EP3668802B1 - Solid matter valve for pressurized cans - Google Patents

Description

The invention relates to a solid matter valve for pressure cans, in particular for the application of assembly foams, with a valve plate, a valve body arranged in the valve plate, a stem mounted in a central recess of the valve body with at least one inlet opening for the pressure can contents that can be released by actuating the stem, at least one Outlet opening, a channel connecting the inlet opening to the outlet opening, at least one sealing element acting between the valve body and the stem, and a spring element.

Solids valves can be used in particular for the application of assembly and sealing foams from aerosol cans, but are basically suitable for all forms of aerosol cans from which materials with a solid content are applied, for example also for the application of paint, adhesive, sealants and cleaning agents. A valve for an aerosol can is for example in document GB1446858 disclosed. Assembly foams, in particular polyurethane foams, have found a large area of application in technology. In the construction sector, they are used to fasten elements such as window frames, door frames and other prefabricated parts, to close openings and to fill cavities and pockets with foam. They are widely used for heat and sound insulation. They are also suitable for avoiding condensation with subsequent corrosion in cavities filled with them.

For the formation of foam, prepolymers contained in the container are mostly used, which frequently harden through the action of moisture, in particular atmospheric moisture. After the mixture of blowing agent and foaming agent has been released, a reaction takes place between the prepolymer and the humidity in the air. This leads to the formation of a permanent foam. Depending on the moisture content of the air, curing takes place in a more or less short time. Curing only takes a few minutes at high humidity. Two-component foams also contain a separate crosslinking component in the pressurized can.

Special valves are used to discharge or discharge the foam, which by tilting or pushing open the path of the foam. On the other hand, they must ensure a secure seal during transport and interim storage. If the seal is insufficient, moisture diffuses into the valve mechanism, which causes the prepolymers to harden in the valve, which impairs its proper function. In the extreme case, the valve is completely blocked by the polymer formed in it.

Since the internal pressure of the pressure vessel is usually not sufficient to bring about a complete return of the valve after triggering, spring elements are used. Disc valves are known in which the valve closure element is connected to a holding part as an abutment via a helical spring. The holding part protrudes freely into the inner part of the pressure vessel. The spring is inserted between the holding part and the valve closure element and ensures that it is firmly seated on the valve plate. One problem with the use of coil springs is that their function can be impaired or blocked by deposits.

Another problem with conventional poppet valves is the sealing in the area of the stem. The stem is movably arranged within the valve body, the tightness mostly being brought about by sealing lips. Here too, deposits can occur that impair the proper sealing function.

The object of the invention is therefore to provide a valve which avoids the disadvantages of conventional valves described above. It should protect against the ingress of moisture into the valve area in the pressure vessel. At the same time, however, it must also be possible to connect application aids such as spray guns. It should have a simple structure and ensure a high level of operational reliability. In particular, such a valve should also have a less susceptible spring mechanism.

To solve this problem, the invention proposes, starting from a valve of the type mentioned at the outset, designing the stem in two parts, the upper part having the at least one outlet opening and being integrally connected to the valve body via a circumferential elastic membrane and the lower part the at least one Has inlet opening, wherein the lower and upper part of the stem are positively and / or non-positively connected to one another.

The terms "can side" and "valve side", as they are used in the description and in the claims, denote, in an orientation along the central axis of a pressurized can, the end of a part facing the pressurized can (can-side) and that from the can in End of a part pointing out towards the valve (valve side).

The solids valve according to the invention for pressurized cans has a conventional valve disk which has a circular central recess. The valve disk usually has one between the recess and the outer edge Tub-shaped profile with a raised inner edge on which the valve body is fixed.

The valve body itself can be molded onto the valve disk in a manner known per se, i.e. the raised inner edge of the valve disk is located inside the valve body. Alternatively and here preferred is an embodiment in which the valve body is adapted to the shape of the valve disk, has a rising edge which engages with an outwardly pointing projection over the inner edge of the valve disk. Such a valve body is pressed into the valve disk from the underside.

