Patent Abstract:
An embodiment providing one or more improvements includes a trap primer with upper and lower chambers separated by a flexible diaphragm which also interacts with a valve stem to start and stop the flow of water from the trap primer to the trap(s). The lower chamber contains a polymeric foam medium such as a foam ring containing closed cells containing gas or gases. In use, equilibration of water pressures in the upper and lower chambers causes distortion of the foam ring, resulting in equilibration of the gas pressure in the closed cells with that of the chambers. A decrease in line water pressure causes water from the lower chamber to be emitted into the traps.

Full Description:
BACKGROUND OF THE INVENTION 
     Field of the invention 
     This invention relates to drain trap primers in which a gas under pressure is utilized to displace a liquid and a definite coaction exists between the gas and liquid which affects the system. 
     BRIEF SUMMARY OF THE INVENTION 
     Drain traps are essential in preventing the entry of poisonous sewer gas into buildings. Such traps are essentially U-shaped portions of drain pipes which fill with water from the drain and thereby prevent passage of sewer gasses from a sewer into the drain and into the building. Unfortunately, when the drains are used only infrequently, the water in the traps tends to evaporate, thus exposing the users of the building to sewer gasses. 
     Trap primers periodically replenish the water level in the drain traps and prevent the drying through evaporation of drain traps. Prior art trap primers replenish the drain traps using water from a building&#39;s water supply pipe. Such primers release water to the drain traps in response to fluctuations in the pressure in the supply pipe, which result from a draw on water from the supply pipe, such as opening a faucet, or flushing a toilet. 
     Some prior art trap primers contain chambers containing compressed air at a pressure which equilibrates with the water pressure in the supply pipe. When the water pipe pressure momentarily fluctuates, the compressed air opens a valve which allows water to flow from the trap primer into the trap or traps. In some prior art trap primers in which water is in contact with the compressed air, there is a tendency for the air to dissolve into the water, thereby reducing the volume of compressed air with an increase in the volume of water in the air chamber, until the primer fails to function properly. In other prior art primers the compressed air is separated from the water by a moving piston. Such arrangements are susceptible to binding and malfunction of the moving parts due to water borne residues and corrosion of the parts. 
     In embodiments of the present application compressed gas in closed-cell polymeric foam, in combination with a anti-oscillation valve, is used to open a membrane to valve in response to fluctuation of water supply pressure. Embodiments include an optional cleaner probe. Embodiments include an optional distributor to serve a multiplicity of water traps. Embodiments provide trap primers which are reliable, inexpensive, and easy to manufacture. 
     Embodiments include a trap primer for maintaining water levels in a drain trap in a building having a water supply line comprising a connection to the building water supply line, an upper chamber, an anti-oscillating valve located between the supply line and the upper chamber, a lower chamber having a bottom and a circumferential upper edge, the upper and lower chambers separated by a flexible diaphragm, a valve stem extending vertically from the bottom to the upper edge of the lower chamber, the valve stem having a bore with an orifice at the upper end, and a port leading to a trap at the lower end, the diaphragm reversibly sealing the valve stem orifice, and a closed-cell polymeric foam medium, the cells containing a gas, the foam medium located in the lower chamber. 
     The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tool and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements. 
     In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following descriptions. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         FIG. 1  is a perspective view of an embodiment trap primer with optional attached outlet distributor. 
         FIG. 2  is a cross-sectional view of the embodiment trap primer of  FIG. 1  taken at line  2 - 2 . 
         FIG. 3  is a cross-sectional view of the embodiment outlet distributor of  FIG. 1  taken at line  3 - 3 . 
         FIG. 4  is a cross-sectional view of the embodiment trap primer of  FIG. 1  taken at line  2 - 2  showing the start-up of the trap primer. 
         FIG. 5  is a cross-sectional view of the embodiment trap primer of  FIG. 1  taken at line  2 - 2  showing the trap primer under conditions of stable line pressure. 
         FIG. 6  is a cross-sectional view of the embodiment trap primer of  FIG. 1  taken at line  2 - 2  showing the behavior of the trap primer when there is a decrease in the line pressure. 
         FIG. 7  is a cross-sectional view of the embodiment trap primer of  FIG. 1  taken at line  2 - 2  with the cleaning lever and probe showing the action of the cleaning lever and probe. 
         FIG. 8  is an exploded view of the components of an embodiment trap primer without the cleaning lever and probe. 
