EP0127522A1 - Rain and spray water tight pressure equalising device, particularly for transport containers - Google Patents

Abstract

This device comprises a chamber (9) having an external wall (10), and an internal wall (12) which separates it from the container, said chamber (9) communicating with the outside via at least one orifice (16, 16a, 16b , 16c) of said outer wall (10) and with the interior of the container by a tube (13) extending through said inner wall (12) and projecting into said chamber (9), the shape of said inner wall (12) and the position of said orifice (16, 16a, 16b, 16c) being such that in any position of the container, the orifice or a part of it is located at a level below that of the internal end (15) of said tube (13) so that a liquid in the chamber can not enter the container.

Description

The present invention relates generally to the containers used for the transport of fragile materials such as electronic, electromechanical, optical or other materials used for example in the aeronautical, space, medical fields, etc. and it relates more particularly to a device for balancing the internal pressure of these containers with atmospheric pressure.

These containers must provide effective protection against handling risks (shocks, falls) and must be waterproof against rainwater and runoff. The latter imperative involves a construction with an almost perfect airtightness.

This airtightness causes well-known drawbacks which are due to variations in the pressures inside and outside the container. These pressure variations can have two main causes, one of which is the temperature difference between the inside and the outside of the container subjected to variations in ambient temperature and the other of which is due, for example, to variations in altitudes during air transport by plane or by helicopter, pressurized or not. In addition, these two causes can add up in certain cases.

The pressure difference can reach values such that the deformations of the container may be harmful to the materials it contains.

To overcome these drawbacks, the containers have been made of a sufficiently resistant material, which leads to an expensive weight increase in the case of air transport in particular.

There has been described in US Patent No. 2,113,454 a self-closing vent valve device when the container is in a position other than its normal position. This device does not ensure watertightness when the container is in an upright position.

There has been described in US Patent No. 2,939,603 a pressure balancing device consisting of a relief valve actuated by means of a screw. This device requires tightening or loosening the screw; when the screw is tightened it prevents pressure balancing and when it is loose the container is no longer waterproof against rain and runoff.

French patent no. 2,369,175 and its addition no. 2,436,718 describe an arrangement of vacuum chambers in a container, intended for the ventilation of the side walls. The arrangement of these chambers which include baffles does not prevent the penetration of rainwater and / or runoff into the various positions of the container and is in addition complicated and consequently expensive to construct.

It follows from the above that the devices of the prior art do not make it possible to solve both the problems of water tightness and of pressure balancing in a satisfactory manner, although there are so-called equipression valves which are often complex materials requiring periodic maintenance to guarantee their proper functioning.

The invention aims to remedy these drawbacks by providing a pressure balancing device for a container, in particular for transporting fragile materials, which permanently balances the internal pressure of the container with atmospheric pressure while at the same time creating an effective barrier to the penetration of rainwater and / or runoff.

The subject of the invention is for this purpose a pressure equalization device sealed against rainwater or runoff for container, characterized in that it comprises a chamber having an external wall, and an internal wall separating it from the container, said chamber communicating on the one hand with the outside via at least one orifice formed in said external wall and on the other hand with the inside of the container by a tube extending through said internal wall and projecting into said chamber, the shape of said internal wall and the position of the orifice of the external wall being such that in any position of the container the orifice or part of it is located at a level lower than that of the end of said tube in bedroom.

In the remainder of this description the term "orifice" should be understood as designating an opening of any shape.

Thanks to this arrangement, a liquid which may have entered the chamber cannot enter the container.

According to another characteristic of the invention, the device comprises a deflecting plate spaced from said external wall and which covers it by providing with it interstices in baffles with the orifices.

According to a preferred embodiment of the invention, said external wall is formed by a part of the wall of the container.

Said internal wall can have any shape. According to a preferred embodiment of the invention, it has the shape of a quarter cylinder. According to another embodiment, it has the shape of a quarter of a sphere.

• La figure 1 est une vue partielle en section d'un conteneur utilisé pour le transport par voie aérienne de matériels fragiles et comportant un dispositif suivant l'invention.
• La figure 2 est une vue en plan de dessus avec arrachement partiel correspondant à la vue de la figure 1.