At the same time, the valve body has an outward-facing area which accommodates the can-side contour of the valve disk and clings closely to it. The protrusion pointing outwards and reaching over the inner edge of the valve disk secures the valve body on the valve disk. The internal pressure of the pressure cell ensures a high contact pressure and tightness in this area.

It can be expedient to equip the valve body in the contact area with the valve disk with concentrically encircling sealing lips which produce an additional seal.

The valve body has a central recess in which the stem of the valve is mounted so that it can move vertically. On the can side, the stem has at least one inlet opening for the can contents, on the valve side at least one outlet opening through which the can contents can exit after the valve has been actuated.

According to the invention, the stem is divided into an upper and a lower part. Both parts are connected to one another in a form-fitting and / or force-fitting manner. The lower, can-side part of the stem has the inlet opening, the upper, valve-side part of the outlet opening, the openings being connected to one another by a channel.

According to the invention, the upper part of the stem is integrally connected to the valve body via a membrane. Integrally connected means that the valve body and the upper part of the stem are formed in one piece, with a concentrically formed membrane producing the connection between the two parts. Such a construction can easily be produced by injection molding. This ensures that the narrow gap between the valve body and stem, which ensures the mobility of the stem, is closed on the valve side; it is not possible for the contents of the can to escape when the valve is open or closed.

The elastic membrane preferably runs along the valve-side edge of the lower part of the stem. The membrane can be designed step-like, i.e. designed in waves. This creates a reserve area that allows the stem to move without the membrane being placed under excessive tension. Between the upper edge of the valve body and the elastic membrane there runs a concentrically encircling depression which contributes to the elasticity and area reserve of the membrane. In addition, this prevents the movement of the stem from being transmitted directly to the upper edge of the valve body, which is important for fixing and sealing the valve body. The geometry and strength of the membrane create the elasticity.

When the valve is actuated, the stem is pressed in vertically in order to dispense the contents of the can - mostly using an application aid or a spray gun - the stem taking along the membrane as it moves downwards. This leads to a change in the contour, which exerts a certain tension and is absorbed by the elasticity. If the membrane is stepped, this movement and tension is absorbed in the step area.

The two parts of the stem are positively and / or non-positively connected to one another. This means that they function as a unit and are firmly connected to each other. The two parts have a central channel for discharging the contents of the can.

In particular, the channel of the lower part of the stem has a central receptacle in the valve-side region, into which the socket-side end of the upper part of the stem is fitted. For this purpose, a circumferential extension can be arranged in the area of the receptacle of the lower part, into which an externally circumferential bead of the upper part engages in a form-fitting manner. A sealing element is located between the valve body and the lower part of the stem. This is preferably a sealing lip which runs around the valve body on the can side and which cooperates with a circumferential projection on the lower part of the stem. When the valve is closed, this sealing lip closes reliably against the projection, but opens up a passage for the contents of the can as soon as the stem is triggered downwards.

As already mentioned, the solids valve according to the invention needs a spring element for a perfect closing function. For this purpose, the valve body preferably has an extension on the socket side which surrounds the lower part of the stem and serves as a holding element for the spring element. This extension, which concentrically surrounds the lower part of the stem, also increases the stability and rigidity of the valve body.

The spring element can consist of a conventional helical spring which is mounted in a spring cage, which in turn is arranged on the extension of the valve body. However, the spring element is preferably a spring clip which is fixed to the valve body by means of holding arms. For this purpose, these holding arms engage in recesses in the extension of the valve body, be it through ends of the arms bent in the direction of the valve body or through Notched retaining tongues which engage in the recesses and which, in addition to the blocking effect, also exert a spring effect at the same time.

The spring clip itself is preferably arched in the direction of the valve and has a dent or recess in the center in the area of the arch, into which a projection of the lower part of the stem engages. This measure serves to center the stem, which is held in this way in the center of the interior of the valve body.

