DE9111351U1 - Valve for pressurized gas packs - Google Patents

Description

PATENT ATTORNEYS
DR.-iNG. H. NEGENDANK 1-1973) - ⁼ * ;

HAUCK, GRAALFS, WEHNERT, DÖRING, BEINES, SIEMONS 36 450-19 HAMBURG · MUNICH - DÜSSELDORF '^ "~"

PATENT AND LAWYER, NEUER WALL 41, 2000 HAMBURG 36

Aerosol technology LINDAL GmbH Industriestr. 13

2060 Bad Oldesloe

EDO GRAALFS, Dipl.-Ing. NORBERT SIEMONS, Dr. Dipl.-Ing. HEIDI REICHERT. Attorney at Law Neuer Wall 41, 2000 Hamburg 36 Telephone (040) 36 67 55, Fax 49-40-364039 Telex 211769 inpat d

HANS HAUCK, Dipl.-Ing. WERNER WEHNERT, Dipl.-Ing. Mozartstraße 23, 8000 Munich 2 Telephone (089) 53 92 36, Fax 49-89-531239 Telex 5216553 pamu d

WOLFGANG DÖRING, Dr.-Ing. ULRICH BEINES, Dr. rer. nat., Dipl.-Chem. Mörikestraße 18, 4000 Düsseldorf Telephone (0211) 45 07 85, Fax 49-211-4543283 Telex 858 40 44 dopa d

DELIVERY ADDRESS/PLEASE REPLY TO:

HAMBURG,

11 September 1991

Valve for pressurized gas packs

The innovation relates to a valve for pressurized gas packages according to the preamble of claim 1.

Depending on the medium contained, there is a certain excess pressure inside the compressed gas packs. The compressed gas packs are designed to withstand a much higher filling pressure. Due to chemical conversion or external influences, such as high temperatures, the pressure in the gas pack can approach critical values at which the container, such as a can made of tinplate or aluminum, bursts or the pressed-on valve is detached like a projectile. This danger exists

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Patent Attorneys · European Patent Attorneys ■ Authorized representatives before the European Patent Office

Legal appeal: admitted to the Hamburg courts

Deutsche Bank AG Hainburg, No. 05/28497 (BI,2 2Q0 700 DO) · Postgiro Hamburg 28 42-206 Dresdner Bank^AG iiambUEg,* NiC S33 SO 35JBLZ 200 800 00)

for example, in the case of products containing hydrogen peroxide, which can undergo catalytic decomposition.

Safety precautions for such cases are known in many cases. For example, DE-OS 20 64 953 discloses the provision of a safety valve in the base of an aerosol can. DE-OS 25 10 059 discloses the provision of a pressure relief valve in the lid-like valve carrier. DE-PS 15 01 747 discloses the provision of an opening in the lid-like valve carrier that is sealed by a membrane. The membrane detaches or tears at a certain excess pressure, so that pressure can be reduced. In contrast to the pressure relief devices described above, the last-mentioned safety precaution only works once and renders the aerosol can unusable after it has been activated. Pressure relief valves have the advantage that they close again when the excess pressure has been reduced. The aerosol can can then be used normally.

The last-mentioned category also includes a valve arrangement according to DE-OS 23 14 912, in which a valve element that can be operated from the outside cooperates in a sealing manner with another valve element that is located on a

elastomer seal. The other valve element is housed in a sleeve, which in turn is held by the valve carrier. At normal operating pressure, the position of the second valve element does not change, so that a passage is created between the valve elements by operating the first valve element. If the pressure inside the container increases, the piston-like second valve element is adjusted relative to the first, so that a passage is created again.

Finally, DE-OS 24 24 847 discloses a valve arrangement for aerosol containers in which the valve element of the empty container can be pressed into the interior in order to create a permanent connection between the empty container interior and the atmosphere. Such a safety precaution only serves to prevent the risk of explosion in empty or almost empty containers and is not suitable for reducing excess pressure during normal operation.

The invention is based on the object of creating a valve for pressurized gas containers in such a way that an overpressure protection is created in a simple manner, which prevents an explosion of the container and an explosive detachment of the discharge valve.

