Patent Publication Number: US-2009230713-A1

Title: Link system and method therefor

Description:
TECHNICAL FIELD 
     The present disclosure generally relates to link systems and methods of assembling link systems. 
     BACKGROUND 
     Many link systems are assembled from a plurality of mass produced link members pivotally fastened together by pins or rivets. Each link member is manufactured according to certain preset tolerances. As the link members are assembled into a link system, there is a tolerance accumulation, which may result in an undesirable total tolerance stack up between certain locations of the link system, typically the mounting locations, in one or more orientations of the link system. 
     Such tolerance stack ups may result in an undesirable misfit between mass produced components connected by the link system, which may adversely affect appearance or functionality of the link system itself or that of the finished product into which the link system is assembled. Reduction of this tolerance stack up to within an acceptable range may require that the components be manufactured using more expensive methods or using more expensive equipment than would otherwise be required. Alternatively, this tolerance stack up may be compensated for after assembly, such as by adjustments, requiring extra manufacturing or installation time and expense. 
     Where the link system is used as a hinge to movably mount a lid to an enclosure, the stack up of tolerances in the link system may result in an undesirable misfit between the lid and the enclosure when the lid is closed. Where the lid is a trunk lid of a vehicle and the enclosure is a trunk enclosure of a vehicle, the tolerance stack up can result in an aesthetically undesirable misalignment of the trunk lid with the outer surfaces of the vehicle. In extreme cases, a tolerance stack up could result in a compromised seal between the trunk and the vehicle, which could potentially result in undesired leakage into the trunk enclosure when the trunk is closed. 
     SUMMARY 
     The present application discloses a link system providing a desired spatial relationship in a desired orientation of the link system as well as methods of assembling link systems to obtain the desired spatial relationship. 
     In accordance with one exemplary assembly, a link system is disclosed having a plurality of links each one of the link members being pivotally interconnected to at least one of the other link members at a pivot joint. A first chosen link and a second chosen link have a desired relative positional relationship in a specific orientation. At least one of the pivot joints between one of the links and another of the links may include a first aperture in the one of the link members, a second aperture in the another of the link members overlying the first aperture and axially offset relative to the first aperture, and a fastener capable of deformation such as a rivet extending through the first and second apertures. The fastener may have a first head abutting the one link, a first shank portion passing through the first aperture and having a first longitudinal axis and, a second shank portion passing through the second aperture and a having a second longitudinal axis offset relative to the first longitudinal axis, and a second head abutting the another link. The first longitudinal axis may be axially offset from the second longitudinal axis a distance required to position the one link at the desired position relative to the another link in the specific orientation. 
     In accordance with another exemplary assembly, a method of assembling a link system is provided that may include one or more of the steps of fixturing two selected links to selected relative locations, placing a rivet through a pair of the generally aligned pairs of apertures in two of the links, and compressing (e.g., axially) the rivet to form a head on the backside of the rivet and to deform to conform to the generally aligned apertures to at least partially take up the tolerance stack up between the two selected links. 
     In accordance with another exemplary assembly, a lid hinge assembly may be provided for movably supporting a lid relative to an enclosure where a desired positional relationship between lid and the enclosure is maintained when the lid is closed. The lid hinge assembly could include a lid link capable of being mounted to the lid, an enclosure link capable of being mounted to the enclosure, and a pair of intermediate links. Each of the intermediate links may have an aperture overlying and axially offset relative to an aperture in the trunk link as well as an apertures overlying and axially offset from an aperture in the lid link. The apertures are axially offset predetermined distances providing the desired positional relationship between the lid link and the enclosure link when the lid link is mounted to the lid, the enclosure link is mounted to the enclosure, and lid is in the closed position. In the example, four rivets each extend through a respective pair of offset apertures, each rivet having a first shank portion passing through a first aperture, a second shank portion offset relative to the first shank portion and passing through a second aperture. 
