US3329158A

US3329158A - Balanced, single stage-single hose regulator

Info

Publication number: US3329158A
Application number: US353466A
Authority: US
Inventors: John J Geiszler
Original assignee: US Divers Co Inc
Current assignee: Aqua Lung America Inc
Priority date: 1964-03-20
Filing date: 1964-03-20
Publication date: 1967-07-04
Anticipated expiration: 1984-07-04

Description

y 4, 1967 J. J. GEISZLER 3,329,158

BALANCED, SINGLE STAGE-SINGLE HOSE REGULATOR ,Filed March 20, 1964 4 Sheets-Sheet l July 4, 1967 J. J. GEISZLER 3,329,15g

BALANCED, SINGLE STAGE-SINGLE HOSE REGULATOR Filed March 20, 1964 4 Sheets-Sheet 2 INVENTOR. c/o/m/ L/f 66/521 5e July 4, 1967 J. J. GEISZLER 3,329,158

BALANCED S INGLE STAGE- 5 INGLE HOSE REGULATOR Filed March 20, 1964 4 Sheets-Sheet 3 INVENTOR. omv cfi/szzie July 4, 1967 J. J. GElSZliER 3,329,153

BALANCED, SINGLE STAGE-SINGLE HOSE REGULATOR Filed March 20, 1964 4 SheetsSheet 4 Mil 4 i A A n INVENTOR. Lfomv J 65/4245? #rraemexs United States Patent 3,329,158 BALANCED, SINGLE STAGE-SINGLE HOSE REGULATOR John .I Geiszler, Costa Mesa, Calif., assignor to U.S.

Divers Co., Inc., Santa Ana, Calif., a corporation of California Filed Mar. 20, 1964, Ser. No. 353,466 8 Claims. (Cl. 137--505.12)

The present invention relates to fluid flow regulation devices and, more particularly, to a balanced, single stage regulator for passing fluid only upon demand.

Regulators for passing fluid in response to a demand signal are commonly known as demand-type flow regulators. Such regulators find particular use in surface and underwater breathing equipment, generally being located in the air supply line from a tank of compressed air to to the mouthpiece or face mask of the breathing equipment. Basically, demand-type regulators include a control valve which is normally closed to block air flow. By inhaling through the mouthpiece, or through a corresponding port in a face mask, the control valve is momentarily opened to pass a quantity of air from the supply tank into the lungs of the operator.

Unfortunately, the foregoing operation does not always occur with maximum efliciency. In practice, it is often difficult to open the control valve and to draw a sufficient quantity of air through the regulator. is primarily due to the unbalanced design of conventional demand-type regulators wherein the compressed air forces acting on the control valve are opposed by a spring device adapted to maintain the valve normally closed yet ready to open in response to inhalation through the mouthpiece. In such an arrangement, the breathing or suction force required to open the control valve varies with the air pressure in the supply tank. A the air in the tank is used, the tank pressure drops. This directly reduces the compressed air forces acting on one side of the control valve. The spring opposing the compressed air, however, still exerts its original force on the control valve. This means that an increased suction force is required to open the control valve. As more and more air is used, the effort required to inhale through the mouthpiece further increases.

For a diver using underwater breathing apparatus employing a regulator of unbalanced design this presents a serious safety problem particularly at appreciable depths where physical exhaustion can be a rapid process. In such cases, as a greater and greater suction force is required to open the control valve, it becomes increasingly difficult for the diver to receive suflicient volumes of air. His suction effort naturally increases in an attempt to in crease the flow of air through the regulator. This increased eifort accelerates his exhaustion and causes a demand for even greater volumes of air. At this point, even stopping to rest while still under pressure will not case the demand for great volumes of air and the diver begins to gasp for breath. To prevent drowning, the diver must then either return to shallower water where smaller volumes of air are required for normal breathing, or to the surface. In this regard, the newspapers are all too full of accident reports of divers surfacing too quickly from appreciable depths in an attempt to activate sufficient air flow through their breathing equipment.

In an attempt to alleviate the breathing problems associated with unbalanced regulators, two-stage regulators have been devised. In the two-stage regulator, the first stage functions to reduce air pressure to a relatively low value, usually of the order of 50 to 100 p.s.i. (pounds per square inch). The second stage then operates on the low pressure air from the first stage. Unfortunately, the regulation provided by the first stage is still directly affected by variations in air supply pressure which in turn produce similar variations in the pressure of the air supplied to the second stage. Although the air supplied to the second stage does not fluctuate in pressure as much as the air pressure supplied to a single-stage regulator, the fluctuations still are suflicient to produce a material variation in breathing effort as tank pressure drops.

In addition to safety problems of nonuniform breathing characteristics, unbalanced demand-type regulators are, generally speaking, fairly expensive to accurately manufacture. Furthermore, once assembled, the breathing force required to operate the unbalanced type regulators is difficult if not impossible to adjust. Therefore a customer must take a regulator as it comes and is not able to selectively adjust the breathing force to suit his individual requirements.

In view of the foregoing, it is a principal object of the present invention to provide a demand-type regulator which is unaffected by changes in fluid supply pressure.

Another object of the present invention is to provide a highly sensitive, demand-type regulator which utilizes a uniform actuating force at all supply pressures.

Still another object of the present invention is to provide a simple and inexpensive demand-type fluid supply regulator for use with breathing apparatus and the like.

A further object of the present invention is to provide a demand-type fluid supply regulator wherein the actuating force required to open a regulator for fluid flow may be adjusted and set to suit individual needs.

