WO2008059429A2

WO2008059429A2 - Pressure regulator

Info

Publication number: WO2008059429A2
Application number: PCT/IB2007/054584
Authority: WO
Inventors: Rhys James Couzyn
Original assignee: Rhys James Couzyn
Priority date: 2006-11-15
Filing date: 2007-11-12
Publication date: 2008-05-22
Also published as: WO2008059429A3

Abstract

The invention relates to a pressure regulator for use in a breathing apparatus assembly, and more particularly, but not exclusively, to a piston type pressure regulator having a dry ambient chamber. The pressure regulating valve is suitable for use in a diving application and includes a body (20) having a flow passage therethrough and a valve seat (25) located in the flow passage. The valve also includes a valve closure (30) being displaceable between a closed position in which the valve closure1 abuts the valve seat so as to close the flow passage, and an open position in which the valve closure is displaced from the valve seat so as to open the flow passage and biasing means (40) for exerting a bias on the valve closure. The valve is characterized therein that it includes force imparting means (50) adapted to impart a force on the biasing means in order to adjust the bias exerted by the biasing means, the force imparting means being subjected to an ambient pressure in which the pressure regulating valve operates.

Description

PRESSURE REGULATOR

FIELD OF THE INVENTION

The invention relates to a pressure regulator for use in a breathing apparatus assembly, and more particularly, but not exclusively, to a piston type pressure regulator having a dry ambient chamber.

BACKGROUND TO THE INVENTION

Pressure regulators used in diving applications, commonly referred to as diving regulators, are pressure reducing devices used in breathing apparatus assemblies, and supply a diver with breathing gas at ambient pressure from one or more diving cylinders. Pressure reduction is usually performed in two stages. A first stage reduces the pressure from a high pressure to a medium pressure, and a second stage reduces the pressure, on demand, from a medium pressure to ambient pressure.

Two types of first stage regulators are generally used in diving applications, being piston type regulators and diaphragm type regulators. In the piston type first stage, the piston is rigid and acts directly on a seat of the regulator. When the pressure in a medium pressure chamber reduces due to the diver having used gas from the second stage, the piston lifts off the valve seat, thus allowing high pressure gas to flow into the medium pressure chamber until the pressure in the medium pressure chamber has increased sufficiently to push the piston back onto the seat so as to close the valve. A substantial variation in ambient pressure is experienced at different depths, and it is important for the first stage to adjust the medium pressure to a constant pressure differential (approximately 10 bar) above ambient pressure at all times. This is achieved by utilizing an ambient chamber in the first stage, which ambient chamber allows the water pressure to act on the first stage components, and in particular on the piston, so as to increase the medium pressure.

As gas leaves the cylinder and expands in the first stage, the gas cools down rapidly due to adiabatic expansion. It will be appreciated that this may easily result in the water in the ambient chamber freezing, thus preventing the valve in the first stage from closing. Also, if the water in the ambient chamber is dirty or contaminated, it may cause mechanical failure of the first stage valve.

One solution to the above problem is to provide a one-way valve in the ambient chamber, which allows air to escape form the ambient chamber, but not water to enter the chamber. A small amount of air is then continuously bled into the ambient chamber, and when the air pressure in the ambient chamber exceeds the ambient pressure, the one-way valve allows the gas to vent from the ambient chamber without allowing water to enter the chamber. However, this solution has many disadvantages, including high gas wastage as well as a lag in responding to pressure variations. The watertight sealing integrity is also often inadequate, thus resulting in water entering the ambient chamber. OBJECT OF THE INVENTION

It is accordingly an object of this invention to provide a pressure regulator that will, at least partially, alleviate the above disadvantages.

It is a further object of the invention to provide a pressure regulator, which will provide a useful alternative to existing pressure regulators for use in diving applications.

SUMMARY OF THE INVENTION

According to the invention there is provided a pressure regulating valve, suitable for use in a diving application, the valve including: a body having a flow passage therethrough and a valve seat located in the flow passage; a valve closure being displaceable between a closed position in which the valve closure abuts the valve seat so as to close the flow passage, and an open position in which the valve closure is displaced from the valve seat so as to open the flow passage; and biasing means for exerting a bias on the valve closure; the valve being characterized therein that it includes force imparting means adapted to impart a force on the biasing means in order to adjust the bias exerted by the biasing means, the force imparting means being subjected to an ambient pressure in which the pressure regulating valve operates. There is provided for the biasing means to bias the valve closure towards the open position.

The force imparting means may include a pressure plate having two opposing surfaces, a first surface in use being exposed to an ambient environment, and thus the ambient pressure, and a second surface being exposed to an internal chamber of the valve.

There is provided for the pressure plate to seal the internal chamber from the ambient environment.

The pressure plate is preferably in the form of a diaphragm, and may be disc-shaped or annular when viewed in plan.

