DE2218989A1 - ROENTGEN FILM CASSETTE WITH A LOCK AND OPENING DEVICE SEPARATED FROM THE CASSETTE - Google Patents

Description

Re: "X-ray film cassette with a separate from the cassette Closing and opening device.

For the production of x-rays, double-sided xg are predominantly used emulsified flat films are used to shorten the exposure time and to reduce the exposure time After the radiation dose, the film is packed between two so-called reinforcing foils Foils must have intimate contact with the film over the entire surface so that they are sharp Pictures are created. Film and foils must be put together in a light-tight housing or cassette called, be accommodated.

As a rule, metal cassettes are used today, which are book-shaped to be opened and to be closed. The film and the Reinforcing foils pressed together with the help of a felt or rubber layer.

Through the special design of the lid and the closures, a light pressure of the foils can be achieved.

The disadvantages of these cassettes are: The initially elastic felt or The rubber layer soon flattens out and the specially shaped lids tire The pressure on the foils diminishes and the X-rays become less after prolonged use these cassettes are no longer so sharp.

In addition, such cartridges are thick and heavy in the aiming devices and cassette changing devices used in modern X-ray technology difficult to accelerate and decrease for fast series recordings due to their large mass the frame rates that can be achieved in such devices.

In addition to these rigid metal cassettes, there are also flexible ones made of black Opaque thin plastic known, in which the pressure is foils -Film is generated by internal vacuum.-The film-foil package is in a plastic bag plugged and pumped out and welded in a standard vacuum packaging machine.

The disadvantages of these cassettes are: They only have to be closed once Filling, evacuating and welding is time-consuming. The external dimensions are not defined because the edge is soft, the cassette is not dimensionally stable, It can be used with holders and grippers in target and exchange devices for quick series of exposures cannot be used in the devices that have been used to this day.

The disadvantages of the types of cassette described above are achieved according to the invention by the X-ray film cassette described below with a separate one from the cassette Closing and opening device avoided.

The cassette consists of two main parts, the thin radiolucent Lid and the thicker base. The parts can be made of light metal or plastic be manufactured.-Both parts have a reinforced edge, which is so with circumferential Grooves or grooves are provided so that the edges fit into one another. Rine or several the grooves are provided with a sealing material (e.g. rubber, soft PVC etc.). The cavity between the top and bottom is just high enough for the film-foil package Has space.

Feathers are attached to the edge between the lid and the bottom have the task of pushing the lid and bottom apart when inside and outside The air pressure inside the cassette is the same, but there is still pressure inside the cassette if the air is very diluted and the outside air pressure is normal, then the lids and Soil strongly compressed.-Since the sealing edge prevents the penetration of air the cassette is closed. Thanks to the elasticity of the thin cassette lid and of the sealing material becomes an ideal contact between the iqlm and the reinforcement foils achieved.

The procedure of closing and opening the cassette will be like is described as follows: The cassette loaded with the film is placed in the closing and Opening device gebr2ent. This consists of a hinged chamber, from which the air comes with. Can be largely removed with the help of a pump, with the base and cover of the cassette are only loosely on top of each other, the air is also inside the cassette removed.-Once this has been done, the two cassette parts are mechanically Device, which is operated from outside the chamber, against the force of the inner one The springs are so tightly compressed that the interior of the cassette passes through the edge seal is completed.

Then air is let into the chamber again and then the mechanical pressing device solved. The air pressure takes over the task this device and the cassette remains locked.

After the X-ray has been taken, the cassette is returned to the chamber Air is pumped out and once the air dilution in the chamber comes close to that If the size of the inside of the cassette is as large as it is, those attached inside the cassette come Springs to the effect and the cassette parts detach from each other.-The chamber becomes now ventilated again and the film can be removed.

The invention is described below with reference to schematic drawings for one exemplary embodiment each for the cassette and the associated locking and opening device explained in more detail.

It shows the Fig. 1 The two cassette parts, the cover 1 and the Bottom 2 in a perspective view.-With 3 and 4 are the matching You can also recognize the leaf springs marked 5, which have the task of pressing the two cassette parts apart.

Fig.2 The sectional drawing of an essential part of the cassette on a larger scale, once in the closed and once in the open state.

95an again recognizes the cover 1 and the base 2, the surrounding ones Grooves (grooves) 3 and 4, partially filled with the sealing material 6. as well one can see the reinforcement foils 7 and 8 and the X-ray film 9 the Verstar-uagsfoiie 7 is attached to the lid, the reinforcing foil 8 to the bottom is also one of the compression springs 5, which keep the base and cover apart.

Fig. 3 The perspective view of the closing and opening device the cassette.

The table 12 can be seen with a circumferential seal 13 on which the chamber 14 can be placed airtight. The valve 16 is movable with a Hose connected to a vacuum pump (not shown).

Between the slightly open chamber 14 and the table 12 is the Inserted cassette 1-2 partially visible.

The compression of the cassette parts 1 and 2 takes place in this Embodiment with a spindle screw lo.

4 shows a sectional view of the closing and opening device in the closed position Condition with inserted cassette 1-2.

One recognizes the table 12, the chamber 14 and in between the Seal 13.-The pressure plate 11 can lo on the cassette by means of the spindle screw be pressed. Valve 16 connects the chamber with the vacuum pump, valve 17 with the outside air.

3 and 4 will be used to close and open the cassette again Briefly described: Closing: Bring the cassette parts with the inserted film into the chamber open valve 16 evacuate chamber.

Using the spindle screw lo and pressure plate 11, the cassette parts 1-2 compress. Close valve 16, with valve 17 again air into the chamber - Turn back the spindle - Remove the locked cassette.

Open: bring the cassette into the chamber, evacuate the chamber with valve 16, as soon as possible If there is sufficient negative pressure, the cassette jumps open. Valve 16 is closed. By opening valve 17, air is let into the chamber. The film can now be removed will.

Claims (7)

Claims. Ilgrontgen film cassette characterized in that the base and cover without mechanical lock only by the; atmospheric pressure held together and remain in this state because there is a negative pressure inside the cassette prevails. 2. X-ray film cassette according to claim 1, in which the seal between cover and base by circumferential grooves or grooves, some of which with filled with an elastic material is achieved. 3. An x-ray film cassette according to claim 1, wherein the seal between lid and base due to the elastic properties of the edge material itself is achieved. 4. X-ray film cassette according to claim 1, characterized in that springs are attached between the top and bottom, which push the two parts apart as soon as The air pressure inside the cassette is almost the same as outside. 5. X-ray film cassette according to claim l, wherein the between lid and bottom-acting springs are attached in such a way that a lateral extension of the exposed film is possible with a mechanical gripper a new film can then be done by a mechanism. 6.Zur X-ray film cassette according to claim 1 belonging closing and opening device, characterized characterized in that it consists of an evacuable chamber in which the cassette parts cover and soil can be pressed together by acting from the outside. 7. Closing and opening device according to claim 6, characterized in that the mechanical pressure on the cassette parts from outside the chamber is accomplished, too can be done pneumatically or hydraulically.