RELEASE VALVE

Abstract

The invention relates to a release valve (100), installable on a container intended to contain a pressurized fluid and capable of maintaining a pressure difference between a first environment (9) and a second environment (90), comprising a housing (8), a first thrust means (3), a closure element (5), and a slider (2), wherein said housing (8) contains at least said slider (2) and said first thrust means (3), wherein said slider (2) comprises a first surface (25) facing the first environment (9), and a second surface (26), facing the second environment (90), and having an area greater than said first surface (25), wherein said closure element (5) is interposed between said second environment (90) and said slider (2), and wherein said first thrust means (3) is positioned between said slider (2) and said housing (8), so as to obtain at least one closed contact profile between said closure element (5) and said second surface (26), wherein said release valve (100) is characterized in that said fluid exerts on said second surface (26) a pressing force greater than the pressing force exerted on said first surface (25), and in that said first (25) and second (26) surfaces are arranged in such a way that, if the pressure difference between said first environment (9) and said second environment (90) remains below a predetermined value, said first thrust means (3) realizes said closed contact profile between said closure element (5) and said slider (2).

Claims

1. Release valve (100), installable on a container intended to contain a pressurized fluid and capable of maintaining a pressure difference between a first environment (9) and a second environment (90), comprising a housing (8), a first thrust means (3), a closure element (5), and a slider (2), wherein said housing (8) contains at least said slider (2) and said first thrust means (3), wherein said slider (2) comprises a first surface (25) facing the first environment (9), and a second surface (26), facing the second environment (90), and having an area greater than said first surface (25), wherein said closure element (5) is interposed between said second environment (90) and said slider (2), and wherein said first thrust means (3) is positioned between said slider (2) and said housing (8), so as to exert a force until a safety value which maintains the slider (2) in a sealing configuration, in which at least one closed contact profile is obtained between said closure element (5) and said second surface (26), wherein said release valve (100) is characterized in that the first surface (25) and the second surface (26) are both in the first environment (9), and in that if the force exerted by the fluid on the first surface (25) and on the second surface (26) exceeds said safety value, said slider (2) switches from the sealing configuration to the release configuration, in which the at least one closed contact profile between said closure element (5) and said second surface (26) is not obtained.

2. Release valve (100) according to claim 1, characterized in that it comprises a shutter (1), positioned inside said slider (2), and a second thrust means (4), constrained on a wall (23) obtained on said slider (2) and positioned near said first environment (9), and on a surface (11) of said shutter (1), wherein said shutter (1) is configured to allow the loading and/or unloading of said fluid under pressure by pressing said shutter (1) against said second thrust means (4).

3. Release valve (100) according to claim 1, characterized in that said closure element (5) comprises one or more channels (10) or through openings, capable of keeping said first environment (9) in contact with said second environment (90) when said pressure difference exceeds said predetermined value.

4. Release valve (100) according to claim 1, characterized in that it comprises sealing means (60; 65) interposed between said slider (2) and said closure element (5).

5. Release valve (100) according to claim 1, characterized in that said closed contact profile is obtained on said closure element (5) and/or on said slider (2).

6. Release valve (100) according to claim 1, characterized in that said closure element (5) is made of polymeric material.

7. Release valve (100) according to claim 1, characterized in that it comprises: a first groove (85), a second groove (83), a limit (86) and a locking means (84), wherein said first groove (85) is delimited at the top by said limit (86) and is obtained on said slider (2) in a position such as to face said second groove (83) only when said pressure difference exceeds said preset value and the slider (2) is not in contact with the closure element (5), wherein said second groove (83) is formed on the internal wall (82) of said housing (8), and wherein said locking means (84) is adapted to pass from a contracted condition to an expanded condition and being housed in at least one of said first groove (85) and said second groove (83); wherein said first and second grooves (85, 83) are in a reciprocal position such as to allow said locking means (84) to pass from said contracted condition to said expanded condition only when said pressure difference exceeds said predetermined value and the slider (2) is not in contact with the closure element (5); and wherein said locking means (84) forms an interference with said limit (86) to prevent said slider (2) from returning to contact with said closure element (5).

8. Release valve (100) according to claim 1, characterized in that it comprises sealing means (64) for said first environment (9) and a sealing member (200), such as a threaded bush and the like, integral to said slider (2) and equipped with a sealing profile (210), intended to remain in contact with said sealing means (64) when said pressure difference does not exceed said predetermined value and the slider (2) is in contact with the closure element (5).