The force imparting means may also include a force transmitting member for transmitting a force exerted on the pressure plate to the biasing means being located inside the internal chamber of the valve. Alternatively, the biasing means may be located between the pressure plate and the force transmitting means, wherein the force transmitting means transmits a force from the biasing means to the valve closure inside the internal chamber of the valve.

There is provided for the internal chamber to be a dry chamber that is sealed from the environment in which the valve operates.

There is provided for the force transmitting means to be in the form of a first pedestal- like member, having a circular base and at least one leg extending from the base. The pressure plate may be arranged to abut the base of the force transmitting means, so as to in use be able to impart a force on the base.

The force transmitting means may also include a second pedestal-like member, having a circular base and at least one leg extending from the base. The first and the second pedestal-like members may be configured in order for ends of the legs of the first and second pedestal-like members to abut.

The second pedestal-like member may be located inside the internal chamber of the valve, and the base of the second pedestal-like member may abut the biasing means.

The legs of the first and second pedestal-like members may extend through transmission passages provided in the body of the valve.

The valve closure may be in the form of a piston arrangement including a circular disc and a tubular stem extending therefrom, the end of the stem abutting the seat of the valve when the closure member is in the closed position.

The flow passage may include an inlet port and an outlet port, and may extend through the hollow tubular stem of the piston-like valve closure.

The biasing mean may be in the form of a helical spring, and may abut a first side of the disc of the valve closure. A second side of the disc of the valve closure may be in fluid communication with the flow passage, and more particularly with a medium pressure chamber of the valve.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described by way of non-limiting examples, and with reference to the accompanying drawings in which:

Figure 1 shows a perspective view of an assembled pressure-regulating valve in accordance with the invention;

Figure 2 shows an exploded perspective view of the valve of figure 1 ;

Figure 3 shows a partially cut-away view of part of the valve of figure 2;

Figure 4 shows a cross-sectional side view of the valve of figure 1 ;

Figure 5 shows a partially exploded perspective view of a further embodiment of the invention;

Figure 6 shows a partially exploded perspective view of a further embodiment of the invention;

Figure 7 shows a partially exploded perspective view of another embodiment of the invention; and Figure 8 shows a partially exploded perspective view of a still further embodiment of the invention.

DETAIL DESCRIPTION OF THE INVENTION

Referring to the drawings in which like numerals indicate like features, a non-limiting example of a pressure-regulating valve in accordance with the invention is indicated by reference numeral 10. The pressure-regulating valve 10 is suitable for use as a diving regulator where the ambient environment 15 will be water, as in use the pressure- regulating valve 10 will be submerged. The pressure-regulating valve 10 includes a valve body 20, a valve closure 30, a biasing means 40 as well as a force imparting means 50.

A first embodiment of the invention is shown in Figures 1 to 4. Figure 1 shows a pressure regulating valve 10 in an assembled condition, including a valve body 20 having an inlet 21 and at least one outlet 23. An inlet fitting 22 in the form of a DIN or a yoke fitting is provided for securing an outlet connection from a gas cylinder (not shown) to the valve body 20. The valve 10 also includes an end cap 27, which is secured to the valve body 20 by way of a threaded arrangement. At least one auxiliary outlet 24 is also provided, which outlet is in flow-communication with the high-pressure gas flowing into the valve 20.

An exploded view of the valve of Figure 1 is shown in Figure 2, and the internal components of the valve 20 are shown in more detail. The valve includes a valve closure 30 that comprises a disc 31 as well as a tubular stem 32, the tubular stem being hollow and forming part of the flow passage as described in more detail hereinbelow. The tubular stem terminates in a knife-edge 33, which abuts a seat provided in the flow passage. Biasing means 40 in the form of a helical spring is provided, and includes a first end 41 and a second end 42. A first end 41 of the biasing means abuts a first side 31.1 of the disc 31, whereas a second end 42 of the biasing means 40 abuts a component of the force imparting means 50 as is described hereinbelow.

The force imparting means 50 comprises a plurality of components including a pressure plate 51 , a first force-transmitting member 55 and a second force-transmitting member 56. The pressure plate 51 is typically in the form of a diaphragm. The pressure plate 51 has a first surface 51.1 which is exposed to the ambient environment 15, as well as a second surface 51.2 which is exposed to an internal chamber 29 located inside the valve body 20. The pressure plate 51 is retained in position by way of a retaining mechanism 52, and the pressure plate 51 so retained forms a seal between the ambient environment 15 and the internal chamber 29. An outer cap 53 may also be provided, and will overlie both the pressure plate 51 and the retaining mechanism 52. The outer cap 53 however includes a plurality of apertures 54 to ensure that the pressure plate 51 remains in flow communication with the ambient environment 15.