     In a further exemplary assembly, a hinge assembly is assembled by fixturing the links of the hinge assembly with two links in a desired relative relationship. To generally align pairs of apertures in associated links, passing at least one rivet having a shank portion with a first outer diameter portion a second shank portion having a second outer diameter portion smaller than the first outer diameter portion through at least one of the pairs of overlying apertures. Then it is possible to deform the at least one rivet to form at least one pivotal connection between the two selected links using the deformed rivet to fill any longitudinal offset between the apertures and compensate for the tolerance stack ups between the links. 
     The present invention will be more fully understood upon reading the following detailed description in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Referring now to the drawings, illustrative embodiments are shown in detail. Although the drawings represent some embodiments, the drawings are not necessarily to scale and certain features may be exaggerated, removed, or partially sectioned to better illustrate and explain the present invention. Further, the embodiments set forth herein are exemplary and are not intended to be exhaustive or otherwise limit or restrict the claims to the precise forms and configurations shown in the drawings and disclosed in the following detailed description. 
         FIG. 1  is a perspective view of a motor vehicle having a trunk hingedly supported by an exemplary link system, with a trunk lid shown closed in solid line and open in phantom line, and the link system shown only in the open position in phantom line; 
         FIG. 2  is a perspective view of the motor vehicle of  FIG. 1  with the trunk open, the link system being illustrated in an extended configuration; 
         FIG. 3  is an elevational view of the link system of  FIGS. 1 and 2  with the trunk lid and the a portion of the interior wall of the trunk enclosure shown somewhat schematically in a closed position; 
         FIG. 4  is an elevational view of the link system of  FIGS. 1 and 2  with the trunk lid and the a portion of the interior wall of the trunk enclosure shown somewhat schematically in an open position; 
         FIG. 5  is an exploded elevational view of the four links of the link system of  FIGS. 1-4  shown prior to assembly of the link system; 
         FIG. 6  is an elevational view of the four links and four rivets of the link system of  FIGS. 1-4  fixtured for assembly of the link system, the fixture being shown somewhat schematically; 
         FIG. 7  is an enlarged elevational view of region  7  of  FIG. 6 ; 
         FIG. 8  is a sectional view of a representative joint of the link system of  FIGS. 1-3  fixtured and prior to riveting of the joint; and 
         FIG. 9  is a sectional view of the representative joint of  FIG. 8  after the riveting of the joint. 
     
    
    
     DETAILED DESCRIPTION 
     Disclosed herein is a link system  20  and method of assembling a link system for providing close dimensional tolerances in a desired orientation of the link system. In the interest of clarity, not all features of an actual implementation of a link system are described in this specification. It will of course be appreciated that in the development of any such actual illustration, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints that will vary from one implementation to another. 
     Referring now to the drawings wherein like numerals indicate like or corresponding parts throughout the several views, exemplary embodiments of a link system are illustrated. 
     As shown generally in  FIGS. 1 through 4 , a vehicle  10  has a trunk compartment  12  selectively closed by a trunk lid  14 . As best shown in  FIG. 1 , the vehicle  10  further has a right fender  16  and a left fender  18  (shown only in  FIG. 1 ) on either side of the trunk compartment  12 . The trunk lid  14  is hingedly fastened to the vehicle  10  by one or more hinges, such as a link system  20 , described later in detail. As best shown in  FIGS. 3 and 4 , each link system  20  is secured by fasteners  22  and  24  to an inside surface of the trunk lid  14  and by fasteners  28  and  30  to the a mounting surface  26  on the inside of the trunk compartment  12 . In the embodiment shown in  FIG. 2 , the mounting surface  26  is a plate adjacent the inner wall  32  of the trunk compartment  12 . 
     Referring now generally to  FIGS. 3 through 5 , the link system  20  is shown in a retracted orientation corresponding to the closed trunk in  FIG. 3 , in an extended orientation corresponding to an open trunk in  FIG. 4 , and in an exploded view prior to assembly in  FIG. 5 . 
