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CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Utility application Ser. No. 13/659,810, filed on Oct. 24, 2012, which in turn claims priority to U.S. Provisional Application Ser. No. 61/550,808, filed Oct. 24, 2011—the contents of both applications are expressly incorporated herein by reference in their entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates generally to sliding shower doors, and, more particularly, to a headerless sliding shower door assembly. 
         [0004]    2. Background of the Invention 
         [0005]    Most conventional sliding shower door panels are comprised of fully framed translucent panels, where the frames are made from aluminum or other non-rusting metallic material. Fully framed shower door panels, though functional, are undesirable from a manufacturing, as well as an aesthetic point of view. Fully framed shower door panels are undesirable from a manufacturing viewpoint because of the material and labor costs incurred in fabricating and installing the metal frames about the translucent panels. Fully framed shower doors are also undesirable from an aesthetic point of view because unsightly oxidation typically develops on the framing members within a short period of time. 
         [0006]    The aesthetic functionality of a shower door may be improved if a method may be devised to eliminate the door frames. Likewise, elimination of the door frames would improve manufacturing efficiency by eliminating material costs and reducing manufacturing operations. Some efforts towards frameless shower doors have been attempted in the art. In particular, shower doors in which the vertical framing members are eliminated have been developed. Such doors, while a step forward in the art, nevertheless typically still retain horizontal framing members such as a lower horizontal rail member and an upper horizontal header member and therefore suffer from all of the drawbacks of fully framed shower doors, albeit to a somewhat lesser degree. Thus, there remains room for improvement in the art. 
         [0007]    It is the purpose of the present invention to provide a completely frameless sliding shower door assembly, i.e. an assembly that eliminates not only the vertical framing members of prior art doors, but also the vertical header and rail members as well. 
       SUMMARY OF THE INVENTION 
       [0008]    An exemplary embodiment of the present invention presents a fully frameless sliding shower door assembly. The assembly dispenses with the need for vertical framing members by using door panels of sufficient strength and rigidity to be fully self-supporting. The need for an upper horizontal header member is eliminated by using a unique upper guide assembly where the guide is fixed to a movable shower door panel and configured to slide about a top edge of a stationary or fixed shower door panel. The upper guide assembly, being fixed to the moveable shower door panel and sliding about a top portion of the fixed door panel, therein uses the fixed door panel to provide lateral support for the movable door panel. 
         [0009]    The need for a lower horizontal rail member is eliminated by the use of a unique roller assembly that is attachable to the movable door panel without the need for a rail member. One or more of the roller assemblies may be used in the shower door assembly as may be desired depending upon the size of the rollers, weight of the door to be supported, and aesthetic considerations. The roller assembly features an inverted generally U-shaped profile on the roller which engages with a matching, non-inverted generally U-shaped profile on the track. The mating inverted and non-inverted U-shaped profiles on the roller and track, respectively, make the roller self-centering upon the track, and therefore eliminates the need for guide channels formed into the track as is typical of prior art designs. The use of inverted and non-inverted U-shaped surfaces on the roller and track, respectively, also substantially increases the load bearing area of the roller in comparison to prior art designs which typically utilize a semicircular profile on the roller which engages a flat track. The rollers of the roller assemblies are the primary vertical load carrying members of the sliding shower door assembly, i.e. the rollers support the weight of the movable door panel. 
         [0010]    The shower door assembly of the present invention also features a first or Inboard finger guard with an L-shaped cross-section having a vertical flange and a horizontal flange, the inboard finger guard being attached to an inboard side of the roller assembly. (For the purposes of this application, the term “outboard” is defined as facing outwardly from the shower enclosure or on the outside of the movable shower door. Similarly, the term “inboard” is defined to mean facing inwardly of the shower enclosure or on the inside of the movable shower door.) The horizontal flange of the inboard finger guard faces inwardly with respect to the track and is disposed underneath an elevated horizontal flange of the track. The elevated horizontal flange of the track faces outwardly with respect to the vertical flange of the inboard finger guard. This arrangement of an inwardly facing flange on the finger guard which overlaps with an outwardly facing flange on the track fully closes out the roller on Its inboard side and therein prevents any possibility of fingers or toes from inadvertently being caught between the roller and the track on the inboard side of the roller. 
