SPRAY CAN FOR SPRAYING A TWO COMPONENT SYSTEM UNDER PRESSURE

Abstract: The invention relates to a spray can for spraying a two component system under pressure and comprising an outer container (1) for a first component and provided with an aperture, a valve (6) mounted in this opening, an inner container and a stamp (5) having a longitudinal outlet channel (7) which is provided underneath with at least one outlet aperture (8), characterized in that the cover (9) of the inner container (2) is attached underneath said outlet aperture (8) in the valve (6) to the stamp (5) of this valve (6) in such a manner that the outlet channel (7) can be connected to the inside of the outer container (1) by depressing the stamp (5) of the valve (6) without detachment of the inner container (2).

Description: "Spraγ can for spraying a two component system under pressure" The present invention relates to a spray can for spraying a two component system under pressure, such as for example a two component polyurethane foam system, and comprising an outer container for a first component provided with an opening, a valve mounted in this opening and provided for releasing the content of the spray can, which valve comprises to this end a stamp having a longitudinal outlet channel which is provided underneath with at least one outlet aperture and which stamp is slideably mounted in a gasket between a rest position wherein the stamp is pushed outwards by resi¬ lient means so as to seal off said outlet aperture and a depressed position wherein said outlet aperture is open, an inner container for a second component having on one end an opening which is sealed off by a cover by which this inner container is suspended in the outer container, and means for detaching the inner container from the outside of the spray can from its cover so as to enable to mix both components with one another. Such a spray can is disclosed in US patent No 3,318,484. In this known spray can, the cover of the inner container is fixed to the outer container. The cover of the inner container is more particularly integral with the gasket wherein the stamp of the valve is slideably mounted. For detaching the inner container, this stamp is extended underneath by a pen which extends down to the bottom of the inner container. Therefore, not only the outlet apertures in this stamp are opened by depressing the stamp, but the inner container is detached at the same time. A drawback of this known spray can consists in that, after having filled the spray can, the outer container cannot be pressurized by blowing air or an inert gas through the outlet channel and the outlet apertures in the stamp into the spray can. Indeed, these outlet apertures are closed off in the rest position of the stamp. Re-opening these outlet apertures by depress- ing the stamp is not possible since the inner container would then be detached at the same time. If the spray can as described in US-A- 3,318,484 could be pressurized in another way, this known spray can will still offer the drawback that when depressing the stamp in order to detach the inner container, the pressure applied into this spray can would escape through the outlet apertures and the outlet channel before both components are mixed in the spray can. An object of the invention is therefore to provide a spray can which offers a solution for these drawbacks and which can therefore be pressurized easily after the filling operation without requiring hereto further means in addition to the outlet valve. To this end, said cover of the inner container is attached to the stamp of the valve under¬ neath said outlet aperture in this valve in such a manner that the outlet channel can be connected to the inside of the outer container by depressing the stamp of the valve without detachment of the inner container. It will be clear that in this way the valve cannot only be used for releasing the content of the spray can but moreover for pressurizing this spray can after the filling operation. In an effective embodiment of the spray can according to the invention, the means for detaching the inner container comprise a cylinder-plunger mechanism, the cylinder of which is provided onto the bottom of the stamp of the valve, in line with the outlet channel, and the rubber plunger of which is provided for detaching the inner container when it is pushed to its pulled out position, said detachment means comprising further a drift pen for bringing the rubber plunger through the outlet channel into its pulled out position. After having detached the inner container, the rubber plunger will be pushed automatically by the pressure in the spray can back into its initial position so that no pressure can escape through the cylinder. Further particularities and advantages of the invention will become apparent from the following description of a spray can for a two component system according to the invention. This description is only given by way of example and does not limit the invention. The reference numerals relate to the annexed figures. Figures 1, 2 and 3 are longitudinal sections of components belonging to the spray can according to the invention. Figure 4 is a longitudinal section through the components according to figure 3 including moreover a rubber plunger. Figure 5 is a longitudinal section accor¬ ding to figure 4 including moreover an inner container for one of the two components, a safety cap and a drift pen for exerting an axial pressure onto the rubber plunger. Figure 6 is, on a smaller scale, a longitu¬ dinal section of the spray can according to the inven¬ tion, restricted to the outer container with the inner container mounted therein. Figure 7 is, on the same scale, a longitu- dinal section of the spray can as represented in figure 6 with depressed valve and with a schematical representa- tion of the path