US3823849A

US3823849A - Valve for delivering a liquid from an aerosol container

Info

Publication number: US3823849A
Application number: US00231964A
Authority: US
Inventors: T Ruscitti
Original assignee: Coster Technologie Speciali SpA
Current assignee: Coster Technologie Speciali SpA
Priority date: 1971-03-30
Filing date: 1972-03-06
Publication date: 1974-07-16
Anticipated expiration: 1991-07-16
Also published as: DE2215605A1; DE2215605C3; AT316412B; CH533266A; DE2215605B2; JPS5330167B1; ES400319A1; GB1370240A; FR2131319A5

Abstract

A valve for delivering a liquid from an aerosol container, comprising a rigid body member seamed to a bottom attachable on a container mouth or inlet and having side and bottom walls defining a cavity, a first shutter which is accomodated and movable within the cavity of said rigid body member, a tubular element having one end projecting from the bottom on the opposite side to that from which said body member projects and its other end fast with said first shutter, a resilient sealing member between the rigid body member and the bottom and having a hole, in which said tubular element is forced and can move and swing, at least one passage between the inside of the tubular element and the cavity of the rigid body member adjacent to said first shutter, at least one free hole in said side wall of the rigid body member, at least one spring acting on the first shutter by pressing it against said sealing member to close said passage, a hole being provided in the bottom wall of the rigid body member, at which hole a hollow extension projects from the rigid body member, on which extension the inlet of a deformable bag can be superimposed, this bag containing said liquid and capable of being accomodated within said container, said valve being characterized in that an annular resilient strip can be superimposed to the outer surface of the side wall of said rigid body member, this strip being forced on the side wall, superimposed to and sealing the hole in said wall, and in that at the bottom end of said first shutter means are provided for closing the hole in said bottom wall of the rigid body member under the conditions where said tubular element and first shutter are displaced against the action of said spring to press on said bottom wall.

Description

United States Patent [191 Ruscitti 1 VALVE FOR DELIVERING A LIQUID FROM AN AEROSOL CONTAINER [75] Inventor: Tomaso Ruscitti, Milan, Italy [73] Assignee: Coster Technologie Speciali S.p.A.,

- Milan, Italy [22] Filed: Mar. 6, 1972 [21] Appl. No.: 231,964

[30] Foreign Application Priority Data Primary Examiner-Stanley H. Tollberg [57] ABSTRACT A valve for delivering a liquid from an aerosol container, comprising a rigid body member seamed to a bottom attachable on a container mouth or inlet and having side and bottom walls defining a cavity, a first [451 July 16, 1974 shutter which is accomodated and movable within the cavity of said rigid body member, a tubular element having one end projecting from the bottom on the opposite side to that from which said body member projects and its other end fast with said first shutter, a resilient sealing member between the rigid body member and the bottom and having a hole, in which said tubular element is forced and can move and swing, at least one passage between the inside of the tubular e1- ement and the cavity of the rigid body member adjacent to said first shutter, at least one free hole in said side wall of the rigid body member, at least one spring acting on the first shutter by pressing it against said sealing member to close said passage, a hole being provided in the bottom wall of the'rigid body member, at which hole a hollow extension projects from the rigid body member, on which extension the inlet of a deformable bag can be superimposed, this bag containing said liquid and capable of being accomodated within said container, said valve being characterized in that an annular resilient strip can be superimposed to the outer surface of the side wall of said'rigid body member, this strip being forced on the side wall, su-

, perimposed to and sealing the hole in said wall, and in that at the bottom end of said first shutter means are provided for closing the hole in said bottom wall of the rigid body member under the conditions where said tubular element and first shutter are displaced against the action of said spring to press on said bottom wall.