This object is achieved by the features of claim 1.

In the valve according to the invention, an overpressure device is arranged in the axial channel of the valve member, which connects the axial channel with the interior of the compressed gas pack when the pressure in the compressed gas pack reaches a predetermined overpressure. In conventional valves for compressed gas packs, the valve member is below the cross-bore or the sealing disc and is guided by the valve housing when it is moved axially against or with the spring. In the valve according to the innovation, the axial channel is extended downwards to accommodate the overpressure device. For this purpose, the axial channel can be enlarged in diameter in the lower area to create sufficient space for the overpressure device.

Various design solutions are conceivable for implementing the overpressure device. One of these is that the axial channel is connected to the interior of the compressed gas pack via an opening and the opening can be closed off by a sealing element that can be deformed, detached or destroyed at a certain overpressure. For example, a sealing element can be connected via an adhesive

bonding can be installed inside the channel and close the opening, whereby the adhesive bond allows the sealing element to be released when a certain pressure is reached. Alternatively, the sealing element can tear or burst at a certain pressure in order to equalize the pressure. In this case, the sealing element is a type of membrane. Finally, the sealing element can also be arranged in the opening or pressed against the opening using suitable means in such a way that it deforms at a certain excess pressure and creates a flow passage through the opening.

A membrane can also be formed by molding it in one piece with the plastic valve member, e.g. as a relatively thin skin in the second transverse bore.

According to a further embodiment of the innovation, the axial channel can have at least one second transverse bore below the first transverse bore, which can be closed off by the second sealing element. Alternatively, the axial channel can be opened downwards towards the interior of the compressed gas pack and the sealing element can be arranged at the lower end of the channel or in the channel. In the latter case, for example, the axial channel can have a lower channel section with an enlarged diameter and the sealing element can be arranged against the

shoulder formed between the channel sections.

According to a further embodiment of the invention, a plug made of elastomeric material is arranged axially fixed in the axial channel below the first transverse bore. The plug seals the channel downwards. The valve member has at least one second transverse bore in the area of the plug, and the plug is designed so that it normally blocks the second transverse bore, but is deformed above a predetermined overpressure so that it opens up a flow path from the transverse bore to the axial channel. For this purpose, the plug can be radially deformable in the area of the second transverse bore, for example, i.e. reduce its cross section so that the flow path is created. This can be achieved, for example, by making the plug hollow in the area to be deformed. The plug is preferably arranged in a lower channel section with an enlarged diameter. According to a further embodiment of the innovation, it can also have a conical sealing surface at the upper end, which cooperates to seal with the edge between the upper and lower channel sections. Above a certain pressure, the plug is deformed radially so that the sealing engagement with the edge between the channel sections is eliminated.

As already mentioned, the valve member is supported by a valve spring, which constantly presses the valve member into the sealing position. According to one embodiment of the innovation, this spring can be formed by an extension of the plug. As mentioned, the plug is made of an elastomer material. It can therefore also be deformed axially by a desired amount.

Another embodiment of the innovation provides that the axial channel has a lower section with a larger diameter and opens downwards, in which a piston is slidably mounted with an upper valve section with a smaller diameter. The valve section cooperates with a preferably conical valve surface to form a seal with the edge between the channel sections. When a predetermined differential pressure is reached on the piston, the valve section is pressed into the channel section with a smaller diameter. Below the valve surface, the valve section has at least one axial recess, via which and a transverse bore in the valve member above the piston a flow path is created between the interior of the gas pack and the atmosphere.

In yet another embodiment of the invention, the axial channel is provided via a transverse bore below the

The first cross-bore is connected to the interior of the compressed gas pack and a pressure relief valve in the channel works together with the second cross-bore. The pressure relief valve can have a spring-loaded valve element that is constantly pressed against the second cross-bore from the inside. Alternatively, a one-piece, relatively spring-hard elastomer part can be provided, which normally ensures a seal, but is removed from the second cross-bore in the event of excess pressure or is deformed to open up a flow path.

