Abstract:
An accumulator for collecting a volume of a liquid, which includes controls to permit the liquid to rise in a container to a preset upper level, at which level a drain valve is opened causing liquid to flow out of the accumulator. The accumulator utilizes two opened bottom pipes, which are connected through check valves to a controller. The controller is sensitive to the pressure at its inlet port. The pipes are interconnected so that when the liquid reaches an upper level, the pressure at the controller is sufficient to open the drain valve, and once the accumulator is almost empty, the drain valve is closed.

Description:
BACKGROUND OF THE INVENTION 
     The field of the invention is plumbing fixtures and the invention relates more particularly to piping a control system for permitting the accumulation of water or other liquids in a box and emptying the accumulated liquid when the box is full. 
     A pressure sensitive controller is shown in U.S. Pat. No. 6,311,718, assigned to the assignee of the present invention. The specification and drawings of this patent are incorporated by reference herein for purposes of background. A waste disposal system is shown in U.S. Pat. No. 6,385,789, which utilizes a vacuum operated discharge valve. The system utilizes an electrically operated control valve and is operated by depressing a flush button. 
     U.S. Pat. No. 6,349,425 also shows a vacuum toilet system. The unit is operated in response to a flush command. The same unit is shown in U.S. Pat. Nos. 6,353,942 and 6,370,709. A vacuum drainage system is shown in U.S. Pat. No. 6,305,403. A buffer box used in a vacuum drainage system is shown in U.S. Pat. No. 6,311,717. 
     BRIEF SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an accumulator box which will empty liquid from the accumulator box when the liquid reaches a predetermined level without the use of any electrical signal. 
     The present invention is for an accumulator for collecting a volume of a liquid, including means for removing the liquid when the liquid reaches a predetermined level in the accumulator. The accumulator has a box for holding a volume of liquid and the box has an outlet port near its bottom for passing liquid out of the box. An inlet opening allows liquid to pass into the box and to be accumulated in the box. A first control pipe is held within the interior of the box and has an open bottom near the bottom of the box and has a closed top. A second control pipe is also held within the interior of the box and has an open bottom spaced further away from the bottom of the box than the open bottom of the first control pipe. A conduit passes from the closed top of the first control pipe to the inlet port of a pressure sensitive controller. The first conduit has a first check valve permitting the flow of gas only in the direction of the first control pipe. A second conduit leads from the closed top of the second control pipe to a point where it joins the first conduit at a location in the first conduit between the first check valve and the inlet port of the pressure sensitive controller. The second conduit has a second check valve therein permitting the flow of gas only in the direction of the pressure sensitive controller. As the level of liquid rises in the box, it initially increases the air pressure within the first control pipe, but the first check valve prevents this increase in pressure from passing to the inlet of the pressure sensitive controller. As the liquid level rises further, it reaches the open bottom of the second control pipe. As the pressure within the second control pipe increases, this increase in pressure is passed to the inlet port of the pressure sensitive controller. When the level of liquid has reached a predetermined distance above the open bottom of the second control pipe, the pressure is sufficient to actuate the pressure sensitive controller, thereby opening a drain valve and emptying the contents of the box. The present invention is also for the process of operating the accumulator. The drain valve is closed when the liquid level drops below the bottom of the first control pipe. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagrammatic view of the accumulator of the present invention. 
     FIG. 2 is a top view thereof. 
     FIG. 3 is a side view thereof. 
     FIG. 4A is a diagrammatic view thereof, showing the liquid level at a lowermost position. 
     FIG. 4B is a diagrammatic view thereof, showing the liquid level increased from that shown in FIG.  4 A. 
     FIG. 4C is a diagrammatic view thereof, showing the liquid level increased to a further height, as compared to that shown in FIG.  4 B. 
     FIG. 4D is a diagrammatic view thereof, showing the liquid level decreasing. 
