Pressure regulating device

Abstract

A first stage regulator for two-stage delivering assemblies includes a first chamber connected through an inlet to a high pressure gas source; a second chamber for the breathable gas at an intermediate pressure, which is connected to a user; a pressure reducing valve connecting the first and the second chambers and having a valve seat and a cut-off that cooperates with the valve seat and is displaceable from a closed position to an open position thereof and vice versa. The cut-off is dynamically connected to a sensor exposed to the external pressure and includes a transmitting element of the mechanical stress exerted on the sensor by the external pressure. The sensor includes a movable wall that is sealingly slidable in a housing chamber and constitutes the interface wall towards the outside, and the transmitting mechanism connects the movable wall with the cut-off.

Claims

1. A first stage regulator for two-stage delivering assemblies, comprising: a first chamber for a breathable high pressure gas, the first chamber being adapted to be connected through an inlet to a high pressure breathable gas source; a second chamber for the breathable gas at an intermediate pressure, the second chamber having an outlet for the breathable gas and being adapted to be connected to a user of said breathable gas; and a pressure reducing valve which connects said first chamber and said second chamber with each other, the pressure reducing valve comprising a valve seat having a passage opening for communication between said first and said second chambers and a cut-off cooperating with said valve seat and displaceable from a closed position of said passage opening to an open position of said passage opening and vice versa, said cut-off being dynamically connected to a sensor exposed to the a pressure of an external environment of said first and said second chambers, the sensor comprising a transmitting mechanism adapted to transmit a mechanical stress exerted on said sensor by the pressure of the external environment of the cut-off, wherein said sensor comprises a rigid element of a movable wall which is sealingly slidable in a housing chamber, and which provides an interface wall of said housing chamber towards the external environment, and wherein said transmitting mechanism connects said movable wall with said cut-off.

2. The first stage regulator according to claim 1, wherein said sensor and said housing chamber are of a cylinder/plunger type.

3. The first stage regulator according to claim 1, wherein the sensor is formed by a plunger and provides a movable base of the housing chamber formed by a cylinder, said sensor being displaced inside said cylinder in parallel and along a direction of a cylinder axis, said cylinder axis being at least parallel or coaxial to a displacement direction of the cut-off between said two opening and closing positions of the opening of the valve seat, the transmission members being a rod connecting the sensor with the cut-off.

4. The first stage regulator according to claim 1, wherein an axis of the passage opening of the valve seat is coincident with or parallel to an axis of a cylinder forming the housing chamber of the sensor, while the cut-off is a sealing element mounted on a piston sliding in a cylindrical seat, the piston and the seat being parallel to or coincident with said axis of the passage opening of the valve seat and/or with the axis of the cylinder forming the housing chamber of the sensor.

5. The first stage regulator according to claim 1, wherein the cut-off is combined with an elastic pre-loading element.

6. The first stage regulator according to claim 5, wherein an elastic pre-loading element is combined with the sensor too.

7. The first stage regulator according to claim 1, wherein the sensor sensing the external environment pressure comprises two movable wall elements which are spaced apart from each other due to mutual connecting means in parallel with a sliding direction, one of said movable wall elements providing an interface with the external environment and the other one providing an interface between the housing chamber of said two movable wall elements towards the second chamber and both sealingly delimiting, respectively towards the external environment and towards the second chamber, an interposition chamber which is insulated from the external environment and from the second chamber and which consists of a housing chamber portion having variable position and whose extent, in the sliding direction of the two movable wall elements, corresponds to a distance between said two movable wall elements.

8. The first stage regulator according to claim 7, wherein a fluid in the interposition chamber has a pressure set at a preset value and substantially invariable with respect to pressure conditions of the external environment and of the high-pressure and intermediate-pressure chambers.

9. The first stage regulator according to claim 7, wherein the two movable wall elements are rigidly connected to each other.

10. The first stage regulator according to claim 7, wherein each of the two movable walls is shaped as a plunger housed in a housing chamber acting as a cylinder, both plungers being sealingly guided along walls of the cylinders due to peripheral sealing gaskets.

