Abstract:
A shower stall pan that includes an integrally molded threshold “curb” with reinforcing ribs to provide sufficient strength for direct installation into the shower structure. The reinforcing ribs are integrally molded into the shower pan structure, which includes the threshold curb. The use of reinforcing ribs under the curb obviates the requirement to use additional framing under the curb portion of the shower pan, and decreases the time, effort and skill required to install the shower pan and thereby decrease the time and effort in constructing a shower stall.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to prefabricated shower modules, and, particularly, to a pre-molded waterproof shower module bottom element that is reinforced so as to allow installation with a reduced need for additional underlying support material. 
     2. Description of the Background Art 
     The construction of a shower stall requires that a waterproof structure be placed along the floor of the shower stall. The waterproof structure is usually a one-piece, continuous surface except for a drain pipe that penetrates the structure through a waterproofjoint. This waterproof structure must cover the entire bottom of the stall floor as well as a vertical portion of the lower wall from the floor up to a suitable height from the floor so as to ensure that water standing in the stall is contained with the structure. The waterproof structure is generally referred to as a shower “pan” and various designs have been used. The conventional practice is to place a single, usually pre-fabricated, unit in the floor of the shower to form the waterproof structure. The shower floor “pan” may be constructed of any waterproof material including metal, polymeric materials or fiberglass. The pre-fabricated shower floor pans are usually constructed in a light weight, thin and relatively structurally weak manner so as to minimize the cost of the shower floor pan. These lightweight and thin units are therefore susceptible to damage during shipping. 
     A typical shower stall is usually completely enclosed by solid walls with the exception of a doorway used for ingress and egress. The doorway typically has a “curb” in its lower portion, which is a short wall (usually 4 to 10 inches high) that is used to contain water standing on the floor of the shower. The curb comprises an interior curb wall, which is a short vertical wall portion, that terminates at a horizontal portion that forms the threshold for the shower door. Since the curb is required to hold water standing on the floor of the shower, the interior curb wall, and usually the horizontal portion or threshold, is part of the shower floor pan structure. The curb may also extend along the stall perimeter past the area of the doorway, so as to allow other shower stall wall components to be mounted thereon (e.g. a glass wall portion). 
     Common shower stall construction usually begins with framing of the walls and floor with wood beams or other building material. The wood or other framing may include structures for soap dishes, must provide a level surface on which to place the shower pan, and the framing must also provide physical support for the curb under the shower stall doorway. Since the curb is at least partially comprised of a portion of the shower floor pan, the framing should provide a solid and tightly fitting support for the curb portion of the pan. Deformation of the shower floor pan, including the curb portion of the pan, that is caused by foot traffic if the supporting frame for the shower floor pan is not in tight contact with the shower floor pan, may result in breakage of the shower floor pan and resultant leaks out of the floor of the shower. The construction of the framing for a shower stall is a time consuming task that requires skill and care, as well as a correspondingly large expense. Errors in the framing may also not be detected until the shower stall is almost completed, at which time repairs are more costly and time consuming. The preparation of the waterproofjoint around the drain pipe is also a critical task that may require repair once the shower stall is finished and require excessive time and effort to repair. 
     Once a shower stall frame is constructed, a suitable wall material is usually placed over the framing that is above the pan in order to form the shower stall walls. A tile or other suitable surface is then placed over the wall material to form a waterproof surface above the shower floor pan. The similar or different tile or other surface is often also applied over the shower pan to form a finished floor for the shower. The tile or other material forming the finished floor must be formed so as to create an incline with the drain opening at the bottom so as to ensure that the water in the floor of the shower will drain. 
     SUMMARY OF THE INVENTION 
     It is an objective of the present invention to provide a pre-formed shower floor pan which provides sufficient structural rigidity so as to allow installation with a minimum of framing construction and other labor. 
     It is another object of the present invention to provide a low cost shower floor pan which can be easily installed in a shower stall. 
