Abstract:
A shower trench drain apparatus includes a shower trench drain body of polymeric material having an integrally-formed drain channel with angled bottom surface and drain opening or openings, a waterproof membrane over the drain body, a clamp ring retaining the membrane to the drain body, and a grate adjustably retained to the drain body by a height adjustment mechanism. The trench drain body formed from a block of material such as PVC or ABS, which are compatible with approved plumbing materials and codes. The block has a flat bottom adapted for horizontal support during installation and includes integrally-formed features facilitating adjustment during installation while minimizing components and separate parts and simplicity of installation.

Description:
BACKGROUND 
       [0001]    The present invention relates to shower drains, such as are often used in residential, commercial, and institutional shower constructions. 
         [0002]    Typical tiled showers must by code and design have a slope that moves the water from all floor surfaces to the drain. A normal shower configuration would be a square, rectangle, or a polygon. Those configurations mandate four or more triangular shaped quadrants all converging at the drain. Modern day designs have mandated larger overall size showers and more complex base configurations. The larger the shower foot print, the longer the slope. However, these configurations cause problems as noted below. 
         [0003]    Each sector of these polygons creates an intersecting plane that creates problems for the setting of tile on the base. Even with small tile or stone (2″×2″), these changes in plane make the finished floor show these changes in plane, which can be aesthetically unacceptable and further can lead to leak problems at lines of intersection. For example, historically the drain is most often placed at the common vertex of these polygons. With the design world trending to larger format tile, the setting of tile with intersecting planes creates a virtually impossible situation for the tile setter due the changes in plane. In addition, many designs go to single slabs of stone for the shower base. This creates a problem for the installation since all drains are designed to be parallel to the subfloor. 
         [0004]    A trench drain at the outboard side of one of the peripheral sides of the configuration can solve this problem. It is still necessary to provide the appropriate slope as listed in the plumbing code. However, since the intersecting planes have been eliminated, the size tile used as a finished surface is now not a factor. This opens up the options in both the design and materials that can be used. 
         [0005]    Trench drains have been used in outdoor applications by the construction industry for many years. The most common usage is slab on grade applications, such as at the edge of parking lots and building entrances. These applications do not require 100% leak integrity since the ground fill surrounding the drain absorbs any leakage that occurs. These type trench drains are typically manufactured in a variety of linear processes in plastic and various metals. The drain is cut and assembled in sections with end caps at the ends of a run. 
         [0006]    While the concept for shower trench drains is similar, the requirement that the installation be 100% waterproof is mandated by code. Since the vast majority of applications are over occupied space, the watertight integrity of the drain system is critical and flood testing is required by most plumbing codes. 
         [0007]    There are some existing trench drains for buildings. Most are constructed of variety of grades of stainless steel, and include drain bodies constructed from combinations of cut segments welded together or stampings with additionally welded components. Due to the large number of sizes required by the design community, the ability to build multiple size dies for the drain bodies is not cost effective. Thus, components in known existing trench drain configurations are typically welded. However, welding is expensive and can lead to leak problems. For example, many times welding is the cause for small undetectable leaks that lead to water problems in the field that will not be noticed for many years, at a time when they have already created considerable problems such as rotted under-floor structures and smells associated with wet moldy environments. Notably, leaks can occur at the welds either at the time of manufacture, or during or after installation. These leaks can increase over time (or show up for a first time), due to corrosion and/or stress during installation and/or fatigue and/or from material stress caused in part by the welding. Quality control of welding is difficult, time consuming, and can add considerably to manufacturing expense, particularly where the welding extends 360 degrees around a pipe or connection. It is noted that shower trench drains are unforgiving, in that the water being drained away will find all leaks, and will eventually cause a problem. 
         [0008]    Additionally, most known shower trench drains have trench bodies that are made of sheet metal formed with multi-angled surfaces, making them difficult to accurately position during an installation. Specifically, every trench body must have a specific slope for adequate water drainage. The mandated slope in the trench body (with constant wall thickness) leaves a bottom of the drain body on an angle to the drain opening. This occurs since the sheet material of known trench bodies has a uniform constant wall thickness. This factor leads to difficult installations since the drain body needs to be supported by dry packed mortar (or adjustable jacks that are left in the mortar bed) at a perfect sloped angle. It is not easy to form dry packed mortar at a perfect sloped angle, as required to support the known shower trench drain bodies. Molded trench drains also have a similar problem. Specifically, trench drains that are molded from thermoplastic materials effectively have the same issues since constant-thickness wall design is a typical requirement for injected molded designs. 
         [0009]    Known existing trench drains are commonly constructed in straight length configurations from 24 to 72 inches. Whether the drain is made from metal or plastic material, the costs to tool the numerous sizes is often cost prohibitive. Complex configurations other than straight are generally too complex to fabricate in metal, except by welding as noted above, since their low volume manufacture makes it cost prohibitive to invest in expensive capital-intensive tooling. 
       SUMMARY OF THE PRESENT INVENTION 
       [0010]    In one aspect of the present invention, a shower trench drain apparatus includes a water collecting trench drain body with a block of material compatible with approved plumbing materials and codes and that is formed to include a drain channel with angled bottom surface. 