         [0011]    The shower door assembly of the present invention also features a second or outboard finger guard comprised of an upwardly raised surface on the track which inhibits finger or toe access to the roller on the outboard side of the roller. The finger guards of the present invention serve to prevent fingers and toes from getting caught between the roller and the track and represent an improvement the art because such features appear to be lacking in prior art designs. 
         [0012]    Another feature of the present invention is a track leveling feature or device which improves ease of installation. For the movable shower door to move freely, it is important that the track be level. A level track ensures even contact of the roller assembly or assemblies attached to the door and likewise ensures good alignment with abutting walls or door jambs of the shower enclosure. In the exemplary embodiment, the leveling feature comprises a threaded hole for the receipt of a set screw at one end of the track. The set screw is threaded into the hole from an upper surface of the track until the screw bears against the shower enclosure floor surface, or in the case of tub installations, the tub rail surface. Additional tightening of the set screw causes the track to rise at an angle to the floor or tub rail surface and in this manner, the track may be brought to horizontal level with respect the floor or tub rail surface, thereby substantially easing installation of the shower door assembly. 
         [0013]    The above and other features of the invention will become more apparent from the following detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a front view of a sliding shower door assembly in accordance with an exemplary embodiment of the present invention. 
           [0015]      FIG. 2  is top view of the sliding shower door assembly of  FIG. 1 . 
           [0016]      FIG. 3  is side view of the sliding shower door assembly of  FIG. 1 . 
           [0017]      FIG. 4  is an enlarged partial front view of the sliding shower door assembly of  FIG. 1 . 
           [0018]      FIG. 5  is an enlarged, partial sectional view of the roller assembly of the sliding shower door assembly of  FIG. 4 , taken along the line  5 - 5 . 
           [0019]      FIG. 6  is an enlarged, partial sectional view of the roller assembly of the sliding shower door assembly of  FIG. 4 , taken along the line  6 - 6 . 
           [0020]      FIG. 7  is an enlarged, partial sectional view of the track of the sliding shower door assembly of  FIG. 4 , taken along the line  5 - 5 . 
           [0021]      FIG. 8  is an exploded partial sectional view of the sliding shower door assembly of  FIG. 3 , showing a guide assembly for supporting a movable shower door relative a stationary shower door, wherein the guide assembly is fixed to the movable shower door and slides over an upper portion of the stationary shower door. 
           [0022]      FIG. 9  is an exploded partial sectional view of the sliding shower door assembly of  FIG. 3 , showing a guide assembly for supporting a movable shower door relative a fixed shower door, wherein the guide assembly is fixed the stationary shower door and slides over an upper portion the movable shower door. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0023]    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 hi the art. Like numbers refer to like elements throughout. 
         [0024]    With reference to  FIGS. 1 through 3 , a sliding shower door assembly  10  in accordance with an exemplary embodiment of the present invention is shown. The shower door assembly  10  comprises a movable door panel  12 , a fixed door panel  14 , an upper guide assembly  16 , one or more roller assemblies  18 , and a track  22 . The track  22  is mounted on a mounting surface  24 . The mounting surface  24  will typically be either the floor of a shower enclosure or the top surface of a tub in the case of bathtub/shower installations. The movable door panel  12  will typically also be equipped with a handle  20 . In a typical installation, the movable door panel  12  will be equipped with two roller assemblies  18  and one upper guide assembly  16 . 
         [0025]    With reference to  FIGS. 3.6 , the roller assembly  18  of the shower door assembly  10  includes a roller  26 . The roller  26  is generally cylindrical having a diameter  30  (see  FIG. 4 ) and a width  28  (see  FIG. 5 ). The diameter  30  and width  28  of the roller  26  may be scaled as needed to support the weight of the movable door panel  12  which may vary depending upon the materials chosen for the door panel&#39;s construction and the size of the door panel which may vary depending upon the requirements of any particular installation. 