A still further object of this invention is to provide a demand-type regulator for breathing apparatus capable of accurately regulating flow of fluid at. pressures well above p.s.i.

The foregoing as well as other objects and advantages of this invention may be more clearly understood by reference to the following detailed description when considered with the drawings in which:

FIGURE 1 is a perspective view of one form of the regulator of the present invention for use with underwater breathing equipment;

FIGURE 2 is a sectional view taken along the line 2-2 of FIGURE 1;

FIGURE 2A is a sectional view along the line 2A-2A in FIGURE 2;

FIGURE 3 is a sectional view taken along the line 3-3 of FIGURE 2, with a portion of the valve assembly broken away to illustrate the means for actuating the regulator;

FIGURE 4 is a fragmentary sectional view along the line 44 in FIGURE 2;

FIGURE 5 is a sectional front view of another form of the regulator of the present invention;

FIGURE 6 is a sectional view taken along the line 66 of FIGURE 5, with a portion of the valve assembly broken away to illustrate the means for actuating the regulator;

FIGURE 7 is a sectional front view of a further embodiment of the regulator of the present invention; and

FIGURE 8 is a sectional View taken along the line 8-8 of FIGURE 7 illustrating the means for actuating the regulator.

At the outset it should be noted that the regular of the present invention is equally useful in surface and under water breathing equipment and that the essential elements of the regulator are the same regardless of the particular use. Therefore, it is only for illustrative purposes that the regulator is primarily described in connection with underwater breathing equipment, and each embodiment illustrated is in a form which is particularly adapted to such use.

Generally speaking, the regulator is represented by the numeral 8 and includes an outer hollow container 10 divided into two isolated compartments 12 and 14 by a deformable diaphragm 16. The compartment 12 includes a pair of

openings

18 and 20. The opening 18 is designed to securely receive and communicate with a conventional divers mouthpiece 22. The opening 20 functions as an exhaust port normally covered by a movable exhaust valve 24 and leading to an exhaust air deflection assembly 25.

The compartment 14 includes a plurality of openings 26 for passing water as the regulator 10 is submerged into the water.

The diaphragm 16 is deformable into the compartment 12 in response to a reduction in pressure in the compartment 12 relative to the pressure exerted by the water on an opposite surface of the diaphragm. This is generally caused by the divers inhaling through the mouthpiece. In any event, the deformation of the diaphragm 16 into the compartment 12 depresses a lever arm 32 to actuate a novel demand-type valve assembly 28 causing compressed air to pass from a supply tank through a hose 30 to the mouthpiece 22 and into the divers lungs.

Exhalation is also through the mouthpiece 22. The air passing through the mouthpiece into the compartment 12 produces an increase in the air pressure in the compartment 12 sufficient to open the exhaust valve 24. The exhausted air is then vented from the regulator 8 through the exhaust port 20 and the deflection assembly 25.

By way of comparison, when the regulator 8 is incorporated into surface breathing equipment or when a full face mask is employed in underwater breathing equipment, details of the exterior design of the regulator are somewhat altered. The full face mask has a port leading to the compartment 12. This of course does away with the mouthpiece 22. Instead of being located in the compartment 12, the exhaust port 20 is generally located in the side of the face mask thereby eliminating the need for the exhaust air deflection assembly 25. Also, for surface breathing equipment, the compartment 14 may be eliminated and the diaphragm 16 exposed directly to the atmosphere. The remainder of the regulator is as previously described.

Turning now to a more detailed consideration of the structural design of the regulator 8, it is important to note that the valve assembly 28 in each form of the present invention (FIGURES 2, and 7) is quite different than conventional demand-type valve assemblies. The valve assembly 28 is not of an unbalanced design. On the contrary, it is balanced. In principle, this means that the compressed air forces acting on the valve assembly 28 are balanced and remain balanced independent of changes in the pressure of the compressed air. Thus, as air from a supply tank is used during diving, the drop in air pressure within the tank has no noticeable affect upon the breathing effort required to actuate the valve assembly 28. In fact, the breathing force required to actuate the valve assembly remains constant. The diver is therefore able to easily receive suflicient volumes of air at all tank pressures and is not restricted in his movements underwater as tank pressure decreases. In practical tests, this has allowed divers to work for longer periods of time at greater depths than were heretofore generally possible. What is more important, the balanced demandtype regulator of the present invention materially improves the safe-operation of breathing apparatus for underwater as well as surface use.

In addition, since the compressed air forces acting on the valve assembly 28 are normally balanced, the actual magnitude of the air pressure does not alter the valves operation. This means that the regulator of the present invention may operate as a single stage regulator directly upon high pressure air as it comes from the supply tank, thereby eliminating the need for intermediate staging before the demand valve stage in the breathing equipment. Since the regulator of the present invention is relatively inexpensive to manufacture, this results in a material cost 4 reduction both in surface and underwater breathing equipment.

The structural arrangement of one embodiment of the valve assembly 28 resulting in the foregoing balanced design is illustrated in FIGURE 2. As represented, the valve assembly 28 includes a hollow main body 34 having an internal chamber 36 of inwardly stepped radial dimension converging to a circular recess 37 in a closed end 38 of the main body. The main body member 34 also includes a fluid discharge port 40 communicating with the chamber 36 and opposing

side opening

42 and 44 which, as will be described hereinafter, receive the ends of the lever arm 32 employed in the actuation of the valve asse-mbly.