In a further alternative embodiment of the innovation, the axial channel in the valve member is open downwards, and the channel is provided with a section with an enlarged diameter below the cross-bore, into which a cylindrical extension protrudes into the lower channel section as an extension of the upper channel section, the free end of which forms a sealing surface for a disk-like sealing element made of elastomer material. The elastomer sealing element is deformed at its underside into the annular space between the extension and the channel at a predetermined overpressure. The extension has a cross-bore that connects the annular space to the upper channel section.

In the embodiments in which a very high filling

pressure could have an impermissible effect on the overpressure device or even render it unusable, it is expedient according to the invention to narrow the channel below the first transverse bore, i.e. to provide it with a throttle point. This reduces the pressure behind the throttle point.

The invention is explained in more detail below with reference to drawings.

Fig. 1 shows a section through a valve according to the invention.

Fig. 2 shows a section through a valve member modified from Fig. 1.

Fig. 3 shows the valve element according to Fig. 2 with piston.

Fig. 4 shows a section through the valve member according to Fig. 3 along the line 4-4.

Fig. 5 shows another embodiment for a valve member.

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Fig. 6 shows another embodiment for a valve member.

The valve according to Fig. 1 has a cover-like valve carrier 1 made of suitable metal, which is connected to a valve housing 2 by press forming. A radial flange 3 of the valve housing 2 is enclosed by the valve carrier 1 and is enclosed by a constriction 4 of the valve carrier 1.

A valve member 5 inserted into the valve housing 2 has an annular groove 6 on the outside into which a transverse bore 7 opens. The valve member 5 engages through a central opening of an annular sealing disk 8 and is pressed upwards by means of a spring 9 which is arranged in a cavity 10 of the valve housing 2.

The cavity 10 is connected to the interior of the compressed gas pack via a channel 11 that runs through a nozzle 12 formed on the valve housing 2. A riser pipe 13 is placed on the nozzle 12. A gap 14 between the valve housing 2 and the valve member 5 opens into the cavity 10 at its lower end and is sealed at the upper end by the sealing disk 8. The transverse bore 7 is connected to an axial channel 15 of the valve

- 11 members 5.

The sealing disc 8 is arranged in a receiving space of the valve housing 2, which is delimited by the flange 3 of the valve housing 2, the valve member 5 and the front wall 16 of the valve carrier 1. A peripheral edge 17 closes the receiving space to the outside. On the outside, the edge 17 defines the axial distance between the valve housing 2 and the front wall 16. When the valve carrier is crimped on, the upper end 18 of the edge 17 hits the front wall 16 of the valve carrier and the sealing disc 8 is firmly clamped in the receiving space, whereby it is deformed into a lower, radially outer, lowered area 19. This area is formed by the base 20 of the receiving space, which is lowered at an angle towards the edge.

A filling opening 21 for the propellant is formed between the valve member 5 and the end wall 16 of the valve carrier 1. The valve housing 2 has several channels 22 spaced apart in the circumferential direction, which form a filling path. During filling, the filling pressure acts on the sealing disc 8 and an edge 23 of the valve housing, so that the constriction of the valve carrier can temporarily deform downwards in order to form a path for the medium being filled in. It is understood that filling can also be carried out on other

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can be implemented in another way, for example as described in DE-PS 25 59 444.

By pressing down the valve member 5, for example via an attached spray head (not shown), an exit path is created for the propellant contained in the package and the product, whereby a connection is created between the transverse bore 7 and the gap 14 and thus via the riser pipe 13 with the interior of the package.

As can be seen, the channel 15 has a lower section 30 with an enlarged diameter, which is sealed at the bottom by an inserted plug 32. A cross hole 34 in the lower area of the valve member 5 connects the channel section 30 to the gap 14 or the cavity 10 and thus to the interior of the compressed gas pack. A plate-shaped sealing element 36 is attached to the inside of the hole 34, for example by gluing. If the pressure inside the pack rises to a predetermined value, the adhesive connection, for example, breaks, so that the sealing element 36 opens the flow path to the channel 15. However, the sealing element can also be destroyed at higher pressure, for example by tearing, so that the same effect of pressure equalization is achieved.

