Abstract:
A link assembly forming a 6 bar linkage is integrally combined with a spring having a laterally coiled strand to form a hinge that is particularly well adapted to be installed in a small footprint. Such a unit is well adapted for installation within a peripheral channel of a vehicle body opening and to prop the closure in its open position. The present invention also provides a method for reducing packaging footprint of a vehicle closure hinge by integrating the 6 bar linkage with the laterally coiled strand, and selecting a strand shaping to reduce radial dimension of the coil and the coil cross-section while maximizing the radial dimension of material in the strand.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to spring biased vehicle closure hinges having a laterally coiled spring in integral construction with a link assembly having a reduced footprint for improved packaging in restricted areas, for example, the peripheral channel adjacent to a vehicle opening such as a rear trunk compartment.  
         [0003]     2. Background Art  
         [0004]     Many previously known vehicle closure hinges such as those used for engine compartment hoods and trunk lids often include spring biasing to assist displacement of the heavy panel which is displaced about a pivot axis at one end of the panel. However, a spring biasing assist force sufficient to maintain the closure in a fully open position is often provided by additional structure such as a prop rod, gas struts or the like to resist closure of the closure panel by the weight of the panel acting in a moment arm about the pivot axis or force transfer through a linkage.  
         [0005]     One method to increase the spring biasing has been to use the torsion rods that can be routed across the car. However, while such spring biasing can be strong enough to resist closure, since the entire length of the torsion rod provides spring biasing force, the elongated torsion rods can obstruct and form a substantial impediment to the access through the opening or within the compartment covered by the closure panel. Other improvements to spring design, such as gas powered struts or powerful springs often require multiple installation steps since the spring biasing force unit must be separately installed to assist a conventional hinge structure. Such improvements substantially increase the difficulty of production, rendering the use of such components prohibitively expensive because they add production steps as well as additional pieces and mass to the vehicle. In the case of a gas strut power source, in a closed position the line up force in the strut is directed to the hinge pivot, thus forcing the pivot to endure high loading that shortens useful life of the original installation. Also, the life of a gas strut is both time-dependent and cycle-dependent, making it much less durable than a steel spring.  
         [0006]     Moreover, once the spring force has been determined for a particular application, the hinge designs may not be readily incorporated into other vehicles having differently sized, weighted or balanced mass or center of gravity than the installation for which it was designed. As a result, the alternative assemblies may need redesigned linkage and/or biasing structures for each particular closure panel type, thereby substantially multiplying the number of assemblies and production pieces that must be made and inventoried in order to accommodate production and repair of the vehicles despite similar hinge needs and arrangements in the various openings of different vehicle styles.  
         [0007]     A previously known attempt to address the problems discussed above involves the use of a single pivot arm as part of a four bar link assembly and integral clock spring. However, while the clock spring may provide substantial flexibility in the design and spring biasing force applied to a hinge mechanism, such springs require an extremely large envelope vertically as well as fore-and-aft to accommodate the four bar linkage and the coil spring. Moreover, the previous designs of this type have been complex requiring numerous parts and assembly operations, the addition of parts rendering the hinge relatively heavy, and thus have not found favor in many production applications due to the large expense compared to more conventional systems.  
       SUMMARY OF THE INVENTION  
       [0008]     The present invention overcomes the above-mentioned disadvantages by providing a reduced footprint hinge construction for vehicle closure by combining a laterally coiled spring with a Watt 6 bar linkage that provides large travel displacement of the vehicle closure from closed to open position with spring biasing. The linkage resists lift-off of the leading edge or pivoted edge of the closure by rotating the deck lid about the leading edge location for a significant percentage of motion along the displacement path. Such linkage prevents the pivoted edge from being pushed off its seal by the forces of the coil spring when the closure is in its closed position.  
         [0009]     In the preferred embodiment, the six bar linkage and integral spring combination is mounted in a structural gutter peripherally formed around the opening in the vehicle body. The complexity of manufacturing the various links in the linkage is reduced by matching the design of at least two of the bars in the six bar link so that separate tooling for manufacturing each link is not required. Moreover, the packaging size of the spring may be modified by shaping the cross-section of the strand forming the coil as well as by modifying the number of coils, the diameter of the coils and the thickness of the strand. As a result, the present invention provides a method for reducing the footprint in a manner that is particularly well adapted for mounting the mechanism in the peripheral gutter of a vehicle body compartment such as a trunk.  