Other characteristics and advantages of the invention will become apparent during the description which follows, made with reference to the appended drawing given solely by way of example and in which:

• Figure 1 is a partial sectional view of a container used for the transport by air of fragile materials and comprising a device according to the invention.
• FIG. 2 is a top plan view with partial cutaway corresponding to the view in FIG. 1.

Referring to the drawing, there is shown a part of a container having as a whole an approximately parallelepiped shape, of known construction, for example made of a resin reinforced with glass fibers, comprising a lower part 1 and an upper part. 2 kept assembled by conventional means (not shown) comprising a bottom 3, and an upper wall 4 forming cover, sealing means 5 at the junction of the bottom and cover 1 and 2, handling and stowage members 6 and feet 7 or other similar conventional formations on transport containers.

The container shown in the drawing comprises a device for balancing pressure and sealing against rainwater and runoff, which is generally designated by the reference 8. This device 8 comprises a chamber 9 having an outer wall constituted by a part 10 of the wall of the cover 4, this part 10 being slightly set back with respect to the rest of the wall of the cover, thus delimiting a shallow cavity 11, this part of the wall of the cover being located astride two adjacent sides of the wall of the cover, on either side of the upper edge and at approximately equal distance between the two corners of the cover of the container as shown in FIG. 2.

Chamber 9 has an attached internal wall 12 which, according to the example shown, has the shape of a quarter of a sphere.

The internal wall 12 isolates the chamber 9 from the interior volume of the container and is crossed by a radiating tube 13 which makes the interior volume of the container communicate with the interior volume of the chamber 9.

The tube 13 is fixed in a boss 14 of the wall and extends projecting inside the chamber.

The external wall 10 of the chamber 9 is pierced with orifices 16, 16a, 16b, 16c, only two of which are visible in the section of FIG. 1 and which appear in FIG. 2.

• - d'une part au-dessus du ou des plans d'eau pouvant éventuellement s'accumuler dans la chambre quelle que soit sa position,

The end of the tube 15 is located:

• - on the one hand above the body or bodies of water which may possibly accumulate in the room whatever its position,

- on the other hand, at a sufficient distance from the walls of the chamber to prevent the penetration of liquid into said aeration tube 13, due to the front of a possible wave of liquid.

Referring to Figure 2 we see that an orifice 16 is provided in the middle of the semicircle formed by the wall 12, considered in plan, another orifice 16a being provided in the upper part of the external wall 10 in the vicinity of the angle formed by the latter along the edge of the container, a third orifice 16b being provided in the lateral part of the external wall 10, diametrically opposite with respect to the orifice 16a while a fourth orifice 16c is symmetrical with the orifice 16 with respect to the lateral edge of the external wall 10.

It is understood that thanks to the quarter-sphere shape of the internal wall 12 and the location of the orifices 16, 16a, 16b, 16c, a liquid located in the chamber 9 cannot penetrate into the container, whatever its position. In addition, the internal end 15 of the tube 13 in the chamber 9 is always located above one of the orifices 16, 16a, 16b, 16c, whatever the position of the container. It is thus understood that rainwater or runoff which may have entered the chamber 9 can never reach a sufficient level therein to penetrate inside the container via the end 15 of the tube 13.

To further limit the possibilities of penetration of rainwater or runoff into the chamber, it is advantageously provided according to another characteristic of the invention a deflecting wall 18 which covers the external wall 10 while being spaced therefrom as shown in Figure 1, this deflecting wall 18 having as a whole the form of a square whose ends of the wings are rounded and which is fixed by the inner edge of its wings on the periphery 19 of the cavity 11 via d 'spacers 20 by means, for example, of rivets or welding points 21.

It is understood that thanks to this arrangement the deflecting wall 18 delimits with the periphery 19 of the cavity 11 formed in the upper wall 4 of the container an interval whose height corresponds to the thickness of the spacers 20, which thus allows the free passage of the air, while the intervals between the spacers 20 are opposed with respect to the orifices 16, 16a, 16b, 16c so that rainwater or runoff able to penetrate inside the chamber 9 are limited to the quantities which can reach the orifices 16, 16a, 16b, 16c, these extremely limited quantities flowing immediately through these orifices without ever reaching the level fixed by the end 15 of the tube 13.