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Instead of the sealing element 36, a sealing element 38 shown in dashed lines can be attached to the shoulder between the bore sections, for example again by gluing. At a higher pressure, the sealing element 38 is deformed into the channel 15, leaving at least a small gap through which pressure equalization can take place. Alternatively, the sealing element 38 can also be a membrane that can be destroyed at higher pressure. In the case of the sealing element 38, the plug 32 is omitted and the channel section 30 is freely open at the bottom.

The sealing elements 36, 38 can also be formed by molding them in one piece with the valve member 5.

In the following figures 2, 3, 5 and 6, the valve member 5 according to Fig. 1 appears again, although it is slightly modified in each case. It is therefore provided with the same reference symbol, which in each case has a different index.

In Fig. 2, a plug 40 made of elastomeric material is inserted into the channel section 30a in a sealing manner. A section 42 protruding downwards over the channel section 30a,

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which has a blind bore 44, rests with a shoulder against the lower side of the valve member 5a. The section 46 seated in the channel section 30a has a blind bore 48 opening upwards. The upper end has a conical surface 50. If the pressure at the bore 34a is sufficiently high, the section 46 is compressed, so that a flow path is formed in the direction of the channel 15a for the purpose of pressure equalization.

The lower section 42 can replace the valve spring 9 according to Fig. 1. In the other case, appropriate shaping must ensure that a valve spring can engage.

As shown in dashed lines in Fig. 2, the plug 42 can form a valve section which, with the conical surface 50, seals against the edge formed between the channel sections 15a and 30a. At a certain overpressure in the packing, the overpressure valve section is deformed and opens up a flow path below the sealing edge.

A constriction 80 in the channel 15a ensures that the filling pressure behind the constriction 80 is reduced and does not push the plug 40 out of the section 30a.

In the embodiment according to Figures 3 and 4, a piston 50 made of elastomeric material is inserted into the channel section 30b in a sealing but sliding manner. It has a one-piece valve section 52 which cooperates with a conical sealing surface 54 at the upper free end to form a seal with the edge between the channel sections 15b and 30b. Due to the different effective surfaces, a differential pressure acts on the piston 50 in such a way that it is pressed in the direction of the channel section 15b. At a certain overpressure, the differential pressure is so great that the valve section 52 is pressed into the channel section 50. For this purpose, the valve section 52 can again be hollow or otherwise deformable so that the pressing takes place at the desired overpressure. As can be seen from Fig. 4, the valve section 52 has several axial recesses 56 over its circumference, which create a flow channel when the valve member 52 is partially seated in the channel 15b in order to carry out pressure equalization. The valve spring 9 according to Fig. 1 preferably also acts on the piston 50 so that it is always brought into the closed position and the described differential pressure is developed.

In the embodiment according to Fig. 5, the channel section 30c with an enlarged diameter is closed at the bottom,

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for example by a separate plate 60 which is attached by gluing. In the channel section 30c there is a valve member 62 of a pressure relief valve which is pressed against the transverse bore 34c by means of a spring 64. From a certain overpressure, the valve member 62 opens the transverse bore 34c so that pressure equalization can take place. Instead of a separate spring and a valve member, a one-piece elastically deformable component can also be used to create a pressure relief valve effect in conjunction with the transverse bore 34c.

In the embodiment according to Fig. 6, the valve member 5d lacks the transverse bore 34 according to Figs. 1 to 5. In the extension of the channel section 15d, a cylindrical section 66 is formed, which extends into the lower channel section 30d and which has a transverse bore 68. A relatively thick disk 70 made of elastomeric material rests against the projection 66 from below and seals the space below the disk 70. From a certain excess pressure, the piston-like disk 70 is deformed into the annular space between the projection 66 and the inner wall of the channel section 30d, whereby a flow path is created in this annular space, which is connected to the channel section 15d for the purpose of pressure equalization. It is understood that the projection 66 also extends downwards.

.../17

can be completely closed. For the described function, the opening of the extension 66 downwards is not necessary.

