EP1474344B1 - Pressure container for viscous substances - Google Patents

Description

The present invention relates to a pressure vessel for receiving viscous substances with an outlet valve which is adjustable between a closed position and an open position, the pressure vessel having the features of the preamble of claim 1.

A particular problem with higher viscous substances to be stored in handy pressure vessels similar to known Aerosolsprühdosen, is that a relatively large opening cross section in the open state of the exhaust valve must be provided in order to achieve a satisfactory release of the substance after actuation of the valve. 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 for releasing the opening cross-section then has to have a correspondingly large area, whereby the force for actuating the exhaust valve increases in an impracticable manner. This problem is aggravated even with deep-frozen pressure vessels and the resulting ice formation, which can further increase the necessary opening force.

Alternatively, a rotary valve is already known from EP 1 167 842, in which the penetration of a part of the valve element into the interior of the container when moving into the open position is avoided. Difficulties exist here in the field of sealing, since the sealing material must be loaded to achieve a permanent sealing effect with a certain pressure, wherein the volume of the sealing material can change by swelling under the action of stored substance in the container. As a result, the seal can either be damaged or the actuation forces can increase very strongly, as a result of which the valve can become stuck. A permanent gas-tightness and the fulfillment of, for example, foodstuffs regulations in the storage of food in the pressure vessel are further natural requirements. A pressure vessel of the type mentioned is already known from US-A-3, 231, 153.

The object of the present invention is to provide a pressure vessel for receiving viscous substances in the frozen state, the exhaust valve works permanently reliable.

According to the invention the object is achieved in that a pressure vessel of the type described above, further comprising the features of the characterizing part of claim 1.

The pressure vessel according to the invention has the advantage that at first correspondingly smaller actuating forces only a small cross-section is released, ie it is displaced only a small volume by the penetrating into the container interior valve element. After opening the first cross-section, the viscous mass can flow at comparatively low throughput already in the outlet, so that in the region of the sealing points a certain pressure equalization is created and also by the onset of outflow movement, the structure of the substance is loosened, so that at comparatively lower Operating force by further actuation of the valve element and the second opening cross-section can be released and subsequently the substance can flow through the large total cross-section. In this way, on the one hand, the actuating forces are reduced to open the valve and on the other hand, the required for discharging a certain volume per unit time opening cross-section is still possible.

The closing process is analogously reversed, the closing movement is supported on the one hand by the internal pressure of the container and on the other hand, a Rücltstellfeder may be provided for the valve element.

The sealing elements may in principle be provided on one or both relatively moving parts in the region of an opening cross-section. Thus, for example, the closing element, d. H. the moving part itself carry the sealing element or be formed by a coating as a sealing element. In view of the viscous substances, it is generally expedient 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 linear seals may not meet the requirement of a permanent gas tightness, as residues of the substance between the sealing element and set the closing element.

A structurally particularly simple structure is achieved in a further preferred embodiment of the invention in 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 carried along by a driver provided on the valve element for releasing the second opening cross section after the release of the first opening cross section. In this way, a functionally reliable dispensing valve can be built with very few components.

Particularly preferred is an embodiment of the invention, in which the first opening opening cross section 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 by the aforementioned pressure equalization and the incipient flow of the viscous substance to provide a correspondingly enlarged second or wider opening cross-section to quickly as possible a large opening cross section for the application of the substance To have available.

The opening cross-section may have, for example, the shape of an annular gap when the valve is open, wherein preferably in the region of at least one opening cross-section, the closing element movable from the annular sealing element to release the opening cross-section can be raised substantially axially relative to the sealing element. Such a solution has the advantage that the seals are not claimed with sliding movements in the region of their sealing surface, but only to a pressure by the abutting closing element. This means that the choice of material for the sealing element is much less critical, possibly because occurring swelling of a given material are only to a lesser extent disadvantageous for the sealing effect and without influence on the actuating forces. A wear of the sealing surfaces by repeated opening operations is hardly to be feared.

Also particularly useful is an embodiment in which the opening cross-sections are concentric with each other.

