Abstract:
A suspension link assembly for a vehicle suspension system. A preferred form comprises only three different kinds of components. The components are a stud shaft, a sleeve nut and a grommet. In an alternative form a barrel-shaped, molded plastic spacer is added. The link assembly lends itself to partial preassembly off the vehicle assembly line and delivery to the assembler as a kit.

Description:
FIELD OF THE INVENTION 
     This invention relates generally to vehicle suspension systems. It relates particularly to a link assembly for a suspension system. 
     BACKGROUND OF THE INVENTION 
     Motor vehicles have long been provided with independent suspension systems to absorb road shocks and other vibrations and provide a smoother, more comfortable ride. In suspension systems of this type, a stabilizer bar is normally incorporated to increase roll resistance and improve the steering to stability of the vehicle. Typically, the stabilizer bar is a torsion rod which extends transversely of the vehicle. It has an integral crank arm provided at each end. The rod is rotatably supported from the vehicle chassis adjacent each crank arm, and each crank arm is coupled to a suspension arm by a connector link assembly. 
     When the vehicle is subject to forces which cause it to roll, the crank arms pivot relatively about the longitudinal axis of the rod, against the torsional resistance of the rod. Torsion forces which are exerted through the crank arms urge the suspension arms of the vehicle back toward their normal position. This type of stabilizer bar acts in a manner such that when paired left and right wheels differ in level from each other due to a cornering maneuver, for example, the vehicle body will be prevented from excessive rolling or leaning to either side by torsional resistance of the stabilizer bar. 
     The link assembly, which connects the crank arms of the torsion rod to the vehicle body and to the suspension arms, is generally one of two types. It is either a bolt-type assembly or a stud-type assembly. In a bolt-type assembly a suitably dimensioned bolt and nut are used to connect the stabilizer bar to the vehicle suspension arm. Pliable bushings or grommets assembled on the bolt engage the exterior surfaces of the stabilizer bar arms and the vehicle suspension arms. A pair of similarly shaped grommets engage the interior surfaces of the respective vehicle elements and are in engagement with a pair of inner washers which are maintained at a predetermined spaced distance by a cylindrical sleeve mounted on the shaft of the bolt. 
     In a stud-type assembly, the stud shaft has both ends threaded. Accordingly, retainer nuts are threaded onto both ends of the stud shaft. Once again, pliable bushings or grommets assembled on the stud shaft engage the exterior surfaces of the stabilizer bar arms and the vehicle suspension arms. A pair of similarly shaped grommets engage the interior surfaces of the respective vehicle elements and are in engagement with a pair of inner washers which are maintained at a predetermined spaced distance by a cylindrical sleeve mounted on the shaft of the stud. 
     Regardless of whether a bolt or stud-type link assembly is employed, prior art constructions have generally suffered from complexity and cost shortcomings. Such assemblies normally comprises at least four, and sometimes as many as six, different components. Furthermore, assembly is normally done on the vehicle assembly line from these many components. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide an improved suspension link assembly for a vehicle suspension system. 
     Another object is to provide an improved stud-type suspension link assembly which is simpler in construction and less expensive than existing link assemblies. 
     Still another object is to provide a stud-type suspension link assembly which is easier to fabricate and install than existing link assemblies. 
     Yet another object is to provide a stud-type suspension link assembly which is composed of only three different kinds of components. 
     A further object is to provide a stud-type suspension link assembly which can be delivered to the vehicle manufacturer&#39;s assembly line in preassembled sub-assemblies. 
     The foregoing and other objects are realized in accord with the present invention by providing a suspension link assembly which, in its preferred form, comprises only three different kinds of components. The three components are a stud shaft having identical threaded sections at each end, a sleeve nut and a grommet. Four of the grommets, four of the sleeve nuts and a stud shaft make up the assembly. 
     Each assembly thus comprises nine components; four sleeve nuts, four grommets and a stud shaft, but only three different kinds of components. Furthermore, the vehicle manufacturer can purchase and deliver the assemblies to the vehicle assembly line as a kit comprising only two different sub-assemblies. In one, the stud shaft is preassembled with two sleeve nut and grommet sub-assemblies. The other comprises a sleeve and grommet sub-assembly, of which two are called for. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention, including its construction and method of operation, is illustrated more or less diagrammatically in the drawings, which: 
     FIG. 1 is a perspective view of a link assembly comprising features of the present invention; 
     FIG. 2 is an end view of the link assembly of FIG. 1; 
     FIG. 3 is a sectional view along line  3 — 3  of FIG. 2, with portions of a vehicle stabilizer bar crank arm and a suspension system arm shown connected by the link assembly of FIGS. 1 and 2; 
     FIG. 4 is an enlarged side elevational view of a sleeve nut and grommet sub-assembly for the link assembly of the invention; 
     FIG. 5 is an exploded view of the three sub-assemblies which make up a suspension link assembly embodying features of the present invention; 
     FIG. 6 is a side elevational view of a modified stud shaft; 
     FIG. 7 is a sectional view taken along line  7 — 7  of FIG. 6; 
     FIG. 8 is a side elevational view of a spacer for a second embodiment of link assembly comprising features of the invention; and 
     FIG. 9 is a sectional view of the second embodiment of link assembly. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, a suspension link assembly embodying features of the invention is seen generally at  10  in FIGS. 1-3. The link assembly  10  includes a stud shaft  15  on which four identical sleeve nut and grommet sub-assemblies  21 - 24  are mounted. 