         [0010]     As a result, the present invention provides a method and apparatus for reducing packaging requirements for the vehicle closure hinge and providing it with spring biasing assist for opening and maintaining the open position of the closure. In particular, the mechanism can be designed to support the closure in a fully open position without external gas filled struts, prop rods or the like that would otherwise need to be packaged in the vehicle. Moreover, the vehicle closure hinge is not subject to performance variation under changing ambient conditions and weather, eliminates lift-off of the leading edge of the closure when in its closed position, and avoids obstruction of both the vehicle opening and the compartment accessed through the opening. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The present invention will be more clearly understood by reference to the following detailed description of the preferred embodiment when read in conjunction with the accompanying drawing, in which like reference characters refer to like parts throughout the views, in which:  
         [0012]      FIG. 1  is a perspective view of a portion of a vehicle body with the closure mounted by a hinge assembly with integral spring constructed according to the present invention;  
         [0013]      FIG. 2  is an opposing perspective view similar to  FIG. 1  and also showing the hinge in its open position;  
         [0014]      FIG. 3  is an enlarged perspective view of a portion of the device shown in  FIG. 2 ;  
         [0015]      FIG. 4  is an enlarged perspective view of portion of  FIG. 1 ;  
         [0016]      FIG. 5  is an enlarged perspective view similar to  FIG. 4  but showing the hinge in its closed position;  
         [0017]      FIG. 6  is an enlarged perspective view similar to  FIG. 3  but showing the hinge in its closed position; and  
         [0018]      FIG. 7  is an enlarged, partially section view of a portion of the assembly. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0019]     Referring first to  FIG. 1 , a vehicle body  12  is as shown including a vehicle closure panel  14 , such as a deck lid panel, adapted to close over an opening  18  in a body structure  16 , the opening  18  providing access to a compartment  20  formed within the body structure  16 . The closure panel  14  is secured at one end by a hinge mechanism  22  comprising a pair of hinge sets  24  mounted at spaced positions on a panel  14  near a leading or pivot edge  26 . The opposite, trailing, or latch edge of the panel  14  include a latch mechanism for latching the panel  14  in the closed position over the opening  18  in a well-known manner.  
         [0020]     In the preferred embodiment, the opening  18  is peripherally defined by a sheet metal structure  16  formed as a gutter trough  28 . The peripheral gutter  28  adds strength to the body structure  16  adjacent the opening as well as a rain trough for controlled routing of rain water for draining. In the preferred embodiment, obstruction of the access opening  18  and the compartment  20  is minimized by locating each of the hinge sets  24  in the gutter  28 .  
         [0021]     In the preferred embodiment, each hinge set  24  includes a Watt 6 bar link A 98  assembly  25  integrally constructed with a laterally coiled spring  102  for biasing members of the link assembly  25  to raise the panel  14  to its open position as shown in  FIGS. 1 and 2  and described in greater detail below. The selection of a Watt 6 bar linkage is appropriate where wide open position or large range of motion is desired, although other linkage isomers and isomer variations may be selected without departing from the method of the present invention.  
         [0022]     As best shown in  FIG. 1 , the gutter  28  includes an expanded corner area receiving linkage assembly  30 , the integral combination of link assembly  25  and spring  102 . The assembly  30  is preferably coupled at one edge of the gutter, to allow a laterally coiled spring  102  extending outwardly from the assembly. The diameter of the coils, the number of coils and the thickness of the strand of the coil can be adjusted as desired to ensure sufficient torsion characteristics to operate the link assembly  30 . In addition, as shown in  FIG. 7 , the shape of the strand may be modified to enhance or otherwise adjust the strength of the spring without changing size of the envelope. For example, the strength within the package may be maximized without expanding the envelope by shaping the strand as shown in  FIG. 7  as rectangular in cross-section so that the radial width of the material in the coil is maximized for strength where the diameter of the coils or the number of coils or both must be limited for example, to fit within the gutter area.  
         [0023]     Referring now to  FIGS. 3 and 4 , the link assembly  30  includes a body mount bar  32  having mounting flanges  34  and  36  that receive fasteners such as the bolts  38  ( FIG. 4 ) shown in  FIG. 1 . The bar  32  also includes spaced pivot pin anchors  39  and  40  adapted to receive pivot pins  42  and  44 , respectively.  