     FIG. 4E is a diagrammatic view thereof, showing the liquid level at the end of the draining step. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The accumulator of the present invention is shown in diagrammatic view in FIG.  1  and indicated generally by reference character  10 . Accumulator  10  has a box or receptacle  11 , which is typically a stainless steel rectangular box. Box  11  has a bottom  12 , sides  13 , and a top  14 . Box  11  has an outlet drain line  15  affixed over an outlet opening  16  adjacent the bottom  12  of box  11 . The word “adjacent” is intended to include an outlet in bottom  12  itself, as well as along the side, either at the bottom or a short distance from the bottom. Furthermore, the outlet drain line could extend into the interior volume  17  of the accumulator. Thus, the important feature is that the outlet drain line  15  be connected to box  11  such that the imposition of a vacuum in line  15  will cause the liquid contents of box  11  to be largely removed from the interior volume  17 . 
     A pair of control pipes comprising a first control pipe  18  and a second control pipe  19 , are positioned largely within the interior volume  17  of box  11 . First control pipe has an open bottom  20  which is positioned a first distance  21  from the bottom  12  of the box  11 . Control pipe  18  has a first interior space  21  and a closed top  22 . A first conduit  23  is connected in an airtight manner to closed top  22  and permits air or whatever gas the accumulator is positioned within to pass from the first interior space  21  into the first conduit  23 . A first check valve  24  is positioned in first conduit  23  and permits the flow of air in the direction of arrow  25  toward the first interior space  21 . It, of course, prevents the flow of air out of interior space  21 . 
     First conduit  23  continues from first check valve  24  and is connected to the inlet port  26  of a pressure sensitive controller  27 . 
     Pressure sensitive controller  27  may be of the type shown in U.S. Pat. No. 6,311,718, however any other pressure sensitive controller with sufficient sensitivity can be used. The pressure sensitive controller is preferably of the type which may be adjusted to output a signal when the pressure at the inlet port reaches a predetermined level. For instance, the controller  27  can be set so that when the pressure at inlet port  26  reaches two inches of water, a signal is initiated through line  28  to control valve  29 . When control valve  29  is opened, a vacuum is pulled on outlet drain line  15  as long as control valve remains open. The pressure sensitive controller typically is set so that when the pressure at inlet port  26  reaches  0 , the signal is discontinued through line  28  turning off control valve  29 . of course when the term “pressure” is used herein, it is intended to indicate gauge pressure and not absolute pressure. It is also to be understood that the controller  27  could be set so that when the pressure at the inlet port reaches, for instance ¼ of an inch of water, the signal through line  28  is discontinued. 
     When the pressure sensitive control valve indicated above is utilized, it is not necessary that any source of electricity be utilized in the elements shown in FIG. 1, since they are all controlled by air pressure and vacuum. 
     A liquid inlet line  30  provides a source of water or other liquid. This source might be the condensate from a refrigeration system or from some other source which causes the liquid level  31  to increase until the drain signal is received. Top cover  9  has an inlet opening  44  over which a source of liquid, such as sink drain  45  shown in phantom view in FIG. 3, is positioned). 
     The second control pipe  19  has a second interior space  32 , an open bottom  33 , and a closed top  34 . A second conduit  35  is connected to closed top  34  to pass air or other gas from second interior space  32  into second conduit  35 . 
     Second conduit  35  has a second check valve  36  which permits air to flow only in the direction of arrow  37  out of second interior space  32 . Second conduit  35  continues to a connection tee  38 . This connects second conduit  35  to first conduit  23  between first check valve  24  and inlet port  26 . 
     The open bottom  33  of second control pipe  19  is positioned a third distance  39  from bottom  12 . Third distance  39  is greater than first distance  21  for reasons discussed below. Closed top  22  is spaced a second distance  40  from bottom  12  and closed top  36  is separated a fourth distance  41  from bottom  12 . 