         [0026]    The roller  26  features an inverted U-shaped groove or rolling surface  32  which mates with a U-shaped rolling surface  34  formed on the track  22 . The rolling surface  32  of the roller  26  and the rolling surface  34  of the track  22  are of generally the same radius of curvature to facilitate smooth rolling contact between the two rolling surfaces  32  and  34 . The U-shaped rolling surface  34  of the track  22  and the mating inverted U-shaped rolling surface  32  of the roller  26  function to keep the roller  26  centered on the track  22  during opening and closing movement of the movable door panel  12  without the need for guide channels or other guiding or roller capturing features in the track. The radius of curvature of the rolling surfaces  32  and  34  may vary but should be sufficiently deep to self-center the roller  26  on the track  22 . Experimentation has shown that a radius of curvature within the range of about ½″ to about ⅝″ to be suitable for most typical applications. The roller further includes a bore  36  for slip-fit receipt of an axle  38 . 
         [0027]    In typical installations, the roller  26  will be generally centered with respect to a thickness  40  of the movable door panel  12 , as illustrated in  FIG. 5 . Typically, the width  28  of the roller  26  will exceed the thickness  40  of the movable door panel  12 . To support and center the roller  26  within the movable door panel  12 , inboard and outboard roller clamping plates  42  and  44 , respectively are provided. The inboard and outboard roller clamping plates  42  and  44  are sized such that when the clamping plates  42  and  44  are affixed to the movable door panel  12 , the clamping plates have a combined interior width  46  (see  FIG. 5 ) slightly in excess of that of the roller  26 , to allow for free movement of the roller  26  within the inboard and outboard clamping plates  42  and  44 . The combined interior width  46  comprises the thickness  40  of the movable door panel  12  and a relieved interior width  48  of each of the inboard and outboard roller clamping plates  42  and  44 . (See  FIG. 5 .) Each of the roller clamping plates  42  and  44  also includes a blind-bore  50  which is sized to receive the axle  38  of the roller  26 . 
         [0028]    With reference to  FIGS. 4 and 6 , the roller clamping plates  42  and  44  are attached to the movable door  12  by means of fasteners  52 . For each roller assembly  18 , two fasteners  52  are used, with one fastener  52  being positioned on each side of the roller  26 , as illustrated in  FIG. 4 . Each fastener  52  passes through a through-bore  54  in the inboard roller clamping plate  42  and is affixed to a blind-bore  56  in the outboard roller clamping plate  44 . Each fastener  52  may be affixed to the blind-bore  56  of the outboard roller clamping plate by a number of means. A press fit, threaded engagement, or the use of adhesives are all suitable means for securing the fasteners  52  to the blind-bores  56  of the outboard clamping plate  44 . Generally, two fasteners  52  per roller assembly  18  are sufficient to secure the roller assembly to the movable door panel  12 . The means for attaching the roller assemblies  18  to the movable door panel  12  eliminate the need for any lower horizontal rail member attached to the movable door panel  12  in the sliding shower door assembly  10  of the present invention. 
         [0029]    The inboard and outboard roller clamping plates  42  and  44  are shown in the exemplary embodiment as having a generally semicircular shape with a beveled surface. This configuration was chosen for its pleasing aesthetic appearance. Other shapes having the utilitarian features discussed herein are also suitable. 
