Abstract:
A shim carrier assembly for optionally retaining shims therein, wherein the carrier has at least three intercontiguated planar portions with holes or slots therein, such that a fastener may be inserted through the holes or slots for aiding in the shimming of fastened components.

Description:
TECHNICAL FIELD 
     The present invention relates generally to mechanical fasteners and more particularly to mechanical fasteners used in conjunction with shims. 
     BACKGROUND OF THE INVENTION 
     A rear wheel drive vehicle typically includes a transmission having an output shaft connected through an elongated driveshaft to an axle assembly. The driveshaft typically comprises two or more propeller shafts which are connected with a universal joint. 
     One of the propeller shafts is supported by a center bearing secured to the underbody of the motor vehicle. The driveline is positioned for proper orientation and alignment by placing shims or washers during installation between the center bearing and underbody. 
     Various mounting and positioning schemes are disclosed in the prior art for insuring driveline propeller shaft alignment with the center bearing and the vehicle body. Currently, manufacturers use washers to shim propeller shafts. However, the use of loose shims or washers is cumbersome in the assembly plant environment. 
     U.S. Pat. No. 5,469,931 to Kawata et al. describes an attachment means provided by engaging serrations and a locking nut for connecting and aligning the propeller shafts with the center bearing. U.S. Pat. No. 5,829,892 to Groves discloses a center bearing collar assembly having a bearing race with a rigid fixed mounting scheme requiring washer shims to provide incremental changes in vertical alignment. 
     U.S. Pat. No. 5,314,380 to Yamamoto teaches an improved structure of a universal joint for reducing swing torque having a spider axially rotated on a bearing cup with no shim means provided for self-retaining to the floor pan. U.S. Pat. No. 5,452,548 to Kwon also teaches a bearing structure with an isolation and anchor device for supporting bridges and other vertical structures formed with a multilayer pattern of metal plates and bars located in the center bearing unit to improve vertical resistance as well as horizontal and torsional rigidity. 
     U.S. Pat. No. 5,703,796 to Moradi et al. relates to an apparatus and method for aligning a driveline in a motor vehicle by positioning a center bearing to the body of the motor vehicle to further support the driveshaft. The position of the driveline is then measured and a shim thickness is calculated for installation between the center bearing and the body. None of the five recited prior art patents either teach or disclose the subject invention shim carrier assembly and self-retaining feature. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the prior art disadvantages by providing self-retaining attachment means between the driveline, center bearing, and underbody when the propeller shaft assembly is installed to the vehicle. The self-retaining attachment means is provided with a shim stock common carrier of various shim thicknesses for proper alignment. Without the common carrier and self-retaining feature, shims must be placed over each stud while the propeller shaft is being attached to the vehicle underbody. 
     It is an object of the present invention to minimize the number of sub-component shims by allowing shim stock of various thicknesses to be assembled into a common carrier. This overcomes an inherent disadvantage in prior art attachment schemes for mounting the propeller shaft and center bearing assembly to the propeller attachment studs in the floorpan. Without the common carrier and self-retaining shim stock feature of the present invention, shims must be manually placed over each stud while the propeller shaft and center bearing assembly is being attached to the underbody. 
     The common shim carrier assembly slides onto the propeller shaft center bearing to allow the propeller shaft center joint to operate at the desired orientation. This is achieved because the shims are positioned between the propeller shaft center bearing and the body when the propeller shaft is installed to vehicle floorpan. Ultimate retention of the shim carrier is achieved with the fasteners that hold the propeller shaft to the body. 
     The present invention overcomes the disadvantages of the prior art approaches and simplifies the attachment schemes by providing a common shim carrier formed from malleable sheet metal or other material preferably in a substantially flattened “I” shape having three layered intercontiguated planar portions, generally parallel to one another and provided with holes or slots for attachment and alignment through the three planar portions. 
     Other features, objects, and advantages of the present invention will be become apparent from the following detailed description of the drawings, the preferred embodiments, and the claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows an exploded perspective assembled view of the preferred essentially “S” shaped embodiment of the common shim carrier ( 100 ) with the yoke and center bearing assembly. 
     FIG. 2 is an end view showing a yoke and center bearing assembly with the common shim carrier ( 100 ) and shims ( 70 ) in a fully assembled and mounted position. 
     FIGS. 3-5 show various flattened and unfolded plan view configuration embodiments of the common shim carrier ( 100 ) with the first ( 10 ), second ( 20 ), and third ( 30 ) intercontiguated planar portions. 