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Claims (15)

- 18 claims : 1. Valve for compressed gas packs, with a lid-like valve carrier made of metal, a valve housing with a radial flange which is enclosed by the valve carrier by press-forming, a valve member having an axial channel which is axially movably received by the valve housing and has an outer annular groove and a transverse bore connected to the axial channel, an annular sealing disk engaging in the groove, arranged in a receiving space of the valve housing and resting against the end wall of the valve carrier for sealing the transverse bore of the valve member, and a valve spring between the valve member and an abutment on the valve housing, characterized in that an overpressure device is arranged in the axial channel (15, 15a, 15b, 15c, 15d) of the valve member (5, 5a, 5b, 5c, 5d), which connects the axial channel to the interior of the compressed gas pack when the pressure in the compressed gas pack exceeds a predetermined overpressure reached. 2. Valve according to claim 1, characterized in that the axial channel (15) can be connected to the interior of the compressed gas pack via at least one opening (34) which .../19 a sealing element (36, 38) or the like that can be deformed, detached or destroyed at a certain excess pressure. 3. Valve according to claim 2, characterized in that the axial channel (15) below the first transverse bore (7) has at least one second transverse bore (34) which can be blocked off by the sealing element (36). 4. Valve according to claim 2, characterized in that the axial channel (15) is open downwards to the interior of the compressed gas pack and the sealing element (38) is arranged at the lower end of the channel or in the channel. 5. Valve according to claim 4, characterized in that the axial channel (15) has a lower channel section (30) with an enlarged diameter and the sealing element (38) rests against the shoulder formed between the channel sections (15, 30). 6. Valve according to claim 1, characterized in that in the axial channel (15a, 30a) below the transverse bore (7a) a plug (40) made of elastomeric material is arranged axially fixed and seals the channel downwards, the .../20 Valve member (5a) in the region of the plug (40) is designed such that it normally blocks the second transverse bore (34a) and is deformed above a predetermined overpressure so that it opens a flow path from the second transverse bore (34a) to the axial channel (15a). 7. Valve according to claim 6, characterized in that the plug (40) is radially deformable in the region of the second transverse bore (34a) and above it, i.e. can be reduced in cross-section. 8. Valve according to claim 7, characterized in that the radially deformable region is hollow, preferably by means of an axial bore (48) opening at the upper end. 9. Valve according to one of claims 6 to 8, characterized in that the plug (40) is arranged in a lower channel section (30a) with an enlarged diameter and cooperates with a preferably conical sealing surface (50) to form a seal with the edge between the upper and lower channel sections. 10. Valve according to one of claims 6 to 9, characterized .../21 indicates that the plug (40) projects downwards beyond the bottom open end of the axial channel. 11. Valve according to claim 1, characterized in that the axial channel (15b) has a lower section (30b) with an enlarged diameter and open downwards, in which a piston (50) is slidably mounted with a valve section (52) of smaller diameter, which cooperates with a preferably conical valve surface (54) to form a seal with the edge between the channel sections (15b, 30b), the valve section (52) can be pressed into the channel section (15b) of smaller diameter when a predetermined differential pressure is reached on the piston (50), at least one axial recess (56) is formed in the valve section (52) below the valve surface (54) and a transverse bore (34b) is provided in the valve member (5b) above the piston (50). 12. Valve according to claim 11, characterized in that the valve member (52) is hollow in the interior. 13. Valve according to claim 1, characterized in that the axial channel (15c, 30c) below the transverse bore (7c) via a further transverse bore (3 4c) with the interior .../22 the compressed gas pack can be connected and a pressure relief valve (62, 64) interacts with the second transverse bore (34c). 14. Valve according to claim 1, characterized in that the axial channel (15d, 30d) is open downwards, the channel below the transverse bore (7d) has a section (30d) with an enlarged diameter, in extension of the upper channel section (15d) a cylindrical appendage (66) projects into the lower channel section (30d), the free end of which forms a support for a disk-like sealing element (70) made of elastomeric material which, at a predetermined overpressure, is deformed on the underside into the annular space between the appendage (66) and the channel wall, and the appendage (66) has a transverse bore (68) which connects the annular space to the upper channel section (50d). 15. Valve according to one of claims 3 to 14, characterized in that the axial channel (15a) has a constriction (80) below the first transverse bore (7a).