11. The first stage regulator according to claim 10, wherein both of said movable wall elements are arranged to be displaced inside said cylinder in parallel and in a displacement direction of a cylinder axis, said cylinder axis being at least parallel or coaxial to the displacement direction of the cut-off between said two opening and closing positions of the passage opening of the valve seat, the transmission members being constituted by a rod connecting the sensor with the cut-off.

12. The first stage regulator according to claim 11, wherein an axis of the passage opening of the valve seat is coincident with or parallel to an axis of a cylinder forming the housing chamber of the sensor, the cut-off being a sealing element mounted on a piston sliding in a cylindrical seat, the piston and the seat, being parallel to or coincident with said axis of the passage opening of the valve seat and/or with the axis of the cylinder forming the housing chamber of the two movable wall elements.

13. The first stage regulator according to claim 11, wherein the first chamber, the second chamber, the housing chamber, the pressure reducing valve seat and/or the passage opening in said seat, the piston-shaped cut-off and a guiding seat thereof, the two movable walls of the sensor, the connecting rod between said sensor and piston-shaped cut-off, all have a rotational symmetry and are coaxial with each other.

14. The first stage regulator according to claim 7, wherein the cut-off is combined with an elastic pre-loading element.

15. The first stage regulator according to claim 7, further comprising an elastic pre-loading element combined with the sensor, said elastic pre-loading element being positioned inside the interposition chamber delimited by the two movable wall elements.

16. The first stage regulator according to claim 15, wherein the elastic element acts on an element of movable wall interfacing towards the second chamber on a face of the element of the movable wall inside the interposition chamber, a stationary limit stop for said elastic pre-loading element being also arranged inside said interposition chamber and adapted to be fixed in a stable position in said interposition chamber, the stationary limit stop being provided with a passage opening for a rod connecting the two movable walls with each other.

17. The first stage regulator according to claim 7, wherein between the movable wall element forming the interface towards the external environment and said external environment there is a flexible membrane sealingly mounted at an end of the cylindrical housing chamber of said movable wall element.

18. The first stage regulator according to claim 17, wherein the movable wall element providing the interface towards the external environment has no sliding sealing gaskets cooperating with a housing wall and is free to slide being guided along said housing wall without friction interference.

Description

[0079] Further advantages and characteristics of the device according to the present invention will become clearer in the following detailed description of an embodiment thereof, made by way of example and without limitations, with reference to the accompanying tables of drawings, in which:

[0080] FIG. 1 shows a sectional view according to a plane passing through the symmetry axis parallel to the displacement direction of the pressure reducing valve cut-off and which view is relative to a first embodiment of the known art which uses a membrane.

[0081] FIG. 2 shows a sectional view according to a plane passing through the symmetry axis parallel to the displacement direction of the pressure reducing valve cut-off and which view is relative to a second embodiment of the known art corresponding to a so-named first piston stage.

[0082] FIG. 3 shows a sectional view according to a plane passing through the symmetry axis parallel to the displacement direction of the pressure reducing valve cut-off and which view is relative to a third embodiment of the known art.

[0083] FIG. 4 shows, similarly to the preceding figures, a further embodiment according to the state of the art.

[0084] FIG. 5 shows an embodiment variant of the embodiment of the state of the art according to FIG. 4.

[0085] FIG. 6 shows a view similar to that of the preceding figures of a first embodiment of the invention which consists in the improvement of the first embodiment according to the known art shown in FIG. 1.

[0086] FIG. 7 shows, similarly to FIG. 5, a second embodiment of the invention which consists in the improvement of the third embodiment according to the known art shown in FIG. 5.