The open end of the main body member 34 is internally threaded at 46 and adapted to receive an externally threaded valve seat member 48. The valve seat member 48 extends into the chamber 36 and includes an outer annular recess 50 receiving an O-ring 52. The O-ring presses against the inner sidewalls of the chamber 36 to prevent fluid from seeping around the valve seat member 48 through the open end of the main body 34. The valve seat member 48 also includes a central passageway 54 for receiving compressed air from the supply hose 30. The passageway 54 extends through the valve seat member 48 and communicates with the chamber 36. The surfaces of the valve seat member 48 within the chamber 36 immediately around the passageway 54 converge toward the passageway and define a valve seat 56 within the chamber 36.

Disposed within the chamber 36 for seating against the valve seat 56 is a valve 58. The valve 58 is arranged for sliding movement within the chamber 36 to and from the valve seat 56 to respectively block and unblock air flow from the passageway 54 to the discharge port 40 and includes a valve head 60 and a valve stem 66.

As illustrated in FIGURE 2A, the valve head 60 includes a plurality of outwardly extending lobes 64 engaging the inner sidewalls of the chamber 36 to provide sliding support for the valve head 60 over and along the chamber 36. A ring 62 of resilient material imbedded in the forward face of the valve head 60 prevents air leakage around the valve seat 56 when the valve 58 is seated against the valve seat.

The valve stem 66 extends rearward from the valve head 60 into the recess 37 and includes an annular slot 68 receiving an O-ring 70 for sealing the recess 37 from the main body of the chamber 36.

Like the valve seat member 48, the valve 58 includes a central passageway 72. The passageway 72 is coaxial with the passageway 54 and extends through the valve head 60 and the valve stem 66 to the recess 37. As illustrated in FIGURE 2, the passageway 72 is of smaller radial dimension than the passageway 54. Therefore, an inner annular portion 63 of the ring 62 imbedded in the head of the valve 58 extends into the passageway 54 normal to the direction of the sliding movement of the valve. Also, the passageway 72 adjacent the recess 37 is of still smaller radial dimension, and the transition between the larger and smaller diameter portions forms an annular shoulder 74 in the passageway 72 upstream from the recess 37. Compressed air from the supply tank engages these surfaces and exerts forces on the valve 58 tending to slide the valve away from the valve seat 56.

In accordance with the present invention these forces are balanced by equal counteracting forces. This is accomplished by careful design of the end surfaces of the valve stem 66 continuously exposed to compressed air in the recess 37. In particular, the end surfaces are constructed to have a surface area normal to the direction of sliding movement of the valve 58 which is equal to the combined surface areas of the inner annular portion of the ring 62 and the shoulder 74 normal to the directions of travel of the valve. Since the air contacting these valve surfaces is at substantially the same pressure, forces are developed on the end of the valve stem 66 toward the valve seat 56 which are equal to the opposing forces acting on the

surfaces

63 and 74 of the valve upstream from the recess. This produces a balance of the compressed air forces on the valve 58 when the valve is against the valve seat. Due to the constancy of the surface areas exposed to the compressed air the balanced condition is maintained independent of changes in air pressure.

Thus as air is drawn by the diver from the supply tank, the reduction in air pressure does not alter the balance of forces acting upon the valve 58 and a uniform breathing force actuates the valve assembly 28 regardless of the value of air pressure acting on the valve 58.

The actual breathing force required to actuate the valve assembly 28 is determined by a coil spring 78. The coil spring 78 surrounds the valve stem 66 with one end pressing against the inner surface of a chamber 36 around the recess 37 and the other end pressing against the rear of valve head 60 toward the valve seat member 48. The spring 78 is pre-loaded and continuously exerts a force on the valve 58 to firmly press the valve surface 62 against the valve seat 56. The coil spring 78 also functions to re turn the valve to its initial position after sliding movement from the valve seat member 40 upon actuation of the valve 58 in response to an inhaling by the operator through the mouthpiece. I

To actuate the valve assembly 28, the uniform spring force exerted by the coil spring 78 on the valve 58 must be overcome. In the present invention this is accomplished by the combination of the diaphragm 16 and the lever arm 32 which in response to an inhaling through the mouthpiece 22 produce a sliding of the valve 58 from the valve seat 56 to allow air to pass from the passageway 54 through the discharge port 40 and into the divers lungs through the mouthpiece.

The diaphragm 16 is circular and as illustrated in FIG- URE 3 includes an annular outer ridge 82 fixedly seated within an annular cup 84 in the container 10. The diaphragm has a high tensile strength yet readily deforms into the compartment 12 in response to very small pressure drops in the compartment 12 relative to the pressure in the compartment 14. In this regard, normal inhaling through the mouthpiece 22 produces a sufiicient reduction in pressure in the compartment 12 to cause a deformation of the diaphragm 16 into the compartment.

The lever arm 32 is formed of a single piece of bent spring wire and includes a substantially horizontal upper end section 86 and a pair of opposing

lower end sections

88 and 90. The upper end section 86 extends horizontally above the end of the valve assembly 28 and below and immediately adjacent the middle of the diaphragm 16. The opposing

lower end sections

88 and 90 extend inwardly through the

side openings

42 and 44 respectively in the main body member 34. Inside the chamber 36, the end sections extend upwardly along the sidewalls of the chamber and then inwardly toward the valve 58 and into a continuous groove 92 in the valve head 60.

