US1935544A - Liquid dispensing pump - Google Patents

Description

Nov, 14, 1933. w. H. DE L'ANCEY 1,935,544

LIQUID DISPENSING PUMP Filed Jan. 14, 1932 2 Sheets-Sheet l INVENTOR. MRREMHZYELAMEY BY IM A TTORNEYS.

Nov. 14, 1933.- f w, H. DE LANCEY 1,935,544

LIQUID DISPENSING PUMP Filed Jan. 14, 1932 2 Sheets-Sheet 2 I INVENTOR. Mkkf/VHDfiZAA/CEV af/am & ATTORNEYS.

Patented Nov. 14, 1933 PATENT OFFICE 1,935,544 noun) DISPENSING PUMP Warren a. De Lanc ey, Springfield, assignor to Gilbert & Barker Manufacturing Company, West Springfield, Mass, a corporation of Massachusetts Application January 14, 1932. Serial No. 586,588 10 Claims. (Cl. 103-42) so-called meter type dispenser in which the conduit system thereof is always full of liquid and ofter under substantial pressure.

More particularly, the invention relates to an improved valve control for the by-pass connection of such pumps, which connection enables liquid to pass back from the discharge side to the suction side of the pump when the pressure on the discharge side is excessive.

It has been common practice heretofore, to provide a by-pass for the stated purpose and to control such by-pass by an ordinary springpressed relief valve. Such valv is normally held closed under heavy pressure, when the pump is not in operation, and the driving motor for the pump has to start up under a heavy load. With a pump having the ordinary reliefvalve controlled by-pass and used in a gasoline.

, dispensing system of the type above referred to,

the system is normally under relatively heavy pressure, say 15 to 20 poundsper square inch.

The present invention seeks to improve the by-pass valve arrangement by so constructing'it that no substantial amount of pressure can be built up in the dispensing system, while closed, and arranging for the building up of the normal amount of pressure only at times whenthe sys tem is open and operating to make deliveries.

More particularly, the invention provides a bye-pass valve which is normally held to its seat under very small pressure when the pump is stopped or when it is operating with the' outlet of the system closed and which, when the system is in operation to deliver'liquid, is held to its seat under relatively heavy pressure. The suction created by the pump when operating with its outlet open, is .made to increase the pressure which holds the valve to its seat. This arrangement enables the pump to start up under no load,

or at least under no appreciable load, and also enables unloading of thepump when operated with its outlet closed. These and other objects will best appear as the detailed description proceeds andwill' be pointed out in the appended claims.

The invention will be disclosed with reference to the accompanying drawings, in which:

bodying the invention;

' Fig. 2 is a sectional elevational view taken on the line 2--2 of Fig. 1;

Fig. 3 is a sectional plan yiew taken on the line 33 of Fig. 1 showing the by-pass valve p V Fig. 4 is a fragmentary view, taken similarly to Fig. 3 but showing the by-pass valve closed;

. Fig. 5 is across sectional view taken on the line 5-5 of Fig. 3;

Fig. 6 is a sectional elevational view of a gasoline dispenser showing the application of the invention thereto; and

Fig. '7 is an enlarged fragmentary view of a part of Fig. 4.

Referring to these drawings; the invention has been shown for illustrative purposes in connection with a well known form of rotary pump. As shown'in Fig. 3, such pump includes a casing 10, in which is formed a cylindrical chamber 11 for the rotor together with inlet and outlet passages 12 and 13, respectively, communicating therewithr A drive shaft 14, suitably mounted in the casing, passes eccentrically through chamber 11 and has fixed thereto a cylindrical rotor 15, having a series of slots in its periphery to receive blades 16. The rotor is enough shorter than chamber 11 to allow room for two annular rings 17 (Fig. 2), one at each end of the chamber. These rings loosely encompass shaft 14 (Fig. 3) and the" ends of blades 16 are supported on them and held thereby in the outwardly projected positions shown. r

.The inlet passage 12 communicates with a cored passage 18 which extends to and intersects a cylindrical passage 19 .(Fig. 2) near one end thereof. At the other end of passage 19 is an inlet port 20, connected to a suction pipe 21. In the passage 19 is mounted a filter 22, carried by a plug 23, screwed into the Opposite end of passage 19 and closing off communication between the passage 18 and the space in passage 19 around the outside of filter 22. The plug has ports 24 in its wall which enable communication between passage 18 and the space inside the filter. Thus, the pump, when operated, will draw liquid through pipe 21 and port 20 into that part of passage 19 which surrounds the filter 22, thence into and through the filter and out through portsx24 into passage 18 and thence'to passage 12 and rotor chamber 11. Liquid is forced from said chamber through passage 13 into a discharge pipe 25 (Fig. 1). 1

As usually used in a normally closed, pressure- Fig. 1 is an elevational view of a pump emtypegasoline dispensing system, the pump is suitably mounted in a shell or casing 26 and driven by an electric motor 27, as will be clear from Fig. 6. The suction pipe 21 connects withan underground storage tank 28 for gasoline and the discharge pipe 25 extends upwardly for con-- nection to a flexible hose 29, provided at its delivery end with a nozzle 30, having a normally closed valve therein. A suitable meter 31 is interposed in pipe 25 as indicated.

