Abstract:
A water system uses a pressure reservoir of an extremely small size. A valve device is placed between a water pump and the pressure reservoir. The valve device has a constant outlet pressure to limit the flow from the pump at high pressures. The pump is turned on and off by a pressure on/off switch. The valve device maintains the pressure to the reservoir at or below the on switch pressure except for a trickle flow. The trickle flow fills the reservoir when there is little or no water usage from the reservoir. The trickle flow is achieved by a notch in the valve surfaces of the valve device or by a projection preventing the surfaces to seal. Each time the valve opens any debris in the notch is washed from the notch thereby keeping the notch free of debris. Back flow of the trickle is prevented with a roll seal valve by restricting the trickle to a flow path and incorporating a check valve in the flow path.

Description:
CROSS REFERENCE TO RELATED APPLICATION: 
     This is a continuation in part of my prior application on this subject matter filed Feb. 1, 1999, Ser. No: 09/243,730 which was a continuation in part of my application filed Jul. 2, 1997, Ser. No. 08/886,905 now U.S. Pat. No. 5,988,984 which was a continuation in part of my application filed Apr. 24, 1995, Ser. No. 08/427,448 (now abandoned) which was a continuation in part of my application filed Aug. 6, 1993, Ser. No. 08/103,340 (now abandoned). Specific reference is made to the above documents. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to liquid pumps and liquid systems and more particularly to a valve and system to prevent a motor driving a liquid pump from cycling, that is quickly and repeatedly turning off and on. Owners and operators of water systems have ordinary skill in the art of this invention. 
     2. Description of the Related Art 
     Many water pumps supply water to a system having irregular, intermediate use. Often these water pumps supply water into a small reservoir such as a pressure tank. Water systems normally have a range of operating pressures. For example, the range of water of pressures is set between 40 and 60 p.s.i.. This pressure range is normally achieved with a pressure switch which cuts off the motor to the pump at 60 p.s.i. and then turns it on at a pressure of 40 p.s.i. If the use is such that the small pressure tank is quickly drained, the motor is switched on, the pump fills the pressure tank quickly, the pump switches off, and then as the tank is quickly drained, the pump switches on again. Most of the wear and damage to the motors and the pumps is caused by the numerous repeated starts and stops of the system. 
     Such a system as described is common on residential water supplies having a separate water supply for every residence, as often occurs in rural areas. Also the problem arises in systems that have irregular irrigation, for example, golf courses where different flow rates are required. Some systems with cycling problems have multiple pump stations which are activated according to the different supplies of water needed. Also the system with cycling problems exists with tall buildings where because of the building height it is necessary to have controls for different levels of the building, and different flow rates. 
     The problem also exists in liquid systems other than water. For example, the ordinary gasoline fuel dispenser at an auto service station has an electric motor driven pump which delivers fuel to a small pressure tank, then to a metering device, and then to the manually controlled nozzle. When the auto tank is nearly full the customer will often reduce the flow to a dribble to “top off” the tank. This will cause the motor to cycle on and off. 
     Constant outlet pressure valves are well known to the art. Such valves are designed to reduce the flow if the outlet pressure is above the optimum range and to completely stop the flow when it exceeds the preset pressure. 
     Before this invention, attempted solutions to alleviate this problem included installing a constant outlet pressure valve with a small bypass around the constant outlet pressure valve. The valve is installed downstream of the pump and upstream of the reservoir and pressure switch. For example, if the normal flow is fifteen gallons per minute, the bypass provides a flow of one gallon per minute. Therefore, when there is a small volume of flow, the liquid will continue to trickle through the bypass and slowly refill the reservoir. When the reservoir is sufficiently full, the pressure switch will shut the motor off. The reservoir will supply the need until the water flow again reaches levels so that the pressure switch closes, starting the pump motor to fill the reservoir. However, these bypasses exhibited certain problems, one of which being the noise caused by the pressure of the liquid flowing through a small opening. Also, the small opening is susceptible to debris cloggage. 
     My previous grandparent and parent applications, referenced above, solved this problem by cutting a notch in one of the seating surfaces on either the valve seat or the valve device. Therefore, when the valve is closed, the trickle flow is through this notch. Experience has shown that this will not be a noisy flow, nor will it clog. Each time the valve opens debris which might collect in the restricted flow device (the notch) is flushed out by the opening of the valve and the flow of liquid across the notched surface. 
