Two-component pressure container for producing foam

A two-component pressure container is provided. The pressure container comprises a valve, an outer container for a first component and a foaming agent as well as an inner container sealed against the outer container for the second component and eventually another foaming agent, in which the outer container is provided with a tube extending towards the bottom of the box. The inner container is affixed in a detachable manner and hermetically sealed against the outer container by sealing elements, and in which, by actuating the valve from the outside, the inner container can be opened into the outer container. Such a two-component pressure container is particularly suitable to produce two components foams, e.g., polyurethane foams.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates to a two-component pressure container box with a 
valve, an outer container for a first component and a foaming agent as 
well as an inner container sealed against the outer container for the 
second component and eventually another foaming agent, in which the outer 
container is provided with a tube extending towards the bottom of the box, 
and the inner container is affixed in a detachable manner and hermetically 
sealed against the outer container by means of sealing elements, and in 
which, by actuating the valve from the outside, the inner container can be 
opened into the outer container. Such a two-component pressure container 
is particularly suitable to produce two-components foams, e.g., 
polyurethane foams. 
2. Description of the Prior Art 
In particular, to produce two-component plastic foams, many techniques were 
developed to house separated from each other the reactive components that 
are necessary for the foam formation. For this, into an outer pressure 
container containing the prepolymer is usually inserted a second, inner 
pressure container with the second component, the content of which is 
emptied into the prepolymer by releasing it from the outside, thus mixing 
it with the prepolymer. The therein originated reactive mixture is then 
ejected by a foaming agent in the pressure container under foam formation. 
In known two-component pressure containers the inner container for the 
second component is located, e.g., in the area immediately above the box 
bottom. The release mechanism, by means of which is achieved the combining 
of the two components, is affixed at the bottom of the box and is actuated 
either by pressing or by twisting. By way of example, reference is made in 
this respect to the German registered utility patent 82 27 228 as well as 
to DE-A-30 22 389 and DE-A-33 22 811. 
The disadvantage of these known solutions with a release mechanism in the 
bottom area is that, apart from the costly valve construction in the dome 
area of the pressure container, a second, costly molded area is necessary 
at the bottom of the container. On the one hand, this increases the 
manufacturing requirements and thus the manufacturing costs and, on the 
other hand, it creates a second area at the pressure container that is 
susceptible to influences from the outside, which must be protected 
against forced influences from outside by means of suitable measures, such 
as, e.g., the placing of gaskets, protecting caps or safety devices. 
Furthermore, the valve for the filling of the pressure container with a 
foaming agent cannot be easily arranged--as it is customary in some 
instances--in the middle of the chamber container. 
It is further known, to arrange the inner container of a two-component 
pressure container directly below the valve assembly in the upper area of 
the pressure container. Pursuant to U.S. Pat. No. 3,635,261, an inner 
container arranged in such a manner below the valve assembly is placed 
under such a high pressure by means of a propellant-filled cartridge, 
affixed from the outside, that it bursts, that the content of the inner 
container discharges into the outer container, thus obtaining the desired 
mixing of the two components. Subsequently, the mixture is released in the 
usual manner by means of the valve. 
Pursuant to U.S. Pat. No. 3,318,484 an inner container arranged in such a 
manner below the valve assembly is opened and discharges into the outer 
container because, through a downward movement of the valve, a rod 
arranged inside the inner container extending to its bottom acts upon the 
bottom in such manner that it loosens the gasket between the inner 
container and the mounting in the dome of the pressure container. A 
disadvantage in this connection is, however, that the content of the inner 
container can also be activated by an unintentional pressure or impact 
effect, resulting in a premature mixing of the components in the 
container. Furthermore, an actuation of the valve prior to the mixing of 
the two components cannot be excluded, which would result in a premature 
discharge of the inner container, thus rendering unusable the entire 
content of the pressure container because the amounts of the two 
components are not formulated for each other. 
All in all, the hitherto known pressure containers with an inner container 
arranged in the upper area have proven to be somewhat unreliable, so that 
such pressure containers did not find acceptance on the market. On the 
other hand, however, the arrangement of the inner container on the inside 
of the valve unit is desirable in order to concentrate at one place the 
technically important elements of such a pressure container, which has 
manufacturing engineering advantages, and to keep low the number of the 
movable elements of such a pressure container which, in turn, has 
application and safety engineering advantages. 
