EP1474344A1

EP1474344A1 - Pressure container for viscous substances

Info

Publication number: EP1474344A1
Application number: EP03706444A
Authority: EP
Inventors: Ingo Rackwitz
Original assignee: Thomas GmbH
Current assignee: Nestec SA
Priority date: 2002-02-13
Filing date: 2003-02-06
Publication date: 2004-11-10
Anticipated expiration: 2023-02-06
Also published as: ATE358075T1; JP2005517597A; RU2004127232A; MXPA04007945A; CN1630605A; DE10206077A1; EP1474344B1; US20050145654A1; DE50306902D1; AR038489A1; CA2475907A1; BR0303071A; US7278557B2; WO2003068632A1; AU2003208807A1

Abstract

A pressure container used to receive viscous substances, provided with an outlet valve (14) which can be moved between a closed and an open position. A moveable valve element (18) can be displaced towards the inside of the container in order to release the opening cross-section. Since a large opening diameter is desired and a very high initial resistance must be overcome as a result of the large size of the parts entering the interior of the container, at least two opening cross-sections which can be successively released by actuating the valve are provided. A low initial actuating force is thus obtained while the opening cross-section remains large and the valve (14) is fully opened.

Description

Pressure container for viscous substances

The present invention relates to a pressure container for receiving viscous substances with an outlet valve which is adjustable between a closed position and an open position, a movable valve element being movable in the direction of the interior of the container in order to release an opening cross section.

A particular problem with highly viscous substances which are to be stored in handy pressure containers similar to known aerosol spray cans is that a relatively large opening cross section must be provided when the outlet valve is open in order to achieve a satisfactory dispensing of the substance after the valve has been actuated , On the other hand, given the system pressure of, for example, 10 bar and the viscosity of the substance, the problem arises that the valve element must then have a correspondingly large area in order to release the opening cross-section, as a result of which the force for actuating the exhaust valve increases in an impractical manner. This problem is exacerbated by frozen pressure vessels and the resulting ice formation, which can further increase the opening force required.

Alternatively, a rotary valve is already known from EP 1 167 842, in which the penetration of part of the valve element into the interior of the container when moving into the open position is avoided. Difficulties exist here in the region of the seal, since the sealing material for Errei ^¬ monitoring a permanent sealing action with a specific Pressure must be applied, the volume of the sealing material can change due to swelling under the influence of the substance stored in the container. This can either damage the seal or increase the actuation forces, which can cause the valve to get stuck. A permanent gas tightness and the fulfillment of, for example, food law regulations for the storage of food in the pressure container are further self-evident requirements.

The object of the present invention is to create a pressure container for holding viscous substances even in the deep-frozen state, the outlet valve of which functions reliably in the long term.

According to the invention, the object is achieved in that at least two opening cross sections are provided in a pressure container of the type described at the outset, with actuation of the valve firstly a first opening cross section, which is preferably defined by a first sealing element and a first closing element, and subsequently at least one further opening cross section , which is preferably defined by a further sealing element and a further closing element, can be released.

The pressure container according to the invention has the advantage that, with correspondingly smaller actuation forces, only a small cross section is initially released, ie. H. only a small volume is displaced by the valve element penetrating into the interior of the container. After opening the first one

Cross-section, the viscous mass can flow into the outlet at a comparatively low throughput, so that in the loading Rich in the sealing points, a certain pressure equalization is created and also the structure of the substance is loosened by the outflow movement, so that with a comparatively low actuating force by further actuation of the valve element, the second opening cross section can also be released and subsequently the substance through the large overall cross section can flow. In this way, on the one hand, the actuation forces for opening the valve are reduced and, on the other hand, the opening cross-section required to discharge a certain volume per unit of time is nevertheless made possible.

The closing process takes place in reverse, the closing movement being supported on the one hand by the internal pressure of the container and on the other hand a return spring for the valve element can also be provided.