     FIG. 6 is a flattened plan view of the preferred essentially “S” shaped common shim carrier ( 100 ) embodiment with the three layered intercontiguated planar portions ( 10 ), ( 20 ) and ( 30 ); transition portions ( 16 ), ( 26 ); contiguated edges ( 17 ), ( 18 ), ( 27 ), ( 28 ); lateral edges ( 13 ), ( 23 ), ( 33 ); notches ( 15 ), ( 25 ); and tabs ( 14 ), ( 24 ) formed from said notches. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     To assist the reader in understanding the present invention, all reference numbers used herein are summarized in the table below, along with the elements they represent as shown in FIGS. 1-6 of the drawings: 
       10 =First planar portion 
       11 =First end edge 
       12 =Hole or slot in first planar portion 
       13 =Lateral edge(s) of first planar portion 
       14 =Tab formed along lateral edge  13   
       15 =Notch(es) on either side of tab  14   
       16 =First transition portion 
       17 =First contiguated edge 
       18 =Second contiguated edge 
       20 =Second planar portion 
       22 =Hole or slot in second planar portion 
       23 =Lateral edge(s) of second planar portion 
       24 =Tab formed along lateral edge  23   
       25 =Notch(es) on either side of tab  24   
       26 =Second transition portion 
       27 =Third contiguated edge 
       28 =Fourth contiguated edge 
       30 =Third planar portion 
       31 =Second end edge 
       32 =Hole or slot in third planar portion 
       33 =Lateral edge(s) of third planar portion 
       37 =Fold line 
       39 =Folded-up flap 
       70 =Shim 
       72 =Hole or slot in shim 
       73 =Lateral edge(s) of shim 
       74 =Relief formed along lateral ( 73 ) 
       100 =Carrier 
     T=Thickness of shim 
     The shim carrier assembly as generally represented in the subject invention and further defined by the preferred embodiment comprises an essentially “S” shaped shim carrier  100 , formed from malleable sheet metal and substantially flattened with first  10 , second  20  and third  30  layered intercontiguated folded planar portions, generally parallel to each other and provided with common holes or slots  12 ,  22 ,  32  for engaging and positioning a perpendicular fastener shaft for mounting the propeller shaft, yoke, and center bearing assembly to the underbody floorpan. At least one shim  70  can be disposed between any two of the planar portions. 
     In the preferred embodiment of FIG. 6, as shown in FIGS. 1 and 2, shims  70  are captured between the first  10  and second  20  generally parallel planar portions. The second  20  and third  30  planar portions form a clip portion having the folded up flap  39  of the third planar portion at one end of the shim carrier. The flap  39  assists in sliding the clip portion  20 ,  30  onto a support flange (workpiece) for holding the shim carrier assembly  100 ,  70  on the flange of the propeller shaft center bearing with the shims between the first  10  and second  20  planar portions positioned between the flange (workpiece) and a support strap (workpiece) for providing a predetermined spacing between the workpieces as shown in FIGS. 1 and 2. 
     The essentially flattened shim carrier  100  of FIG. 6 is folded about the first  17  and second  18  contiguated edges of the first planar portion  10  and the third  27  and fourth  28  contiguated edges of the second planar portion  20  to form the third planar portion  30  of the “S” shaped shim carrier. Notches  15  are provided on opposite sides of the first planar portion  10 , and notches  25  are provided opposite sides of the second planar portion  20 , forming the tabs  14  along the lateral edge  13  and the tabs  24  along the lateral edge  23  to retain the shims  70 . The folded-up flap  39  is then formed from folding about the fold line  37  in the third planar portion  30 , thus completing the “S” shaped shim carrier assembly  100  for retaining shims  70 . 
     As shown in FIGS. 1-2, the shim carrier assembly  100  slides onto the propeller shaft center bearing to allow the propeller shaft center joint to operate at the desired orientation. This is achieved by positioning the shim carrier assembly  100  between the center bearing and the body when the propeller shaft is installed to the vehicle. Ultimate retention is then provided by the shim carrier assembly  100  with the fasteners that hold the propeller shaft to the body. 
     The subject invention minimizes the number of subcomponent shims  70  by allowing shim stock of various thicknesses to be assembled into a common shim carrier  100 . Various thicknesses can be achieved with the use of separate shim blanks. The shim carrier  100  is common between all shim thicknesses. Common washers may also be used within the shim carrier. 
     Various other modifications to the present invention may occur to those skilled in the art to which the present invention pertains. For example, the original flattened blank, forming the intercontiguated planar portions from which the shim carrier assembly  100  is fabricated, could be an essentially in-line straight configuration as illustrated in FIGS. 3-6; or could be essentially “I”, “L”, “C”, “T”, “t”, “U”, “E” shaped, etc. 
     The intercontiguated planar portion segments are essentially rectangular in shape as in FIGS. 4-5; however, they could also have rounded corners as in FIGS. 3 and 6, or circular segments resembling “chain links,” or any other geometric configuration. The completed fabricated shim carrier assembly may be essentially “S” shaped in the end view as shown in FIGS. 1 and 2, but could be “C” shaped, or “E” shaped, or the like, depending upon the shape of the original flattened blank from which it is fabricated, and how it is folded about the intercontiguated edges. 
     The shim carrier  100 , as well as shim stock blanks, can be formed from various materials. Although the shim carrier  100  in the preferred embodiment is formed from sheet metal, it could be fabricated from other materials as well. For example, the shim stock blanks could well be made of non-metallic materials such as rubber, plastic, or even wood. 
     Other modifications not explicitly mentioned herein are also possible and within the scope of the present invention. It is the following claims, including all equivalents, which define the scope of the present invention.