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Publication numberUS3738775 A
Publication typeGrant
Publication dateJun 12, 1973
Filing dateOct 7, 1971
Priority dateOct 7, 1971
Publication numberUS 3738775 A, US 3738775A, US-A-3738775, US3738775 A, US3738775A
InventorsStrickland A
Original AssigneeUs Navy
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Constant pressure liquid supply system
US 3738775 A
Abstract
A constant pressure liquid supply system including a tank having an inlet; a pump which has an inlet for receiving fluid and an outlet which is connected to the tank inlet; switch means connected to the pump for turning the pump on and off; and means responsive to fluid pressure within the tank and cooperable with the switch means for turning the pump on when the tank fluid pressure falls below a predetermined level and turning the pump off when the tank fluid pressure attains said predetermined level. A bladder for containing liquid may be mounted in the tank and may have an outlet which extends therefrom for discharging the liquid when squeezed down by fluid pressure within the tank.
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Description  (OCR text may contain errors)

United States Patent 1191 [111 3,738,775 Strickland June 12, 1973 1 CONSTANT PRESSURE LIQUID SUPPLY SYSTEM FOREIGN PATENTS OR APPLICATIONS 1,032,825 6/1966 Great Britain 222/95 [75] Inventor: Alvah T. Strickland, Kailua, Hawaii [73] Assignee: The United States of America as Primary Examiner-C HUS?" represented by the Secretary of the Assismnt Ee Smlth Navy, Washington, DC Attorney-Richard S. Sciascia and Erwin F. Johnston 22 'l d: 0 t. 7 1971 1 e c 57 ABSTRACT [211 App! l87484 A constant pressure liquid supply System including a tank having an inlet; a pump which has an inlet for re- [52] US. Cl 417/38, 222/95, 222/105 ceiving fluid and an outlet which is connected to the [51] Int. Cl. F041) 49/08, B65d 35/28 tank inlet; Switch means connected to the pump for [58] Field of Search 417/38; 222/92, 95, turning the pump on and off; and means responsive to 222/96, 105, 106, 107, 206, 207, 209 fluid pressure within the tank and cooperable with the Switch means for turning the pump on when the tank [56] References Cited fluid pressure falls below a predetermined level and UNITED STATES PATENTS turning the pump off when the tank fluid pressure at- 2 775 205 12,1966 Gunther 417/38 tains said predetermined level. A bladder for contain- 33I8Z47 5/1967 417/38 ing liquid may be mounted in the tank and may have an 3:380:468 4/1968 Folden 417 44 X outlet which extends therefrom for discharging the liq- 3,198,l71 8/1965 Westpha] 417/394 X uid when squeezed down by fluid pressure within the 3,067,810 12/1962 Moz'ic 222/105 .X tank. 1 2,564,163 8/1951 Leperre 222/95 x 2,676,605 4/1954 Meredew 222/95 x 6 Chums, 2 Drawing Flgures 10 24 ,5 6% 4fl 20 15 z? 1-1 Marv/nu Q Mala/T '11::"1 1 '5 PUMP FILTER :1 C 66 s SEA Wgra arrow SWITCH a? 5,0

I 77mg 4140/0 F7351. I 3 [An/0R4 zM E) .14- h STATEMENT OF GOVERNMENT INTEREST The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION In U. S. Pat. No. 3,434,443 entitled Underwater Buoyancy Transport Vehicle to Estabrook there is disclosed a diver operated underwater vehicle which includes a hollow sphere for changing the buoyancy thereof. It has been found that the decomposition products of liquid hydrazine are an excellent medium for deballasting this sphere. This hydrazine or similar medium, is under pressure in a supply tank, and must be available for the beckoning call of the diver. It is desirable that the supply tank remain at a constant pressure until all of the hydrazine is expelled therefrom, and that the tank enable safe loading of the hydrazine and use thereof. Prior art methods of pressurizing underwater fuel tanks involved bottled gas pressurization systems, or the use of elastomers or springs to squeeze the fuel container. Bottled compressed gas loses its efficiency with depth and requires another refueling step before operation of the vehicle. Springs and elastomers result in a pressure drop in the tank as the fuel is expelled therefrom. In some instances a large fraction of the fuel remains in the tank when the tank pressure has dropped to the lowest acceptable level. In regard to the supply tank itself, it is necessary that the hydrazine fuel be separatedfrom the pressurizing medium and that the tank be safe during loading, use, and storage. Prior tank systems for hydrazine stored the hydrazine fuel under pressure. These systems require the transfer of fuel under hazardous field conditions and subjected personnel to possible exposure to hydrazine contamination should the fuel tank rupture. Accordingly, there is a need for a safe system which will efficiently provide hydrazine upon demand for deballasting purposes in an underwater vehicle.