[0087] The first and second embodiments of the present invention shown in FIGS. 6 and 7 comprise a combination of all the characteristics provided therefor and refer to a preferred configuration which must not however be considered limiting with respect to the combinations of characteristics denoted in the various embodiment variants in the introduction of the present description. For example, FIG. 7 shows a membrane 212 which does not constitute an essential characteristic of the device and which can thus be missing in an embodiment of the invention. Similarly, the selection of a configuration of rotational symmetry of the device is a preferred choice, but it must not be understood as a limiting form. Also the use of coil springs as elastic pre-loading means, and the particular solution of the corresponding parts regulatable by screwing to modify the pre-loading force, is a preferred solution, but it must not be understood as limiting.

[0088] FIG. 6 shows a first embodiment of the regulator first stage according to the present invention; 1 denotes the body of said first stage, which has a high pressure chamber 101 provided with a plurality of inlets 511 to which a high pressure breathable gas source is connected, not shown in the figure and known as a high pressure breathable gas supply cylinder. The reducing valve seat 301, which leads into the intermediate pressure chamber 201, and whose flow is regulated by the cut-off 311, is placed in the chamber 101. The cut-off 311 is connected to a stem 321, which ends on the opposite end, inside the chamber 201, with a disc 331. The intermediate pressure chamber 201 is provided with a plurality of outlets denoted by 211 in the figure.

[0089] At the top of the intermediate pressure chamber 201, a threaded opening 401, in which the sealing lock 2 is screwed thanks to the gasket 411, is formed in the body 1 of the first stage. A cylindrical chamber 102 housing a movable wall element 402 is formed in the lock 2. The movable wall element 402 according to this preferred embodiment has a rotational symmetry and is in the form of circular plunger which is displaceable in the direction of its axis inside a ground length 112 inside the cylindrical chamber 102. The movable wall element 402 sealingly slides, thanks to an annular peripheral gasket 422, along the ground cylindrical wall 112. The travel is limited at least on one side by a limit stop 130. The end opposite to the travel is delimited by the abutment position of the cut-off against a limit stop inside the high pressure chamber. The two travel limit positions are axially spaced apart from each other, i.e. spaced apart in the displacement direction of the movable wall element 402. The gasket 422 is inserted in a toroidal throat 412 provided in the shell edge of the movable wall element 402.

[0090] An annular groove 432 is formed on a face of the movable wall element 402; such groove is intended to cooperate with a pre-loading coil spring 312. A ferrule 302, which is screwed to the lock 2, inside the chamber 102 at a given axial distance from the movable wall element 402, constitutes the stationary limit stop against which abuts the end of the coil spring 312 opposite the one leaning against the movable wall element 402.

[0091] The rod 321 rigidly connecting the movable wall element 402 to the cut-off 311 passes through coaxial holes of the cut-off 311 itself, which form the travel limit stop of the plunger in the cylindrical chamber 102 in which said plunger 402 is housed. Advantageously, the rod 321 is not mechanically connected to the movable wall element but rests against it, optionally and preferably thanks to a terminal disc 331.

[0092] According to a further characteristic, a bushing 452 departs on the side of the movable wall element 422 facing the external environment, i.e. opposite to the intermediate pressure chamber 201, in a position coaxial to said movable wall element 422 which, in the embodiment, is in the form of a cylindrical plunger. This bushing has a diameter identical to or slightly less than the diameter inside the coil spring 312 which is slipped above it. Said bushing has a central hole 462 which conically widens 472 towards the end opposite to the one connecting to the movable wall element 402.

[0093] In an embodiment, the conical length can extend over the whole thickness of the wall of the bushing 462.

[0094] The operation of the regulator first stage according to the present invention will become clearer hereunder. On the basis of the problems highlighted in the state of the art, in the solution suggested according to the embodiment of FIG. 6, it was intended to replace a flexible wall, such as that of the membrane 11 shown in FIG. 1, with a system for transmitting the pressure variations inside the intermediate pressure chamber, dependent on breathing cycles and on the pressure variations of the environment outside of the device, which is not easily subject to wear of the mechanical type and which is simultaneously able to react just as efficiently.