Description

[0028] The present invention will be now described, for illustrative but not limitative purposes, according to its preferred embodiments, with particular reference to the figures of the enclosed drawings, wherein:

[0029] FIG. 1 is a section of a first embodiment of the release valve according to the invention, installed on the chamber of a gas spring;

[0030] FIG. 2 is a section of a second embodiment of the release valve according to the invention;

[0031] FIGS. 3A and 3B represent sections of a third embodiment of the release valve according to the invention, in two configurations, one subsequent and another preceding the escape of gas;

[0032] FIG. 4 represents a fourth embodiment of the release valve according to the invention;

[0033] FIG. 5 represents in more detail the embodiment of the FIG. 4; and

[0034] FIG. 6 shows a construction detail of an embodiment of the valve according to the invention.

[0035] With reference to FIG. 1, the different components of the release valve are visible, generally indicated by 100, and comprising: [0036] a shutter 1 and a slider 2, slidingly coupled coaxially within a housing 8; [0037] a first safety thrust means 3, for example a spiral spring, which encloses a section of the slider 2 and is constrained between a step 81 obtained in the housing 8, and a wall 21 of the slider 2 itself; [0038] a second thrust means 4, for sealing, for example a spring constrained on an internal wall 23 of the slider 2 and on a surface 11 of the shutter 1; [0039] a closing ring 5, the central opening of which can act as a further guide for the shutter 1; [0040] a plurality of sealing means or gaskets 60, 61, 62, 63; and [0041] a stop ring 7.

[0042] In an alternative embodiment in which the shutter 1 is absent, the ring 5 can be replaced by a closure element without a central hole.

[0043] Furthermore, since the specific case of a valve applied to a chamber of a gas spring is treated, the chamber 9 of the spring itself is shown in the figures; more generally, the term chamber can be considered here as the volume or internal environment of a generic container, in which a pressurized fluid can be confined.

[0044] The valve therefore acts as a sealing element between the chamber 9 and an external environment 90.

[0045] The release valve 100 can preferably comprise the loading system, which includes for example the shutter 1 held in position by the spring 4.

[0046] In detail, an inlet section 31 can be provided, which is used to introduce the gas into the chamber 9. To carry out this operation, the sealing spring 4 is compressed, and by sliding the shutter 1 inside the cavity, the gas passes through the play between the shutter 1 itself and the internal wall of the slider 2.

[0047] When the service pressure is reached, the gas injection ends, the spring 4 is released and the shutter 1 returns to contact with the gasket 61 below. The chamber 9 is now therefore hermetically sealed, and the gas spring can be used.

[0048] This occurs thanks to the fact that the spring 3, which insists between the limit 81 of the housing 8 and the surface 21 of the slider 2, keeps the closing ring 5, the slider 2 itself, and the sealing means possibly interposed in mutual contact among them.

[0049] In service conditions, the gas contained in the chamber 9 exerts a pressure on the slider 2; more precisely, as visible in FIG. 1, the net force exerted by the gas is due to its action on a first surface 25 of the slider 2, the diameter of which is indicated with the reference A, and which faces the chamber 9 under pressure, and on a second surface 26, the diameter of which is indicated by the reference B, and which faces the external environment.

[0050] The arrows I, II, III illustrated in FIG. 1 show the path of the gas from the chamber 9 through the internal cavity of the slider 2 (I), the play between the shutter 1 and the slider 2 (II), and finally on the second surface 26 up to the seal 60 (III).

[0051] In other words, the gas, passing through the play between shutter 1 and slider 2, is able to exert a force also capable of urging the face 26 of the slider 2 itself, specifically the portion inside the contact line, between the face 26 and the sealing means 60.

[0052] Since the area of section A, relating to face 25, is smaller than the area of section B, relating to face 26, the force exerted by the gas on area B is greater than that exerted on area A; the presence of the thrust means 3, in the example acting on the limit 21 of the slider 2, compensates for this forces difference.

[0053] The spring 3 is able to oppose the axial force exerted by the gas up to a maximum pressure difference value between the environments 9 and 90, established during the design phase; the slider 2, therefore, is kept in contact with the closure element 5 until this pressure difference reaches the predetermined limit value.

[0054] More in detail, the closure element 5 can be made as a removable element, to be blocked for example by means of a stop ring 7 or the like, or it can be integrated with the internal wall of the housing 8.

[0055] Furthermore, according to the invention, the closure element 5 can be a threaded ring nut, to be engaged with a counter-thread made on the internal lower wall 87 of the housing 8, as shown in FIG. 6.