     With some installations this may cause another problem. When the down stream (reservoir) pressure reaches the pressure switch turn off level the down stream pressure exceeds the upstream pressure; this causes a back flow through the notch and through the pump. In most installations the back flow through the pump causes the pump to spin backwards. When the motor is energized with the pump spinning backward the shaft between the pump and motor may break. 
     An obvious solution includes placing a check valve between the pump and reservoir. This solution requires additional elements to be added to the systems. 
     SUMMARY OF THE INVENTION 
     1. Progressive Contribution to the Art 
     This invention solves the back flow problems of trickle flow for roll seal control valves by forming a check valve within the control valve. 
     2. Objects of this Invention 
     An object of this invention is to provide a valve device with controlled outlet pressure. 
     Another object is to prevent the cycling of motors on liquid pumps feeding small reservoirs. 
     A further object is to prevent the cycling with a non-clogging trickle flow through a constant outlet pressure valve. 
     A further object is to prevent back flow. 
     Further objects are to achieve the above with devices that are sturdy, compact, durable, lightweight, simple, safe, efficient, versatile, ecologically compatible, energy conserving, and reliable, yet inexpensive and easy to manufacture, install, operate, and maintain. 
     Other objects are to achieve the above with a method that is versatile, ecologically compatible, energy conserving, efficient, inexpensive, and does not require highly skilled people to install, operate, and maintain. 
     The specific nature of the invention, as well as other objects, uses, and advantages thereof, will clearly appear from the following description and from the accompanying drawings, the different views of which are not necessarily scale drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic representation of a liquid system using a valve device according to this invention. 
     FIG. 2 is a sectional view of a roll seal valve modified according to this invention, in the closed position. 
     FIG. 3 is a sectional view of the modified valve of FIG. 2, in the open position. 
     FIG. 4 is section view of the valve of FIG. 2 taken substantially on line  4 — 4  of FIG. 2 
     FIG. 5 is a sectional view of the valve of FIG. 4 taken substantially on line  5 — 5  of FIG.  4 . 
     FIG. 6 is a sectional view of the valve of FIG. 2 taken substantially an line  6 — 6  of FIG.  2 . 
     FIG. 7 is a sectional view similar to FIG. 6 showing a modification. 
     FIG. 8 is a sectional view similar to FIG. 6 showing another modification. 
     FIG. 9 is a sectional view similar to FIG. 6 showing another modification. 
    
    
     CATALOGUE OF ELEMENTS 
     As an aid to correlating the terms of the claims to the exemplary drawing(s), the following catalog of elements and steps is provided: 
       10  pump 
       12  motor 
       14  water supply 
       16  pump pipe 
       18  control pressure line 
       20  valve device 
       22  pressure switch 
       24  reservoir 
       26  distribution 
       28  reservoir pipe 
       30  housing 
       32  inlet 
       34  outlet 
       36  passage way 
       38  valve seat 
       40  valve member 
       42  diaphragm 
       44  cover 
       46  control chamber 
       48  slotted grillwork 
       50  peripheral section 
       52  valve sealing surface 
       54  seat sealing surface 
       56  pilot valve 
       58  notch 
       60  notch 
       62  project vane 
       64  std vane 
       66  projection 
       68  diaphragm side 
       70  downstream edge 
       72  plate 
       74  opening 
       76  door flap 
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An embodiment of the valve device according to this invention is designed to work with motor driven pumps which are non-positive displacement. The valves would also work with a positive displacement pump if the pump were powered by a motor which would reduce its speed via increased back pressure on the pump. Usually the valves are used on pumps having constant velocity and the flow rate of the pumps decrease with increased pressure. The most common of pumps of this type are centrifugal pumps. 
     The valve devices of this invention will always include a valve seat and a valve element that moves relative to the valve seat. Often the valve seat and the valve each have a plane surface, and the surfaces are always parallel in their relationship. In some cases the valve surfaces are conical. Some valves have a toothed surface to cause a zigzag spray pattern from the partially opened valve instead of a flat spray pattern. Sometimes a butterfly or gate valve in combination with a servo motor is used to open and close the valve control. 
     The valve is basically a constant outlet pressure valve. Upon increase of the downstream pressure, the valve opening is reduced to reduce the flow to maintain downstream pressure. Upon reduced pressure the valve opening increases. Normally the flow will be adjusted by having a spring bias the valve element away from the valve seat. Increased down stream pressure will oppose the spring and will force the valve element toward the valve seat. The programming of the valve to close with additional downstream pressure is within the skill of persons skilled in such art. 
