US3626974A

US3626974A - Demand regulator

Info

Publication number: US3626974A
Authority: US
Inventors: John B Garrison
Original assignee: ATO Inc
Current assignee: Scott Technologies Inc
Priority date: 1969-08-12
Filing date: 1969-08-12
Publication date: 1971-12-14
Anticipated expiration: 1988-12-14

Abstract

A demand regulator chamber closed by a flexible diaphragm exposed on the opposite side to ambient pressure has an outlet leading to a user and an inlet communicating with a pressurized breathing fluid source. A valve actuated by the flexible diaphragm and interposed in the inlet controls admission of breathing fluid to the chamber. A conductor in the chamber confines and conducts breathing fluid from the inlet through the chamber at high velocity to the outlet in a controlled manner assisting the user in opening the valve.

Description

United States Patent John B. Garrison Akron, N.Y. 849,33 1

' Aug. 12, 1969 Dec. 14, 1971 A-T-O Inc. Cleveland, Ohio Inventor Appl. No. Filed Patented Assignee DEMAND REGULATOR 6 Claims, 3 Drawing Figs.

U.S. Cl Int. Cl A62b 7/00 Field of Search 137/4841. 484.6, 494, 224.5, 543, 505.43, 510, 505.35, 63 R, 484.8. 128/1422; 251/303 Relerences Cited UNITED STATES PATENTS 2/1957 Lambertsen 2,728,340 12/1955 Meidenbauer,.lr 137/63 R 2,854,972 10/1958 Cummins 128/1422 3,068,890 12/1962 Tamplen 137/494 3,249,107 5/1966 Delest 128/1422 3,357,447 12/1967 Zarichansky.... 137/494 3,468,307 9/1969 Cummins 137/4842 Primary Examiner-M. Cary Nelson Assistant Examiner-Robert .1. Miller Attorney-Christel and Bean ABSTRACT: A demand regulator chamber closed by a flexible diaphragm exposed on the opposite side to ambient pressure has an outlet leading to a user and an inlet communicating with a pressurized breathing fluid source. A valve actuated by the flexible diaphragm and interposed in the inlet controls admission of breathing fluid to the chamber. A conductor in the chamber confines and conducts breathing fluid from the inlet through the chamber at high velocity to the outlet in a controlled manner assisting the user in opening the valve.

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DEMAND REGULATOR BACKGROUND OF THE INVENTION This invention relates to improvements in protectivebreathing apparatus and, more particularly, to a new and useful valve arrangement in a pressure regulator for controlling the passage of breathing fluid on demand.

Regulators for breathing apparatus of the demand type are known and generally comprise a chamber closed by a flexible diaphragm exposed on its outer face to the pressure of the ambient environment, such chamber communicating with an inhalation hose or mask worn by the user and with a source of oxygen or other breathing fluid through a valve means actuated by the movement of the flexible diaphragm caused by the breathing effort of the user.

It is important in apparatus of this type that the eflort required to be exerted by the user be reduced to a minimum, as close to a normal breathing effort as possible, while providing a high flow of breathing fluid immediately on demand for easier inhalation. To this end, deflectors often are provided to avoid direct impingement of the breathing fluid against the diaphragm which would otherwise tend to oppose the users normal breathing effort. Also, it is desirable to provide an assist for holding the demand valve open so that little effort is required by the user for the greater part of each inhalation, and it is known to direct the fluid flow into the chamber in a manner tending to accomplish this. Such prior art constructions have their advantages, but they customarily permit expansion of the breathing fluid into the chamber, and the resulting loss of control over the fluid flow reduces the effectiveness of such arrangements.

It is known to confine the breathing fluid as it passes through the chamber but not, so far as I am aware, in a manner which realizes the user-assist capabilities of such an approach.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a demand valve having novel means for confining and conducting breathing fluid flow through the demand chamber in a controlled manner to the user.

