EP0200579B1 - Device for storing tubes in a cryogenic vessel - Google Patents

Abstract

Each module (1) of this device comprises a bin (4), two removable drawers (5) and a removable intermediate partition (7). When the two drawers are in position, tubes (2) of small height can be stored. When the upper drawer and the partition (7) are withdrawn, tubes (3) of greater height can be stored. Each drawer is provided with a grating (6) for laterally maintaining the tubes. Application in the storage of biological specimens in liquid nitrogen.

Description

The present invention relates to a device for storing in liquid nitrogen tubes having different stirrers, device of the type comprising a superposition of removable drawers sliding in a chassis, this chassis comprising at least one rack suitable for receiving at least two drawers . It applies in particular to the storage of biological products in liquid nitrogen.

The tubes intended for the cryogenic storage of biological products such as animal or human seeds normally have a standard diameter but different heights, corresponding to samples of 2 ml and 5 ml. It is therefore currently necessary to have two types of storage devices, one for each type of tube.

A known device of the aforementioned type, described in DE-A-2 528 152, is not suitable for immersion in liquid nitrogen, because if a drawer is removed, the tubes contained in the drawer located below are no longer held up.

The object of the invention is to provide a storage device offering great flexibility thanks to the possibility of storing simultaneously and in variable proportions in liquid nitrogen the two types of tubes.

To this end, the invention relates to a storage device of the aforementioned type, characterized in that the rack comprises a removable horizontal intermediate partition adapted to be placed between the two drawers and which, in this position, supports the upper drawer and retains the tubes contained in the lower drawer.

Preferably, to ensure good support of the tubes, each drawer is provided, at an intermediate height, with a grid for positioning the tubes, this grid comprising, for each tube, a hole which can be freely traversed by it and surrounded by reliefs for lateral support of the tube. It is then advantageous that the grid is removable and rotatable. These arrangements are known in the evening from US-A-3 113 689.

• - la figure 1 est une vue de face, avec arrachements et coupe partielle, d'un module d'un dispositif de stockage conforme à l'invention, illustré dans deux configurations différentes d'utilisation;
• - la figure 2 est une vue partielle en perspective éclatée du module de la figure 1; et
• - la figure 3 est une vue partielle en plan d'une grille de positionnement des tubes.

An exemplary embodiment of the invention will now be described with reference to the appended drawing, in which:

• - Figure 1 is a front view, with cutaway and partial section, of a module of a storage device according to the invention, illustrated in two different configurations of use;
• - Figure 2 is a partial exploded perspective view of the module of Figure 1; and
• - Figure 3 is a partial plan view of a grid for positioning the tubes.

The storage module 1 shown in the drawing is intended to hold a number of tubes 2, 3 for preserving biological products in a container (not shown) filled with liquid nitrogen. In practice, several modules 1 are stacked and fixed to each other, for example by welding or clipping, to occupy the entire height of the container, the upper module being equipped with a handle. In addition, although the module 1 shown has, in plan, a rectangular shape, it can also have another shape, for example triangular, so that all the stacks of modules make the best use of the space available in the container.

The module 1 comprises a rack 4, two drawers 5 each equipped with a grid 6 (the upper drawer and the grids 6 have not been shown in FIG. 2, for the sake of clarity of the drawing), and a partition 7 All these elements are made of a plastic material adapted to withstand cryogenic temperatures.

The tubes 2 and 3 have a common diameter, but the tubes 3 have a height approximately twice that of the tubes 2. They are intended to store samples of 2 ml (tubes 2) and 5 ml (tubes 3) respectively.

The locker 4 is parallelepiped and open on its front face. Its upper and lower faces are full, and its three other faces largely perforated by pairs of windows 8 separated by horizontal members 9 located halfway up the rack. Each lateral member has an internal groove 10, and the rear member has a snap-in recess 11.