     Referring to FIG. 1 there may be seen a schematic representation of a water system according to this invention. 
     Pump  10  connected to motor  12  pumps liquid from a liquid supply, usually a water supply  14 , into pump pipe  16 . With increased pressure in the pump pipe  16 , the pump  10  pumps less water through the pump pipe  16 . Centrifugal pumps have this as an inherent characteristic as do vane pumps with axial flow. Constant displacement pumps would not have this characteristic; however if the power supply from motor  12  were such that increased load by the pump would reduce the motor speed this would have the required result. The required result, as stated before, is the increased pressure upon pump pipe  16  reducing the volume of flow from the pump  10 . 
     The motor  12  could be of various types. The water supply could be of any type. It might be an underground well. It might be a low pressure reservoir with the pump pumping from the reservoir into a distribution system. 
     The outlet of the pipe  16  is connected to valve device  20  that will be described in detail later. The outlet from the valve device is connected to pressure switch  22 , reservoir  24 , and distribution system  26  by reservoir pipe  28 . According to this invention, the reservoir is a pressure reservoir. In an elevated tank the water pressure of the reservoir pipe  28  will vary with the height of water in the reservoir. More commonly, according to the use of this invention, the reservoir would be a pressure tank having a compressed air cap that under normal practice would be separated from the water by a flexible bladder. Increased water in the tank compresses the air and increases the pressure on the pipe  28 . Such tanks are well known and commercially upon the market. 
     The distribution system might be any distribution system such as a single rural residence; or the complete system for a golf course with a club house including showers, kitchens, etc.; or a small village; or subdivision of a city; or the upper floors of a tall building; or for other liquids such as gasoline pumps. 
     The pressure switch  22  for an electric motor  12  would be a simple switch which at a specified low pressure provides electrical power to the motor  12  and at a preset high pressure cuts off the electric power to the motor  12 . Such switches are well known and commercially available on the market. If the motor  12  were an internal combustion engine, the pressure switch  22  might remain the same, but the control for the motor would be required to have an automatic starting control at the low pressure output from the pressure switch  22  and a shut-off control responsive to the high pressure output from the pressure switch  22 . Such motor controls are also well known and commercially available. 
     Referring to FIG. 1 there may be seen a schematic representing a typical basis for this invention. As may be seen the pump  10  driven by a motor  12  pumps water from a water supply  14  to a reservoir  24  through a valve device  20 . As is customary the motor is turned off when a pressure switch senses a high pressure within the reservoir  24  indicating that the reservoir has designed supply of water. 
     After the motor is turned off the water from the reservoir will be used by the distribution system  26 . When the fluid in the reservoir lowers to a desired level the pressure switch  22  will signal motor  12  to start pumping more water from the water supply  14  to the reservoir  24 . 
     Quite often the reservoir will be a pressurized tank. The maximum pressure will be when the water has compressed the air cap in the tank for a sufficient amount of water. When the water level is depleted to the state the air pressure in the reservoir  24  indicates a water requirement the pressure switch will again start the motor  12 . It will also be understood that if the reservoir was an open tank the elevation of the water in the tank would supply the pressures for controlling the pressure switch. 
     Certain elements have not been shown. One such element would normally be a check valve between the pump and the reservoir to prevent a back flow from the reservoir back to the pump. 
     The valve device  20  is to prevent cycling of the motor. When reasonable pressure shows that the reservoir is getting full, control pressure line  18  from the pipe  28  to the pressure valve device  20  will reduce the amount of water flowing through the valve device so that it does not quickly bring the reservoir up to full pressure but delays it. The valve device always provides a trickle of water sufficient to prevent damage to the pump and to the motor. 
     In many installations the motor and pump are within a well, and the pump is directly connected to the motor in the well. The trickle flow will be sufficient to keep the motor cool. The description as set out is the same of that set out in my prior U.S. Pat. No. 5,988,984. 
     According to this improvement the valve device will be a roll seal valve manufactured by the Cla-Val Valve Company, Inc. P.O. Box1325, Newport Beach, Cailf. 92659-0325. The roll seal valve is a pressure control valve which can be operated to close the flow of water when the downstream pressure reaches a preset level in pipe  28 . As manufactured the valve will completely close, so that not even a trickle of water passes to the reservoir. To cause the valve to permit a trickle of water as outlined above a notch may be cut across the sealing surfaces between the valve sealing surface and the seat sealing surface. 