It is a further object of the present invention to provide a demand valve wherein the stream of breathing fluid is conducted at a high velocity to the user in such a manner as to effect a reduction in pressure in the demand chamber to further draw the diaphragm inwardly thereof and thereby assist the user in actuating the valve.

The foregoing and other objects, advantages and characterizing features of the present invention will become apparent from the ensuing detailed description of an illustrative embodiment thereof, taken together with the accompanying drawing wherein like reference characters denote like parts throughout the various views.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a vertical sectional view of a demand regulator of this invention;

FIG. 2 is a fragmentary view taken about on line 22 of FIG. 1 showing the fluid flow conductor in elevation; and

FIG. 3 is a front elevational view of the demand regulator of FIG. 1.

DETAILED DESCRIPTION OF AN ILLUSTRATIVE EMBODIMENT Referring now in detail to the drawing, there is shown one form of a demand regulator, generally designated 10, of the present invention comprising a hollow body or casing 12 having a flexible diaphragm 14 secured across the open side of casing 12 to define a breathing chamber 16 therein. Diaphragm 14 is provided with an enlarged, annular head 18 formed on the peripheral edge thereof and clamped between

annular flanges

20 and 22 of casing 12 and a cover 24. If desired, other suitable means can be employed to secure diaphragm 14 in place. Cover 24 is secured to casing 12 as by means of an annular, generally U-shaped retainer clamp 26 enclosing

flanges

20 and 22 of casing 12 and cover 24, respectively. Cover 24 provides a protective cover enclosing diaphragm l4 and is provided with a plurality of openings 28 communicating with the ambient environment. Casing 12 is provided with an inlet passage 30 adapted for connection to a source of breathing fluid under pressure, not shown, and carries a fitting providing an outlet 32 adapted for communication with the inhalation hose or breathing mask of the user, also not shown.

Diaphragm 14 has a reinforcing wear plate 34 secured thereto and engageable with the outer end of a tilt valve stem 36. Thus, upon demand, that is, upon inspiration by the user the pressure in chamber 16 will be lowered relative to the ambient pressure acting externally on diaphragm 14, thereby causing diaphragm 14 to move inwardly of chamber 16, tilting valve stem 36 in a clockwise direction as seen in FIG. 1.

Fluid inlet 30 opens into an inlet chamber 38 communicating with breathing chamber 16 through a valve housing, generally designated 40. Valve housing 40 has an enlarged end portion 42 suitably attached to a portion of casing 12. Valve housing 40 is provided with a conically shaped bore 44 terminating in an orifice 46 which is surrounded by an annular valve seat 48 projecting into chamber 38.

A demand valve body 50 is secured to the inner end of stem 36 and is provided with a plurality of radially outwardly extending guide fingers 52 which serve to center demand valve 50 by sliding engagement with a cylindrical bore 54 in chamber 38. Valve 50 is provided with a resilient sealing surface 56 in sealing engagement with valve seat 48. Inlet fluid pressure urges valve body 50 into sealing engagement against seat 48, whereas movement of diaphragm 14 into chamber 16 tilts stem 36 against the restoring action of said fluid pressure, pivoting valve body 50 along with its sealing surface 56 on and away from valve seat 48. This opens orifice 46, admitting breathing fluid under pressure from inlet 30, through chamber 38 and into chamber 16. The inlet end of housing 40 keeps valve body 50 captive within chamber 38.

It is a particular feature of this invention that the fluid flow resulting from opening valve 50 is substantially confined and conducted directly to the user for easier inhalation and in a manner assisting the user in further opening the valve. To this end, there is provided a fluid conductor 64 in the form of a curved tubular conduit having a base 66 seating on the inner wall surface of casing 12, around and against the enlarged end of valve housing 40. Conductor 64 is secured in position as by screws 68 (FIG. 2) extending into casing 12 thereby securing the conductor in position and simultaneously holding valve housing 40 in mounted position.

