US1826089A - Pressure control for automatic pumps - Google Patents

Description

Oct. 6, 1931. 1 PERSONS 1,826,089

PRESSURE CONTROL FOR AUTOMATIC PUMPS Filed Aug. 5 192 [72 0972 Z37." Lawrence M P62150723.

4, LAW-1M gig??? Patented Oct. 6, 1931 UNITED.

PATENT OFF-ICE LAWRENCE M. PERSONS, OF CHICAGO, ILLINOIS, A SSIG-NOB TO COOK ELECTRIC COM- PANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS PRESSURE CONTROL FOR AUTOMATIC PUMPC Application filed August 5, 1923. Serial No. 127,253.

M invention relates to pumping apparatus for fluid supply systems. An object of my invention is to provide pumping apparatus having an improved type- 5 of control capable of wide application to fluid supply systems for controlling the supply of fluid fed bythe pump.

In fluid supply systems, particularly those 'employed to feed liquid fuel, say, to oil 19 burners used for heating purposes, or the like, the oil is generally pumped from a storage tank, such as may be installed on the outside of the building, to a supply tank located in the building or adjacent to the 5 burner for the purpose of minimizing the amount of oil necessarily retained within the building near the burner, and from which tank the oil flows to the burner. It is obvious that some means of automatic operation is 20 desirablefor the pumping apparatus, so that a constant supply will be available for feeding to the burner from the supply tank. Considerable attention has been given to such I an automatic control because there is a possibility that it will function to pump the entire contents from the storage tank into the I building in the event a leak occurs, or in the eventa siphoning action takes place after the system is stopped. On the other hand, so there is a tendency to minimize the cost of-oil burner installations, with a consequent tendency to eliminate control apparatus if pos= the switch; and

sible.

One of the objects of my invention is to provide an improved simple and inexpensive form ofcontrohwhich isapractical and may be associated with any type of pump in a fluid supply system, and which embodies all the elements of safety, as well as protects against a siphonic action. of the .fluid when the pump is stopped. Besides afiording greater safety and protection, the control eliminates/ unnecessary piping such 'as an overflow from the pump and may be embodied in a tank located anywhere in the system. While it is desirable to associate the pump with the tank, obviously the pump 7 and tank may be iprovided separately and each located at di erent points in theisys- 50 tem. v

on line 4-4 0 Fig A more specific object of the invention is to provide means for starting and stopping the pump, which means is controlled by the volume or pressure of fluid in the tank, and,

to associate therewith, an air vent operated or by the pressure element to vent air into the tank, thereby breaking any siphonic action which the fluid may have when flowing therefrominto the delivery pipe. .In order to apprise those skilled in the art how to construct and practice my invention, I shall now describe a preferred embodiment thereof in conection with the accompanying drawings forming a part hereof.

,In the drawings: -Fi ure 1 is a dia aromatic view of a fluid supp y system emp oying an improved control embodying my invention;

' Fig. 2 is a detail view of one form of electric switch which may be employed: there- .with- I 3 is a'detail view showing one side of Fig. 4 is a to plan viewofthe switch taken 3 to illustrate the manner in which both sides-of the switch maybe connected in series with each other and in themoin practicallyany type of fluid supplysystemn Where safe, economical and automatic operation is desirable.

In the apparatus shown in the drawings, oil or liquid in the tank 5, or other et 21 may be may be located in any suitable manner in the system. It may comprise a gear pump driven by the motor of an oil distributor or blower commonly employed in oil burner apparatus.