The upper part of the stem preferably has a sealing sleeve which is made of an elastic material, for example a thermoplastic elastomer, and is suitable for producing the sealing seat for a foaming gun. This sealing grommet is limited on the valve side by a fixing ring which, in contrast, is made of a hard material, such as a polyoxymethylene, and serves as an abutment for the trigger of the foaming gun. The fixing ring and sealing collar are expediently connected to one another in a form-fitting manner, for example in such a way that the fixing ring has a circumferential groove on the can side, into which a circumferential projection of the sealing collar engages. At the same time, the fixing ring and / or sealing collar are fitted into a recess in the upper part of the stem so that there is a firm connection. In addition or at the same time, the fixing ring can be fixed by means of a press fit on the valve-side end of the upper part of the stem.

The valve body is made in the usual way from a thermoplastic material, for example from a polyalkylene, in particular polyethylene or polypropylene.

Fig. 1:

Eine Schnittzeichnung des erfindungsgemäßen Ventils in einem Ventilteller;

Fig. 2:

Eine Schnittzeichnung der Kombination aus oberem Teil des Stems und Ventilkörper;

Fig. 3:

Den unteren Teil des Stems im Schnitt;

Fig. 4:

Den oberen Teil des Stems mit Dichtmanschette und Fixierring; und

Fig. 5:

Das Federelement.

The invention is explained in more detail by the accompanying figure. It shows:

Fig. 1:

A sectional drawing of the valve according to the invention in a valve disk;

Fig. 2:

A sectional drawing of the combination of the upper part of the stem and valve body;

Fig. 3:

The lower part of the stem in section;

Fig. 4:

The upper part of the stem with sealing collar and fixing ring; and

Fig. 5:

The spring element.

Fig. 1 shows in section an embodiment of a solids valve according to the invention, inserted in a valve plate 1. The solids valve is clamped on the dome of the can via the valve plate 1, the valve plate with its crimped rim 15 engaging over and around the upper edge of the can dome. The valve disk 1 itself has a central recess around which a trough-shaped or trough-shaped central part 11 runs. On the inside, the valve disk 1 is delimited by the rising edge 12, while the tub rises to the Krimprand 15 on the outside.

Inside the valve disk 1 is the valve body 2, in the central round recess of which the valve stem 3 is guided. The valve body 1 is fixed via a rising edge 24 with an outwardly protruding projection 25 on the rising inner edge 12 of the valve disk 1; an outwardly pointing round surface 26 nestles against the underside of the trough 11 of the valve disk 1. The shape of the valve body 1 is stabilized by the circumferential outer edge 26 on the can side.

The valve body 2 has the necessary sealing means to ensure the tightness of the valve with respect to the valve disk 1 around the stem 3. These are possibly sealing lips which are arranged against the rounded area of the valve disk 1 in the transition from the tub 11 to the rising edge 12. On the can side, i.e. on the side of the valve body 2 facing the can interior, there is at least one circumferential sealing lip 23 which runs essentially parallel to the course of the central recess 21 and acts against the foot 31 of the stem. The foot 31 serves as a sealing seat and is a concentric extension of the stem 3 with a slightly curved course. In the rest or closed position of the stem 3 shown here, the sealing lip 23 acts against the foot 31 and prevents the contents of the can from entering the inlet opening 33 of the stem.

In the central recess 21 of the valve body 2, the stem is guided, which has a central channel 34 which serves as an outlet channel for the can contents. On the can side, the stem has at least one lateral opening 33 which serves as an inlet opening for the can contents. In the rest position shown, this inlet opening 33 is closed by the sealing effect of the lip 23 of the valve body 2 against the sealing seat 31 of the stem. When the stem is pressed in, the lip loses its sealing effect and the contents of the can can enter the channel 34 via the inlet opening 33 and exit.

In the embodiment shown, the stem has in its lower part 3b inlet openings 33 which are evenly distributed over the circumference.

