GB2090142A - Medical sterilisation cases - Google Patents

Abstract

A case comprises a cover portion (C) with a top wall member (2) having a pair of depending side walls (6, 7), a base portion (B) with a bottom wall member having a pair of upstanding front and rear walls and upstanding posts (20) disposed at each side edge of and attached to the front and rear walls. Two handles (30) are pivotally attached one to each side wall (6, 7) of the top wall member (2). Each post (20) comprises a neck portion extending above the upper edge of the associated one of the front and rear walls and a head portion (26) which surmounts the neck portion and projects outwardly of the neck portion at all sides thereof. The top wall member (2) has a pair of recesses at its front edge and a pair of apertures disposed adjacent its rear edge. Each recess and aperture is provided with a concave extension at its rear edge. These extensions are so arranged as to underly the head portions (26) when the case is closed and to prevent upward movement of the top wall member (2). The handles (30) are each pivotable about an axis extending along the associated one of the side walls (6, 7) and, when the case is closed, engage fully between the head portions (26) of a respective pair of the posts (20) and prevent sliding movement of the cover portion (C) relative to the base portion (B). <IMAGE>

Description

SPECIFICATION A case The present invention relates to a case and, more particularly, to a medical device sterilisation case provided with a lockable cover.

In medicine, especially surgery, cases are used to hold articles necessary for operations, for example surgical instruments and prosthetic articles. The cases consist of apertured metal cover and base parts, so that the cases and their contents can be sterilised in advance of an an operation in an autoclave.

In a known case, a base and a cover are connected together at one side by a hinge in the manner of a suitcase and at the opposite side are securable by snap fastenings. In general, several insert elements are arranged one on top of the other inside the case to carry the surgical instruments or other articles.

Sterilisation of the case and contents is carried out by alternately subjecting the case in an autoclave to steam at a temperature of, for example, 140 to 1 450C, and to a vacuum.

When a case of the known type is opened in the course of an operation, the cover remains connected to the base and requires the same amount of space. This is particularly disadvantageous, as during an operation a number of cases with instruments and prosthetic articles are often needed and these instruments and articles should be grouped as closely as possible and be readily at hand for the theatre staff. In addition, the known cases cannot be stacked in a stable manner in either closed or open state, which further hampers their handling during operations.

In general, the unlocking of the snap fastenings for opening such cases presents a degree of inconvenience. It has also proved that the snap fastenings of the known cases do not satisfactorily cope with all the stresses that may arise, especially during sterilisation. The different parts of the fastenings may, for example, be deformed during sterilisation, which has the consequence of making the fastenings very difficult to open or, conversely, of allowing the cases to spring open by themselves when being carried around.

There is accordingly a need for a case with base and cover portions which are easily openabie and completely separable from each other, but which, nevertheless, are firmly secured against accidental opening during transport. Desirably, such a case should also have the capacity of combining with other cases of its kind for formation of a stable stack.

In accordance with the present invention, there is now provided a case comprising a base portion, which comprises a bottom wall member, upstanding front and rear wall members connected to the bottom wall member at, respectively, two opposite side edges thereof, and a respective retaining means arranged at each upstanding edge of the front and rear wall members and comprising a neck portion extending above the upper edge of the associated wall member and a head portion arranged on the neck portion and projecting laterally of the neck portion to at least one side thereof, and a cover portion, which is mountable on the base portion and which comprises a top wall member provided with two recesses open at and extending rearwardly of a front edge of the top wall member and with two apertures which are disposed in the region of a rear edge of the top wall member and which are so shaped as to permit the head portions of the retaining means associated with the rear wall member to pass therethrough in one position of the cover portion relative to the base portion, the neck portions being engageable in the recesses and apertures and so movable therein on slidable displacement of the cover portion towards the front wall member of the base portion as to cause the head portions to be positioned to prevent upward movement of the cover portion away from the base portion, two depending side wall members connected to the top wall member at, respectively, two opposite side edges thereof, and securing means comprising a respective handle mounted on each of the side wall members to be so pivotable about an axis extending parallel to the associated one of said side edges of the top wall member that a portion of the handle is movable into and out of a position in which it engages, when the cover portion is mounted on the base portion, between an adjacent pair of the head portions in such a manner as to prevent slidable displacement of the cover portion away from the front wall member of the base portion.

