US3646974A

US3646974A - Automatic shutoff dispensing nozzle venturi

Info

Publication number: US3646974A
Application number: US21618A
Authority: US
Inventors: Glenn E Moore; Fred A Wilson; Chester W Wood
Original assignee: Dover Corp
Current assignee: Dover Corp
Priority date: 1970-03-23
Filing date: 1970-03-23
Publication date: 1972-03-07
Anticipated expiration: 1989-03-07

Abstract

A continuous groove is formed in the conical bore of a variable venturi body to increase the area in which the liquid flowing therethrough can expand to produce an enlarged low-pressure area. This enlarged low-pressure area enables a diaphragm to be moved to close a main valve even when the flow rate through the venturi is as low as one gallon per minute.

Description

O United States Patent 1151 3,646,974 Moore et al. 1 1 Mar. 7, 1972 AUTOMATIC SHUTOFF DISPENSING 1,250,373 12/1917 Smith ..261/53 NOZZLE VENTURI 2,279,002 4/1942 MacNeil ..137/540 3 224 472 12/1965 Ehlers ..141/209 2 l t l E. M t ;F [7 I ;2 f."g1; 3$ $3 2,320,033 5/1943 Davls, Jr... .......141/209 Cincinnati Ohio 3,085,600 4/1963 Briede ..141/225 x [73] Assignee: Dover Corporation, Cincinnati, Ohio Primary Examiner Edward J Earls [22] Filed: Mar. 23, 1970 Att0rneyKinney and Schenk [21] Appl. No.: 21,618 [57] ABSTRACT A continuous groove is formed in the conical bore of a varia- [52] US. Cl "141/2193; ble venturi y to increase the area in which we liquid 0% 51 1 1111. c1 ...B67d 5/373 ing hemhmugh exPand 1 Pmduce enla'ged [58] Field of Search ..137/540, 604; Sure area- This enlarged low-Pressure area enables a 141/206-211, 214, 215, 21 218, 225, 226, 392; diaphragm to be moved to close a main valve even when the 261/44, 53, 62, DIG. 54, DIG. 56; 138/45; 417/189 flow rate through the venturi is as low as onegallon per minute. [56] References Cited 10 Claims, 5 Drawing Figures UNITED STATES PATENTS 817,721 5111906 Lewis ..261/62 3 s I 1 2'2 a l! Pmmmmmvz 3,646,974

FIG.2

VENTORS GLE MOORE BY FRED wu so- ATTORNEYS FIG-.5

AUTOMATIC SHUTOFF DISPENSING NOZZLE VENTURI In automatic shutoff nozzles of the type shown in U.S. Pat. No. 3,085,600 to Briede, a variable venturi is employed downstream from a main valve, which is operated by a handle lever. This variable venturi has its orifice connected to both a diaphragm suction chamber and the atmosphere. The connection to the atmosphere is through a tube, which is disposed in a spout of the nozzle and has its end communicating with the atmosphere through an opening in the spout. When the level of liquid in the tank being filled by the nozzle covers the opening in the spout for the tube, the orifice creates a suction in the diaphragm suction chamber to cause the main valve to be closed automatically to stop flow through the nozzle.

While the variable venturi of the aforesaid Briede patent operates satisfactorily at medium and high flow rates, this variable venturi does not always operate satisfactorily at a flow rate of less than 2.5 gallons per minute of the liquid. In some instances, this low flow rate of the liquid has not been capable of creating a vacuum in the suction chamber of sufficient power to move the diaphragm to close the main valve. When this occurs, the diaphragm is not moved sufficiently to cause the main valve to close automatically whereby the liquid such as fuel, for example, is lost from the tank being filled and manual actuation of the handle lever must be made by the operator to stop the flow.

Since that flow rate is relatively low, a large quantity of fuel is not lost. However, any fuel on a driveway of a service station, for example, is a fire and explosive hazard. Therefore the variable venturi of the aforesaid Briede patent has presented problems at flow rates under 2.5 gallons per minute.

The present invention satisfactorily overcomes the foregoing problems by providing a variable venturi in which the venturi positively operates at very low flow rates such as one gallon per minute, for example. Thus, the present invention satisfactorily solves the problem of automatically shutting off the flow through the nozzle by moving the diaphragm. This is because the variable venturi of the present invention functions satisfactorily at all times at a low flow rate.

