Abstract:
A linking arm assembly incorporating an improved connection between an elongated rod portion and an engagement element such as a ball stud or the like adapted to join the linking arm to another structure. The linking arm assembly may incorporate an improved ball and socket connection. The socket may include an arrangement of flexible rib elements that are compressed when the ball stud is inserted so as to bias against the ball during use. Accordingly, a potentially loose condition may be avoided thereby reducing the possibility for noise or failure over time.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This non-provisional application claims the benefit of, and priority from, U.S. Provisional Application 61/768,754 filed Feb. 25, 2013. The contents of such provisional application and any other patent documents referenced in this application are hereby incorporated by reference in their entirety as if fully set forth herein. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates generally to a linking arm assembly, and is more particularly directed to a linking arm assembly having an improved operative connection between a rod portion and an engagement element such as a ball stud or the like adapted to join the linking arm to another structure. 
       BACKGROUND 
       [0003]    In many operational environments one or more linking arm assemblies may be operatively connected to a structure for use in monitoring the position of that structure relative to a defined reference position. In many of these linking arm assemblies, a rod extends between a pair of socket heads or other attachment elements at either end of the rod. The attachment element at one end of the rod is attached to a ball stud or other engagement element at the structure to be monitored, and the attachment element at the other end is operatively connected to a reference structure or is allowed to articulate in a defined manner. The rod may include one or more sensors which monitor the relative positions of the ends. Changes in spacing and/or relative position of the ends can thus be monitored, thereby indicating changes in position. The linking arm assembly is not generally required to carry a significant load. However, the linking arm assembly may be subjected to substantial vibration and high frequency articulating movement during use. Such linking arm assemblies may be used in conjunction with a vehicle computer to monitor headlight leveling, suspension ride height and the like. By way of example only, a linking arm assembly in accordance with the present disclosure may find application as a vehicle ride height sensor linkage. Such a linkage establishes a connection between the vehicle&#39;s moveable suspension and a sensor, such as a wheel sensor or the like, which provides position information to an electronic control unit. Of course, such assemblies may likewise be used for any number of other purposes as well. 
         [0004]    In some prior linking arms, establishing and maintaining a secure connection between the linking arm and the attached socket structures has required relatively complex assembly practices. Accordingly, a linking arm assembly which promotes secure connection between components while reducing the complexity of the assembly process represents a useful advancement over the current art. 
       SUMMARY OF THE DISCLOSURE 
       [0005]    The present disclosure supplies advantages and alternatives over the prior art by providing a linking arm assembly incorporating an improved connection between an elongated rod portion and an engagement element such as a ball stud or the like adapted to join the linking arm to another structure. The linking arm assembly may incorporate an improved ball and socket connection incorporating a compression socket adapted to surround a proximal portion of a ball stud. The socket may include an arrangement of surfaces inside the socket that are compressed when the ball of a ball stud is inserted so as to continuously bias against the ball during use. The pre-compression aids in centering the ball within the socket. In addition, the spring biasing provides adjustment for diameter variations between the ball and socket due to manufacturing tolerances or wear over time. Accordingly, the joint will avoid a potentially “loose” condition thereby reducing the possibility for noise or failure over time. 
         [0006]    In accordance with one exemplary aspect, the present disclosure provides a linking arm assembly adapted to receive and retain a ball stud. The assembly includes an elongated insertable rod including a terminal end with a plurality of radially projecting, spaced-apart surface ribs disposed adjacent the terminal end. The surface ribs define raised surfaces with an intermediate depression between the surface ribs with the terminal end projecting outboard away from the surface ribs. The assembly further includes at least a first socket head of unitary molded construction adapted for press-fit attachment to the terminal end of the rod. The socket head includes a socket cradle, a resilient proximal body segment extending away from the socket cradle in a first direction, and a distal collar segment extending away from the socket cradle in a second direction transverse to the proximal body segment. The proximal body segment includes an interior channel adapted to receive the terminal end of the rod. The distal collar segment defines a stud insertion passageway substantially aligned with a concave socket cavity within the socket cradle. The assembly may further include a flexible sealing boot having a first end adapted for disposition in sealing relation about the distal collar segment and a second end adapted to sealingly surround a portion of the ball stud outboard from the ball structure. 