[0095] Preferably, the movable wall element 402 in its embodiment as a plunger that is sealingly and slidingly inserted in the appropriately rectified seat 112 is able to transfer, substantially without inertia, the pressure variation of the external environment perceived by the movable wall element 402 itself inserted in the seat 112. The behavior of the movable wall, here constituted in the form of plunger 402, is even more effective than that of the membrane which, by nature, tends to bend in an uneven manner, whereas the plunger, which slides with respect to the seat in which it is positioned, offers its whole surface to the fluid with which it is in contact.

[0096] The solution of the embodiment according to FIG. 6 thus overcomes the problems of the know art in terms of mechanical robustness, thus preventing the risk of malfunctions due to the breakage of the membrane in the devices of the known art. Moreover, it accurately defines the surface exposed to the external environment pressure transferring it to the cut-off, since the extension of the active surface on which the pressure acts is accurately delimited and thus the pressure is transformed with as much accuracy into a force, whereas in the devices of the known art, the active surface defined by calculating the force caused by the external environment pressure is subject to being inaccurate due to the deformations of the membrane in the peripheral areas thereof.

[0097] FIG. 7 shows a second embodiment which constitutes the improvement according to the invention of a regulator first stage according to the configuration of the known art shown in FIG. 5.

[0098] The same reference numbers as those used in FIG. 6 will be used in FIG. 7 for identical parts or having the same function.

[0099] 1 denotes the body of said first stage, which has a high pressure chamber 101 provided with a plurality of high pressure outlets, for example for connecting pressure gauges or other utilities, and is connected, in a known manner not shown in the figures, to the high pressure breathable gas supply cylinder. The reducing valve seat 301, which leads into the intermediate pressure chamber 201 and which flow is regulated by the cut-off 311, is placed in the chamber. Also in this embodiment, the cut-off is coupled to the stem 321, which ends on the opposite end inside the chamber 201, with a disc 331. The intermediate pressure chamber is provided with a plurality of outlets 211.

[0100] At the top of the intermediate pressure chamber 201, a threaded opening 401, in which the sealing lock 2 is screwed thanks to the gasket 411, is formed in the body 1 of the first stage. A cylindrical housing chamber 102 of a sensor member of the external environment pressure is formed inside the lock 2.

[0101] Said chamber 102 is provided with two ground cylindrical seats 112 and 122, respectively facing the intermediate pressure chamber 201 and the external environment and separated by a threaded length in which a stop ferrule 302 for an elastic pre-loading coil spring 312 of the sensor member of the external environment pressure is screwed.

[0102] A plunger-shaped movable wall element 402 is respectively inserted inside both seats 112, 122. The two movable wall elements shown in FIG. 7 are identical to one another, in particular with respect to the surface of the two faces perpendicular to the translation direction, i.e. to their central axis.

[0103] Such configuration must not be understood as limiting, but is only a choice among the possible variants in which said movable walls 402 can have different diameters, as described in the introduction of the present description, to affect the variation of the intermediate pressure at the varying of the ambient pressure.

[0104] According to a preferred embodiment, the two movable wall elements 402, i.e. the two plungers, are displaceable together and are couplably connected, respectively having, on sides opposite each other, the movable wall element 402 constituting the separation wall towards the external environment a coupling stem 482, and the second movable wall element 402 interfacing with the intermediate pressure chamber 201 a bushing-shaped engagement seat 452 of said stem axially coinciding with said stem 482, in particular coaxial thereto.

[0105] A preferred embodiment can further provide that the stem has a base portion 492 with which it connects to the corresponding movable wall element 402. This base portion has a diameter greater than a coaxial terminal portion which is intended to be engaged in a hole 462 of the engagement seat 452 and to be locked therein. The axial length of the hole 462 is proportioned with the axial length of said terminal portion of the stem 482.

[0106] According to a further possible characteristic and also as shown, the engagement seat 452 is cylindrical bushing shaped and has an outer diameter corresponding to the outer diameter of said base 492 of the stem 482. The coaxial hole 462 has a diameter corresponding to that of the terminal portion of the stem 482.