An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a medical device sterilisation case embodying the present invention, Fig. 2 is a side elevation of the case of Fig. 1 taken from its left hand side, Fig. 3 is a fragmentary plan view of the case showing one of its handles in the unlocking position, Fig. 4 is a fragmentary plan view of the case showing one of its handles in the unlocking position and with the case cover shifted rearwardly, Fig. 5 is a fragmentary front elevation of the case showing one of its handles in the unlocking position, and Fig. 6 is a partially broken away, fragmentary, front elevation of two cases stacked one on top of the other.

Referring now to the accompanying drawings, Figs. 1 and 2 show a medical sterilisation case 1, for example for the sterilisation of surgical instruments and implant items such as bone plates and screws, and/or the retention of such sterilised articles, the case comprising a pair of rectangular, parallelly opposed top and bottom walls 2 and 3, a pair of rectangular, parallelly opposed front and rear walls 4 and 5, and a pair of rectangular, parallelly opposed side walls 6 and 7.

Preferably, the top and bottom walls 2 and 3 are provided with a plurality of apertures 8 to facilitate sterilisation, only a few of which are shown in Fig. 1 for the sake of greater clarity. In the form shown, the front, bottom and rear walls 4, 3 and 5 are formed of a single sheet of metal to provide a base B as are the top and side walls 2, 6 and 7 to provide a cover C.

A post 20 (Figs. 2 and 6) is attached to each side edge of the front and rear walls 4 and 5, such as by screws S to position the cover C (the top and side walls 2, 6 and 7) with respect to the base B (the bottom, front and rear walls 3, 4 and 5) and to aid in locking. Each post 20 comprises a body portion 22 in the form of an upwardly extending, right rectangular prism, a depending foot portion 24 and a head portion 26 connected to the top of the body portion 22 by a cylindrical neck portion 28 of reduced diameter, the head portion thus projecting laterally of the neck portion to at least one side thereof.The body portion 22 of each post 20 forms a corner support for the cover C, the side wall 23 (Figs. 2 and 6) of the body portion 22 facing the depending side wail 6 and 7 acting, along with the side edge of the front and rear walls 4 and 5, to keep the cover C from slipping lateraily. Each neck portion 28 is reduced in diameter and the minimum transverse dimension of the head portion 26 is greater than the maximum transverse dimension of the neck portion 28 so that the head portion projects outwardly at all sides of the neck portion and cutouts 1 Ob and 1 2b provided in the top wall 2 can rest against the neck portion 28, while the head portion 26 prevents upward movement of the top wall 2.The head portion 26 is square in plan view (Figs. 3 and 4), but has its upper surface convexly curved in side elevation (Figs. 2, 5 and 6) and is provided with a centrally disposed, hemispherically bottomed recess 27 (Figs. 3 and 4), so that a plurality of cases 1 and 1' (Fig. 6) may be stacked without being free to shift horizontally relative to one another. The foot portion 24 is of a shape complementary to that of the recess 27 in that it is generally cylindrical with a hemispherical tip. Each post 20 is secured to its respective front or rear wall 4 or 5 by a plurality of screws S.

As may be seen from Figs. 3 and 4, the top wall 2 is provided with a pair of recesses 10 at its front edge and a pair of apertures 12 in the region of its rear edge. As will be further explained, the recesses 10 and apertures 12 can so co-operate with the posts 20 that the base portion B and cover portion C can be locked together when the case is closed but separated from each other for opening of the case. Each recess 10 O is open at its front to the front edge of the top wail 2 and has parallel side edges 1 0a (Fig. 4) extending rearwardly from the front edge to a rear edge which has an offset concave, preferably semicircular, cutout or extension lOb.Each aperture 12 is generally square in plan view except for its rear edge 1 2a (Fig. 4) which has a centered concave, preferably semicircular, cutout or extension 12b. Each aperture 12 is so shaped and dimensioned as to permit the head portion 26 of a post 20 to pass axially through it. The depth of the recess 10 is less than the corresponding dimension of the aperture 12, i.e. the distance from the rear edge of the cutout 1 Ob to the front edge of the top wall 2 is less than that from the rear edge of the cutout 1 2b to the front edge of the aperture 12. The distance between the adjacent side edges 1 Oa of the two recesses 10 is approximately equal to the distance between facing points on the neck portions 28 of the two posts 20 at the front wall 4.The distance between the facing side edges of the two apertures 12 is, at the most, approximately equal to the distance between facing side edges of the heads 26 of the posts 20 at the rear wall 5. In addition, the distance between the two furthest apart side edges of the two apertures 12 is at least approximately equal to the distance between the mutually remote side edges of the associated pair of head portions 26. Whereas the recesses 10 are narrower overall than the corresponding dimension of the head portions 26, the distance between mutually opposite edges of each opening 12 is at least equal to the corresponding dimension of the head portions 26.Thus, if the top wall 2 is disposed in the position shown in Fig. 4 in which it can be lifted at its rear edge so that the apertures 12 pass upwardly over the head portions 26 of the rear posts 20, the recesses 10 and front edge of the top wall 2 are not yet free of the head portions 26 of the front posts 20.