According to the invention, the stem 3 of the solids valve is divided into two parts, an upper part 3a and a lower part 3b. The upper part 3a encloses the larger part of the channel 34 and is connected to the valve body 2 via a membrane 22. The valve body 2 and the upper part 3a of the stem 3 are manufactured in one piece using the injection molding process and are preferably made of the same material.

The lower part 3b of the stem cooperates with the sealing lip 23, which acts against the foot 31 of the lower part 3b. There can be several sealing lips.

The upper part 3a comprises the outlet opening of the valve according to the invention and the lower part 3b the inlet openings 33 for the can contents.

The membrane 22, which connects the upper part 3a of the stem to the valve body 2, is arranged concentrically around the stem and has a substantially step-shaped course along the outside of the lower part 3b of the stem. The membrane 22 is sufficiently elastic to absorb the movement of the stem 3 when the pressure cell is triggered. The step-shaped course gives a reserve area, which compensates for the elongation of the membrane when triggered by the displacement of the stem 3. A circumferential recess 27 in the valve body 2, which leaves a gap between the upper end 24 of the valve body 2 and the membrane 22, is also used for this purpose. The membrane 22 attaches to the inside of the valve body 2, follows the course of its inner wall in the area on the can side and then continues in steps to the outer wall of the upper part 3a of the stem.

In addition to its foot, the lower part 3b of the stem has an extension 35 on the socket side, which serves as an abutment for the spring element 40. Only the central part of the spring element 40 is shown. When the stem is actuated, the spring element 40 is moved towards the inside of the can and thus releases the path between the sealing lip 23 and the foot 31 on the lower part 3b of the stem.

In the part 26 projecting towards the can, the valve body has two recesses 29 which engage in the holding arms of the spring element.

The upper part 3a and the lower part 3b of the stem are positively connected to one another. For this purpose, the upper part 3a of the stem has a circumferential bead 28 at its end on the can side, which protrudes precisely into a corresponding widening of the channel 34 in the area of the lower part 3b of the stem.

The upper part 3a of the stem has a cuff which is used to seal off an application aid, such as a foaming gun. Such a sealing collar is preferably made of a thermoplastic elastomer which brings the required sealing properties with it. The upper part 3a of the stem is closed by a fixing ring 43 made of a relatively hard material, which protrudes into the receptacle of a foaming gun and transfers the pressure of the trigger to the stem. Sealing collar 42 and fixing ring 43 are firmly connected to one another. For this purpose, the fixing ring has an annular incision 44 into which a projection 45 of the sealing collar protrudes. The sealing collar 42 is also secured to a recess 46 in the upper part 3a of the stem.

Fig. 2 shows the combination of the upper part 3a of the stem and valve body 2. The upper part of the stem 3a is connected to the valve body 2 via the membrane 22, the membrane 22 taking a stepped profile. The stepped course guarantees the area reserve and at the same time the elasticity of the membrane and thus the flexible integration of the upper part 3a of the stem into the valve body.

The externally protruding projection 25 of the valve body is used to fix it on the inner edge of the valve disk, the circumferential groove 27 providing the necessary elasticity for introducing the valve body 2 into the valve disk 1.

The can-side extension 26 of the valve body 2 causes, on the one hand, a firm seat on the underside of the trough 11 of the valve disk 1 and, on the other hand, provides the recesses 29 for fixing the spring element 40.

The socket-side part of the stem part 3a has a circumferential extension 28 which fits precisely into a corresponding extension of the channel 34 in the region of the lower part 3b of the stem, see Fig. 3 . The inlet openings 33 for the can contents when the valve is actuated and the foot 31, which acts as a sealing seat against the valve body 2, are shown. A socket-side extension 35 of the lower part 3b of the stem 3 interacts with the spring element 40 and at the same time serves to guide and support the valve 3.

Fig. 4 shows the channel 34 of the stem with a sealing collar 42 arranged thereon for the connection of an application aid, for example a pistol. At the upper edge of the upper stem part is the fixing ring 43, which is made of a hard material and absorbs the pressure of the deployment aid when the valve is actuated.