When the diaphragm deforms into the compartment 12 in response to an inhalation through the mouthpiece 22, it contacts and presses downward on the upper end portion 86 of the lever arm. The force exerted by the diaphragm 16 upon the lever arm 32 is sufficient to overcome the spring force developed by the coil spring 78. Therefore, the lever arm 32 pivots about the

lower end sections

88 and 90 passing through the

side openings

42 and 44 to rock the ends of the lever arm 32 in the groove 92 in a direction away from the valve seat 56. The lever arm 32 thus slides the valve 58 away from the valve seat 56 to allow compressed air from the passageway 54 to flow between the valve seat 56 and the valve head into the chamber 36 and hence through the mouthpiece 22 and into the divers respiratory system.

At the completion of an inhalation, and just prior to exhalation, compressed air continues to flow through the valve assembly 28 to equalize the pressure in the com partment 12 and 14. The diaphragm then returns to its normal position and the spring 78 forces the valve 58 back against the valve seat 56 to shut off the flow of compressed air into the compartment 12 and to raise the lever arm 32 to its original position.

Upon exhaling, the diver breathes out through the mouthpiece 22 and into the compartment 12 to further increase the pressure within the compartment. This causes the exhaust valve 24 to open momentarily, and allows the exhausted air to exit from the compartment 12 through the exhaust port 20.

As illustrated most clearly in FIGURES 2 and 4, the exhaust port 20 is divided into four open sections by two crossing, mutually perpendicular arms 96 and 98. The intersection of the arms 96 and 98 includes a circular opening 100 fixedly receiving the stem 102 of the exhaust valve 24. The exhaust valve 24 is formed of a deformable material, such as rubber, and includes a cupshaped outer portion 106 extending radially from the stem 102 with an outer annular section 108 extending inwardly toward the outer surface of the container 10 to contact the container within a cup-shaped. recess 110 surrounding the exhaust port 20. The annular section 108 is of relatively thin cross-section and when the diver exhales through the mouthpiece the outer annular sections bends outwardly to provide an escape path for the exhausted air through the exhaust port 20.. At the end of the exhalation the pressure within the compartment 12 drops and the exhaust valve 24 closes to block any further exit of air from or the entry of water into the compartment. The regulator is then ready for the next breathing cycle.

A second embodiment of the present invention employing a balanced demand-type valve assembly is illustrated in FIGURES 5 and 6. In this embodiment, structural features which correspond to those of the embodiment of FIGURES l-4 are represented by primes of the numbers used in FIGURES 1-4.

The main structural differences between the first and second embodiments are in the detailed design of the valve assembly 28' and its means of actuation. Also, the embodiment of FIGURES 5 and 6 includes means for selectively setting the breathing force required to actuate the valve assembly to the individual taste of the operator.

The valve assembly 28 includes a main body portion 112 having a diagonal extension 114 extending through a sleeve 116 secured to the container 10' within the compartment 12'. The extension 114 includes a passageway 118 having an internally threaded open end 120 for coupling to a hose leading from a supply tank (not shown). The passageway 118 leads to an elongated opening 122 in the main body 112. One end 123 of the opening 122 is internally threaded at 124 while an opposite end has an inner region 126 of reduced radial dimension defining an annular shoulder 128 within the main body member and an outer region 129 of increased radial dimension defining an annular shoulder 131 adjacent the region 126.

Extending through the threaded open end 124 into the opening 122 is a valve seat member 130. The valve seat member includes an externally threaded portion for mating with the threaded end 124 and an external head 132 for hand screwing the valve seat member into the opening 122. The valve seat member also includes a central passageway 134 with side ports 136 and 138 leading to a discharge port 140 from the main body portion 112. The end surfaces of the valve seat member 130 immediately around the passageway 134 converge toward the passageway to define a valve seat 142 for a valve 144 within the opening 122.

The valve 144 includes a cylindrical valve head 146 and a valve stem 154. The valve head is supported for sliding movement within the opening 122 to and from the valve seat 142 and includes a valve surface 148 facing and normally engaging the valve seat 142 to block fluid flow from said passageway 118 to said discharge port 140. Preferably, the valve surface 148 includes a disc of resilient material imbedded in the valve head for forming an airtight seal with the valve seat 142. Fluid fiow to the discharge port 140 is further blocked by an O-ring 150 contacting the inner walls of the opening 122 and extending around the valve seat member within a recess 152.

The valve stem 154 extends from the valve head 146 through the open end 126 and is supported for sliding movement within the open end region 126 toward and away from the valve seat 142. Within the opening 122, the stem 154 passes through an O-ring 155. The O-ring 155 presses aaginst the inner walls of the opening 122 and is seated against the shoulder 128 to prevent air from leaking from the opening around the stem 154.

In accordance with the present invention, the valve 144 includes surfaces facing in different directions having substantially equal surface areas normal to the directions of movement of the valve 144. These surfaces are continually exposed to compressed air passing through the passageway 118 when the valve 144 is seated against the valve seat 142 such that equal and opposite forces are developed on the valve along the directions of movement of the valve to produce a balance of the compressed air forces on the valve.

For the valve 144 illustrated in FIGURE 5, such surfaces comprise the annular face 156 of the valve head 146 surrounding the valve stem 154 and the annular portion 158 of the valve head 154 including the valve surface 148 surrounding the valve seat 142. These surfaces are con tinuously exposed to compressed air passing through the passageway 118 when the valve surface 148 is in contact with the valve seat 142 and are of equal and opposing surface area normal to directions of travel of the valve 144. Accordingly, the forces developed by the compressed air on the valve 144 are balanced and remain balanced regardless of changes in the pressure of the compressed air passing through the passageway 118.