         FIG. 9  is a perspective view of the rim of the lower chamber of an embodiment trap primer. 
         FIG. 10  is a perspective view of the anti-oscillation valve disk. 
         FIG. 11  is a perspective view of the flexible diaphragm. 
         FIG. 12  is cross-sectional view of the embodiment trap primer of  FIG. 1  taken at line  2 - 2  showing the second embodiment foam medium or foam disk located in the lower chamber. 
         FIG. 13  is cross-sectional view of the embodiment trap primer of  FIG. 1  taken at line  2 - 2  showing the third embodiment foam medium or foam particles located in the lower chamber. 
         FIG. 14  is a perspective view of the fourth embodiment resilient gas enclosure or bubble chamber. 
         FIG. 15  is a cross sectional view of the fourth embodiment resilient gas enclosure or bubble chamber taken at line  15 - 15  of  FIG. 14 . 
         FIG. 16  is a cross-sectional view of the embodiment trap primer of  FIG. 1  taken at line  2 - 2  showing the fourth embodiment resilient gas enclosure or bubble chamber located in the lower chamber. 
         FIG. 17  is a cross-sectional view of the second embodiment cylindrical upper body. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In this disclosure the term “resilient gas enclosure” (RGE) means material manufactured of a resilient polymer containing a gas. When the RGE takes the form of a foam, such materials comprise independent, non-communicating cells of a resilient polymeric material, such as a polyurethane, polyvinyl chloride, polystyrene, polyimide, or silicone. When the RGE takes the form of a foam, cells in the foam are formed during manufacturing using blowing agents, such as CO 2 , N 2 , or air. A suitable RGE closed-cell polymer foam is polyurethane with closed cells containing CO 2  gas. In embodiments, the RGE takes the form of a hollow, gas containing sealed structure with impermeable resilient walls made of suitable polymers, such as those listed above and containing a gas or gasses as described above. Such an embodiment is termed a “bubble chamber”. 
       FIG. 1  is a perspective view of an embodiment cylindrical trap primer  100  with optional attached cylindrical outlet distributor  200 . An inlet  126  is provided for attachment to the building water supply pipe (not shown in  FIG. 1 ). The inlet is attached to the upper body  120 , which is reversibly attached to the lower body  102 . Vent holes  118  are arrayed about the lower body neck  109 . An optional cleaning lever  170  which extends through a vent hole is visible in  FIG. 1 . An outlet  116  is attached to the bottom of the neck  109 . An optional outlet distributor  200  is attached to the outlet  116 . A multiplicity of trap supply outlets  209  are used to connect pipes to supply water to a multiplicity of traps (not show in  FIG. 1 ). 
       FIG. 2  is a cross-sectional view of the embodiment trap primer of  FIG. 1  taken at line  2 - 2 . Visible in  FIG. 2 . is the cylindrical upper body inlet  126  with external screw connector  129  for connection to a water supply pipe (not shown in  FIG. 2 ) and an inlet bore  130  for the passage of water into the trap primer. A circular disk-like filter  142  rests on the circular bore shoulder  131  on the inlet bore  130  and is held in place by a filter retainer  140 . A disk-like anti-oscillation valve disc  144  with a valve disc center orifice  145  rests on an inlet shoulder  127 . The combination of inlet bore  130 , inlet bore shoulder  131 , filter screen  142 , and anti-oscillation valve disc  144  is referred to as an anti-oscillation valve  143 . 
     The inlet  126  is attached to the cylindrical upper body  120 . The inlet bore  130  leads to the upper body bore  128 . The Upper body bore  128  penetrates the center of the circular flat upper chamber ceiling  122 . Flow of water into the upper body bore  128  is controlled by the check valve bore  145 . The upper body bore  128  leads to a cylindrical upper chamber  132 . There is a circumferential upper body shoulder  134  which runs around the upper chamber  132 . A circular disk-like flexible diaphragm  146  is located below the upper body shoulder  134 . An inlet check valve  136  is formed when the upper edges of the diaphragm  146  are pressed against the upper body shoulder  134 . A lower chamber  104  is located below the diaphragm  146 . 