In a preferred embodiment, the valve element may be hollow and form the outlet opening or nozzle for the substance stored in the container. Such a valve element may be made in one piece particularly cost-effective example of plastic. In order to carry out the axial movements of the connected first closing element, the valve element in a valve housing which is pressure-tightly connected to a housing of the pressure vessel, be guided axially movable or rotatably via a threaded connection in the valve housing. In both cases, the already mentioned return springs may be provided in each case suitable design. Examples of such spring elements are conventional standard springs or elements of rubber or elastic plastics. The release of the opening cross-sections is then carried out by axially pressing the valve element or twisting of the valve element in the thread relative to the valve housing.

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

Suitably, the training of the driver is star-shaped with three or more arms, wherein the second closing element has a central opening through which the valve element protrudes with its first closing element. The driver is of course designed to be larger than the central opening and, after a certain opening travel of the valve element, bears against the second closing element and carries it into a position which releases the second opening cross-section. Particularly preferred is a design of the second closing element as a disk, cone or plate-shaped ring, wherein the first sealing element is arranged in the region of the central opening. Such a design of the second closing element is very space-saving, wherein the first sealing point is defined with the first opening cross section in the region of the central opening of the second closing element and the second sealing point with the second opening cross section at the outer edge of the second closing element. A guide can be provided which axially guides the second closing element and / or secures against tilting, in order to avoid that the relative positions change the sealing elements to the closing elements, whereby the sealing effect could be impaired.

In a further preferred embodiment of the invention, it is provided that the valve housing is made of plastic and a hold-down is provided for pressure-tight connection with the container, which is flanged around an annular flange of the valve housing and an upper end of the container. The use of the hold-down makes it possible to connect the plastic body of the valve housing pressure-tight with the usually made of sheet metal container or its upper end, the so-called. Top. The sealing ring is preferably located between the upper end of the top and the bottom of the annular flange made of plastic, wherein it is particularly preferred to use a designed as an annular disc sealing ring which protrudes in the initial state before attaching to the container radially over the annular flange of the valve housing. It has been found that in this way a particularly good sealing effect is achieved, in particular when passes as a result of Umbördelns the sealing ring directly between the hold-down and the sheet metal part of the container.

Fig. 1

einen Längsschnitt eines Druckbehältnisses im Ventilbereich;

Fig. 2

eine Detailansicht des Übergangsbereiches zwischen dem Ventil und dem Behältnis.

In the following, reference will be made to an embodiment of the invention with reference to the accompanying drawings. Show it:

Fig. 1

a longitudinal section of a pressure vessel in the valve area;

Fig. 2

a detailed view of the transition region between the valve and the container.

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

The outlet valve 14 has a valve housing 16 which is pressure-tightly connected to the container wall 12 and in which a valve member 18 is movably guided against the force of a return spring 20. For this purpose, the valve housing 16 has an inner bore 22 whose diameter substantially 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, which is not to be expected in this area with a significant pressurization.

At the end of the valve element 18 facing the container interior, a piston-like first closing element 30 is formed, which forms a first sealing point with a first sealing element 32 arranged on an intermediate element or second closing element 34. By axial movement of the piston 30 relative to the intermediate member 34 is an annular gap-shaped, relatively small opening cross-section can be released, which will be discussed later in more detail. The piston-shaped first Closing element 30 is connected via a plunger 36 axial alignment and provided at the end of radial webs 38 with gaps with the wall 40 of the valve element 18 is rigidly connected. The spaces between the radial webs allow the passage of material through the hollow, a nozzle forming valve element 18, wherein the free end 42 of the valve element may be formed jagged.

The intermediate element 34 has a plate-like ring shape and simultaneously fulfills the function of a second closing element 34, which forms a second sealing point in cooperation with a front side of the housing interior to the valve housing 16 provided sealing element 44, wherein at axial movement of the second closing element 34 an annular gap-shaped second opening cross-section releasable is, which is considerably larger than the first opening cross-section in the region of the first sealing point. The entrainment of the second closing element 34 takes place with the aid of a star-shaped driver 46, wherein the periphery of the webs is greater than the inner diameter of the bore of the plate-ring-shaped second closing element 34, so that the latter is entrained by the star-shaped webs of the driver in axial displacement of the valve element 28. The spaces between the webs of the driver 46 allow the material passage of the material flowing through the first opening cross-section material.