Conductor 64 is generally circular in cross section and is arcuately bent at approximately to provide a passage having an inlet 70 in registry with orifice 46 and an outlet 72 in coaxial alignment with outlet 32 which, in the illustrated embodiment, is directly opposite diaphragm 14. A guide slot 74 is provided in conductor 64 of a width and length sufficient to accommodate movement of stem 36 and guide the same in its tilt path. Also, an aspirating opening 76 is provided at the inlet end of conductor 64 adjacent base 66 and on the side thereof opposite diaphragm 14 to assist the user in actuation of diaphragm 14 upon inhalation, as will be described.

Thus, upon cracking valve body 50 open as a result of inhalation by the user, breathing fluid under pressure is admitted from inlet 30, through inlet chamber 38 into conductor inlet 70 and is conducted by conductor 64 through chamber 16 and conductor outlet 72 to the user. The breathing fluid is thus confined within conductor 64 in its passage through chamber 16, instead of expanding into the chamber with resulting loss of control over the fluid stream, and flows at high velocity from the inlet to the user without the loss of velocity which would accompany expansion in chamber 16. Direct impingement of the incoming breathing fluid upon diaphragm 14 is avoided, thereby eliminating resistance to the demand influence of the user. The slight amount of breathing fluid which escapes through slot 74 is so negligible as to present no measurable loss of velocity or objectionable contact with diaphragm 14, it being understood that slot 74 is only as wide and as long as is necessary to accommodate tilting of stem 36.

in addition to conducting the breathing fluid stream away from direct impingement with diaphragm l4 and toward outlet 32, the issuance of the stream from outlet 72 of conductor 64 at high velocity in outlet 32 causes the stream to behave in the manner of a venturi tending to further increase the pressure differential moving diaphragm 14 into chamber 16. Thus, the high-velocity flow of pressure fluid existing at outlet 72 which is positioned within outlet 32, tends to further reduce the pressure acting internally against diaphragm 14, thereby assisting the user in producing further inward movement of diaphragm 14 and further opening of valve 50. To this end, the configuration of conductor 64 is important, because it acts as a continuation of orifice 46, confining and shaping the incoming pressure fluid and delivering it to the outlet in a smooth and continuous manner producing the desired result. The coaxial arrangement of conductor outlet 72 in chamber outlet 32 provides an uninterrupted annular opening therebetween which enhances the desired venturi effect.

It is also a feature of this invention that the pressure in chamber 16 is further reduced by passage of the fluid stream through chamber 16, this being accomplished by the provision of aspirator notch or opening 76 which, as previously noted, is adjacent the inlet end of conductor 64 on the side thereof opposite diaphragm 14. It has been found that the provision of such an aspirator opening significantly improves the regulator performance, apparently because the high-velocity fluid stream flowing past or across opening 76 creates a pressure differential tending to draw fluid from chamber 16 through opening 76, thereby further reducing the pressure in chamber 16 and assisting the user.

It also has been found that locating aspirator notch on the side of conductor 64 opposite diaphragm 14 produces the desired result, whereas positioning it on the side of conductor 64 facing diaphragm 14 apparently does not. The construction and arrangement of conductor 64, to provide a conduit which is spaced from the chamber-defining walls except for mounting at its inlet end, therefore also is important in permitting" such locating of the aspirator notch.

The relative location and arrangement of aspirator opening 76 and

venturi outlet

32, 72 is such that neither one interferes with the other, and the two work together to facilitate and assist the user in opening valve 50 on demand.

A plate 80 secured to diaphragm 14 on the side opposite chamber 16 has a rod 82 extending outwardly therefrom and projecting through a central opening provided in cover 24. An actuating member 84 is secured to the outer end of rod 82, and a helical spring 86 is disposed between the inner surface of member 84 and the outer surface of cover 24. Member 84 can be actuated by hand against the bias of fluid pressure on valve 50 to move diaphragm 14 inwardly and thereby provide flow of breathing fluid to purge the passageway from the valve to the user.