         [0011]    In another aspect of the present invention, a shower trench drain apparatus comprises a water collecting trench drain body including a block of material having a flat bottom adapted for horizontal installation and an integrally-formed up-facing drain channel with angled bottom surface. 
         [0012]    In another aspect of the present invention, a shower trench drain apparatus includes a shower trench drain body of polymeric material having an integrally-formed drain channel with angled bottom surface and drain opening, a waterproof membrane over the drain body, a clamp ring retaining the membrane to the drain body, and a grate adjustably retained to the drain body by a height adjustment mechanism. 
         [0013]    In another aspect of the present invention, a method of constructing a shower trench drain apparatus comprises steps of forming a shower trench drain body of polymeric material including a flat bottom surface, an integrally-formed drain channel with angled bottom surface and a drain opening. The method further includes steps of supporting the body on a flat support surface in an installation, laying a waterproof membrane over the drain body, clamping the membrane onto the body using a clamp ring, and attaching a grate adjustably to the drain body with an adjusted height that matches a final floor surface of a shower. 
         [0014]    The present system has several advantages including: very waterproof (especially given a lack of welds on metal drain components), foolproof in terms of installation, cost effective given the few and simple components, mates well with existing shower drain systems. The trench body made by a formed plastic block is seen as a real advantage given the low volume of these parts, since it can be manufactured on a just-in-time basis (which minimizes inventory cost and tooling investment), such as by being machined with CNC equipment. 
         [0015]    These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0016]      FIG. 1  is an exploded perspective view of the present shower trench drain apparatus; and  FIG. 2  is a side cross sectional view of an assembly of the components in  FIG. 1 . 
           [0017]      FIGS. 2A ,  3 - 6  are perspective, top, side, bottom, and end views of the assembled shower trench drain assembly of  FIGS. 1-2 . 
           [0018]      FIGS. 7 and 8  are cross sections taken along lines VII-VII and VIII-VIII in  FIGS. 3 and 4 , respectively. 
           [0019]      FIG. 9  is a perspective view of an end of a shower trench drain assembly. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0020]    The present shower trench drain apparatus includes a trench body constructed from a single block of material machined to its final shape including various integral features. It is contemplated that the material will typically be selected to be a polymer such as PVC (Poly Vinyl Chloride) or ABS (Acrylonitrile butadiene styrene). A reason is because these materials are capable of being machined in addition to being compatible with common types of rigid pipe used in the plumbing industry. Further, it is noted that PVC and ABS materials are widely available in large format sheets with many available thicknesses. This allows the construction of complex design shapes by CNC machining with the only limitation being the overall dimension of the raw block. The present inventive concepts are based in part on the premise that it is far more cost effective (for manufacturing, installation, and durability reasons) to design and manufacture configurations into a block of material than it is to cut, stamp and (reliably) weld an even walled metal material of constant thickness. Notably, the present trench body has a flat horizontal bottom surface, which greatly facilitates installation since preparation of the supporting material for the trench drain body (i.e., mortar or other material) only requires making it horizontally level/flat, as noted below. 
         [0021]    Since the drain is formed from a single block of plastic, the configurations are only limited to creativity of the designer. This allows for the ability to create complex polygons with multiple drain slopes and drain openings. CAD (Computer Assisted Design) and CAM (Computer Assisted Manufacturing) make design and manufacturing very feasible. In addition, the PVC and ABS materials used in the drain construction are able to be directly solvent welded (or adhesively bonded) to common rough in drain pipes. This eliminates the need for special adapters to connect the drain body to the rough in drain pipe. This is potentially very important, since solvent welding (and adhesively bonding) can create very high quality and easily formed joints that are leak-proof and with high long-term reliability of the absence of leaks. 
         [0022]    The present apparatus incorporates a flat bottom surface on the drain body itself. This allows for direct mechanical attachment to the subfloor without the need for leveling mechanisms or shims or jacks found in conventional metal trench drains. In addition this eliminates the need to cut away the subfloor in order to allow for the code mandated slope on the drain interior. 
         [0023]    The present apparatus can be used in both mortar bed and thin-bed applications since the drain bottom is always flat. Since many thicknesses of tile and stone are available, this invention incorporates the feature of multiple standoffs to adjust the finish drain cover to the same plane as the top of the drain cover. This is critical to the final appearance of the shower floor and the function of the drain. It can adjustably accommodate the additional thickness for the material that is used to bond the tile to the shower floor substrate. 
         [0024]    Additionally, the present apparatus can incorporate a pre-drain strainer that collects soap residue, hair and other matter that is not collected by the finish cover or grate. The pre-drain strainer can be constructed of plastic or metal and is located prior the drain opening. It incorporates a series of holes that allow for the water to pass through to the drain hole, but collect any foreign matter that makes it to that point. This feature allows for cleaning foreign matter from the drain by just removing the drain cover, and clearing or dumping the pre-drain strainer. This feature also reduces the frequency of need for using a plumbers snake to clean the system. It also reduces maintenance issues in both residential and large commercial applications. 