A handle 30 (Figs. 1 and 2) is pivotally attached by a hinge 36 to the upper edge of each side wall 6 and 7 with its axis of pivotation and its longitudinal dimension extending parallelly to the longitudinal dimension of the side wall, to which it is secured by fasteners 38. The handle 30 is generally L-shaped in end view (Fig. 5) with a depending lip 34 and a top plate 32, which has a length (Fig. 2) approximately equal to the distance between the facing side faces of the head portions 26 of the respectively associated front and back posts 20.

With the cover C in its closed and locked condition (Figs. 1 and 2), the case 1 has the shape of a right rectangular prism and the neck portions 28 of the two front posts 20 rest within the offset cutouts 1 Ob of the two front recesses 10 and the neck portions 28 of the two rear posts 20 rest within the centered cutouts 1 2b of the two rear apertures 12 so that the head 26 of each post 20 prevents upward movement of the cover C, i.e. the top wall 2 and its associated side walls 6 and 7, relative to the base B. In this closed and locked condition, the top plate 32 of each handle 30 is disposed between a front and rear post 20 in generally parallel relation to the top wall 2 so that each top plate 32 and its associated front and rear posts 20 prevent rearward shifting of the cover C.

The hinges 36 preferably have a light selflocking facility so as to retain the handles 30 in a locking or unlocking position. Thus, if the handles are manually pivoted into the locking position they are held in this position until manually released. If the outwardly projecting portions of the handles are lifted for carriage of the case, the resulting moments of the handles about the hinge axes cause the top plates 32 to press down onto the top wall 2.

In order to open the case 1, the two handles 30 must be moved into their unlocking position by pivoting their lips 34 downwardly and top plates 32 upwardly (Figs. 3 and 5). This cannot be done easily when the case 1 is supported by its handle 30, thereby providing a safety feature to prevent unintentional opening of the case 1 while it is being carried. When the handles 30 are so pivoted with the top plates 32 lifted clear of their interference with rearward shifting of the cover C, the cover C is slid rearwardly until the rear edge 1 2a of each rear aperture 12 clears the rear.edge of the head portion 26 of each rear post 20 (Fig. 4). At this point, the front edge of the top wall 2 has not cleared the rear edge of the head portion 26 of each front post 20.Next, the rear edge of the top wall 2 is pivoted upwardly using the line of contact between the top wall front edge and the front post body upper surface as the pivot. During this operation, the handles 30 may remain in their upward, unlocking position or they may be pivoted back initially partly and then fully to their downward locked position to provide a more secure grip on the cover C in subsequent operations. As soon as the front edge of each rear aperture 12 clears the top surface of its associated rear post 20, the top wall 2 is slid rearwardly again until its front edge clears the rear edge of each front post 20. Alternatively, these two pivoting and sliding operations may be combined in one operation with both movements proceeding concurrently.At this point, the rearward motion is continued (or alternatively, the cover C is lifted upwardly) to remove the cover C from the case 1.

In order to close and lock the case 1, the foregoing operations are carried out in reversed sequence.

The case shown in Figs. 1 to 6 is especially suitable for use in the medical field and serves for holding surgical instruments and/or prosthetic items, the case being designed so that, together with its contents, it can be placed in an autoclave and sterilised therein. Sterilisation can take place, for example, by subjecting the case and contents alternately to steam and a vacuum. The steam and the air or gas used can flow into and out of the case via the apertures 8.