6 Claims, 9 Drawing Figures PATENTEB JUL 1 8 I974 SHEEY 1 OF 4 PATENTEDJUU 6 I974 sumaora a I i k wh/nrii PATENTEB JUL 1 6 I974 sum 1; or 4 This invention relates to a valve for delivering a liquid from an aerosol container, and more particularly to a valve applicable to an aerosol container and suitable to deliver a liquid, avoiding any mixing thereof with a propelling gas.

Ordinary aerosol containers have a liquid therein, directly contacting a propelling gas, the latter imparting the required pressure to the liquid for a violent ejection thereof through the nozzle of a delivery valve which is applied to the container. In some cases, a direct contact between the propelling gas and liquid to be delivered is absolutely undesirable and therefore is to be avoided on the whole. The liquid being delivered through valves applied to these containers is mixed with the propelling gas.

Containers are also known as provided with valves, through which a liquid can be delivered by the action of a propelling gas, without any mixing or direct contact of the liquid with said gas, but in addition to being ofa rather complex structure, such valves requirethat the propelling gas is introduced into the container prior to seaming thereon the bottom to which the valve is applied, with a somewhat complex and expensive procedure. In further conventional containers of this type, the introduction of the propelling gas is accomplished through a hole in the bottom of the containers.

The main object of the present invention is to provide a valve which can be applied to an aerosol container and suitable to keep as separate a liquid to be delivered from the valve and a propelling gas within the contamer.

Another object of the invention is to provide a valve of the above character which, after being sealingly applied to a container, will allow for directly introducing the propelling gas into the container through said valve, avoiding any contact thereof with the liquid in a de- 4 formable bag which has been previously mounted on cavity, a first shutter which is accomodated and movable within the cavity of said rigid body member, a tubular element having one end projecting from the bottom onthe opposite side to that from which said rigid body member projects and its other end fast with said first shutter, a resilient sealing member clamped between the rigid body member and the bottom and having a hole, in which said tubular element is forced and can move and swing, at least one passage between the inside of the tubular element and the-cavity of the rigid body member adjacent to said first shutter, at least one free hole in said side wall of the rigid body member, at

least one spring acting on the first shutter by pressingit against said sealing member to close said passage, a hole being provided in the bottom wall of the rigid body member, at which hole a hollow extension projects from the rigid body member, on which extension the inlet of a deformable bag can be superimposed, this bag containing said liquid and capable of being accomodated within said container, said valve being characterized in that an annular resilient strip can be superimposed to the outer surface of the side wall of said rigid body member, this strip being forced on the side wall, superimposed and sealing the hole in said wall,

and in that at the bottom end of said first shutter means are provided for closing the hole in said bottom wall of the rigid body member under the conditions where said tubular element and first shutter are displaced against the action of said spring to press on said bottom wall.

For a more complete understanding of the valve structure and features, some embodiments thereof will now be described, as given by mere way of not limiting example, referencev being had to the accompanying drawings in which:

FIG. 1 is an axial sectional view showing a valve mounted on a container, the valve being at a rest conditron;

FIG. 2 is a sectional view of the valve at operative or I delivery condition;

FIG. 3 is a sectional view showing a valve as apropelling gas is being introduced into a container, on which said valve is mounted;

FIGS. 4, 5 and 6 are still axial sectional views showing respectively, a second embodiment of the valve at a rest condition and at an operative or delivery condition, and as a propelling gas is introduced under pressure into a container on which the valve is mounted; and

embodiment of the valve, respectively, at rest, operative or delivery conditions, and as a propelling gas is being introduced into a container, of which said valve is a part.

Referring first to FIGS. 1-3, a first embodiment of the valve is shown therein. By interposing a seal 3, a rigid body member, having a side wall 4 and a bottom wall 5 defining a cavity within said rigid body member,

isseamed to the central portion of a metal bottom 1, which is attached to the inlet of a container 2, on the v top portion of side wall 4 a seat being formed, accomodating therein a seal 6 which is clamped against said bottom 1, a continuous relief rim cooperating to this clamping effect and projecting from wall 4 to seal 6, as clearly shown in the drawings.