A first force transmitting member 55 is located adjacent the pressure plate 51 , and is in the form of a pedestal-like member having a base 55.1 and a plurality of legs 55.2, in this embodiment three, extending therefrom. When the pressure plate 51 is displaced due to a change in ambient pressure in the ambient environment 15, the force imparted on the pressure plate 51 is exerted on the base 55.1 of the first force-transmitting member 55. Such force is then transmitted via the legs 55.2 of the first force- transmitting member 55 to legs 56.2 and thus a base 56.1 of the second force- transmitting member 56. The second force-transmitting member 56 subsequently transmits such force to a second end 42 of the biasing means 40, thus effectively compressing the biasing means and increasing the bias exerted by the biasing means on the valve closure 30. Transmission passages 29.1 , as is best seen in Figure 3, are provided in the body 20 of the valve 10 and allows displacement of the first force transmitting member 55 and the second force transmitting member 56 when the pressure plate 51 is displaced.

As can be best seen in Figure 4, the biasing means is located inside an internal chamber 29 which is not in flow communication with any one of the high pressure chamber 28.1 of the valve 20, the medium pressure chamber 28.2 of the valve 20 or the ambient environment 15. The internal chamber 29 is sealed from the ambient environment 15 by means of the pressure plate 51.

The valve closure 30 is displaceable between a closed position wherein the knife-edged end 33 of the tubular stem 32 abuts a seat 25 provided in the valve body 20, and an open position wherein the knife-edged end 33 is displaced from the seat 25. A flow passage is defined from the inlet 21 to the high-pressure chamber 28.1 , into the hollow tubular stem 32, and into a medium pressure chamber 28.2. The flow passage is indicated by arrow A. The valve closure 30 is biased towards the open position. In use, high-pressure gas will enter the valve body 20 through the inlet 21 , and will flow through the hollow tubular stem 32 into the medium pressure chamber 28.2. As the pressure in the medium pressure chamber 28.2 increases, a force imparted on the second side 31.2 of the disc 31 of the valve closure 30 increases, thus counter-acting the biasing means 40 and displacing the valve closure 30 to a closed position. Once the pressure in the medium pressure chamber 28.2 has been reduced due to demand from a user, the force exerted by the biasing means 40 will again exceed the closing force exerted on the second side 31.2 of the disc 31 , and the valve will open so as to allow high-pressure gas to enter the medium pressure chamber 28.2.

Upon an increase in the pressure of the ambient environment 15, for instance when a diver descends into the water, the force exerted on the pressure plate 51 will increase, thus causing the pressure plate to be displaced in the direction of arrow B. This displacement, and thus the force, is transmitted to the first force-transmitting member 55, which in turn transmits the displacement, and this force, to the second force transmitting member 56. The second end 42of the biasing means 40 is subsequently displaced, thus causing the effective length of the biasing means (indicated by arrow C) to be reduced, and the force exerted by the biasing means 40 to be proportionally increased. This increase in bias ensures that the pressure differential in the medium pressure chamber 28.2 remains constant at all times. However, the internal chamber 29 is never exposed to water from the ambient environment 15, and there will therefore not be a risk of freezing of water in the internal chamber 29 due to adiabatic expansion.

It will be appreciated that the same concept, that is, ambient pressure compensation in a piston-type pressure-regulating valve 10 whilst maintaining a dry chamber, can be used in many different configurations, without departing from the spirit and/or the scope of the invention. Figure 5 shows a further embodiment of this invention when the pressure plate 51 as well as the retaining mechanism 52 is of annular configuration, which allows the seat retainer 26 to be accessible when the outer cap 53 is removed. Figure 6 shows a further embodiment of the invention, as used in an un-balanced valve, wherein the inlet of the valve is not located at the side of the valve body 20, but at one end thereof. In this case, the pressure plate 51 as well as the retaining mechanism 52 is of annular configuration, and the inlet 21 is located in the center of the annulus. Again, a plurality of apertures 54 is provided in the retaining member 52 to ensure that the pressure plate 51 is in flow communication with the ambient environment 15.

Figure 7 shows a further embodiment of the invention where the inventive concept is also used in combination with an un-balanced valve. Again a pressure plate 51 is provided and exerts a force on the first force-transmitting member 55. A retaining mechanism 52, which also serves as outer cap, is provided and includes a plurality of apertures 54.

A still further embodiment is shown in Figure 8. In this embodiment, the biasing means 40 is located between the pressure plate 51 and the first force-transmitting member 55. The pressure plate 51, through an intermediate force transmitting disc 75, exerts a force on the biasing means 40, and the force exerted by the biasing means 40, is transmitted to the valve closure by way of the first force-transmitting member 55 and the second force-transmitting member 56. Although the order of components has been inverted, the net effect is still for the biasing means to be displaced due to a change in ambient conditions, without the biasing means actually being in contact with the fluid that constitutes the ambient environment. This embodiment also includes a spring screw 70, which is adjustable from the outside in order to adjust the spring force.