     The link system  10  comprises a plurality of links and fasteners that are secured together such as utilizing the exemplary approach described below. In particular, the exemplary link system  20  includes an upper link member  50  having apertures  52  and  54  for accepting the fasteners  22  and  24  ( FIGS. 3 and 4 ) that fasten the link system  20  to the trunk lid  14 . The link system  20  further includes a lower link member  56  having apertures  58  and  60  ( FIG. 5 ) for accepting fasteners  28  and  30  ( FIGS. 3 and 4 ) that fasten the link system to the vehicle  10 . The link system  20  also includes a first intermediate link member  62  and a second intermediate link member  64 , each extending between the upper link member  50  and the lower link member  56 . The upper link member  50  and the first intermediate link member  62  are provided with apertures  66  and  68  (shown only in  FIG. 5 ), respectively, proportioned to accept a fastener  70 . In an exemplary approach the fastener is capable of selective deformation and is illustrated as a rivet  70  as shown in  FIGS. 3 and 4  to pivotally secure the upper link to the first intermediate link. Similarly, the upper link member  50  and the second intermediate link member  62  are provided with apertures  72  and  74 , respectively, (shown only in  FIG. 5 ) proportioned to accept a fastener such as a rivet  76  as shown in  FIGS. 3 and 4  to pivotally secure the upper link member  50  to the first intermediate link member  62 . The lower link member  56  and the first intermediate link member  62  are provided with apertures  78  and  80 , (shown only in  FIG. 5 ) respectively, proportioned to accept a fastener such as a rivet  82  to pivotally secure the lower link member  56  to the first intermediate link member  62  as shown in  FIGS. 3 and 4 . Finally, the lower link member  56  and the second intermediate link member  64  are provided with apertures  84  and  86 , respectively, (shown only in  FIG. 5 ) proportioned to accept a fastener such as a rivet  88  to pivotally secure the upper link to the first intermediate link as shown in  FIGS. 3 and 4 . 
     There are manufacturing tolerances associated with each of the components of the link system. There are manufacturing tolerances, for example, in the x-axis distance between apertures  58  and  80  ( FIG. 5 ) which are the respective mounting points for fastener  28  and rivet  82  ( FIG. 3 ) of the lower link member  56 , shown in  FIG. 3  as distance a. There are further manufacturing tolerances in the x-axis distance between apertures  60  and  80  ( FIG. 5 ) which are the respective mounting points for fastener  30  and rivet  82  ( FIG. 3 ) of the lower link member  56 , shown in  FIG. 3  as distance b. Similarly, there are manufacturing tolerances in the x-axis distance c between apertures  66  and  78  ( FIG. 5 ) of intermediate link member  62  through which rivets  70  and  82  are passed ( FIG. 3 ) is also subject to manufacturing tolerance. 
     Moreover there is a tolerance stack up in the y-axis direction. For example, y-axis distances d and e of  FIG. 3  between apertures  80  for rivet  82  and mounting apertures  56  and  60 , respectively, for fasteners  28  and  30  are associated with tolerances in the manufacturing of the lower link member  56 . Additional tolerance is associated with the thickness of the material, shown as distance h in  FIG. 3 , and with the y-axis distance g between surfaces of the upper link member  50  and the center of aperture  68  ( FIG. 5 ) through which rivet  70  is provided. The y-axis distances f between apertures  66  and  78  ( FIG. 5 ) of intermediate link member  62  through which rivets  70  and  82  are passed ( FIG. 3 ) is also subject to manufacturing tolerance. Similarly, the distances between the apertures  72  and  84  of intermediate link member  64 , between apertures  68  and  74  of upper link member  50 , and between apertures  80  and  86  of lower link member  56  are each subject to a manufacturing tolerance. There are also tolerances associated with the rivets  70 ,  76 ,  82  and  88  and further tolerances due to the riveting process. When the link system is assembled, these tolerances may accumulate and each provide an x-axis and y-axis contribution, to a total tolerance stack up between the trunk lid  14  and the vehicle  10 , which will differ depending on the orientation of the link assembly. 