A first shutter 7 and a second shutter 8 are ac.-

said finger 10 can oscillate in recess 9, causing the second shutter to oscillate, as a result of a sidewise oscillation of the first shutter. A spring 11 is also accomodated within the cavity defined by

said walls

4 and 5 of the rigid body member, one end of this spring abutting on a collar projecting from shutter 7, and the other end of the spring abutting on a collar projecting from FIGS. 7, 8 and 9 are axial sectional views for athird shutter 8, said spring acting to urge said two shutters away from each other, that is tending to retain the two shutters at the position as shown in FIG. 1.

At the top of shutter 7 a cavity is provided and a plurality of radial ribs 12 project therefrom, one end of a tubular element 13 being forced and clamped therebetween, which tubular element 13 is forced, movable and swingable through a hole provided in seal 6, and has its other end projecting from bottom 1 on the opposite side to that from which said rigid body member of the valve projects.

At least one hole 14 is provided in the side wall 4 of said rigid valve body member, whereas a further hole 15 is provided in the bottom wall 5, at which a hollow extension 16 projects and has the inlet 17 ofa deformable bag 18 mounted thereon, this bag 18 being made, for example, of plastic material or rubber.

This inlet 17 of bag 18 is somewhat elongated and extends on the side wall 4 of said rigid valve body member, overlying said hole 14 and sealing the same. The

inlet 17 forms an annular resilient strip which can be superimposed on the-outer surface of the sidewall 4 and seal the hole 14 in the sidewall. In the embodiments shown in FIGS. 1-9, the annular resilient strip is integrally formed with the bag 18. However, the annular resilient strip can be formed as a distinct, resilient ring which is not an integral part of the bag.

At a rest condition of the valve, as shown in FIG. 1, shutter 8 is pressed on the bottom wall of the rigid body member of the valve and closes hole 15 communicating the inside of container 18 with the cavity of said rigid'body member.

Finally, on considering FIGS. 1 and 2, it will be seen that a delivery cap 19 is mounted on the free end of said tubular element 13 and provided with outlet nozzles, the cap being capable of oscillating relative to the valve bottom.

Assume that after filling the deformable bag 18 with the liquid to be delivered through the valve, and overlying the inlet 17 of the so filled up deformable bag on the extension 16 and on the side wall 4 of the rigid valve body member, and introducing said bag 18 into the container 2 and sealingly seaming said bottom 1 thereon, the lower end 20 of a machine is lowered on the container 2 without said cap 19, themachine being of a type well known in the art and thus not shown in detail herein, but only schematically shown in FIG. 3. Said machine end 20 operates on the tubular element 13, downward urging it until the lower end of finger rests on the second shutter 8, the latter being forced on the bottom wall 5 of the rigid valve body member and closing said hole 15, that is shutting off the communication between the deformable bag 18 and the'internal cavity of the rigid body member.

Now, a pressure gas is supplied from themachine, the lower end 20 of which is schematically shown in FIG. 3, this pressure gas passing through the cavity of tubular element 13, the space between said ribs 12 and entering the cavity of said rigid valve body member, the pressure gas passing therefrom directly into the container 2 through hole 14, after causing the resilient container inlet 17 to be lifted off of said hole.

It is important to-note that shutter 8 is held pressed on the bottom wall 5, keeping hole closed, also because of the gas pressure entering the cavity of body 4, as above described. Thus, the gas pressure in the cavity of body 4, as the propelling gas is supplied to the container, is higher than the pressure said gas has within the container and higher as well than the pressure existing within said bag 18, since said propelling gas undergoes load losses on passing through hole 14 and on being diffused through the space between the outer surface of wall 4 and the adjacent surface of the deformable bag inlet 17. 4

Thus, it is apparent that the above described valve allows for introducing the propelling gas into the container 2, after said valve has been steadily and definitely mounted onto the container, and that any risk is avoided that the propelling gas may also enter the deformable bag 18.

