Abstract:
The present invention relates to a gripping device for straightening work of a car body, with the aid of which gripping device the target of the car body being straightened is gripped and a straightening force is directed at said gripping device with the aid of a pull tool. The gripping device comprises a frame clamping member having gripping claws which can be brought around an edge of the target of the vehicle being repaired, in order to grip the vehicle, a rotatable fastening member pivotably mounted to the frame clamping member and a pull tool, such as a chain or equivalent, whereto the pull tool is fastened, whereby the rotatable fastening member is arranged to be rotatable relative to the frame clamping member of the gripping device, wherein the range of the angle of rotation of the rotatable frame fastening member is 0 to 180 °, such that opposite pull directions are achieved.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority under 35 U.S.C. § 119 of Finnish patent application Ser. No. 992323 filed Oct. 28, 1999. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a gripping device for straightening a car body. 
     BACKGROUND OF THE INVENTION 
     Fastening members of pull halters, that is, gripping devices are known in prior art to be used when a car body is straightened, with which a damaged spot in a car body, e.g. a door edge, is gripped. The straightening force created by a hydraulic cylinder is directed at the point on the vehicle to be repaired. An end of the hydraulic cylinder is fastened to a chain, and the chain further to a gripping device. The gripping device comprises two frame part halves, which by screw action are tightened relative to each other so that the fastening claws of the gripping device halves grip an edge of the target being straightened. Also known in the art is a gripping tool in which a rotatable fastening arm of the pull halter is fastened to the frame part of the gripping device. In the design known in the art said fastening arm is guided in a conductor in a groove running on the edges of the gripping device frame part, said groove comprising bearing means for enabling a rotary movement between the parts. 
     No satisfactory construction is provided by means of the rotation of a fastening member to a pull halter of a prior art gripping device structure. Since the point of rotation is located in the circumference on the edge of the frame part, said location of the point of rotation is not optimal relative to the frame part of the gripping device. In addition, the overall area of rotation in the prior art design is considerably below 180°, so that the opposite pull directions (0° and 180°) are not achieved. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide new and improved gripping device for straightening a car body part. 
     Another object of the present invention is to provide new and improved gripping device permitting a rotary range of a pull tool is 180°. 
     A gripping device of novel type is disclosed in the present application in which the fastening member of a pull tool, such as a chain, is articulated to be rotatable on the center line of the frame part of the gripping device, and moreover so that it is located both in the vertical center line of the frame part of the gripping device and in the horizontal center line defined by the fastening screws. In addition, the rotation of a pull tool is implemented so that the rotary range is 180°, whereby the opposite pull directions are reached. 
     As taught by the invention, the structure can further comprise a second gripping member of the pull tool, whereby a rectangular pull direction relative to the above mentioned 0-80° pull plane is provided as the pull direction. Said fastening member can be detachably fastened to the frame part of the gripping device that is disposed in a recess of the frame part of the gripping device, between the rotatable fastening member and the bottom of said recess such that the frame part of the gripping device is fastened to the rotatable fastening member without any need for separate additional fastening screws for securing the fastening of the second fastening member. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is described below, reference being made to a number of advantageous embodiments of the invention presented in the figures of the accompanying drawings. 
     FIG. 1A is perspective view of a gripping device according to the present invention; 
     FIG. 1B is an exploded perspective view of the gripping device according to the present invention, wherein the rotatable fastening member is detached from the frame clamping member; 
     FIG. 2A is a perspective view of a second detachable fastening member according to the present invention, wherein the pulling force to the gripping device is provided rectangularly in relation to the pulling plane of the rotatable fastening member; 
     FIG. 2B is an elevational view of a gripping device according to the present invention as seen from the direction of arrow K 1  of FIG. 1A; wherein the rotatable fastening member is rotated 90° clockwise from the position shown in FIG.  1 A and further showing the second fastening member in place; 
     FIGS. 3A and 3B are perspective views illustrating the use of the gripping device in use on the frame of a target repair vehicle, according to the present invention; 
     FIG. 3C is an perspective view of the gripping device according to the present invention, demonstrating the diverse pull directions obtainable with the rotatable fastening member and a second fastening member placed in fixed position in relation thereto; and 
     FIG. 3D is an exploded perspective view of the a frame part of the gripping device with the rotatable fastening member and the second fastening member separated therefrom. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings wherein like reference characters designate identical or corresponding features throughout the several views, and more particularly to FIGS. 1A and 1B, a gripping device according to the present invention is generally depicted by the numeral  10 . 