         [0030]    With continued reference to  FIGS. 4-6 , the roller assembly  18  may further include a first or inboard finger guard  58 . The inboard finger guard  58  features an L-shaped cross-section having a vertical flange  60  and a lower horizontal flange  62 . The inboard finger guard  58  is affixed to the inboard roller clamping plate  42  and configured such that the lower horizontal flange  62  is positioned underneath and overlaps an elevated horizontal flange  64  of the track  22 . That is the lower horizontal flange  62  of the inboard finger guard  58  faces inwardly towards the track  22  and is disposed underneath and overlaps with the elevated horizontal flange  64  of track, which faces outwardly towards the vertical flange  60  of the inboard finger guard. (See  FIGS. 5 and 6 .) Via this arrangement, the inboard finger guard  58  extends below the roller  26  and fully closes out the roller  26  on its inboard side and therein prevents any possibility of appendages such as fingers or toes from inadvertently being caught between the roller  26  and the track  22  on the inboard side of the roller assembly  18 . Through-bores  55  formed in the inboard finger guard  58  are configured to align to with the through-bores  54  of the inboard roller clamping plate and therein allow the inboard finger guard  58  to be attached to the inboard roller clamping plate  42  via the fasteners  52 . 
         [0031]    With reference to  FIGS. 5-7 , the track  22  of the sliding shower door assembly  10  of the present invention is an extrusion of complex cross-section. The track  22  features a mid-surface  66 . Extending downwardly from the mid-surface  66  is an inboard lower wall  70  and an outboard lower wall  72  which form a channel  74  therebetween. Extending from the inboard lower wall  70  is the elevated horizontal flange  64 . Extending upwardly from the mid-surface  66  are the U-shaped rolling surface  34  and a second or outboard finger guard  68  in the shape of an upwardly raised truncated V-shaped surface. The outboard finger guard  68  is sized such that a gap  76 , (see  FIG. 5 ), between the outboard finger guard  68  and the outboard roller clamping plate  44  is sufficiently small to prevent fingers and toes from extending through the gap. 
         [0032]    The inboard  58  and outboard  68  finger guards of the present invention serve to prevent fingers and toes from getting caught between the roller  26  and the track  22  and represent an improvement in the art as such features are often lacking in prior art designs. 
         [0033]    With reference to  FIG. 7 , another feature of the present invention sliding shower door assembly  10  is a track leveling feature  78  which improves the ease of installation of the track  22 . For the movable shower door panel  12  to move freely, it is important that the track  22  be level with respect to the track mounting surface  24 . The mounting surface  24  may be either the floor in the case of a standalone shower enclosure or may be a tub rail surface in the case of a bathtub/shower installation. A track  22  which is level ensures even contact of the roller assemblies  18  attached to the movable door panel  12  with the track  22  and likewise ensures good alignment with abutting walls or door jambs of the shower enclosure. Typically, two roller assemblies  18  will be used on the movable shower door panel  12 . 
         [0034]    In the exemplary embodiment, the track leveling feature  78  comprises a hole  82  which is threaded for the receipt of a set screw  80 . Typically, each track  22  will include a single leveling feature  78 , i.e. threaded hole  82  and set screw  80 , located at one end of the track. During installation, the set screw  80  is threaded into the hole  82  from the U-shaped rolling surface  34  of the track  22  until the screw bears against the track mounting surface  24 . Additional tightening of the set screw  80  causes the track  22  to rise at an angle to the mounting surface  24  and in this manner, the track  22  may be brought to horizontal level with respect the mounting surface  24 , thereby substantially easing installation of the shower door assembly  10 . 
         [0035]    With reference to  FIGS. 5 and 6 , in some installations, it may be desirable to include water proof sealing material  84  between an outboard sealing surface  86  of the track  22  and a base end or rail  88  of the fixed panel  14  of the sliding shower door assembly  10 . The sealing material  84  serves to prevent water infiltration past the base rail or end  88  of the fixed door  14 . 
         [0036]    With reference to  FIG. 8 , the upper guide assembly  16  of the sliding shower door assembly  10  of the present invention is shown in more detail. The upper guide assembly  16  is fixed to the movable shower door panel  12  and configured to slide about a top portion  108  of the stationary shower door panel  14 . Therefore, the upper guide assembly  16 , being fixed to the moveable shower door panel  12 , travels with the movable door panel as it is opened and closed. This arrangement allows the fixed door panel  14  to provide lateral support to the movable door panel  12  and therein eliminates the need for an upper horizontal header member as is typical of prior art designs. 