An embodiment of the invention is particularly preferred in which the opening cross-section that opens first when the valve element is actuated is smaller than the at least one further opening cross-section. In addition to the conceivable successive release of several opening cross-sections of the same or similar size, it is also possible through the aforementioned pressure equalization and the onset of flow of the viscous substance to provide a correspondingly enlarged second or further opening cross-section in order to quickly open a large opening cross-section for dispensing the substance To have available.

When the valve is open, the opening cross section can have the shape of an annular gap, for example, preferably in the area of at least one opening cross section ring-shaped sealing element to release the opening cross-section movable closing element can be raised substantially axially relative to the sealing element. Such a solution offers the advantage that the seals are not subjected to sliding movements in the area of their sealing surface, but only to a pressure caused by the closing element which is applied. This means that the choice of material for the sealing element is considerably less critical, since any swelling of a certain material that occurs is only to a lesser extent disadvantageous for the sealing effect and has no influence on the actuating forces. Wear of the sealing surfaces due to repeated opening processes is hardly to be feared.

The sealing elements can in principle be provided on one or on both parts which are moved relative to one another in the region of an opening cross section. For example, the closing element, i. H. the moving part itself carries the sealing element or can be formed by a coating as a sealing element. In view of the viscous substances, it is usually advisable that the sealing element has a cross-sectional shape with a flat ring contact surface or a defined sealing contour for the closing element, since line-shaped seals may not meet the requirement for permanent gas tightness, since residues of the substance between the sealing element and fix the locking element.

An embodiment in which the opening cross sections are concentric with one another is also particularly expedient. The closing element of the first opening cross section is preferably arranged directly at the end of the movable valve element facing the interior of the container. In a preferred development, the valve element can be hollow and form the outlet opening or nozzle for the substance stored in the container. Such a valve element can be made in one piece particularly inexpensively, for example from plastic. In order to carry out the axial movements of the connected first closing element, the valve element can be guided in an axially movable manner in a valve housing, which is pressure-tightly connected to a housing of the pressure container, or rotatably seated in the valve housing via a threaded connection. In both cases, the return springs already mentioned can be provided in a suitable design. Examples of such spring elements are conventional standard springs or elements made of rubber or elastic plastics. The opening cross sections are then released by axially pressing in the valve element or rotating the valve element in the thread relative to the valve housing.

In the case of an axially movable valve element, an actuating element can be useful which is connected to the movable valve element via a translation. As a result, the actuating forces can be reduced further, the actuating element being designed as a lever in a particularly preferred embodiment, which is articulated on the valve element and on the valve housing.

A particularly simple construction is achieved in a further preferred embodiment of the invention. by the fact that the sealing element of the first opening cross section is arranged on the closing element of the second sealing point,

In this embodiment, the closing element of the second opening cross section forms a movable intermediate element which, in a further preferred embodiment, can be taken along by a driver provided on the valve element to release the second opening cross section after the first opening cross section has been released. In this way, a functionally reliable dispensing valve can be constructed with very few components.

The formation of the driver is expediently star-shaped with three or more arms, the second closing element having a central opening through which the valve element projects with its first closing element. The driver is, of course, larger than the central opening and, after a certain opening path of the valve element, rests against the second closing element and takes it into a position that releases the second opening cross section. A design of the second closing element as a disk, cone or plate-shaped ring is particularly preferred, the first sealing element being arranged in the region of the central opening. Such a configuration of the second closing element is very space-saving, the first sealing point having the first opening cross section being defined in the region of the central opening of the second closing element and the second sealing point having the second opening cross section being defined on the outer edge of the second closing element. A guide can be provided which axially guides the second closing element and / or secures it against tipping in order to avoid that the relative position Change the sealing elements to the closing elements, which could impair the sealing effect.

In a further preferred embodiment of the invention it is provided that the valve housing is made of plastic and a hold-down device is provided for the pressure-tight connection to the container, which is flanged over an annular flange of the valve housing and an upper end of the container. The use of the hold-down device makes it possible to connect the plastic body of the valve housing in a pressure-tight manner to the container, which generally consists of sheet metal, or its upper end, the so-called top. The sealing ring is preferably located between the upper end of the top and the underside of the ring flange made of plastic, it being particularly preferred to use a sealing ring designed as an annular disk which, in the initial state, projects radially beyond the ring flange of the valve housing before being attached to the container. It has been shown that a particularly good sealing effect is achieved in this way, in particular if, owing to the flanging, the sealing ring comes directly between the hold-down device and the sheet metal part of the container.