     These tolerances accumulate during the manufacturing and assembly of the link system  20  to result in an unwanted tolerance stack up between the relative location of the apertures  52  and  54  in the upper link member  50  and the apertures  58  and  60  of the lower link member  56 . When the link assembly  20  is subsequently assembled to the vehicle  10 , this tolerance stack up can result in an undesirable misalignment between the trunk lid  14  and the vehicle  10  in the closed orientation of the trunk lid, unless this tolerance accumulation is accommodated in the manufacturing or assembly process. 
     More particularly, as shown in  FIG. 1  in solid line, when the trunk lid  14  is closed, the upper surface  34  of the trunk lid  14  is disposed adjacent the upper surfaces  38  and  40 , respectively, of the right and left fenders  16  and  18 . It is desirable for aesthetic, aerodynamic and trunk compartment sealing purposes to position the trunk lid as accurately as possible relative to the fenders  16  and  18  of the vehicle  10 . It is therefore desirable to hold the link system  20  to close tolerances. More particularly, it is desired that the tolerance stack up from manufacturing tolerances be minimized or adjusted for in the orientation of the link system corresponding to the closed trunk condition shown in  FIG. 3  as the retracted orientation. 
     On the other hand, as shown in  FIG. 1  in phantom line and  FIGS. 2 and 4  in solid line, the tolerance stack up in the link system  20  is typically less important when the link system is in the extended position with the trunk lid  14  open relative to the trunk compartment  12 . It is therefore desirable to assemble the link system  20  in a manner that holds the assembly of the vehicle  10 , trunk lid  14  and link system  20  to close tolerances in the retracted orientation of the link system. 
     Referring now to  FIG. 6  and  FIG. 7 , components of the link system  20  are shown in a fixture system  100  (shown schematically) for securing the upper link member  50  and the lower link member  56  in temporarily fixed relative locations corresponding to their desired relative locations when assembled. As illustrated, the links are fixtured in a desired position in a desired orientation of the link assembly by being secured at locations corresponding to the mounting locations of the exemplary link system. More particularly, the link assembly illustrated is fixtured in the orientation corresponded to trunk lid  14  being closed, or as close to that position as is reasonably practical, and is fixtured in that position at the mounting locations where the fixture interconnects with the vehicle  10  and the trunk lid  14 . 
     As best shown in  FIG. 6 , the upper link member  50  is secured in the fixture  100  against a fixturing element  102  that simulates the trunk  14 . The upper link member  50  is secured in the selected location by being secured, for example by fasteners  22 ′ and  24 ′ in a manner similar to the manner in which it will subsequently be secured to the trunk lid  14  and using the same mounting apertures  52  and  54  which will be used for mounting the upper link member  50  to the trunk lid  14 . The fasteners  22 ′ and  24 ′ may each include a post extending from the fixturing element through the mounting apertures  52  and  54  and a locking component such as a nut or a pin engaging the post to secure the upper link member  50  in position during assembly. The upper surface  92  of the upper link member  50  may abut the fixturing element  102  in a manner similar to the manner in which the upper link will subsequently abut the trunk lid  14  when the link system  20  is installed in a vehicle  10 . 
     The lower link member  56  is similarly secured to the fixture  100  by being placed adjacent a fixture element  104  having posts  28 ′ and  30 ′ which extend through mounting apertures  58  and  60  which will subsequently be used with fasteners  28  and  30  for mounting the lower link member  56  to the vehicle  10 . The lower link member  56  may be secured in a position abutting a surface of the fixture element  104  by a locking component (not shown) such as a nut or a pin engaging the posts  28 ′ and  30 ′ to secure the upper link member  50  in position during assembly of the link system  20 . 
     The fixture  100  is designed and manufactured to maintain the upper link member  50  and the lower link member  56  their respective desired locations in the preferred orientation corresponding to a closed trunk lid  14 . Furthermore, the fixture  100  holds the upper link member  50  and lower link member  56  in these desired locations to within an acceptable tolerance which is smaller than the tolerance stack up inherent in the mass produced components of the link system  20 . 