This is a significant feature of the above described valve, and it can be seen that after the lower end 20 of the pressure gas supply machine has been lifted off of the valve and said valve has been moved back to its rest condition, as shown in FIG. 1, shutter 7 being pressed by spring 11 against seal 6, any propelling gas in the container cannot flow back into the valve cavity, as said deformable bag inlet 17 will tightly seal said hole I 14, either because said inlet is resiliently forced onto said wall 4, or because the gas pressure operates on said inlet 17. It should be noted that, as the end 20 of said machine is lifted by the tubular element 13, the 'gas within the cavity of the rigid valve body member is caused to exit. Of course, within the container 2 the propelling gas can be totally at a gaseous state or partially at a liquid state, in which case there will be on the container bottom an amount 21 of liquified gaswhich would act as a reserve and would evaporate during the container use to make up for the decrease in volume of the deformablebag as a result of the delivery of liquid therein contained. In order to deliver the liquid through the valve, one needs only to impart an oscillation to said tubular element 13, acting by a finger on the delivering cap 19, as shown in FIG. 2, from which it will be seen that the finger 10 of the first shutter operates on the second shutter 8, causing it to oscillate sidewise and at least partly lifting it off of the bottom wall 5 of the rigid body member, thus opening said hole 15 and enabling the liquid in the deformable bag, as compressed by the propelling gas entrained in the container 2, to exit through said hole 15, enter the cavity defined by

walls

4 and 5 of the valve body and exit through the cavity of the tubular element 13 and then through the nozzles in the delivering cap after passing through the passage defined between the tubular element 13 and the first shutter 7, at said radial ribs 12, since the upper free edge of the first shutter would be no longer kept pressed on the entire periphery against seal 6.

From the foregoing it will be apparent that the structure of the valve is very simple and its operation is reliable and, particularly, that the liquid in bag 18 cannot be mixed with the propelling gas either when the container is being pressurized, or during delivery step.

Referring now to FIGS. 4, 5 and 6, an embodiment of the valve different from that in FIGS. l-3 is shown therein. In said FIGS. 4, 5 and 6, the same reference numerals have been used as those in the preceding figures to designate the same structural components, the container not having been shown in FIGS. 5 and 6, whereas on the free end of the tubular element 13 outwardly of the container neither the delivering cap, nor the lower end of the machine for introducing the pressure gas into the container have been shown.

The valve in FIGS. 4, 5 and 6 differs from that in FIGS. 1-3 essentially in that the tubular element 13 is fast with a shutter 22, similar to the above described shutter 7, and at its lower end having an elongated spoke 23 with a larger cross-section than that of the hole 15 in the bottom wall of the rigid valve body member. Such is the length of said spoke 23 that, at valve rest condition (FIG. 4), the spoke is moved away from the bottom wall 5, enabling a free communication between the inside of deformable bag 18 and the cavity defined by the walls 4and 5 of the rigid valve body member.

On the contrary, when the tubular element 13 along with shutter 22 is fully downward pressed from the lower end of the machine for propelling gas introduction, the lower end of the elongated spoke 23 will overlie hole 15, thus preventing the gas' from penetrating into the deformable bag and instead allowing it to outflow through the hole 14 in wall 4, by raising the inlet 17 of said container (FIG. 6). I

In order to deliver liquid only by the valve, it will suf fice to impart a sidewise oscillation (FIG. 5) to said tubular element for the liquid to outflow from the containerthrough hole l5, passage defined between seal 6 and the upper edge of shutter 22, and the passage as defined between said tubular element 13 and shutter 22, similarly as above described and as evident from FIG. 5.

Preferably, a resilient ring-shaped seal 24 is accommodated on the bottom wall 5 of the ridid valve body member, the seal bore overlying hole 15,.whereas the spring urging said shutter 22 to seal 6 abuts on seal 24, as shown in the drawing.