[0056] A closure element 5 thus made, allows to vary the force exerted by the spring 3, simply by screwing and unscrewing the ring nut, which will vary the size of the spring 3 itself and therefore the compression force exerted.

[0057] In the preferred embodiment shown in the attached figures, the closure element 5 has on its surface one or more through channels or openings 10, which facilitate the passage of the gas between the environments A and B.

[0058] As said, the gas contained in the environment 9 passes through the cavity of the slider 2 and exerts a force on the circular section of the surface 26 of the slider 2 itself; if the difference between the forces exerted by the gas on the faces 26 and 25 increases, for example due to an accumulation of liquids inside the chamber 9 or an excessive compression ratio between the two environments, beyond the safety value tolerable by the thrust means 3, the net force exerted on the slider 2, given by the sum of the force of the spring 3 itself and the gas forces on the faces 26 and 25, causes the slider 2 to be raised.

[0059] At this point, due to the relative separation between the slider 2 and the closure element 5, the gasket 60 interposed between them is no longer able to ensure the sealing of the environment 9; the gas and any accumulated liquid outflow through the channels 10, after having crossed the play between slider 2 and shutter 1, if this shutter 1 is present. Under these conditions, it is possible to outflow the liquid accumulated inside the chamber of the cylinder to which the valve is applied.

[0060] The arrows I, II, IV shown in FIG. 2 show the path of the gas from the chamber 9 through the internal cavity of the slider 2 (I), the play between the shutter 1 and the slider 2 (II), and finally through the channels 10 (IV).

[0061] After the expulsion of the excess gas quantity, the pressure value inside the chamber returns to a safety value, and the spring 3 reposition the slider 2 in contact with the gasket 60; furthermore, if suitably positioned, the valve also allows the gas to bring with it any liquids that may be present, such as lubricating oils and the like, which could prevent the gas spring from correctly returning to function.

[0062] According to further embodiments of the release valve 100, of which an example is shown in FIG. 2, the closure element 5 can be made of a suitable polymeric material, so that it can function itself as a sealing means; alternatively, a further element made of a material suitable for guaranteeing the seal can be interposed between the slider 2 and the closure element 5, thus being able to do without the seat for the gasket 60 shown in FIG. 1.

[0063] Furthermore, as shown in FIG. 2, profiles 40, 41 can be provided, respectively obtained on the slider 2 and/or on the shutter 1 (with a semi-circular section, for example), which insist on the closure element 5 to guarantee the seal of the chamber 9; vice versa, the profiles 40 and 41 could be obtained on the closure element 5, and would insist on the slider 2 and/or on the shutter 1.

[0064] Furthermore, as shown in FIG. 2, the slider 2 can also be equipped with a lip profile 43, in its upper portion or in any case close to the chamber 9, so that it acts as an additional sealing element.

[0065] It is clear the greater convenience of the invention described so far, especially if we consider that, in addition to having better characteristics than the prior art in terms of performance and operation, its design and construction allow the simple replacement of one or more components that should break following an increase in pressure or other malfunctions in general; similar operations, in fact, are not as simple in the valves currently known.

[0066] It is also clear that the valve according to the invention is suitable for use not only in the example described of a gas spring, but also in any other application field where it is necessary to maintain a predetermined pressure difference between two connected environments from the valve itself.

[0067] Another of the main advantages of the solution described so far is that of keeping the gas spring chamber, or in any case the pressure vessel, operating even in case the pressure is risen beyond a safety value; in the systems currently used, on the contrary, the irreversible breakage of at least one component of the assembly is foreseen as a final result, which causes the total leakage of the gas and consequently renders the system unusable in its entirety.

[0068] FIGS. 3A and 3B show an alternative embodiment of the release valve according to the invention: for greater simplicity, some construction details represented in the previously described variants, such as the sealing and safety springs, have not been represented.

[0069] It should be noted, however, that FIG. 3 must be interpreted considering the elements mentioned so far as being part of the present embodiment, the technical effect of which is that of allowing the complete outflow of the gas contained in the chamber upon reaching a limit pressure.

[0070] More in detail, a first groove or spline 85 is obtained on the slider 2, which in this case shown is delimited at the top by a limit 86 in the figures; on the inner wall 82 of the housing 8 it is instead obtained a second groove or spline 83.

[0071] A locking means 84 is housed inside the first groove 85, and it is at the same time in contact with the flat surface of the wall 82 itself.