If, after sterilisation, the case is to be used in connection with an operation, the cover 6 can be opened and completely removed from the base B and can be placed wherever desired. As already mentioned, a number of such cases can be arranged in a stable stack, and the bases of such cases can, of course, be similarly stacked without their covers.

The base B, cover C, handles 30 and hinges 36 preferably consist of a corrosion-resistant metal, for example the base and cover may be made of aluminium and the handles and hinges of stainless steel. The posts 20 can be made of a plastics material, for example polyamide.

While the present invention has been described in the context of its preferred embodiment, a medical device sterilisation case, the term "case" should be understood to include other cases for retaining articles during carriage.

Claims (10)

1. A case comprising a base portion, which comprises a bottom wall member, upstanding front and rear wall members connected to the bottom wall member at, respectively, two opposite side edges thereof, and a respective retaining means arranged at each upstanding edge of the front and rear wall members and comprising a neck portion extending above the upper edge of the associated wall member and a head portion arranged on the neck portion and projecting laterally of the neck portion to at least one side thereof, and a cover portion, which is mountable on the base portion and which comprises a top wall member provided with two recesses open at and extending rearwardly of a front edge of the top wall member and with two apertures which are disposed in the region of a rear edge of the top wall member and which are so shaped as to permit the head portions of the retaining means associated with the rear wall member to pass therethrough in one position of the cover portion relative to the base portion, the neck portions being engageable in the recesses and apertures and so movable therein on slidable displacement of the cover portions towards the front wall member of the base portion as to cause the head portions to be positioned to prevent upward movement of the cover portion away from the base portion, two depending side wall members connected to the top wall member at, respectively, two opposite side edges thereof, and securing means comprising a respective handle mounted on each of the side wall members to be so pivotable about an axis extending parallel to the associated one of said side edges of the top wall member that a portion of the handle is movable into and out of a position in which it engages, when the cover portion is mounted on the base portion, between an adjacent pair of the head portions in such a manner as to prevent slidable displacement of the cover portion away from the front wall member of the base portion.

2. A case as claimed in claim 1, wherein each of the retaining means comprises a post arranged at a respective corner of the bottom wall member and rigidly fastened to the associated one of the front and rear wall members at an inwardly facing side thereof.

3. A case as claimed in either claim 1 or claim 2, wherein each of the head portions projects outwardly of the associated neck portion to all sides thereof.

4. A case as claimed in any one of the preceding claims, wherein each of the recesses and apertures includes, at a side thereof remote from the front edge of the top wall member, a portion which is of reduced width in relation to the remaining portion of that recess or aperture and which receives a respective one of the neck portions when the cover portion is mounted on and secured to the base portion.

5. A case as claimed in claim 4, wherein each of the head portions has a substantially rectangular outline in plan, said remaining portion of each aperture being of corresponding rectangular outline.

6. A case as claimed in either claim 4 or claim 5, wherein the dimension of each recess in a direction parallel to said side edges of the top wall member is less than that of each aperture in the same direction by such an amount that, when the head portions of the retaining means associated with the rear wall member are aligned for passage through the apertures, the front edge of the top wall member is so supported by surface portions at the bases of those neck portions engageable in the recesses as to permit pivotable movement of the cover portion upwardly away from the base portion about said front edge.

7. A case as claimed in any one of the preceding claims, wherein the distance separating the two recesses is substantially equal to the distance separating the two neck portions of the retaining means associated with the front wall member, and the distance separating the two apertures is smaller than the distance separating the two head portions of the retaining means associated with the rear wall member.

8. A case as claimed in any one of the preceding claims, wherein the length of said portion of each handle is substantially the same as the distance separating the head portions between which that handle portion is engageable.

9. A case as claimed in any one of the preceding claims, wherein each of the retaining means further comprises a foot portion to support the base portion, each of the head portions being provided with a depression for receiving the foot portion of a retaining means of another such case.

10. A case as claimed in any one of the preceding claims, wherein at least one of the top and bottom wall members is provided with openings to facilitate the flow of a sterilising medium into or out of the case for the sterilisation of articles therein.

1 A case substantially as hereinbefore described with reference to the accompanying drawings.