Abstract:
A backlite control system is provided for an automotive vehicle having a convertible roof. In another aspect of the present invention, a backlite control link uses a living hinge to aid in controlling the travel of the backlite during expansion and retraction of the convertible roof. A further aspect of the present invention employs a backlite control link directly connected to the number four roof bow of the convertible roof assembly.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
     The present invention generally relates to convertible automotive vehicle roofs, and more particularly to a backlite control system in a convertible vehicle. 
     Soft-top convertible roofs for use in automotive vehicles have commonly consisted of a fabric top supported by at least four roof bows and a glass back window, also known as a backlite. As the convertible roof is extended or retracted, the backlite tends to partially collapse into a portion of the vehicle&#39;s rear interior space due to its weight pulling the loose fabric top. This can intrude into the rear of the passenger compartment thereby undesirably interfering with passengers, seat backs or other objects. 
     To overcome this concern, control links have occasionally been employed in convertible roof systems to control the movement of the backlite during advancement and retraction of the roof. An example of such a control link is disclosed in U.S. Pat. No. 5,788,316 entitled, “Folding Top for a Convertible” which issued to Rothe on Aug. 4, 1998. A device such as this, however, includes a complicated combination of articulating, heavy, metal links which attach to the side of the backlite. These links are not preferable because they are inflexible, cumbersome and may not provide for the desired accuracy of control of the backlite during extension and retraction of the roof assembly. 
     Another conventional method of controlling the position of the backlite during roof operation is to use ramps attached to the vehicle&#39;s rear seatbacks. As the roof is extended or retracted, the backlite is guided along these ramps into its desired position. However this method for controlling the backlite is not desirable as the repetitive movement of the backlite along the ramps causes rubbing and wearing of the vehicle seat backs and a lack of positioning accuracy. 
     In accordance with the present invention, a backlite control system is provided for an automotive vehicle having a convertible roof. In another aspect of the present invention, a backlite control link uses a living hinge to aid in controlling the travel of the backlite during expansion and retraction of the convertible roof. A further aspect of the present invention employs a backlite control link directly connected to the number four roof bow of the convertible roof assembly. In still another aspect of the present invention, a backlite control link is polymeric. 
     The backlite control system of the present invention is advantageous over conventional devices because the present invention employs a living hinge and directly attaches the backlite to the roof bow. This is advantageous because the living hinge permits a smoother control of the backlite during operation of the roof. In addition, the control link of the present invention accurately controls the movement of the backlite so as to prevent the backlite from interfering with persons or objects located in the rear passenger area of the vehicle during movement of the roof. Another advantage of the control link of the present invention is that it is constructed of a relatively small and simple part made of polymeric material which is lighter in weight and much less complex than conventional metal linkages thereby improving vehicle fuel efficiency and piece cost. Additional advantages and features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view showing the preferred embodiment of a backlite control system of the present invention; 
     FIG. 2 is an exploded, perspective view showing the preferred embodiment of the backlite control system of the present invention; 
     FIG. 3 is an enlarged cross-sectional view, taken within circle  3  of FIG. 4, showing the preferred embodiment of the backlite control system of the present invention; 
     FIG. 4 is a fragmentary side elevational view showing the preferred embodiment of the backlite control system of the present invention, with the roof disposed in a fully extended position; 
     FIG. 5 is a fragmentary side elevational view showing the preferred embodiment of the backlite control system of the present invention, with the roof disposed in a partially retracted position; 
     FIG. 5 a  is an enlarged cross-sectional view, taken within circle  5   a  of FIG. 5, showing the preferred embodiment of the backlite control system of the present invention; and 
     FIG. 6 is a fragmentary side elevational view showing the preferred embodiment of the backlite control system of the present invention, with the roof disposed in a fully retracted position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1 through 3 show the preferred embodiment of a backlite control system employed in a convertible roof assembly  10  of an automotive vehicle  12  of the present invention. Convertible roof assembly  10  includes a linkage assembly or top stack mechanism covered by a pliable fabric top covering  14 . More specifically, the linkage assembly includes a number one roof bow  16 , a number two roof bow  18 , a number three roof bow  20 , a number four roof bow  22  and a number five or rearmost roof bow  24 . Four bow  22  is preferably a hollow and tubular metallic member although alternate extruded, molded or stamped shapes can be employed. Convertible roof assembly  10  is movable from a raised and extended position covering the vehicle&#39;s passenger compartment, as is shown in FIGS. 1 and 4, to a fully retracted and stowed position within a boot or storage area as shown in FIG.  6 . 