[0072] The locking means 84 can be an elastic ring or in any case made of a material, for example polymeric or elastomeric, so that it is able to expand when the constraints surrounding it are removed.

[0073] Alternatively, the locking means 84 can comprise the last turn of the spring 3, shaped with a diameter greater than the average diameter of the rest of the spring 3 itself.

[0074] In particular, it passes from a contracted condition (FIG. 3B), in which its volume is limited between the walls of the first groove 85 and the wall 82, to an expanded condition (FIG. 3A), in which its volume is free to expand within the second groove 83.

[0075] The grooves 85 and 83 are positioned respectively on the slider 2 and on the wall 82, so that, while the slider 2 is in the sealing configuration (FIG. 3B), they do not face each other completely; in other words, the grooves 85 and 83 are positioned in such a way that the locking means 84 finds sufficient space to expand inside the second groove 83 only when the slider 2 reaches the release configuration.

[0076] As a result of the pressure increase, in fact, the slider 2 assumes the release configuration (FIG. 3A) and the first groove 85, dragging the locking means 84, facing the second groove 83.

[0077] At this point the containment space of the locking means 84 comprises the volume of the first groove 85 and also the volume of the second groove 83: the locking means 84, first contained by the first groove 85 and the wall 82, also expands within the second groove 83.

[0078] Once part of the gas has exited the chamber 9 and the pressure drops below the safety value, the slider 2 reverses its movement, driven by the safety spring (not shown). The locking means 84, now in the expanded condition, creates interference with the limit 86, which hits against it, preventing the return of the slider 2 to the sealing configuration; therefore the release valve does not close completely and the chamber empties itself of the gas.

[0079] The embodiment of FIG. 4 differs from the previous ones in the sealing methods between the slider 2 and the walls of the housing 8.

[0080] In this embodiment of the invention, the gaskets 60 and 61 shown in FIG. 1 are replaced by a single gasket 65, while the gaskets 62 and 63 present in FIG. 1 are replaced by a single gasket 64.

[0081] The thrust means 3 is not shown in FIG. 4 at issue to improve the intelligibility of the drawing.

[0082] The portion of the slider 2 which faces the room 9 is coupled to a sealing member 200, which in the embodiment shown is a threaded bush.

[0083] The threaded bush 200 can be coupled to the slider 2 during the assembly or installation of the valve 100, and is arranged to be screwed through its internal surface 201 to the external surface 20 of the slider 2, both suitably threaded.

[0084] The bush 200 is furthermore equipped with a profile 210 for contacting the sealing means 64, which in the case shown is a circular relief having a sealing function together with the sealing means 64 themselves.

[0085] Preferably, as said, in correspondence with the opposite ends of the slider 2, i.e. the one facing the environment 90, a gasket 65 can be provided, which replaces the two gaskets 60 and 61 of FIG. 1.

[0086] A profile 211, similar to the profile 210, can be obtained on the slider 2 in order to guarantee a perfect seal of the valve.

[0087] Advantageously, the shutter 1 is also in contact with the same gasket 65.

[0088] In this way it is possible to obtain through the same expedient the very significant technical improvements in the context of the invention: [0089] the number of pieces used is reduced, to the advantage of costs and production times, assembly and operation of the valve; [0090] a more effective seal is obtained, since the slider 2 realizes with the gasket 64 an axial seal, more effective and reliable than the radial seal typical of the embodiments of FIGS. 1 and 2; [0091] any undesirable effects due to friction between the sliding walls and the gasket itself are eliminated, for example the gluing.

[0092] FIG. 5 shows in more detail the threaded coupling between the slider 2 and the sealing member 200.

[0093] In this case the slider 2 and the sealing member 200 are configured to be screwed respectively through the internal surface 20 belonging to the slider 2 and the external surface 201 belonging to the sealing member 200.

[0094] An advantage of the present invention is that of allowing a high miniaturization and integration of the valve.

[0095] An advantage of the present invention is also the fact that the same can be used both in gas springs for molds and for other uses, in which it is necessary to ensure a predefined maximum internal pressure.

[0096] Another advantage of the present invention is that of allowing the loading, and eventually unloading, of the fluid under pressure to regulate the pressure inside the system.

[0097] A further advantage of the present invention is that of presenting a very reduced layout in terms of sizes so as to allow a high miniaturization of the valve.

[0098] The present invention has been described for illustrative but not limitative purposes, according to its preferred embodiments, but it is to be understood that modifications and/or changes can be introduced by those skilled in the art without departing from the relevant scope as defined in the enclosed claims.