Roll seal control valve

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.

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.

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.