     Intermediate link member  62  is positioned by fixturing element  106  (shown schematically) to be generally positioned with the apertures  66  and  78  aligned approximately with the apertures  68  and  80 , respectively, of the upper link member  50  and the lower link member  56  for subsequent acceptance of rivets. Intermediate link member  64  is similarly positioned by fixturing element  108  (shown schematically) to be generally positioned with the apertures  72  and  84  aligned approximately with the apertures  74  and  86 , respectively, of the upper link member  50  and the lower link member  56 . 
     The positioning of the intermediate links  62  and  64  relative to the upper link member  50  and the lower link member  56  is held to a predetermined tolerance, but will not result in perfect alignment of the apertures. Since the upper and lower links  50  and  56  are held in their respective relative desired positions determined by the fixturing elements  102  and  104 , respectively, the tolerance stack up that otherwise would accumulate between the mounting location of the upper link member  50 , defined by the apertures  52  and  54 , and the mounting location of the lower link member  56 , defined by the apertures  58  and  60  will be reflected in a slight misalignment between the pairs of overlying apertures in the respective links. This is best shown by way of example at  110  and  112  in  FIG. 7 . 
     Refer now to  FIG. 8 , showing a cross-section through a exemplary pair of apertures  120  and  122  in representative links  124  and  126 , respectively, illustrative of any or all of the overlying pairs of apertures in the link system  20  described above. The misalignment of overlying apertures resulting from tolerance stack up is illustrated in  FIG. 8  by the misalignment of the respective longitudinal axes  128  and  130  of the exemplary apertures  120  and  122 . The misalignment of the longitudinal axis is the result of the tolerance stack up described above and is at least partially taken up the riveting process described below. 
     An exemplary rivet  134  is provided for insertion in the pair of exemplary apertures  120  and  122  for riveting the representative links  124  and  126  together. 
     A bushing  140  may be fitted in the aperture  120 . The busing  140  has an aperture  142  and provides a bearing surface for the exemplary rivet  134  to facilitate the pivotal movement between the representative links  124  and  126  after the components have been riveted together. The bushing  140  also includes outwardly oriented flanges  144  and  146  cooperating with opposing faces of the representative link  124  to secure the bushing to representative link  126 . The outwardly oriented flange  146  also provides a bearing surface for the representative link  126 , further facilitating the pivotal movement between the representative links  124  and  126  after the components have been riveted together. 
     The exemplary rivet  134  has a head  148  having an outer diameter substantially larger than the inner diameter of the aperture  142  in the bushing  140  so as to permit the head to abut the surface of the link  124 . The exemplary rivet  134  further has a first shank portion  150  having an outer diameter j no greater than the inner diameter l of the aperture  142  in the bushing  140  so that it will pass through the aperture and will permit pivotal movement of the representative link  124 . The first shank portion has approximately the same length p as the length r of the aperture  142 . The exemplary rivet  134  also has second shank portion  152  having a diameter k no greater than the inner diameter m of the exemplary aperture  122  in the representative link  126  and having a length q significantly greater than the length s of the exemplary aperture  122  to provide extra material for the deformation of the exemplary rivet described below. The diameter k of the second shank portion  152  is illustrated smaller than the diameter j of the first shank portion  150  for reasons that will be described below. 
     As shown in  FIGS. 8 and 9 , an anvil  160  is provided on the backside of the exemplary aperture  122  in the representative link  126  for use in the riveting process. The anvil  160  includes a recess  161  having a width n to form a head on the backside of the rivet, as will be described shortly. The anvil  160  may be part of fixture system  100  or may be part of a riveting tool, not shown. 
