Method and apparatus for enveloping with a flexible package

Abstract: A flexible package (7) for rescue equipment, specially adapted to be mounted on the exterior of a craft of the submarine type, the package being compressible around its contents so that it will take up a minimum volume. The method of compressing the package is performed in a pressure vessel (1) containing fluid (5) into which the package is immersed. The package has a connection through a non-return valve (9) to a tube (8) communicating with the surrounding atmosphere. Pressurizing of the package takes place through a three-­ way-valve (4), when the air contained in the package is expelled through the tube (8). On evacuation of the pressure vessel (1) the non-return valve (9) will close and the package (7) and its contents will remain in a compressed state.

Description: This invention relates to improvements in or relating to flexible packaging. In particular, the present invention relates to a method as disclosed in Claim 1 and to a combination of package and apparatus for reducing to a minimum the volume of a flexible package and the contents thereof. This is done in a pressure vessel into which the package and its contents are inserted through a sealable opening and which is provided with a pressure conduit for regulation of its internal pressure. The present invention also relates to a package obtained in accordance with the aforesaid method as in Claim 6. In the case of, for example, craft of the submarine type, installation of easily-accessible rescue equipment (such as lifeboats and the like) presents a problem. The equipment has commonly been installed inside and to near the exits of the craft. Since the area of the exits tends to be limited, it is difficult to bring the equipment out to the exterior of the craft, especially in emergency situations. It has also been suggested to dispose the equipment outboard. For this, however, separate pressure-tanks have been required, in which the rescue equipment is kept and which need to be independent of the pressures existing at different water depths to which the craft is capable of descending. From the point of view of design and operation, such separate pressure-tanks obviously present less satisfactory solutions. By means of the present invention, the above-described problems will be eliminated. The package containing the rescue equipment is intended to be disposed inboard or outboard, for example in close vicinity of the fin of a submarine. Owing to the package being flexible and having been given a minimum volume in accordance with the invention so that it conforms to the shape of the rescue equipment, said equipment is capable of being kept in position independent of the depth reached by the craft. In this way, there is no risk of damage to the rescue equipment. Thus, the rescue equipment is enclosed in a package, the volume of which has been reduced to a minimum in that substantially all air contained in the package has been expelled from the same, by means of the method according to Claim 1 and an apparatus according to Claim 3 of the present invention. Methods and apparatuses for packaging articles under pressure are known. Thus, for example, US-A-2 780 043 describes a method and an apparatus for packaging foodstuffs in evacuated packages by means of a pressure chamber. The pressure chamber is pressurized at the same time as the interior of the package contained therein is connected to a vacuum pump for evacuation of substantially all air. According to a preferred embodiment of the present invention, compression of the package is carried out below the surface of a liquid contained in the pressure vessel. In this way, a good all-round effect on the package is achieved. A preferred embodiment of the present invention will be illustrated, merely by way of example, in the following description and with reference to the accompanying drawing. The drawing shows a schematic view of a pressure vessel 1 provided with a manhole cover 2 and a conduit 3 for regulation of the pressure in the pressure vessel 1. To the conduit 3 there is connected a three-way-valve 4. The pressure vessel 1 is partially filled with a liquid 5, for example water. The drawing also shows a package 7 immersed below the surface 6 of the liquid 5, the interior space of the package communicating with the atmosphere surrounding the pressure vessel by means of a tube or pipe 8 which is connected to a non-return valve 9 on the package 7. When compression of the volume of a flexible package 7 and the rescue equipment (not shown) enclosed therein is to be carried out, the three-way-valve 4 is operated so that the interior of the pressure vessel 1 will be connected to the surrounding atmosphere, as indicated by the arrow P2. The manhole cover 2 is opened and the package 7 and its contents is inserted into the pressure vessel 1 through the manhole. The pipe coupling with non-return valve 9 contained within the package 7 is connected to the tube 8. The package 7 is then immersed below the liquid surface 6 and the manhole cover 3 is closed. The three-way-valve 4 is now operated to pressurize the pressure vessel 1 by means of a suitable pressure medium in the direction indicated by arrow P1. The pressure medium may be, for example, air or nitrogen. Pressurizing is preferably carried out to a level which is higher than the pressure to be expected during later normal storage of the package on board a craft. On pressurizing of the pressure vessel 1, the liquid 5 will exert an all-round pressure on the walls of the flexible package 7. The air enclosed in the package 7 will then be expelled to the atmosphere surrounding the pressure vessel 1, through the non-return valve 9 and the tube 8. After a suitable pressure has been established in the pressure vessel 1 (or after a predetermined time) the flexible package 7 will assume a minimum volume substantially conforming to the shape of the rescue equipment (not shown) enclosed therein. When said amount of time has passed (or when it has been established that air is no longer escaping from the tube 8) the three-way-valve 4 is again operated so as to reconnect the interior of the pressure vessel 1 to the surrounding atmosphere (arrow P2). In consequence of the fall of pressure in the pressure vessel 1, the non-return valve 9 will close and the compression of the package 7 will remain. When the pressure in the pressure vessel 1 has fallen to atmospheric pressure, the manhole cover 2 is opened and the package is disconnected from the tube 8 and removed, still in its compressed state. Another package may now be inserted in the pressure vessel 1 and the process repeated. While a preferred embodiment has been described above, it will be understood that the invention is not limited thereto. Various modifications may be made without departing from the scope of the invention. For example, the tube 8 may be provided with an outer valve making possible regulation of the gas connection between the package 7 and the atmosphere. Further, the liquid 5 may be a liquid other than water. Although the present invention has been described with reference to its use in marine craft, other applications are possible, such as packaging of rescue equipment for use in aeroplanes where minimum volumes constitute an important advantage. Thus, the invention includes various alternative embodiments and is limited only by the following claims.

