GB2215347A - Isolators - Google Patents

Abstract

Bubble isolators incorporate inside themselves on their floor one or more tray of some suitably strong or tough material, such as polyethylene or stainless steel. However, the size of each tray is limited by the size of the bubble's hatch-way, and the whole is necessarily rather difficult to clean in situ, especially underneath each tray, by the normal sterilizing methods. The invention comprises a modified construction of isolator with a two-part structure, having a canopy (12) and a tray-like base (11), and that the two be detachably sealed to each other around their respective perimeters to produce the isolator, the seal being secured by a special long but flexible clip-like device (17). <IMAGE>

Description

Isoiators This invention reiates to isolators, and concerns in particular the construction of isolators in two sections sealingly joined together.

In many fields of technology there is a need for ork to be carried out in an environment that is safely sealed off from the rest of the world. For example, in the biological sciences it is common to work with dangerously toxic or infectious materials (such as poisons, bacteria or viruses) and it will usually be desirable to carry out this work in a fully enclosed area from which the dangerous materials cannot easily escape into, and so contaminate, the surroundings. In the pharmaceutical and electronics industries, on the other hand, it may be desirable to wo on some product csuch as a drug or microchip) within a scrupulously clean enclosure, so as to prevent the ambient conditions contaminating the product.

Both of these situations require a volume of space to be sealed off - isolated - from its surroundings, and to meet this need technology has produced the isolator, which comes in sizes varying from that of a large (lxlxl m, or about 2.5x2.5x2.5 ft) box up to that of a smail room) In essence, an isolator is little more than a sealed, bubble-like envelope in the wall of which is both a hatch (though which articles can be passed in and out) as well as means whereby the bubbles contents can be manipulated.The envelope is naturally made oT some (preferably transparent) material suitably resistant to whatever chemicals and other substances are likely to come into contact with it both inside and outside the isolator (typical such materials are flexible polyvinyl chloride - PVC - film or sheet, but some isolators can be made of rigid materials such as a glass).One very successful form of isolator available today is a cuboidal "burble" of flexible PVC suspended from an external framework that both shapes and supports the bubble Such a bubble isolator is both effective and relatively inexpensive, but it does have one major disadvantage, which is that the material forming the envelope wall - Plt sheet, perhaps - is, particuiarly on the isolator floor, too easily torn, cut or otherwise damaged by equipment used inside the bubble.One answer to this problem is to place inside the bubble on its floor one or more trays of some suitably strong or tough material, such as polyethylene or stainless steei, but not only is the size of each tray limited by the size of the bubble's hatch-way but the under surface of the tray, and the surface of the bubble floor on which the tray sits, is necessarily rather difficult to clean in situ by the normal sterilizing methods.

The present invention proposes that this problem be avoided by a modifies construction of isoiator.

Specifically, the invention suggests that the isolator be a two-part structure (instead of a one piece bubble), having a canopy, or upper tent-like part, similar to the conventional bubble envelope, and a base, or lower traylike part, similar to the conventional trays for internal use, and that the two be detachably sealed to each other around their respective perimeters to produce the isolator, the seal being secured by a special long but flexible clip-like device.

In one aspect, therefore, this invention provides an isolator having a tray-like base portion of a generally rigid physically and chemically resistant material upon which is sealing mounted around the edges thereof a tent-like canopy portion of a flexible and transparent chemically resistant material, the manner of this mounting being such that the canopy's free (lower) edge ic fole around and under the base's edge (the lip) and is then held in place by one or more clip-like device each of which is b single longitudinally-extended cli fleibl no enough to extend all the way round the baes's edge.

Apart rrom its two-portion construction - the canopy sealingly mounted on the base - the isolator ol the invention is in general quite conventional. It is, however, discussed further in this respect hereinafter.

The inventive isolator has a base portion tnat is trays ire - that is to say, has a "floor" that extends over an area (conveniently oblong) and has a slightly raised perimeter wall with an outwardly directed lip generally parallel to the floor.

The extent of the upward displacement of the lip will be small relative to the dimensions of the floor.

A tray-like base portion l m (2.5 ft) long will conveniently have its wall lip raised about 2.5 cm C1 in) about its floor (or, conversely, it may be regarded as having its floor dished down that distance).

The tray-like base portion is generally rigid, and physically and chemically resistant to the expectea environment (and equipment and other items) within the isoialor. It may be made of any of the materials commonly employed to make the rigid trays already useo in isolators - thus, synthetic resins (such as polyethylene or polypropylene), a glass-fibre reinforced resin, and metals or coated metals (such as aluminium, stainless steel, or an enamelled or plastics-coated mild steel?.

Sealir:Dly mounted (in use) on the tray-like bass portion is the tent-like Cor bell-like) canopy portion.

More speciti cally, the canopy is mounted, at its free (lower) wedge, at the perimeter - the lip - of the trays like base. Though this mounting could conceivably be permanent, with the canopy fixedly bonded to the tray, it is in fact releasabie, so that at times - perhaps for an especwaily thorough cleaning - the canopy and base can e completely separated.