The annular sealing elements 32, 44 in the region of the two sealing points are each such in their cross-section that results in a two-dimensional contact of the respective closing elements 30, 34 in order to achieve a permanent pressure-tight seal even if Remains of the substance stored in the container 10 put between the sealing element and the closing element.

For actuating the exhaust valve 14, an actuating lever 48 is provided which is articulated on the one hand at a hinge point 50 on the valve housing 16 and on the other hand at a second hinge point 52 on the valve element 18. The consequent translation reduces the necessary for the opening movement of the valve element 18 actuation forces.

The actuation process takes place so that upon depression of the actuating lever 48, the valve element 18 is displaced under further bias of the return spring 20 to the container interior. In this case, the inclined aligned circumferential surface of the piston-like, conical first closing element 30 lifts off from the sealing element 32, which sits at 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 during depression is relatively low, wherein in addition to the internal pressure of the container, which is usually about 10 bar, and the viscosity of the substance and in particular the formation of ice in frozen substances of the Movement of the valve element opposes a much higher resistance than is the case with normal aerosols.

The release of the annular gap-shaped first opening cross-section by the lifting of the first closing element 30 of the first sealing element 32 ensures that a certain pressure equalization takes place on both sides of the second closing element 34 and the structure of the stored substance, in particular in the frozen state by the incipient flow movement loosens through the first opening cross-section. However, due to the overall relatively small cross-sectional area in the region of the first sealing point, the outflowing volume flow is still very small. When depressed further operating lever 48, the driver 46 comes into abutment with the second closing element 34 and takes this axially with further depression. As already mentioned, due to the already occurring pressure equalization and the onset of flow movement, the actuating force required for this purpose is substantially lower than when the valve element 18 is rigidly connected to the second closing element 34 and not previously an opening cross-section would have been released.

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

After releasing the operating lever 48, the valve member 18 is displaced under the action of the return spring 20 again in the direction of its closed starting position, wherein the closing operation is also supported by the system pressure.

Only the sealing elements 32, 44 in the region of the sealing points must be pressure-tight in order to be able to withstand the system pressure permanently, while the sealing ring 28 between the valve housing 16 and the valve element 18 may be designed as a simple O-ring.

Of course, various modifications of the embodiment shown are conceivable. Thus, for example, the valve element 18 can also be movably guided 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 ratio to the initial resistance when lifting the first closing element 30 from the first sealing element 32 overcome. In such an embodiment, a torsion spring for returning the valve element 18 may be arranged. It is also conceivable not to provide the sealing element 32 directly on the second closing element 34 but on the first closing element 30. The second closing element 32 then forms in the region of the first opening cross-section only a contact surface for the moving with the first closing element 32 sealing element. The second closing element 32 may also have the form of an annular disk or a simple cone, wherein also solid designed Schlie ß elements 34 of greater thickness are conceivable, which can then be made 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, wherein then only a correspondingly suitable contact surface must be provided on the valve housing. It is conceivable z. As well as a completely or partially coated with sealing material closing element that forms sealing elements for both opening cross-sections. It is also conceivable to provide 16 guide elements in the region of the first closing element or on the front side of the valve housing, for a secure axial guidance of the second closing element 34 and / or for a safeguard against tilting of the second closing element 34 can provide to ensure an exact contact of the closing elements on the sealing elements.