Referring now to Fig. 3, the partition wall 32 which separates the inlet passage 18 from the outlet passage 13, is bored to form a by-pass 33, having a valve seat 34, with which a valve 35 cooperates. Heretofore, this valve has been held to its seat by a spring acting between the valve and a fixed seat or abutment. The arrangement was simply'that of an ordinary relief-valve controlling the by-pass 33, whereby when the pressure in the discharge pipe exceeded a predetermined maximum, the valve 35 would be forced open against the spring to allow liquid to circulate from the outlet to the inlet of the pump and thereby limit the pressure which could be built up by the pump in the discharge line. It is to be noted that in practical use, the pump motor may and often does continue in operation after the valve in nozzle 30 has been closed.

' The present invention affords an improved arrangement, in which the valve 35 is held to its seat by a spring as before, but the spring acts between the valve anda seat or abutment which can be moved. This abutment is movable from a normal position toward the valve seat 34, when a partial vacuum exists in the inlet conduit and from the normal position away from the seat 34, when the pressure exists in said conduit. The arrangement is such that the valve 35 is held closed under relatively small pressure when atmospheric or substantially atmospheric pressure exists in the inlet conduit, as for example, when the pump is first set in operation. This enables the pump to function effectively and create a suction in the inlet conduit and, as a result of the suction created, the valve will be held to its seat under relatively heavy pressure. Then, whenever the valve starts to open to relieve excesspressure in the outlet conduit, the initial movement of the valve away from its seat allows liquid under pressure to flow into the inlet conduit, whereby apressure greater than atmospheric is created there. This results in bodily shifting the valve away from its seat to unload the pump.' Thus, the relief valve, after its initial increment of opening movement, encounters very little resistance to further opening and the resistance diminishes rapidly, allowing the valve to open widely and remain open as long as conditions require. The ordinary relief valve encounters progressively increasing resistance as it opens.

One desirable way of accomplishing these results is shown in Fig. 3. In the outer wall of casing 19, opposite and in alignment with by-pass 33, is an opening into which is screwed one end of a sleeve 36, having a circular flange 37. This flange, and a cup-like member 38 threaded onto it, afford a casing to enclose the mechanism to be described. The member 38 has openings 38' to-allow communication of its interior with the atmosphere. A second sleeve 39 of smaller diameter is slidably mounted in the first sleeve 36 and near its outer end has a circular flange 40. The flanges 37 and 40 are interconnected by a bellows 41. The space within the bellows and between the flanges constitutes an expansible and contractible chamber 42 which is always in communication with the suction passage 18 of the pump but otherwise is closed. This chamber 42 can be evacuated when the pump is delivering liquid or it can fill with liquid under pressure when the liquid deliveries are stopped and the pump is idling or stopped. Communication between passage 18 and chamber 42 is established by way of a plurality of longitudinally disposed grooves 43 in the inner periphery of sleeve 36, whichgrooves extendfrom end to end of the sleeve and open at their inner ends into a counterbored portion 44 of the sleeve. Radial grooves 45 are formed in the outer end face of sleeve 36 to insure communication at all times between each groove 43 and chamber 42. The sleeve 39 has a small flange 46 which at certain times abuts the end face of sleeve 36 to limit the extent of inward motion of sleeve 39 and flange 40 (see Fig. 4) and on this account the radial grooves 45 are necessary to prevent closing off of the communication between chamber 42 and grooves 43.

The valve 35 is fixed to a plunger 48 which is slidably mounted in the inner sleeve 39. The inner end of sleeve 39 carries a collar 49 through which passes the neck 50 of plunger 48. This neck is of slightly smaller diameter than the body of the plunger and at its intersection with such body is a flange 51, which under certain conditions can abut the collar 49 as a stop to limit the movement of the plunger in one direction. The plunger 48 is bored out to receive one end of a spring 52. The other end of this spring presses against a seat 53, which is adjustable, as by the screw thread connection shown, in sleeve, 39. A plug 54 closes the outer end of the sleeve 39 but is readily removable, when required, to allow ac-'- cess to seat 53 for the purpose of adjusting the same.