From EP-A-0 528 190 is known a two-component pressure container with an 
outer container for a first component and foaming agent and an inner 
container sealed against the outer container for the second component and, 
eventually, another foaming agent, in which by means of the valve the 
inner container can be opened to the outer container, by rotating the 
valve tube towards the valve seat. This can be obtained by an arrangement 
in which the outer container is provided at the valve disk with a tube 
extending to the bottom of the box, in which in the tube is placed a gear 
mechanism that is connected to the valve tube by an extension piece 
through the valve body, which under a rotary movement of the valve pipe 
actuates upon a journal in direction to the bottom of the pipe, and being 
the inner container detachably mounted at the bottom of the tube and 
hermetically sealed against the inside of the tube by means of a sealing 
element. A rotary movement of the valve tube causes a downward movement of 
the journal that, acting upon the inner container, irreversibly disengages 
it from the tube. 
These two-component pressure containers have proven themselves in practical 
operation but, because of the journal's free movability in the tube, they 
require special care when filling them with propellant, when this filling 
shall be effected through the valve assembly. It turned out, however, that 
because of the suddenly occurring pressure surge during filling, the 
journal can be driven toward the inner container, which can lead to its 
premature opening into the outer container. Furthermore, the sudden 
pressure surge can lead to that the tube arranged at the valve disk is 
disengaged from its seat, dropping together with the inner container into 
the outer container. Although in such a case the inner container does not 
open into the outer container, the pressure container is ruined for the 
intended use. 
Thus, the purpose of the invention is making available a two-component 
pressure container in which a second container is arranged below the valve 
unit, that is of easy manufacture, of safe storage and protected against 
an unintentional disengaging, and that makes possible a reliable 
disengaging with a subsequent complete mixing of both components as well 
as an easy filling of both the inner and the outer containers. In 
particular, the inner container shall be protected against an undesirable 
displacement when filling the pressure container with propellant through 
the valve. 
This task is solved by means of a pressure container of the initially 
described type, in which the valve tube presents a contact element at its 
section extending through the valve body into the outer container; this 
contact element locks into a complimentarily formed recess in a screw 
assembly that meshes with an outside thread into a female thread of the 
tube arranged above the inner container, so that a rotary motion of the 
valve tube is imparted to the screw assembly by means of the contact 
element, separating the inner container through the thus resulting 
downward movement of the screw assembly. By means of the solution 
according to the invention, a rotary motion imparted by means of the valve 
stem to the valve and the therewith connected contact element is 
transmitted to the screw assembly and continues as forward thrust upon the 
inner container arranged at the end of the tube. As a result thereof, the 
inner container is separated from the end of the tube, so that the 
content, eventually under the pressure of a propellant gas, discharges 
into the content of the outer container, thus mixing with by an eventual 
shaking. A prerequisite for the separation process is, however, the rotary 
motion at the valve tube; thanks to the toothing of the gears a mere 
pressure exertion is not converted into a forward thrust. 
Conventional tin containers or aluminum-drawn boxes can be considered as 
pressure containers. 
By way of example, the tube is affixed to a concentric projection of the 
valve dish extending into the inside container. In particular, in the case 
of the tube it deals with a plastic tube that is tightly slipped over this 
concentric projection of the valve dish, thus extending vertically 
downward from the valve into the pressure container. At its valve-facing 
end it presents discharge openings in its wall, that render possible the 
passing through of the foam mass when emptying the pressure container or 
of the filling compound when filling the pressure container, respectively. 
Of particular preference is an embodiment in which the tube presents at its 
valve-facing end an inside continuous groove into which engages a 
concentric projection of either the valve dish or, in particular, of the 
valve body. Instead of an inside continuous groove there can also be 
provided a continuous projection, extending inward in a step-like manner, 
or a protrusion of such type as to engage behind a continuous projection 
of the valve body or of the valve dish, or a combination of groove and 
projection. 