An exemplary embodiment of the invention is explained in more detail below with reference to the accompanying drawing. Show it:

1 shows a longitudinal section of a pressure container in the valve area;

2 shows a detailed view of the transition area between the valve and the container. Fig. 1 shows a longitudinal section of a pressure container 10, which is provided for receiving a viscous substance under pressure, in particular frozen substances, such as. B. ice cream. The walls 12 of the container can consist of sheet metal or aluminum, and an outlet valve 14 is arranged in a pressure-tight manner in an opening in the wall 12, which will be discussed in more detail later in connection with FIG. 2.

The outlet valve 14 has a valve housing 16 which is connected to the container wall 12 in a pressure-tight manner and in which a valve element 18 is movably guided against the force of a return spring 20. For this purpose, the valve housing 16 has an inner bore 22, the diameter of which essentially corresponds to the outer diameter of the hollow cylindrical valve element 18. The return spring 20 is arranged between a shoulder 24 on the outer circumference of the valve element 18 and a step 26 in the inner bore 22 of the valve housing 16. A sealing ring 28 in the foot region of the inner bore 22 seals the space between the valve element 18 and the valve housing 16 against the penetration of the viscous substance, with no significant pressurization to be expected in this region.

A piston-like first closing element 30 is formed on the end of the valve element 18 facing the interior of the container and forms a first sealing point with a first sealing element 32 arranged on an intermediate element or second closing element 34. An axial gap-shaped, relatively small opening cross section can be released by the axial movement of the piston 30 relative to the intermediate element 34, which will be discussed in more detail later. The piston-shaped first Closing element 30 is rigidly connected to the wall 40 of the valve element 18 via a tappet 36 with an axial alignment and radial webs 38 provided at the end thereof. The spaces between the radial webs allow the material to pass through the hollow valve element 18, which forms a nozzle, it being possible for the free end 42 of the valve element to have a jagged shape.

The intermediate element 34 has a plate-like ring shape and at the same time fulfills the function of a second closing element 34 which, in cooperation with a sealing element 44 provided on the end face of the housing interior on the valve housing 16, forms a second sealing point, an annular gap-shaped second opening cross section being releasable when the second closing element 34 moves axially which is considerably larger than the first opening cross section in the area of the first sealing point. The second closing element 34 is carried along with the aid of a star-shaped driver 46, the circumference of its webs being greater than the inner diameter of the bore of the plate-shaped second one

Closing element 34 is, so that the latter can be taken along when the valve element 28 is axially displaced by the star-shaped webs of the driver. The spaces between the webs of the driver 46 allow the material to pass through the material flowing out through the first opening cross section.

The cross section of the ring-shaped sealing elements 32, 44 in the region of the two sealing points is such that the respective closing elements 30, 34 lie flat against one another in order to achieve a pressure-tight seal that is as permanent as possible when residues of the substance stored in the container 10 sit between the sealing element and the closing element.

To actuate the outlet valve 14, an actuating lever 48 is provided, which is articulated on the one hand at an articulation point 50 on the valve housing 16 and on the other hand at a second articulation point 52 on the valve element 18. The resulting translation reduces the actuation forces required for the opening movement of the valve element 18.

