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CLAIM FOR PRIORITY 
       [0001]    This application claims priority from U.S. Provisional Application Ser. No. 62/293,202 entitled “Shower Door System With Gravity Hinge,” filed on Feb. 9, 2016, the contents of which are incorporated herein, in their entirety. 
     
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0002]    The present invention relates generally to the art of shower door enclosures and more particularly to a shower door featuring a gravity hinge to provide the door with a self-closing action. 
       Background of the Invention 
       [0003]    Bathroom design has achieved a significant level of importance in the overall appearance of a home. Architects and homeowners today are insisting that every detail of bathroom appearance be precise and decorative in nature. Unfortunately, when it comes to installing shower doors, available shower door binges are generally not in conformance with the otherwise highly decorative theme of the modern residential bathroom. Prior art shower door hinges are typically bulky, exposed mechanical devices that are decidedly not decorative its nature. 
         [0004]    Most shower doors presently available are constructed of metal and glass and are of the swinging door type. Such doors usually are affixed to the shower enclosure at the pivoted edge of the door using piano style hinges which often extend the full height of the door. Prior art hinges typically connect the metal frame of the door to the enclosure jamb and are bolted to the jamb in several places as is required to adequately support the weight of the door. In a typical installation, the free edge of the door swings against a vertical metal strike plate which is bolted to the door jamb on that side of the enclosure. The strike plate serve as a positive stop to the door&#39;s travel. A spring biased latch is also often used in conjunction with the strike plate to keep the door in the closed position. 
         [0005]    Traditional methods of affixing a shower door to an enclosure as described above have proven to be undesirable in modern high-end shower enclosures. Modern high-end shower enclosures typically feature a glass door set into a glass wall. In this style of installation, it is desirable to polish the vertical edges of the glass door and leave the vertical edges unframed to create the appearance of an unbroken glass wall. 
         [0006]    Piano style hinges and most other prior art shower door hinges are poorly suited to the glass wall style of shower enclosure because the glass door lacks vertical frame rails and the glass wall lacks a jamb structure. Thus, no suitable structure is present within which to install the hinges on the pivoted edge of the door and the strike plate on the free edge of the door. While it may be possible to install the hinges and strike plate directly to the glass door and associated glass wall structure, any such installation would be unsightly and unacceptable to both architects and consumers. 
         [0007]    What is needed therefore, is an alternative to the traditional piano style door hinge specifically designed to work with glass doors installed in glass wall shower enclosures. Any such hinge system should be sufficiently compact so that it may be hidden within relatively low profile bottom and top rails attached to the glass shower door to provide for an unbroken glass wall appearance. Ideally, the hinges would not attach to any part of the vertical surface of the glass door. It would further be desirable that the hinges incorporate a self-closing feature eliminate the need for a strike plate and latch on the free end of the door. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention solves the problems of the prior art by providing a glass shower door, a sloping sill, a sill angle adapter, upper and lower horizontal door frame rails, and a shower door hinge assembly where the hinges include a self-closing feature and attach only to horizontal edge surfaces of the glass door, i.e. the hinges do not attach to any vertical surface of the door. The hinges of the present invention comprise a lower hinge with self-closing provisions which is used in conjunction with a pivot style upper hinge. The lower and upper hinges are sufficiently compact such that the upper hinge may be hidden within the upper horizontal rail of the door and the header of the shower enclosure and the lower hinge may be hidden within the lower horizontal rail of the door and the sill of the shower enclosure. 
         [0009]    The gravity style lower hinge of the invention includes lower or fixed portion and an upper or rotating portion where the fixed portion mounts to the sill of the shower enclosure and the rotating portion mounts to a lower horizontal rail attached to the lower horizontal edge of the glass door. The fixed portion of the lower hinge includes a cylindrical receptacle for receipt of a pintle or pin fixed to the shower door. Arranged radially about an opening of the receptacle and spaced angularly from a longitudinal axis of the fixed half of the lower hinge are a pair of mutually opposed raised surfaces and a pair of mutually opposed grooves or low surfaces. Joining the each raised surface and each groove or low surface is an interconnecting ramp. The radial centers of the raised surfaces, grooves and interconnecting ramps are measured angularly from a longitudinal axis of the fixed portion of the lower hinge. The angular position of these futures are as follows: The raised surfaces are located at 0° and 180°. The grooves are located at 90° and 270°. The ramps are located at 45°, 135°, 225° and 315°. 