Claims: A method of reducing to a minimum the volume of a flexible package (7) and rescue equipment contained therein, said method being performed in a pressure vessel (1) into which the package (7) containing the rescue equipment is inserted, characterized by fitting a connection (8) to a non-return valve (9) of the package (7), placing the package (7) in the pressure vessel (1) with the connection (8) providing communication between the interior of the package and the exterior of the pressure vessel (1), raising the pressure in the pressure vessel (1) to a predetermined value to cause the air enclosed in the flexible package (7) to be expelled through the connection (8) provided with said non-return valve (9) to atmosphere surrounding the pressure vessel (1) and to achieve the minimum volume of the package (7) which conforms to the shape of the rescue equipment, restoring the pressure in the vessel to atmospheric pressure and removing the package (7) and the equipment from the vessel (1), the said minimum volume and shape being maintained by the closure of the non-return valve (9) after the air has been expelled from the package (7). A method according to Claim 1, characterized in that , prior to pressurizing of the pressure vessel (1), the package (7) containing the rescue equipment is immersed below the surface (6) of a liquid (5) contained in the pressure vessel (1). A combination of a package containing rescue equipment and an apparatus for reducing the volume of the package and equipment contained therein to a minimum, characterized in that the apparatus comprises a connection (8), a pressure vessel (1) and a pressure conduit (3), the connection (8) being for fitment to a non-return valve (9) of the package, the pressure vessel (1) having a sealable opening (2) for insertion of the package (7) and the pressure conduit (3) being for regulating the pressure in the pressure vessel (1), the connection (8) of the apparatus and the non-return valve (9) of the package (7) connecting the package (7) to the atmosphere surrounding the pressure vessel (1) thereby allowing the air enclosed in the package (7) to be expelled to the atmosphere when the pressure in the vessel (1) is raised, the non-return valve (9) of the package (7) closing after the air has been expelled from the package (7). A combination according to Claim 3 characterized in that the non-return valve (9) is disposed within or on the package. A combination according to Claim 3 or 4, characterized by a liquid (5) contained in the pressure vessel (1) and below the surface (6) of which the package (7) is immersed on pressurizing of the pressure vessel (1). A package of flexible material enclosing rescue equipment and adapted to be mounted for example on the exterior of a craft of the submarine type, characterized in that a non-return valve (9) is disposed within or on said package (7) and air has been expelled from the package (7).

Inventors: GRANFELT CLAES, GRANFELT, CLAES
Applicants: BTR PLC
Application year: 1990
Main classification: B63C9
IPC codes: B65B31, B63C9