     The gripping device  10  comprises a frame clamping member  11  and a rotatable fastening member  12  pivotably mounted thereon. The frame clamping member  11  comprises a first clamping member  11   a   1  and a second clamping member  11   a   2  whereby said clamping members  11   a and  11   a   2  are fastened to one another by tightening screws R 1  and R 2 . Preferably, springs J 1  and J 2  are employed between the clamping members  11   a   1  and  11   a   2  around each of the tightening screws R 1  and R 2  to facilitate the opening and closing of the first and second clamping members  11   a   1  and  11   a   2  of the frame clamping member  11 . The screws R 1  and R 2  are located at opposite ends of the clamping members  11   a   1  and  11   a   2  and are linearly aligned along line Y 1 . 
     The first clamping member  11   a   1  comprises a gripping claw  11   b   1  extending perpendicularly from said first clamping member  11   a   1  and integrally formed along a terminal edge of said first clamping member  11   a   1  and substantially parallel to line Y 1 . The first clamping member  11   a   1  further comprising a rectangular recess  15  formed on an outer surface thereof and defined by a pair of parallel sidewalls  15   b   1  and  15   b   2  defining a contact surface  15   a   1 . The second clamping member  11   a   2  comprises a gripping claw  11   b   2  formed along a terminal edge of the second clamping member  11   a   2  and adapted to be aligned with the gripping claw  11   b   1  of the first clamping member  11   a   1 . 
     Formed in each of the clamping members  11   a   1  and  11   a   2  and aligned with line Y 1  is a pair of co-linear holes “d” passing through the recess  15  of the first clamping member  11   a   1  and through the second clamping member  11   a   2  (not shown). As shown in FIG. 1A, a gap is formed between the gripping claws  11   b   1  and  11   b   2 , into which an edge of a sheet of metal corresponding to a location of a vehicle to be repaired is to be disposed. 
     The rotatable fastening member  12  is generally Y-shaped and comprises a first arm  12   a   1  and a second arm  12   a   2  defining an elongated recess  12   c  in the end thereof for fastening a chain M and in particular, as seen in FIGS. 3A and 3 b , a chain link of said chain M. The rotatable fastening member  12  has a longitudinal axis which is located in the same plane T defined by the mating of the first and second clamping members  11   a   1  and  11   a   2  when pressed against the edge of the vehicle target being repaired. 
     The first arm  12   a   1  comprises a raised region  12   b   2  integrally formed and extending toward the second arm  12   a   2 . Below the raised region  12   b   2 , in the running direction of the arm  12   a   1 , is a lower region  12   b   1  defined by a shoulder  12   b  formed by the raised region  12   b   2  returning to the width of the first arm  12   a   1  and a lip  12   b   3  extending inwardly from a lower end of the first arm  12   a   1 . Formed at a distal end of the second arm  12   a   2  is a screw hole (not shown) for receiving a link screw  14  therethrough. The raised region  12   b   2  of the first arm  12   a   1  being adapted to threadingly receive the link screw  14 . 
     As seen in FIG. 1B, the link screw  14  is located on a rotational axis X 1  intersecting the connecting line Y 1  between the screws R 1  and R 2  and a vertical center line Z 1  of the frame clamping members  11   a   1  and  11   a   2  of the gripping device  11 . The rotation axis X 1  is rectangular to the plane T formed between the gripping claws  11   b   1  and  11   b   2 . The vertical center line Z 1  and the connecting line Y 1  being rectangular to one another. 
     In operation, the first and second clamping members  11   a   1  and  11   a   2  are brought together such that the edge of the vehicle being worked on is engaged therebetween and the screws R 1  and R 2  are rotatably tightened to thereby clamp the edge of the vehicle between the first and second gripping claws  11   b   1  and  11   b   2 . Once the gripping claws  11   b   1  and  11   b   2  have been tightened to each other, the edge of the vehicle being repaired is located in plane T therebetween. 
     The rotatable fastening member  12  is then pivotally secured to the frame clamping member  11  such that the raised region  12   b   2  of the first arm  12   a   1  contacts the outer surface of the rectangular recess  15  of the first clamping member  11   a   1  and the inner surface of the second arm  12   a   2  contacts the outer surface of the second clamping member  11   a   2 . The rotatable fastening member  12  is positioned such that the screw hole located at the distal end of the second arm  12   a   2  is aligned with hole “d” of the second clamping member  11   a   2 , thereby permitting the link screw  14  to pass through the hole of the second arm  12   a   2 , through both holes “d” of the first and second clamping members  11   a   1  and  11   a   2  and to threadingly engage the raised region  12   b   2  of the second arm  12   a   2 , as seen in FIGS. 1A and 1B. A pull halter, such as a chain, is then removably secured to the rotatable fastening member  12  so that one chain link of the chain M is placed transversely into the recess  12   c  of the fastening member. The chain M is now, during a pull force, locked relative to the rotatable fastening member  12 . 
