Abstract:
A fume blocking drain cap could include a drain cap body having a top side and an underside defining at least one aperture extending therethrough and a dissolvable membrane attached to the underside of the drain cap body. The dissolvable membrane is arranged over the at least one aperture sealing the aperture from the underside of the drain cap body. A retainer ring may be provided that abuts the bottom surface of the dissolvable membrane to retain the dissolvable membrane against the underside of the drain cap body. The cap could also include a collar having an outside surface and inside surface. The collar is attached to and depends from the underside of the drain cap body and surrounds the dissolvable membrane.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to U.S. Provisional Patent Application No. 61/333,980, filed May 12, 2010, entitled “Fume Blocking Drain Cap”, which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to drains and drain caps and, more specifically, to drain caps designed to prevent odors from emanating therethrough. 
     2. Description of Related Art 
     Floor drains, such as those in a basement or on a manufacturing facility floor, serve the important purpose of preventing flooding of a floor. These types of drains take in a number of different liquids and often have grates associated with the drain openings which prevent large particles from entering the drain. However, oftentimes small particles can pass through the grates and become trapped in the piping and/or plumbing associated with the drain. These particles and any residual liquid that may adhere to the walls of the associated piping can cause unpleasant and foul odors to emanate from the drain through the grate. 
     One such device which attempts to overcome this problem is disclosed in United States Patent Application Publication No. 2007/0050901. This publication discloses a drain sealing ring comprising a resilient diaphragm. Draining liquids act against the resilient force of the diaphragm to pass through the drain. However, when liquids are not passing through the drain, the diaphragm is biased against the sealing ring to create an airtight seal. 
     United States Patent Application Publication No. 2007/0050901, like many other currently available devices designed to reduce drain odor, the publication discloses devices which involve complex mechanical or fluid dynamic principles. The present invention seeks to overcome this deficiency in the prior art. 
     SUMMARY OF THE INVENTION 
     In one embodiment of the present invention, a fume blocking drain cap could include a drain cap body having a top side and an underside defining at least one aperture extending therethrough and a dissolvable membrane positioned against the underside of the drain cap body. The dissolvable membrane is arranged over the at least one aperture, sealing the aperture from the underside of the drain cap body. A retainer ring may be provided that abuts the bottom surface of the dissolvable membrane to retain the dissolvable membrane against the underside of the drain cap body. The cap could also include a collar having an outside surface and inside surface. The collar is attached to and depends from the underside of the drain cap body and surrounds the dissolvable membrane. The retainer ring could be adapted to apply a biasing force against the inside surface of the collar. The retainer ring could be a resilient ring and have a diameter greater than a diameter of the inside surface of the collar. In this manner, the retainer ring could be positioned in the collar in a compressed state to apply a biasing force against the collar, fixing the retainer ring in place and retaining the dissolvable membrane against the underside of the drain cap body. 
     The retainer ring and the collar could be placed in an interference fit arrangement, for example, by providing a ring receiving recess defined on the inside surface of the collar, wherein the retainer ring is received within the ring receiving recess to engage the retainer ring with the collar. 
     The drain cap body could define a plurality of apertures, the dissolvable membrane arranged over the plurality of apertures sealing the apertures from the underside of the drain cap body. The dissolvable membrane and the drain cap body could be disk-shaped, wherein the dissolvable membrane has a diameter that is less than the diameter of the drain cap body. The dissolvable membrane could include a water soluble paper, which could be sodium carboxymethyl cellulose. The water soluble paper could include 80% sodium carboxymethyl cellulose and 20% wood pulp fibers. The dissolvable membrane could also include poly(ethylene oxide). The dissolvable membrane could be adapted to dissolve over a period of less than one second when brought into contact with liquid, such as water. In one embodiment, the dissolvable membrane could be at least 0.0085 inches thick. 