         [0007]    Other features and advantages of the disclosure will become apparent to those of skill in the art upon review of the following detailed description, claims and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a schematic perspective view illustrating an exemplary embodiment of a linking arm assembly consistent with the present disclosure; 
           [0009]      FIG. 2  is a schematic exploded view illustrating the components of the exemplary linking arm assembly of  FIG. 1  consistent with the present disclosure; 
           [0010]      FIG. 3  is a schematic view illustrating one embodiment of a terminal end of an exemplary connecting rod adapted for matable engagement with an associated socket head in an exemplary linking arm assembly consistent with the present disclosure; 
           [0011]      FIG. 4  is a schematic, cross-sectional view illustrating the exemplary connecting rod terminal end of  FIG. 3  matedly engaging an associated segment of a socket head in an exemplary linking arm assembly consistent with the present disclosure; 
           [0012]      FIG. 5  is a schematic view illustrating the final inserted engagement between the exemplary connecting rod terminal end of  FIG. 3  and an associated segment of a socket head in an exemplary linking arm assembly consistent with the present disclosure; 
           [0013]      FIG. 6  is a schematic perspective view illustrating an exemplary socket head incorporating a socket cavity with optional spring biasing flap membranes and flexible ribs in a hub and spoke orientation adapted for continuous centering and biasing contact against a cooperating ball structure following installation of a ball stud into the socket cavity in a linking arm assembly consistent with the present disclosure; 
           [0014]      FIG. 7  is a schematic view illustrating a perimeter portion of the exemplary socket head of  FIG. 6  with the spring biasing flaps in a relaxed, unloaded condition; 
           [0015]      FIG. 8  is a view similar to  FIG. 7  illustrating the spring biasing flaps in loaded condition corresponding to insertion of a ball stud in a linking arm assembly consistent with the present disclosure; 
           [0016]      FIG. 9  is a schematic exploded view similar to  FIG. 2  illustrating the components of another exemplary linking arm assembly consistent with the present disclosure; and 
           [0017]      FIG. 10  is a view similar to  FIG. 6 , illustrating an alternative embodiment of an exemplary socket head incorporating a socket cavity adapted to provide enhanced pull out force and with grease grooves in a hub and spoke orientation. 
       
    
    
       [0018]    Before the exemplary embodiments of the invention are explained in detail, it is to be understood that the invention is in no way limited in its application or construction to the details and the arrangements of the components set forth in the following description or illustrated in the drawings. Rather, the invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for purposes of description only and should not be regarded as limiting. The use herein of terms such as “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof 
       DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0019]    Reference will now be made to the drawings, wherein like elements are designated by like reference numerals in the various views. Referring now jointly to  FIGS. 1 and 2 , an exemplary linking arm assembly  10  consistent with the present disclosure is shown. As illustrated, the exemplary linking arm assembly may include a rod  12  of elongated construction formed of plastic, metal, ceramic, or other suitable material extending between a pair of socket heads  14 . In this regard, the linking arm assembly may have the illustrated “Z” shaped arrangement, although other arrangements including, without limitation, a “C” shaped, “L” shaped or “I” shaped construction may likewise be utilized depending on the final environment of use. Moreover, while socket heads  14  are illustrated at both ends of the rod  12 , a single socket head at one end may likewise be used if desired. The socket heads  14  may be of substantially unitary molded construction having a degree of elastomeric character to facilitate insertion and retention of the rod  12  and a ball stud  40  in a manner as will be described further hereinafter. By way of example only, and not limitation, the socket heads  14  may be molded from a resilient, flexible polymer such as thermoplastic polyurethane (TPU) or the like. However, other resilient materials such as natural and synthetic rubber may likewise be used if desired. 
         [0020]    As best seen through joint reference to  FIGS. 2-4 , the rod  12  may have a generally polygonal cross-sectional geometry so as to present a number of substantially planar faces about the perimeter. In this regard, while the rod  12  is illustrated as having a substantially square cross section so as to present four substantially equivalent planar faces extending between corners along the length dimension of the rod, it is likewise contemplated that virtually any other perimeter geometry may be used as desired. In practice, the rod  12  may be molded as a unitary structure from relatively rigid structural polymeric materials such as acetal resin, nylon and the like. Of course, other polymeric materials and non-polymeric materials such as metal and the like also may be used if desired. 