     The stud shaft  15  includes a shaft body  31  of predetermined length. The shaft body  31  has threaded sections  33  and  34  at each end. The threaded end sections  33  and  34  terminate in stops formed by chamfers  35  and  36 , respectively. The chamfers  35  and  36  are at opposite ends of a center spacer section  38 . The section  38  has flats formed on opposite sides, as at  39 , for reasons hereinafter explained. The stud shaft  15  is fabricated of steel which is plated for corrosion resistance. 
     Since the nut and grommet sub-assemblies  21 - 24  are identical, only the sub-assembly  21  is described in detail. Corresponding reference numerals may be applied to corresponding components in each of the other sub-assemblies  22 - 24 . 
     Referring to FIG. 4 in addition to FIGS. 1-3, the sub-assembly  21  comprises a tubular sleeve nut  41  and a grommet  42 . The nut  41  is formed from heat treated carbon steel. The grommet  42  is molded of resilient material such as natural rubber or polyurethane or the like. 
     The nut  41  comprises a tubular segment  51  with a bore  52  which is internally threaded at  53 . Both ends of the threaded bore  52  are formed with a 45° chamfer, as at  55  and  56 . A shallow, cup-shaped head  57  is formed at one end of the tubular segment  51 . The periphery  58  of the head is polygon-shaped, for reasons hereinafter explained. 
     The molded elastomer grommet  42  has a cylindrical bore  61  through it. The bore  61  has an inside diameter (ID) which is slightly smaller than the outside diameter (OD) of the tubular segment  51  in the nut  41 . 
     The grommet  42  also has a generally “bee-hive” shape external surface  63  on its inner end. Its outer end has a slightly spherical surface  64  which is complementary in shape to the disc-shaped head  57  in the nut  41 . 
     The sleeve nut and grommet sub-assembly  21  is assembled by press fitting a grommet  42  over a tubular segment  51  of a nut  41  until the surface  64  of the grommet seats against the cup-shaped head  57  of the nut. Since the ID of the bore  61  is slightly smaller than the OD of the nut&#39;s tubular segment  51 , the grommet resiliently grips the nut  41 . When assembled, the free end  66  of the tubular segment  51  on the nut  41  protrudes slightly beyond a cylindrical lip  67  on which the end surface  68  of the grommet  42  is formed. 
     Referring now also to FIG. 5, the three different components of the assembly  10 , the stud shaft  15 , sleeve nuts  41  and grommets  42  are optionally preassembled by the vehicle manufacturer into three component assemblies A, B and C before being sent as a kit to the assembly line. In a pre-assembly operation, four sleeve nut and grommet sub-assemblies  21 - 24  are assembled in the afore-described manner. Two of the sleeve nut and grommet sub-assemblies,  22  and  23  in the drawings, are then threaded onto opposite end sections  33  and  34 , respectively, of the stud shaft body  31 . This creates the component assembly B. Two sleeve nut and grommet sub-assemblies  21  and  24 , which are identical to each other, comprise the component assemblies A and C. 
     Referring again to FIG. 3, the three component assemblies A, B and C are mated with the suspension arm X and a torsion bar arm Y in the manner illustrated. The opposite ends of the component assembly B are inserted through suitably dimensioned apertures Xap and Yap in the respective arms X and Y. The apertures Xap and Yap have diameters large enough so that a cylindrical lip  67  of a corresponding grommet  42  extends into each aperture. The sleeve nut and grommet sub-assembly  21  is then threaded onto one end of the shaft body  31  and the sub-assembly  24  is threaded onto the other end. Corresponding grommets  42  engage respective arms X and Y in the manner just described. 
     This initial assembly is easily accomplished by hand. Only three items (assemblies A, B and C) need be handled by the assembler so assembly time is minimized. The assembler then grips the shaft body  31  on the flats  34  with a wrench and tightens the sleeve nuts  41  (the periphery  58  of the head  57  is polygon shaped) with another wrench. 
     When fully assembled, the ends  68  of the tubular segments  51  abut each. The faces  63  of opposed bushings  42 , which engage respective arms X and Y, are then spaced from each other a distance which just accommodates the thickness of corresponding arms. 
     Referring now to FIGS. 6 and 7 of modified form of stud shaft for a link assembly  10  is shown at  115 . The stud shaft  115  comprises a shaft body  131  having threaded end sections  133  and  134 , and a center spacer section  138 . 
     One end of the spacer section  138  has four protruding upsets  135  formed therein. The other end has four protruding upsets  136  formed therein. Flats  139  are formed on opposite sides of the spacer section  138 . 
     The stud shaft  115  is employed in the manner of link assembly  10 . The upsets  135  and  136  serve as stops for two inside sleeve nut and grommet sub-assemblies identical to sub-assemblies  22  and  23  previously described. In all other respects the link assembly would be identical to assembly  10 . 
     Referring now to FIGS. 8 and 9, a link assembly comprising a second embodiment of the invention is seen generally at  210 . The link assembly  210  is identical to the assembly  10  previously described except for two features. First, the sleeve nut and grommet assemblies  22  and  23  are replaced by a unitary spacer  225 . Second the center spacer section  238  of the stud shaft body  231  does not have opposed flats formed on it but, instead, has allen-wrench sockets  237  formed axially into its opposite ends. 
     The spacer  225  is a hollow, barrel shaped body molded of polyurethane. It includes a plurality of longitudinally extending ribs  227  which serve to enhance its axial rigidity and strength. It has annular collars  228  formed at each end. The diameter of each collar  228  is such that it seats in the corresponding suspension arm aperture. 
     While preferred embodiments of the invention have been described, it should be understood that the invention is not so limited, and modifications may be made without departing from the invention. The scope of the invention is defined by the appended claims, and all devices that come within the meaning of the claims, either literally or by equivalence, are intended to be embraced therein.