From the foregoing, it is apparent that this invention fully accomplishes its intended objects. Breathing fluid flow is confined and channeled at a high-velocity to the user without expansion thereof into the breathing chamber or direct impingement against diaphragm 14, and in a manner assisting in producing further inward movement of diaphragm l4 and further opening of valve 50.

While reference has been made throughout to a flexible diaphragm this invention is adapted for use with any other type of movable wall member.

A preferred embodiment of this invention having been described in detail, it should be understood that this has been done by way of illustration only.

I claim: 1. A demand regulator for breathing apparatus comprising:

a casing; a movable member defining a chamber on one side of said movable member in said casing; said movable member being responsive to pressure reduction in said chamber; said casing having a fluid inlet communicating with said chamber and adapted for connection to a source of breathing fluid under pressure; said casing having a fluid outlet adapted for connection to breathing apparatus; valve means responsive to movement of said member for controlling the flow of breathing fluid through said inlet; and a conduit extending through said chamber, said conduit having an inlet in registry with said casing inlet and an outlet in registry with said casing outlet for confining the breathing fluid flow admitted through said casing inlet and conducting said fluid flow to said casing outlet; said conduit outlet being substantially coaxially aligned within said casing outlet and maintaining said fluid flow at a high velocity to effect a further reduction in pressure in said chamber and thereby assist a user in opening of said valve means, said valve means being a tilt valve having a valve body and a stem extending therefrom into the path of movement of said member for engagement thereby, and said conduit being provided with a slot for accommodating tilting of said valve stem.

2. A demand regulator as set forth in claim 1, wherein said conduit has an aspirator opening adjacent said conduit inlet on the side thereof opposite said movable member and maintains fluid flow across said aspirator opening at high velocity to effect a further reduction in pressure in said chamber and thereby assist a user in further opening of said valve means.

3. A demand regulator as set forth in claim 1, wherein said casing outlet is substantially directly opposite said movable member.

4. A demand regulator according to claim 3 wherein said conduit inlet is at generally a right angle to said conduit outlet, and wherein said conduit has an aspirator opening adjacent said conduit inlet on the side of said conduit opposite said movable member, the high-velocity fluid flow maintained across said aspirator opening by said conduit effecting a further reduction in pressure in said chamber thereby to assist a user in opening said valve means.

5. A demand regulator according to claim 1 wherein said movable member is a flexible diaphragm.

6. A demand regulator for breathing apparatus comprising: a casing; a movable member defining a chamber on one side of said movable member in said casing; said movable member being responsive to pressure reduction in said chamber; said casing having a fluid inlet communicating with said chamber and adapted for connection to a source of breathing fluid under pressure; said casing having a fluid outlet adapted for connection to breathing apparatus; valve means responsive to movement of said member for controlling the flow of breathing fluid through said inlet; and a conduit extending through said chamber for confining the breathing fluid flow admitted through said inlet and conducting said fluid flow to said outlet, said conduit having an aspirator opening therein adjacent said inlet and on the side of said conduit opposite said movable member.

Claims

1. A demand regulator for breathing apparatus comprising: a casing; a movable member defining a chamber on one side of said movable member in said casing; said movable member being responsive to pressure reduction in said chamber; said casing having a fluid inlet communicating with said chamber and adapted for connection to a source of breathing fluid under pressure; said casing having a fluid outlet adapted for connection to breathing apparatus; valve means responsive to movement of said member for controlling the flow of breathing fluid through said inlet; and a conduit extending through said chamber, said conduit having an inlet in registry with said casing inlet and an outlet in registry with said casing outlet for confining the breathing fluid flow admitted through said casing inlet and conducting said fluid flow to said casing outlet; said conduit outlet being substantially coaxially aligned within said casing outlet and maintaining said fluid flow at a high velocity to effect a further reduction in pressure in said chamber and thereby assist a user in opening of said valve means, said valve means being a tilt valve having a valve body and a stem extending therefrom into the path of movement of said member for engagement thereby, and said conduit being provided with a slot for accommodating tilting of said valve stem.