     As shown in  FIG. 9 , illustrating an exemplary pivot joint formed between the representative links  124  and  126  using the exemplary rivet  134 , the exemplary rivet is positioned in the apertures  142  and  122  or is driven through the apertures  142  and  122  by a tool, not shown, abutting the head  134 . With exemplary rivet  134  secured in position, for example, by a tool, not shown, pushing the head  148  against the representative link  124 , the anvil  160  is driven against the second shank portion  152 . The shank portion  152  is thereby deformed by pressure into a new configuration shown in  FIG. 9  as formed rivet  134 ′ having a shortened second shank portion  152 ′ and a second head  162 , as described below in detail. The head  148 ′ is only slightly deformed by the action of the riveting tool and the anvil. 
     It will be appreciated that for some installations, the anvil  160  may, alternatively, be held in a stationary position against the representative link member  126  and the rivet  134  may be driven through the apertures  142  and  122  and deformed into the recess  161  in the anvil  160  in a single operation. 
       FIG. 9  illustrates the deformations that occur as the rivet  134  is deformed into formed rivet  134 . The portion of the second shank portion  152 ′ within the exemplary aperture  122  bulges to engage the material of the representative link  126  and deforms eccentrically to accommodate the offset between the longitudinal axes  128  and  130  of the apertures  120  and  122 . A portion of the offset of the longitudinal axes  128  and  120  may also be accommodated by asymmetrical deformation of the material of the representative link  126  around the aperture  122 , depending on the relative hardness of the components. While the first and second shank portions may have the same outer diameter, the outer diameter k of the second shank portion  152  is illustrated smaller than the outer diameter j of the first shank portion  150  in order to limit the deformation of the first shank portion, which is intended to rotate freely in the bushing  120 , while facilitating the deformation of the second shank portion to fill the second aperture  122  to take up at least a portion of the tolerance stack up. By providing the second shank portion with a reduced outer diameter relative to the first shank portion, then, the first shank portion  150 ′ is also slightly transformed by the riveting tool but remains sufficiently free in the aperture  142  to permit pivoting of the links system  20  about the longitudinal axis  128  of the aperture  142  in the bushing  140  while the second shank portion  152 ′ is significantly deformed. 
     As a result of the deformation process conforming the shank portions to the apertures, the formed rivet  134 ′ will have a first shank portion  150 ′ with a longitudinal axis  128  offset from the longitudinal axis  130  of the second shank portion  152 ′. Further, as a result of the deformation process, the formed rivet  134 ′ and representative links  124  and  126  form a pivot joint for the link system that pivots about longitudinal axis  128 . 
     The portion of the second shank portion  152 ′ that extends beyond the exemplary aperture  122  is deformed into the recess  161  in the anvil  160  to form a head  162  on the backside of the representative link  126 . 
     Appropriate selection of materials for the bushing  140 , the links  124  and  126 , and the rivet  134  will facilitate the desired formation of the pivot joint having the characteristics described above. For example, the representative links  124  and  126  and the bushing  140  should be formed of a material that is stronger than the material used for the rivet  134  so that the pressure of the riveting operation will be substantially result in deformation of the rivet rather than the other components of the pivot joint. For many applications, such as the trunk hinge system illustrated in  FIGS. 1 through 4 , a n appropriate steel, such as  1018 , may be used to facilitate deformation and flow of material at the time of riveting, while providing a durable pivot joint for long term use. However, other materials such as lead could be used depending on the loading and the environment experiences by the link system. 
     Referring again to  FIGS. 6 and 7 , the process described above may be used for each of the rivets  70 ,  76 ,  82  and  88 . The links are thereby pivotally connected together maintaining the desired relationship between the upper link member  50  and the lower link member  56  in the desired orientation, with the undesirable portion of tolerance accumulation taken up by the deformation of the rivets, as illustrated by the asymmetrical relationship between the first shank portion  152 ′ and the second shank portion  154 ′ created during the riveting process of the exemplary joint of  FIG. 9 . 