         [0037]    The upper guide assembly  16  includes a guide block  90 . The guide block  90  includes on its outboard side a channel  104 . The channel  104  is configured to be slidable along a horizontal length  106  (see  FIG. 1 ) of a top portion  108  of the fixed door panel  14 . The channel  104  of the guide block  90  may optionally include an inner guide liner  100  which may be made from a low friction material and which may be replaced as a wear item. On its inboard side, a vertical wall  112  and a horizontal wall  114  of the guide block  90 , in conjunction with a guide clamp plate  92 , form a channel  110 . The movable door panel  12  is clamped to the guide block  90 , within the channel  110 , via clamp screws  94 . (See  FIGS. 1 and 8 .) The heads of the clamp screws  94  bear against the clamp plate  92  whereas the threaded ends of the clamp screws thread into threaded blind-bores  98  in the guide block  90 . Alternative fasteners such as press fit pins may be substituted for the clamp screws  94 . Compression gaskets  102  may also be optionally included within the channel  110  to more uniformly distribute the clamping pressure generated by the clamp screws  94 . Optionally, bushings  96  set into the movable door  12  may be used to prevent the shank of the clamp screws  94  from bearing directly against the material of the sliding door panel  12 . 
         [0038]    With reference to  FIG. 9 , in an alternative embodiment, the orientation of the upper guide assembly  16  may be reversed from that shown in  FIG. 8 . In the embodiment shown in  FIG. 8 , described above, the upper guide assembly  16  is fixed to the movable shower door panel  12  and slides about a top portion  108  of the stationary shower door panel  14 . In this arrangement, the upper guide assembly  16  travels with the movable shower door panel  12 . 
         [0039]    In the reverse configuration shown in  FIG. 9 , the upper guide assembly  16  is fixed to the stationary shower door panel  14  and is slidably engaged with the movable shower door panel  12 , i.e. the guide block  90  is fixed to the stationary shower door panel  14  via the guide clamp plate  92  and clamp screws  94  and the channel  104  of the guide block  90  is slidably engaged with an upper portion  109  of the movable shower door panel  12 . In this configuration, the upper guide assembly  16  being fixed to the stationary shower door panel  14  remains fixed during movement of the movable shower door panel  12  which slides within the channel  104  of the guide block  90  when the movable shower door panel  12  is opened and closed. 
         [0040]    Both of the upper guide assembly  16  configurations described above will provide sufficient lateral support to the movable door panel  12 , however the configuration of  FIG. 8  where the upper guide assembly  16  is fixed to the movable shower door panel  12  and slides about an upper portion  108  of the stationary shower door panel  14  is advantageous in that the movable shower door panel  12  will remain erect in the (unlikely) event that the movable door panel  12  were to derail during use. 
         [0041]    The sliding shower door assembly  10  of the present invention is not limited to any particular choice of materials. A number of materials for each component of the assembly  10  are suitable and are known in the art. For example, the movable and fixed door panels  12  and  14  will typically be made of a relatively lightweight material that is sufficiently strong to be fully self-supporting for the purpose of eliminating any need to frame the door panels. Presently, translucent or transparent materials are preferred for shower doors in residential home installations. A variety of rigid translucent polycarbonate and acrylic materials including Lucite and Plexiglass are suitable. Opaque plastic and metallic materials are also suitable. Treated wood materials may also be suitable. 
         [0042]    The roller assembly or assemblies  18  will typically be made from metallic materials, with stainless steel and aluminum often being preferred for aesthetic reasons. Structural plastic materials however, are also suitable. The track  22  will typically be a metallic or plastic extrusion. The upper guide assembly  16  will typically be made from plastic materials. Metallic materials are also suitable. 
