US2021850A - Liquid dispensing apparatus - Google Patents

Description

Filed April 8, 1955 2 Sheets-Sheet 1 INVENTOR.

BY 7m ATTORNEYS.

Nov. 19, 1935. N. A. cARLsoN LIQUID DISPENSING APPARATUS Filed April 8, 1935 2 Sheets-Sheet 2 I INVENTOR.

ATTORNEYS.

Patented Nov. 19, 1935 2 PATENT OFFIQE 2,021,850 LIQUID DISPENSING APPARATUS Nelson A. Carlson, Erie, Pa., assignor to Erie Meter Systems, Inc., Erie, Pa... a corporation of Pennsylvania Application April 8, 1933, Serial No. 665,097

10 Claims. (Cl. 221-95) In dispensing some liquids, such as gasoline, diffioulty is experienced by the building up of pressure in the dispensing conduit due to temperature changes. The present invention is designed to provide'for expansion without undue pressure. In carrying out the invention, particularly where a metering system is used provision is made for bringing the liquid content of the system to a uniform condition with relation to the expansion means with each operation of the dispensing apparatus, so that the capacity of the expansion means may be maintained and also the accuracy of the metering system assured. Features and details of the invention will appear from the specification and claims.

A preferred embodiment of the invention is illustrated in the accompanying drawings as follows:-

Fig. 1 shows a view of a gasoline dispensing stand, partly in section, containing the apparatus of the invention. v

Fig. 2 a view of the upper part of a dispensing stand showing a modification.

Fig. 3 a sectional view of a part of the dispensing conduit of Fig. 2.

' Fig. 4 a plan view of the expansion chamber.

Fig. 5 a sectional View of the expansion chamber.

Fig. 6 a sectional view of a valve in the expansion conduit of the structure shown in Fig. 2.

- Fig. 7 a view of a stand with .a further modification.

Fig. 8 a sectional view of the valve arranged in the expansion conduit.

1 marks the ordinary stand case, 2 the storage tank usually arranged under-ground, 3 a supply pipe usually leading from the storage tank, this pipe being provided with a non-return valve 4 in the usual manner. A pump 5 draws the gasoline from the tank. The pump is driven by a motor 6 through a belt drive 1. The gasoline as it is led to the pump passes through a strainer chamber 8 and is discharged from the pump through a pipe 9 to the meter Ill. The meter indicates the flow through the usual dial II. The gas passes from the meter In by way of a pipe l2 to a sight tube l3 showing the presence of gasoline in the line and passes from this sight tube by way of a hose M to a nozzle IS, the nozzle being controlled as commonly by a valve l6 at the nozzle.

The nozzle is hung on the usual hook I! which actuates the lever l8 as the nozzle is hung on the hook. A link 59 extends from the lever l8 to an arm 20 extending from the switch controlling 55'' the motor, this lever l8 and arm 20 being so related as to close the switch when the hook is depressed and to open the switch as the nozzle is removed from the hook and the hook moves upwardly. So far as described this is a common gasoline dispensing apparatus.

It will be noted that in this conduit the gasoline filling the system from the non-return valve 4 to the nozzle valve I6 is trapped in the system, or dispensing conduit between each dispensing operation. The gasoline is drawn from the com- 10 paratively cool storage tank and under some conditions remains in the conduit subjected to what may be a'much higher temperature than that of the tank. This higher temperature operating on the gasoline brings about a very definite expansion of the gasoline and puts the system, particularly the joints and valves of the system under considerable pressure, thus tending to cause leakage'and bring about both loss of gasoline and danger. In the construction shown in Fig. 1 a small pipe 2| leads from the suction side of the pump (as shown from the strainer chamber) to an expansion chamber 22. This expansion chamber is formed with a wall 23 and a flexible diaphragm 24. A wall 25 is arranged opposite the 25 wall 23 and these two sides, or walls 23 and 25 have surrounding flanges 26 between which the edges of the diaphragm are secured. The expansion chamber is secured by brackets 21?, the expansion chamber being provided with ears 28 to 30 which the brackets may be conveniently attached.

In the operation of the device with the first suction efiort on the pump whatever liquid is expanded through the pipe 2! to the expansion chamber is immediately withdrawn, the diaphragm 24 gradually closing on the wall 23, the wall 25 being provided with a vent opening 250 to the atmosphere, so that whatever liquid may have expanded into this chamber is thus withdrawn with each dispensing operation and the 40 expansion chamber at the completion of each dispensing operation is empty and free to receive any expansion which may result from the change or" temperature on the line and this is accomplished without any material pressure on the line.

In Fig. 2 the expansion chamber is connected by a pipe 29 to the discharge side of the pump, in fact, to the discharge side of the metering device. A fitting 38 is arranged in the dispensing conduit at the discharge side of the meter and the pipe 29 extends into and through this fitting by way of a plug 3| at the bottom of the fitting. The upper end of the pipe 29 extends into a Venturi restriction 32. A small check valve 33 is arranged below the fitting 30. This is provided with a non-return ball check 34, the seat of the check being provided with a small passage 35.

In the operation of this modification, when the nozzle is removed from the hook and the pump is started pressure is put on the dispensing conduit and this pressure extends back through the pipe 29. The check valve 33 prevents the fiooding of the expansion chamber, the passage 35 being too small .to permit of a sufficient flow to the expansion chamber to seriously disturb its operation. As soon as the nozzle is open and there is a passage of gasoline past the restriction 32 and the end of the 'pipe '29 the ejector effect is such as to reduce the pressure in the pipe 29 and this suction eifort immediately :empties the expansion chamber, the check Valve 33 yielding for this movement. It will be understood that the modification shown in Fig. 2 has the same fittings (not shown) as used in the structure shown in Fig. 1, the only difference being in the features which we have just above described.