         [0010]    The rotating portion of the lower hinge contains essentially the same features as the fixed portion, except that the features are clocked 90 degrees from those of the fixed portion. In particular, the rotating portion of the lower hinge includes raised surfaces, grooves, and ramps which interconnect the raised surfaces and the grooves. The angular position of these features on the rotating portion of the lower hinge, with respect to a longitudinal axis of the rotating portion of the lower hinge, are as follows: The raised surfaces are located at 90° and 270°. The grooves are located at 0° and 180°. The camming ramps are located at 45°, 135°, 225° and 315°. 
         [0011]    The fixed and rotating portions of the lower hinge are configured to be engaged when installed. At all times, the fixed portion of the lower hinge remains in a fixed position attached to the sill, whereas the rotating portion of the lower hinge is attached to the shower door and rotates as the door is opened or closed. The grooves define the self-centering or closed position of the door. With the door is at rest in the closed position, the raised surfaces of the rotating portion of the lower hinge rest in mating grooves in the fixed portion of the lower hinge. Likewise, the raised surfaces of the fixed portion of the lower hinge will rest in mating grooves of the rotating portion of the hinge. When the door is pushed outwardly, the raised surfaces of the rotating portion of the lower hinge ride upwardly along the ramps of the fixed portion of the hinge. When the raised surfaces of the rotating portion are positioned on the ramps of the fixed portion, the weight of the door will bias the raised surfaces towards the self-centered or closed position in the grooves. Thus, if the door is released, the door will close of its own accord. 
         [0012]    Continued pushing of the shower door outwardly, will cause the raised surfaces of the rotating portion of the hinge to continue to ride up the ramps on the fixed portion of the hinge until the raised surfaces of the rotating portion of the hinge rest upon the raised surfaces of the fixed portion of the hinge. Once the raised surfaces of the rotating portion of the hinge rest upon the raised surfaces of the fixed portion of the hinge, the door will then open freely, i.e. the bias due to the weight of the door is then removed and the door will not close of its own accord. If the open door is then pushed inwardly, once the raised surfaces of the rotating portion slide off those of the fixed portion and begin descending the ramps of the fixed portion, the door will again be biased to the self-centered or closed position. The arc width of the ramps and the raised surfaces controls the range of motion for which the door will be biased to a closed position or allowed to travel freely. 
         [0013]    In at least the region spanned by the shower door, the sill of the shower door and hinge assembly of the present invention is configured to slope downwardly towards the drain (inwardly) of the shower enclosure. The downward angle of the sill assists in preventing water from escaping the shower enclosure via the opening for the shower door. To allow for installation of the lower door hinge and the lower horizontal frame rail on the shower door, a sill adapter is provided to create a level surface. On the portion of the lower horizontal frame rail adjacent the lower door hinge, a sweep seal is provided to seal the gap between the lower frame rail of the door and the sill or sill angle adapter. The above and other advantages of the shower door system of the present invention will be described in more detail below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a schematic representation of a shower door and hinge assembly of the present invention installed in a shower enclosure. 
           [0015]      FIG. 2  is a cross-sectional view taken along the line  2 - 2  of  FIG. 1 , showing details of the lower hinge of the shower door and hinge assembly of the present invention. 
           [0016]      FIG. 3  is a cross-sectional view taken along the line  3 - 3  of  FIG. 1 , showing details of the lower horizontal rail and sweep seal assembly of the shower door and hinge assembly of the present invention. 
           [0017]      FIG. 4  is a perspective view of a fixed portion of the lower hinge of the shower door and hinge assembly of the present invention. 
           [0018]      FIG. 5  is a perspective view of a rotating portion of the lower hinge of the shower door and hinge assembly of the present invention. 
           [0019]      FIG. 6  is a top view of the fixed portion of the lower hinge of the shower door and hinge assembly of the present invention. 
           [0020]      FIG. 7  is a side view of the fixed portion of the lower hinge of the shower door and hinge assembly of the present invention. 
           [0021]      FIG. 8  is an end view of the fixed portion of the lower hinge of the shower door and hinge assembly of the present invention. 
           [0022]      FIG. 9  is a top view of the rotating portion of the lower hinge of the shower door and hinge assembly of the present invention. 