     The upper body  120  is reversibly connected to the lower body  102  by screw threads  125  and  103 , respectively. A first embodiment RGE made of closed-cell polymeric medium termed a foam ring  110  rests in the lower chamber  104 . A center hole  115  extends through the center of the foam ring  110 . The valve stem  150  protrudes through the center hole  115 . A multiplicity of foam ring holes  112  penetrate the foam ring  110 . The circular lower chamber rim  106  is located at the top of the lower body  102 . A multiplicity of holes  108  are arrayed below the lower chamber rim  106 . Additional details on the lower chamber rim are found in  FIG. 9 . A valve stem  150  extends through the lower chamber  104  and is attached to the lower body  102 . A valve stem bore  156  extends through the valve stem with the valve stem orifice  158  at the upper end of the bore and valve stem port  160  at the lower end of the bore. The diaphragm  146  reversibly blocks the valve stem orifice  158  forming the trap primer outlet valve  162 . 
     A lower body neck  109  is attached to the bottom of the lower body  102 . A multiplicity of vent holes  118  are arrayed about the lower body neck  109 . The vent holes  118  act as vacuum breakers which prevent backflow of water from an outlet distributor or trap pipe and allow observation of the flow of water from the valve stem port  160 . An outlet bore  116  receives water from the valve stem port  160 . Screw threads  117  on the interior of the outlet bore  116  are used for reversible connection with a optional outlet distributor (see  FIG. 3 ) or with a pipe leading to an individual trap.  FIG. 2  shows the optional cleaning lever  170  which is attached to the optional cleaning probe  172  which extends through the valve stem bore  156  up to the valve stem orifice  158 . 
       FIG. 3  is a cross-sectional view of the embodiment outlet distributor  200  of  FIG. 1  taken at line  3 - 3 . The distributor inlet  202  receives water from the outlet of the trap primer (not shown in  FIG. 3 ). The flow of water enters the flow divider  204  where the flow is divided into each of a multiplicity of distributor bores (four bores in the embodiment of  FIG. 3 ) and the flow  208  descends into the trap supply outlets  209 . Pipes connected to the outlets lead to the individual traps which are served by the trap primer (not shown in  FIG. 3 ). 
       FIG. 4  is a cross-sectional view of the embodiment trap primer of  FIG. 1  taken at line  2 - 2 .  FIG. 4  shows the start-up of the trap primer. The elements of  FIG. 4  are the same as in  FIG. 2 . The flow of water is indicated by arrows. In start-up, water flows into the inlet bore  130  and through the center orifice  145  of the anti-oscillation valve disc  144 . The anti-oscillation valve  143  under these conditions is termed “closed”. The water passes through the upper body bore  128 , and into the upper chamber  132 . The pressure of the water at line pressure closes the trap primer outlet valve  162  by pressing the diaphragm  146  against the valve stem orifice  158 . Water flows through the now open inlet check valve  136  and enters and fills the lower chamber  104 . The line pressure of the water compresses the gas within the closed cells of the polymeric foam ring  110  thereby compressing and distorting the RGE foam ring itself until the pressure within the closed cells within the foam ring equilibrates with the pressure in the water supply line. 
       FIG. 5  is a cross-sectional view of the embodiment trap primer of  FIG. 1  taken at line  2 - 2 .  FIG. 5  shows the trap primer under conditions of stable line pressure. The elements of  FIG. 5  are the same as in  FIG. 2 . Note that the inlet check valve  136  is now closed, as is the trap primer outlet valve  162 . The water pressures in both the upper  132  and the lower  104  chambers are the same. The gas pressure within the closed cells of the RGE polymeric foam medium or foam ring  110  is equilibrated at the same pressure as that of the water in the upper  132  and lower  104  chambers. There is no flow in or out of the trap primer. It should be noted that the trap primer outlet valve opens and closes after a reduction in line pressure and before the increase in pressure to the start-up condition. The trap primer outlet valve will react to a further drop in pressure by opening and closing, even if the original line pressure is not yet restored. 