     The diagrammatic view of FIG. 1 is shown in top view in FIG.  2 . Control pipes  18  and  19  are shown with their respective closed tops  22  and  34 . An outlet port  42  leads through closed top  22  into first conduit  23 . Similarly, outlet port  43  leads through closed top  34  into second conduit  35 . 
     Turning to FIG. 3, box  11  is shown in side view and control pipes  18  and  19  are shown in phantom view with their bottoms  20  and  33 , respectively, also being indicated in phantom view. Details of the outlet port  43  are shown as are details of the closed top  34 . 
     The operation of the accumulator can be understood best from a description of air pressures at various liquid levels indicated in FIGS. 4A through 4E. Pressure will be indicated in the discussion in units of inches of water, although of course, if other liquids are being accumulated, the units would be inches of whatever liquid is being accumulated. 
     As liquid enters through sink drain  45 , the water level within box  11  rises to that shown in FIG.  4 A and indicated by reference character  46 . Water level  46  is above the bottom  20  of control pipe  18  and, thus, a small amount of pressure builds up in that portion of line  23  which is between first check valve  24  and control pipe  18 , as well as in the control pipe interior space  21 . Because check valve  24  does not permit the flow of gas out of control pipe  18 , the pressure in that portion of line  23  between check valve  24  and inlet port  26  remains at 0 atmospheric pressure. 
     As shown in FIG. 4B, as the water level continues to increase, the pressure in control pipe  18  in the portion of conduit  23  up to check valve  24  also increases to, for instance, four inches, whereas the pressure in line  23  after check valve remains at atmospheric pressure. The water level in FIG. 4B is indicated by reference character  47  and is still below the bottom  33  of control pipe  19 . 
     Turning now to FIG. 4C, the water level  48  has risen above the open bottom  33  of control pipe  19  and causes the pressure in second conduit  35  to increase to two inches, since the air which is being compressed within control pipe  19 , will pass through second check valve  36 . This causes the pressure from first check valve  24  to the inlet  26  of controller  27  and in that portion of conduit  35  between check valve  36  and conduit  23  all to rise to two inches. Assuming that this is the set pressure of controller  27 , a signal is sent through line  28  to open drain valve  29  and cause the water level to drop as indicated in FIG. 4D, first to a position below the bottom  33  of second control pipe  19 . Since the second check valve  36  maintains the pressure of two inches-in conduit  23 , the signal continues to be sent to valve  29  to continue the draining of water out of outlet drain line  15 . Thus, when the water level  49  falls below bottom  33 , there is no effect on the pressure at the inlet  26  of controller  27 . 
     However, when the water level reaches that shown by reference character  50  in FIG. 4E, air can escape, as indicated by arrows  51  into the atmosphere. Since first check valve  24  permits the pressure in line  23  to pass through it to the lower pressure or atmospheric pressure within first control pipe  18 , the controller  27  turns off the signal through line  28 , thereby shutting off control valve  29  and preparing the accumulator for a new collection cycle. 
     Obviously, the length of the control pipes can be adjusted to provide the desired upper and lower levels of liquid within box  11 . It is important that the first distance  21  between the open bottom  20  and bottom  12  is less than the distance  39  between open bottom  33  and bottom  12 . Typically, the second and fourth distances  40  and  41 , respectively, would be the same, although this is not essential. It is also preferred that the third distance  39  be less than half of the second distance  40 , so that sufficient pressure and volume can build up in the second interior space  22  and second conduit  35 , so that there will be sufficient pressure and volume transferred to interior space  21  to empty the interior space and permit air to enter open bottom  20 . 
     For a box having a height of 12 inches, one example of a set of useful distances are as follows: 
     First distance—½ inch 
     Second distance 14 inches 
     Third distance 4 inches 
     Fourth distance 14 inches. 
     A useful control pipe size has been 1½ inch PVC pipe with a cap. Obviously, the dimensions would be dependent upon the size of box  11 . 
     The present embodiments of this invention are thus to be considered in all respects as illustrative and not restrictive; the scope of the invention being indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.