Patent Publication Number: US-7908795-B2

Title: Window carrier assembly for automotive window regulator

Description:
FIELD OF THE INVENTION 
     This invention relates to a component for automobiles and particularly to a window clamp assembly used as part of an automotive movable window regulator assembly. 
     BACKGROUND AND SUMMARY OF THE INVENTION 
     Motor vehicles have for many decades featured movable side door glass. A mechanism is required in order to move the glass between the upper closed position and the lower opened position. These mechanisms are generally known as window regulators. Window regulators can be manually operated by an operator, or can be driven by a powered actuator, most commonly an electric motor. One type of window regulator uses a pulley arrangement using a metal cable wrapped around a drum driven by an electric motor. This device uses a carrier which engages the door glass and fastens it to the window regulator assembly to control its motion as it moves vertically. 
     Window regulator mechanisms can still be categorized into a group which includes dual rail and single rail types. In a dual rail system, a pair of separated rails are provided which each include a movable window clamp which is fastened to the lower edge of the glass and move in a synchronized manner to raise and lower the glass. In a single rail type, a single rail is positioned at near the center of the window glass and includes a clamp assembly which engages the lower edge of the window. The clamp assembly moves vertically along the rail between the open and closed positions. A single rail type provides a window regulator assembly with fewer parts than a dual rail system, but poses design challenges in providing sufficient stability for the control of the glass motion since it is controlled by a single rail and window clamp assembly. 
     Designers and manufacturers of automotive components are continuously striving to reduce their cost, complexity, and weight in order to provide features and functions for motor vehicles at minimum cost. In one type of existing single rail window regulator, a window clamp assembly is provided made from a large stamping of sheet metal. The sheet metal parts are formed to span across the rail to engage the rail and further includes provisions for mounting a pair of separated clamps which fasten to the lower edge of the glass. The large sheet metal stamping requires a significant capital investment for its production because of its size, and further is a relatively heavy and expensive component to fabricate. One feature of the present invention is to provide an improved carrier assembly for a window regulator which can be formed of injection molded plastic materials with components added to them in a manner which provides a cost effective and functional clamp assembly. 
     For most window regulators of the above-mentioned cable pulley type, it is necessary to terminate the drive cable within at the carrier assembly. Various techniques for cable termination are known. It is another feature of the present invention to provide a cable termination system which provides manufacturing simplicity while meeting performance requirements for such termination. 
     Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which the present invention relates from the subsequent description of the preferred embodiment and the appended claims, taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side cut-away view of a motor vehicle door assembly showing movable door glass and portions of a window regulator assembly including features according to this invention; 
         FIG. 2  is an illustration of portions of a window regulator assembly including a carrier assembly in accordance with this invention; 
         FIG. 3  is an exploded view of the window carrier assembly of the present invention; 
         FIG. 4  is a cross-sectional view taken through the carrier assembly engaged with the guide channel; 
         FIG. 5  is a pictorial view showing the cable termination pocket with a cable end shown before being inserted into position within the pocket; 
         FIG. 6  is a view figure similar to  FIG. 5  showing one of the cable ends in an inserted position within the cable pocket; 
         FIG. 7  is a cross-sectional view of the cable pocket; 
         FIG. 7A  is a cross-sectional view taken along line  7 A- 7 A from  FIG. 7 ; 
         FIG. 7B  is a cross-sectional view taken along line  7 B- 7 B from  FIG. 7 ; 
         FIG. 7C  is a side sectional view showing the installation of a cable end into the cable pocket; 
         FIG. 8  is a side view of the window carrier assembly showing the cable ends inserted within the cable pocket with parts of the window carrier assembly cut-away to show the cable ends in elevation; 
         FIG. 9  is an exploded view of the window carrier assembly in accordance with a second embodiment of the present invention; 
         FIG. 10  is a cross-sectional view through the carrier assembly shown in  FIG. 9 ; and 
         FIGS. 11A and 11B  are cross-sectional views taken through the window clamp of the second embodiment of the present invention shown in unclamped and clamped positions respectively. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a side view of an automotive door  10  shown cut-away revealing the side movable door window  12  and a portion of window regulator assembly  14 . Door window  12  can be formed of glass or other glazing materials such as polycarbonate. The portions of window regulator assembly  14  shown in  FIG. 1  include guide channel  16  and window carrier assembly  18 . Not illustrated in  FIG. 1  are additional components of window regulator assembly  14  necessary to make it fully functional, including a drive motor and other related components. These additional components are well known and are not principal elements of this invention.  FIG. 1  illustrates the door window  12  in an intermediate position between its lowered-opened and raised-closed positions. This motion is guided by a pair of side glass run channels (not shown) along glass frame  20 . In the fully raised-closed position of window  12 , it is sealed within glass frame  20 . 