     It is a further object of the present invention to provide a shower floor pan that is strengthened in an area of more complex shape so as to reduce the likelihood of breakage of that area during transit and use. 
     The present invention achieves these and further objectives by providing a molded, one piece shower floor pan which has a preformed curb containing reinforcing ribs to provide required strength and structure for the shower pan curb. The shower pan of the present invention also utilizes an integrally molded shower drain. 
    
    
     Other objects, features and advantages of my invention will become more readily apparent upon reference to the following description when taken in conjunction with the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a shower stall utilizing the present invention with the rear side of the nearest wall exposed; 
     FIG. 2 is a bottom plan view of the underside of a shower pan of the present invention; 
     FIG. 3 is a cross-sectional elevational view of a shower pan of the present invention; 
     FIG. 4 is a top plan view of a shower pan of the present invention; and 
     FIG. 5 is a top view of an alternative configuration for a shower pan of the present invention. 
     FIG. 6 is a front elevational view of the modified configuration. 
     FIG. 7 is a bottom plan view of the embodiment of FIGS.  5  and  6 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The description of the preferred embodiments of the present invention will be aided by reference to the figures, wherein the same or similar components are identified by the same numeral. The present invention is intended for use in shower stalls which may have a variety of configurations and footprints. FIGS. 1 through 4 illustrate a shower stall with a square footprint, but the present invention may be utilized in shower stalls with any shaped footprint. 
     FIG. 1 shows the outside of a shower stall wherein the framing of the near wall may be seen. Framing wall studs  120  are generally placed vertically from the floor to the ceiling joints at evenly spaced intervals. The wall, which is framed by the wall studs  120 , generally encloses part of the shower stall. The shower stall shown in FIG. 1 has a wall enclosing three of the four sides with one side of the stall forming the stall opening  122 . Stall opening  122  may be covered with a shower curtain or glass door as is known in the art. 
     FIG. 1 shows a shower pan  101  with a shower pan floor  102 , a curb  105  and side walls  104 . Side walls  104  of the preferred embodiment are integrally molded into the shower pan  101  so as to form a water tight basin for the shower stall. The side walls  104  of the preferred embodiment are constructed so as to be substantially the same thickness as the wall material  121  that is placed over the wall studs  120 , or at least be oriented so that the surface thereof facing the drain opening is substantivally coplanar with the adjacent wall surface so that tiles or other wall covering material which will be used to cover the walls and floor of the shower space can be installed against both the interior surface of pan  101  and the adjacent, coplanar, wall surface  113 . Using the same thickness for the wall material  121  and the side walls  104  allows tile or other surface  113  to be continuously and seamlessly placed over the wall material  121  and side walls  104 . The side walls  104  may be the same height as the curb  105  or may extend higher or lower than the curb  105 . 
     FIG. 2 is a bottom cross-sectional view of the shower pan  101  taken along lines  2 — 2  of FIG.  3 . The side walls  104  and shower pan floor  102  are shown. The underside of the curb  105  is shown in detail. The curb  105  of the preferred embodiment comprises three wall portions, the inner vertical curb wall  106 , horizontal curb  107  and outer vertical curb wall  130 . The underside of the curb is not covered in the preferred embodiment. Reinforcing curb ribs  108  are shown as perpendicular to the three surfaces. The reinforcing curb ribs  108  are integrally molded into the singly molded shower pan  101 . The reinforcing curb ribs  108  provide added strength to the curb  105  so as to eliminate the need to construct additional support beneath the curb portion of the shower pan  101  at the construction site during installation of the shower stall. An outer vertical curb wall  130  is not required by the present invention, but a suitable surface to form the front of the curb is generally desired and including the outer vertical curb wall  130  in the integral molding will increase the strength of the curb  105 . The side walls  104  are shown as joining the shower pan floor  102  along the shower pan floor edge  103 . Side walls  104  are molded along with the shower pan floor  102  so as to form an integrally molded watertight structure. 
