United States Patent 3633611

A second-stage single hose regulator includes an inlet valve extending diametrically across the bottom of the regulator chamber with an outlet orifice pointing directly into the mouthpiece tube. A valve-actuating lever is connected between the valve and a diaphragm extending across the housing, and a pair of exhaust ports and associated check valves are provided in the wall of the housing diametrically opposite to the mouthpiece.

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B63C11/22; (IPC1-7): B63C11/22
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Primary Examiner:
Nelson, Cary M.
Assistant Examiner:
Gerard, Richard
I claim

1. In a pressure regulator of the type including a recessed housing having a diaphragm mounted across said recess to define a chamber in said housing, a fluid inlet, a valve including a housing and a valve element connected between said inlet and said chamber for admitting fluid under pressure to said chamber, a fluid outlet from said chamber extending through said recessed housing, a lever member interconnected between said diaphragm and said valve for actuating said valve in response to movement of said diaphragm relative to said recessed housing, and a spring for biasing said valve element into a closed position, the improvement wherein

2. The invention according to claim 1 wherein said valve element is provided intermediate its ends with a flange against one face of which said spring operatively abuts and said flattened ends of said lever abut against the opposite face of said flange.

3. The invention according to claim 2 wherein

4. The invention according to claim 2 wherein

5. The invention according to claim 1 wherein

6. The invention according to claim 1 wherein

7. In underwater breathing apparatus, the combination of

8. The combination of claim 7 wherein said housing is generally cup-shaped, having a cylindrical sidewall and a tapered bottom wall,

9. The combination of claim 7 wherein said exhaust outlet comprises

The present invention generally relates to underwater breathing apparatus, and it more particularly relates to a second-stage regulator of the type employed in self-contained underwater breathing apparatus.

The present invention constitutes an improvement over second-stage regulators of the type now known in the prior art, one such type being described in U.S. Pat. No. 3,179,118 to Mitchell et al. and assigned to the same assignee as the present invention.

Before considering the various aspects of the present invention as they are embodied in the pressure regulator illustrated in the drawings and described in detail hereinafter, certain desiderata of self-contained underwater breathing apparatus bears discussion and may be helpful to a better understanding of this invention.

Self-contained underwater breathing apparatus, better known as SCUBA, generally includes a portable tank containing pressurized air, a first-stage pressure regulator mounted directly on the tank, and a second-stage regulator. The purpose of the first-stage regulator is to supply air to the second stage at a constant pressure even though the pressure in the tank necessarily decreases as the air supply therein is being used. The second-stage regulator controls the supply of air to the driver so as to feed air to him whenever he inhales and to disrupt the flow of air whenever he stops inhaling. In the case of a single hose second-stage regulator, the regulator also incorporates means to exhaust the gases exhaled by the diver.

In order to respond to inhalation by the diver, second-stage regulators of the type now being used sense the pressure differential between the ambient and the diver's mouth, and for optimum performance the regulator should respond to a very slight negative pressure differential at the diver's mouth. Once the regulator responds to this negative pressure differential and opens the air feed line to the diver, air should be supplied at a rate of flow which approximates the rate of flow of air to a person's lungs under normal breathing conditions. Although the ambient pressures normally encountered by divers varies throughout an exceedingly wide range, this flow rate should, nevertheless, remain relatively constant. Moreover, since these regulators must be manufactured on a quantity production basis in order to be sold at a competitive price, it is desirable that they be of a design which minimizes variation in this flow rate from one unit to the next.

As stated hereinbefore, a single hose second-stage regulator also controls the exhaustion of gases from the system during exhalation by the diver. Preferably, exhalation should be no more difficult or time consuming under water than at the surface. This requires relatively large exhaust ports and passageways, and check valves are ordinarily provided therein to permit the flow of the exhaust gases into the surrounding water but to prevent the flow of water into the system when exhalation ceases. The latter function requires the use of a rapidly responding check valve, and the prior art exhaust systems have been a compromise between acceptable exhalation flow rates and acceptable check valve closing time with the result that neither has been entirely satisfactory.