FIGS. 7-9 illustrate a further embodiment of the valve, for which the same disclosure as to the embodiment in FIGS. 4-6 is also true. In the valve as shown in FIGS. 7-9, a shutter 25 is fast with the tubular element 13 and provided with radial ribs spacing it apart from said element 13, an elongated spoke 26 projecting from the lower end of this shutter 25 and extending to the hole 15 in the bottom wall 5. In said bottom wall 5 a housing or seal 27 is formed, of which the downward facing surface is smooth and the side surface of which is crossed by a plurality of grooves, as shown in the drawings. A disc-shapedresilient seal 28 is accommodated in seat 27, this seal being movable therein and retained therein by the lower end of spoke 26.

Under valve rest'conditions, the lower end of spoke 26 is held far away. from the bottom wall 5 of the rigid valve body member due to a spring 29, while per simple gravity said seal 28 bears on the bottom wall 5 (FIG. 7).

When introducing a pressurized propelling gas into the container, on which the, valve is mounted (FIG. 9), the tubular element or valve stem 13 is kept downward urged and the lower end of spoke 26 presses the seal 28 on the bottom wall 5 of the valve body, tightly closing hole 15 and preventing pressure gas from penetrating into the deformable bag, as shown in FIG. 9

Should the valve stein, along with said shutter 25, be sidewise oscillated from the rest condition as shown in FIG. 7 (see FIG. 8), as above described a communica- I tion would be established between the valve stem cavseal accomodating seat would thus penetrateiinto the valve cavity and then exit. i

In all of its embodiments, the inventive valve prevents the propelling gas from being mixed with the liqshutter which is accommodated and movable within the cavity of said rigid body member, a tubular element having one end projecting from the bottom on the opposite side to that from which said body member projects and its other end fast with said first shutter, a resilient sealing member clamped between the rigid body member and the bottom and having a hole, in which said tubular element is forced and can move and swing, at least one passage between the inside of the tubular element and the cavity of the rigid body member adjacent to said first shutter, at least one free hole in said side wall of the rigid body member, at least one spring acting on the first shutter by pressing it against said sealing member to close said passage, a hole being provided in the bottom wall of the rigid body member, at which hole a hollow extension projects from the rigid body member, on which extension the inlet of a deformable bag can be superimposed, this bag containing said liquid and capable of being accommodated within said container, said valve being characterized in that an annular resilient strip can be superimposed to the outer surface of the side wall of said rigid body member, this strip being forced on the side wall, superimposed to and sealing the hole in said wall, and in that at the bottom of said first shutter means are provided for closing the hole in said bottom wall of the rigid body member under the conditions where said tubular element and first shutter are displaced against the action of said spring to. press on said bottom wall; and, wherein said means provided at the lower end of the first shutter for closing the hole in the bottom wall of the rigid body member comprise a second shutter, between which and the first shutter said spring is located, in one of said two shutters a recess being formed, a finger projecting from the other of said two shutters, said finger extending within said recess and having slightly higher transverse dimensions than those of said finger, the free end of the finger being spaced apart from the opposing surface of the recess under valve rest conditions and contacting said recess surface, h olding said second shutter pressed on the rigid body member to close the hole in its bottom wall, under the conditions where said tubular element is urged to said bottom wall against the action of said spring.

