TECHNICAL FIELD

The present invention relates to an apparatus for the safekeeping of film sheets before, during and after expo- sure thereof in, for example, an X-ray camera, the apparat being in the form of a box of great length and width and low height, and the box hav ng an openable and closable l id. ^{' ■}

THE STATE OF THE ART/TECH ICAL PROBLEM

One of the methods for investigating the presence of cancer of the breast in ^' wom-sn is ammograph , i.e. breast X-rays. Because of the high frequency of cancer of the breast in women, primarily in the age group between 35 and 69 years, it is desirable to be able to examine women in th risk zone at least every other ye&r, which would entail 850 000 examinations per year in Sweden alone. Each examin ation comprises from 2 to 3 images taken per breast and present installations have a apacity of from 4 to 5 such examinations per hour. Furthermore, it is desirable that one edge of the image be located as close to the ribcage as possi le, w e eby the probabil i y of photograp ing the entire breast is greatly i proved. ^*

Thus, there is a need bo h of improved aids and more

effective equipment in this art.

These needs are now satisfied according to the present invention in that the apparatus disclosed by way of intro¬ duction is characterized in that the bottom and at least on side wall, which is preferably a longitudinal side wall, are disposed integrally with one - anothe , the longitudinal side wall consisting of a strip bent at a right angle to the bottom _. . Preferably, the lid is fixedly secured to the above-mentioned longitudinal side wall by the intermedi of a film hinge and, on the inside, displays a compression pad for urging of the film sheet against the bottom. At the edge opposed to the hinge, the lid is ^" provided with locking means for cooperation with locking means in the bo ADVANTAGES An apparatus or cassette according to 'the present invention is extremely simple to handle, primarily from the loading nad unloading points of view. Furthermore, the apparatus or cassette according to the present invention allows for extremely close abutment .agai nst the ribcage and almost totally lacks image-restr ct ng parts. DESCRIPTION OF THE ^" ACCOMPANY ING DRAWINGS

Fig. 1 is a schematic perspect ve view of one embodi¬ ment of an apparatus according to the present invention. Fig. 2 shows, on a larger scale, a top plan view of the apparatus of Fig. 1, certain parts having been broken away. Fig 3 is a section taken along the line A-A in Fig. 2. Fig. 4 shows, on a larger scale, ^' a part section of the apparatus of Fig. 3.

As will be apparent to the skilled reader of Fig. 1, an apparatus according to the present invention is in the form of a box 1 with an openable and closable lid 2. The box 1 is of great width and ienσth while being of low hei ght .

Figs. 2 to 4 show the box 1 in greater detail . The bottom 3 and one longitudinal side wall 4 of the box con¬ sist preferably of a rigid carbon fibre material, a materia which has proved to have excellent properties in conjunctio

with X-ray photography. The remaining side walls o ^* box 1 consist of an aluminium frame with a locking lug 6 at the end of the short side walls opposed in relationship to the longitudinal side wall 4, only one locking lug 6 being i 11 ustrated ^■ i n the Fig. 2, whereas the other is merely intimated. The locking lugs are urged towards the closing position by means of locking springs 7 and, in the aluminium frame, there are provided, in register with the locking lugs δ, recesses for the passag of a pin 3 for removal of the locking lugs from their closing position in engagement with a corresponding _. , fixed locking lug 9 on the lid 2. Furthermore, -in the aluminium frame 5 there is provided an opening spring 10. aAl though but one single spring 10 is illustrated on the Drawing, there may, natura lly, be provided one opening spring 10 in each short side wal 1.

The lid 2 consists of a so-called sandwich constructi preferably of aluminium and polyethylene. On the inner side of the lid 2, there is fixedly disposed a compression pad 11 which serves to compress a film sheet 14 against th bottom 3 and against the inside of the longitudinal side wall 4. As ^' will b apparent to the skilled reader of Fig. 5, the lid 2 is mounted on the longitudinal side* wall 4 by the intermediary of a film hinge 12 of per se conventional ^• type. The lid 2 *proper may be fixedly disposed on one of the hinge portions by means of rivets 13.

For loading the cassette 1 , 2 with a sheet of film 14 the sheet may be inserted into a loading apparatus through an opening with light-tight edges. After- passage through the opening, pins 8 on a holder will extend into holes in register with the locking lugs 6 and move the locking lugs 6 out of engagement with the locking lugs 9, whereby the lid 2 .will be opened and moved into the loading position by means of the spring or springs 10. The holes in regist with the locking lugs 6 are located more proxi ally the lower edge than the upper edge, whereby the cassette canno be opened if it is inserted into the apparatus turned in

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incorrect direction. Naturally, this is of particuTar importance on opening of the cassette after exposure of the film sheet. When gripping devices in the apparatus release a sheet of film, the sheet will fall down onto a table and slide into the cassette 1, 2.

On closure of the lid 2 on the film cassette, the compression pad 11 will move the sheet of film 14 into abutment with the longitudinal side wall 4, whereby the position of the sheet of film 14 against the longitudinal side wall 4 will be ensured.