     Another embodiment of the present invention is directed to a fume blocking drain cap that includes a drain cap body having a topside and an underside and defining a plurality of apertures extending therethrough; a collar having an outside surface and inside surface, the collar being attached to and depending from the underside of the drain cap body, wherein the collar surrounds the dissolvable membrane; a dissolvable membrane comprising water soluble paper positioned against the underside of the drain cap body, wherein the dissolvable membrane is arranged over the plurality of apertures sealing the apertures from the underside of the drain cap body; and a resilient retainer ring abutting a bottom surface of the dissolvable membrane to retain the dissolvable membrane against the underside of the drain cap body. In this embodiment, the collar defines a ring receiving recess, and the retainer ring has a diameter greater than a diameter of the inside surface of the collar; the retainer ring is in a compressed state and positioned within the collar to apply a biasing force against the collar fixing the retainer ring in the ring receiving recess, retaining the dissolvable membrane against the underside of the drain cap body; and the dissolvable membrane is adapted to dissolve over a period of less than one second when brought into contact with liquid. 
     Yet another embodiment of the present invention is directed to a method of retrofitting a drain with a drain cap. The method includes obtaining a cap having a cap body having a top side and an underside defining at least one aperture extending therethrough; securing a dissolvable membrane to an underside of a drain cap body; and placing the cap into a preexisting drain. It could also include securing a retainer ring to an inside surface of a cap collar attached to the underside of the cap, and the step of positioning a dissolvable membrane could include securing the dissolvable membrane between the underside of the cap and the retainer ring. A ring receiving recess can be provided on the inside surface of the cap collar, wherein securing the retainer ring to an inside surface of the cap collar includes placing the retainer ring in the ring receiving recess. 
     Another embodiment is directed to a replacement drain membrane for securing to a drain cap having a drain cap body having a top side and an underside and defining at least one aperture extending therethrough. The membrane includes a dissolvable disk adapted to be positioned against the underside of the drain cap body and seal the at least one aperture from the underside of the drain cap body, wherein the disk comprises a thickness of at least 0.0085 inches, wherein the disk is dissolvable within a period of time in the range of 0 to 45 minutes when in contact with liquid. The dissolvable disk could be water soluble paper, for example sodium carboxymethyl cellulose. The water soluble paper could be 80% sodium carboxymethyl cellulose and 20% wood pulp fibers. The dissolvable disk could also be poly(ethylene oxide). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of the fume blocking drain device can be obtained by considering the following description in conjunction with the accompanying drawing figures in which: 
         FIG. 1  is a top view of a fume blocking drain cap according to one embodiment of the present invention; 
         FIG. 2  is a side view of the fume blocking drain cap of  FIG. 1 ; 
         FIG. 3  is an exploded cross-sectional view of the fume blocking drain cap of  FIG. 1  taken on the line III-III; 
         FIG. 4  is an assembled view of the cross-sectional view of the fume blocking drain cap of  FIG. 3  positioned in a floor drain; 
         FIG. 5  is the cross-sectional view of  FIG. 4  without a membrane according to the present invention; 
         FIG. 6  is a bottom view of the fume blocking drain cap of  FIG. 1 ; 
         FIG. 7  is a bottom view of the fume blocking drain cap of  FIG. 1 , including an alternative embodiment of a retainer ring; 
         FIG. 8  is a top view of another embodiment of a fume blocking drain cap according to the present invention; and 
         FIG. 9  is a side view of the fume blocking drain cap of  FIG. 8 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     For purposes of the description hereinafter, spatial orientation terms, if used, shall relate to the referenced embodiment as it is oriented in the accompanying drawing figures or otherwise described in the following detailed description. However, it is to be understood that the embodiments described hereinafter may assume many alternative variations and embodiments and that the specific embodiments illustrated in the accompanying drawing figures and described herein are simply exemplary and should not be considered as limiting. 
     As shown in  FIGS. 1-2 , in one embodiment of the present invention, a fume blocking drain cap  10  may comprise a drain cap body  20 , a retainer ring  30 , a collar  40 , and dissolvable membrane  50 . The retainer ring  30  is shown in broken lines on  FIG. 1 , which is a top view. The drain cap body  20  includes a top side  24  and an underside  26  with at least one aperture  22  or, as shown in the drawings, a plurality of apertures  22  defined therethrough for allowing drain liquids to pass through the drain cap body  20 . The cap  10  also includes a dissolvable membrane  50 , which is explained in more detail below. 
