US3493011A - Demand valve - Google Patents

Description

Feb. 3, 1970 J. T. cARuso 3,493,011

DEMAND VALVE Filed Hay 2, 196e,

INVENTOR. .)57222 I' Caras@ ATTORNEYS.

United States Patent O 3,493,011 DEMAND VALVE John T. Caruso, Kenmore, N.Y., assignor to Automatic Sprinkler Corporation of America, Cleveland, Ohio Filed May 2, 1966, Ser. No. 547,010 Int. Cl. F16k 17/34 U.S. Cl. IS7-484.2 4 Claims ABSTRACT F THE DISCLOSURE This invention relates to the protective breathing field, and more specifically to a new and useful valve arrangement in a pressure regulator for controlling the passage of breathing fluid on demand.

It is important in apparatus of this type that the effort required to be exerted by the user be reduced to a minimum, as close to a normal breathing effort as possible. It is also desirable to provide a high flow of breathing fluid immediately on demand, thereby satisfying the demand for breathing fluid as rapidly as possible.

Accordingly, a primary object of this invention is to provide a demand valve requiring a relatively low cracking force, providing a relatively high flow of breathing fluid immediately upon being cracked open and which tends to assist the user in further opening the valve upon initial cracking thereof.

Another object of this invention is to accomplish the foregoing in a relatively simple, durable and dependable manner.

Breathing apparatus constructed in accordance with the instant invention is characterized -by the provision of a demand valve having a generally semi-circular orifice into a breathing chamber defined in part by a flexible diaphragm, a valve body engaging an orifice sealing surface and having a stem projecting into the chamber Ifor movement by the diaphragm in a plane, the orifice being generally symmetrical about that plane and positioned generally between the stem and the diaphragm, and a flow director on the chamber side of the orifice, the director having a top wall positioned between the valve stem and the diaphragm and opposite side walls defining with the top wall a generally U-shaped hood inverted relative to the diaphragm and directed across the diaphragm to the fluid if outlet.

The foregoing and other advantages and characterizing features of the demand regulator of this invention will become clearly apparent from the ensuing detailed description of the illustrative embodiment thereof depicted in the accompanying drawing wherein like reference numerals denote like parts throughout the various views and wherein:

FIG. 1 is a view partly in section and partly in side elevation, showing a demand regulator of this invention;

FIG. 2 is an end view of the fluid flow director thereof, taken about on line 2-2 of FIG. 1 with all but the director and its attaching screws omitted for greater clarity and ease of illustration;

FIG. 3 is a similar, opposite end View thereof, taken about on line 3 3 of FIG. 1;

FIG. 4 is an end view of the valve seat disc, taken about on line 4 4 of FIG. l and with all but the valve seat disc omitted `for greater clarity and ease of illustration; and

FIG. 5 is a similar, opposite end view thereof, taken about on line 5-5 of FIG. 1.

Referring now in detail to the embodiment depicted by way of illustration in the accompanying drawing, there is shown a regulator having a hollow casing 1. A flexible diaphragm 2 is secured across the open side of casing 1 to define a breathing chamber 3 therein. Diaphragm 2 can be secured in place by any desired means, including for example a locking band 4, and has a reinforcing wear plate 5 engaging the outer end 6 of a tilt valve stem 7. A cover 8 is secured to casing 1, as by screws, one of which is shown at 10, and provides a protective cover enclosing diaphragm 2. Casing 1 is provided with an inlet passage 11 adapted Ifor connection to a source of breathing fluid under pressure, not shown, and an outlet 12 adapted for communication with the breathing mask of the user.

Thus, upon demand, that is, upon inspiration by the user the pressure in chamber 3 will be lowered relative to the ambient atmospheric pressure acting externally on diaphragm 2, thereby causing diaphragm 2 to move inwardly of chamber 3, tilting valve stem 7 in the plane of the paper.

Fluid inlet 11 opens into an inlet chamber 13 connecting with breathing chamber 3 through a valve disc generally designated 14. Valve disc 14 seats against a shoulder 15, with a sealing gasket 16 interposed therebetween. Disc 14 is dished, inwardly of chamber 13, and has a semicircular kidney-shaped fluid orifice 17 therethrough. Orifice 17 is surrounded by a valve seat having a generally semi-circular portion 18 substantially coincident with the curved outer circumference of orifice 17. The valve seat is completed by a generally rectilinear portion 19 extending crosswise of the opposite ends of orifice 17, between the opposite ends of the curvilinear seat portion 18.

The inner circumference of orifice 17 is defined by a tab 20 apertured to loosely receive stern 7.