The valve 144 is normally urged against the valve seat 142 by a coil spring 160 which extends around the valve stem 154 between the annular surface 156 and a ring 162 seated against an annular shoulder 164 in the opening 122. The coil spring 160 is pre-load'ed to exert a pre-determined force on the valve 144 toward the valve seat 142. The spring force must be overcome to slide the valve 144 from the valve seat 142 to allow passage of compressed air through the discharge port 140 to the mouthpiece 22'.

In the embodiment illustrated in FIGURES and 6, the means for sliding the valve 144 comprises the diaphragm 16 and a bent lever arm 166. The lever arm 166 includes an upper end 168 just below the middle of the diaphragm and the forked lower end 170 having arms 172 extending on either side of the valve stem 154 with

inward extensions

173 and 174 from the arms passing through an end slot 175 in the main body 112 between a pair of

washers

176 and 177. The washer 176 bears against the shoulder 131 while the washer 177 engages the outer surfaces of the

extensions

173 and 174 and the inner surface of an adjusting nut 178 screwed onto a threaded outer end portion 179 of the valve stem 154 external to the main body 112.

In operation, an inhalation through the mouthpiece 22' produces a reduction in pressure in the compartment 12' causing the diaphragm 16 to deform into the compartment. The diaphragm depresses the lever arm 166 causing the

extensions

173 and 174 to pivot at their upper edges against the washer 176 thereby producing a movement of their lower edges against the washer 177 away from the valve seat 142. The washer 177 presses against the nut 179 which in turn carries the valve stem 154 and the valve head 146 away from the valve seat to unseat the valve 144 and to allow aid passage from the passageway 118 through the passageway 134 and into the compartment 12' through the discharge port 140. The compressed air entering the compartment 12 passes into the mouthpiece 22 and hence into the operators respiratory system.

At the end of the inhalation and before an exhalation through the mouthpiece 22, the compressed air entering the compartment 12' through the actuated valve assembly 28 increases the pressure within the compartment 12' to return the diaphragm to its original position. The coil spring 160 then returns the valve 144 against the valve seat 142 to block further air passage through the discharge port and to raise the lever arm 166 to its original position below the diaphragm.

When air is exhaled through the mouthpiece 22', it enters the compartment 12 and exits through the exhaust port 20 as previously described. The breathing cycle is then repeated as desired to supply air to the operators respiratory system.

Since the compressed air forces acted upon by the valve 144 are balanced, and since the spring force of the coil spring remains constant, a uniform breathing force is required to actuate the valve assembly 28' independent of the pressure of the compressed air supplied to the valve assembly. In the form of the invention illustrated in FIG- URES 5 and 6, the force required to actuate the valve assembly 28 may be adjusted and pre-set by the operator to his individual taste. This is accomplished by adjusting the normal position of both the valve 144 and the valve seat member 134 within the opening 122. The position of the valve 144 within the opening may be controlled by turning the adjusting nut 178 while the position of the valve seat member 130 may be controlled by turning the head 132.

The movement of the valve 144 to change its normal position within the opening 122 against the valve seat 144 varies the compression of the coil spring 160 and hence the force normally urging the valve against the valve seat. This, in turn, has the direct effect of varying the breathing force required to depress the lever arm 166 to overcome the spring force exerted by the coil spring 160 on the valve 144. It should be borne in mind, however, that once the breathing force is adjusted, it remains uniform throughout the operation of the breathing apparatus even with changes in the pressure of the compressed air until readjusted by a manual turning of the adjusting nut 176 and the valve seat member 130.

FIGURES 7 and 8 illustrate a third embodiment of the present invention, which combines certain features of the two previously described embodiments, namely a central passage of compressed air through a valve seat member and a valve to an isolated compartment and the external coupling a lever arm to a valve stem external to the main body of the valve assembly for actuation by a diaphragm in response to breathing forces transmitted through a mouthpiece. In FIGURES 7 and 8, elements corresponding to those of the other embodiments are indicated by like reference numerals with the double prime notation.

As illustrated most clearly in FIGURE 7, the left-hand portion of the valve assembly 28" is the same as the valve assembly 28 illustrated in FIGURE 2 and includes a main body member 34" having a chamber 36", a threaded open end 46", and a discharge port 40". An externally threaded valve seat member 48" extends into the chamber 36" and includes a passageway 54" and a valve seat 56".

A valve 58" is supported for sliding movement within the chamber 36" to and from the valve seat 56" to respectively block and unblock the flow of compressed air from the passageway 54" to the discharge port 40-. The valve 58" includes a valve head 60" having a valve surface 62 engaging the valve seat 56", and a valve stem 66" which, instead of terminating in the recess 37", extends through an opening 180 leading from the recess through the main body member 34" to the opposite end of the valve assembly 28". The passageway 72" in the valve 58" extends as far as the recess 37" and includes

side ports

182 and 184 leading to the recess. As in the embodiment illustrated in FIGURE 2 the recess 37" is adjusting nut 178" isolated by the valve stem 66" from the main body to the compartment 36 while air seepage from the recess around the valve stem extending through the opening 180 is prevented by an O-ring 186 within an annular recess 188 in the valve stem.

In accordance with the present invention, the valve 58 includes opposing surfaces having substantially equal and opposing surface areas normal to the directions of movement of the valve such that when the valve contacts the valve seat 56" equal and opposite compressed air forces act upon the valve along the directions of valve movement. Thus, the compressed air forces are balanced and remain balanced regardless of changes in the pressure of the compressed air supplied to the valve assembly 28". To accomplish this, the surfaces of the valve stem 66 within the recess 37 have substantially the same surface area normal to the directions of valve movement as the

surfaces

63 and 74" of the valve upstream from the recess 37".

