bracing for rigidity, and on its lower surface, a pair of ground-engaging casters  156 .  
         [0035]     Each pulling tower assembly  12  includes a telescoping section or tongue  158  pivotally connected to an upstanding post section or tower  160  and an outer carriage assembly  162 .  
         [0036]     The tongue  158  includes a first segment or section  164  ( FIG. 8 ) that is inwardly extending during normal use, and an outer second segment or section  166 . The sections  164  and  166  are vertically apertured at each end and are held in place in telescoping relation by pins  168 , except that the outer end of the second section  166  is horizontally apertured for pivotal connection with the tower section  160  by a pivot pin  170 . An inward end of the second section  166  includes a pair of upstanding ears  172 , equipped with a pair of horizontally aligned apertures  174 .  
         [0037]     The sides of the upstanding tower post or section  160  include a series of aligned, vertically spaced horizontal apertures  176  and a pair of brackets  178  which wrap around the tower post  160  and terminate in a forwardly projecting pair of ears  180 . The brackets  178  are horizontally apertured to receive pins  182  for holding them in aligned placement with a preselected horizontal aperture  176 . The ears  180  also include apertures  184 . The uppermost bracket  178  is mounted with the ears  180  projecting outwardly, and the inward facing surface of the bracket  178  includes a boss  186 . As shown in  FIG. 7 , the ears  172  and  180  are coupled with the ends of a cylinder  188 , which is actuated by a hydraulic or compressed air system (not shown). Alternatively,  FIG. 8  depicts the ears  172  and  180  coupled with a rigid link  190  as may be employed when the tower assembly  12  is employed as a fixed position anchor.  
         [0038]     The pulling tower carriage assembly  162  includes first and second support plates  192  and  194  ( FIG. 1 ) mounted below respective first and second sections  164  and  166 . The first support plate  192  is elongate, including on its upper surface a pair of upstanding right triangular supports or gussets  196  for preventing lateral movement of the first section  164  on the plate  192 . The second support plate  194  is generally square shaped. The lower surfaces of each support plate  192  and  194  include a pair of ground-engaging casters  198 .  
         [0039]     The jig  10  is preferably formed of square tubular steel construction, although round tubular steel or solid bars may also be employed. Those skilled in the art will appreciate that, while the drawing figures depict a jig  10  having eight socket receivers with a five socket spider joint  16  at one end and an end joint  18  having one receiver  42 , the end joint  18  may also be constructed to include a spider joint so that the jig may include  12  sockets. It is also foreseen that the intermediate joint  20  may include more than two sockets  48  and  50 , so that the jig may include as many as  14  or more sockets.  
         [0040]     In use, a mechanic or technician employs a jack to raise one end of a vehicle such as a car, truck or the like. The jig  10 , in normal storage configuration with the outriggers  22  and  24  folded against the spine  14 , is easily rolled into place below the vehicle by guiding the carriage assembly  26  using the optional handle  46 . The mechanic positions the jig  10  so that the spine  14  is aligned with the longitudinal axis of the vehicle, with the spider joint  16  at one end and the end joint  18  at the other. If the end socket  42  is to be used, the handle  46  is removed. The outriggers  22  and  24  are unfolded from the spine  14  and extended laterally, and the connector assemblies  68  are adjusted along the length of the legs  66  as may be needed to connect the pinch weld or jack tabs between the clamping plates  110  and  112 . If necessary, one or more outriggers may also be rotated slightly to achieve alignment of the connector assemblies  68  with the pinch weld. The clamp  108  is then tightened in place over the pinch weld. Depending on the pattern of the collision damage and the necessary pulls, it may be desirable to first remove one of the wheels in order to facilitate placement of an outrigger  22  or  24 . The clamped end of the vehicle is then lowered, and the process is repeated at the opposite end. In this manner, the jig  10  is connected through the outriggers  22  and  24  to the vehicle by two pairs of clamps  108  on each side of the vehicle, each pair of clamps  108  being in approximately opposed relation.  
         [0041]     The mechanic next connects a pulling tower assembly  12  to a swivel attachment  13  by inserting the end of the tongue  158  into the socket  140 , aligning the apertures and inserting a pin  168 . The swivel attachment leg  122  is inserted into a socket of the jig  10 , for example the lateral socket  30 . The pin  144  of the swivel attachment socket member  140  may be removed and the socket member  140  rotated in the pivot joint  124  to a desired position and the pin  144  replaced to secure the angular attitude of the attachment  13 . One end of a chain (not shown) is then coupled with the upper tower bracket  178  and the other end attached to a point on the vehicle to be pulled.  