A circular valve body 21 is secured to stem 7 at its inner end, and has a suitable sealing material surface 22 seating against the valve seat 18, 19 in sealing engagement therewith. A helical spring 23 encircles stern 7, seating at one end in an annular recess 24 in valve disc 14 and bearing at its opposite end against a stop 25 on stem 7. Spring 23 urges valve body 21 into sealing engagement against seat 18, 19, whereas movement of diaphragm 2 into chamber 3 tilts stem 7 against the restoring action of spring 23 pivoting valve body 21 with its sealing surface 22 centrally on the curvilinear seat portion 18. This opens orifice 17, admitting breathing fluid under pressure from inlet 11, 13 into chamber 3. It is a particular feature of this invention that the fluid flow thus resulting from cracking upon valve 21 is directed and utilized in a manner assisting the user in further opening the valve.

To this end, there is provided a flow director 25 having a base 26 seating on the inner wall surface of casing 1, around and against valve disc 14. Director 25 is secured in position as by screws 27 extending into casing 1, thereby securing the director in position and simultaneously holding valve disc 14 in mounted position.

Director 25 has an opening 28 therethrough, in general alignment with orifice 17, and is formed to provide a hood having a curved top Wall portion 29 and opposite side wall portions 30. The director hood therefore is of generally inverted U-shape, as viewed in FIG. 1, with top wall 29 positioned between stem 7 and diaphragm 2. Stem 7 extends between the hood side walls 30, outwardly beyond the hood, with top wall 29 having a down turned outer end 31 terminating short of stem 7 in its centered, rest position.

The axes of orifice 17 and director 25 are inclined upwardly toward diaphragm 2, in the direction of fluid flow, and also toward outlet 12 which is positioned lgenerally opposite inlet orifice 17. The director 25 is positioned and anged to direct the incoming fiuid fiow across diaragm 2 toward outlet 12. In other words, it ldoes not rely defiect incoming pressure fiuid from direct imlgement upon the diaphragm. It does more than that, that it directs the fiuid flow relative to the diaphragm a manner tending to further increase the pressure differtial moving diaphragm 2 into chamber 3. In other rds, the high velocity fiow of pressure fluid across tphragm 2 tends to further reduce the pressure actin-g :ernally against the diaphragm, thereby assisting in Jducing further inward movement of diaphragm 2 and rther opening of the valve 21. In doing this, the genilly inverted U-shape of the director hood is important, cause it acts as a continuation of orifice 17, confining d shaping the incoming pressure fluid in a manner oducing the desired result. The desired alignment between orifice 17 and the rector hood is assured by a position lock 32 on valve sc 14 which is received in 'a recess 33 in the base of rector 25. The circular, symmetrical shape of valve body and its Sealing surface 22 avoids any need for pretermined angular orientation between the valve body ,d its seat. Having fully disclosed and completely described my vention, what I claim as new is: 1. A breathing apparatus having a hollow casing with l opening in one wall thereof, a movable member selred across said opening to define an expansible chamber said casing, said casing having a fluid inlet communi- ,ting with said chamber and adapted for connection to source of breathing fluid under pressure and a fluid outt communicating with said chamber, means forming a :nerally semi-circular orifice between said fluid inlet 1d said chamber at a position generally opposed to said lid outlet across said chamber, valve means operably ;sociated with said orifice for controlling the liow of reathing fiuid therethrough into said chamber, said tlve means including a valve body and a valve seat ving an orifice sealing surface on the inlet end of said rifice remote from said chamber, said movable member :ing responsive to variations in differential pressure ithin and without said chamber, a valve stem projectlg from said valve body into said chamber for movelent by said member in a plane tilting said valve body on said valve seat to open the fluid passage through said orifice upon movement of said member into said chamber, said orifice being generally symmetrical about said plane and positioned generally between said stem and said member, and a fluid flow director on the chamber side of said orifice, said director having a top wall positioned between said valve stem and said member and o-pposite side walls defining with said top wall a lgenerally U-shaped hood inverted relative to said member and directed thereacross to said fluid outlet, said director and said orifice coacting in a manner tending to further increase the pressure differential moving said member into said chamber upon fiuid fiow through said orifice thereby assisting in further opening of said valve means.

2. A breathing apparat-us as set forth in claim 1, wherein said movable member is a flexible diaphragm.

3. A breathing apparatus as set forth in claim 2, wherein said orifice and said flow director are inclined relative to said diaphragm in the direction of said fluid outlet.

4. A breathing apparatus as set forth in claim 2, wherein said valve seat has a generally semi-circular portion aligned with said orifice and joined at the opposite ends thereof by a generally fiat portion extending generally normal to said plane, said orifice being defined in part by a tab bisected by said plane and extending generally from said fiat seat portion toward the mid-point of said semi-circular seat portion, said tab being spaced from said semi-circular seat portion to define the inner circumference of said orifice and being apertured to receive said valve stem.

References Cited UNITED STATES PATENTS 3,095,890 7/1963 Cousteau et al. 3,236,250 2/1966 Colombo. 3,357,447 12/1967 Zarichansky 137-494 2,445,359 7 1948 Meidenbauer. t 3,145,721 8/1964 Miller.

WILLIAM F. ODEA, Primary Examiner RICHARD GERARD, Assistant Examiner U.S. C1. X.R. 137--494

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