When a partial vacuum exists in the inlet passage of the pump, the chamber 42 will be partially exhausted and atmospheric pressure will force flange 40 down as far as the engagement of flange 46 with the end face of the fixed sleeve 36 will permit, thus collapsing the bellows 41 and moving the spring seat 53 into its normal position. Valve 35 will then be held to its seat under substantial pressure and can open only after a relatively heavy pressure is built up in outlet passage 12. This condition prevails so long as a suflicient degree of partial vacuum exists in inlet passage 18. This condition ,is illustrated in Fig. 4, from which it will be noted that sleeve 39 has moved down as far as it can go and collar 49 has moved away from flange 51, whereby the full force of spring 52 is exerted to hold valve 35 on its seat 34. Suppose, however, that the valve of nozzle 30 is closed before the motor 27 is stopped. Pressure builds up quickly in outlet passage 13 and forces valve 35 to open against the force of spring 52. As soon as this valve leaves its seat the least bit, the pressure in the inlet and outlet passages will be equalized and the condition of partial vacuum in chamber 42 will no longer exist. The bellows 41 will then expand under the action of spring 52 until the collar 49 abuts flange 51. The valve 35 will then be bodily moved upwardly and will open rapidly, because of the pressure of liquid acting on the movable wall 40 of chamber 42. The sleeve 39 moves up until the collar 49 abuts Range 55 as a stop. From Fig. 7 it will be clear that the abutment of collar 49 with flange 55 does not close oi the grooves 43 so as to prevent comunication of chamber 42 with passage 18. The parts then occupy the relative positions shown in Fig. 3.

The normal position of the bellows is intermediate the two extreme positions shown in Figs.

3 and 4 and one in which the valve 35 is held to its seat simply by the pressure due to the resiliency of the bellows 41 or to a light spring, such as 56, wln'ch may be provided for the purpose if desired. When atmospheric pressure exists in passage 18, the bellows'assumes this normal position and valve 35 is closed but it is held closed by a relatively small force. This arrangement is necessary to enable the pump to function effectively in the first instance and create a suction in passage 18 to draw up liquid from the supply tank 28. However, if after the pump is started the delivery nozzle 30 is still closed, the valve will readily open and unload the pump. That is, the

valve, being held only lightly to its seat, will open quickly as soon as a very small differential is created between the inlet and outlet pressures. Thus; the pump motor 27 can start up without any heavy load thereon. With the ordinary relief valve, the pump would have to build up a heavy pressure, say 15 to 20 lbs. before the by-pass would open. Having the pump in operation, but unloaded as described, assume that the delivery nozzle is opened. The pressure in the outlet conduit is relieved and of course the pressure in the inlet conduit will also drop because of the open by-pass. As soon as the pressure in the inlet passage reaches substantially atmospheric, valve 35 will close Then continued operation of the pump'with its delivery outlet open, will create suction in passage 18, evacuate chamber 42 and compress the spring 52 and hold valve 35 to its seat under heavy pressure, say the 15 or 20 pounds above referred to." Supposing now that the delivery nozzle 30 is closed and the pump allowed to continue in operation. It is soon unloaded. Pressure soon builds up in the outlet passage 13 to an extent to move valve 35 off its seat and on the initial increment of opening movement of this valve, the preseure in the inlet and outlet passages is equalized. The holding forcg therefore effective on valve 35, disappears and the valve opens widely to unload the pump. This is particularly true when the nozzle valve is closed suddenly. The sudden stopping of the swift flowing stream creates a backward surge which immediately opens valve 35. If the pump is then stopped, the valve 35 will remain open, barring leakage in the system which would cause a loss of pressure. The system is normally closed and the liquid therein is under pressure greater than atmospheric, but not very heavy pressure as compared to old standards. Thus, the pump on starting up would normally start up "under no load,.

It is possible in some installations, due to special conditions which prevent maintenance ofpressure greater than atmospheric in the system after the pump has stopped, that the valve 35 might be closed but it would be held closed under relatively small pressure and would start up under no more load than in the case'when the pump was first started after being installed. The point is that the pump cannotbuild up'any substantial amount of pressure in the closed system and it is necessary to open the outlet of the system,- the nozzle 30',before any substantial pressure can be built up.

This arrangement is desirable for reasons of safety,avoiding high pressure on the infiamfined by the append;l claims rather than by the foregoing descriptio What I claim is:

1. In combination, a pump having suction and discharge conduits and a by-pass interconnecting them, a relief valve controlling the by-pass, said pump having a chamber in constant communication with said suction conduit and provided with a movable wall, said valve supported by said wall for movement relatively thereto, and resilient means interposed between said wall and valve.