[0107] Still according to a characteristic, the base 492 of the stem 482 connects with a length 442 conically tapered to the terminal portion, while the seat 452 has an inlet length 472 which conically narrows from the inserting end towards the bottom of the hole 462, starting from the outer diameter of the bushing forming said engagement seat 452 towards the inner diameter thereof and with an opening angle corresponding to that of the tapered length 442 of the stem 482.

[0108] Still according to a further characteristic, the bushing-shaped engagement seat 452 is combined with the wall element 402, i.e. with the plunger interfacing with the intermediate pressure chamber 201, and constitutes a central supporting element of the elastic element 312, for example a coil spring.

[0109] The rigid integral connection of the two movable wall elements 402, i.e. the two plungers, can occur thanks to removable and/or separable mechanical coupling means which allow to separate the two plungers from each other, i.e. the two movable wall elements.

[0110] With regard to the rigid connection of the two movable wall elements, it is possible to provide other alternative solutions. According to an embodiment variant, the two plunger-shaped movable wall elements 402 are rigidly coupled to each other by means of a pin screwed with the two ends respectively in a threaded cup formed coaxially thereto in the faces of the two movable wall elements 402 facing each other.

[0111] Similarly to the movable wall element of the embodiment according to FIG. 6, also in this embodiment, each plunger 402 of substantially cylindrical shape has a toroidal throat 412 formed on the side surface, in which a sealing element 422 is housed. An annular groove 432, surrounding the engagement seat 452, is formed on a face of the movable wall 402 interfacing with the intermediate pressure chamber 201. The end of a pre-loading spring 312, whose opposite end abuts against the stop ferrule 302 screwed to the lock 2 inside the chamber 102 at an intermediate position in-between the ground cylindrical lengths 112 and 122, is inserted in said annular groove.

[0112] Thanks to this embodiment, an intermediate isolation chamber, which remains sealed both towards the intermediate pressure chamber and the external environment, is generated in the cylindrical chamber 102 of the lock 2 and between the intermediate pressure chamber and the external environment. This isolation chamber translates correspondingly to the translation of the two plungers 402 rigidly connected to each other. The translation of the plungers 402 is delimited in both directions by annular, radial and inner shoulders defining the translation travel limits of which one is constituted by the shoulder 130 cooperating with the plunger 402 interfacing with the intermediate pressure chamber 201 towards the outside, whereas the other is constituted by a limit stop of the cut-off in the high pressure chamber and/or by the head side of the cylindrical chamber 102 cooperating with the disc 331 towards said intermediate pressure chamber.

[0113] It is clear that such ferrule 302 and said coil spring 312 always remain inside the isolation chamber and are thus separated from the external environment and from the intermediate pressure chamber. Moreover, it is clear that the pressure in the isolation chamber can be maintained at a substantially constant desired level. As per the fluid, it is possible to provide different fluids, but ambient air is preferred at the atmospheric pressure automatically generated during the assembly step in the factory.

[0114] However, this does not mean that different types of fluids or mixtures thereof and different pressure conditions in said isolation chamber can't be provided and that possibly said isolation chamber cannot be accessible through an inlet provided with removable sealing means.

[0115] A preferred embodiment provides that the isolation chamber between the two movable wall elements is filled with argon or with a gas mixture containing argon since this inert gas has optimal thermal insulation qualities, thus improving the safety against the formation of ice on the walls of the “upper piston” facing the environment.

[0116] Thus, it is clear that the coil spring and the area in which it is housed remains free from the risk of ice formations and also from the risk of impurity, dirt or other infiltrations that can mechanically limit or completely hamper the operation of the spring.

[0117] Still according to a characteristic shown which is fully optional and which could be omitted, a flexible membrane 212 adhering to the face of the movable wall element 402 facing the external environment and interfacing therewith, is arranged at the end of the lock 2 in which the seat 122 is obtained by means of a threaded ferrule 202. The external environment pressure acts on the movable wall element 402 through said membrane 212 which deforms under the action of said pressure and the membrane is only intended to isolate the chamber 102 only in terms of the fluids circulating which can generate wear or decay effects on the sealing gaskets of the movable wall 402 against the wall of the cylindrical chamber 122 in which it is housed both from a chemical point of view and due to the transport of granules of material.