All the above embodiments share the common denominator that the force exerted by the biasing means 40 is automatically adjusted when the ambient pressure of the environment changes, due to a compensating force that is exerted by the pressure plate on the force transmitting members and thus the biasing means. The ambient pressure thus indirectly acts on the biasing means. However, the internal chamber in which the biasing means is located remains dry at all times and is not exposed to the water. The inventor believes that this is a major improvement, as the risk of freezing or damage due to dirty or contaminated water in the internal chamber is negated.

It will be appreciated that the above are only some embodiments of the invention and that there may be many changes without departing from the spirit and the scope of the invention. This specific design of the force transmitting members is for instance not important, as the particular arrangement will be dictated by the layout of the valve body 20. Likewise, the arrangement of the valve body 20 is not limiting, provided that there is a flow passage from a high-pressure chamber towards a medium-pressure chamber, and a biasing means that exerts a bias on a valve closure opening and closing the flow passage.

Claims

CLAIMS:

1. A pressure regulating valve, suitable for use in a diving application, the valve including: a body having a flow passage therethrough and a valve seat located in the flow passage; a valve closure being displaceable between a closed position in which the valve closure abuts the valve seat so as to close the flow passage, and an open position in which the valve closure is displaced from the valve seat so as to open the flow passage; and biasing means for exerting a bias on the valve closure; the valve being characterized therein that it includes force imparting means adapted to impart a force on the biasing means in order to adjust the bias exerted by the biasing means, the force imparting means being exposed to an ambient pressure in which the pressure regulating valve operates.

2. The pressure regulating valve of claim 1 wherein the biasing means bias the valve closure towards the open position.

3. The pressure regulating valve of claim 1 or claim 2 wherein the force imparting means includes a pressure plate having two opposing surfaces, a first surface in use being exposed to an ambient pressure, and an opposite second surface being exposed to an internal chamber of the valve.

4. The pressure regulating valve of claim 3 wherein the pressure plate forms a seal between the internal chamber and the ambient environment.

5. The pressure regulating valve of claim 3 or claim 4 wherein the pressure plate is in the form of a circular diaphragm.

6. The pressure regulating valve of claim 5 wherein the pressure plate is annular when viewed in plan.

7. The pressure regulating valve of any one of the preceding claims wherein the force imparting means include a force transmitting member for transmitting a force resulting from the ambient pressure to the biasing means located inside the internal chamber of the valve.

8. The pressure regulating valve of any one of claims 3 to 6 wherein the force imparting means include a force transmitting member for transmitting a force exerted on the pressure plate to the biasing means located inside the internal chamber of the valve.

9. The pressure regulating valve of any one of claims 3 to 6 wherein the biasing means is located between the pressure plate and a force transmitting member, wherein the force transmitting member transmits a force from the biasing means to the valve closure inside the internal chamber of the valve.

10. The pressure regulating valve of any one of claims 3 to 9 wherein the internal chamber is a dry chamber that is sealed from the environment in which the valve operates.

11. The pressure regulating valve of any one of claims 7 to 10 wherein the force transmitting member includes a first pedestal-like member, having a circular base and at least one leg extending from the base.

12. The pressure regulating valve of claim 11 wherein the pressure plate is arranged to abut the base of the force transmitting means, so as to in use be able to impart a force on the base.

13. The pressure regulating valve of any one of claims 7 to 12 wherein the force transmitting member includes a second pedestal-like member, having a circular base and at least one leg extending from the base.

14. The pressure regulating valve of claim 13 wherein the first and the second pedestal-like members are configured in order for ends of the legs of the first and second pedestal-like members to abut.

15. The pressure regulating valve of claim 13 or claim 14 wherein the second pedestal-like member is located inside the internal chamber of the valve, and the base of the second pedestal-like member abuts the biasing means.

16. The pressure regulating valve of any one of claims 13 to 15 wherein the legs of the first and second pedestal-like members extend through transmission passages provided in the body of the valve.

17. The pressure regulating valve of any one of the preceding claims wherein the valve closure is in the form of a piston arrangement including a circular disc and a tubular stem extending therefrom, the end of the stem abutting the seat of the valve when the closure member is in the closed position.

18. The pressure regulating valve of claim 17 wherein the flow passage passes through the hollow tubular stem of the piston-like valve closure.

19. The pressure regulating valve of claim 17 or claim 18 wherein the biasing mean is in the form of a helical spring that abuts a first side of the disc of the valve closure.

20. The pressure regulating valve of any one of claims 17 to 19 wherein a second side of the disc of the valve closure is in fluid communication with the flow passage.