     More particularly, the manufacturing tolerances described above with reference to  FIGS. 3  results in a tolerance stack up that may be at least partially compensated at each of the pivot joints of the link system  20  by using the process described above. When the links  50 ,  56 ,  62  and  64  are secured in the fixture  100 , the tolerance stack up will result in each of pairs of overlying apertures to be riveted together, such as apertures  66  and  68 , to be offset as shown in  FIG. 7  at  112  and reflected in the offset longitudinal axes  128  and  130  for the representative pivot joint shown in  FIGS. 8 and 9 . The offsets of each of the pairs of overlying apertures must together take up the entire tolerance stack up of the components of the link system  20 . To do so the rivets  70 ,  76 ,  82  and  88  must be able to be inserted into their respective pair of apertures prior to the riveting process, even when the dimensions of the components are at the extremes of the tolerance ranges and the apertures are longitudinally offset by the maximum amount. 
     This requirement may be satisfied by dimensioning the apertures in the link system  20  so that they will be large enough to pass the rivets  68 ,  72 ,  82  and  88  through all of the respective pairs of generally aligned apertures, even at the maximum offset. This may be accomplished, for example, by assuring the inner diameter m ( FIG. 8 ) of the aperture  122  of each representative link member  126  is larger than the outer diameter k of the second shank potion  152  of each rivet  134  by an amount sufficient to assure that the rivets will together take up the entire stack up of tolerances in the manufacture of the components of the link system  20 . 
     It is possible, alternatively, to accomplish the above described dimensional relationship by either modifying the inner diameter of the apertures or by modifying the outer diameter of the rivet. Therefore, this requirement may alternatively be satisfied by dimensioning the rivets  68 ,  72 ,  82  and  88  so that the shank portions  150  and  152  will be small enough to pass through the respective pairs of generally aligned apertures even at the maximum offset. This may be accomplished, for example, by assuring the outer diameter k ( FIG. 8 ) of the second shank portion  152  of each rivet is smaller than the inner diameter m of the second aperture  122  of each of the pairs of generally aligned apertures by an amount sufficient to assure that the rivets will together take up the entire stack up of tolerances in the manufacture of the components of the link system  20 . 
     It will be appreciated that the link system  20  and the method of manufacturing the link system  20  provides a precise relative positioning of the trunk lid  14  in a chosen orientation, in this case the orientation where the trunk lid  14  is closed and it is desirable to have a proper alignment of the trunk relative to the fenders  16  and  18  of the vehicle. This is accomplished preferably by fixturing the hinge assembly  20  in the orientation corresponding to the closed trunk lid position with the links that connect to the trunk lid  14  and to the vehicle  10  in the precise relative positions that they will be in when the link system is installed in a vehicle and forming pivot joints between the links of the link system that maintain this precise relationship. It will be appreciated that, as a result of the method used, the tolerance stack up from manufacturing tolerances in the components are fully compensated for in that chosen orientation of the link system. However, in other orientations of the link system  20 , such the fully open trunk orientation of  FIG. 1 . there is no compensation for the tolerance stack up, since there is less concern for the precise positioning of the trunk lid. In fact, since the links of the link system  20  will pivot about longitudinal axes determined by the manner in which the rivets deform while being fixtured in the chosen orientation, the effect of the tolerance stack up in orientations other than the chosen orientation may be amplified. This is acceptable for uses of the link assembly  20  such as that illustrated since there is significantly less concern about the precise positioning of the links or the components, such as the trunk lid, to which the links are attached in orientations other than the chosen orientation. 
     It should be noted that for some link systems, fixturing in the fully closed position may not be practical for geometric reasons. For example, the apertures for one of the rivets may be blocked by links or other components in the fully closed position. For such link systems, it may be more practical and advantageous to fixture the link system in a position reasonably close to the fully closed position. In one exemplary embodiment, the riveting may occur, for example, with the link system open an amount required by geometric or other considerations, such as approximately 5 degrees away from the fully closed position to facilitate one or more of the riveting operations. While this orientation may result in a small departure from the precision obtainable in the fully closed position, it may, for some applications, still result in a sufficiently accurate positioning of the links for practical purposes. For such applications, the desired orientation for fixturing may not be the most critical orientation of the link system, then, but instead a practical orientation that will deliver a finished link system that is held to a close tolerance in not only the desired orientation but in other orientations. 