In order for a variable venturi to function satisfactorily, it must not produce a running vacuum in the suction chamber for the diaphragm beyond a predetermined limit. If this limit should be exceeded, then the diaphragm is actuated to prematurely shut off the liquid flow through the nozzle. Therefore, it is a requisite that the variable venturi not produce a running vacuum exceeding the predetermined limit. However, the variable venturi must still produce a predetermined vacuum in the suction chamber for the diaphragm when the tank becomes full even if the liquid flow rate is low.

The present invention satisfactorily meets the foregoing requirements by employing an enlarged area in communication with a conical bore, which cooperates with the surface of the poppet valve to form the venturi. This enlarged area enables the substantially noncompressible liquid to expand after it leaves the throat bore with which the conical bore communicates. This expansion area reduces the velocity of the liquid whereby it has a relatively low pressure.

As a result of the low pressure created in the enlarged area by the expansion of the liquid therein, the airflow to this enlarged area increases because of the low pressure. Thus, even though the flow rate of the liquid may be relatively low, this enlarged area produces a sufficiently low pressure to draw a large quantity of air from the tube communicating with the atmosphere through the opening in the spout.

Because this enlarged area creates a greater orifice effect, a sufficiently low pressure is created in this enlarged area even at a low flow rate. Thus, there is still a relatively large suction created at a low flow rate.

Accordingly, when the liquid level in the tank covers the opening in the spout whereby no additional air can be drawn from the atmosphere, this low-pressure area draws a sufficient amount of air from the suction chamber for the diaphragm very quickly to produce increased power for moving the diaphragm because of the rapid pressure reduction in the suction chamber. This enables the diaphragm to cause the main valve to close faster. Furthermore, it insures that the diaphragm is positively actuated even when the liquid flow rate is very low such as one gallon per minute, for example, because of the low pressure created in the enlarged area due to the expansion of the fluid flowing through the variable venturi construction.

Furthermore, because of the relatively low pressure created by the enlarged area in the conical bore of the variable venturi of the present invention, there is sufficient airflow through the tube from the atmosphere to prevent the vacuum within the suction chamber for the diaphragm from increasing beyond the predetermined limit. This occurs even when the flow rate is relatively low such as one gallon per minute, for example.

Tests have been made to determine the effectiveness of the variable venturi of the present invention in comparison with the variable venturi of the aforesaid Briede patent. With a vacuum of 1% inches of mercury required to actuate the diaphragm to shut off the main valve of the nozzle in the aforesaid Briede patent, the variable venturi of the aforesaid Briede patent, the variable venturi of the aforesaid Briede patent requires a flow rate of two gallons per minute to produce the vacuum of 1% inches of mercury-in the suction chamber. In the variable venturi of the present invention, the vacuum of 1% inches of mercury in the suction chamber was produced with a flow rate of one gallon per minute. Thus, the low flow rate may be reduced in half by the use of the variable venturi of the present invention while still obtaining positive actuation of the diaphragm to close the main valve. Accordingly, the present invention not only enables the main valve of an automatic shutoff nozzle to be positively controlled at a low rate of flow but also insures that the main valve is not shut off prematurely when the nozzle has high flow rate therethrough. Thus, the variable venturi of the present invention produces through a large range of liquid flow rates positive shutoff at the desired time when the tank is filled.

While is would seem that increasing the number of passages providing communication from the conical bore to both the tube in the spout and the suction chamber would produce greater airflow to the conical bore during filling of a tank without requiring the enlarged area of the present invention, increasing the number of the passages would increase the running vacuum in the suction diaphragm chamber beyond the predetermined limit'during high flow rates. Accordingly, this would produce premature shutoff of the main valve at high flow rates.

An object of this invention is to provide a variable venturi capable of causing automatic shutoff of liquid flow through a nozzle at a relatively low flow rate of the liquid.

Another object of this invention is to provide a variable venturi that obtains a maximum orifice effect from the liquid flowing therethrough.

A further object of this invention is to provide a variable venturi that positively shuts off flow through a nozzle in a large range of flow rates without any premature shutting off before a tank, which is being filled by the nozzle, becomes full.

Other objects, uses, and advantages of this invention are apparent upon a reading of this description, which proceeds with reference to the drawing forming part thereof and wherein;

FIG. 1 is a sectional view of a portion of a body of an automatic shutoff noule in which one form of the variable venturi of the present invention is employed.

FIG. 2 is an enlarged sectional view of the variable venturi shown in FIG. I.

FIG. 3 is an enlarged sectional view, similar to FIG. 2, of another embodiment of the variable venturi of the present invention.

FIG. 4 is an enlarged sectional view, similar to FIGS. 2 and 3, showing still another form of the variable venturi of the present invention.

FIG. 5 is an enlarged sectional view of the variable venturi used in the aforesaid Briede patent.