         [0021]    As shown, in the exemplary construction each end of the rod  12  includes opposing outboard terminal ends  15  with a set of spaced-apart surface ribs  16  disposed in adjacent, inboard relation to each of the terminal ends  15 . As best seen in  FIG. 3 , the surface ribs  16  project radially away from the surface of the rod  12  in a direction substantially perpendicular to a longitudinal axis extending along the length dimension of the rod  12  so as to define a localized enhanced diameter relative to the terminal ends  15  and the center portion of the rod inboard from the set of surface ribs  16 . In this regard each set of surface ribs  16  may include two or more ribs positioned at different elevations along the length of the rod  12 , such that a depression  18  is formed between the adjacent surface ribs  16 . As best seen in  FIGS. 3 and 4 , in this arrangement the surface ribs  16  define a substantially sine-wave profile adjacent each terminal end  15 . 
         [0022]    As shown, in accordance with one exemplary practice, the surface ribs  16  may be in the form of ring segments disposed at each planar surface of the rod  12  so as to cooperatively extend substantially about the circumference of the rod  12 . However, it is likewise contemplated that one or more surfaces on the rod  12  may be free from surface ribs  16  if desired such that surface ribs  16  do not extend completely about the circumference of the rod  12 . As illustrated, the surface ribs  16  may define raised arcs extending between adjacent corners of the rod  12  with the apex of the arcs disposed substantially at the center of each planar face on the rod  12 . However, other radially projecting constructions may likewise be used. 
         [0023]    As best seen in  FIGS. 3 and 4 , the surface ribs  16  may have a substantially rounded cross-sectional profile so as to define substantially smooth rounded noses projecting away from the body of the rod  12  with curved upper and lower surfaces converging towards the outer edges of the ribs  16 . In this regard, it is contemplated that the surface ribs  16  may be substantially similar to one another in size and shape. However, surface ribs  16  with different sizes and/or shapes may likewise be used if desired. Moreover, while the illustrated exemplary construction incorporates pairs of spaced-apart surface ribs  16  at each end of the rod  12 , it is likewise contemplated that a single surface rib may be used or that cooperating surface ribs  16  may be arranged in sets of three or more ribs in spaced-apart relation to one another along the length of the rod  12  if desired. 
         [0024]    In the illustrated exemplary embodiment, each of the socket heads  14  may have a generally “L” shaped construction incorporating a proximal body segment  20  of open-ended tubular construction extending away from a generally bowl-shaped socket cradle  22 . In the illustrated construction, the socket heads  14  may also include a distal collar segment  24  of substantially hollow ring construction oriented in substantially aligned relation to the socket cradle  22 . In practice, the socket heads  14  may be molded as unitary structures from thermoplastic materials such as TPU (thermoplastic polyurethane), TPE (thermoplastic elastomer), or other similar material which is adapted to deform and recover resiliently in response to installation forces. 
         [0025]    As illustrated, the proximal body segment  20  of each of the socket heads  14  may include an access opening  26  leading into a rod receiving channel adapted to receive a complimentary terminal end  15  of the rod  12  in press-fit relation at the interior of the proximal body segment. In this regard, the access opening  26  may have a perimeter geometry substantially matching the circumferential geometry and size of the rod  12  so as to provide a snug fit. However, other shapes may likewise be used if desired. As best seen in  FIG. 4 , the interior of the proximal body segment defining the rod receiving channel may be molded to substantially matedly conform to the exterior of the portion of the rod  12  which is retained therein. In accordance with one exemplary practice, the interior of the proximal body segment  20  may be molded with a mating profile of spaced-apart scalloped indentures positioned to substantially overlay the surface ribs  16  on the rod  12  to provide substantially zero tolerance or slight interference between the rod  12  and the interior of the proximal body segment  20  when the rod  12  is in the final inserted condition. In this regard, a slight interference condition wherein the inner diameter of the receiving channel in the proximal body segment  20  is slightly smaller than the outer diameter defined by the surface ribs  16  may be desirable such that in the final inserted condition the proximal body segment  20  is in tension around the rod  12  and free play between the rod  12  and the socket head  14  is substantially eliminated. 