     It should be noted that the selection of the apertures having a bushing or otherwise having a bearing surface for the rivet may determine the direction in which riveting should occur since the bearing surface may best accommodate rotation of the link system if the bearing surface cooperates with a portion of the shank of the rivet that is not significantly deformed. In the exemplary rivet described above, the shank portion  150  furthest from where the head  162  is formed deforms less than the shank portion  152  closer to the head  162 . It should further be noted that the selection of which aperture has the bearing surface determines the center of rotation for the relative movement of the two link members associated with the aperture. 
     For some applications, it is possible that the link assembly  20  will be in a more precise position, even in the open orientation, than would be likely using standard riveting techniques. This is true particularly if the apertures chosen for the bearing surface, and therefore the apertures that define the center of rotation of the link assembly, are optimally selected to reduce the tolerance stack up as the link assembly moves from the fixtured orientation to other orientations. For the link assembly  20  illustrated in  FIGS. 1-4 , providing the bearing surface on the apertures  68 ,  74 ,  80  and  86  in the upper link member  50  and the lower link member  56 , respectively, permits the link system to pivot on points more closely tied to the mounting points of the upper and lower link members, as compared to providing the bearing surface on the apertures  66 ,  72 ,  78  and  84  in the intermediate link members  62  and  64 . 
     However, it may not be possible or practical, for some applications, to choose the optimum apertures for defining the centers of rotation of the link assembly  20  for a variety of reasons. For some applications, the geometry of the link system  20  may pose challenges for the placement of riveting equipment and thereby may dictate the direction in which a particular rivet will need to be driven. For other applications, economic considerations may lead to a decision to perform all riveting operations through the assembly in the same direction, even where that differs from the choice that would be made to optimize the pivot points of the link assembly. 
     In those installations where the optimum selection of apertures to define the axis of rotation is chosen, the tolerance stack up may be significantly reduced or eliminated in all orientations of the link system. In those installations where the optimum selection of apertures to define the axis of rotation may not be chosen, the tolerance stack up will still be significantly reduced or eliminated in the orientation in which the link system is fixtured for riveting. However, the tolerance stack up could be amplified in the other orientations. As described above, this may be acceptable for link systems such as those used for trunk assemblies since the positioning of the trunk lid is not as critical when the trunk is opened as when it is closed. 
     It is to be understood that the above description is intended to be illustrative and not restrictive. Many alternative approaches or applications other than the examples provided would be apparent to those of skill in the art upon reading the above description. For example in the embodiment illustrated in the drawing and described above, the fixturing of the link system  20  is carried out in the orientation of the links corresponding to the trunk being in the fully closed position. For other embodiments, another relative orientation of links may be critical. The scope of the invention should be determined, not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The present embodiments have been particularly shown and described, which are merely illustrative of the best modes. It is anticipated and intended that future developments will occur in the arts discussed herein, and that the disclosed systems and methods will be incorporated into such future examples. 
     It is intended that the following claims define the scope of the invention and that the method and apparatus within the scope of these claims and their equivalents be covered thereby. This description should be understood to include all novel and non-obvious combinations of elements described herein, and claims may be presented in this or a later application to any novel and non-obvious combination of these elements. Moreover, the foregoing embodiments are illustrative, and no single feature or element is essential to all possible combinations that may be claimed in this or a later application. 
     All terms used in the claims are intended to be given their broadest reasonable constructions and their ordinary meanings as understood by those skilled in the art unless an explicit indication to the contrary is made herein. In particular, use of the singular articles such as “a,” “the,” “said,” etc. should be read to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary. 
     In sum, it should be understood that the invention is capable of modification and variation and is limited only by the claims presented below.