US3354902A - Plastic vacuum storage tank - Google Patents

Description

Nov. 28, 1967 F. E. OBERMAIER 3,354,902

PLASTIC VACUUM STORAGE TANK Filed May 11, 1964 1/ Z r 55; J5 0 ZOa, Z9

BY q/ww %W INVENTOR.

United States Patent 3,354,902 PLASTIC VACUUM STORAGE TANK Frank E. Obermaier, Park Ridge, 11]., assignor to The Dole Valve Company, Morton Grove, Ill., a corporation of Illinois Filed May 11, 1964, Ser. No. 366,282 1 Claim. (Cl. 137-496) This invention relates generally to a combined vacuum storage tank and valve assembly and more particularly relates to an improved fluid valve mechanism operative to accommodate flow through the valve in one direction while preventing backflow or leakage through the valve in an opposite direction.

Although the principles of the invention are of general utility, one particularly useful application is made to vacuum systems wherein a vacuum pump or similar apparatus is utilized to withdraw fluid such as air from a given zone or machine such as a vacuum motor. It may be necessary or desirable in such systems to deactivate the vacuum pump while maintaining a vacuum condition in the vacuum motor such as by preventing the backflow or leakage of air to the motor. By means of the present invention, which may effectively serve as a check valve to prevent leakage of air back through the system, a vacuum may be maintained over an extended period of time while the vacuum pump itself remains inoperative.

The present invention is simple in design, easily constructed and assembled, inexpensive in manufacture, rugged, durable and adapted to serve a long, useful life. It is, therefore, an object of the present invention to provide a combined vacuum storage tank and valve assembly for utilization in a vacuum system capable of maintaining a vacuum in the system over an extended period of time.

Another object of the invention is to provide a vacuum storage tank and check valve assembly wherein the valve member cooperates with an abutment wall of the tank to increase the sealing effect of the valve member and to preclude leakage or backflow through the valve member.

Still another object of the invention is to provide a valve mechanism constructed in a manner such that flow through the valve in one direction is accommodated with a minimum pressure differential across the valve while only a minimum reverse acting pressure differential across the valve will preclude bac-kflow or flow through the valve in an opposite direction.

Yet another object of the present invention is to provide a valve mechanism responsive to pressure differential thereacross for opening and closing the valve and wherein the pressure differential required to maintain the valve in a closed position is reduced after the valve has obtained a closed position.

Another object of the present invention is to provide a valve mechanism which is simplein design, is easily and inexpensively constructed and assembled and provides for improved sealing against back-flow.

Many other features, advantages and additional objects of the present invention will become mainifest to those versed in the art upon making reference to the detailed description which follows and the accompanying sheet of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example only.

In the drawings:

FIGURE 1 is a vertical cross-sectional view of a combined vacuum storage tank and valve assembly constructed in accordance with the principles of the present invention;

FIGURE 2 is a side-elevational view of a diaphragm valve member which constitutes one important part of the invention; and

Patented Nov. 28, 1967 ice FIGURE 3 is a vertical sectional view of the valve member taken substantially along lines IIIIII of FIG- URE 2.

As shown in the drawings:

Referring to FIGURE 1,reference numeral 10 indicates generally an illustrative embodiment of the combined vacuum storage tank and valve assembly of the present invention. One important usage of the invention arises in connection with vacuum systems, wherein, a vacuum-producing mechanism such as a vacuum pump may be utilized to reduce the pressure of a fluid such as air in a particular zone or apparatus such as a vacuum motor, and wherein it is necessary or desirable to maintain a vacuum condition in such zone or apparatus for an extended period of time after the vacuum pump has been deactivated.

In contemplation of such exemplary usage, theassembly 10 comprises atank body 11 which may conveniently be assembled from a pair of vertically splithalfportions 12 and 13 bonded together by means of a heat 7 seal at theirmating edges 15, and which may, in its assembled form, assume the general configuration of a barrel. Thebody 11 may be, for purposes of economy of cost and weight, ease in construction and assembly and other considerations, be constituted of plastic material which may be cut out at nonstrategic zones such as at 14 and 16 in order to reduce weight as well as material requirements. In order to prevent collapse of thebody 11 at high vacuum conditions, a plurality of ribs as at 15a are provided to strengthen and to rigidify the body. For mounting purposes aflange plate 17 is formed at the lower end of the barrel-shaped tank, and a pair of slots as at 18 are formed in the'plate to receive respectively a mounting bolt or other suitable fastening device.

In order to connect thetank 11 in a vacuum system a pair ofconnector nipples 19 and 20 extend from the tank body for connection, respectively, to a zone or apparatus in which a vacuum condition is to be produced, such as a vacuum motor, and to a mechanism such as a vacuum pump effective to produce the vacuum condition. Theconnectors 19 and 20 are tubularly shaped with slightly converging end portions to accommodate easy connection to, for example, reinforced air hoses of a vacuum system.

A vertically oriented annularly configurated cavity 21 is formed within thetank body 11 by mating annularrecessed walls 21a and 21b formed in thesplit sections 12 and 13. The annular cavity is, in turn, communicable withflow passageways 19a and 20a formed within theconnectors 19 and 20.

An outlet well 21c, defined by acylindrical wall 22, is formed within the cavity 21 in surrounding relation to an inwardly extendingboss 23, which boss has the innermost end ofpassageway 20a formed therein. A flat annular shoulder is formed in surrounding relation to thewall 22 and has and undercutannular groove 24 formed therein which groove is provided to receive the peripheral beaded portion of a flexible annular diaphragm later to be described.

A flat abutment wall 29 is formed integrally with the righthand half section 13 and presents aflat seating surface 31, which surface is circumscribed by an annular raisedridge 32.