         [0026]    As will be appreciated, the combination of the sine-wave profile defined by the surface ribs  16  and the mating profile at the interior of the proximal body segment  20  may aid in providing a secure tension-fit connection between the rod  12  and the socket head  14  by providing interference against undesired withdrawal of the rod  12 . Moreover, such an arrangement may facilitate a snap-in assembly procedure whereby a person can feel the rod  12  snap into place in the final desired orientation within the proximal body segment  20  during the assembly process. In this regard, as the rod  12  is inserted into the proximal body segment  20 , the outermost surface rib will first encounter a radially inwardly projecting detent  28  defining a cusp between scalloped indentures at the interior of the proximal body segment  20  and the proximal body segment  20  will deform resiliently to permit passage of the relatively rigid surface rib. As the rod  12  is then pushed further inwardly, the detent  28  may snap back into place in substantial alignment with the depression  18  between the surface ribs  16  ( FIG. 4 ). This snap action permits a person to feel that full and proper insertion has occurred. The resulting connection will be secure, but may be reversed upon the intentional application of adequate axial separation force. As best seen in  FIG. 5 , in the final inserted condition, the resilient character of the proximal body segment  20  aids in causing the access opening  26  to seal tightly around the rod  12  at a position inboard from the surface ribs  16 . This seal aids in preventing the introduction of dirt or other contaminants into the socket head structure. 
         [0027]    Referring now to  FIGS. 1 ,  2  and  6 , in the illustrated exemplary construction, the socket heads  14  are adapted to receive and retain a ball stud  40  incorporating a ball structure  42  at a proximal end and an engagement structure  44  such as a threaded connection or the like at a distal end. In this regard, while the ball stud  40  is illustrated as having an engagement structure  44  in the form of a male thread, it is likewise contemplated that the engagement structure  44  may be any other male or female connection element as may be desired. 
         [0028]    As shown, in the exemplary construction, the socket cradle  22  houses an interior socket cavity  50  ( FIG. 6 ) adapted to receive and retain the ball structure  42  of a cooperating ball stud  40 . In this arrangement, the ball structure  42  may be matedly inserted through a stud insertion passageway  53  within the distal collar segment  24 . As shown, the stud insertion passageway  53  is in substantially aligned relation with the back of the socket cavity  50 . An elastomeric sealing boot  54  of rubber, plastic, or the like may fit in sealing relation circumferentially about the distal collar segment  24  such that the sealing boot  54  and the stud insertion passageway  53  within the distal collar segment  24  are in substantially coaxial relation. In the illustrated exemplary construction, the sealing boot  54  includes a substantially annular outer face  56  defining a stud acceptance opening  58  aligned with the stud insertion passageway  53  and adapted to receive the proximal end of the ball stud  40 . In this regard, the stud acceptance opening  58  may expand resiliently during insertion of the ball structure  42  and then rebound to sealingly surround a reduced diameter neck  46  inboard from the ball structure  42 . As shown, a raised hollow nipple  60  of flexible character may surround the stud acceptance opening  58  to aid in forming a seal about the neck  46  following insertion of the ball stud  40 . As will be appreciated, the sealing boot  54  may act to contain any lubricant within the socket cavity  50  while also blocking debris from entering the joint. 
         [0029]    Referring now jointly to  FIGS. 6-8 , in one exemplary construction, the socket cavity  50  may optionally include a pair of molded-in flexible flaps  62  of substantially wedge-shaped cross-section arranged in a generally “V” orientation relative to one another at the base of the socket cavity  50  such that free edges of the flaps  62  diverge from one another. The flaps  62  are oriented with their length dimension substantially parallel to the stud insertion passageway  53  defining the insertion path of the ball structure  42 . In practice, the flaps  62  are adapted to flex resiliently from their normal unstressed position ( FIG. 7 ) towards the adjacent inner wall  63  of the socket cavity  50  ( FIG. 8 ) when the ball structure  42  is within the socket cavity  50 . In this flexed condition, the flaps  62  will define leaf spring elements which bias continuously against the surface of the ball structure  42  during rotation of the ball structure  42  within the socket cavity. As will be understood, such a continuous biasing relation may permit the flaps to maintain contact with the ball structure  42  as surfaces wear over time. Of course, it is also contemplated that the flaps  62  may be eliminated if desired. 