Finally, the most important characteristic of all SCUBA equipment is reliability, and reliability is generally related to simplicity. Over the years, this equipment has, therefore, been simplified not only to improve the reliability factor but also to facilitate maintenance and repair thereof. Nevertheless, there remains a yet unattained simplicity of design which absolutely minimizes the number of moving parts in the system.

The objects of this invention are to provide a regulator having fewer moving parts and which is thus simpler to build and maintain than the prior art regulators, a regulator requiring substantially less exhalation effort on the part of the diver and a regulator which enables greater control of the amount of inhalation effort required to open the control valve to admit air to the diver.

The above and further objects and a better understanding of the present invention may be had by reference to the following detailed description taken in connection with the accompanying drawings, wherein:

FIG. 1 is an elevational view of a regulator embodying the present invention;

FIG. 2 is an elevational view taken from the side of the regulator of FIG. 1;

FIG. 3 is a greatly enlarged sectional view taken along the line 3--3 of FIG. 1;

FIG. 4 is an enlarged view looking along the line 4--4 of FIG. 2 with the cover portion of the regulator removed;

FIG. 5 is an enlarged sectional view showing the valve and associated actuator level in a valve open position;

FIG. 6 is a view similar to FIG. 5 showing the valve-actuating lever and the valve in a closed position; and

FIG. 7 is a partial sectional view taken along line 7--7 of FIG. 4.

Referring to the drawings and particularly to FIGS. 1 and 2 thereof, there is shown a pressure regulator 10 comprising a generally cup-shaped housing member 11 over which is positioned a cover 12 held in place on the housing 11 by a retaining ring 14. An air inlet fitting 16 extends through the sidewall of the housing and opens into the chamber 17 (FIG. 3) within the housing 11. A mouthpiece (not shown) which fits into the diver's mouth connects to a mouthpiece tube 18 through which air is controllably fed from the regulator to the lungs of the diver. During exhalation the diver breathes back into the chamber 17 through the mouthpiece tube 18 and these exhausted gases exit the chamber 11 through exhaust valves 19 and 20 (FIG. 4) into an elongated exhaust manifold 21 having a pair of exhaust ports respectively disposed at the ends 22 and 24 thereof.

Referring now to FIGS. 3 and 4 for a more detailed understanding of the present invention, a generally circular, flexible diaphragm 26 having an enlarged peripheral flange portion 28 rests in an annular rabbet 30 integrally formed in the peripheral upper edge of the housing 11. A convex radius 32 of the annular peripheral edge of the cover 12 rests on the top of the diaphragm flange 28 whereby the flange 28 is sandwiched between the radius 32 and the horizontal portion of the rabbet 30. The retaining ring 14 has an annular web portion 34 and a pair of diverging flange portions 36 and 38. As best shown in FIG. 2, the retaining ring 14 is split at 40 and a pair of bushing sleeves 42 and 44 are respectively welded to the ring on opposite sides of the split 40.

The bushing 44 is internally threaded and a setscrew 46 extends through a counterbore in the bushing 42 into threaded engagement with the bushing 44 so that as the screw 46 is tightened the ring 14 is compressed. Consequently, the flanges 36 and 38 respectively engage the distal edge of the cover 12 and the bottom corner of the rabbet portion 30 of the housing 11 to force the radius portion 32 of the cover 12 toward the housing 11 thereby to sealably compress the flange 28 therebetween to hermetically seal the diaphragm 26 across the chamber 17 in the housing 11. The diaphragm 26 is molded of a suitable flexible and resilient material such as rubber and includes an annular radius portion 50 disposed between the flange 28 and a cylindrical portion 54. A circular central portion 56 extends parallel to the flange 28 of the diaphragm in substantially spaced planar relationship therefrom and an inwardly extending annular flange portion 58 defines an annular groove 60 in which a rigid circular disc 62, conveniently formed of metal, is mounted.

The radius 50 is relatively large when the diaphragm 26 is in the illustrated position. As, however, the central portion 56 of the diaphragm moves downwardly into the chamber 17, the radius 50 shrinks and moves toward the center of the diaphragm. This diaphragm construction wherein the outer annular portion thereof is very flexible and thus has a concave upper surface results in a system in which the effective area of the diaphragm remains substantially constant throughout the normal range of movement thereof.