SUMMARY OF THE INVENTION The present invention overcomes the aforementioned problems associated with the prior art by providing a unique constant pressurization system and tank which is especially adapted for handling hazardous liquids, such as hydrazine, in an underwater environment. This system may include a tank which has an inlet; a pump which has an inlet for receiving fluid, such as seawater, and an outlet which is connected to the tank inlet; a switch means connected tothe pump for turning the pump on and off; and means responsive to fluid pressure within the tank and cooperable with the switch means for turning the pump on when the tank fluid pressure falls below a predetermined level and for turning the pump off when the tank fluid pressure attains said predetermined level. A bladder may be mounted in the tank and may be capable of containing the liquid. The bladder may have an outlet extending from the tank for discharging the liquid when squeezed down by the fluid pressure within the tank. It should be understood that the liquid supply system is not confined for use to hazardous liquids such as hydrazine, but can be utilized for supplying practically any liquid or even a gas.

STATEMENT OF THE OBJECTS OF INVENTION An object of the present invention is to overcome the aforementioned problems associated with prior art pressure liquid supply systems.

Another object is to provide a constant pressure liquid supply system which can be utilized safely for loading hazardous fuel, using such fuel, or storing such fuel.

A further object is to provide a constant pressure liquid supply system which is capable of expelling substantially all of the fuel from the system under a constant pressure.

Other objects and many of the attendant advantages of this invention will be readily appreciated as it becomes better understood by reference to the description and accompanying drawings which follow.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic block diagram illustration of the constant pressure liquid supply system; and

FIG. 2 is a detailed cross-sectional view of the supply tank for the constant pressure liquid supply system.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing wherein like reference numerals designate like or similar parts throughout the several views there is shown in FIG. 1 an exemplary constant pressure liquid supply system 10 which is capable of supplying under a constant pressure a hazardous liquid, such as hydrazine, for use in underwater operations. The system 10 includes a tank 12 which has an inlet 14. A pump 16 is provided which has an inlet 18 for receiving fluid, such as ambient seawater, and an outlet 20 which is connected to the tank inlet 14. A switch means, such as push button switch 22, is connected by electrical leads 24 to the pump 16 for turning the pump on and off. Means, such as an accumulator 26, responsive to fluid pressure within the tank 12 and cooperable with the switch 22, is provided for turning the pump 16 on when the tank fluid pressure falls below a predetermined level and turning the pump off when the tank fluid pressure attains the predetermined level. This level will depend upon the needs of the follow on system which demands the fluid supply. When the system 10 is utilized in a seawater environment it is desirable to provide a filter 28 at the inlet 18 of the pump so as to prevent the'intake of foreign material which may damage the system.

The accumulator 26 may include a piston 30 and rod 32 which are disposed within a piston cylinder 34. One end of the piston cylinder 34 may have an inlet 36 which is connected to the outlet 20 of the pump, and at the other end of the cylinder 34 the piston rod 32' may extend therefrom opposite the pushbutton of the switch 22 for turning the pump on and off. A spring 38 may be disposed between the bottom of the piston 30 and the end of the cylinder for biasing the piston toward the cylinder inlet 36. In the arrangement shown the switch 22 is a normally on switch so that when pressure within the volume 40 of the accumulator attains a predetermined level the piston rod 32 engages the push button of the switch 22 and causes the switch to turn the pump 16 off. It should be noted that when this condition occurs the accumulator 26 has stored a supply of fluid within the chamber40 which will supply fluid to the tank 12 under spring pressure 38 until such time that the piston rod 32 backs off sufficiently from the push button of switch 22 to turn on the pump 16. Accordingly, the accumulator 26 serves a double function as an accumulator as well as a means for actuating the system on and off to maintain a constant pressure. The level of actuation is determined by the strength of the spring 38 and the range of fluid pressure between off and on conditions of the pump 16 is determined by the amount of movement of the piston rod 32 before the push-button reactivates the switch 22. In order to prevent loss of fluid pressure from the tank 12 during the period when the pump 16 is in an off condition, a check valve 42 may be located between the outlet 20 of the pump and the inlet 14 of the tank as well as between the outlet 20 of the pump and the inlet 36 of the accumulator.