The valve 58" is normally urged against the valve seat 56 by a coil spring 78, The spring force exerted by the coil spring 78 must be overcome to actuate the valve assembly 28. The lever arm 166" for actuating the movement of the valve 58" in response to a breathing force through the mouthpiece 22" and its coupling to the valve stem 66" are the, same as that described in connection with FIGURES and 6. The lever arm 166 includes a forked end portion 170 with arms .172 extending on either side of the end of the valve stem 66" with inward extensions 173" and 174" passing through a slot 175" in the main body 34 between a pair of

washers

176 and 177". The

washers

176 and 177" are secured about the valve stem 66" by an adjusting nut 178".

In response to an inhalation through the mouthpiece 22", the diaphragm 16" deforms into the compartment 12 and presses downward against the upper end 168" of the lever arm 166'. The lever ar-m 166 pivots about the upper edges of the

extensions

173 and 174" against the washer 176 to produce movement of the valve stem and head away from the valve seat 56" to unseat the valve 58". This allows the passage of air through the valve assembly 28" into the compartment 12' and hence to the operators respiratory system. The remainder of the regulators operation is as previously described-the flow of compressed air returning the diaphragm to its original position at the end of the inhalation and the exhausted air being vented from the regulator by the exhaust valve 24".

Since the compressed air forces acting upon the valve 66 are balanced and since the spring force exerted by the coil spring 78" on the valve remains constant, the same breathing force is required to actuate the valve assembly 28" regardless of changes in the pressure of the compressed air supplied to the valve assembly. As previously indicated, this overcomes the safe breathing problems associated with conventional demand-type flow regulators.

Moreover, in the form of the present invention illustrated in FIGURES 7 and 8, the uniform breathing force required to actuate the valve assembly 28" may be selectively pre-adjusted to suit the individual operator. This is accomplished in the same manner as described in connection with FIGURES 5 and 6, that is by turning the and the valve seat member 48" to control the position of the valve 58 against the valve seat 56" within the chamber 36" and the compression of the coil spring 78". r

In view of the foregoing discussion, it should be appreciated that in each embodiment of the present invention the control valve assembly is of a balanced design wherein the equal and opposite compressed air forces continuously act upon the control valve when closed. Moreover, the balance of forces is maintained regardless of changes in the pressure of the compressed air. This means that a uniform breathing force actnates the flow of compressed air through the regulator regardless of the pressure of the compressed air. This permits the regulator to be directly coupled to a high pressure compressed air supply tank, thereby eliminating the need for intermediate pressure reducing means between the tank and the demand regulator. The use of the demand-type flow regulator of the present invention as a single stage regulation device for an entire breathing assembly materially reduces both the complexity and cost of the valving normally associated with conventional assemblies. Thus, not only does the present invention eliminate the breathing problems associated with conventional demand-type regulators but it also represents a substantial economic savings to the manufacture and consumer of breathing apparatus. Although three separate embodiments of the present invention have been specifically described, they are merely representative of the present invention, which is to be limited in scope only by the following claims.

I claim:

1. In a fluid flow regulator, the combination of:

a main body having a chamber therein, an inlet to said chamber, and a fluid discharge port from said chamber;

a valve seat in said chamber and including a first passageway communicating with said inlet for receiving fluid from a fluid supply;

a valve in said chamber downstream of said valve seat and including a valve head supported for sliding movement within said chamber to and from said valve seat to respectively block and unblock fluid flow between said passageway and said fluid discharge port, a valve stem extending from said valve head into an end of said chamber opposite said inlet to define a compartment isolated from the main body of said chamber by said valve stem, said head and stem including a second passageway communicating with said first passageway and said compartment, said valve further including surfaces. in said compartment and upstream from said compartment having substantially equal and opposing surface areas normal to said directions of movement of said valve such that when said valve head engages said valve seat said fluid continuously exerts substantially equal and opposite forces on said valve along said directions of valve movement to maintain a balance of fluid forces on said valve independent: of changes in fluid pressure;

means for normally urging said valve against said valve seat to block fluid flow;

and means coupled to said valve and extending outside said main body for selectively moving said valve to block and unblock fluid flow as needed through said fluid discharge port.

2. A fluid flow regulator, comprising:

a hollow container having a side opening therein;

a diaphragm secured at its outer edges to and extending across said container to define a first compartment including said side opening, said diaphragm being deformable into said first compartment in response to a reduction in pressure in said first compartment relative to pressure acting on a side of said diaphragm remote from said first compartment;

a valve support'body extending into said first compartment and including an inner chamber, an inlet to said chamber, and a fluid discharge port fromnsaid chamher to said first compartment;

a valve seat in said chamber and including a first passageway communicating with said inlet for receiving fluid from an externally located fluid supply;

a valve in said chamber downstream of said valve seat and including a valve head supported for sliding movement'within said chamber to and from said valve seat to respectively block and unblock fluid flow between sid first passageway and said fluid discharge port, a valve stem extending from said valve 1 1 head into an end of said chamber opposite said inlet to define a second compartment isolated from the main body of said chamber by said valve stem, said head and stem including a second passageway communicating with said said first passageway and said second compartment, said valve further including surfaces in said second compartment and upstream from said second compartment having substantially equal and opposing surface areas normal to said directions of movement of said valve such that when said valve head engages said valve seat said fluid continuously exerts substantially equal and opposite forces on said valve along said directions of valve movement to maintain a balance of fluid forces on said valve independent of changes in fluid pressure; means for normally urging said valve against said valve seat to block fluid flow;

and lever means coupled to said valve and extending without said valve support member to contact said diaphragm such that deformation of said diaphragm into said first compartment depresses said lever to move said valve from said valve seat to unblock fluid flow from said first passageway to said fluid discharge port and thereby through said side opening in said container.