A generally cylindrical recess 64 is centrally disposed in the cover 12 to accommodate a purge button 66 having a shank portion 68 slidably extending through a centrally disposed aperture 70 in the cover 12. A washer 72 is secured to the purge button 66 to maintain it in assembled relationship with respect to the cover 12. A spring 71 is mounted in the recess 64 and holds the purge button 66 in an upward inoperative position as shown. As shown in FIG. 3, the lower end 74 of the purge button 66 abuts an integral, hemispherical protuberance 71 centrally located on the upper surface of the diaphragm 26.

A plurality of slots are provided in the cover at 76 in the cover 12 to admit water from the ambient to the upper surface of the diaphragm 26 whereby the pressure on the upper surface of the diaphragm 26 is equal to that of the ambient.

A tubular inlet valve housing and orifice member 80 extends through a circular opening 82 in the upstanding cylindrical sidewall of the housing 11 and is welded or brazed thereto to provide a seal between the housing 11 and the housing tube 80. The portion of the valve housing 80 which extends exteriorly of the housing 11 is provided with an internal thread 84 which threadedly receives a fitting 86 to which a suitable flexible tube (not shown) is attached for connection to the outlet of a first stage regulator. The fitting 86 has an annular recess 88 near its inner end for receiving an O-ring 90 which is compressed between the inner wall of the valve housing 80 and the fitting 86 to provide an airtight seal between the members.

The fitting 86 is provided with an axial bore 92 and a frustoconical valve seat 94 surrounding such bore at the inner end thereof. A valve member 98 is slidably mounted within the housing tube 80 and has a stem or shank portion 100 which is square in cross section at the end thereof and extends through a square aperture 102 in the end wall 103 of the housing tube 80. The aperture 102 being square in cross section loosely receives the square-ended shank portion 100 of the valve member 98 but prevents relative rotation of the valve member 98 in the housing tube 80. An integral flange 104 provided on the valve member 98 is also substantially square in cross section and a coil spring 106 is compressed between the flange 104 and the end wall 103 of the valve housing 80 to urge the valve member 98 toward the valve seat 94.

Another flange 110 is provided on the valve member 98, is also square in cross section, and is spaced from the flange 104. A resilient valve surface in the form of a rubber disc 112 is cemented on the outer end of the valve member 98 for seating against the valve seat 94 under the force exerted on the valve member 98 by the spring 106. The flanges 104 and 110 each have chamfered corners and diagonal dimensions slightly less than the internal diameter of the housing tube 80.

In order to control the opening and closing of the inlet valve in response to the pressure differential between the chamber 17 and the pressure acting on the upper surface of the diaphragm 26, a valve-actuating lever 116 is interconnected between the valve 98 and the plate portion 62 of the diaphragm 26. As best shown in FIGS. 3 and 4, the lever 116 is an integral member suitably formed of wire which includes a pair of one-turn coil portions 118 and 119 spaced apart by a straight, horizontally extending portion 120. A pair of arm portions 121 and 122, respectively extend from the coil portions 118 and 119, and terminate in a pair of aligned sections 124 and 126. The ends of the sections 124 and 126 are flattened at 125 and 127 respectively, as best shown in FIG. 4, and respectively extend through rectangular openings 128 and 130 in the valve housing tube 80 into the space between the flanges 104 and 110 on the valve member 98. The flats 125 and 127 at the ends of the lever 116 are so oriented with respect to the plane of the arms 121 and 122 that they lie in a vertical position against the left-hand sides (as viewed in FIG. 4) of the rectangular openings 128 and 130 when the valve is in a fully closed position with the coil portions 118 and 119 of the lever 116 abutting the under-surface of the plate 62 of the diaphragm 26. This condition is best shown in FIG. 6 where it can be seen that the lever is held in this position by the spring 106 acting through the flange 104 on the valve member. When the diaphragm 26 moves downwardly into the chamber 48, the lever 116 is pivoted in a clockwise direction as viewed in FIG. 3, whereby the flats 125 and 127 at the ends of the lever pivot about the lower left-hand corner of the openings 128 and 130 as shown in FIG. 3 and the upper edges of the flats move against the leftward face of the flange 104 to move the valve member 98 toward the right against the force of the spring 106 thereby to open the valve. As air enters the valve housing 80, it passes through the spaces provided between the flats on the flanges 104 and 110 and the inner wall of the housing tube 80 and passes into the chamber 17 through an orifice 134 which is centrally located near the bottom of the chamber 17 directly opposite to the mouthpiece tube port 136 provided in the wall of the housing 11. Because of the relative sizes of the openings 128 and 130 and the orifice 134 and the relative locations thereof, most of the air enters the regulator through the main inlet orifice 134 through there is substantial flow through the openings 128 and 130.