         [0024]     The link assembly  30  also includes a closure mount bracket  46  with spaced mounting lands  48  and  50  ( FIG. 3 ) for receiving mounting fasteners  52  and  54 , respectively, as shown in  FIG. 1 . A link flange  56  on the closure mount  46  includes pivot supports  58  and  60  adapted to receive pivot pins  62  and  64 , respectively.  
         [0025]     The pivot pins  62  and  64  are preferably formed as rivets so as to pivotally engage an anchor for links  66  and  68 , respectively. Pivoted end  70  of the link  66  is spaced apart from an opening receiving a pivot pin  72 , that similarly engages and permits pivotal movement between the link  66  and the end  74  of a pivot link  76 . The link  76  includes a pivot land  78  spaced from the pivot end  74  between the end  74  and the opposite end  80 . The pivot land  78  is adapted to receive a pivot pin  82  while the pivot end  80  receives a pivot pin  44  at the pivot land  40 . The pivot pin  82  is secured to pivotally secure intermediate portions of the link  68  and the link  76  together. Second pivoted end  84  of the link  68  is pivotally engaged with a pivot land  86  on a link member  88  by pivot pin  85 . The other end of the link member  88  includes a pivot land  90  (shown in hidden line in  FIG. 6 ) receiving the pivot pin  42  engaged in the body mount  32 .  
         [0026]     Preferably, the link member  66  and the link member  88  are formed from the same tooling so that two pieces of the link can be made without unduly increasing the cost of making the numerous links of the link assembly  25  and integral assembly  30 . Accordingly, the land  74  remains unused in the link  88  whereas the land  86  remains unused in the link  66 . Moreover, both members  66  and  88  include an extended end portion  96  opposite the end portion  70 , adapted to support the stem  92  carrying a bumper  94  positioned to press against the edge of the link member  76  when the linkage  25  is extended to the open position of the closure panel. Preferably, the stem is threaded and threadably engaged in the end  96  of the link  66  so that the distance from the bumper can be adjusted to adjust the open position of the hinge. Of course, the end  96  remains unused in the piece used as link  88  in the mechanism  25 . In addition, the link  88  carries a tab  98  that can be wrapped to capture end of the coil spring  102  as shown at  100  in  FIGS. 4 and 6 .  
         [0027]     The link assembly  25  is biased by attaching a laterally coiled spring  102  formed from the single strand of material, for example steel, wrapped so that the coils are adjacent to each other and extend laterally from one coil end to a second coil end. The strand positioned at the second coil end is then extended in the direction along the axis of the coil toward the first end, preferably through the center of the coil. While the first end of the coil spring  102  adjacent the body mount  36  is wrapped in the flange  106 , ( FIG. 4 ) between the mounting lands  32  and  34  on the mount member  36 , the second end of the strand returned toward the first end of the coil is then wrapped in a curled flange  100  formed by the tab  98 . The coils in the spring  102  therefore impose spring biasing force between the end  108  and the end  104  substantially in the plane of displacement defined by the pivot pins  42 ,  44 ,  62 ,  64 ,  72 ,  82  and  85  of the assembly  25 .  
         [0028]     The vehicle closure hinge provides closure opening torque between the body closure bracket  46  and the body mount  36 , and the center of rotation of the drive link in this case link  88 , is positioned so that maximum room is allowed in the gutter for the largest possible spring. Moreover, the spring force can be adjusted as necessary to adjust for different masses and centers of gravity of closures, preferably by adjusting only dimensions of the structure of the spring, such as the diameter of coil or the number of coils in the winding, the size of the strand, and even adjusting the material mass of the spring by shaping the strand within fixed packaging size. In addition, the manufacturing cost is reduced despite the multiple bar construction of the link assembly, particularly where A single bar design can be used in two different locations within the multiple link assembly. Moreover, the spring assist component is integral with the hinge assembly and substantially reduces the package size and footprint of the hinge mechanism. Accordingly, the present invention provides additional functionality with less obstruction of vehicle compartments or the opening providing access to the compartment. The invention also reduces the number of components to be assembled into the vehicle by providing a single integral unit with a wide range of motion for the closure.  
         [0029]     Having thus described the present invention, many modifications will become apparent to those skilled in the art to which it pertains without departing from the scope and spirit of the present invention as defined in the appended claims.