3. In a fluid supply regulator for breathing apparatus the combination of:

a hollow main body member having an elongated chamber with an internally threaded open end, a recess opposite said open end, and a fluid discharge port from said chamber spaced from said open end;

an externally threaded valve seat member mating with and extending longitudinally through said threaded open end of said chamber and into said chamber, said valve seat member including a first passageway through said valve seat member communicating with said chamber for receiving fluid from an external fluid supply and outer surfaces surrounding said first passageway in said chamber defining a valve seat;

a valve including a valve head support for sliding movement along inner surfaces of said chamber to and from said valve seat and having a valve surface for engaging said valve seat to block fluid flow from said first passageway to said fluid discharge port, a valve stem extending from said valve head along said chamber to an end portion received by and supported for sliding movement toward and away from said valve seat Within said recess, and a second passage- Way from said valve surface to said recess through said valve head and stem communicating with said first passageway, said valve further including surfaces on said end portion in said recess and surfaces upstream from said recess having substantially equal and opposing surface areas normal to said directions of movement of said valve such that when said valve surface engages said valve seat, said fluid exerts equal and opposite fluid forces on said valve along said directions of valve movement independent of changes in fluid supply pressure;

means sealing sid recess from the remainder of said chamber when receiving said end portion of said stem;

coil spring means around and extending along said stem between said valve head and an inner surface of said chamber for continuously urging said valve surface against said valve seat;

and means coupled to said valve and extending without said main body for overcoming the spring force of said spring means of said valve to move said valve surface from said valve seat and allow fluid to flow from said discharge port as needed.

4. In a fluid regulator, the combination of:

a main body member having an opening extending therethrough, one end of said opening being internally threaded, a side fluid inlet port through said main body to said opening, and a side fluid discharge port extending through said main body to said opening;

an externally threaded valve seat member mating with and extending longitudinally through said threaded end of said opening, said valve seat member including a passageway from said opening to said discharge port and outer surfaces surrounding said passageway defining a valve seat in said opening;

a valve including a valve head supported for sliding movement along inner surfaces of said opening to and from said valve seat and having a valve surface for engaging said valve seat to block fluid flow from said fluid inlet port to said fluid discharge port, a valve stem extending from said valve head along said opening through an open end thereof opposite said valve seat for sliding movement toward and away from said valve seat, said valve including surfaces having substantially equal and opposing surface areas normal to said directions of movement of said valve, said surfaces being continuously exposed to fluid from a fluid supply through said inlet port when said valve is against said valve seat whereby equal and opposite fluid forces act upon said valve along said directions of valve movement independent of changes in fluid pressure;

means for continuously urging said valve against said valve seat;

means around said stem in said open end for preventing the passage of fluid around said stern through said open end;

and means coupled to said stem external to said main body for selectively sliding said valve within said opening to block and unblock fluid flow as needed through said fluid discharge port.

5. The combination of claim 4 wherein said exposed end of said stem is threaded, and wherein said combination includes an adjusting nut around said threaded end of said stem for changing the position of said valve within said opening.

6. A fluid flow regulator for breathing apparatus, comprising:

a hollow container having a side opening therein;

a diaphragm secured at its outer edges to and extending across said container to define a compartment including said side opening, said diaphragm being deformable into said compartment in response to a reduction in pressure in said compartment relative to pressure acting on a side of said diaphragm remote from said compartment;

a valve support member extending into said compartment from outside said container and including an opening extending therethrough, one end of said opening being internally threaded, a side fluid inlet port to said opening, and a side fluid discharge port from said opening;

a valve including a valve head supported for sliding movement along inner surfaces of said opening to and from said valve seat and having a valve surface for engaging said valve seat to block fluid flow from said fluid inlet port to said fluid discharge port, a valve stem extending from said valve head along said opening and having a threaded end portion passing through an open end of said opening opposite said valve seat for movement toward and away from said valve seat, said valve including surfaces having substantially equal and opposing surface areas normal to said directions of movement of said valve, said surfaces being continuously exposed to fluid from a fluid supply through said fluid inlet port when said valve is against said valve seat whereby equal and opposite fluid forces act upon said valve along said directions of valve movement independent of changes in fluid pressure;

a coil spring around said stem having one end fixed relative to said opening and an opposite end pressing against said valve head to continuously urge said opposite open end of said main body and extending in opposite directions beyond said opposite open end and into the main portion of said opening in said main body to define a compartment isolated from said main portion of said opening and said discharge port, and a second passageway from said valve surface to said compartment through said valve head and stem communicating with said first passageway, said valve further including surfaces around said end portion in said compartment and surfaces upstream from said compartment having substantially equal and opposing surface areas normal to said directions of movement of said valve such that said fluid exerts valve surface against said valve seat; equal and opposite forces on said valve along said means around said stem in said open end of said directions of movement;