     In this manner, as shown in the figures, the rotatable fastening member  12  can be rotated by angle α, said angle α being advantageously in the range 0-180°. The rotatable fastening member  12  can therefore be rotated for instance around the rotation axis X 1 , corresponding to the axis of the link screw  14 , into two opposite pull directions, each of which is parallel to the line Y 1  between the screws R 1  and R 2 . The straightening force can thereby be applied, e.g. from a straightening cylinder, to the pull halter, e.g. a chain, and further, on to the vehicle itself. 
     FIG. 2A shows a second fastening member  16  which can be used in conjunction with the gripping device  10 . The second fastening member  16  is a planar component which can be detachably secured to the gripping device  10  and the rotatable fastening member  12  when the rotatable fastening member  12  is rotated 90° relative to the line Y 1 , that is, to the center line Z 1  of the gripping device  10 . The second fastening member  16  comprises a plate having a thickness H, substantially equal to the lower region  12   b   1  of the first arm  12   a   1 . The second fastening member  16  includes a lower edge  16   a   1  and side edges  16   a   2  and  16   a   3  interconnected at a top part thereof, thereby defining a central cavity O. The cavity O comprises an elongated recess  16   b  extending into the upper end of the second fastening member  16 . In this manner a chain can be fastened to the second fastening member  16  by disposing one chain link transversely relative to is the longitudinal axis of the recess  16   b  and by taking the subsequent link through the recess  16   b.    
     FIG. 2B presents a gripping device  10 , as seen in the direction of arrow K 1  in Figure 1A, with the rotatable fastening member  12  in 90° rotation position (i.e., aligned with line Z 1 ) and with the second fastening member  16  in position. In this arrangement the second fastening member  16  is disposed within the recess  15  of the first clamping member  11   a   1 . 
     The width of the lower edge  16   a   1  of the second fastening member  16  is slightly smaller than the width of the recess  15  defined by the side walls  15   b   1  and  15   b   2 . In this manner, the second fastening member  16  can be seated in the recess  15  between the sidewalls  15   b   1  and  15   b   2  and prevented from moving in the Y 1  direction. The height and thickness of the lower edge  16   a   1  of the second fastening member  16  is such that when the lower edge  16   a   1  is seated in the recess  15 , the lip  12   b   3  of the first arm  12   a   1  snappingly fits over the lower edge  16   a   1  and the lower edge  16   a   1  seats within the lower region  12   b   1  of the first arm, thereby preventing the second fastening member  16  from moving in the X 1  or Z 1  directions. 
     As seen in FIG. 3B, with the aid of said second fastening member  16 , the pull force generated in the second fastening member  16  is directed orthogonally to the pull force generated on the first fastening member  12 . In other words, the pull direction F generated on the second fastening member  16  and the pulling point for said second fastening member  16  are located such that the pull direction F generated on the second fastening member  16  is orthogonal relative to the plane T defined by the first and second clamping members  11   a   1  and  11   a   2 . Consequently, no undesired detrimental torques are caused onto the gripping spot. 
     FIGS. 3A,  3 B and  3 C show the linking of the pull halter, of a chain M as shown in the figures, to the gripping device  10  via the rotatable fastening member  12  and/or the second fastening member  16 . The pull F is directed, for instance, from a hydraulic cylinder to a chain M, and further, therethrough to the fastening members  12  and/or  16 , and further, to the gripping device  10  and from the gripping device  10  to the target of the vehicle being straightened, via its edge. As seen in FIG. 3C, the pull F on the rotatable fastening member  12  can go through a full 180° angular range of motion due to the pivotable attachment of the rotatable fastening member  12  to the frame part  11 . 
     As taught by the invention, it is advantageous to utilize a linking fastening member  12  of the invention, in which the link point  14  is located in the proximity of the gripping claws or jaws  11   b   1 ,  11   b   2  of the gripping device  10 , and it is moreover in the central axis Z 1  of the gripping device  10 . At this stage, as the straightening is progressing, the frame part  11  rotates relative to the fastening member  12 . Therefore, due to the pivotable mounting of the rotatable fastening member  12  to the frame part  11 , torque created as a result of the pull F is minimized and the direction of the pull F is always correct relative to the gripping device  10 . 
     FIG. 3D presents a fastening device  10  with rotatable fastening member  12 . A second fastening member  16  for a chain M is presented in separation from the assembly. 
     Numerous modifications and variations of the present invention are possible in light of the teachings hereof. Therefore, it is to be understood that the invention can be varied from the detailed description above within the scope of the claims appended hereto.