           [0023]      FIG. 10  is a side view of the rotating portion of the lower hinge of the shower door and hinge assembly of the present invention. 
           [0024]      FIG. 11  is an end view of the rotating portion of the lower hinge of the shower door and hinge assembly of the present invention. 
           [0025]      FIG. 12  is a top view of a sill angle adapter of the shower door and hinge assembly of the present invention. 
           [0026]      FIG. 13  is an end view of a sill angle adapter of the shower door and hinge assembly of the present invention. 
           [0027]      FIG. 14  is a schematic view of the upper hinge assembly of the shower door and hinge assembly of the present invention. 
           [0028]      FIG. 15  is a side view of alternative embodiment of a lower hinge suitable for use with heavy shower doors. 
           [0029]      FIG. 16  is a side view of an alternative embodiment of a lower hinge suitable for use with heavy shower doors. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0030]    The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. The invention may, however, may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. 
         [0031]    With reference to  FIGS. 1 through 5 , the shower door and hinge assembly of the present invention  10  typically comprises a glass shower door  12  disposed adjacent to glass walls  14  of a shower enclosure  15 . The shower door and hinge assembly  10  further includes a sloping sill  16 , a sill angle adapter  18 , upper and lower horizontal door frame rails  20  and  22 , an upper shower door hinge assembly  26  (see  FIG. 14 ) which is a pivot style hinge and a lower shower door hinge assembly  24  (see  FIGS. 2-11 ), referred to as a gravity hinge. 
         [0032]    With reference to  FIGS. 2-11 , the gravity style lower hinge assembly  24  includes a fixed hinge portion  28  and a rotating hinge portion  30  where the fixed hinge portion  28  mounts to the sill  16  of the shower enclosure via the sill angle adapter  18  and the rotating hinge portion  30  mounts to the lower horizontal rail  22  attached to a lower horizontal edge of the glass door  12 . The fixed portion  28  of the lower hinge  24  includes a cylindrical receptacle  32  for receipt of a pivot pin  34  extending from the glass door  12 . 
         [0033]    Arranged radially about an opening  36  of the receptacle  32  of the fixed portion  28  of the lower hinge  24  and spaced angularly from a longitudinal axis  38  of the fixed portion  28  are two pairs of mutually opposed inclined surfaces referred to as ramps or camming ramps  40 , a pair of raised surfaces  42  and two grooves  44 . The radial centers of the ramps  40 , raised surfaces  42  and grooves  44 , measured angularly from a longitudinal axis  38  of the fixed portion  28  of the lower hinge  24 , are as follows: The raised surfaces  42  are located at 0° and 180°. The grooves  44  are located at 90° and 270°. The two pairs of mutually opposed camming ramps  40  are located at 45°, 135°, 225° and 315°. The arc width  41  of the camming ramps  40  controls the range of motion through which the shower door  12  will be biased to a closed position, while the arc width  43  of the raised surfaces  42  controls the range of motion for which the shower door  12  will be able to travel freely. 
         [0034]    The fixed portion  28  of the lower hinge  24  also features a water management dam  46 , which assists in preventing water from escaping the shower enclosure. Also included in the fixed portion  28  are a pair of aced apart alignment holes  48  which are configured as elongated slots. The alignment holes  48  allow for the fixed portion  28  to be attached to the sill  16  of the shower enclosure mechanical fasteners typically screws. 
         [0035]    With reference to  FIGS. 2 and 12-13 , disposed between the fixed portion  28  of the lower hinge  24  and the sill  16  is the sill angle adapter  18 . The sill angle adapter  18  includes a through-hole  66  for receipt of the pivot pin  34 , as well as mounting slots  68  which allow the sill adapter  18  to be attached to the sill  16 , typically via mechanical fasteners such as screws. 
         [0036]    With reference to  FIGS. 2, 5 and 9-11 , the rotating portion  30  of the lower hinge  24  includes a generally rectangular section  50  having rounded corners and a generally cylindrical upper section  52  formed integrally with the lower section  50 . The generally cylindrical upper section  52  includes mutually opposed raised surfaces  55 , low surfaces or grooves  54 ; and ramps or camming ramps  57 . The arc width  59  of the camming ramps  57  and the arc width  61  of the raised surfaces  55 , in conjunction with those of the fixed portion  28  of the lower hinge  24 , controls the range of motion through which the shower door  12  will be biased to a closed position or will be able to travel freely in an open position. 
