Abstract:
An internal trap drain with large volume/high mass water seal for improved absorption of pressure fluctuations and extended duration of seal against evaporation in low-use conditions. Includes adjustable height strainer and water seal-protected weep holes.

Description:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0001]    Not Applicable 
       REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX 
       [0002]    Not Applicable 
       BACKGROUND OF THE INVENTION 
       [0003]    In steel shipbuilding, drains with internal trap, such as are shown in U.S. Pat. No. 558,569 by Sanders, U.S. Pat. No. 873,120 by Dunstan, U.S. Pat. No. 1,411,125 by O&#39;Brian, U.S. Pat. No. 2,603,304 by Carrier, U.S. Pat. No. 3,042,210 by Hattori, U.S. Pat. No. 4,487,219 by Mäkelä et al, U.S. Pat. No. 4,922,948 by Van Dijk, and in particular U.S. Pat. No. 7,122,117 by Goldring et al are used because they are vertically more compact due to no p-trap requirement, and because these types of drains are more resistant to loss of trap seal resulting from listing of the ship. In U.S. Pat. No. 4,026,317, Ekstrom describes his trap drain as one which provides a “tortuous path” for the waste stream across multiple water seals, which each add resistance one to the next, resulting in greater absorption of pressure fluctuations while preserving seal integrity, as well as extending the time period in which an unused drain will lose seal due to evaporation. In U.S. Pat. No. 180,859 Falk talks about “widening and enlarging” the trap to oppose a larger volume of water to the sewer gases. 
         [0004]    The aforementioned patents demonstrate the utility of the trap-in drain arrangement as well as the mechanism for reinforcing the trap seal through higher volume/mass of water against pressure fluctuations and as a means to increase trap seal endurance against evaporation. What is not found is a drain which incorporates trap-in-drain configuration along with adjustable height strainer and high-mass reinforced water seal. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    The present invention is an internal trap drain with strainer height adjustability and high-mass water seal incorporating more than twice as much volume of water as compared against a common p-trap. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0006]    A more complete appreciation of the invention will be obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: 
           [0007]      FIG. 1A  shows a top plan view of the Internal Trap Drain with Adjustable Height Strainer and High Mass Seal with respect to the present invention. 
           [0008]      FIG. 1B  shows a cross-sectional view of the Internal Trap Drain with Adjustable Height Strainer and High Mass Seal taken along line A-A of  FIG. 1A  with respect to the present invention. 
           [0009]      FIG. 2A  shows a front elevation view of the Internal Trap Drain with Adjustable Height Strainer and High Mass Seal with respect to the present invention. 
           [0010]      FIG. 2B  shows a cross-sectional view of the Internal Trap Drain with Adjustable Height Strainer and High Mass Seal taken along line B-B of  FIG. 2A  with respect to the present invention. 
           [0011]      FIG. 3  shows a view of outer bowl  1 , in which the top surface of flange  3  is visible with respect to the present invention. 
           [0012]      FIG. 4  is an enlarged view showing weep holes  16  and weep tube connection sockets  15  in top cover  5  of the Internal Trap Drain with Adjustable Height Strainer and High Mass Seal with respect to the present invention. 
           [0013]      FIG. 5  is an exploded view of the Internal Trap Drain with Adjustable Height Strainer and High Mass Seal with respect to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0014]    The drain is comprised of outer bowl  1 , inner bowl  4 , top cover  5 , and strainer assembly  6 . Outer bowl  1  has a piping connection  2  which serves as the drain outlet. Outer bowl  1  also has flange  3  which enables mounting the top cover through circumferentially located tapped holes  7  and corresponding countersunk through holes  8  in top cover  5  by means of flat head screws (not shown). In addition, flange  3 -to-top cover  5  connection is sealed by gland  9  and O-ring  10 . 
         [0015]    Inner bowl  4  has threaded cleanout opening  11  at its base and polished spillway edge  12  at its upper perimeter. Three radially spaced supports  13  extend from the outside surface of inner bowl  4  and terminate in a curved shape which conforms to the interior surface of outer bowl  1 . 
         [0000]    Supports  13  maintain the position and attitude of inner bowl  4  as axially aligned with outer bowl  1  and maintain space  14  between the outside of inner bowl  4  and the inside of outer bowl  1 . Upper edge  12  is polished to minimize solids accumulation as wastewater overflows edge  12  and flows through space  14  to drain opening  2 . 
         [0016]    In addition to through holes  8  for mounting and sealing to flange  3  of outer bowl  1 , Top cover  5  has weep tube attachment sockets  15  which provide both weep holes  16  at the top surface of top cover  5  as well as connection sockets  15  for weep tubes  17 , which extend down below the surface of the wastewater into inner bowl  4 . Top cover  5  also has threaded hole  18  located at its center and threaded hole  18  is of the size and thread gauge to accommodate male threads  19  which form the exterior surface of the cylindrical portion of strainer assembly  6 . 
         [0017]    Threaded cleanout plug  20  along with rubber washer  21  is in place to close off threaded cleanout opening  11  in inner bowl  4 , and is available for removal through the strainer assembly for cleanout when necessary. 
         [0018]    As wastewater enters strainer assembly  6  it rises to edge  12  of inner bowl  4 . Any additional water entering will cause a corresponding volume of water to spill over edge  12  and flow through space  14  to drain outlet  2 . While the water level is at the height of edge  12 , a water seal is established between the sewer gasses at the drain opening and strainer assembly  6  inlet. Weep holes  16  are also protected by the water seal. The gas cannot pass gland  9  and O-ring  10  and by applying thread sealant to male threads  19  the drain is rendered gas tight.