         [0042]     The process may be repeated to install a second pulling tower assembly  12  in the intermediate socket  48 , for example, to permit a simultaneous pull using side-by-side pulling assemblies  12 . The hydraulic cylinders  188  are next actuated to perform the pull. It is foreseen that a hydraulic cylinder may be coupled with the boss  186  of the upper bracket  178 , and that a pulling tower assembly  12  may be employed to push against the vehicle rather than pull. It is also foreseen that any or all of the five sockets  28 ,  30 ,  32 ,  34  and  46  of the spider joint  16  as well as the two sockets  48  and  50  of the intermediate joint, and the end socket  42  may be equipped with pulling tower assemblies  12  for simultaneous side-by-side, diagonal, or opposed pulling, pushing, or any combination thereof. Where the vehicle is of body-over-frame construction, the connector assemblies  68  may be equipped with adaptors to receive a frame member. Once initial frame straightening pulls are made measurements can be made to determine if desired alignment of the frame has been achieved. IF not, adjustments in the positions of the tower  12  can be made and the process repeated until the frame alignment has been restored.  
         [0043]     The jig may also be used as a dolly, to move the vehicle about on the floor of the shop. When the pulling operations have been completed, the installation process is reversed, including replacement of any wheels that have been removed. The jig  10  is then folded to its storage position by rotating the forward and aft outriggers  22  and  24  to a position adjacent the spinel 4 . In this manner, the width of the jig  10  is substantially reduced so that it can be stored out of the way.  
         [0044]     An alternate embodiment of the vehicle frame straightening jig apparatus is generally designated by the reference numeral  210  and is depicted in  FIGS. 9-11  in association with a pulling assembly or tower  212 , one or more of which may be connected directly to the jig as shown in  FIG. 9 , or may be interconnected to the jig  210  by a swivel attachment  213  substantially as previously described. The alternate jig  210  includes an elongated base or spine member  214  having first and second joints  216  and  218 , pairs of first and second outrigger assemblies  222  and  224 , each including an outrigger support leg  266  coupled with a carriage assembly  226  ( FIG. 10 ) and a vehicle connection device  268 , and connected to the spine  214  by respective first and second pairs of pivot assemblies  262  and  264  substantially as previously described.  
         [0045]     The spine  214  has a pair of opposite ends  215  and  217 . The first end  215  is coupled with a plurality of sockets or receivers to form a first joint  216 , including a central receiver  228 , and spaced apart side receivers  230  and  232 . The central receiver  228  is aligned or coaxial with the spine  214  and the two elements may be of unitary construction. The side receivers  230  and  232  may be configured in opposed relation to form a generally T-shape in combination with the central receiver  228  for opening in a transverse orientation as shown in  FIG. 9 , or they may be in a staggered or offset transverse relation to the spine  214  to form an approximately Z-shape or one or both of the receivers may be angled or generally diagonal in spaced relation to the central receiver  228 . Where both of the receivers  230  and  232  are angled, the overall configuration will be similar to that of receivers  34  and  36  previously described. The illustrated receivers  230  and  232  may also be selectively disengaged and removed from the spine  214 .  
         [0046]     Each of the sockets or receivers is engageable with a pulling assembly  212  or with a swivel attachment  213  which in turn engages a pulling assembly  212  for pivoting or swiveling of the pulling assembly  212  to achieve a preselected pulling angle with respect to a vehicle. The sockets  230  and  232  each include an orthogonally expanded foot  260  that is sized to exceed the diameter of the spine  214  and apertured adjacent the perimeter. The sockets are held in place on the spine  214  by bolts  258  through pairs of opposed feet  260 . The first pair of pivot assemblies  262  is attached to the spine  214  in similar fashion. Where the sockets  230  and  232  or pivot assemblies  262  are not installed in offset relation, a plate is employed similar to that shown in  FIG. 6  and previously described.  
         [0047]     The opposite second end of the spine  217  is also coupled with a plurality of sockets to form a second joint  218  including a central receiver  242  and parallel spaced apart side receivers  244  and  246 . The central receiver  242  is coaxial with the spine and the two elements  242  and  218  may be of unitary construction. The side receivers  244  and  246  are attached to the pivot assemblies  264  by means of pairs of plates  270  that are welded onto the upper and lower surfaces of each receiver  244  and  246  and attached to the respective tops and bottoms of the upper and lower pivot plates  280  by means of bolts  272 . While the bolts  272  enable the side receivers  244  and  246  to be selectively removed, it is foreseen that the plates  270  could also be welded or otherwise permanently secured to the respective upper and lower surfaces of the pivot plates  280 . The receivers  242 ,  244  and  246  of the second joint  218  are depicted in  FIG. 9  in spaced parallel relation for opening in the same direction, and it is also foreseen that they may be connected to the spine  214  in a generally T-shape, offset or Z-shape for opening in a transverse orientation, or they may be connected to form an angled shape as previously described with respect to the receivers of the first joint  216 .  
         [0048]     The spine  214  is supported at either end by a carriage assembly (not shown). The carriage assembly at the first end of the spine  215  includes a pair of ground engaging front wheels or casters as previously described and fastened to a plate  296  ( FIG. 9 ) that is coupled with the central socket or receiver  228  in supporting relation. Where the receiver  228  is constructed to be removable from the spine  214 , then the plate  296  may be coupled behind the receiver  228  with the first end of the spine  215 . A pair of upstanding, generally triangular gussets  298  extend between the plate and the receiver  228  to provide lateral support. The plate  296  and gussets  298  may be connected with the spine  214  or central receiver  228  by welding or any other suitable means of attachment. The carriage assembly at the second end of the spine  217  is of similar construction, except that it may be secured to the lower surfaces of the rear pivot plates  280  without gussets.  