[0118] The embodiment shown in FIG. 7 is thus a solution that isolates the compensation chamber 102 with respect to the external environment, and the membrane 212 resting directly on the movable wall element, de facto accurately transmits in a determinable precise manner the pressure variations of the environment outside the piston 402, whereas it avoids the direct contact of the external environment fluid with the plunger 402 and the sealing gaskets, protecting them. Advantageously, especially from a productive point of view, relatively to the embodiments shown, the movable wall element 402 interfacing with the intermediate pressure chamber can be identical for both the embodiments, only making it necessary to provide the other movable wall element to make the embodiment of FIG. 7.

[0119] The piston inserted in the seat facing the intermediate pressure chamber is elastically pre-loaded thanks to the spring 312, as occurred for the membrane used at the state of the art. The rigid connection between the two pistons 402 in fact ensures the action of the two movable walls like that of a monolithic entity, which transfers the pressure variations detected in the external environment directly to the rod 321 which operates on the reducing-valve cut-off.

[0120] An embodiment variant of the embodiment according to FIG. 7 can provide that the movable wall element, i.e. the plunger 402 constituting the interface with respect to the external environment and which is in contact with the membrane 212, freely and non-sealingly slides in the cylindrical length 122 and that the seal towards the external environment of the intermediate isolation chamber delimited by the two movable wall elements 402 is entrusted only to the membrane 212 on the side facing the external environment. This reduces the sliding friction and, anyhow, the upper membrane is the less stressed one since it is not exposed to the full pressure difference towards the 10 bars of intermediate pressure.

[0121] In this case, the presence of a constant pressure inside the intermediate isolation chamber allows to limit the pressure difference between the outside and inside of the intermediate chamber and which acts on the membrane 212 itself. Moreover, the membrane 212 rests, almost throughout its whole surface exposed to the external pressure, against the face facing the outside of the movable wall element 402.

[0122] Thus, functionally, the membrane 212 is less mechanically stressed and subjected to breakage due to the wearing of the material and, moreover, the movable wall element 402 on the side interfacing with the intermediate pressure chamber being sealingly slidable in the cylindrical chamber 112, a breakage of the membrane 212 would only involve the flooding of the compartment containing the coil spring and the pre-loading ferrule and thus the drawbacks in the event of dust particle infiltrations, which can degrade the operations of the coil spring 312. However, aside from these drawbacks, the regulator would remain fully operational since the seal of the intermediate pressure chamber towards the external environment and thus against flooding would be ensured by the wall element 402 provided with the sealingly gasket sliding against the cylindrical wall 112.

[0123] With regard to the rigid implementation of the rod connecting the two movable wall elements, such solution is the preferred one shown in FIG. 7, but when desired, the connection between the two plungers 402 can also be made such as to be able to be regulated or elastically shortened or elongated in condition of a preset condition of the ratios between the intermediate pressure and the external environment pressure.

[0124] As is clear in the comparison of the previous description with the known art, it appears that, in the embodiment variant provided with the membrane, the embodiment of FIG. 7 overcomes the drawback of the known art, wherein the action of the external environment pressure, i.e. the water, is exerted directly on the membrane and in turn from it onto the flared heads 20 and 22, thus it doesn't seem more difficult to establish the force ratios transmitted by the rigid element 21. Moreover, the drawback of the known art relative to the fact that in the known art stresses, which lead to a premature breakage of the membrane itself and to the loss of seal with a possible penetration of the environment, i.e. water not only upstream of the second membrane, but also in the event it breaks in the intermediate pressure chamber, are generated in the peripheral sealing tightness area of the membranes, is overcome.

[0125] The device according to the present invention thus solves the problems highlighted with respect to the state of the art with a constructively simple, operatively efficient and reliable solution in terms of safety and resistance to wear.