US2276839A

US2276839A - Liquid dispensing apparatus

Info

Publication number: US2276839A
Application number: US356281A
Authority: US
Inventors: Alfred L Grise
Original assignee: Gilbert and Barker Manufacturing Co Inc
Current assignee: Gilbarco Inc
Priority date: 1940-09-11
Filing date: 1940-09-11
Publication date: 1942-03-17
Anticipated expiration: 1959-03-17

Description

March 17, v1942. A. L. GRISE LIQUID DISPENSING APPARATUS Filed Sept. 11, 1940 INVENTOR Alumni. 651.2

7 %n%as Patented Mar. 17, 1942 2,276,839 '2 Home DISPENSING APPARATUS Alfred L. Grise, Springfield, Mass., assignor to Gilbert & Barker Manufacturing Company, West Springfield, Mass., a corporation of Massachusetts Application September ll, 1940, Serial No. 356,281

8 Claims.

This invention relates to liquid dispensing apparatus of the kind used and knownas a gasoline pump. Generally the same kind of apparatus is used also for dispensing fuel oil for Diesel engines, furnace oil, and other similar liquids.

Specifically, this invention is designed as an improvement over the structure disclosed in my copending application filed July'l9, 1940, bearing Serial No. 346.338, and to overcome some of the inconvenient features of that apparatus. In said copending application I disclosed means to shut oiT completely further delivery through the meter and hose line upon an overloading of the air separator. The structure of said application is adapted to permit delivery to continue but only after stopping for a few seconds to vent the excessive amount of air from the air separating chambers. As will be understood from an examination of that apparatus, the dispensing of liquids under the extraordinary circumstances of an excessive leak in the suction lines is carried on intermittently to insure accurate measurement.

The present application discloses means whereby those inconveniences caused by an intermittent delivery are overcome without losing any of the advantages of that apparatus in controlling the flow of liquid so as to avoid putting more work on the air separator than it can do.

There are other advantages over my prior apparatus which I will discuss in disclosing my present new and improved structure.' While this specification will closely parallel that of my aforesaid applica ion. the superiority of the present device will be made apparent by pointing out the advantages while explaining the operation of this apparatus in connection with the appended drawing, in which- Fig. l is a diagrammatic tus; and

Fig. 2 is a cross-sectional view of the control view of the apparaunderground in tank I, vented through pipe 2,

and filled through pipe 3. Pump 4 moves the liquid from the tank through suction pipe 5 to a point above ground near the point of dispensing. The pump discharges into pipe line 6. Meter 1 in this line measures the liquid discharged by the pump through hose 8 and hand-controlled nozzle valve 9. The air separator ID is in the pipe line 6 between the pump and meter. -A

line and ozzle valve 9 at the dispensing point are closed when no liquid is being delivered. Thus, the apparatus is kept filled with liquid between the tank and the hand valve.

The general operation-of this kind of apparatus is first to close-a switch for a motor, not shown. The motor operates the pump constantly. Until the hand valve 9 is opened manually for delivery, the pump merely operates to by-pass liquid through suitable passages between the suction and discharge sides of the pump. An automatic spring-loaded by-pass valve 4' for this purpose is set to stay closed until the desired discharge pressure is built up by the pump, and when that pressure is reached in pipe line 6 the by-pass valve opens, and the pump tends to maintain that pressure and by-pass the liquid to avoid excess pressure. The apparatus is ready for delivery operations about as soon as the pump motor is turned on. There is no appreciable delay.

When delivery begins by opening valve 9, liquid moves through line B and air separator Ill. The air is taken out of the liquid; the latter then passes through meter 1 and accurately measured liquid within permitted tolerances is delivered through valve 9. If the latter is wide open there is little or no by-passing of liquid, through the pump passages. The pump then discharges to its full capacity, and the liquid goes at the maximum rate through the air separator, the meter, and the delivery nozzle. When delivery is made at less than the maximum rate, the pump by-passes the ditference up to its full capacity.

During these delivery operations at the maxidrawn in due to the suction. For a given size leak in this line the maximum quantity of airwill of course be drawn in during the maximum rate of delivery. At this time the maximum load is put on the air separator for that size leak.

'Air separators are used throughout'the trade indifierent sizes, each size designed with the idea of a maximum load capacity for it. If overloaded in any particular apparatus, an air separator becomes ineflicient. It permits more air to be measured with liquid than permitted by accepted tolerances and the whole apparatus-is ineflicient for accurate measuring purposes .within accepted practical limits.

Consider the case of air leaking .in suction line 5. (It joins the liquid pumped into separator H). In this, it rises to thetop of liquid in main check valve 5 at the entrance to the suction chamber ll, goes out with some liquid through goes to the top of this liquid. So far, the structure and operation are of the prior art. In that art the air is commonly vented freely to the atmosphere from the top of a chamber like it.