Pump 7 and receptacle 8 are connected by means of a small tube 11, by which the oil enters receptacle 8 after having been drawn from storage'tank 5 by the pump. Ifind it desirable to seal the receptacle against the normal admission of air by suitably attaching its upper open end to the base 12 of pump 7. A suitable motor 14 is furnished to drive the pump. The lower end of the receptacle may be closed. A pressure actuated element 15 is sealed to this lower end, but in communeeating relation with the interior of the receptacle so as to be responsive to and governed by the liquid head therein. Element 15 is illustrated in the present disclosure as a bellows adapted to contract and expand as the volume or pressure of the fluid varies. I find it desirable to locate the switching device below the bellows, thereby positioning it out of the interior of the tank and away from the fluid contained therein. Moreover, it may be placed in a. dirt proof housing 16, conveniently attached to the receptacle in order to protect the contacts of the switch against dirt and oil.

The switching device is preferably of a double actingtype to open the motor circuit when the bellows is either expanded or contracted to a predetermined distance. Hence, motor 14 may be stopped'when two conditions obtain, viz when a maximum pressure or v olume of fluid is contained within receptacle 8, and when a minimum pressure or volume of fluid is present. To accomplish this fea-' ture, a double switch isv provided. Both switches 18 and 19 are substantially the" same in construction and are of a quick make and break type so that the motor circuit is instantly made or broken. Describing but one of these switches, preferably the one-designated 19 shown on the righthand side of Fig. 2, a pivotally mounted plate 20- is carried by a bracket 21 suitably secured in. housing 16, the plate having opposed laterally extending lugs 22 loosel lyin in openings 23 in the sides of the bracket. 3 carbon contact 24 may be secured to the end ofthe plate by interposingtherebetween suitable insulation, such as a lining of mica 25 orthe like. Brackormed to extend outwardly to furnish a seat for a pair of contacts 26 and 27, also suitably insulated. These contacts are inserted in the motor circuit by means of screws 28, which pass through bracket 21 and tacts 26 and 27.. This movement is obtained by the provision of a downwardly projecting arm 29, on the base of bellows 15, cooperating with a spring 30. One end of this spring is fixed to bracket 21, while the opposite end is fastened to plate 20 to move the same upwardly when the spring is released by a lateral pin 31 carried by'arm 29. Pin 31 may ride in a slot 32 formed in the side of bracket 21.

Hence, it will be noted that as bellows 15 contracts, which movement might be the result of a normal flow of fluid out of tank 8 throu h pipe 9 to burner 10, the fluid level will descend and the head or pressure on the bellows will be lowered. When bellows 15 has undergone suflicient contraction, the pin 31 allows spring 30 to flip bridging contact 24 across contacts 26 and 27, thereby closing the motor circuit and allowing pump 7 to start operating, whereby to replenish the fluid withdrawn from tank 8. However,

should the flow from the tank be at a greater rate than that which the pump will function to supply fluid to tank 8, the bellows further contracts and moves pin-31 upwardly until it engages a second spring 35 to open the left hand switch 18. The motor circuit will'again' be broken and the pump stopped.

When the fluid flows, in this manner, at a greater rate from tank 8 than that at which the pump will supply it thereto, an abnormal condition has occurred somewhere in the system. Such abnormal condition may be the result of improper functionin of burner 10, or a leak or siphoning action in the line.

In the event of normal operation, the level in tank 8 will rise if the burner is not consuming fluid as fast as it is supplied by pump To maintain the proper amount of fluid in the tank, the bellows is set to expand when a predetermined high pressure exists in the tank. Such expansion will lower pin 31 to again engage spring 30 to o n switch 19. Thus, the proper amount 0 fluid will be maintained in tank 8.

In order to protect the system against siphoning when pump 7 is stopped, I prefer" to admit air into tank 8, hich tends to break the suction in pipe 9 and stop this siphoning. .Admission of air is controlled by a valve 35 at the side of tank 8. Valve 35 is normally spring pressed a inst its seat 36', but is fomd open by t e contraction of the "bellows. Whenthe system is at rest with the liquid level as shown in the draw ings, bellows is expanded and switch 19 is open. The setting 11 of a si' honic action when pump 7 stops w lower e level, close switch 19, and the contracting movement ofbellows-15 will pivotally swing a lever 36 connected to one end of valve 35,'therebyopening the valve to admit air into tank 8.