Situated within the well 210 substantially transversely to the direction of flow through such portion and effective to partition such portion into a pair of dividedchambers 33 and 34, is an annular flexible disc-shapeddiaphragm valve member 36. Referring to FIGURES 2 and 3, thevalve member 36 is more particularly characterized as comprising an outer annular rim portion or head 37, an enlarged central portion orprotuberance 38 and a Web 3web portion 39 interconnecting the rim and the central portion.

It will be noted that the" rim portion 37 comprises aback wall 40, aperipheral wall 41 and a front wall 42, and is shaped complemental to the groove 28- (FIG- URE 1) and is fixedly supported thereby in the assembled position of thevalve member 36, such as to produce in effect a seal bead around thevalve member 36 to prevent leakage of fluid about the peripheral edge thereof.

The central portion orprotuberance 38 is generally frustoconically shaped and is axially forwardly offset in the direction of the abutment wall 29, in its assembled position. Theprotuberance 38 is further characterized as comprising a central axial aperture orpassageway 43 and a convergingside wall 44 which terminates in a radially extendingwall member 46. Arecess 47 is formed in thewall 46 such as to form a raisedannular sealing bead 48 encircling theaperture 43.

Theweb 39 is also forwardly inclined and comprises a front wall orface 49, which blends into the side wall 4-4 of theprotuberance 38, and a rear wall orface 50, which blends into arear wall 51 of theprotuberance 38. That portion of therear wall 51 surrounding theaperture 43 forms a cylindircally shaped axially extendingcollar 52.

Thevalve member 36, or at least theweb portion 39 thereof, constitutes flexible material such as rubber so as to accommodate axial movement of the protuberance orcentral portion 38. In the illustrated embodiment, theentire valve member 36 is made of rubber, thereby enhancing the sealing effect thereof between the valve and the engaging surfaces of thetank 11.

Asshown in FIGURE 1, a biasing member orspring 53 is housed within thecylindrical wall 22 in thechamber 33 and bottoms at one end thereof on an inturned portion 54 of thewall 22, and at the other end thereof, on therear wall 51 of thevalve member 36 about thecollar 52. Thespring 53 is constructed such as to impart a constant biasing force on thevalve member 36 in the direction of the abutment wall 29 so as to engage the sealingbead 48 of theprotuberance 38 into theface 31 of the abutment wall 29.

In operation, fluid such as air may be drawn through a bore 56 formed in the inlet connector 19' from a pressurizable zone or apparatus such as a vacuum motor and into the cavity 21 which forms a flow path to thewell 210. A pair of radially extending slots as at 57 are formed in theshoulder portion 32 of the abutment wall 29 to provide flow there through into thechamber 34 on one side of the valve member 36'.

Simultaneously, air is drawn from thechamber 33 on the opposite side of the valve member through a bore 58 formed in theoutlet connector 20, and when the fluid pressure inchamber 33 is reduced sufliciently below that which exists inchamber 34, the biasing force of thespring 53 will be overcome and thefront wall 46 of theprotuberance 38 will move away from and become disengaged with theface 31 of the abutment wall 29. Thus, the fluid inchamber 34 will flow throughaperture 43 of thevalve member 36, which is the only flow path across the valve member, and out through bore 58 to the vacuum pump or similar apparatus.

Upon deactivation of the vacuum pump, fluid pressure inchambers 33 and 34 will become equalized and thespring 53 will again urge the sealingface 46 of the valve member into engagement with theface 31 of the abutment wall 29, and in this closed position, thevalve member 36 acts as a check valve to prevent backflow or leakage fromchamber 33 tochamber 34.

It will be noted, however, that in the closed position of thevalve member 36, as illustrated in FIGURE 1, the area of theface 50 of thevalve member 36 which is subject to fluid pressure in thechamber 33 which pressure acts to urge theprotuberance 38 axially into engagement with theface 31 of the abutment Wall 29, is greater than the area of theface 49 of the valve member which is subjected to fluid pressure in thechamber 34, by that area encircled by theseal bead 48 in engagement with theface 31.

Accordingly, even when the pressure inchambers 33 and 34 is equalized, theseal bead 48 is urged by fluid pressure into good sealing engagement withface 31 by a force which exceeds the force exerted by thespring 53. However, when the vacuum pump again becomes activated and thevalve member 36 is moved to an open position, that is, out of engagement withface 31, the areas on both sides of thevalve member 36 which are subjected to fluid pressure in their respective chambers are equal, thereby reducing the pressure differential necessary across the valve member to maintain the member in an open position.

Although minor modifications might be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably come within the scope of my contribution to the art.

I claim as my invention:

A valve assembly comprising,

a body having a flow path therethrough,

an abutment Wall in said flow path,

a diaphragm supported at its periphery and disposed in said flow path, and

a coil spring engaging and biasing said diaphragm toward said abutment wall,

said diaphragm comprising an outer annular bead, an enlarged central portion and a web portion interconnecting said bead and said central portion,

said central portion being axially forwardly offset in the direction of said abutment wall, said central portion further comprising a central axial aperture, a converging side wall terminating in a radially extending wall member, and a recess formed in said radially extending wall memher to provide a raised annular sealing bead encircling said aperture substantially radially outwardly thereof, said web portion being axially inclined from said annular bead toward said central portion and comprising flat parallel front and rear walls, said rear wall comprising a portion surrounding said aperture and forming a cylindrically shaped axially extending collar for receiving one end of said coilspring to center said spring against said diaphragm.

References Cited UNITED STATES PATENTS 1,910,961 5/1933 Perry 137525 X 3,073,339 1/1963 Stelzer 137527 X WILLIAM F. ODEA, Primary Examiner. H. W. WEAKLEY, Assistant Examiner.

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