The canopy is flexible, and is sealing mounted on the tray-like base by first folding the free (lower) edge around and sunder the base's edge (the lip) and then holding the folded material in place with clip-like devices. Though each clip-like device could be a short spring clip (like a BULLDOG clip), there being several of these spaced around the base's edge so as to make a good seal between base and canopy, it is a feature of the invention that the (or each) clip-like device is either a single longitudinally extended clip flexible enough to extend ail the way round the base (and especially round the bases corners) or a somewhat shorter clip that is yet long enough to extena ail along one side of the iso valor This ensures a gooc base/canopy seal. Sealing strips of this nature are commonly available (in the motor car industry, for example) for securing two surfaces, one of which may be flexible, to each other. They are usually made of a stiff rubber-iike material with a U-channel section, often with some internal (metal) stiffening to bias the channel mouth edges towards each other.A particularly preferred sealing strip of this kind is one having an internaily-directed "barb" aiong the entire internal length of one side of the U-channel; the barb reduces the tendency of the strip to slide off the two "clipped" surf aces.

Though the use of a single long such ciip, or two, three or four shorter ones, will allow a gooc sea of the canopy to the tray, it may be preferred to provide at each of the tray's corners an additional, short, clip - especially one curved to fit the corner - on ro of (thus, as weii as)-the Cor each) long clip.

The canopy is made of a flexible material, and therefore needs some support in use. This support can be provided by positive overpressure within the rubble (so it is blown up, and stays up, rather like a balloon), but is more conveniently achieved by a framework, especially an external framework from which t canopy is siung. The framework may take the genera form of those already in use with conventional bubole isolators, and can be made of suitable plastics or metal (eg, stainless steel) rods and corner pieces (like the frame of a frame tent).The canopy may be attached to the framework in any convenient, way, such as by ties, but preferably it is by loops of material securec by press stud.

The tent-like canopy portion is generally iieibie, transparent, and chemically resistant to the expected envlronment within the isolator. Like the base portion, it too can be made of any of the materials commonly employed as the envelope of a "bubble" isolator especially flexible PVC fiim or sheet.

As stated above, the isolator of the invention is, apart from its two-piece structure of canopy and base, generally quite conventional. It will therefore usually have a hatchway (and corresponding hatch), through which items can be placed in or removed from the interior, anc manipulating means. For a small isolator, or glove box, the manipulating means will normally be a pair OT sleeves w th gloves on the "hand" end, sealingly mounted at the "shoulder" end in the canopy wall and oDen t the outside. The operator simply inserts his hanos and arms into the sleeves and along and into the gloves. He may then relatively freely manipulate the contents of the isoiator.

An embodiment of the invention is now described, though only by way of illustration, with reference to the accompanying diagrammatic Drawings in which Figure 1 shows a perspective view from above and one end of a glove box isolator of the invention; Figure 2 shows (partly in see-through form) an end elevation of the glove box isolator of Figure 1; and Figure 3 shows (in "exploded" form) a detail of Figure 2.

The isolator (generally 10) shown in the Drawings has a rigid tray-like base part (11) onto wnicn is sealingly mounted a transparent flexible rent-like canopy part (12).The canopy 12 is supporter. in place above the tray via ioops (52) by a franewor. C5) the crossbars (51) of which also support the tray 1 . The tray 11 is oblong, and has a floor (i3), a perimeter wail (14), and a lip (15). The canopy 12 is cuboidal (matching the tray 11 dimensions), and is sealingly mounted on the tray by having its open eno edge (16; see Figure 3) folded around the tray's lip 15 and held in place by an extended U-channel trim-strip clip (i7; not shown in Figure 1) that runs all the way round the base.

The trim-strip 17 is prevented from sliding easily off the lip-folded-over canopy edge combination by an inwardly directed barb (18).

The glove box has the usual glove pair (generally 19) and hatch and hatchway (20).

Claims (10)

1. An isolator having a tray-like base portion of a generally rigid physically and chemically resistant material upon which is sealingly mounted around the edges thereof a tent-like canopy portion of a flexible and transparent chemically resistant material, the manner of this mounting being such that the canopy's free (lower) edge is folded around and under the base's edge (the lip) and is then held in place by one or more clip-like device each of which is a single longitudinally-extended clip flexible enough to extend all the way round the bases's edge.

2. An isolator as claimed in Claim 1, wherein the base portion has a "floor" that extends over an area and has a slightly raised perimeter wall with an outwardly directed lip generally parallel to the floor, the extent of the upward displacement of the lip being small relative to the dimensions of the floor.

3. An isolator as claimed in Claim 2, wherein the tray-like base portion has its wall lip raised 2.5 cm (1 in > above its floor.

4. An isolator as claimed in any of the preceding Claims, wherein the tray-like base portion is made of stainless steel.

5. An isolator as claimed in any of the preceding Claims, wherein the clip-like device is a single longitudinally extended clip flexible and long enough to extend all the way round the base.

6. An isolator as claimed in any of the preceding Claims, wherein the or each clip-like device is made of a stiff rubber-like material with a U-channel section, with some internal stiffening to bias the channel mouth edges towards each other, and an internally-directed "barb" along the entire internal length of one side of the U-channel.

7. An isolator as claimed in any of the preceding Claims, wherein there is provided at each of the tray's corners an additional, short, curved clip on top of (thus, as well as) the (or each) long clip.

8. An isolator as claimed in any of the preceding Claims, wherein there is an external framework from which the canopy is slung.

9. An isolator as claimed in any of the preceding Claims, wherein the canopy portion is made of flexible PVC film or sheet.

10. An isolator as claimed in any of the preceding Claims and substantially as described hereinbefore.