It is understood of course that the internal wall 12 described as having the shape of a quarter of a sphere, could have a different shape, for example formed by portions of plane forming between them dihedral angles delimiting for example a portion of a polyhedron ( including a cylinder).

It is also understood that it may be provided, if desired, several chambers 9 located at any point on the wall of the container so that the external wall 10 overlaps at least one edge of the latter, said chambers 9 ensuring thus not only the pressure balancing of the containers, but also, in combination therebetween, aeration and / or ventilation of the interior of said container or enclosure.

) Finally, it is understood that the deflecting wall 18 constitutes protection for the external wall 10 of the chamber so that in the event of an impact following rough handling of the container, this wall 10 is protected from any risk of rupture.

The invention thus provides a pressure balancing device which is perfectly sealed against the penetration of rain or runoff water and which is particularly advantageous for being used on containers for transporting fragile materials which can thus be) stored in one direction. any without respecting a predetermined bearing face on the ground and also allowing the air transport of the containers without special protection with regard to pressure variations. Furthermore, the material packed in the container fitted with the device according to the invention is always protected from rain or runoff water, which makes the container suitable for maritime transport even outside the holds. Tests carried out in artificial rain and using abundant watering in all positions of the container have demonstrated a perfect flow of water in the pressure equalization chamber 9 without any penetration of the liquid into the interior of the container by the tube 13.

In a variant not shown, the wall 10 could be nonexistent and thus the chamber 9 would be delimited by the wall 12 and the deflector 18, the interval between the deflector 18 and the wall 4 divided by the spacers 20 delimiting passage sections d water or air guaranteeing the functions of the holes made in the wall 10 of the base solution.

Claims (14)

1. Pressure balancing device sealed against rainwater or runoff, for a transport container, in particular of fragile materials, characterized in that it comprises a chamber (9) having an external wall (10), and a wall internal (12) separating it from the container, said chamber (9) communicating with the outside by at least one orifice (16, 16a, 16b, 16c) formed in said external wall (10) and with the inside of the container by a tube (13) extending through said internal wall and projecting into said chamber (9), the shape of said internal wall (12) and the position of the orifice (16, 16a, 16b, 16c) being such that in any position of the container the orifice (16, 16a, 16b, 16c) or a part of it is located at a level below that of the end (15) of said tube (13), in the chamber. 2. Pressure balancing device according to claim 1, characterized in that it comprises a deflecting plate (18) spaced from said external wall (10) and which covers it by providing therewith interstices in baffle with said orifice (16, 16a, 16b, 16c). 3. Pressure balancing device according to claim 2, characterized in that said external wall (10) is constituted by a part of the wall (3, 4) of the container. 4. Pressure balancing device according to claim 3, characterized in that said part of the wall (3, 4) of the container is recessed with respect to the rest of the wall thereof and delimits therewith a cavity (11). 5. Pressure balancing device according to claim 3, characterized in that said chamber (9) is located on any partje of at least one edge of the container, so that said outer wall (10) overlaps the or said edges. 6. Pressure balancing device according to claim 5, characterized in that said internal wall (12) of the chamber (9) has the shape of a portion of sphere, and preferably a quarter of a sphere. 7. Pressure balancing device according to claim 5, characterized in that said internal wall (12) of the chamber (9) has the shape of a cylinder portion and preferably a quarter cylinder. 8. Pressure balancing device according to claim 5, characterized in that said internal wall (12) of the chamber (9) has the shape of a portion of a polyhedron and preferably a quarter of a polyhedron. 9. A pressure balancing device according to any one of claims 1 to 8, characterized in that said tube (13) projects into the interior of said chamber (9) so that its end 15 is located : - on the one hand above the body or bodies of water which may possibly accumulate in the room whatever its position, - On the other hand, at a sufficient distance from the walls of the chamber to prevent the penetration of liquid into said aeration tube 13, due to the front of a possible wave of liquid. 10. Pressure balancing device according to claim 4, characterized in that said deflecting wall (18) closes said depression (11) and is in the extension of the wall (3, 4) of the container. 11. Pressure balancing device according to claim 3, characterized in that said deflecting wall (18) can constitute the external wall of the combined chamber (9), cavity (11) forming a single space limited only and internally by the internal wall (12). 12. Enclosure equipped with at least one pressure balancing device (8) as claimed from 1 to 11.

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