     Now with reference to  FIG. 2 , greater details of components of window regulator assembly  14  are shown. Guide channel  16  is preferably formed of sheet metal and includes a return bent flange  24 . Cable pulley  26  is used to guide a drive cable, which will be described in greater detail in the description below. Guide channel  16  acts as a rail allowing carrier assembly  18  to move along its length. 
     Carrier assembly  18  is generally comprised of a center body  28  and a pair of window clamps  30  and  32  affixed to the body. Now with reference to  FIG. 3 , additional features of carrier assembly  18  will be described. Carrier assembly body  28  is preferably formed from an injection molded polymeric material which can be cost-effectively produced. Body  28  includes cable attachment pocket  34  and further forms a pair of laterally opening clamp mounting slots  36  and  38 . Slots  36  and  38  are laterally extended longitudinal opening slots. Body  28  integrally forms a pair of tabs  40  and  42  which are attached to the remainder of body  28  along their side edges  44  and  46  such that the tabs  40  and  42  are cantilever supported. Side edges  44  and  46  enable tabs  40  and  42  to be flexed out of position from intersecting with slots  36  and  38 , and provide the function of snap engagement with window clamps  30  and  32 , as will be described in more detail below. Body  28  further forms a vertically extending channel  48  best shown by  FIG. 4  and arms  49  and  51  which wrap over the side edges of the guide channel. These features closely receive guide channel  16  interlocking body  28  with the guide channel enabling the body to slide vertically along the guide channel.  FIGS. 2 and 4  show carrier assembly  18  mounted in position on guide channel  16  to move vertically in this manner. 
     Each of clamps  30  and  32  as shown in  FIG. 3 , include bottom plates  50  and  52 , preferably formed of sheet metal, each having extending attachment ears  54  and  56 , each with apertures  58  and  60 , respectively. Clamps  30  and  32  further have additional clamp top plates  64  and  66  which cooperate with plates  50  and  52  to form a clamp to pinch together and engage the lower edge of door window  12 . Window jaws  68  and  70 , preferably formed from an elastomer, are positioned between the clamp plates to securely clamp window  12  when threaded fasteners  72  are tightened which are threaded into press nuts  74 . The respective clamp plates inter-engage one another at the lower edge of inter-fitting tabs  69  and slots  71  as shown in  FIG. 3 . 
     During assembly, attachment clamps  30  and  32  are assembled with body  28  by sliding attachment ears  54  and  56  into respective body slots  36  and  38 . During this assembly process, ears  54  and  56  are pressed into position and this motion causes tabs  40  and  42  to be deflected out of intersection with the slots  36  and  38  until the clamp ears are in their final position at which time the tabs can deflect into interlocking engagement with apertures  58  and  60 . The fully assembled positions of the clamps  30  and  32  are shown in  FIG. 4 . To enable such “snap-attachment” assembly, the tabs  40  and  42  have a chamfered leading edge which engages ears  54  and  56 , to deflect them out of position. At each of the lateral sides of carrier body  28  projection short posts  41  are formed. Posts  41  are positioned adjacent to the upper edge of clamp mounting slots  36  and  38 . When window clamps  30  and  32  are assembled with carrier body  28 , the posts  41  abut against the clamps to help stabilize the clamps, limiting their rotational displacement within slots  36  and  38 . 
     The above-described configuration for carrier assembly  18  provides a cost effective automotive component which reduces fabrication cost by minimizing the size of the stamped sheet metal components which in this case are confined to clamps  30  and  32 . Moreover, this provides a modular construction approach enabling the clamps  30  and  32  to also be used for other design systems such as dual rail window regulator assemblies. 