In my improvement, as illustrated, this air has a passage through pipe l2 from chamber I! to the piston chamber II. From the latter a vent passage l1 leads to the atmosphere. The passage I1 is restricted, say to less than a sixteenth of an inch, and for a particular purpose. Theseparator is arranged so it can feed air, separated from liquid, and pass more air over to chamber it than can be vented through passage I! to the atmosphere. This is preferably arranged to occur as the amount of air approaches the maximum capacity for efficient air separator operation. The pressure in the apparatus on the discharge side of the pump moves the air along the path described. The action under emergency conditions to be explained is for air from the separator to partially vent itself out passage l1 and to accumulate under sumcient pressure in chamber It, to operate its piston I8.

This piston is spring loaded, tending to move upwardly. When up, the connection by arm 29 with ,valve l9 keeps that valve wide open. The valvell! is preferably located in the main pipe line between pump I and the main air separator chamber H. In this position it not only controls the rate of flow from the pump to the air separator, but also the rate of liquid delivery at the dispensing point. This particular location of valve is is one of the features of the present invention. Its advantage will be clear from the following considerations.

When more air is forced in chamber l6 than can get out vent passage II, air pressure results. This moves piston 12' down and tends to move valve I! to a closed position. However, provi'-' slon is here made to permit a diminished delivery of liquid to the air separator. The valve I! as seen in Fig. 2 is so constructed that it cannot completely close oil the pipe passage between the pump-and the air separator. In my preferred form shown, I have drilledtwo holes 22 in the valve disk 22 on each side of valve stem 2| so that when the valve is seated in closed position liquid may flow through the holes 22 and a reduced delivery can be maintained at the nozzle end.

Valve I9, as shown, except for holes 20, is of an ordinary type of construction and needs no detailed description. The raising and lowering of arm 29 fixed to the turning pin 23 (Fig. 1)

' actuates the control arm 24 which will raise and lower the valve disk 22. The particular construction of the valve is unimportant as many other types of valves could be adapted for the purpose. Also it will be readily understoodthat a reduced rate of delivery could be accomplished by providing a stop for the disk 22 or limiting the piston thrust to keep disk 22 partially off its seat. The object is to provide a reduced delivery 'to the air separator whenever the pressure in piston chamber l6 moves disk 22 toward closed position.

In this arrangement of apparatus with the automatic control valve I! placed before the sepaaraeao adapted to move less air to the air separator than in my aforesaid prior construction. Two features of valve IS, the one of merely reducing the rate of flow and the other one in doing this on the inlet side of the air separator, increases the efllciency of the air separator in the system. The operation while delivering air-freed liquid under this arrangement to the meter at the lower rate of delivery is an improved operation. I believe air sucked in through a leak in suction line 5.

The 'by-passing of liquid and air due to the restricted passageway operates to have the pump circulate the mixture around through the pump again. Thus, the pump receives whatever goes through the by-pass line. The amount of mixture sucked from supply line 5 and tank I is only that necessary to displace the amount forced through the restriction in the valve J9. And as described, this is a substantially reduced amount. Therefore, the pump exerts much less suction than it did before valve 1! reduced the flow and the by-pass valve 4' operated to partially short-circuit the pump. Thus, much less air is introduced through the leak-into the system while the reduced delivery rate is maintained.

The obstruction provided by valve l9, being on the inlet side of the air separator instead of the outlet side, as it is in my former construction, the air separator is saved from the reaction in the nature of a water hammer when the obstruction due to valve 19 becomes effective. action goes back to the pump and the pump bypass functions to best take care of such reaction in pressure. If the reaction of the back pressure is applied to the air separator it interferes arator, the operation is particularly useful, It is 7 5 with the air separator functions. Any turbulent condition of the air separator contents will so interfere. My object is to make improved arrangements for clearing the liquid of air in the air separator. I believe that by reducing the rate of flow on the inlet side of the air separator the latter will clear itself faster and, by reducing its overload pressure, permit the full rate of flow to be again established with effective measuring of that flow. My tests definitely indicate the advantages as I have stated them.

In my said prior application, I advised shutting off the motor to permit the air separator to get rid of its overload. In my apparatus now disclosed the separator will generally clear itself automatically without shutting off the motor. This has the advantage of continued uninterrupted properly measured deliveries under most conditions of serious leaks. There is the further advantage in dispensing apparatus of this kind that the meter registering mechanism does not have to be turned back to zero to start the motor asit does when pumping is stopped to clear the air separator. An interlock mechanism is usually provided between the motor switch and the registering mechanism so that the motor cannot be started for measured delivery in liquid dispensing apparatus generally, unless the registering mechanism is set back to zero. This is not a desirable condition when the motor is stopped in the middle of a delivery to clear the air sep- The re-.

arator as indicated in my said application. My

new apparatus avoids the difliculty.