As illustrated in FIG. 2, a bladder 44 is mounted in the tank 12, and is capable of containing liquid, such as hydrazine. The bladder 44 has an outlet 46 which extends from the tank 12 for discharging the liquid when squeezed down by fluid pressure within the tank. The tank 12, which may be generally cylindrical, may have an annular retainer plate 48 which seals the end of the tank by an O-ring 50, and is removable therefrom when a retainer ring 52 is removed. The retainer ring 52 may be locked in place by a block and bolt combination 54 which is disposed between a space in the ring and is threaded into retainer plate 48.

As illustrated in FIG. 2, the bladder 44 may be generally elongated and may have a rigid end plate 56 and 58 mounted at each end thereof. The end plate 56 may be utilized for connecting the bladder 44 to the retainer plate 48 by bolts 60. In this manner, the bladder 44 is easily removed from the tank 12 upon removal of the retainer plate 48.

A quick disconnect fitting 62, which provides the bladder outlet 46, may be connected to the end plate 56 and may extend through the tanks retainer plate 48 for connection to the liquid consuming system (not shown). The end plate 58 may include bolts 64 which are capable of resting on the bottom of the tank 12 when the tank is uprighted so as to relieve the weight of the bladder and its end plates from the bladder walls when in such position.

In order to facilitate loading of the bladder 44 with liquid fuel, the tank 12 is provided with a vent hole 66 and a removable plug 68 disposed therein. When the bladder 44 is to be filled with liquid, the plug 68 is removed and the pump 16 is turned on to pump fluid, such as water, into the tank 12. When all air has been vented from the tank the pump 16 is turned off and the plug 68 is inserted. The pump 16 is then turned on again and fluid pressure is applied within the tank 12 until the bladder 44 is squeezed down to a minimum volume. The bladder is now readied for receiving a hazardous liquid fuel, such as hydrazine. A hydrazine supply hose may be connected to the quick disconnect62, after which the vent plug 68 may be removed to relieve fluid pressure within the tank 12. Pressure at the quick disconnect opening 46 can then easily completely fill the bladder 44 with the hazardous hydrazine. After the bladder 44 is completely filled the vent plug 68 is inserted so as to ready the system for operation.

In the operation of the system the pump 16, when on, pumps fluid, such as seawater, into the tank 12 and applies a pressure to the bladder 44 which contains liquid fuel, such as hydrazine. The accumulator 26 sees the pressure of the pump and when this pressure has reached a predetermined level the piston rod 32 of the accumulator engages the push button of switch 22 to turn the pump 16 off. The accumulator 26 accumulates a certain amount of seawater to supply operating pressure to the tank 12. When this pressure is lowered sufficiently the piston rod 32 backs off of the push button of the switch 22 to again turn on the pump 16. The pump 16 then operates until the desired fluid pressure is again obtained within the tank 12. In this manner, a substantially constant fluid or seawater pressure is applied to the bladder 44 so that the liquid fuel within the bladder 44 is likewise supplied under a constant pressure through the opening 46.

It is now readily apparent that the present invention provides a unique combination of constant pressurization means as well as a tank for supplying hazardous liquid, such as hydrazine. The present invention has been especially useful in supplying hydrazine fuel for deballasting a buoyancy sphere within the underwater buoyancy transport vehicle described hereinabove.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

I claim:

1. A constant pressure liquid supply system comprismg:

a tank having an inlet;

a pumphaving an inlet for receiving fluid and an outlet which is connected to the tank inlet;

switch means connected to the pump for turning the pump on and off;

means responsive to fluid pressure within the tank and cooperable with the switch means for turning the pump on when the tank fluid pressure falls below a predetermined level and turning the pump off when the tank fluid pressure attains said predetermined level;

a bladder mounted in the tank and capable of containing liquid;

said bladder having an outlet extending from the tank for discharging the liquid when squeezed down by fluid pressure within the tank;

said tank having a retainer plate which seals the tank and is removable therefrom;

said bladder being elongated and having a rigid end plate mounted at each end thereof; and each of the bladder end plate being mounted to the retainer plate.