     Referring now to  FIG. 2 , the collar  40  may be attached to and depend from the underside  26  of the drain cap body  20  to surround the dissolvable membrane  50 . The collar  40  may be a separate component. For example, the collar  40  and the drain cap body  20  may be constructed as two separate materials. Preferably, however, the collar  40  and the drain cap body  20  are formed of a single, integrally molded or extruded component, for example, polyvinyl chloride (PVC) or cast aluminum. Also shown in  FIG. 2 , in broken lines, are membrane  50  and retainer ring  30  abutting the bottom surface of the dissolvable membrane  50 . The retainer ring  30  is positioned in a ring receiving recess  44  defined in an inside surface  42  of the collar  40 , as shown by the broken lines of  FIG. 2 . 
     Referring now to  FIGS. 3-5 , the membrane  50  is positioned against the underside  26  of the drain cap body  20 , arranged such that it covers and seals the apertures  22  from the underside  26  of drain cap body  20 . The membrane  50  is retained against the underside of the drain cap  20  by retainer ring  30 , which abuts the bottom surface  52  of the membrane  50  securing the membrane against drain cap body  20 . The retainer ring  30  can be received into a ring receiving recess  44 , as best shown in  FIG. 3 , defined on the inside surface  42  of the collar  40  to engage the retainer ring  30  with the collar  40  in an interference fit arrangement. The diameter d 1  of the retainer ring  30  could be greater than the diameter d 2  of the inside surface  42  of collar  40 . In this manner, the retainer ring  30  could be constructed of a resilient material, such that retainer ring  30  could be compressed to fit into ring receiving recess  44 , wherein subsequent expansion of the retainer ring  30  will cause a biasing force F to be exerted by the retainer ring  30  against the inside surface  42  of the collar  40 , as shown in  FIG. 4 . Accordingly, the retainer ring  30  is fixed in place, biasing the bottom surface  52  of the membrane  50 , thereby retaining the membrane  50  against the underside  26  of the drain cap body  20  and maintaining a seal over the apertures  22 . As shown in the bottom view of  FIG. 7 , the membrane  50  seals the apertures  22 , which are shown in broken lines, from the underside  26  of the drain cap body  20 . 
     The dissolving membrane  50  may be disk-shaped, thereby mirroring the shape of the drain cap body  20 , shown in  FIGS. 1-5 , which may also be disk-shaped. However, any shape or thickness for a particular application is contemplated by the present invention. 
     As shown in  FIG. 3 , the drain cap body  20  may have a diameter d 3  with the remaining components of the fume blocking drain cap  10 , i.e., the retainer ring  30 , the collar  40  and the membrane  50 , having a diameter less than that of the drain cap body  20 , e.g., diameter d 2  of collar  40  and diameter d 1  of retainer ring  30 . The diameter of the drain cap body  20  could range, for example, between 3 and 5 inches. 
     The dissolving membrane  50  may be manufactured from an industrial soap material, such as a soap material from the oil and gas industry. Two materials that may be used to form the membrane are a water soluble paper or poly(ethylene oxide). These materials are commercially available and can be obtained, for example, from Aqua-Clear, Inc. of Charleston, W. Va. The water soluble paper may comprise a composition of approximately 80% sodium carboxymethyl cellulose and 20% wood pulp fibers. The paper may be approximately 0.0085 inches thick. Depending on the material and/or thickness of the membrane  50  used, the dissolve rate may vary. When in contact with water or another liquid, the membrane  50  may dissolve over a range of time varying from instantly to approximately forty-five minutes. A 0.0085 inch thick single layer of water soluble paper membrane may dissolve immediately upon contact with liquid, for example, less than one second. Poly(ethylene oxide) soap, on the other hand, may require between 30 and 40 minutes to dissolve after coming into contact with water or another liquid. The poly(ethylene oxide) soap is more optimized for salt water applications. These materials are environmentally harmless and will not cause damage or be toxic to a drainage system. 