         [0049]     Each of the outrigger support legs  266  is also supported by a carriage assembly  226  adjacent the outboard end ( FIG. 10 ). Each outrigger support leg  266  also supports a vehicle connection device  268  for connecting the jig  210  to a vehicle frame or body. The vehicle connection device  268  includes top and bottom support plates  300  and  302  apertured to receive bolts  304 . The bottom support plate  302  is secured atop the wheels or casters  238 , and the top support plate  300  is adjustably connected to the bottom support plate  302  in clamping relation to the outrigger legs  266  as previously described.  
         [0050]     The top plate  300  is apertured for reception of a generally cylindrical and upright or vertical sleeve  306 , the lowermost end of which is secured to the uppermost surface of the bottom plate  302  as by welding or the like. The bottom plate  302  includes a slightly smaller aperture aligned with the sleeve  306 , for sliding reception of a vehicle support post or stem  310  therethrough. The sleeve  306  is sized for sliding, telescoping reception and  3600  axial rotation of the upstanding vehicle support post  306  to provide the vehicle connection device  126  with two degrees of freedom. Because the top and bottom plates  300  and  302  are of different lengths, the sides and one of the ends are aligned, with one end of the bottom plate  302  extending beyond the corresponding end of the top plate  300 . The aperture in the bottom plate  302  is preferably centrally located to provide greater stability, necessitating offset of the aperture in the top plate  300  to compensate for the shorter length of the plate.  
         [0051]     The sleeve  306  includes a plurality of radially spaced apertures or holes  308  aligned in spaced relation with the upper margin thereof. The post  310  includes a plurality of sets of vertically spaced apertures or holes  312  along the length thereof. A removable pin  314 , illustrated as L-shaped, is provided for reception through the aligned apertures  308  and holes  312  for coupling the post  310  with the sleeve  306  when the post  310  and attached pinch weld clamp  316  are positioned at a preselected height and angle of rotation.  
         [0052]     The upper end of the post  310  is coupled with a pinch weld clamp or grip  316 , which includes an elongate, generally flat and rectangular supporting crossbar  318  supporting two pairs of shorter clamping jaws  320 . While the clamp jaws  320  are depicted as having a generally C-shaped cross section, they may also be of generally flat, ribbed, tongue and groove or any other configuration suitable for efficiently grasping and holding a vehicle pinch weld. The upper end of the post  310  is notched through for reception of the crossbar  318 , which may be secured by welding or other suitable means. One of each pair of clamp jaws  320  may be secured to the crossbar  318 , as by welding. Pairs of threaded bolts  322  through the crossbar  318  adjustably secure the clamp jaws  320  to each other in pairs.  
         [0053]     In use, the outrigger support legs  266  are pivoted to a folded position generally parallel and adjacent to the spine member.  214  Where necessary the connection devices  268  may be removed from the jig  210  to improve clearance. A mechanic or technician raises the vehicle, rolls the jig  210  underneath and extends the outriggers  222  and  224  substantially as previously described.  
         [0054]     The mechanic assesses the longitudinal alignment of each of the pinch weld clamps  316  with the vehicle pinch welds by sight and, if necessary, adjusts the alignment of one or more of the clamps  316  by removing the pin  314  and rotating the clamp  316  and attached post  310  within the sleeve  306  until the clamp aligns with the pinch weld. Where the vehicle is particularly long, it may be desirable to move the outriggers closer together for stability. The first outrigger assembly  222  may be repositioned along the spine  214  so that it is closer to the second outrigger assembly  224  by loosening the bolts securing the pivot assemblies  262  and sliding the assemblies along the spine  214  toward the center.  
         [0055]     The height of the clamp  316  is adjusted by raising the post  310  to the desired height. The pin  314  is then reinserted through a selected one of the sleeve apertures into an aligned vertical post hole  312 . The vehicle is next lowered until the clamps  316  engage the pinch welds. The opposed pairs of clamp jaws  320  are tightened over the pinch welds by tightening the bolts  322 .  
         [0056]     The mechanic next connects pulling tower assemblies  212  to one or more swivel attachments  213  which are inserted into selected receivers  228 ,  230 ,  232 ,  242 ,  244  and/or  246 , as well as any intermediate receivers (not shown) and the pulling operation is accomplished substantially as previously described. Advantageously, three pulling towers  212  may be positioned at each end of the spine, and additional towers may be positioned on optional receivers installed on the center portion of the spine. The pulling towers  212  and swivel attachments  213  may be freely repositioned within selected receivers for subsequent pulls without the need for remounting or repositioning of the vehicle on the jig  210 . The large number of receivers in combination with their distribution at selected points all around a vehicle and their use in combination with the swivel attachments  213  and known rotatability of the pulling towers  212  permits a flexible combination of compound and/or complex pulls from virtually any location with respect to a vehicle.  
         [0057]     It is to be understood that while certain forms of the present invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangement of parts described and shown.