followed by the gasses supplied under pressure into the spray can. Figure 8 shows the spray can as represented in figure 6 including moreover a safety cap and a drift pen as shown in figure 5 and further a cover. Figure 9 shows the spray can according to figure 8, however without cover. Figure 10 illustrates how the inner container is detached by depressing the drift pen. Figure 11 illustrates the next phase wherein the safety cap and the drift pen are removed. Figure 12 is on a larger scale a longitudi¬ nal section only through the stamp of the valve, shown amongst others in figure 2. Figure 13 is a cross-section according to line XIII-XIII from figure 12. In these figures, the same reference numerals relate to the same or analogous elements. The spray can according to the invention is provided for spraying a two component system, the two components of which are only mixed with one another just before use. It is clear that each of these two compo¬ nents may comprise several different chemical substances. A first component may comprise for example a polyol and an isocyanate from a two component polyurethane system whereas the second component comprises an appropriate catalyst. The spray can shown in the figures compri¬ ses an outer container 1 for the first component and a smaller inner container 2 for the second component. The outer container 1 is provided on its uppermost extremity with an opening wherein a circular collar-piece 3 is fitted in a known and usual way. In this collar-piece 3 there is fixed a valve 6 for releasing the content of the spray can. To this end, this valve 6 is composed of a stamp 5 which is slideably mounted in a resilient gasket 4. The gasket 4 maintains the stamp 5 in the rest position, as represented for example in figure 4, but allows moreover the stamp 5 to be pushed in, as represen¬ ted in figure 7. Through the stamp 5 there extends a longitudinal outlet channel 7 which debouches through four lateral outlet apertures 8 underneath the gasket 4 into the outer container 1. In the rest position of the stamp 5, these outlet apertures 8 are sealed off due to the fact that the stamp 5 is pushed against the bottom of the gasket 4. In order to open the outlet apertures 8, the stamp 5 of the valve 6 has to be depressed. Around the outlet apertures 8, a circular recess 18 is provided into the resilient gasket 4. Below the outlet apertures 8, the stamp 5 is provided with a cover 9 to which the inner container 2 is suspended in the outer container 1. The inner container 2 is more particularly pushed partially over the cover 9. A resilient O-ring 10, which extends partially in an outer circular groove 19 of the cover 9 and partially into an opposite internal groove 20 in the inner container 2, ensures that the inner container 2 remains fixed to its cover 9. At its lowermost extremity, the stamp 5 is further provided with a cylinder-plunger mechanism comprising a cylinder 11 and a rubber plunger 12 which is provided for detaching the inner container 2 when it is pushed from its initial position, as shown in figure 9, to its pulled out position, as shown in figure 10. To this end, there is applied between the rubber plunger 12, composed of a resilient disk, and the bottom of the inner container 2 a piston pen 13 which, as represented in the figures, may be fixed to the rubber plunger 12 but which may also be free from this rubber plunger 12. Prefera- bly the uppermost extremity 21 of the piston pen 13 fits accurately into the cylinder 11, more particularly with rings 22, in order to maintain in this way the piston pen 13 upwards when the inner container 2 is disengaged (see figure 11) . In a variant embodiment which is not shown in the figures, the piston pen 13 is free from the piston 12 and can then for example be fixed at the top in the inner container 2 through transverse connections against the wall of this container 2. In the spray can as represented in the figures, the cylinder 11 is in line with the outlet channel 7 of the valve 6 so that the rubber plunger 12 can be pushed by means of a drift pen 14 through the outlet channel 7 into the pulled out position. The outlet channel 7 is preferably separated from the cylinder 11 by a thin wall 15 so that no pressure can escape during the storage of the spray can. Before use, this thin wall 15 has to be pierced by means of the drift pen 14. Upon piercing this thin wall 15, it is important to prevent the stamp 5 from being depressed since the pressure in the spray can would otherwise escape through the outlet apertures 8. To this end, the spray can according to the invention comprises a safety cap 16 which, as represented in figures 9 and 10, is screwed on the outside onto the stamp 5 of the valve 6. An important advantage of the spray can according to the invention is that it is simple to pressurize after having filled and assembled both containers (see figure 6) , more particularly by means of the valve 6 for releasing the content of the spray can. As a matter of fact, this valve 6 can be opened simply as represented in figure 7 by pushing onto the stamp 5 without causing the inner container 2 to be detached hereby. After having pressurized the spray can, the safety cap 16 is screwed onto the valve 6 and the drift pen 14 is applied into the valve 6. Finally, a cover 17 is further screwed onto the spray can. In order to make the spray can ready for use, the cover 17 has to be removed and the drift pen 14 has to be knocked in by means of a heavy object. After having removed this drift pen 14 and the safety cap 16, a so-called "adapter", which is known per se, can be screwed onto the valve 6. The structure of this adapter does not belong to the essence of the invention and is therefore not described further into detail. The two component composition can then be sprayed in the usual way by means of the adapter.