The actuation process is such that when the actuation lever 48 is depressed, the valve element 18 is displaced toward the interior of the container while the return spring 20 is further pretensioned. The inclined circumferential surface of the piston-like, conical first closing element 30 stands out from the sealing element 32, which sits on the edge of an inner bore of the second closing element 34, since the first closing element 30 has only a very small end face, the resistance when depressed relatively low, whereby in addition to the internal pressure of the container, which is usually about 10 bar, the viscosity of the substance and in particular also the formation of ice in the case of deep-frozen substances opposes the movement of the valve element to a considerably higher resistance than is the case with normal aerosols ,

The release of the annular gap-shaped first opening cross-section ensures by the raising of the first closing member 30 of the first sealing element 32 to it that a certain pressure is carried balancing on both sides of the second closing element 34 and the structure of the stored substance in particular ^¬ sondere in the frozen state by the incipient currents loosening movement through the first opening cross section. However, the emerging volume flow is still very small due to the overall very small cross-sectional area in the area of the first sealing point. When the actuating lever 48 is depressed further, the driver 46 comes into abutment with the second closing element 34 and axially entrains it when it is depressed further. As already mentioned, due to the pressure equalization that has already occurred and the onset of the flow movement, the actuation force required for this is considerably less than if the valve element 18 were rigidly connected to the second closing element 34 and an opening cross section had not previously been released.

As soon as the valve element 18 has reached its depressed end position, the viscous mass can flow out of the interior of the container due to the pressure existing there through the first annular-shaped opening cross-section in the area of the first sealing point and through the larger second annular-shaped opening cross-section in the area of the second sealing point. so that a desired volume flow results with an inflow of mass into the entire nozzle area in the valve element 18.

After the actuation lever 48 is released, the valve element 18 is displaced again in the direction of its closed starting position under the action of the return spring 20, the closing process also being supported by the system pressure.

Only the sealing elements 32, 44 in the area of the sealing points must be pressure-tight in order to be able to withstand the system pressure permanently, while the sealing ring 28 - In ¬

can be designed as a simple O-ring between the valve housing 16 and the valve element 18.

Of course, various modifications of the embodiment shown are conceivable. For example, the valve element 18 can also be guided movably via a thread in the valve housing 16, in which case an actuating element sets the valve element 18 in rotation and the thread pitch forms the translation in order to increase the initial resistance when the first closing element 30 is lifted off the first sealing element 32 overcome. In such an embodiment, a torsion spring can be arranged to reset the valve element 18. It is also conceivable not to provide the sealing element 32 directly on the second closing element 34, but rather on the first closing element 30. In the area of the first opening cross section, the second closing element 32 then merely forms a contact surface for the sealing element moved with the first closing element 32. The second closing element 32 can also have the shape of an annular disk or a simple cone, solid closing elements 34 of greater thickness also being conceivable, which can then also be manufactured, for example, as a plastic injection-molded part. The closing element 32 can also hold the second sealing element 44 of the second opening cross-section, only a correspondingly suitable contact surface then having to be provided on the valve housing. It is conceivable, for. B. also a completely or partially covered with sealing material closing element that forms sealing elements for both opening cross sections. It is also conceivable to provide guide elements in the region of the first closing element or on the end face of the valve housing 16, which elements ensure secure axial guidance of the second closing element 34 and / or for securing against tilting of the second closing element 34 can ensure to ensure an exact contact of the closing elements with the sealing elements.

FIG. 2 shows a detailed view of the area in which the valve housing 16 is connected to an upper part 51 of the container 12, the so-called top. The valve housing 16 has an annular flange 53 which is designed with its outer end curved slightly downward. A hold-down device 54 seated on the circumferential surface of the valve housing 16 is flanged around the ring flange 53 and around an upper bent end 56 of the top 51, a disk-shaped sealing ring 58 lying between the end 56 and the underside of the ring flange 53 being clamped in such a way that he also fills the gap between the end 56 and the hold-down 54 itself. In this way, a pressure-tight connection between the valve housing 16 made of plastic and the top 51 made of sheet metal is created, which is connected in a known manner pressure-tightly to a wall of the container 12 with its lower, radially outer end shown in FIG. 2 ,

In the initial state, i.e. H. Before the valve is installed in a pressure-tight manner in the opening of the container, the hold-down 54 with an essentially L-shaped cross section sits on the

Valve housing 16 and also the sealing ring 58 are arranged on the underside of the flange 52 on the valve housing 16. A catch in the area of the valve housing 16 can provide that the hold-down device 54 is held captively on the valve housing 16 in the initial state.