The rate of contraction of thebellows in ment may be such, of course, as not to open valve during normal contraction of the bellows, by requiring a predetermined swing of lever 36 before it unseats'thevalve' It will be observed, therefore, that ventmg of air with tank 8 is preferably desirable when the pump is stopped as the result of an abnormal condition, namely, a leak in line 9, or a: siphoning of the fluid after pump 7 is stopped. A leak in line 9 immediately drains tank 8 of its liquid so as to open switch 18. Hence the pump is instantly stopped and the valve is unseated.

It will furthermore be evident that the system is designed to deliver oil to the burner under a sli ht pressure which results from the head 0 oil in pipe!) and receptacle 8. Any breaking of or leak in the delivery line will cause this pressure to fall and immediately cut off the s stem from any further pumping of oil. ence, siphoning of oil is prevented when a leak occurs, thereby assuring safety in the control of the ump, in

that, the entire contents of the b supply. tank 5 cannot be emptied into the basement of the building.

' From the foregoing description, it will be observed that a novel form of automatic control, embodying the essential features of safety required particularly in oil burnin apparatus, is disclosed which is simple and inexpensive, and which may be used universally'with any t pe of pump, associated therewith, or provi ed apart from the pump in the system. Moreover, the control s apand circuit breaker mec the pressure of the liquid fuel in said'receptacle for opening the motor circuit when the rises or falls-beyond predetermined um r.

.parently capable of embodiment with pumps s i-pocket. formed in the lower part of said re-v other than the motor driventype.

Other modifications, arrangements and-embodiments of the resent inventionimay be obtained without ep rtingfrom the spirit and scope of the invention, 3

I .claim: .1. A liquid fuel feeding system including the combination of a pump,"anelectric motor.

for driving said ump, a rece 'tacle for receiving the liquid el suplplied y said pump, anism operated by 2. A fluid supplysysmn including the combination of a a receptaclefor receiving the fluid supphed by and pump, and

pressureoperated means including a bellows communicating withthe interior of said receptacle, said bellows being responsive to and governed by the pressure of the'fluid in said receptacle for stopping of said pump when the pressure rises or falls beyond predetermined limits.

3. A liquid fuel feeding system including 4. A liquid fuel feeding system including the combination of a receptacle containing a varying amountof liquid fuel therein, a delivery line leading from said receptacle, and means controlled by the pressure of the liquid fuel in said receptacle for preventing a si-v phoning of liquid fuel from said source of supply to said receptacle.

5. A fluid supply system including the combination of a source of supply, a receptacle adapted to receive fluid therefrom, a deliver .pipe extending from said receptacle, an means res onsive to and governed by a the pressure of uid in said receptacle for preventing a siphoning of the fluid from said source of supply into said receptacle upon tbze occurrence of. a leak in said delivery pipe.

6. A liquid fuel feeding systemincluding the combination of a source of supply, a receptacle, a motor driven pump for supplying liquid fuel to said receptacle'from said source ofsupply, and electric switch mechanism operated by the pressure of the liquid fuel in said rece tac le whereby to close the motor circuit w enthe amount of liquid fuel therein varies between predetermined limits and to open the .circuit when the amount of liquid fuel therein rises above or falls below said predetermined limits.

7.. A fluid supply systeria including the combination of a source of supply, a recep- -taele, a pump for supplyingfluid to said re- ,ceptaclefrom said source of supply, and a variation of'the fluid-in said receptacle for.

controlling said pump.

no a

8.- A fluid supply system including the andelect'rical means operated by said pres-' device for automatically opening the combination of a source of supply, a recepmotor circuit upon' an increase of pressure j to'a maximum and upon a decrease of pressuretoaminimum.

9. A fluid supply system including the combination of a source. of supply, a receptacle, an electric motor, a pump driven thereby for supplying fluid to said receptacle from said source of supply, a contractible and expansible pressure operated element, and electrical circuit breaking means adapted to open the motor circuit upon a predetermined contraction of said element and upon a predetermined expansion of said element.