Claims: CLAIMS 1. Spray can for spraying a two component system under pressure and comprising an outer container (1) for a first component provided with an opening, a valve (6) mounted in this opening and provided for releasing the content of the spray can, which valve (6) comprises to this end a stamp (5) having a longitudinal outlet channel (7) which is provided underneath with at least one outlet aperture (8) and which stamp (5) is slideably mounted in a gasket (4) between a rest position wherein the stamp (5) is pushed outwards by resilient means (4) so as to seal off said outlet aperture (8) and a depressed position wherein said outlet aperture (8) is open, an inner container (2) for a second component having on one end an opening which is sealed off by a cover (9) by which this inner container (2) is suspended in the outer container (1) , and means for detaching the inner container (2) from the outside of the spray can from its cover (9) so as to enable to mix both components with one another, characterized in that said cover (9) of the inner container (2) is attached to the stamp (5) of the valve (6) underneath said outlet aperture (8) in this valve (6) in such a manner that the outlet channel (7) can be connected to the inside of the outer container (1) by depressing the stamp (5) of the valve (6) without detachment of the inner container (2) . 2. Spray can according to claim 1, characterized in that the means for detaching the inner container (2) comprise a cylinder-plunger mechanism (11,12) , the cylinder (11) of which is provided onto the bottom of the stamp (5) of the valve (6) , in line with the outlet channel (7) , and the rubber plunger (12) of which is provided for detaching the inner container (2) when it is pushed to its pulled out position, said detachment means comprising further a drift pen (14) for bringing the rubber plunger (12) through the outlet channel (7) into its pulled out position. 3. Spray can according to claim 2, characterized in that said cylinder (11) and the outlet channel (7) are mutually separated by a thin wall (15) , which thin wall (15) can be pierced by means of the drift pen (14) . 4. Spray can according to claim 2 or 3, characterized in that said rubber plunger (12) is composed of a resilient disk (12) , and a piston pen (13) being applied between this disk (12) and the inner container (2) , in particular between the disk and the bottom of the inner container (2) . 5. Spray can according to claim 4, characterized in that the piston pen (13) is free from said resilient disk (12) . 6. Spray can according to claim 5, characterized in that the uppermost extremity (21) of the piston pen (13) fits slideably in said cylinder (11) . 7. Spray can according to any one of the claims 1 to 6, characterized in that the inner container (2) and its cover (9) are slid into one another and a resilient O-ring (10) being provided between both of them,- which ring extends partially into a groove in the inner container (2) and partially into an opposite groove (19) in the cover (9) of this inner container (2) . 8. Spray can according to any one of the claims 1 to 7, characterized in that said stamp (5) is threaded at its top so as to enable a safety cap (16) to be screwed thereon in order to block the stamp (5) in the rest position, in particular when use is made of said drift pen (14) .

Inventors: BAETEN TON, BAETEN, TON
Applicants: SOUDAL
Application year: 1992
Main classification: B65D83
IPC codes: B05B11, B65D83