Claims

claims

1. Pressure container for receiving viscous substances with an outlet valve (14) which is adjustable between a closed position and an open position, a movable valve element (18, 30) being movable in the direction of the interior of the container to release an opening cross section, characterized in that at least two opening cross-sections are provided, with operation of the valve (14) first releasing a first opening cross-section and subsequently at least one further opening cross-section.

2. Pressure vessel according to claim 1, characterized in that the first opening cross-section which opens when the valve (14) is actuated is smaller than the at least one further opening cross-section.

3. Pressure container according to claim 1 or 2, characterized in that when the valve (14) is open, at least one opening cross-section has the shape of an annular gap.

4. Pressure vessel according to one of claims 1 to 3, characterized in that the first opening cross section is defined by a first sealing element (32) and a first closing element (30) and the second opening cross section by a further sealing element (44) and a further closing element ( 34) is defined.

5. Pressure container according to claim 3, characterized in that in the region of at least one opening cross-section closing element (30, 34) movable relative to the ring-shaped sealing element (32, 44) to release the opening cross section can be lifted substantially axially relative to the sealing element (32, 44).

6. Pressure container according to claim 5, characterized in that the sealing element (32, 44) has a cross-sectional shape with a flat ring contact surface or a specific sealing contour for the associated closing element (30, 34).

7. Pressure container according to one of claims 3 to 6, characterized in that the opening cross sections are concentric with one another.

8th . Pressure container according to one of the preceding claims, characterized in that the closing element (30) of the first opening cross-section is arranged on the end of the movable valve element (18) facing the interior of the container.

9. Pressure container according to one of the preceding claims, characterized in that the sealing element (32) of the first opening cross section is arranged on the closing element (34) of the second opening cross section.

10. Pressure container according to one of the preceding claims, characterized in that on the valve element (18) a driver (46) is provided which takes the second closing element (34) to release the second opening cross-section after the release of the first opening cross-section.

11. Pressure container according to claim 10, characterized in that the driver is star-shaped with three or more arms and the second closing element (34) has a central opening.

12. Pressure container according to claim 11, characterized in that the second closing element (34) is designed as a disc, conical or plate-shaped ring, the first sealing element (32) on the inside of the container (10) facing the side of the closing element ( 34) is arranged around the central opening.

13. Pressure container according to claim 12, characterized in that a guide is provided which axially guides the second closing element (34) and / or secures it against tipping.

14. Pressure container according to one of the preceding claims, characterized in that the valve element (18) is hollow and forms the outlet opening for the substance stored in the container (10).

15. Pressure container according to one of the preceding claims, characterized in that the valve element (18) is movably guided in a valve housing (16) which is pressure-tightly connected to a housing (12) of the pressure container (10).

16. Pressure container according to claim 15, characterized in that a return spring (20) biases the valve element (18) in the direction of its closed position.

17. Pressure container according to one of the preceding claims, characterized in that an actuating element (48) is provided which is connected via a translation (50, 52) to the movable valve element (18).

18. Pressure vessel according to claim 17, characterized in that the actuating element is designed as a lever (48) which is connected to the valve element (18) and the valve housing (16) via articulation points (50, 52).

19. Pressure vessel according to one of claims 1 to 16, characterized in that the valve element is rotatably mounted in the valve housing via a thread and, if appropriate, a torsion spring is provided as a return spring.

20. Pressure vessel according to one of claims 15 to 19, characterized in that the valve housing 16 is made of plastic and a hold-down device is provided for the pressure-tight connection to the container (12), which is around an annular flange of the valve housing (16) and an upper end of the Container (12) is crimped.

21. Pressure container according to claim 20, characterized in that a sealing ring is provided between the upper end of the container (12) and the underside of the ring flange.

22. Pressure container according to claim 21, characterized in that the sealing ring is designed as an annular disc and in the initial state before being attached to the container (12) protrudes radially beyond the annular flange of the valve housing.