As mentioned above, the rotary motion of the valve toward the valve seat to 
open the inner container is converted by a screw assembly into a downward 
directed movement. This is obtained by a combined action of the contact 
element at the bottom of the valve tube with the recess in the screw 
assembly. The contact element at the valve tube consists advantageously of 
a many-sided end piece, for example, a hexagon. However, any other 
embodiments of the contact element can also be used, on condition that 
they are provided with the toothing required for the rotary motion. 
The contact element is preferably lodged or guided sliding vertically in 
the recess, so that by a pressing down on the valve tube it is possible to 
fill the container without having to separate the tube assembly with the 
inner container. For this purpose, a clearance is necessary between the 
bottom end of the contact element and the bottom of the recess, into which 
the contact element can slide by pressing down on the valve tube. 
Furthermore, the contact element and the recess are formed sufficiently 
long, in order to ensure a combined action up to the complete separation 
of the inner container with the downward-screwed screw assembly. 
The valve tube, the contact element and the screw assembly, as well as the 
tube and the inner container, are made out of the customary suitable 
materials such as, e.g., a plastic, for instance polyethylene or 
polypropylene. 
As stated above, the inner container is located at the side of the tube not 
facing the valve. Preferably, the upper, open end of the inner container 
is frictionally inserted into the tube, for which a gasket is provided 
between the outer wall of the inner container and the inside wall of the 
tube. In connection with another gasket, that is preferably formed between 
the screw assembly and the tube, there is obtained an effective separation 
of the content of the inner container from the outer container. This 
separation ceases to exist through the above described downward movement 
of the screw assembly by a rotary motion of the valve tube, inasmuch as 
the screw assembly pushes against the inner container pressing it out of 
its seating at the bottom of the tube. Thus, the content of the inner 
container is released and--with an adequate overpressure existing in the 
inner container compared to the outer container--it is also immediately 
ejected. The two-component pressure container is ready after the release 
and an eventually further shaking. 
The gaskets between the inner container and the tube or between the screw 
assembly and the tube, respectively, are preferably formed as O-rings, 
that are seated in correspondingly shaped annular grooves. 
The contact element is preferably arranged immediately below the disc that 
supports the valve tube against the bottom side of the valve body. It is 
advantageous for this disc to mesh into a round extension of the recess of 
the screw assembly, without however extending to its bottom end, so that 
by pressing down on the valve tube it can be pushed in farther. An annular 
gasket in a groove in the dish prevents the infiltration into the intake 
of the filling compound. 
It is advantageous that the pressure container according to the invention 
is provided with a handling mechanism at the valve tube for a boosting of 
the rotary motion. This handling mechanism is screwed on to the valve tube 
whereby attention must be paid that the pitches of the screw thread at the 
valve tube and at the screw assembly or at the tube, respectively, run in 
such a manner as to avoid a loosening of the handling mechanism during the 
release. By way of example, such a handling mechanism consists of an 
extension of the valve tube that can be offset in the upper area, and 
presenting vertically projecting cross struts, that serve for the boosting 
of the rotary motion and, as a whole, result in a cruciform shape of the 
extension and the struts. 
The pressure container according to the invention is also provided with a 
valve that can be used in both directions, which facilitates the filling 
of the pressure container. Thus, it is possible to fill at first the outer 
container with the prepolymer, e.g., a two-component foam, then to put in 
place the valve case with the connected and filled inner container, and 
finally to fill the already closed container through the valve tube and 
the corresponding openings in the tube with the propellant gas required 
for the discharge of the filling. In such a manner, the entire content of 
the outer container can be loaded.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The pressure container shown in the drawings consists of a body 1 that is 
closed at one extremity with a dome 2. The dome 2 shows a tanged rim 3 
that fastens the dome 2 to the referenced extremity of the body 1, 
concomitantly bringing about a tight connection of the components. The 
pressure container dome is made out of a round blank, that is to say, a 
round plate, a shaped part cut out of tin plate, which by deformation was 
given the dome-shaped form shown in the drawing. As shown in FIG. 1, the 
inside rim of the blank is tanged and holds the valve 5. On its part, the 
rim 7 of the valve disk 6 is tanged around rim 4 of the blank and it is 
thus sealed against it. In the center of the valve disk is a rubber plug 8 
that, on its part, is held by a flange-like widening 9 to the underside 10 
of the valve disk 6, and through which passes a hollow valve tube 12. This 
valve tube has an outer flange 13 that rests on the outer rim 14 of the 
plug. A disk 15 closes the valve tube 12 at its lower extremity. By 
tilting of or pressing on the valve, one or more openings 16 become 
accessible for the content of the container and serve for conveying the 
content of the container. The bottom of the pressure container is formed 
by a curved plate 17 that is tanged with its rim 18 around the 
corresponding extremity of the body 1. 