As illustrative of the contemplated operation of the device, an apparatus with valve l9 completely open may have a maximum delivery of about 25 gallons 9. minute at the nozzle outlet. This is the ordinary situation of a fast dispensing appa ratus in which the air separator is not over-- loaded. When being overloaded because of a serious leak in the suction lines, the air separator in my apparatus will increase the air pressure on piston l8 and move valve Hi to its closed position. The restricted passageway in pipe line 6 will then allow a rate of delivery at the nozzle outlet of about gallons per minute. The air separator is of sufficient size to accommodate efficiently this reduction in the flow of air and liquid from the pump 4. Any flow tendency from the constantly operating pump beyond the amount providing a rate Lof about 10 gallons per minute when valve I9 is closed, through the meter and out the nozzle end will open the valve 4 in the by-pass between the suction and discharge sides of the pump 4.

The rate of delivery to the air separator, through the meter and through the nozzle, being thus reduced, the air separator is enabled to clear itself of the excess air pressure that has accumulated in the various chambers. When the pressure is dissipated, the piston l8 will rise to its uppermost position and allow the valve 19 to open to its full limit. The pump is thus allowed to stop its by-passing operation of about fifteen gallons a minute and to function at its best rate considering the amount of air coming into the system. This continues until such time as the pressure again builds up in the separating cham-#, ber sufficiently to again operate valve l9. Consequently, the action under the circumstances of an excessive leak is one of a relatively high-rate of delivery with intermittent periods of delivery at a reduced but sufficient rate of flow for a practical delivery. The apparatus while continuing operation automatically prevents overloading the air separator and insures a full and accurate measurement of liquid.

As in my previous invention, the advantage is preserved of being able to use a smaller size air separator in dispensing apparatus without having the latter condemned by the officials of weights and measures on'account of the possibility of a large air leak. These ofiicials require a high degree of efllciency to guard against all possible leaks, and very large separators have been generally made to satisfy their requirements. Here the invention automatically reduces delivery when air leaks are excessive and this permits the smaller size separator to be used efllciently and prevent false measurement, as did my former structure.

The foregoing disclosure covers apparatus adapted to use a comparatively small air separator with a high rate of liquid delivery. In the emergency of an overload for such separator the apparatus functions safely for liquid measurement at a reduced rate of delivery. The illus trative example given is from twenty-five to ten gallons per minute.

As a further refinement I will disclose the means to prevent the use of the apparatus for measurement if the comparatively small air separator would not protect against false measurement at the reduced rate of flow through it which might happen in a. very special case. Such a case might'arise if the pump were built to maintain a pressure suflicient for delivery through and operation of the meter, regardless of whether the pump worked on air .or liquid or any mixture. Then, as a suction leak admitting air increases in size, a point would be finally reached when only air would be delivered. In such an extreme case there, would be false measurement.

A way to avoid this in my apparatus is to build the pump in a particular way with relation to the meter. In my example of operating with a re duction from twenty-five to ten gallons a minute, the way to build the pump i in this fashion: Provide enough clearances so that it cannot build up suflicient pressure through the meter for delivering either air alone or a mixture of too much air and liquid that will operate the meter. The meter ordinarily operates from the pressure of the liquid pushed through it by the pump. The latter can easily be made to be efficient for liquid and inefficient for air or a mixture with too much air in it. This is done simply byproviding clearances for the pump piston construction that are altogether too much for air and entirely practical where there is sufllcient liquid for the efficient operation of the pump at the desired pump pressure and rates of liquid flow. The principle to use in my apparatus is to build-the pump so it will be efllcient for a measured liquid delivery at the low rate but ineiiiclent'to pass substantially less than that much liquid-together with enough air through the pump to overload the air separator and'send the less rate of liquid to the meter with enough pressure to operate the meter. of course each particular apparatus will need to be calibrated and engineered to get the rates of delivery wanted. But the principles of operation and th way to adapt the apparatus for the desirable results will be clear to the man in this art from what I have said. It will be clear that the air will permit much more slip due to pump piston clearances and any air that is pumped will pass much faster through the air separator when such slipping and venting is not substantially obstructed by a substantial amount of liq- .uid in the apparatus. Thus, the pump may have ought, as a practical matter, to be almost entirely non-existent. The operator, before such a situation is allowed to develop, has previously had full and ample warning that a serious leak was present in the system when the rate of delivery was first automatically restricted. His action should of coursebe torepair the suction lines as soon as possible. He has paid for an apparatus capable of a high rate of delivery. He knows that todisregard the warning of an automatic reduction in rate is -to take the chance of losing an appreciable amount of liquid fuel through such a leak. In idle periods of the apparatus liquid leaks out the same openings where during operation air is sucked in.