2. A valve for delivering a liquid from an aerosol container, comprisinga rigid body member seamed to a bottom attachable on a container mouth or-inlet and having side and bottom walls defining a cavity, a first shutter which is accommodated and movablewithin the cavity of said rigid body member, a tubular element having one end projecting from the bottom on the 'opposite side to that from which said body member projects and its other end fast with said first shutter, a resilient sealing member clamped between the rigid body member and the bottom and having a hole, in which said tubular element is forced and can move and swing, at least one passage between the inside of the tubular element and the cavity of the rigid body member adjacent to said first shutter, at least one free hole in said side wall of the rigid body member, at least one spring acting on the first shutter by pressing it against said sealing member to close said passage, 21 hole being provided in the bottom wall of the rigid body member, at which a hole a hollow extension projects from the rigid body member, on which extension the inlet of a deformable bag can be superimposed, this bag containing said liquid and capable of being accommodated within said container, said valve being characterized in that an annular resilient strip can be superimposed to the outer surface of the side wall of said rigid body member, this strip being forced on the side wall, superimposed to and sealing the hole in said wall, and in that at the bottom end of said first shutter means are provided for closing the hole in said bottom wall of the rigid body member under the condition where said tubular element and first shutter are displaced against the action of said spring to press on said bottom wall; and, wherein said means provided at the lower end of the first shutter for closing the hole in the bottom wall of 25 the rigid body member comprise an elongated finger projecting from said first shutter and having a larger cross-section than that for the hole of said bottom wall,

the free end of the rigid body member being moved away from the bottom wall of the rigid body member under the valve rest conditions, and being pressed on said bottom wall and closing said hole under the conditions where said tubular element is urged to the bottom wall against the action of said spring.

3. A valve as claimed in claim 1, wherein said means provided at the lower end of the first shutter for closing the hole in the bottom wall of the rigid body member comprise a second shutter, between which and the first shutter said spring is located, in one of said two shutters a recess being forced, a finger projecting from the other of said two shutters, said finger extending within said recess and having slightly higher transverse dimensions than those of said finger, the free end of the finger being spaced apart from the opposing surface of the recess under valve rest conditions and contacting said recess surface, holding said second shutter pressed on the rigid body member to close the hole in its bottom wall, under the conditions where said tubular element is urgedto said bottom wall against the action of said spring.

4. A valve as claimed in claim 1, wherein said means provided at the lower end of the first shutter for closing the hole in the bottom wall of the rigid body member comprise an elongated finger projecting from said first shutter and having a larger cross-section than that for the hole of said bottom wall, the free end of the rigid body member being moved away from the bottom wall of the rigid body member under the valve rest conditions', and being pressed on said bottom wall and closing said hole under the conditions where said tubular element is urged to the bottom wall against the action of said spring.

5. A valve as claimed in claim 2, wherein a ringshaped resilient seal is accomoodated on the bottom wall of the rigid body member, the bore of said seal overlying the hole in said bottom wall, said spring acting on said first shutter and said ring-shaped resilient seal.

6. A valve as claimed in claim 2, wherein a seal is formed in the bottom wall of the rigid body member at the hole in said bottom wall, the side surface of said seat having at least one groove, a disc-shaped resilient seal being accomodated in said seat, said seal being movable within said seat and retained therein by the

Claims

1. A valve for delivering a liquid from an aerosol container, comprising a rigid body member seamed to a bottom attachable on a container mouth or inlet and having side and bottom walls defining a cavity, a first shutter which is accommodated and movable within the cavity of said rigid body member, a tubular element having one end projecting from the bottom on the opposite side to that frOm which said body member projects and its other end fast with said first shutter, a resilient sealing member clamped between the rigid body member and the bottom and having a hole, in which said tubular element is forced and can move and swing, at least one passage between the inside of the tubular element and the cavity of the rigid body member adjacent to said first shutter, at least one free hole in said side wall of the rigid body member, at least one spring acting on the first shutter by pressing it against said sealing member to close said passage, a hole being provided in the bottom wall of the rigid body member, at which hole a hollow extension projects from the rigid body member, on which extension the inlet of a deformable bag can be superimposed, this bag containing said liquid and capable of being accommodated within said container, said valve being characterized in that an annular resilient strip can be superimposed to the outer surface of the side wall of said rigid body member, this strip being forced on the side wall, superimposed to and sealing the hole in said wall, and in that at the bottom of said first shutter means are provided for closing the hole in said bottom wall of the rigid body member under the conditions where said tubular element and first shutter are displaced against the action of said spring to press on said bottom wall; and, wherein said means provided at the lower end of the first shutter for closing the hole in the bottom wall of the rigid body member comprise a second shutter, between which and the first shutter said spring is located, in one of said two shutters a recess being formed, a finger projecting from the other of said two shutters, said finger extending within said recess and having slightly higher transverse dimensions than those of said finger, the free end of the finger being spaced apart from the opposing surface of the recess under valve rest conditions and contacting said recess surface, holding said second shutter pressed on the rigid body member to close the hole in its bottom wall, under the conditions where said tubular element is urged to said bottom wall against the action of said spring.