     Convertible roof assembly  10  also has a back window assembly including a backlite or back window  26  and a backlite retainer  28 . Backlite  26  is attached to a rear panel of roof covering  14  by way of backlite retainer  28  preferably by insert-molded encapsulation, but alternately by sewing, stapling, adhesive bonding, sonic welding or the like. Backlite  26  is preferably constructed as a three-dimensionally curved glass pane but may alternately be a pliable and transparent, polymeric sheet. Retainer  28  is preferably insert molded onto a peripheral edge of backlite  26  and attached to covering  14 , and is made from a polyurethane polymer. Retainer  28  also acts as an elastic weather seal or gasket. 
     Referring now to FIGS. 2,  3  and  5   a , a backlite control link  30  is shown attached to top cover  14  and backlite retainer  28 . Control link  30  is preferably injection molded from an engineering grade, polymeric material. Control link  30  is comprised of a half-annular end section  32 , a central section  34 , a living hinge section  36  and an attaching section  38 . A fore-and-aft elongated slot  40  is located along the center of the half-annular end section  32 . Control link  30  is rigidly fixed to top cover  14  by inserting four bow  22  into the half-annular end section  32  and then securing the control link  30  with a rivet or screw fastener  42  through slot  40  and into an aperture  44  in the four bow. Fastener  42  is allowed to slide within slot  40  as a lost motion pin or structure. 
     In a preferred embodiment of the present invention, attaching section  38  of control link  30  has a pair of apertures  46 . Control link  30  is attached to backlite retainer  28  by inserting a mechanical fastener  48 , such as a screw or rivet, through the aperture  46  for securing attaching section  38  to backlite retainer  28 . In an alternative embodiment, attaching section  38  of control link  30  may be attached to backlite retainer  28  by way of optional adhesive bonding  50  and/or encapsulation within a PVC or polyurethane retainer  28 , using the process disclosed in the following U.S. Pat. Nos.: 6,341,810 entitled “Covering Arrangement such as a Softtop for a Motor Vehicle” which issued to Hartmann et al. on Jan. 29, 2002; U.S. Pat. No. 5,822,932 entitled “Method for Making a Vehicle Window Panel Using a Melt-Processible Gasket Material” which issued to Agrawal on Oct. 20, 1998; and 5,807,515 entitled “Method for Making Vehicle Panel Assembly” which issued to Fisher et al. on Sep. 15, 1998; all of which are incorporated by reference herein. 
     Returning to the preferred embodiment, slot  40  in combination with living hinge  36 , enables control link  30  to flexibly control and move backlite  26  during both retraction and extension of convertible roof assembly  10 . The fore-and-aft size of slot  40  determines the degree of rotation of backlite  26  relative to the position of four bow  22 . Specifically, the larger the slot, the greater the flexion of living hinge  36  which results in a greater degree of rotation of backlite  26 , relative to the position of four bow  22 . Conversely, the smaller the slot, the smaller the flexion of living hinge  36  which results in a smaller degree of rotation of backlite  26 , relative to the position of four bow  22 . 
     Control link  30  accurately controls the position of backlite  26 , in a very direct and essentially one-piece manner, through its travel as the convertible roof assembly  10  cycles between an extended and raised position, and a fully retracted position, as shown in FIGS. 4 through 6. FIGS. 3 and 4 show convertible roof assembly  10  in a fully extended position. As the assembly retracts, as is illustrated in FIGS. 5 and 5 a , living hinge  36  of control link  30  flexes about a generally cross-car and horizontal axis in relation to the movement of four bow  22 , guiding backlite  26  away from the rear vehicle compartment towards its final retracted position. FIG. 6 shows convertible roof assembly  10  in its fully retracted position within the storage compartment of the vehicle. As shown, control link  30  has guided the retraction of backlite  26  so that, in its fully retracted position, backlite  26  is located below a horizontal plane defined by five bow  24 . Furthermore, upon extension of convertible roof assembly  10 , control link  30  keeps backlite  26  out of the rear passenger area of the vehicle as five bow  24  cycles up. 
     While the preferred embodiment of the convertible backlite control system has been disclosed, various alterations can be made which fall within the scope of the present invention. For example, the backlite retainer can be metallic, an injection molded polymer, a synthetic rubber gasket, or PVC. Furthermore, a differing number of roof bows can be employed such that the backlite control link may attach to a three bow or a five bow. Moreover, the disclosed control link can be coupled to the rear of a hard top front roof section and a backlite attached to a soft top rear roof section. The present invention can also apply to a side window in a convertible roof although some of the present advantages may not be fully realized. Additionally, an alternate lost motion coupling configuration of the backlite control link to roof bow may be provided through use of a slot in the roof bow and fixed pin in the control link, camming and follower surfaces, concentric hub and sleeve constructions, an added multi-pivoting link and the like, although the presently disclosed simplicity may be sacrificed. While various materials and angles have been disclosed, others may of course be used. The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.