Referring to the drawing and particularly-FIG. 1, there is shown a nozzle body 10 of an automatic shutoff nozzle of the type more particularly shown and described in the copending patent application of W. Donald Boudot, Chester W. Wood and Charles A. Holder for Automatic Shut-Off Dispensing Nozzle," Ser. No. 882,028, filed Dec. 4, I969, and assigned to the same assignee as the assignee of the present application. While the nozzle body is that shown in the aforesaid patent application Ser. No. 882,028, it should be understood that the variable venturi of the present invention may be readily employed with any automatic shutoff nozzle having a pressure responsive means for actuating a main control valve to its closed position on filling of the container by the nozzle. Thus, the variable venturi of the present invention may be readily used with the aforesaid Briede patent, for example.

The nozzle body 10 has a spout adapter 1 1 connected to its outlet by a shearable screw 12. The spout adapter 11 has a nozzle 14 threaded into one end thereof.

The spout adapter 1 1 has a bleeder seat ring 15, which is an annular body, threaded in the other end of the spout adapter 11. The bleeder seat ring 15 has a throat bore 16 (see FIG. 2), which communicates with the inlet of the nozzle body 10 through the main control valve that is operated by a handle lever or the like in the manner more particularly shown and described in the aforesaid application Ser. No. 882,028.

The bleeder seat ring 15 has a conical bore 17 communicating with the throat bore 16 and disposed on the same axis as the throat bore 17. The conical bore 17, which increases in diameter from its intersection with the throat bore 16, communicates with the spout 14 through longitudinal passages (not shown) formed in a spider portion 18 of the spout adapter 1 l.

A poppet valve 19 controls the flow of liquid from the throat bore 16 to the conical bore 17. The poppet valve 19 is slidably supported on the spider portion 18 of the spout adapter 11 by having a stem 20 disposed within an axial passage 21 in a projecting portion 22, which extends from the spider portion 18 of the spout adapter 11.

A spring 23 is disposed in surrounding relation to the projecting portion 22 of the spout adapter 11 and continuously urges the poppet valve 19 to its closed position. As a result, the poppet valve 19 opens only when the main control valve is opened by the operator to allow liquid to flow through the nozzle body 10 and act on the poppet valve 19 to overcome the force of the spring 23.

As shown in FIG. 2, the poppet valve 19 has its surface 24, which engages the bleeder seat ring 15 to close the throat bore 16, diverging away from the surface or wall of the bleeder seat ring 15 defining the conical bore 17. Tests have indicated that the desired orifice effect is obtained when the surface 24 of the poppet valve 19 is at 26 to the axis of the conical bore 17 while the surface or wall of the bleeder seat ring 15 defining the conical bore 17 is at an angle of to the axis of the conical bore 17.

As shown in FIG. 2, the bleeder seat ring 15 is formed with a flat annular surface 25 adjacent the point at which the throat bore 16 terminates. This also is the point at which the surface 24 of the poppet valve 19 engages the bleeder seat ring 15 to stop liquid flow from the throat bore 16 to the conical bore 17.

The bleeder seat ring 15 has a circular surface 26 formed in the wall defining the conical bore 17. The

surfaces

25 and 26 cooperate to form a continuous enlarged area 27, which is adjacent the intersection of the throat bore 16 with the conical bore 17. This continuous enlarged area 27 is an annular groove, which has one of its walls defined by the surface 25 while the other of its walls is defined by a flat annular surface 27, which is parallel to the surface 25. The surfaces 25 and 27' are perpendicular to the axes of the throat bore 16 and the conical bore 17.

Accordingly, the groove is formed in the wall or surface of the bleeder seat ring 15 defining the conical bore 17. If the groove were not formed in the wall or surface of the bleeder seat ring 15 defining the conical bore 17, the conical bore 17 would extend to adjacent the throat bore 16.

This arrangement is shown in FIG. 5 wherein a bleeder scat ring 28, which is utilized in the aforesaid Bricde patent. has its conical bore 29 extending to adjacent the end of its throat bore 30. As a result, the bleeder seat ring 28 has practically no increased area at the end of the throat bore 30 to allow expansion of the liquid when it leaves the throat bore 30 whenever a poppet valve 31 is opened.

The enlarged area 27 communicates through a plurality of radially extending passages 32 in the bleeder seat ring 15 to the exterior of the bleeder seat ring 15. While two of the passages 32 are shown, it should be understood that the present invention functions satisfactorily with only one of the passages 32. However, it is preferred that four of the passages 32 be employed.