         [0043]    With reference to  FIGS. 1-8 , the sliding shower door  10  assembly of the present invention will typically be assembled as follows: The fixed door panel  14  will first be set into a shower enclosure as is known in the art. The track  22  will then be set into the floor of the shower enclosure using materials known in the art. The track  22  may be leveled with respect to the track mounting surface  74  using the track leveling feature  78  of the present invention. Typically, the track leveling feature  78  will be located on one end of the track  22 . Raising or lowering the set screw  80  of the track leveling feature  78  will raise or lower the track  22  at that end. In this manner the track may brought to a horizontal level condition. 
         [0044]    After the track  22  has been leveled, the roller assemblies  18  may be installed. To install each roller assembly  18  in the movable door panel  12 , first the axle  38  will be fitted into the roller  26 . The roller  26  containing the axle  38  is then fitted into an opening for receipt of the roller  26  in the movable door panel  12 . The inboard and outboard roller clamping plates  42  and  44  are then placed on inboard and outboard faces of the movable door panel  12  and positioned such that ends of the axle  38  are located within the blind-bores  50  of the roller clamping plates  42  and  44 , and the through-bores  54  of the inboard roller clamping plate  42  are aligned with the blind-bores  56  of the outboard roller clamping plate  44 . 
         [0045]    Thereafter, inboard finger guard  58  is positioned on the inboard roller clamping plate  42  and the through-bores  55  of the inboard finger guard  58  are aligned with the through-bores  54  of the inboard roller clamping plate  42 . Subsequently, the fasteners  52  are installed to thereby secure the roller clamping plates  42  and  44 , and consequently the roller assembly  18 , to the movable door panel  12 . In a typical installation, the movable door panel  12  will include two roller assemblies  18 . 
         [0046]    Upon attachment of the roller assemblies  8  to the movable door panel  12 , the movable door panel is engaged with the track  22  by sliding an outboard side of the movable door panel  12  about the track  22  such that the inverted U-shaped rolling surfaces  32  of the rollers  26  engages with the U-shaped rolling surface  34  of the track  22 . 
         [0047]    Upon engagement of the roller assemblies  18  of the movable door panel  12  to the track  22 , the upper guide assembly  16  is installed to provide lateral support to the movable door panel  12 . The upper guide assembly  18  is installed by first positioning the channel  104  of the guide block  90  about the upper portion  108  of the fixed door panel  14 . Thereafter, an upper portion  116  of the movable door panel  12  is set against the vertical wall  112  of the guide block  90 . The bushings  96  are then placed in holes  118 , (see  FIG. 8 ), for receipt of the bushings  96  formed in the upper portion  116  of the movable door panel  12 . Guide clamp plate  92  is then aligned with the holes in the bushings  96  and placed on the guide block  90  and movable door panel  12 . Thereafter, the clamp screws  94  are installed which upon installation secure the upper guide assembly  16  to the movable door panel  12 . 
         [0048]    If used, the optional inner guide liner  100  will be installed in the channel  104  of the guide block  90  prior to positioning the channel  104  of the guide block  90  about the upper portion  108  of the fixed door panel  14 . Similarly, if used, the optional compression gaskets  102  will be installed on the vertical wall  112  and the horizontal wall  114  of the guide block  90  prior to installation of the movable door panel  12  to the guide block  90 . Upon installation of the upper guide assembly  16 , the sliding shower door assembly  10  of the present invention is completed. 
         [0049]    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 fully frameless sliding shower door assembly. The assembly dispenses with the need for vertical framing members by using a panel of sufficient strength to be fully self-supporting. The need for an upper horizontal header member is eliminated by using a unique upper guide assembly wherein the guide is fixed to the movable shower door and configured to slide about a top edge of the stationary shower door. The need for a lower horizontal rail member is eliminated by the use of a unique, self-centering roller assembly that is attachable to the door panel without the need for a rail member. The roller assembly features matching inverted and non-inverted generally U-shaped profiles on the roller and track, respectively. The shower door assembly further features inboard and outboard roller finger guards, as well as a track leveling feature which improves ease of installation.