10. A fluid supply system including the combination of a source of supply, a receptacle, an electric motor. a pump driven thereby for supplying fluid to said rece tacle from said source of supply, a contracti le and expansible-pressure operated element, and two electrical switching devices, one of said switches opening the motor circuit upon a predete rmined contraction of said element, the other of said switches opening the motor circuit upona predetermined expansion of said element. Y

11. A fluid supply system including the combination of a source of supply,- a receptacle, an electric motor, a pump driven thereby for supplying fluid to said receptacle from said source of supply, a pressure responsive device governed by the pressure in said receptacle, and two electrical switchin devices, one of said switches opening and c osing the motor circuit atoperating pressure for normal control of said pump, the other of said switches opening the motor circuit at minimum pressure for safety control when an ab normal condition obtains.

12. A fluid supply system including the combination of a source of supply, an electric motor, a pump driven thereby, a pressure responsive device, and two electrical switching devices operated thereby, one of said switches opening and closing the motor circuit for normal control when normal operating pressure obtains; the other of said switches opening the motor circuit at minimum pressure for safety control when an abnormal condition obtains. I

13. A fluid supply system including the combination of a pump, a receptacle for re-.

ceiving the fluid pumped, a delivery line communicating with said receptacle, means for starting and stopping the pump according to the pressure of the fluid in said receptacle, and anti-siphoning means for preventing a siphonic action of the fluid through said delivery line.

14. A fluid supply system including the combinationof a pump, a pressure operated element for starting and stopping said pump, and an air vent operated upon the stopping of said pump .for preventing a siphonic action of the fluid through the system.

15. A fluid supply system including the combination of a pump, a receptacle for receiving the fluid pumped, a delivery line communicating with said receptacle, means for starting and stopping the pump according to the pressure of the fluid 1n said receptacle,

and an air vent for said receptacle for preventing a siphonic action'of the fluid when the pump is stopped.

16. A fluid supply system including the combination of a pump, a pressure 0 erated element for starting and stopping sai pump, and anti-siphoning means for preventing a siphonic action of the fluid when the pump is stoppped.

17. A fluid supply system including the combination of a pump, a pressure operated element for starting and'stopping said pump, and anti-siphoning means controlled by said pressure element for preventing a siphonic action of the fluid when the pump is stopped.

18. A fluid supply system including the combination of a pump, a receptacle for receiving the fluid pumped, a delivery line leading from said receptacle, provisions controlled by the pressure of the fluid in said receptacle for starting and stopping said pump, and an air vent operated by said pressure controlled provisions to prevent siphoning of the fluid through said delivery line when the pump is stopped.

19. In combination, a fluid pump, a pressure system supplied by said pump, means for stopping said pump when predetermined maximum and mlmmum pressures obtain in said. system, and means operable thereby to vent air into the s stem to prevent a siphonic action of the fluid in the system.

20. In combination, a fluid pump, a pressure system supplied by said pump, means for stopping sai pump when predetermmedmaximum and minimum pressures obtain in said system, and means operable thereby to preventa siphonic act-ion of the fluid through said s stem when minimum pressure is reached.

. 21. A fluid supply s stem including the combination of a motor riven pump, a receptacle for receiving the fluid pump, a contractible and expansible element operably associated with said receptacle, an electric switch controlled by said element to open the motor circuit when the pressure of the fluid in said receptacle reaches a minimum limit, and a valve adapted to be opened to vent air in said receptacle when the motor circuit is opened by said switch.

22. A fluid supply system includingthe combination of a source of supply, a receptacle, means for delivering fluid from said source of supply to said receptacle, and means controlled by the pressure of the fluid in said receptacle for preventing a siphoning of the fluid from said source of supply to said receptacle upon stopping of said fluid delivery means.

In witness whereof, I have hereunto subscribed my name.

' LAWRENCE M. PERSONS.

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