2. In combination, a pump having suction and discharge conduits and a by-pass interconnecting them, a relief valve controlling the by-pass, said pump having a chamber in constant communication with said suction conduit and provided with a movable wall, said valve supported by said wall for movement relatively thereto, resilient means interposed between said wall and valve, and means for limiting the extent of movement of said wall in each direction. a

3. In combination, a-pump having suction and discharge conduits and a by-pass interconnecting them, and having also an expansible and contractible chamber in constant communication with-said suction conduit, said chamber having a wall movable toward or away from said by-pass according to the presence or absence of suction in said suction conduit, a valve for controlling said by-pass and carried by said wall and mounted for limited movement relatively thereto in a direction toward and away from the by-pass, and a spring acting between said wall and valve tending to move the latter into position to close said bypass.

4. In combination, a pump having suction and discharge conduits and a by-pass interconnecting them, and having also an expansible and contractible chamber in constant communication with said suction conduit, said chamber having a wall movable toward or away from said by-pass according to the presence or absence of suction in said suction "conduit, a sleeve fixed to said wall and projecting toward said by-pass, a piston mounted in said sleeve near one end, a spring seat near the other end of the sleeve, a spring interposed between said seat and piston, a collar on the. first named end of the sleeve to limit the outward movement of the piston by said spring, and

1 5. In'combination, a pump having suction and discharge conduits and a by-pass interconnectingv them having a valve seat, a valve to cooperate with said seat, a sleeve slidably mounted in a wall of said suction conduit in axial alignment with said seat and carrying said valve, flanges provided one on said sleeve and one on said wall, an expansible and contractible bellows interconnecting said flanges and forming therewith a chamber en-. compassing said sleeve, and a passage provided to connect said chamber and suction conduit. v

6. In combination, a pump having suction and discharge conduits and a by-pass interconnecting. them having a valveseat, a valve to cooperate with said seat, a sleeve slidably mounted in a wall of said suction conduit in axial alignment with said seat, flanges provided one on said sleeve and one on saidwall, an expansible and contractible bellows interconnecting said flanges and forming 50 suction conduit and a spring pressed piston mounted within said sleeve and carrying said valve.

.7. In combination, a pump having suction and discharge conduits and a by-pas interconnecting them having a valve seat, a valve to cooperate with said seat, a sleeve slidably mounted in a wall of said suction conduit in axial alignment with said seat and carrying said valve, flanges provided one on said sleeve and one on said wall, an expansible and contractible bellows interconnecting said flanges and forming therewith a chamber encompassing said sleeve, a second sleeve carried by the wall flange and extending toward the other flange and encompassing and guiding the first named sleeve, and an axial groove in one of said sleeves to establish communication between said chamber and suction conduit.

8. In combination, a pump having inlet and outlet conduits and a by-pass interconnecting them, a valve controlling the by-pass, resilient means for moving the valve toward its seat, an abutment between which and said valve said means is interposed, a second resilient means acting on said abutment for holding said valve closed when atmospheric pressure exists in said inlet conduit and means operable by the suction created in said inlet conduit to move said abutment and increase the stress of said flrst named means to hold the valve against its seat with increased pressure.

9. In combination, a pump having inlet and outlet passages and a by-pass interconnecting them and provided with a valve seat, a valve cooperating with said seat to control the by-pass,

resilient means for moving said valve to its seat and holding it there when atmospheric pressure exists in said inlet conduit, an abutment movable by said means, a second-resilient means tending to separate said abutment and valve and through which the force of said first named means is transmitted to said valve, means for limiting the degree of separation of said abutment and valve by said second named means, and means responsive tothe presence of suction in said inlet conduit for moving said abutment in a direction such as to increase the stress of the second named resilient means.

10. In combination, a pump having inlet and outlet passages and a by-pass interconnecting them and provided with a valve seat, said pump having a chamber in constant communication with said inlet passage and provided with a movable wall, a valve to cooperate with said seat and control the by-pass, said valve supported by said wall for movement relatively thereto in a direction toward and away from said seat, resilient means tending to separate said wall and valve, means for limiting the extent of separation oi? the wall and valve by said means, and a second resilient means of less strength than the first named means and acting on said wall and through said first named means on said valve to move the latter to its seat and hold it seated with a relatively light force when atmospheric pressure prevails in said inlet conduit, said wall being movable toward said valve by the suction created in said inlet passage and increasing the stress of the first named resilient means and the force which holds the valve to its seat.

WARREN DE LANCEY.

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