FIG. 2 shows a detailed view of the region 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 bent slightly downwards. A seated on the peripheral surface of the valve housing 16 hold-down 54 is crimped around the annular flange 53 and an upper bent end 56 of the top 51, wherein between the end 56 and the bottom of the annular flange 53 lying disc-shaped sealing ring 58 is clamped so that he also fills the gap between the termination 56 and the hold-down 54 itself. In this way, a pressure-tight connection between the existing plastic valve housing 16 and the top 51 consisting of sheet metal is created, which is connected in a pressure-tight manner with its shown in Fig. 2 lower, radially outer end in a known manner with a wall of the container 12 ,

In the initial state, d. H. before the pressure-tight mounting of the valve in the opening of the container, the hold-down 54 sits with a substantially L-shaped cross-section on the valve housing 16 and also the sealing ring 58 is disposed on the underside of the flange 52 on the valve housing 16. A catch in the region of the valve housing 16 may provide that the hold-down device 54 is held captive on the valve housing 16 in the initial state.

Claims (10)

1. A pressure vessel for accommodating viscous substances, having 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 inside of the vessel to open up first of all a first opening cross-section and subsequently at least one further opening cross-section through actuation of the valve (14), the first opening cross-section being defined by a first sealing element (32) and a first closing element (30) and the second opening cross-section comprising a second closing element (34) and the closing element (30) of the first opening cross-section being arranged at the end of the movable valve element (18) facing the inside of the vessel, characterised in that a second sealing element (44) is provided for the second opening cross-section and the sealing element (32) of the first opening cross-section is arranged on the closing element (30) of the first opening cross-section or on the closing element (34) of the second opening cross-section, wherein a driver (46) is provided on the valve element (18), which driver drives the second closing element (34) to open up the second opening cross-section after opening up of the first opening cross-section.
2. A pressure vessel according to claim 1, characterised in that the first opening cross-section opening first of all on actuation of the valve (14) is smaller than the at least one further opening cross-section.
3. A pressure vessel according to claim 1 or claim 2, characterised in that, when the valve (14) is open, at least one opening cross-section takes the form of an annular gap, wherein the opening cross-sections are preferably positioned concentrically to one another.
4. A pressure vessel according to claim 3, characterised in that, in the area of at least one opening cross-section, the closing element (30, 34), movable relative to the sealing element (32, 44) of annular construction to open up the opening cross-section, may be raised substantially axially relative to the sealing element (32, 44), wherein the sealing element (32, 44) preferably exhibits a cross-sectional shape with a flat annular seating face or a predetermined sealing contour for the associated closing element (30, 34).
5. A pressure vessel according to any one of the preceding claims, characterised in that the driver (46) is of star-shaped construction with three or more arms.
6. A pressure vessel according to claim 5, characterised in that the second closing element (34) comprises a central opening and is constructed as a disc-shaped, conical or dished ring, wherein the first sealing element (32) is arranged around the central opening on the side of the second closing element (34) facing the inside of the vessel (10), wherein a guide is provided, which guides the second closing element (34) axially and/or secures it against tilting.
7. A pressure vessel according to any one of the preceding claims, characterised in that the valve element (18) is of hollow construction and forms the outlet opening for the substance stored in the vessel (10).
8. A pressure vessel according to any one of the preceding claims, characterised in that the valve element (18) is guided movably in a valve housing (16), which is connected in pressure-tight manner to a housing (12) of the pressure vessel (10), wherein a restoring spring (20) preferably pretensions the valve element (18) in the direction of its closed position.
9. A pressure vessel according to any one of the preceding claims, characterised in that an actuating element (48) is provided, which is connected to the movable valve element (18) via a transmission gear (50, 52), e.g. by constructing the actuating element as a lever (48) which is connected with the valve element (18) and the valve housing (16) via articulation points (50, 52), or in that the valve element is mounted rotatably via a thread in the valve housing and a torsion spring is optionally provided as restoring spring.
10. A pressure vessel according to claim 8 or claim 9, characterised in that the valve housing (16) consists of plastics material and a hold-down member is provided for pressure-tight connection with the vessel (12), which hold-down member is flanged around an annular flange of the valve housing (16) and an upper terminating element of the vessel (12), wherein a sealing ring is provided between the upper terminating element of the vessel (12) and the underside of the annular flange, said sealing ring taking the form of an annular disc and projecting radially beyond the annular flange of the valve housing in the initial state prior to attachment to the vessel (12).

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