       FIG. 6  is a cross-sectional view of the embodiment trap primer of  FIG. 1  taken at line  2 - 2 .  FIG. 6  shows the behavior of the trap primer when there is a decrease in the line pressure. The elements of  FIG. 6  are the same as in  FIG. 2 . Flow from the trap primer is activated by a decrease in line water pressure, as accompanies the opening of a faucet or the flushing of a toilet. When the pressure drops, water flows from the upper chamber  132  through the anti-oscillation valve  143  into the inlet bore  130 . Such flow is through the anti-oscillation valve disc orifice  145  and around one edge of a tilted anti-oscillation valve disc  144 . The filter screen  142  prevents the anti-oscillation valve disc  144  from being pushed by the flow of water out of the trap primer into the water supply pipe. Such flow develops because the pressure in the lower chamber, at the previously high level, causes flexing of the diaphragm  146  with simultaneous closing the inlet check valve  134 , thereby maintaining separation of water between the upper and lower chambers by the diaphragm. Simultaneously with the flexing of the diaphragm is the opening of the trap primer outlet valve  162 , allowing the flow of water through the valve stem bore  156  into the outlet bore  116  and ultimately to the trap or traps. The impetus for the flexing of the diaphragm is the gas within the closed pores of the RGE foam ring  110 , which was previously equilibrated at the relatively higher line pressure. The distortion of the ring is relieved as the pressure of the gas within the closed pores reaches the new lower pressure of the supply line. The resumption of the original volume of the foam ring accompanies and is the impetus for the flow of water from the trap primer. When the faucet is closed or water closet replenished the higher pressure in the water supply line is reestablished and the start-up condition show in  FIG. 4  is assumed. 
     It should be noted that the anti-oscillation valve disc allows flow through the anti-oscillation valve disc center orifice only when water is flowing from the water supply line into the trap primer (see  FIG. 4 ). When water flow is reversed, from the trap primer into the water supply line (see  FIG. 6 ), there is flow both through the disc center orifice and, because the valve tilts, around the side of the valve. The delay of water flow from the water supply through the anti-oscillation valve disc orifice has the important effect of delaying the recompression of the RGE foam ring for a fraction of a second. This prevents trap primer oscillation due to water hammer effect. In the absence of an anti-oscillation valve disc the trap primer has a tendency to oscillate from the open to the closed mode. This anti-oscillation valve design allows very low pressure drop sensitivity in the trap primer valve design, observed to be as low as 0.25 psi. 
       FIG. 7  is a cross-sectional view of the embodiment trap primer of  FIG. 1  taken at line  2 - 2  with the cleaning lever and probe.  FIG. 7  shows the action of the cleaning lever and probe. The elements of  FIG. 7  are the same as in  FIG. 2 . Pressing down on the cleaning lever  170  raises the cleaning probe  172  thereby cleaning the valve stem bore  156  and valve stem orifice  158 . Raising the cleaning probe also opens the trap primer outlet valve  162  allowing water to flow through the valve stem orifice  158 , into the valve stem bore  156 , out the valve stem port  160 , and through the outlet bore  116  thereby simulating the function of the trap primer under conditions of reduced line pressure. The flow of water from the valve stem port  160  can be observed through a vent hole  118 , allowing confirmation of the proper function of the trap primer. In embodiments, flow from the trap primer is about 4.2 ounces per minute. Lowering the cleaning probe allows flow in the start-up condition to resume as shown in  FIG. 4 . 
       FIG. 8  is an exploded view of the components of an embodiment trap primer. Visible in  FIG. 8  is a filter retainer  140  which holds the filter screen  142  in place within the upper body inlet  126 . Also visible is the wrench hex  122  on the upper body  120 . Also visible is the upper body o-ring  124 , diaphragm  146 , and the RGE closed-cellular polymer foam ring  110  with center hole  115 . Also visible is the valve stem  150 , valve stem o-ring  152 , and lower body o-ring  154 . Also visible is the lower body  102 , lower body vent holes  118 , and lower body wrench flat  114 . 
       FIG. 9  is a perspective view of the rim of the lower chamber of an embodiment trap primer. Visible in  FIG. 9  is the cylindrical lower chamber  104 , the lower chamber rim  106  at the top of the lower chamber, and the multiple lower chamber rim openings  108  which arrayed about the circumference of the rim  106 . 
       FIG. 10  is a perspective view of the anti-oscillation valve disk  144 . Visible in  FIG. 10  is the center orifice  145 . 
       FIG. 11  is a perspective view of the flexible diaphragm  146 . Visible in  FIG. 11  are a multiplicity of diaphragm centering tabs  147 . In embodiments  6  centering tabs are arrayed about the circumference of the diaphragm. 
       FIG. 12  is cross-sectional view of the embodiment trap primer of  FIG. 1  taken at line  2 - 2  showing the second embodiment RGE polymeric foam medium or foam disk  210  located in the lower chamber  102 . The second embodiment polymeric foam medium or foam disk is shaped like a circular disk with a center hole  215 . Each foam disk of the second embodiment is thinner than the first embodiment foam rings. The valve stem  150  protrudes through the center hole  215  when the foam disks are installed. In embodiments, 4 foam disks are placed in the lower chamber. The second embodiment polymeric medium is identical to the first embodiment in performance and material of manufacture. 
