X-Ray Sheet Film Cassette

The present invention relates generally to an X-ray sheet film cassette. More particularly, it relates to an X-ray sheet film cassette which has an upper cassette part and a lower cassette part turnably connected with one another, wherein the lower cassette part includes a thick hard foam intermediate plate part and two thin, thermoplastically bonded carbon fiber outer cassette parts.

X-ray sheet film cassettes of the above mentioned general type are known in the art. One of such cassettes is disclosed, for example, in the German document DE-GMS 88 10 348. In the cassette disclosed in this reference the above mentioned sandwich plate composed of two thin, thermoplastically bonded carbon fiber plates with a thick hard foam plate therebetween, is connected to a frame by welding, adhesive or injection molding. Thereby the contact or adhesive surface between the sandwich plate and the frame which surrounds it is very low. Moreover, there is the danger that during a long use of the X-ray sheet film cassette, the glued, welded or injection molded frame can be released from the sandwich plate.

Accordingly, it is an object of the present invention to provide an X-ray sheet film cassette which avoids the disadvantages of the prior art.

In keeping with these objects and with others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in an X-ray sheet film cassette of the above mentioned type in which in the sandwich plate at least one outer plate extends outwardly beyond the intermediate plate at least at one edge of the plate and more particularly is bent upwardly toward an interior of the X-ray sheet film cassette so as to form a web.

When the X-ray sheet film cassette is designed in accordance with the present invention, the plate of the lower cassette part is connected with the surrounding frame in a stable and durable manner.

Moreover, the plate also has an increased torsion strength.

In accordance with another feature of the present invention, the outer plate part which faces toward the outer side of the X-ray sheet film cassette is bent to extend outwardly beyond the intermediate plate part to form a web.

Still another feature of the present invention is that the outer plate part which faces the inner side of the X-ray sheet film cassette is bent to extend above the intermediate plate part and to form the web.

Also, both outer plate parts can be bent to extend outwardly beyond the intermediate plate part and to form together the web.

Still a further feature of the present invention is that the second web can be provided on the plate so as to extend parallel to the first web, and the second web is arranged at the opposite edge of the plate.

The plate can be connected with the frame by welding, adhesive or formed as a one-piece integral member by injection molding.

The plate can be provided with a camber directed to the interior of the cassette.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

FIG. 1 is a perspective view which shows an X-ray sheet film cassette in accordance with the present invention which is open and the view is partially broken;

FIG. 2 is a view showing the inventive X-ray sheet film cassette in a section taken along the line II--II in FIG. 1;

FIG. 2a corresponds to the view of FIG. 2 and shows another modification of the inventive X-ray sheet film cassette;

FIG. 3 is a view showing the inventive X-ray sheet film cassette in a section taken along the line III--III in FIG. 1;

FIG. 4 is a view showing a portion of the inventive X-ray sheet film cassette of FIG. 1 on an enlarged scale in accordance with one modification of the present invention;

FIG. 5 is a view substantially corresponding to the view of FIG. 4 but showing another modification of the present invention;

FIG. 6 is a view substantially corresponding to the view of FIG. 4, but showing still a further modification of the present invention and

FIGS. 7a-7c show a further modification of the invention.

An X-ray sheet film cassette in accordance with the present invention includes a lower cassette part which is identified as a whole with reference numeral 1 and an upper cassette part which is identified as a whole with reference numeral 2. The lower cassette part 1 and the upper cassette part 2 are pivotally connected with one another by a hinge 3.

The cassette in accordance with the present invention further has locking elements for the upper and lower cassette parts which are identified with references 4 and 4a. The upper cassette part 2 is provided with a reinforcing web 2a. A thermoplastic plate 8 is welded to the reinforcing webs 2a. A pressing pad 6 is mounted on the thermoplastic plate 8. A reinforcing foil 5 is arranged on the pressing pad 6. An X-ray film identified with reference numeral 7 is located between the reinforcing foil 5 and the lower cassette part 1.

The novel feature of the cassette in accordance with the present invention is that it has a plate 1a which is provided at its edge with a web 1e. The plate 1a has two thermoplastically bonded carbon fiber plate parts 1c. The web 1e is formed by one of the plate parts 1c as shown in FIGS. 2 and 3 or by two plate parts 1c as shown in FIG. 6.

The plate 1a can be connected with the lower cassette part 1 by welding or glueing. The welding seams between the cassette part 1 and the plate 1a or the web 1e are identified as 1b. It is also possible to introduce the plate 1a in an injection mold for the lower cassette part 1 and to mold it together with the lower cassette part.

As can be seen from the drawings, the plate 1a has a hard foam plate part 1d which is located between the carbon fiber plate parts lc. The important feature of the plate 1a is that at least at one of its edges one carbon fiber plate part 1c or both carbon fiber plate parts 1c extend outwardly beyond the hard foam plate part ld, and the portion of the carbon fiber plate part or plate parts 1c which extends outwardly beyond the hard foam plate part 1d is bent upwardly or in other words toward the interior of the X-ray sheet film cassette. The thusly projecting web 1e increases the adhesive or welding surface. Thereby the connection produced between the lower cassette part or its frame 1 on the one hand and the web 1e or the plate 1a on the other hand can withstand the forces occurring during handling of the cassette.

In addition the web 1a increases the torsion strength of the X-ray sheet film cassette, without losing the advantages of the sandwich structure such as cost favorable manufacture, simple production of cambering and high transparency for X-ray radiation. Since the thermoplastically bonded carbon fiber plate parts 1c have the thickness of approximately only 0.3 mm, the wall thickness of the lower cassette part or its frame 1 is increased at the maximum only two times the thickness of the carbon fiber plate or in other words by approximately 0.6 mm. Thereby also the condition is fulfilled that the X-ray sheet film edge facing toward the hinge 3 comes as close as possible to the body of the patient.

As can be seen from FIG. 2a, two webs can be provided at opposite edges of the carbon fiber plate part 1c. The webs are identified as 1e and 1e' and extend outwardly beyond the hard foam plate part 1d at its opposite sides and are bent upwardly toward the interior of the X-ray sheet film cassette.

As can be seen from FIG. 7a the plates have a camber or bulging directed toward an interior of the cassette. Section I--I and II--II are shown in FIGS. 7b and 7c.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in an X-ray sheet film cassette, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.