Each drawer 5 is open upwards. Its front face 12, of reduced height, has a central tab 13 for gripping. On its inner periphery, the drawer has a number of vertical ribs 14 extending approximately halfway up. Furthermore, although this is not shown, the drawer has at its bottom at least one opening for draining liquid nitrogen, and also external snap reliefs for keeping it in position in the rack.

Associated with each drawer is a grid 6, a corner of which is shown in FIG. 3. This grid comprises a large number of circular trQUS 15 whose diameter is slightly greater than that of the tubes 2 and 3 - and, between these holes, a large number of cylindrical pins 16 arranged in a picot manner is slightly less than half that of a drawer.

The partition 7 is a rectangular plate, the lateral edges of which are adapted to slide in the grooves 10 of the rack and the rear edge of which has a latching relief 17 in the recess 11.

In a first mode of use of module 1, illustrated on the left half of the figurel, tubes 2 of 2 ml are socked. In each of the two drawers, the corresponding grid 6 is placed on the ribs 14, with the pins 16 facing downward, and the tubes 2 are placed in the hole 15. Thus, each tube 2 is held in vertical position and can easily be grabbed by its upper part to be extracted.

The partition 7 is put in place, the lower drawer 5 is inserted under it, pressing on the lower bottom of the rack 4, and the upper drawer 5 is inserted above the partition, pressing on this one. The height of the tubes is such that each rests on the bottom of the corresponding drawer and rises to a level slightly lower than the wall which surmounts it: the partition 7 for the lower tubes 2, the upper wall of the rack 4 for the upper 2 tubes.

When all of the modules 1 are immersed in liquid nitrogen, the tubes 2 tend to float on this liquid and therefore to rise. They are retained vertically, one by the partition 7, the other by the upper wall of the crate, and laterally by the pins 16 (which, as a variant, could be replaced by cylindrical collars). It can be seen that one or the other of the drawers 5 can be extracted without disturbing the positioning of the tubes 2 of the other drawer, thanks to the double role of the partition 7: support of the upper drawer on the one hand, retained vertical of the lower tubes on the other hand.

The other mode of use of the module 1, used for the storage of tubes 3 of 5 ml, is illustrated in the right half of Figure 1: the upper drawer is removed, and the grid 6 of the lower drawer is supported on the ribs 14 of the latter, but this time with the pins 16 facing upwards. The long tubes 3 are arranged in the holes 15 and extend from the bottom of the lower drawer to a location close to the upper wall of the rack 4. More precisely, the distance separating this wall from the upper end of the tubes 3 is significantly lower than that which separates the bottom of the drawer from the top of the pins 16.

When the module is immersed in liquid nitrogen, the tubes 3 tend to float on this liquid and therefore to rise, but they are held vertically by the upper wall of the crate 4 and guided laterally by the pins 16. Thus, from again, the arrangement of the tubes is not disturbed.

It can be seen that there is thus a very flexible storage device making it possible to store tubes of different lengths. With different diameters, these tubes could also have three drawers and two intermediate partitions, to further increase the possibilities of use.

Claims (4)

1. Device for storing tubes (2, 3) of different heights in liquid nitrogen, in particular for storing biological products in liquid nitrogen, of the kind comprising a set of superposed removable drawers (5) sliding in a framework, this framework comprising at least one bin (4) adapted to receive at least two drawers (5), characterised in that the bin comprises a removable intermediate horizontal partition (7) adapted to be positioned between the two drawers (5) and which, in this position, supports the upper drawer and retains the tubes contained in the lower drawer.

2. Device according to claim 1, characterised in that each drawer (5) is provided at an intermediate height with a grating (6) for positioning of the tubes (2, 3), this grating comprising for each tube, a hole (15) which may be traversed freely by the latter and which is enflanked by projections (16) for lateral retention of the tube.

3. Device according to claim 2, characterised in that the grating (6) may be removed and turner over.

4. Device according to any one of the claims 1 to 3, characterised in that it comprises a set of superposed bins (4) secured to each other, the top bin being provided with a grasping handle.

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