       FIG. 13  is cross-sectional view of the embodiment trap primer of  FIG. 1  taken at line  2 - 2  showing the third embodiment RGE polymeric foam medium or foam particles  310  located in the lower chamber  102 . The foam particles have a generally spherical form. In embodiments the diameter of the particles have a diameter of approximately 0.25 to 0.5 inches. The third embodiment polymeric medium is identical to the first embodiment in performance and material of manufacture. 
       FIG. 14  is a perspective view of the fourth embodiment resilient gas enclosure or bubble chamber  410 . The bubble chamber embodiment has a general donut-shape with a center hole  415 . 
       FIG. 15  is a cross sectional view of the fourth embodiment resilient gas enclosure or bubble chamber  410  taken at line  15 - 15  of  FIG. 14 . Visible in  FIG. 15  is the chamber wall  412  and chamber lumen  414 . The bubble chamber takes the form of a hollow, gas containing sealed structure with impermeable resilient walls made of suitable polymers, such as polyurethane, polyvinyl chloride, polystyrene, polyimide, or silicone and containing in the lumen  414  a gas or gasses such as CO 2 , N 2 , or air. 
       FIG. 16  is a cross-sectional view of the embodiment trap primer of  FIG. 1  taken at line  2 - 2  showing the fourth embodiment resilient gas enclosure or bubble chamber  410  located in the lower chamber  102 . The fourth embodiment medium or bubble chamber is shaped like a circular disk with a center hole  415 . The valve stem  150  protrudes through the center hole  415  when the foam disks are installed. Also visible in  FIG. 16  is the bubble chamber wall  412  and bubble chamber lumen  414 . 
       FIG. 17  is a cross-sectional view of the second embodiment cylindrical upper body  220 . The second embodiment upper body  220  is identical to the first embodiment upper body  120  with the exception of the upper chamber ceiling  222 . In the first embodiment upper body (as in  FIG. 2 ) the upper chamber ceiling  122  is flat. In the second embodiment upper body  220  shown in cross-section in  FIG. 17  the upper chamber ceiling  222  slopes upwardly toward the upper body bore  228 . The second embodiment cylindrical upper chamber  232  therefore has the form of a cylinder topped by a cone with straight sides. The second embodiment upper body chamber is more sensitive to fluctuations in water pressure than the first embodiment upper body chamber. The second embodiment is particularly suitable for use in installations with relatively low water pressure changes or drops. 
     The polymeric foam medium in all RGE embodiments except fourth embodiments is manufactured of a closed-cell polymer foam. Such materials comprise independent, non-communicating cells of a resilient polymeric material, such as a polyurethane, polyvinyl chloride, polystyrene, polyimide, or silicone. Cells in the foam are formed during manufacturing using blowing agents, such as CO 2 , N 2 , or air. A suitable closed-cell polymer foam is polyurethane with closed cells containing CO 2  gas. 
     The wall material of fourth embodiments RGE is manufactured of polymers such as polyurethane, polyvinyl chloride, polystyrene, polyimide, or silicone. The gas or gasses of the fourth embodiment RGEs such as CO 2 , N 2 , or air. 
     While the RGE of all embodiments may be thought of as a sealed chamber of gas or gasses, it should be noted that it can float freely and, unlike pistons, functions while producing little or no friction. No O-rings or other sealing devices are required. The polymeric foam medium responds and the bubble chamber responds very quickly to any positive or negative changes in inlet pressure. The trap primer has been shown to respond to a pressure drop of less than 0.25 psi. 
     In embodiments, both the anti-oscillation valve disc and the flexible diaphragm are manufactured of any suitable relatively light, rigid, strong water-resistant material such as ethylene propylene diene monomer (M-class) rubber, a synthetic rubber also called EPDM rubber. 
     Solid parts of embodiments trap primers are manufactured of any suitable strong, corrosion-resistant material, such as steel, stainless steel, brass, bronze, copper alloys and plastics. In embodiments the valve stem is made of brass. 
     While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope. The applicant or applicants have attempted to disclose all the embodiments of the invention that could be reasonably foreseen. There may be unforeseeable insubstantial modifications that remain as equivalents.

Technology Classification (CPC): 4