The disk 6 of the valve assembly 5 is downward depressed in its central 
area and forms an edge 20 that runs concentrically around the rubber plug 
8 and protrudes into the inside of the container; it can also radially 
project into the inside of the container. The projection or edge 20 serves 
as seat for a thereto connected tube 21, that is provided with an inner 
container 23 at its lower extremity. The inner container can be 
manufactured in one piece or--to facilitate the filling--it can be 
provided with a separate bottom. 
FIG. 2 shows a cross-sectional view through the top end of a pressure 
container according to the invention as shown in FIG. 1. Underneath the 
valve assembly is the tube 21, that is slipped onto the edge 20 of the 
disk 6 and clamped in place to it. The seat of the tube 21 at the 
projection 20 is always so firm that it is impossible for the release 
mechanism to separate the inner container. In accordance with a special 
embodiment this can also be achieved, in that the edge 20 is widened to 
form a projection that is gripped by a projection at the upper extremity 
of the tube 21. Additionally or alternatively, the tube 21 can be secured 
to a projection or flange 19 of the valve body 6 by means of a groove 
provided on its inside. 
Underneath the valve in the upper half of the tube 21 are provided openings 
24, through which the outer container of the pressure container can be 
filled, and through which can be discharged the foam agents. 
A disk 15, that becomes a contact element 26, is arranged underneath the 
valve body 9 as a direct extension of the valve tube 12 and is tightly 
connected to it. The contact element is of polygonal shape, in the present 
case a hexagon 26. 
The contact element 26 acts in conjunction with a complementary thereto 
formed screw assembly 22, both of which constitute the separation 
mechanism for the inner container 23. For this purpose, the contact 
element 26 underneath the disk 15 is of hexagonal shape and engages into 
an also hexagonally shaped recess 30 of the screw assembly 22. Through the 
contact element 26, a rotary motion of the valve tube 12 is thus imparted 
to the screw assembly 22 which, in its mounting, is screwed downward in 
direction of the inner container 23. 
In order to seal the hexagonally shaped recess 30 against infiltrating 
filling material, in the upper region is provided a circular widening 28 
(see FIG. 3) into which can engage the disk 15 of the valve tube, and 
render effective a sealing element 33, preferably an O-ring, arranged 
along its periphery. Concomitantly, the circular widening 28 of the 
hexagonal recess 30 of the screw assembly 22, that extends into the screw 
assembly 22 by more than the thickness of the disk 15, allows a vertical 
play of the valve tube 12. A prerequisite for this is, however, that the 
contact element 26 does not fill the recess 30 as far as its bottom but 
that it also leaves a clearance. In this manner, the container can be 
filled through the valve tube by pressing down on the valve tube 12. 
Furthermore, in the outer wall of the screw assembly 22 is provided a 
recess 27, that leaves a clearance in the area of this recess 27 between 
the wall of the tube 21 and the inserted screw assembly 22. Inside this 
clearance are provided the openings 24, that allow the passage of the 
filling material into the inside of the container when filling is effected 
through the valve tube 12, and the discharge of the foam from the inside 
of the container into the valve pipe 12. 
The screw assembly 22 is screwed into a box thread 32 of the tube 21 by 
means of an external thread 31 that extends beyond the thickness of the 
screw assembly, and is held in this position by this thread. Through a 
rotary motion of the valve tube 12 and the transmission of this rotary 
motion by the contact element 26, this screw connection can be loosened 
and the screw assembly 22 can be screwed downward out of its mounting. 
Directly underneath the screw assembly 22, the inner container 23 is 
frictionally slipped within the tube 21. The seat of the inner container 
23 can be improved by a suitable shaping of the container rim and/or of 
the tube 21. The sealing of the inner container 23 against the outer 
container 21 is obtained by annular gasket-sealing washers 36 above the 
screw threads 31/32 between the inside wall of the tube 23 and the outside 
wall of the inner container 23, as well as between the screw assembly 22 
and the tube 21. 