     FIG. 3 illustrates a cross-sectional elevational sectional view of the shower pan  101  showing the tapering floor  102 . A tile surface (not shown ) may be installed so as to form an incline with a lowest point at the drain opening  110 . FIG. 3 shows a drain pipe  111  entering through the drain opening  110  in shower pan floor  102  through a drain pipe joint  112 . In the preferred embodiment, the drain pipe joint  112  is formed by molding the shower pan floor  102  around the drain pipe  111 , as is known in the relevant arts. However, other techniques for placing the drain in connection with the pan are contemplated. The drain pipe joint  112  is a water tight connection between the shower pan floor  102  and the drain pipe  111  so that water captured by the shower pan floor  102  will not leak through the drain pipe joint  112 . Suitable drain holes may be included along the length of the drain pipe to allow water held by the shower pan floor  102  to drain, as is known in the art. The incline formed for the tile surface  113  may be made by building mortar up as the distance from the drain pipe  11  increases, or the floor  102  of pan  101  itself may be fabricated so as to present an inclined surface as shown in all drawing figures. 
     FIG. 3 further shows the arrangement of the components of curb  105 . The inner vertical curb wall  106  rises from the shower pan floor  102  and joins the horizontal curb wall  107  at the inner vertical curb wall&#39;s upper edge  109 . The outer vertical curb wall  130  connects at an upper edge thereof to horizontal curb wall  107  and terminates at a lower edge  131  which is substantially coplanar with the planar bottom surface  103  of pan floor  102 . 
     FIG. 4 illustrates a top-down view of the shower pan  101 . The curb  105  is shown to include an inner vertical curb wall  106 , a horizontal curb wall  107  and an outer vertical curb wall  130 . Side walls  104  are shown on the other three sides of the shower pan  101 . A drain pipe  111  is shown at the middle of the shower floor pan. 
     The pan  101  of this invention is, preferably, but not by way of limitation, manufactured by a rim molding process using polyurethane. Polyurethane offered by The Bayer Corporation under the designation “ 645 ” has been found to be particularly suitable. However, any material which demonstrates suitable strength, hardness, flow and creep characteristics is desirable. 
     In one embodiment, a drain reinforcement is employed in the form of a wire and fiberglass mesh  125  sandwiched within the floor  102  of pan  101 . This mesh is situated in surrounding relationship around drain opening  110 , and extends outwardly therefrom and may or may not be bonded to drain element  111 . In this way, drain opening  110  is reinforced so that drain element  111  will not tend to break away and/or leak. 
     It is obvious that the shower pan of the present invention may take on shapes other than the rectangle illustrated above. The shower pan of the present invention may also utilize a curb on more than one side of the pan. The shower pan of the present invention may also be formed with side walls  104  or curbs which are curved or curvilinear. 
     An example embodiment of an alternative shower pan shape is shown in FIGS. 5-7. The shower pan  201  shown in FIGS. 5-7 may be installed into a corner of a room, with the two room walls forming the corner mating with side walls  204  of the shower pan  201 . The resulting shower stall will have an opening opposite the two room walls formed by the curb  205  may be of any shape, such as curb  205  shown in FIG.  5 . This opening may be covered with a shower curtain or a glass wall/door combination as is known in the relevant arts. The shower pan shown in FIGS. 5-7 includes a continuous curb  205  with seamless horizontal curb upper surface  207 , inner vertical curb wall  206 , outer vertical curb wall  230 , and reinforcing ribs  208 , to, again, eliminate the need to use reinforcing member(s) below curb  205 . It can readily be appreciated that the more the footprint of the pan deviates from a rectangle, the more desirable it is to utilize the instant invention&#39;s pre-fabricated curb and reinforced rib structure so as not to require the construction of underlying support(s) for the curb  205 . A drain reenforcement mesh  225  may be integrated into the floor  202  of pan  201  to reinforce drain opening  210 . 
     Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.