opening receiving said stem for blocking fluid seepcoil spring means around and extending along said age around said valve stem; stem between said valve head and an inner surface an adjusting nut received by said threaded end of said 15 of said opening in said main body for continuously stem external to said valve support member for adurging said valve surface against said valve seat; justing the position of said valve within said opening an adjusting nut received by said threaded end of said and for adjusting the spring force exerted by said stem for adusting the position of said valve within coil spring on said valve; said Opening; and lever means coupled to said valve stem external and means coupled to said threaded End Of said valve to said valve support member for contacting said Stem for Overcoming the p g fOfCe of said Spring diaphragm such that deformation of said diaphragm m n 11 Sa d valve to move said valve from said into said compartment depresses said lever to slide Valve at and aH W fluid flow from said discharge said valve within said opening to unblock fluid flow P as Ilefided. through said fluid discharge port to said side open- 8. The combination of claim 7 including a container i i id container surrounding said main body and having a side opening 7. In a fluid supply regulator for breathing apparatus, therein; the bi i of; a diaphragm secured at its outer edges to said cona h ll i b d member i l di an Opening tainer and extending across said container to define therethrough having an internally threaded open end, 3 Compartment including Said Side p g, Said an opposite open end of reduced radial dimension, diaphragm being deformable into Said Compartment d a fl id di h t fro id i b d in response to a reduction in pressure in said commember communicating ith id i partment relative to pressure acting on a side of an externally threaded valve seat member mating with Said diaphragm remote from Said compartment;

and extending 1 i i 11 through i threaded and wherein said means coupled to said threaded end open end, said valve seat member including a fi st of said stem includes a lever extending to contact passageway through said valve seat member for resaid diaphragm Such that rmflti n of said diaceiving fluid from an external fluid supply and outer Phragm into Said compartment depresses Said l r surfaces surrounding said first passageway defining to move Said Valve m Said valve seat. the valve seat; a valve including a valve head supported for sliding References Cited movement along inner surfaces of said opening to UNITED STATES PATENTS and from said valve seat and having a valve surface for engaging said valve seat to block fluid flow 2 gggg from said first passageway to said fluid discharge 2893386 7/1959 sa-eck 142 port, a valve stem extending from said valve head 2921594 1/1960 i 7 64 along said Ope ing to an end portion of reduced radial dimension having a threaded outer end, said 2,951,676 9/1960 Gmget 137.44 XR end portion being supported for sliding movement FOREIGN PATENTS toward and away from said valve seat within said 1,252,444 1 /1960 France.

WILLIAM F. ODEA, Primary Examiner. HAROLD WEAKLEY, Examiner.

Claims

2. A FLUID FLOW REGULATOR, COMPRISING: A HOLLOW CONTAINER HAVING A SIDE OPENING THEREIN; A DIAPHRAGM SECURED AT ITS OUTER EDGES TO AND EXTENDING ACROSS SAID CONTAINER TO DEFINE A FIRST COMPARTMENT INCLUDING SAID SIDE OPENING, SAID DIAPHRAGM BEING DEFORMABLE INTO SAID FIRST COMPARTMENT IN RESPONSE TO A REDUCTION IN PRESSURE IN SAID FIRST COMPARTMENT RELATIVE TO PRESSURE ACTING ON A SIDE OF SAID DIAPHRAGM REMOTE FROM SAID FIRST COMPARTMENT; A VALVE SUPPORT BODY EXTENDING INTO SAID FIRST COMPARTMENT AND INCLUDING AN INNER CHAMBER, AN INLET TO SAID CHAMBER, AND A FLUID DISCHARGE PORT FROM SAID CHAMBER TO SAID FIRST COMPARTMENT; A VALVE SEAT IN SAID CHAMBER AND INCLUDING A FIRST PASSAGEWAY COMMUNICATING WITH SAID INLET FOR RECEIVING FLUID FROM AN EXTERNALLY LOCATED FLUID SUPPLY; A VALVE IN SAID CHAMBER DOWNSTREAM OF SAID VALVE SEAT AND INCLUDING A VALVE HEAD SUPPORTED FOR SLIDING MOVEMENT WITHIN SAID CHAMBER TO AND FROM SAID VALVE SEAT TO RESPECTIVELY BLOCK AND UNBLOCK FLUID FLOW BETWEEN SAID FIRST PASSAGEWAY AND SAID FLUID DISCHARGE PORT, A VALVE STEM EXTENDING FROM SAID VALVE HEAD INTO AN END OF SAID CHAMBER OPPOSITE SAID INLET TO DEFINE A SECOND COMPARTMENT ISOLATED FROM THE MAIN BODY OF SAID CHAMBER BY SAID VALVE STEM, SAID HEAD AND STEM INCLUDING A SECOND PASSAGEWAY COMMUNICATING WITH SAID SAID FIRST PASSAGEWAY AND SAID SECOND COMPARTMENT, SAID VALVE FURTHER INCLUDING SURFACES IN SAID SECOND COMPARTMENT AND UPSTREAM FROM SAID SECOND COMPARTMENT HAVING SUBSTANTIALLY EQUAL AND OPPOSING SURFACE AREAS NORMAL TO SAID DIRECTIONS OF MOVEMENT OF SAID VALVE SUCH THAT WHEN SAID VALVE HEAD ENGAGES SAID VALVE SEAT SAID FLUID CONTINUOUSLY EXERTS SUBSTANTIALLY EQUAL AND OPPOSITE FORCES ON SAID VALVE ALONG SAID DIRECTIONS OF VALVE MOVEMENT TO MAINTAIN A BALANCE OF FLUID FORCES ON SAID VALVE INDEPENDENT OF CHANGES IN FLUID PRESSURE;