FIG. 3 shows the individual components of the separating mechanism from 
FIG. 2. Therein, the contact element 26 is connected directly underneath 
the valve plate 15 to the valve tube 12 and firmly connected to it. The 
valve plate 15 is provided with a circular groove into which is inserted a 
gasket 33. Underneath the plate 15 is arranged the contact element 26, 
herein shown in its longitudinal cross-section, shaped as an hexagonal 
that is hollow on its inside. It must be understood, that the hollow 
section of the contact element 26 does not extend into the valve tube. 
The screw assembly 22 is illustrated underneath the contact element 26 and 
presents the centered recess 30, also of hexagonal shape and as complement 
to the contact element 26. Above the recess 30 is provided a circular 
widening 28, into which the valve plate 15 with its continuous annular 
gasket is partially inserted in such a manner that a clearance is provided 
for a downward movement to the end of the widening 28. The length of the 
contact element 26 is coordinated with the depth of the recess 30 in such 
a manner that there is provided a vertical clearance that allows a 
pressing-in of the valve tube for the filling of the pressure pump. 
The screw assembly 22 presents in its outer region an upper recess 27, that 
leaves free a continuous groove in the upper region of the screw assembly 
22 inserted into the tube assembly 21. In the area of this groove are the 
openings 24 in the tube 21, through which can pass the propellants or the 
foaming agents, respectively. 
In the lower region of the outer wall of the screw assembly 22 is located 
the screw thread 31, that meshes into a correspondingly shaped inside 
thread of the tube 21. The placing of the outside thread 31, projecting 
opposite to the wall, in connection with the inside thread 32, recoiling 
into the wall of the tube 21, allows the vertical displacement of the 
assembly 22 inside the tube 21. As sealant against the upper valve area, 
above the outside thread is provided a continuous groove for a gasket, 
preferably an O-ring, herein designated as 34. A recess 29 in the lower 
area of the outer wall of the assembly 22 does also constitute a 
continuous groove when the element 22 is screwed in, into which can mesh 
the rim of the inserted inner container 23 (see FIG. 2). 
In respect to the valve tube 12, mention must be made of thread 38, by 
means of which can be screwed on a handling mechanism for the rotating and 
the actuating of the release mechanism. 
FIG. 4 shows the longitudinal cross-section of a tube 21. In the upper 
region of the assembly are located the openings 24 for the filling 
compound--herein are shown only two but more than two can be provided 
around the periphery of the tube 21. Above the openings is provided a 
recess or groove 19, into which can mesh a correspondingly shaped 
projection 9 of the valve body 9. Through this provided a flexible 
connection between the valve body 9 and the tube 21, which is suitable to 
partly absorb any movement of the valve body. Furthermore, this connection 
supplements the support obtained by the tube 21 by mounting it over the 
inside rim 20 of the valve disk 6. In order to facilitate the mounting, 
the tube wall tapers at its upper extremity from the inside toward the 
outside, forming thus a bead 42 above the groove 19. 
On the inside of the tube 21 is arranged the continuous inside thread 32, 
that acts in conjunction with the outside thread 31 of the screw assembly 
22. Beneath the inside thread 32, the inside wall of the tube 21 forms a 
recess 37 against which rests the inner container 23 with a corresponding 
recess in the upper outer wall of the container and a continuous groove in 
the annular gasket 36. 
FIG. 5 shows a longitudinal cross-section through the bottom of the tube 21 
and the top of the inner container 23, for an illustration of one type of 
the fastening. In tube 21 is shown the thread 32 of the journal into which 
the screw assembly 22 is screwed in from below. In the bottom region of 
the tube is provided the recess 37, designed as two concentrically steps 
39 and 40 inside the tube 21. 
In addition thereto, the recess 35, running along the outer wall of the 
inner container 23, directly underneath the rim presents a groove with in 
O-ring 36, as well as projection 41 at a slight distance from this groove. 
With an adequate seating, the gasket 36 and the projection 41 act in 
conjunction with the step 39 of the tube 21, while the part of the wall of 
container 23, without the recess, slides into the area of the step 40 of 
the tube 21.