         [0030]    As best seen in  FIG. 6 , the socket cavity  50  may also include an arrangement of flexible raised interior ribs  66  which are molded into the socket cavity and are adapted to press against the ball structure  42  during use. As shown, the interior ribs  66  may follow the contour of the bowl-shaped socket cavity  50  so as to extend both radially and axially within the interior of the socket cavity. As illustrated, in the exemplary orientation, one of the ribs  66  may extend between the flaps  62  at the base of the socket cavity if desired. In the illustrated exemplary construction, a substantially flat, flexible raised hub  67  may be molded into the back of the socket cavity  50  in substantial alignment with the stud insertion passageway  53  such that the interior ribs  66  and the raised hub  67  form a hub and spoke orientation. Pockets  68  defining depressions between the interior ribs  66  may act to retain lubricant and to prevent debris from contacting the ball surface. Since the socket head  14  may be molded as a unitary structure, all interior components may be formed from a common resilient polymeric material. 
         [0031]    As will be appreciated, the flexible socket cradle  22  and flexible interior ribs  66  may facilitate ease of ball insertion during assembly. Moreover, the flexible interior ribs  66  of resilient character may provide a level of precompression to establish torque at levels to achieve desired performance and durability. 
         [0032]    As will be understood, a linking arm assembly in accordance with the present disclosure may be readily adapted to a wide variety of environments by changing the length and/or geometry of the rod. By way of example only, and not limitation,  FIG. 9  illustrates an alternative embodiment consistent with the present disclosure wherein elements described previously are designated by corresponding reference numerals increased by  100 . As shown, in this embodiment, the rod  112  is substantially round in cross section and the surface ribs  116  extend in annular relation around the full perimeter of the rod  112 . The access openings  126  in the socket heads  114  are likewise circular to receive the rod  112  in sealed relation. In all other respects, the embodiment of  FIG. 9  acts in accordance with the description as provided previously. 
         [0033]    In some environments of use it may be desirable to provide a substantially high ball stud pull out force. For such applications the socket cavity may be constructed to enhance the surface area contacting the ball structure while nonetheless permitting relative rotation as may be desired. Referring now to  FIG. 10 , one embodiment consistent with the present disclosure and providing enhanced pull out force is illustrated, wherein elements described previously are designated by corresponding reference numerals within a 200 series. 
         [0034]    In the illustrated exemplary socket head  214  of  FIG. 10  which is adapted to provide high ball stud pull out force, both the flaps and the interior ribs have been eliminated such that the socket cavity  250  defines a substantially smooth, concave surface adapted to receive a cooperating ball structure (not shown). In this construction, a pattern of relatively narrow grease grooves  266  may be arranged in a hub and spoke configuration relative to a shallow grease well  267  at the rear of the cavity. In this regard, the grease grooves  266  may be arranged in substantially the same pattern as the raised ribs described in relation to the earlier described embodiments. 
         [0035]    In the exemplary construction illustrated in  FIG. 10 , the socket cavity  250  may have a diameter which substantially matches, or is slightly less than the cooperating ball structure (not shown) so as to promote a close fit relationship. The socket cavity depth extends about an arc which is greater than 180 degrees such that the socket cradle  222  extends in wrap-around relation past the midpoint of the ball structure upon insertion of the ball structure. As will be appreciated, in this construction the high surface area interface between the interior of the socket cavity  250  and the surface of the ball structure will substantially increase the force required to pull the ball structure out of the flexible socket cradle  222 . The substantially wedge-shaped surface elements  268  disposed between the grease grooves  266  may act as slightly compressible spring elements which continuously bias against the surface of the cooperating ball structure so as to promote centering while maintaining contact and preventing looseness during use. At the same time, lubricant may be transmitted between the socket cavity  250  and the ball structure through the grease grooves  266  thereby facilitating relative rotation during use. 
         [0036]    While various spatial and directional terms, such as upper, horizontal, vertical, front and the like may used to describe embodiments of the present invention, it is understood that such terms are merely used with respect to the orientations shown in the drawings. The orientations may be inverted, rotated, or otherwise changed, such that an upper portion is a lower portion, and vice versa, horizontal becomes vertical, and the like. 
         [0037]    Of course, variations and modifications of the foregoing are within the scope of the present disclosure. It is to be understood that the disclosure herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present disclosure. The embodiments described herein will enable others skilled in the art to utilize the contents of the disclosure. The claims are to be construed to include alternative embodiments to the fullest extent permitted by the prior art.