Under some conditions it is desirable to place the expansion chamber at a lower level than that shown in Figs. 1 and 2 and materially below the sight tube and if the valves, or joints do not make a complete closure there would be under these conditions a drainage back through the influence of gravity to the expansion chamber.

In the modification shown in Figs. 7 and 8 the expansion chamber is placed at the bottom of the case and means are provided to prevent this back-flow, or drainage to the expansion chamber while at the same time permitting a back-flow of any liquid incident to a built-up pressure in the line. Thus in Fig. "I the diaphragm chamber is similar to that shown in Figs. 4 and 5 and is connected by the pipe 29 to the discharge side of the meter and is provided with the same features as are found in Fig. 2. In addition there is a control valve 36 in the line 29. This has a nonreturn valve 3'! closed against a back-flow to the expansion chamber. It is seated on the end of the fitting and has a stem extending into the fitting. A spring 33 operating between a shoulder 39 on the fitting and a shoulder '40 on the stem normally closes the valve. This valve has a passage '4! through it in which there is a valve seat 42. A valve 43 operates on this seat. This valve is closed by a spring 44 operating against a shoulder 45 in the stem of the valve37.

In operation when there is any suction effort on the line .29 the valve 31 is opened and any liquid due to expansion in the chamber is removed in the same manner as in the structure shown in Fig. 2. Immediately there is a closure of the nozzle valve the check 33 operates to stop a back-flow from pump pressure and the valve 31 also closes. If pressure builds up in the line this pressure will be sufficient to open the valve 43 and allow the expansion into the expansion chamber. Consequently there is with each operation an emptying of the expansion chamber and a free return flow of any gasoline operating under pressure.

Similarly the expansion chamber at the bottom of the case may be connected with the suction side of the pump, as by the pipe 2|, in which case the valve 36 will operate in exactly the same manner as where the connection is at the discharge.

What I claim as new is:-

1. In a liquid dispensing apparatus, the combination of a closed conduit; a pump arranged in the conduit for driving fluid through the conduit; means trapping the liquid within the conduit; an expansion chamber connected with the conduit at the discharge side only of the pump; and means creating suction effort on the expansion chamber with each dispensing operation.

2. In a liquid dispensing apparatus, the combination of a closed conduit; a pump arranged in the conduit for driving fiuid through the conduit; means trapping the liquid within the conduit; an expansion chamber connected with the conduit at the discharge side of the pump; and

means comprising an ejector subjected to the fiow through the conduit putting suction effort on the expansion chamber.

'3. In a liquid dispensing apparatus, the combination of a closed conduit; means driving fluid through the conduit and trapping liquid therein; an expansion chamber connected with the conduit said chamber being arranged below the high point in the conduit and receiving liquid expanded in the conduit; and means preventing gravity flow to the chamber.

4. In a liquid dispensing apparatus, the combination of a closed conduit; means driving fluid through the conduit and trapping liquid therein; an expansion chamber .connected with the conduit, said chamber being arranged below the-high point in the conduit and receiving liquid expanded in the conduit; means preventing gravity flow to the chamber; and means providing a uniform expansion space that is free of liquid in the chamber with each dispensing operation.

5. In a liquid dispensing apparatus, the :combination of a closed conduit; means driving fiuid through the conduit and trapping liquid therein; an expansion chamber connected with the conduit, said chamber being arranged below the high point in the conduit and receiving liquid expanded in the conduit; means preventing gravity flow to the chamber; and means emptying the chamber with each dispensing operation.

6. In a liquid dispensing apparatus, the :combination of a closed conduit; meansdriving fluid through the conduit and trapping liquid therein; an expansion chamber connected with the conduit, said chamber being arranged below the'high point in the conduit and receiving liquid expanded into the conduit; and means preventing gravity flow to the chamber, said means responding tosuction effort, the connection between the chamber and the conduit effecting suction effort on the chamber.

7. In a liquid dispensing apparatus'thepombination of a closed conduit; means driving fluid through the conduit and trapping the liquid therein between dispensing operations; a pressure-free walled enclosure forming anexpansion chamber connected to the conduit, said chamber accommodating the expansion of the trapped liquid; and means providing a 'uniform expansion space that is free of liquid :in the chamber with each dispensing operation.

.8. In a liquid dispensing apparatus, the'combination of a closed conduit; means driving fluid through the conduit and trapping the liquid therein between dispensing operations; a :pressure-free walled-enclosure forming anexpansion chamber connected to said conduit, said chamber accommodating the-expansion of the trapped liquid; and means emptying the expansion chamber with each dispensing operation.

9. In a liquid dispensing apparatus, the combination'of a closed conduit; means driving'fluid 7 through the conduit and trapping the liquid therein between dispensing operations; and a pressure-free walled enclosure forming an expansion chamber connected to said conduit, said chamber being responsive in capacity to provide pressure-free expansion to the trapped liquid under atmospheric temperatures.

10. In a liquid dispensing apparatus, the combination of a closed conduit; means driving fluid 10 through the conduit and trapping the liquid therein between dispensing operations; a collapsible walled enclosure forming an expansion chamber connected to said conduit, said chamber being responsive in capacity to provide pressurefree expansion to the trapped liquid under atmospheric temperatures; and means emptying the expansion chamber with each dispensing operation.

NELSON A. CARLSON.

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