     When installed in a drain  65  in a floor  60 , as shown in  FIGS. 4-5 , the collar  40  will extend into drain piping  70 , with the retainer ring  30  biasing against the inside surface of the collar  40 . Because the membrane  50  seals the apertures  22  from the underside of the drain cap  20 , fumes and odors, represented by arrows  75 , will be incapable of emanating from the piping  70  of the drain  65  in floor  60 . 
     Referring now to  FIGS. 4-5 , in use, the drain cap  10  may be a floor drain, for example, on the floor  60  of a manufacturing facility. Oftentimes, flooding on the facility floor may occur due to leakage, spillage, or other hazards. When this occurs, the hazard liquid  80  will pool, as illustrated in  FIG. 4 , at a point near the drain cap  10  because the apertures  22  of drain cap body  20  will be sealed by the membrane  50 . Therefore, the liquid will contact the membrane  50 , as opposed to draining immediately through the apertures  22 . After a short period of time, which may, for example, be instant to approximately 30 minutes, depending on the membrane material and thickness used, the membrane  50  will dissolve due to its exposure to the liquid  80  through apertures  20 . The liquid  80  can then drain, thereby disposing of the flooding hazard. A drain cap  10  after the membrane  50  has been dissolved and the liquid  80  allowed to drain is shown in  FIG. 5 . If an industrial soap material is used, the membrane  50  may only dissolve at points that correspond to the apertures, and residual membrane  50  will remain on the underside of the drain cap  20 . The drain cap  20  may then be removed and the dissolved membrane  50  replaced, by removing the retainer ring  30  from within collar  40  and removing what remains of the dissolved membrane  50 . A new membrane  50  may then be placed against the underside of the drain cap  20 , thereby resealing the apertures  22  of the drain cap  20 . In the case of water soluble paper, the entire membrane  50  is likely to dissolve, including the portions not in direct contact with the liquid via the apertures  22 , such as illustrated in  FIG. 5 . In this case, the residual membrane will not need to be removed and a new membrane  50  may simply be placed against the underside of the drain cap  20  after removing the retainer ring. Accordingly, odors and other hazardous fumes and contaminates, either sent down the drain with the flood liquid  80  or previously present in the drain piping, will not emanate through the apertures  22  of drain  20  due to the seal produced by membrane  50 . 
     As shown in  FIG. 7 , in an alternative embodiment, retainer ring  30 ′ may comprise a spring-loaded open-ended coiled ring. When the spring loaded retainer ring  30 ′ is placed inside the collar  40 , it is compressed by coiling it to fit within the collar  40 . The ring  30 ′ then subsequently expands, thereby engaging a chamfer  44  on the inside surface of the collar  40  and applying a biasing force against the inside surface of the collar  40 , such that the retainer ring  30 ′ is fixedly maintained in position like retainer ring  30 , shown in  FIGS. 1-6 . 
     Referring now to  FIGS. 9-10 , an alternative embodiment of a drain cap  10 ′ is shown. This embodiment includes a different arrangement of the plurality of apertures  22 ′ than that of the drain cap  10  in  FIGS. 1-7  and an extended collar  40 . As shown, the apertures  22 ′ are square-shaped, as opposed to the circular apertures illustrated in  FIGS. 1-8 . Other than these specific differences, the construction and operation of drain cap  10 ′ is substantially identical to that of drain cap  10  explained above. 
     The above-described fume blocking drain caps may be retro-fitted to an existing drain, wherein, for example, the drain cap body  20  may be a universal drain cap used in conjunction with a pre-existing drain, with the remaining components, the retainer ring  30 , the collar  40 , and the membrane  50 , being subsequently attached thereto. Alternatively, the entire fume blocking drain cap  10  may be manufactured as a complete retro-fit cap, completely replacing a pre-existing drain cap in conjunction with a pre-existing drain. 
     While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. The presently preferred embodiments described herein are meant to be illustrative only and not limiting as to the scope of the invention, which is to be given the full breadth of the appended claims and any and all equivalents thereof.