         [0025]    Since watertight integrity is needed any all shower applications, the present apparatus incorporates a mechanism for sealing and mechanically locking the waterproof membrane to the drain body. The design includes a continuous channel of a semi-circular configuration formed on the top of the trench drain body adjacent to the perimeter of the water collection containment portion of the drain body. This channel is filled with an appropriate waterproof elastomeric sealant. NobleSealant  150  is an example of a proper sealant. A stainless steel clamping ring seal is fastened to the drain body by the means of small self tapping stainless steel screws. The section of material below the clamping ring is depressed to create a downward flow of drain water to the collection chamber of the drain body. 
         [0026]    The waters exit point (i.e., drain outlet opening) is generally in the center of the collection chamber, but can be placed at any point in the collection chamber as long as the slope directs the water to the exit point. The illustrated drain body has an exit point constructed in a manner that allows the rough in drain pipe to be solvent welded to the drain body without the use of separate plastic fittings. 
         [0027]    A drain cover (or grate) of typically stainless steel covers the water collection chamber. The drain cover is shaped in a c-channel configuration to improve its rigidity. It is both functional and decorative and can be constructed with openings and patterns forming unique/aesthetic designs and finishes. A number of integral standoff bosses are incorporated into the collection chamber of the body. Stainless steel screws adjustably engage these bosses allow the strainer cover to be brought level to the finish floor. After the cover is properly adjusted to the proper height, additional screws are used to mechanically fasten the cover to the drain body and fix its height. 
         [0028]    In regard to the drawings, the illustrated shower trench drain assembly  20  ( FIGS. 1-2 ) includes a shower trench drain body  21 , a waterproof sheet liner  22 , a clamp ring  23 , and a cover or grate  24 . The drain body  21  is placed at a side of the shower floor and embedded to be flush with a slightly-angled planar floor. The drain body  21  is a relatively-thick block of plastic material, such as 1-4″ high, 4-6″ wide if it is straight drain design, and several inches long, such as 6 to 96 inches, and is PVC or ABS or similar plastic. The slab is substantially free of stress so that the block does not warp when machined, nor warp over time after installation. (Stress free blocks of PVC and ABS are commercially available.) A clamp ring recess  25  is formed around and into a top of the block, and a drain channel  26  is also formed into the top. The clamp ring recess  25  is configured to receive a sealant material or a gasket to create a pliable permanent seal around the opening cut into the sheet liner  22  over the drain channel  26  in drain body  21 , and cooperates with the mechanical clamp mechanism to further assure a leak-proof assembly and installation. The drain channel  26  includes an angled bottom surface  27  that angles toward a center drain hole  28  and a plurality of screw-receiving bosses  29  are formed around edges of the drain channel  26 . Pilot holes are drilled in the drain body to receive self tapping standoff screws. A sheet of water proof material liner  22  is placed on the drain body  21  and extends across the entire shower floor. The clamp ring  23  clamps the liner  22  onto the drain body  21 . An inside area is cut away to expose the drain channel  26 . The grate  24  includes welded-on components  32  with holes through which threaded screws  33  are extended and that extend downward to mechanically hold the cover in place. (It is noted that the welded-on components  32  are above the liner  22  and inside the channel of the body  21 , such that they cannot cause a water leak problem.) The drain cover height adjustment screws  33  engage the holes  30 . A top surface of the grate  24  lies flush to a shower floor once ceramic tiles  36  are installed on the shower floor. 
         [0029]      FIGS. 2A ,  3 - 6  are perspective, top, side, bottom, and end views of the assembled shower trench drain assembly  20 , and  FIGS. 7 and 8  are cross sections taken along lines VII-VII and VIII-VIII in  FIGS. 3 and 4 . 
         [0030]      FIG. 9  is a perspective view of an end of a shower trench drain assembly  20 . Illustrated is a clamp ring  23  held in place with screws, and a grate  24  held to the bosses  29  with separate screws. The grate  24  is supported above the remainder of the assembly, so that its top surface is flush with the shower floor once ceramic tiles are installed. 
         [0031]    It is contemplated that the present inventive apparatus can include additional features and accessories, such as a pre-drain strainer  35  that fits into slotted weir holder  37 . The pre-drain strainer  35  ( FIGS. 1-2 ) can be constructed of plastic or metal, and is located prior the drain opening. It incorporates a series of holes that allow for the water to pass through to the drain hole, but that allow the strainer to collect any foreign matter that makes it to that point. This feature allows for cleaning foreign matter from the drain by just removing the drain cover. This feature also reduces the frequency of need for using a plumbers snake to clean the system set into the channel  26 . The strainer  35  can have a shape similar to the channel  26  and be similar in length (or shorter). It would be hidden under the cover or grate  24 , but would be easily removable upon removing the cover. Alternatively, it is contemplated that arrangements could be made so that the strainer set into the cover and was removable without first removing the cover. 
         [0032]    Notably, it is contemplated that a scope of the present invention includes any manufacturing method or process of manufacture for forming the trench body, such as by injection molding, casting, or other manner. Further, it is contemplated that a scope of the present invention includes any unitary trench body as formed with flat bottom or with cored standoffs and integral sloped water-channeling surface, regardless of the manufacturing method. 
         [0033]    It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.