2. A system as claimed in claim 1 including:

said tank having a fluid vent hole and a removable plug disposed therein.

3. A system as claimed in claim 2 including:

a quick disconnect fitting mounted to said one of the bladder end plates serving as the bladder outlet, and extending through the tanks retainer plate.

4. A system as claimed in claim 3 including:

means mounted to the other bladder end plate for engaging an inside wall of the tank and relieving the weight of the bladder and other end plate when such weights are directed toward said wall.

5. A system as claimed in claim 4 including:

the fluid pressure responsive means being an accumulator which includes a spring biased piston and rod within a cylinder;

6 the outlet of the pump also being connected to the turning the pump on and off.

accumulator for Pp y P agamst Said P 6. A system as claimed in claim 5 including: a check valve connected between the um and the said switch means being a push button switch; and p p said rod extending from the cylinder and being en 5 tank, and the P p and the accumulatorgageable with the push button of the switch for

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2564163 *Jun 11, 1946Aug 14, 1951Lucien Leperre Jean EmileReceptacle with elastic bag insert and system for filling and emptying the same
US2676605 *Nov 7, 1951Apr 27, 1954Charles Meredew GeorgeHydraulic accumulator and like pressure storage vessel
US2775205 *Jan 24, 1952Dec 25, 1956Arnoldo GuntherDevice for automatically refilling tanks
US3067810 *Mar 21, 1960Dec 11, 1962Thompson Ramo Wooldridge IncBladder fuel tank
US3198171 *Jun 30, 1964Aug 3, 1965Westphal James AArtificial habitat and method for the growth and study of deep sea marine organisms
US3318247 *Mar 12, 1965May 9, 1967Yost Clyde EAutomatic pump control
US3380468 *Jun 18, 1964Apr 30, 1968Ke Marc Res DivFluid infusion apparatus
GB1032825A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4073159 *Jul 23, 1976Feb 14, 1978Trippi Anthony CBypass dispenser unit for automatic ice maker
US4212591 *Aug 10, 1978Jul 15, 1980Binks Manufacturing CompanyPressure control for pumps
US4278403 *Sep 6, 1979Jul 14, 1981Shafer Jon LControl for hydraulic accumulator system
US4388044 *Aug 1, 1980Jun 14, 1983Paul WilkinsonWater storage tank
US4497754 *Mar 5, 1981Feb 5, 1985Societa' Italiana Lenti S.I.L.-S.R.L.Molding, heat treatment
US4545504 *Jan 31, 1983Oct 8, 1985Monsanto CompanyHot melt adhesive delivery system
US4659291 *Aug 7, 1984Apr 21, 1987Valdes Osvaldo JHydroelectric switch for controlling electric motor driven pump
US4957220 *Dec 6, 1988Sep 18, 1990Du Benjamin RVending machine last drink sensor and dispensing apparatus
US5645540 *Oct 11, 1994Jul 8, 1997Stryker CorporationMedical apparatus for vacuum draining a surgical wound
US5830198 *Apr 25, 1997Nov 3, 1998Stryker CorporationApparatus for suction draining of liquids from a surgical wound
US6062427 *Aug 27, 1998May 16, 2000Du Investments L.L.C.Beer keg and pre-mixed beverage tank change-over device
US6099264 *Aug 27, 1998Aug 8, 2000Itt Manufacturing Enterprises, Inc.Pump controller
US6305574 *Oct 1, 1999Oct 23, 2001Dow Corning S.A.Dispensing device
US20130105004 *Oct 25, 2012May 2, 2013Graco Minnesota Inc.Hot melt dispensing system with heated accumulator
WO1982000499A1 *Jul 30, 1981Feb 18, 1982Wilkinson PImproved water storage tank
Classifications
U.S. Classification417/38, 222/105, 222/95
International ClassificationB65D88/00, B65D88/62, F15B1/00, F04B43/00, F04B49/02, F15B1/033, F04B43/10
Cooperative ClassificationF04B49/022, F15B1/033, B65D88/62, F04B43/10
European ClassificationF04B43/10, B65D88/62, F15B1/033, F04B49/02C