         [0037]    The rotating portion  30  of the lower hinge  24  also includes a cylindrical opening  56  through which the pivot pin  34  (see  FIG. 2 ) passes. Also included are attachment holes  58 , which allow the rotating portion  30  to attach to the lower horizontal rail  20  (shown in  FIG. 1 ) of the glass door  12 . 
         [0038]    With reference to  FIGS. 1-2, and 4-8 , the lower hinge  24  is configured such that the pivot pin  34  is rigidly attached to the lower horizontal rail  20  which itself is affixed to the glass door  12 . The rotating portion  30  of the lower hinge  24  is attached to the lower horizontal rail  20  via mechanical fasteners (typically screws) (not shown) and is positioned such that the pivot pin  34  protrudes from the cylindrical opening  56  of the rotating portion  30 . Likewise, the fixed portion  28  of the lower hinge  24  is attached to the sill  16  via the sill adapter  18  by means of mechanical fasteners, also, typically screws (not shown). The shower door  12  is installed in the shower enclosure by mating the fixed and rotating portions  28  and  30 . The fixed and rotating portions  28  and  30  are mated by positioning the pivot pin  34 , which protrudes from the cylindrical opening  56  of the rotating portion  30  of the lower hinge  24 , into the cylindrical receptacle  32  of the fixed portion  28 . 
         [0039]    With reference to  FIGS. 1 and 14 , during installation of the shower door  12  into the shower enclosure  15 , the components of the upper hinge  26  between the door and the shower enclosure would also be installed. The upper hinge  26  is shown schematically in  FIG. 14 . The upper hinge  26  comprises an upper hinge block or upper portion  86 , a pivot pin  88  and a lower hinge block or lower portion  90 . The lower hinge block  90  would typically be mounted concealed in the upper horizontal rail  20 . The upper hinge block  86  would typically be mounted in a header of the shower enclosure  15 . 
         [0040]    With reference to  FIGS. 1-11 , the fixed portion  28  and rotating portion  30  of the lower hinge  24  are configured to be engaged when installed. At all times, the fixed portion  28  of the lower hinge  24  remains in a fixed position, whereas the rotating portion  30  of the lower hinge  24  rotates as the shower door  12  is opened or closed. The grooves  44  in the fixed portion  28  and the grooves  54  in the rotating portion  30 , define the self-centered or closed position of the door  12  when the grooves ( 44 ,  54 ) are engaged with the raised portions  42  of the fixed portion  28  and the raised portions  55  of the rotating portion  30 . 
         [0041]    In other words, when the shower door  12  is in the closed position, the grooves  54  of the rotating portion  30  of the lower hinge  24  located at 0° and 180° will be engaged with the raised surfaces  42  of the fixed portion  28  of the lower hinge  24  which are also located at 0° and 180°. Similarly, the raised surfaces  55  of the rotating portion  30  of the lower hinge  24  located at 90° and 270° are engaged with the grooves  44  of the fixed portion  28  of the lower hinge  24  also located at 90° and 270°. 
         [0042]    With reference to  FIGS. 1-11 , when the shower door  12  is installed in the shower enclosure  15 , the weight of the door  12  is transmitted via the raised surfaces  55  of the rotating portion  30  of the lower  24  to either the ramps  40 , raised surfaces  42  or grooves  44  of the fixed portion  28  of the lower hinge  24 , depending upon the position of the door  12 . The upper portion  30  and lower portion  28  of the lower hinge  24 , when engaged and bearing the weight of the door act as follows. 
         [0043]    When the raised portions  55  of the rotating portion  30  of the lower hinge  24  are at rest in the grooves  44  of the fixed portion  28 , the shower door  12  is in the closed or self-centered position. When the shower door  12  is pushed outwardly, the raised surfaces  55  of the rotating portion  30  of lower hinge  24  ride upwardly along the camming ramps  40  of the fixed portion  28  of the lower hinge  24 . When the raised surfaces  55  of the rotating portion  30  are positioned on the camming ramps  40  of the fixed portion  28 , the weight of the door  12  biases the raised surfaces  55  towards the grooves  44 . Thus, if the door  12  is released when the raised surfaces  55  are riding upon the camming ramps  40 , the door  12  will close of its own accord. 