As shown in FIG. 1', the passages 32 communicate with an annular passage 33, which is formed between the nozzle body 10 and the spout adapter 11. The annular passage 33 communicates through a passage 34 with a tube 35, which extends through the spout 14. The other end of the tube 35 is disposed at the lower end of the spout 14 and communicates with the atmosphere through an opening in the spout 14in the manner more particularly shown and described in the aforesaid application, Ser. No. 882,028.

The annular passage 33 also communicates with a passage 36 in the nozzle body 10. The passage 36 communicates with a suction chamber, which is formed between a diaphragm and a cap on the body 10 in the manner more particularly shown and described in the aforesaid application, Ser. No. 882,028.

Accordingly, in the manner more particularly shown and described in the aforesaid application, Ser. No. 882,028, the flow of the liquid between the surface 24 of the poppet valve 19 and the conical bore 17 of the bleeder seat valve ring 15 creates an orifice effect to suck the air from the atmosphere through the tube 35. Because of the enlarged area 27, the expansion of the substantially noncompressible liquid after it leaves the throat bore 16 takes place within the enlarged area 27. This produces the very low-pressure area within the bleeder seat ring 15 and adjacent the passages 32.

This low-pressure area creates a void in the enlarged area 27 whereby an increasing quantity of air flows through the passages 32 into the enlarged area 27 for mixing with the fluid flowing therethrough. Thus, the enlarged area 27 creates a greater orifice effect on the passages 32.

With the poppet valve 19 held open due to the flow of liquid through the body 10 and filling of the tank not completed, the air continues to flow through the tube 35 However, as soon as the tube 35 is blocked from communication with the atmosphere due to closing of the opening in the spout 14 by the level of the liquid within the tank being filled, the low pressure created by the enlarged area 27 causes the air within the diaphragm chamber to be sucked therefrom through the passage 36, the annular passage 33, and the passages 32 into the conical bore 17 for mixture with the liquid flowing therethrough.

Because of the very low pressure within the enlarged area 27, this air within the suction chamber is removed very quickly. This sudden drop in the pressure increases the vacuum within the suction chamber rapidly. This exerts a greater force on the diaphragm to cause a quicker movement thereof whereby the main control valve is closed in the manner more particularly shown and described in the aforesaid application, Ser. No. 882,028.

Because of the increased flow of air through the tube 35 as long as the tank is not filled, the running vacuum, which is produced in the suction chamber due to the liquid flowing through the bleeder seat ring 15, is maintained below the predetermined limit at which the diaphragm could be actuated. This situation exists even for the maximum flow rate through the nozzle body 10. This maximum flow rate is 25 gallons per minute.

Referring to FIG. 3, there is shown another form of the present invention in which a bleeder seat ring 37, which is an annular body, has a throat bore 38 and a conical bore 39 communicating with each other with the poppet valve 19 controlling the flow of liquid therethrough in the manner described for the bleeder seat ring 15. in this embodiment, a continuous annular groove 40 is formed in the surface wall of the bleeder seat ring 37 defining the conical bore 39.

The groove 40 has its surfaces or

walls

41 and 42 formed perpendicular to the wall of the bleeder seat ring 37 defining the conical bore 39. Thus, in this embodiment, the groove 40,

which constitutes the enlarged area, is again adjacent the end of the throat bore 38. v

The groove 40 allows the expansion of the liquid in the same manner as the enlarged area 27. The groove 40 communicates with the annular passage 33 through radially extending passages 43 in the bleeder seat ring 37 in the same manner as the passages 32 in the bleeder seat ring communicate with the annular passage 33.

Referring to FIG. 4, there is shown another form of the present invention in which a bleeder seat ring 44, which is similar to the bleeder seat rings 15 and 37, and has a throat bore 45 and a conical bore 46 in communication with each other. The bleeder seat ring 44 has a continuous annular groove 47, which forms the enlarged area in which expansion of the liquid may occur, disposed downstream from the end of the throat bore 45. The groove 47 has its walls or surfaces 48 and 49 disposed perpendicular to the wall of the bleeder seat ring 44 defining the conical bore 46.

While tests have indicated that the maximum efficiency of the groove or enlarged area is at the intersection of the conical bore with the throat bore, it has been found that the present invention functions satisfactorily if the wall or surface 48 of the groove 47 is positioned from the intersection of the conical bore 46 with the throat bore 45 a distance no greater than 0.2 of the diameter of the throat bore 45.