2. A valve for delivering a liquid from an aerosol container, comprising a rigid body member seamed to a bottom attachable on a container mouth or inlet and having side and bottom walls defining a cavity, a first shutter which is accommodated and movable within the cavity of said rigid body member, a tubular element having one end projecting from the bottom on the opposite side to that from which said body member projects and its other end fast with said first shutter, a resilient sealing member clamped between the rigid body member and the bottom and having a hole, in which said tubular element is forced and can move and swing, at least one passage between the inside of the tubular element and the cavity of the rigid body member adjacent to said first shutter, at least one free hole in said side wall of the rigid body member, at least one spring acting on the first shutter by pressing it against said sealing member to close said passage, a hole being provided in the bottom wall of the rigid body member, at which a hole a hollow extension projects from the rigid body member, on which extension the inlet of a deformable bag can be superimposed, this bag containing said liquid and capable of being accommodated within said container, said valve being characterized in that an annular resilient strip can be superimposed to the outer surface of the side wall of said rigid body member, this strip being forced on the side wall, superimposed to and sealing the hole in said wall, and in that at the bottom end of said first shutter means are provided for closing the hole in said bottom wall of the rigid body member under the condition where said tubular element and first shutter are displaced against the action of said spring to press on said bottom wall; and, wherein said means provided at the lower end of the first shutter for closing the hoLe in the bottom wall of the rigid body member comprise an elongated finger projecting from said first shutter and having a larger cross-section than that for the hole of said bottom wall, the free end of the rigid body member being moved away from the bottom wall of the rigid body member under the valve rest conditions, and being pressed on said bottom wall and closing said hole under the conditions where said tubular element is urged to the bottom wall against the action of said spring.

3. A valve as claimed in claim 1, wherein said means provided at the lower end of the first shutter for closing the hole in the bottom wall of the rigid body member comprise a second shutter, between which and the first shutter said spring is located, in one of said two shutters a recess being forced, a finger projecting from the other of said two shutters, said finger extending within said recess and having slightly higher transverse dimensions than those of said finger, the free end of the finger being spaced apart from the opposing surface of the recess under valve rest conditions and contacting said recess surface, holding said second shutter pressed on the rigid body member to close the hole in its bottom wall, under the conditions where said tubular element is urged to said bottom wall against the action of said spring.

4. A valve as claimed in claim 1, wherein said means provided at the lower end of the first shutter for closing the hole in the bottom wall of the rigid body member comprise an elongated finger projecting from said first shutter and having a larger cross-section than that for the hole of said bottom wall, the free end of the rigid body member being moved away from the bottom wall of the rigid body member under the valve rest conditions, and being pressed on said bottom wall and closing said hole under the conditions where said tubular element is urged to the bottom wall against the action of said spring.

5. A valve as claimed in claim 2, wherein a ring-shaped resilient seal is accomoodated on the bottom wall of the rigid body member, the bore of said seal overlying the hole in said bottom wall, said spring acting on said first shutter and said ring-shaped resilient seal.

6. A valve as claimed in claim 2, wherein a seal is formed in the bottom wall of the rigid body member at the hole in said bottom wall, the side surface of said seat having at least one groove, a disc-shaped resilient seal being accomodated in said seat, said seal being movable within said seat and retained therein by the free end of said elongated finger.