In describing my invention thus far the emphasis has been upon its utility with reference to gasoline pumps capable of dispensing liquid at high rates of delivery. It also has important utility when. used with the ordinary gasoline dispensing apparatus which commonly has a maximum capacity of from twelve to fliteen gallons per minute. The size of air separator used in this system has been conveniently fitted within the casing, but my device for a restricted flow has special advantages to warrant its use in this type of apparatus. Not only does it afiord a sharp warning to the operator of the presence of a leak in the suction line, but it also affords the manufacturer a cheaper way to solve the problem of air separation. A smaller and less expensive air separator element can now be used in the apparatus. I f

Heretoiore, it has been necessary to cast the separators especially for the purpose. When the device of my invention is employed in the ordinary apparatus the size of separator needed is small enough to be made from piping and of very simple construction. The expense of making a special cast-ironseparator as a part of the apparatus is large in comparison withthe expense in forming a separator from piping or tubing and using my invention in connection with it. Consequently, my device can be used with great advantage in the ordinary system because of the saving in manufacturing costs, or the saving in space.

Having disclosedmy invention, I claim:

1. In liquid dispensing apparatus, the combina-- tion of a delivery pump havingan automatically controlled by-pass operable to avoid excess pump pressure, an air separator to receive the pump discharge, a meter to receive the discharge from the separator, a valve in the line to control the liquid flow to the meter, automatically operated pneumatic mechanism to actuate said valve, and means including a restricted vent from the air separator to accumulate pneumatic pressure from air tending to vent from the separator, said means acting only when the separator is operating at about the limit of its efliciency, said mechanism being operable to move said valve towards closed position only when air is accumulated by said means in the manner stated for actuating said pneumatic mechanism, said valve being otherwise open.

2. In liquid dispensing apparatus having a pump to discharge through an air separator and meter, means operable, when air leaks in from the suction side of the pump beyond a predetermined rate, to regulate the flow through the meter, said means comprising in combination an air separator having a restricted air vent, an air pressure mechanism operable by accumulat ing air pressure in said separator and a device operable by said mechanism to regulate the flow in said separator, and a device operable by said mechanism to automatically prevent overloading the air separator, said device including a valve and pneumatic means to control said valve by operation of air pressure in the separator, whereby the separator is guarded against being renaavaaao dered inefficient for separating air from liquid flowing through it.

4. In liquid dispensing apparatus having a supply tank and a dispensing valve and a pump, air

separator. and meter elements in the pipe line charged liquid, the" other having a restricted passage to receive the vented mixture and vent the air while returning the liquid to the system, a

' ber having a passage for recovery of liquid therefrom and a vent passage to direct air to the atmosphere, said vent passage having means interposed in said passage to restrict the flow of air to the atmosphere at a lower rate than it can reach the secondary chamber when the main chamber is functioning near its efllcient limit for discharging air-freed liquid, a valve operable by said means upon an increase in the pressure of air tending to escape to the atmosphere, said valve being adapted to prevent delivery of aircharged liquid from the main chamber.

6. The combination of an air separator, a cylinder and piston, means tending to'hold the piston in one position, a passage between saidseparator and cylinder, a vent in the cylinder for air flowing from said separator, said vent being restricted whereby the piston is operated by the pressure of air flowing into the separator and cylinder beyond the rate at which it can be efllciently separated from liquid in the separator, and-a valve automatically operable by said piston to control the operation of said separator.

7.,A dispensing apparatus adapted to pump liquid from storage to dispensing points and to measure the liquid substantiallyireed from air,

including in combination a conduit having therein a pump of the back pressure relief type, an air separator apparatus, a meter, a dispensing valve, all connected by the conduit in the recited order and somewhere in said conduit between said pump and said nozzle a normally open automatically controlled valve adapted for closing movement to control dispensing when the pump is operating and the dispensing valve is open and in the event of an emergency, pneumatic mechanism adapted to actuate the valve in its closing movement in the event that air beyond the air venting capacity of said air separator apparatus is pumped into the latter,.restricted means to vent to the atmosphere air freed from liquid by said separator apparatus, said means being restricted enough in its venting capacity so as to build up air pressure in said apparatus as the latter tends to be loaded beyond its intended separating capacity, and a connection for such air pressure to operate said pneumatic mechanism for its automatic valve actuating purpose.

8. In a liquid dispensing system having a source of liquid supply, a flow line therefrom, and a the pressure control and direction of actuation of such mechanism being dependent on the pressure condition in the air separator created by the pump, that pressure condition created by ex- 6 cessive air leaks acting to move the mechanism in one direction and that pressure condition created in the absence of air leaks acting to move the mechanism in the other direction, all automatically operable under the conditions stated 10 during any dispensing operation.

ALFRED L.- GRISE.