As best shown in FIG. 7, a baffle or deflector plate 138 is positioned in the opening 136 whereby the air from the orifice 135 is directed directly against the upper, curved portion of the baffle 138 from which it is deflected directly down the mouthpiece tube 18 into the mouth of the user. This direct application of air into the mouthpiece permits the mass production of regulators with only a minimum of variation in the rate of airflow per given amount of inhalation force from one unit to the other.

Another feature of the present invention is the provision of dual exhaust ports from the chamber 17. As best shown in FIGS. 4 and 7, the housing 11 is provided with an angular flat portion 140 in which the exhaust ports 19 and 20 are provided. As shown, each of these ports is actually a set of ports, identical in construction. Each of the ports 19 and 20 thus includes three openings spaced apart by three sets of webs 145 connected to a central integral ring portion 148 over which is mounted a pair of flexible disclike valve elements 149 and 150. These resilient flexible check valve elements seat against the outer wall of the housing 11 over the ports 19 and 20 and seal off the chamber 17 from the ambient when the pressure outside of the regulator is greater than that within the chamber 17. They thus prevent leakage of water into the chamber 17.

With regulators of this type it is important that a large exhaust area be provided to reduce the exhalation pressure which must be exerted by the diver in order to exhale. In the past, a single exhaust opening and a single associated check valve have been used for this purpose but the degree to which the exhalation pressure could be reduced was limited by the effectiveness of the check valve to provide a fast responding seal of the opening when the diver stopped exhaling. It has been found that by using a plurality of smaller openings and thus using smaller check valves that rapid response in resealing as well as excellent resealing is achieved. Moreover, the separation of these ports from the inlet orifice 134 by the valve housing 80 eliminates any leakage of air from the system.


Referring particularly to FIGS. 3 and 6, the valve 98 is shown in a closed position against the seat. This condition exists when the diver is not inhaling and the diaphragm is held in its uppermost position against the lower end 74 of the purge button 66. When the diver breathes in, he decreases the pressure within the chamber 17 so that the total force exerted on the diaphragm by the pressure in the chamber 17 and the spring 106 acting through the lever 116 becomes less than the downward force exerted on the diaphragm by the ambient. The diaphragm thus moves down and pivots the lever 116 in a clockwise direction to the position shown in FIG. 5. As the lever 116 pivots, the flat end portions thereof urge the valve member 98 away from the seat 94 whereby air enters the chamber 17 from the orifice 134. Most of this air is deflected directly down the mouthpiece tube 18 to the mouth of the diver. When the diver's lungs are filled, the pressure in the chamber 17 has increased to a sufficient extent to move the diaphragm up to the position shown in FIG. 6 to close the valve. When the diver then exhales, the gases from his lungs pass into the chamber 17 and since the pressure therein thus increases above that of the ambient, these gases are exhausted through the exhaust ports 19 and 20. When the diver stops exhaling, the valves 149 and 150 promptly close to return the regulator to its original condition as shown in FIG. 3.

While the present invention has been described in connection with a particular embodiment thereof, it will be understood that many changes and modifications of this invention may be made by those skilled in the art without departing from the true spirit and scope thereof. Accordingly, the appended claims are intended to cover all such changes and modifications as fall within the true spirit and scope of the present invention.