     Referring more particular to FIG. 2 there may be seen a sectional view of roll seal valve  20  as modified for this purpose. The roll seal valve housing  30  has an inlet  32 , an outlet  34 , and a passage way  36  for the water to flow from the inlet  32  to the outlet  34 . FIG. 2 shows the valve fully closed. 
     FIG. 3 shows the valve in an open position and therefore it may be seen that the water may flow from the inlet to the outlet. The passage way  36  is shown closed in FIG. 2 but is open in FIG.  3 . The passage way is surrounded by valve seat  38 . Valve member  40  includes a diaphragm  42  within the housing  30 . The diaphragm may be displaced toward and away from the valve seat  38  to control the flow through the valve. The housing includes a rigid cover  44 . The cover  44  is between the outlet  34  and the passage way  36 . 
     Control chamber  36  is formed between cover  44  and the diaphragm  42 . The cover is attached to the housing by slotted grillwork  48 . The diaphragm includes an outer peripheral section  50  secured to the cover  44  and aligned with the valve seat  38 . The valve closing area has valve sealing surface  52  which is shown in FIG. 2 to be in contact with seat sealing surface  54 . The valve closure section of the diaphragm is displaced with respect to the valve seat for controlling the flow through the valve seat. The valve sealing surface is contacting the seat sealing surface when the valve member is fully closed. 
     The slotted grillwork includes vanes  64  which connect the housing  30  to the cover  44  and to the valve seat  38 . The vanes are aligned with the flow of water from the inlet  32  to the outlet  34 . As the valve opens the diaphragm  42  rolls up along the vanes  46 . As the valve closes the diaphragm rolls down along the vanes  64 . 
     The description to this point of the roll seal valve  20  is a product which is presently on the market. 
     A liquid passage way across the valve sealing surface  52  and the seat sealing surface  54  provides the trickle flow. Notch  58  is one example of the liquid passage way. 
     It will be understood that the diaphragm is a single unit of elastomeric material. As shown in FIG. 6 the notch  58  may be cut across the seat sealing surface  54 . As shown in FIG. 7 the notch  60  may be cut across the valve sealing surface  52 . 
     Another variation is seen in FIG. 8 where no notches but one vane  62  would project inward further than any of the other vanes  64  rather than the uniform vanes as produced by the Roll Valve Co. 
     Also, as seen in FIG. 9, the flow could be provided by a projection  66  on the valve sealing surface. 
     Referring to FIG. 4 there may be seen a notch  52  or  54  across the seat sealing surface. This notch is between adjacent vanes  64 . The vanes each have a diaphragm edge  68  and a downstream edge  70 . 
     Between the cover  44  and the inlet  32  below the cover  44  the vanes do not extend to the housing  30 . The down stream edges  70  of the vanes are parallel to the axis (not illustrated) of the valve  20 . 
     On the two vanes which straddle the notch  54  a plate  72  is attached over the vanes at the downstream edge  70 . The plate  72  prevents any liquid from passing through the valve  54  from the inlet side  32  to the outlet  34  except for an opening  74  in the plate  72 . This opening  74  allows a trickle flow which flows through the notch  54  to also pass through the opening  74  and into the downstream side. 
     In the situation where the downstream pressure at pipe  28  was higher than the upstream pressure at  16 , a check valve in the form of a flap  76  would prevent this backflow. Therefore, by sealing off the outlet from the vanes it is possible to prevent backflow using a simple check valve within the control valve itself. 
     Those with skill in the ordinary art will understand that although the plate  72  is shown for only one space between vanes, if a liquid passage way extended for a greater length than the distance between adjacent vanes two of the areas could be provided with a sealing plate or with a hole through the plate with the check valve closing the hole to prevent the reverse flow. 
     The embodiment shown and described above is only exemplary. I do not claim to have invented all the parts, elements or steps described. Various modifications can be made in the construction, material, arrangement, and operation, and still be within the scope of my invention. 
     The restrictive description and drawings of the specific examples above do not point out what an infringement of this patent would be, but are to point out the advantages and the progressive contribution to the liquid pump arts and to enable one skilled in the art to make and use the invention. The limits of the invention and the bounds of the patent protection are measured by and defined in the following claims.