The groove 47 communicates with the annular passage 33 through radially extending passages 50 in the same manner as the groove 40 and the enlarged area 27 do. The flow through the bleeder seat ring 15 is controlled by the poppet valve 19 in the manner described for the bleeder seat ring 15.

While the groove 47 has been shown as having the walls or surfaces 48 or 49 disposed perpendicular to the wall or surface of the bleeder ring 44 defining the conical bore 46, it should be understood that the walls or surfaces 48 and 49 could be disposed perpendicular to the axes of the throat bore 45 and the conical bore 46 in the manner shown in FIG. 2. Furthermore, in any of the embodiments of the present invention, the walls or surfaces of the groove may be disposed at any angle relative to the wall or surface of the body defining the conical bore. it is only necessary that the enlarged area be adjacent the area at which the liquid begins to expand. if the enlarged area is too far downstream from the intersection of the conical bore with the throat bore, the liquid will have completed its expansion before it reaches the enlarged area whereby the desired orifice effect from the expansion of the liquid will not occur. As the flow rate decreases, the expansion of the liquid occurs closer to the intersection of the conical bore and the throat bore of the bleeder seat ring.

While the present invention has been described as actuating a diaphragm to cause closing of the main control valve for the nozzle body, it should be understood that the variable venturi of the present invention may be employed with any pressure responsive means that causes closing of the main control valve. It is only necessary that some type of a suction chamber be provided with which the pressure responsive means is in communication.

flow at low flow rates.

For purposes of exemplificatlon, particular embod|ments of the invention have been shown and described according to the best present understanding thereof. However, it will be apparent that changes and modifications in the arrangement and construction of the parts thereof may be resorted to without departing from the spirit and scope of the invention.

What is claimed is:

l. A variable venturi for an automatic shutoff nozzle including a body having a cylindrical throat bore and a conical bore smoothly merging with said throat bore, said conical bore being disposed on the same axis as said throat bore, a valve to close said throat bore to prevent communication between said throat bore and said conical bore, the outer surface of said valve and the surface of said conical bore diverging from each other away from said throat bore to provide an annular diverging passage therebetween when said valve is open, said body having an enlarged area in said body formed in said conical bore, said enlarged area being in communication with said conical bore to allow expansion of liquid flowing from said throat bore to said conical bore to create a reduced pressure area in said enlarged area, said enlarged area having its surface furthermost from said throat bore located no greater than 0.2 of the diameter of said throat bore along the wall of said body defining said conical bore from the intersection of said throat bore and said conical bore, and said body having means to provide communication between said enlarged area and the exterior of said body for communication with the atmosphere, the flow of liquid through the diverging annular passage between said valve and said conical bore when said valve is open creating a suction effect in said communicating means.

2. The venturi according to claim 1 in which said enlarged area is formed at the intersection of said throat bore and said conical bore.

3. The venturi according to claim 1 in which said communicating means comprises at least one passage extending from said enlarged area to the exterior of said body.

4. The venturi according to claim 1 in which said enlarged area is a continuous groove in said body.

5. The venturi according to claim 4 in which said groove is formed at the intersection of said throat bore and said conical bore.

6. The venturi according to claim 5 in which the walls defining said groove are perpendicular to the axis of said throat bore.

7. The venturi according to claim 5 in which the walls defining said groove are perpendicular to the wall of said body defining said conical bore.

8. The venturi according to claim 4 in which the walls defining said groove are perpendicular to the axis of said throat bore.

9. The venturi according to claim 4 in which the walls defining said groove are perpendicular to the wall of said body defining said conical bore.

10. The venturi according to claim 4 in which said communicating means comprises at least one passage extending from said groove to the exterior of said body.

Claims

1. A variable venturi for an automatic shutoff nozzle including a body having a cylindrical throat bore and a conical bore smoothly merging with said throat bore, said conical bore being disposed on the same axis as said throat bore, a valve to close said throat bore to prevent communication between said throat bore and said conical bore, the outer surface of said valve and the surface of said conical bore diverging from each other away from said throat bore to provide an annular diverging passage therebetween when said valve is open, said body having an enlarged area in said body formed in said conical bore, said enlarged area being in communication with said conical bore to allow expansion of liquid flowing from said throat bore to said conical bore to create a reduced pressure area in said enlarged area, said enlarged area having its surface furthermost from said throat bore located no greater than 0.2 of the diameter of said throat bore along the wall of said body defining said conical bore from the intersection of said throat bore and said conical bore, and said body having means to provide communication between said enlarged area and the exterior of said body for communication with the atmosphere, the flow of liquid through the diverging annular passage between said valve and said conical bore when said valve is open cReating a suction effect in said communicating means.