         [0044]    Continued pushing of the door  12  outwardly, will cause the raised surfaces  55  of the rotating portion  30  of the lower hinge  24  to continue to ride up the camming ramps  40  of the fixed portion  28  until they reach the raised surfaces  42  of the fixed portion  28 . Once the raised surfaces  55  of the rotating portion  30  of the lower hinge  24  are on the raised surfaces  42  of the fixed portion  28  of the lower hinge  24 , the door  12  will then open freely, i.e. the bias due to the weight of the door is then removed and the door will not close of its own accord. 
         [0045]    If the open door is then pushed close, once the raised surfaces  55  of the rotating portion  30  traverse the raised surfaces  42  of the fixed portion  28  and begin descending the camming ramps  40  of the fixed portion  28 , the door  12  will again be biased to the self-centered or closed position and the raised surfaces  55  of the rotating portion will again come to rest in the grooves  44  of the fixed portion  28 . 
         [0046]    Other features of the shower door and hinge assembly of the present invention  10 , include the sill  16  which is configured to slope downwardly towards the drain of the shower enclosure. The downward angle of the sill  16  assists in preventing water from escaping the shower enclosure via the opening for the shower door. To allow for installation of the fixed portion  28  of the lower door hinge  24  on the sill  16 , the sill adapter  18  is provided to create a level surface. 
         [0047]    The lower and upper horizontal door frame rails  20  and  22  of shower door and hinge assembly  10 , are extrusions which feature a generally u-shaped channel section  60  and a sweep seal retaining section  62  for retention of a sweep seal  64 . The sweep seal  64  is provided to seal a gap between the shower door  12  and the sill  16 . 
         [0048]    The u-shaped channel sections  60  of the lower and upper horizontal frame rails  20  and  22  are configured to receive the lower and upper horizontal edges of the glass door  12 , respectively. The lower and upper horizontal frame rails  20  and  22  are bonded to lower  94  and upper  92  horizontal edges of the glass door  12  via structural adhesive placed within u-shaped channels  60 . 
         [0049]    The component parts of the shower door and binge assembly of the present invention  10  may be made from a number of materials. In the exemplary embodiment, the rotating portion  30  and fixed portion  28  of the lower hinge  24 , as well as the still angle adapter  18 , are made from a structural grade thermoplastic material having excellent dimensional stability. Suitable thermoplastic materials such as polyoxymethylene (“POM”) materials are widely available from a number of manufacturers under the trade names Delrin, Celcon, Ramtal and Duracon, among others. In the exemplary embodiment, the lower and upper horizontal frame rails  20  and  22  are made from aluminum and will typically feature stainless steel decorative cladding. These components may also be made from other extrudable metallic materials, 
         [0050]    With reference to  FIGS. 15 and 16 , a heavy door closing device  70 , which may be used with the shower door and hinge assembly of the present invention, is disclosed. The heavy door closing device  70  comprises a housing  72  end cap  74 , cover plate  76 , a spindle/cam  80 , a cam follower  78  and biasing springs  82 . The spindle/cam  80  is configured with a flat surface  84  which is engagable by the cam follower  78  to establish a closed or at rest position. When the cam follower  78  is engaged with the flat surface  84  of the spindle/cam  80 , the cam follower  78  is biased against the flat surface  84  by the biasing springs  82 . The force provided by the biasing springs  82  tends to keep a door  12  equipped with heavy closing device  70  secured in the closed position. 
         [0051]    The foregoing detailed description and appended drawings are intended as a description of the presently preferred embodiment of the invention and are not intended to represent the only forms in which the present invention may be constructed and/or utilized. Those skilled in the art will understand that modifications and alternative embodiments of the present invention which do not depart from the spirit and scope of the foregoing specification and drawings, and of the claims appended below are possible and practical. It is intended that the claims cover all such modifications and alternative embodiments.

Summary:
A shower door and hinge assembly comprising a glass shower door, a sloping sill, a sill angle adapter, upper and lower horizontal door frame rails, and upper and lower shower door hinges where the lower hinge is a gravity style hinge featuring a self-closing action, is presented. The hinges of the present invention shower door and hinge assembly arch only to horizontal edge surfaces of the glass door, i.e. the hinges do not attach to any vertical surface of the door.