In Fig. 4 the sealing collar 42 and the fixing ring 43 are shown in section, while the upper part 3a of the stem is shown in plan view. It can be seen that the sealing collar 42 and fixing ring 43 are secured to one another in a type of toothing and the sealing collar 42 is secured to a recess of the stem part 3a. The cuff and the fixing ring are connected to one another in a kind of press fit.

Fig. 5 shows the spring clip 40, which has two inwardly notched teeth 47 which are used to fix the spring clip 40 in the recesses 29 of the valve body 2. The teeth 47 cause a very elastic fit and snap into the recesses 29, they serve as holding arms of the spring clip.

The spring clip 40 has a dent 48 in its central lower region, which protrudes towards the inside of the can. The dent 48 lies close to the extension 35 of the lower part 3b of the stem and takes up the pressure which is exerted on the stem by the deployment aid. The spring clip 40 bends under the pressure towards the can and causes the stem to be returned to the closed position after completion of the application process.

Claims (12)

1. Solid matter valve for pressurized cans, in particular for the dispensing/discharging of assembly foams, with a valve disk (1), a valve body (2) arranged in the valve disk (1), a stem (3) mounted in a central cutout (21) of the valve body (2) and having at least one inlet opening (33) for the contents of the pressurized can, said opening being cleared by actuation of the stem (3), with at least one discharge opening, a duct (34) connecting the inlet opening (33) with the discharge opening, at least one sealing element (23) acting between the valve body (2) and the stem (3), as well as a spring element (40), characterized in that the stem (3) is designed so as to form two parts, on upper part (3a) being connected to a lower part (3b) in a form-closed or force-closed manner, a circumferential elastic diaphragm (22) integrally connecting the valve body (2) to the upper part (3a) of the stem (3), and the two parts (3a, 3b) of the stem (3) forming a functional unit which accommodates the duct (34).
2. Solid matter valve according to claim 1, characterized in that the elastic diaphragm (22) has a stepped configuration and extends around the valve-side edge of the lower part (3b) of the stem (3).
3. Solid matter valve according to claim 1 or 2, characterized in that a circumferential depression (27) is arranged between the upper edge of the valve body (2) and the elastic diaphragm (22).
4. Solid matter valve according to any one of the preceding claims, characterized in that the flexible diaphragm (22) has a reserve in surface area to compensate for elongation occurring when the stem (3) is actuated.
5. Solid matter valve according to any one of the preceding claims, characterized in that the central seating area of the lower part (3b) has been provided with an inner circumferential enlargement with a view to accommodating in a form-closed way an outer circumferential bead (28) of the upper part (3a) of the stem (3).
6. Solid matter valve according to any one of the preceding claims, characterized in that the valve body (2) has been provided with a circumferential sealing lip (23) on the can side which interacts with a circumferential projection (31) of the lower part (3b) of the stem.
7. Solid matter valve according to any one of the preceding claims, characterized in that the valve body has an extension (26) on the can side which surrounds the lower part of the stem (3) and serves as a retaining element for the spring element (40).
8. Valve body according to claim 7, characterized in that the spring element (40) is a spring clip having two arms, wherein the arms are secured in recesses (29) on the valve body (2).
9. Solid matter valve according to claim 8, characterized in that the spring clip is bent inwards and has a central bulge into which a central projection (35) of the lower part (3b) of the stem (3) protrudes and which serves for the centering of stem (3).
10. Solid matter valve according to claim 8 or 9, characterized in that the arms of the spring element (40) are provided with can-side notched-out elements engaging in the recess of the valve body.
11. Solid matter valve according to any one of the preceding claims, characterized by a sealing sleeve surrounding the upper part (3a) of the stem (3).
12. Solid matter valve according to claim 11, characterized in that the upper part (3a) of the stem (3) terminates in a fixing ring (43), wherein the fixing ring (43) having a circumferential groove (44) on the can side, into which a circumferential projection (45) of the sealing sleeve engages in a form-closed manner.

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