     Now with reference to  FIGS. 5 through 8 , details of cable pocket  34  are provided. As illustrated in  FIG. 5 , cable pocket  34  includes a center wide section  78 , narrowed intermediate sections  80  and each terminate laterally in narrow cable passages  82 . The cross-sectional width of the section decrease from center section  78  to intermediate section  80  to cable passage  82 . Each of cable ends  84  and  86  include an end button  88  attached to the end of the cable with a coil spring  90  surrounding the cable and abutting against button  88 . Cable socket center section  78  is large enough to accommodate button  88  whereas intermediate section  80  has a slightly rounded shape in cross-section and cable passage  82  is sufficiently narrow to allow cable  92  to pass but not large enough to allow coil spring  90  to be pulled through the passage.  FIG. 7A  shows the configuration of cable passage  82  which forms a narrow slot and the partially circular profile of intermediate section  80  which embraces and captures coil spring  90  and button  88 . As shown, spring  90  is captured by intermediate section  80  and is restrained to remain in that section of the cable pocket  34 . 
       FIG. 5  shows cable end  84  ready to be installed within cable pocket  34 . This is accomplished by loading the coil spring  90  and button  88  into center section  78 . Thereafter, coil spring  90  relaxes and expands into intermediate section  80  as shown in  FIG. 6 . By pulling cable  90  taut, sufficient clearance is provided for the other cable end  86  to be inserted in a similar manner.  FIG. 8  shows both of the cable ends  84  and  86  inserted. In actual use, cable  92  will be under sufficient tension such that buttons  88  are spread apart engaging the shoulder formed between center section  78  and intermediate sections  80  in their final resting position. The above-described configuration of the interaction between cable socket  76  and cable ends  84  and  86  provides a cost effective and reliable cable termination. This termination provides ease of assembly, and facilitates servicing if required. 
       FIGS. 9 ,  10 ,  11 A, and  11 B illustrate a second embodiment of a carrier assembly in accordance with the present invention designated by reference number  118 . Features of this embodiment of a carrier assembly, which are identical to those previously described, are identified by like reference numbers. Carrier assembly  118  differs from the previously described embodiment of carrier assembly  18  in that center body  128  includes a pair of projecting locating tabs  94  and  96 . In other respects, center body  128  is identical to center body  28  previously described. The function of locating tabs  94  and  96  is to further secure window clamps  30  and  32  when they are mounted to center body  128 . Specifically, the desire is to reduce the pivotal motion of the window clamps  30  and  32  when they are mounted to the center body  128  and installed within the vehicle. 
     Locating tabs  94  each have an opening V-slot  102  and  104  which have a V-shaped guide opening which ends or bottoms out in a generally round center hole as illustrated in  FIG. 9 . 
     As best shown in  FIG. 10 , window clamps  30  and  32  are assembled to center body  128 , locating tabs  94  and  96  become positioned between clamp bottom plate  50  and clamp top plate  64 . During this assembly process, V-slots  102  and  104  locate threaded fasteners  72  within their narrowed center sections. This enhances the accuracy of location and provides secure positioning of window clamps  30  and  32  when they are assembled to center body  128 . As best shown in  FIGS. 11A and 11B , tightening of threaded fastener  72  cause window jaws  68  (and  70 ) to clamp against window  12 .  FIGS. 11A and 11B  show clamp  30  which is identical to clamp  32 . 
     It is desirable that this clamping action also places a compressive force on locating tabs  94  and  96  for purposes of enhancing the security of connection between the window clamps  30  and  32  with center body  128 . While this is desired, it is also essential that clamps  30  and  32  securely clamp and structurally engage window  12 . In order to achieve these objectives, locating tabs  94  and  96  need to be mechanically engaged with the bottom and top plates  50  and  64 , respectively, through a range of clamped positions of these parts. One way of achieving this is to locate a series of flexible projections on one or both surfaces of locating tabs  94  and  96  which are illustrated as pointed projections  106  and are shown in  FIG. 11A . Thus, when threaded fastener  72  is tightened, the top and bottom plates  50  and  64  are drawn together which structurally couples with locating tabs  94  and  96  while allowing the top and bottom plates to fully clamp against and engage with window  12 . Other means of providing connection with locating tabs  94  and  96  could also be implemented. For example, a simple elastomeric pad could be placed between locating tabs  94  and  96  and surfaces of top plate  50  or bottom plate  64  (or both). Such an elastomeric pad  108  would provide compressibility over a range of compressions while not interfering of clamping of window  12 . Once threaded fasteners  72  are tightened, window clamps  30  and  32  are securely positioned with little lost motion which could otherwise lead to buzz, squeak, or rattle (BSR) problems with the associated motor vehicle. 
     While the above description constitutes the preferred embodiment of the present invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims.