CASSETTE UNLOADING AND RELOADING APPARATUS

Abstract: An apparatus for unloading and exposed film sheet from an X-ray film cassette (19) and for reloading said cassette with an unexposed film sheet is provided with two parallely guided bars (10 and 12) movable towards, and away from each other respectively for positioning the X-ray film cassette (19). In order to make possible a properly functioning operation as regards the monitoring of the presence of a film sheet and the prompt availability of a film sheet present for the purpose of its removal from the X-ray film cassette, means are provided which are arranged in the form of assembly groups on each bar (10, 12). These means comprise a cassette hold-down lever (20, 21) mounted on each bar (10, 12), a pair of infrared-light sensors (30, 31) arranged on each bar and a pair of deflecting mirrors (42, 43) associated with said pair of sensors and adapted to transmit the infrared-light radiation into the upper and lower cassette portions when the upper cassette portion is pivoted to its open position, as well as a multiple-lever arrangement (60, 61, 62) also hinged to each bar (10, 12) and cooperating with the pivotable upper cassette portion, said arrangement comprising an air nozzle (70) whose air jet is directed past the front edge of the film sheet for promptly releasing a film sheet adhering to the upper cassette portion.

Description: Cassette Unloading and Reloading Apparatus The invention relates to a cassette unloading and reloading apparatus with two parallely guided bars which are movable towards each other and away from each other respectively for accurately positioning an X-ray film cassette and with means for holding down said cassette and for detecting the presence or absence of a film sheet by means of in¬ frared light as well as a means for releasing a film sheet adhering to the upper cassette portion. An apparatus is known (DE-OS 33 06 720) in which an X-ray film cassette is positioned between two parallely guided bars pulled together by a tension spring and is transported by means of motor-driven rollers on a receiving plate towards an end abutment in a cassette unloading and reloading station. The bars have vertically shiftable claws at their free ends located in the area of the end abutment, said claws serving to open the locking means of the upper cassette portion, when the re¬ ceiving plate and thus the X-ray film cassette are moved to an in¬ clined position, as well as to hold down the lower cassette portion on said inclined receiving p ' late. An infrared-light sensor with an associated light-receiving element is arranged above the front area of the X-ray film cassette when said cassette is in its functional position, the infrared light rays of that sensor sensing a point on the inner surface of the lower cassette portion when the upper cassette portion is pivoted to its open posi¬ tion in order to ascertain whether a film sheet is present or not. If there is no film sheet present, the X-ray film cassette is fed out of the apparatus in its open condition. This known apparatus is disadvantageous in that when the upper cassette portion is pivoted to its open position, the film sheet adheres to the inner surface of the upper cassette portion owing to static charges of the film sheet resting planely on the inner surface of the plastic lining of the upper cassette portion. The film sheet is only released after a period of time and then drops back into the lower cassette portion. If during the adherence of the film sheet to the upper cas¬ sette portion in its open position, the lower cassette portion is sen¬ sed by infrared light, no film sheet is detected in the lower cassette portion so that the X— ray film cassette in its open position along with the film sheet adhering to the upper cassette portion may be er¬ roneously fed out. If several sensing operations were performed at in¬ tervals, with the last one ascertaining that a film sheet was present which had been released from the upper cassette portion in the mean¬ time and dropped back into the lower cassette portion, this operation would take much too long. If a film sheet of small size is erroneously loaded in an X-ray film cassette of large size the film sheet will be detected even if only one single point in the lower cassette portion is sensed. However the detection does not reveal whether it is of a size suitable for the X.— ray film cassette- Finally, the infrared— light sensor is arranged at a great distance above the X-ray film cassette. This remote arrangement of the infrared- light sensor is necessary because the sensor would otherwise be con¬ tacted, and damaged by the upper cassette portion when said portion is pivoted to its open position. It is the object of the invention to develop and improve an apparatus of the above .type such that the cassette is held down reliably when the- upper cassette portion is pivoted to its open position, the pre¬ sence or absence of a film sheet is readily detected, and a film sheet is. promptly made available for transport out of the X-ray film cassette and: that the necessary means are accommodated in a space-saving manner in the cassette unloading and reloading station. In accordance with the invention this object is attained in that the means serving for holding down the cassette and for infrared-light sensing of the open X-ray film cassette as well as for releasing the film sheet are arranged in the form of an assembly group on each bar. In more detail the invention is such that the means consist of a hold- down lever mounted to each bar and pivotable into and out of the trans¬ port path of the X-ray film cassette, a pair of infrared-light sensors arranged on each bar and a pair of deflecting mirrors associated with said pair for transmitting infrared light rays into the upper and lower cassette portions as well as a multiple-lever arrangement hinged to each bar and provided with an air nozzle. Due to the fact that these means are arranged on the bars, they are always brought into engagement with the X-ray film cassettes at suit¬ able points which are always the same irrespective of the format of the X-ray film cassette. Thus a number of further devices which are necessary to pivot the upper cassette portion to its open position and to transport a film sheet out of the X-ray film cassette into a film developing station are not interfered with by the means arranged on the bars and can be accommodated in the cassette unloading and reload¬ ing station without their movement being restricted. In the following, the invention will be explained in further detail with reference to an embodiment illustrated in the drawings in which Fig. 1 is a plan view of a cassette-positioning device consisting of two parallely guided bars movable towards and away from each other respectively, Fig. 2 is a plan view of part of the positioning device according to Fig. 1 including the devices according to the invention, with the upper cassette portion pivoted to its closed position, Fig. 3 is a plan view of part of the positioning device according to Figs. 1 and 2 including the devices according to the invention, with the upper cassette portion pivoted to its open position, Fig. 4 is a sectional view along line II— II of part of the positioning device according to Fig. 3, with an infrared-light sensing device arranged on one bar, Fig. 5 is a sectional view ' along line III— III of part of the positioning device according to Fig. 3, with a film-sheet releasing device arranged on one bar, and Fig. 6 is a sectional view along line IV -IV of part of the positioning device according to Fig. 3, with an infrared-light sensing device arranged on one bar and with part of the film sheet releasing device. In an apparatus 1 for unloading exposed film sheets from X-ray film cassettes of different sizes and reloading the same cassettes with unexposed film sheets, a device for positioning the X-ray film casset¬ tes is provided in the area of the unloading and reloading station. This positioning device comprises two parallely guided bars 10 and 12 movable towards and away from each other respectively and moved fay a transport belt 15 transporting an X-ray film cassette 19 from an input point to the unloading and reloading station. The transport belt 15 is placed about two shafts 14 one of which is driven. As shown in particular in Figs. 1 and 6, the bars 10 and 12 are fixed to angle plates 11 and 13 by means of screws 17. Each angle plate 11 and 13 respectively is shiftably mounted by means of a guide sleeve 11a and 13a respectively on a guide shaft 16 held between two mounting angles If provided on the apparatus. At the end of the bars 10 and 12 extending into the interior of the apparatus, guide grooves 10a and 12a are provided by means of which the bars 10 and 12 are additionally guided for sliding movement on guide rails lb arranged on an inter¬ mediate wall la of the apparatus. The numeral le denotes a cassette abutment ramp situated on the intermediate wall La and the numeral Id two cassette abutments fixed to said intermediate wall. For actuating the two bars 10 and 12, a symmetrical lever arrangement is provided which is located between said bars and consists of a two arm lever 6 centrally mounted for pivotal movement about a stationary pin 6c. A first lever arm 7 pointing to the right is hinged to one free lever end 6a and a second lever arm 8 pointing to the left is hinged to the other free lever end 6b. The free ends 7a and 8a of the two lever arms 7 and 8 are hinged to the angle plates 11 and 13 sup¬ porting the bars 10 and 12. A drive motor 2 is screwed to a mounting angle lc provided on the ap¬ paratus. On a crank disk 2a seated on the motor shaft and movable to and. fro by the motor in the directions "A" and "B", the free end 4a of a portion 4 of a rod is hinged which consists of two portions 4 and 5 movable relative to each other. The other free end 5a of portion 5 of the rod engages directly the hinge between lever 6 and lever arm 8 pointing to the left. In the area of each of the two ends of the two bars 10 and 12, which extend into the interior of the device, a hold-down lever 20 and 21 is mounted which can be pivoted into, and out of the transport path of an X-ray film cassette (Figs. 2 and 3). Each hold-down lever comprises a control arm 20a and 21a. These arms extend upwardly (Fig. 5) and are slightly inclined outwardly in the direction towards the bars 10 and 12 so that they form inclined control surfaces facing the side walls of the upper cassette portion 19c. Moreover, a hold-down nose 20b and 21b is provided on each hold-down lever 20 and 21. Both hold-down levers 20 and 21 are biased by a tension spring 23 in the direction of their inward pivotal movement. The hold-down levers rest with their inner surfaces 20d and 2 Id against bent-off portions 10b and 12b of the bars 10 and 12. X-ray film cassettes of various sizes are used. In the case of the em¬ bodiment, only an X-ray film cassette 19 of small size is illustrated. If such an X-ray film cassette 19 is introduced with the opening front edge of the upper cassette portion 19c into the input slot of the appa¬ ratus and transported from the input point to the unloading and reload¬ ing station, the motor 2 is switched on by switch means not illustrated in detail when the front side of the cassette contacts one of the abut¬ ments Id, said motor actuating by means of crank disk 2a rotating in the direction "A" and the rod hinged thereto the symmetrical lever ar¬ rangement 6, 7 and 8, with the bars 10 and 12 being moved from their initial position shown in dash-dotted lines in Fig. 1 towards each other to assume a position in which they rest against the side walls of the cassette so that the X-ray film cassette is aligned and exactly po¬ sitioned. Directly before the bars 10 and 12 contact the cassette side walls, the control arms 20a and 21a of the hold-down levers 20 and 21 make contact with the side walls of the upper cassette portion 19c. Each of the hold- down levers 20 and 21 is pivoted back to the position illustrated in Fig. 2. When the upper cassette portion 19c is pivoted to its open po- sition by means not illustrated, the hold-down levers 20 and 21 are brought into engagement with the lower cassette portion 19a via their inclined control arms 20a and 21a resting against the side walls 19d and 19e of the upper cassette portion 19c. In this position of the two hold-down levers, the inner surfaces 20d and 21d once again rest against the bent-off portions 10b and 12b of the bars 10 and 12, and the hold— down noses 20b and 21b are in a position above the stepped edge 19b of the lower cassette portion 19a (Fig. 3). After exposed film sheets have been unloaded from the X-ray film cas¬ sette and the cassette has been reloaded with unexposed film sheets, the side walls of the upper cassette portio 19c slide along the in¬ clined control arms 20a and 21a when said portion is closed, the in¬ clined position of the control arms causing the hold-down levers 20 and 21 to become disengaged from the lower cassette portion 19a. According to a further useful modification of the aparatus, a multiple- lever arrangement 60, 61 and 62 is hingedly connected to the two bars 10 and 12, the last-mentioned member 62 of said arrangement carrying an air nozzle 70 as . will . be described in detail further below (Figs. 2 and 5). For this purpose a a bushing 66 each is riveted to the angle plates 11 and 13 supporting the bars 10 and 12 (Fig. 6). Pins 65 are rotatably mounted in the bushing 66. Each of the pins 65 is provided with a ver¬ tically- upright first lever arm 60 extending through a recess 10c and 12c in each bar 10 and 12. A second lever arm 61 is hingedly connected to the free end 60b of each lever arm 60 (Fig. 5), said second lever arm being held in contact with an abutment 60a by the force of a ten¬ sion spring 64 and extending approximately at right angles to the di¬ rection of the opening front edge of the upper cassette portion 19c. The last member 62 of the lever arrangement is hinged to the free end 6 id of lever arm 61 and extends into the path of movement of the pivot¬ able upper cassette portion 19c when the bars 10 and 12 rest against the side walls of the cassette. Member 62 carries the air nozzle 70 and a pin 62a riveted adjacent to said nozzle. The second lever arm 61 and the last member 62 of each multiple-lever arrangement rest losely on support means arranged on the two bars 10 and 12. The support means for the second lever arm 61 consist of a first angle portion lOd and 12d respectively provided with a support surface lOf and 12f respectively, and the support means for the last member 62 consist of a second angle portion lOg and 12g respectively provided with a support surface lOh and 12h respectively (Figs. 2 and 5). The first angle portions lOd and 12d each comprise a sheet-metal guide lOe and 12e extending upwardly in an inclined position and co¬ operating with the sensing pin 27 arranged on the second lever arm 61 such that the multiple-lever arrangements assume a predefined initial position relative to the front end surface 19h of the upper cassette portion 19c. When the upper cassette portion 19c of the X-ray film cassette 19, which is centered in its functional position in the unloading and re¬ loading station by means of the bars 10 and 12, is pivoted to its open position shown in dash-dotted lines in Fig. 5 by means not illustrated, the front end surface 19h of the upper cassette portion 19c slides after only a small distance along pin 62a until the upper cassette por¬ tion 19c abuts against the lower surface of the last member 62 which makes contact with the upper cassette portion 19c. When the upper cas¬ sette portion is further pivoted to its open position, the multiple- lever arrangements 60, 61 and 62 are also pivoted by rotating about pin 65. During this operation sensing pin 27 located on the second lever arm 61 moves away from the sheet-metal guide lOe and 12e respectively of support angle lOd and 12d resepctively so that the multiple lever arrangements are only held by means of pin 62a on the end surface 19h of the upper cassette portion 19c pivoted to its open position. The air nozzle 70, which takes the form of a blast tube, is arranged as shown in Fig. 5 in a holder 62b riveted to the last member 62 so as to be shiftable in the vertical direction and rotatable in the horizontal direction. Its end piece is bent off in the direction towards the end surface 19h of the upper cassette portion 19c. The bending angle "α" is 5 to 15 degrees. As can be seen in Fig. 2, the end piece of the air nozzle 70 is also inclined in the horizontal by an amount "β" of about 20 to 40 degreees with respect to the direction in which the X-ray film cassette 19 is introduced. While the upper cassette portion 19c is being pivoted to its open posi¬ tion indicated in dash-dotted lines, air is blown through the nozzle 70 for a period of about 0.3 to 0.5 seconds. By shifting of the air nozzle 70 in the vertical direction, a position is defined in which the bent- off portion is aligned with respect to the support plane of the film sheet 67 such that an air jet is directed approximately tangentially past the front edge 67a of a film sheet 67 still adhering to the inner surface of the film— sheet support 19i of the upper cassette portion 19c. Due to a difference in the pressure of the air stagnant in the area above the film sheet's front edge 67a projecting from the film-sheet support 19i and the air moved at high speed as a result of the sharp air jet directed tangentially past the front edge 67a of the film sheet and continuing to flow below the film sheet 67, a directional force is obtained which acts downwardly on the upper side of the projecting film .sheet 67 so that the front edge section of film sheet 67 is separated downwardly. At that moment, part of the substantially slower air stream surrounding the sharply directed air jet can reach the space between film sheet 67 and film-sheet support 19i and build up an air pad so that film sheet 67 is promptly and readily released from the film-sheet support 19i of the open upper cassette portion 19c and drops back into the lower cassette portion 19a. Subsequently the exposed film sheet is withdrawn from the lower cassette portion and fed into a development station while a fresh, unexposed film sheet is fed into the lower cas¬ sette portion. After the upper cassette portion has been pivoted to its closed position, the X-ray film cassette is transported out of the ap¬ paratus. As shown in Fig. 5, hinge 19k of the pivotable upper cassette portion 19c of an X-ray film cassette 19 of small size is situated in the range •of pin 65 of the mounting of the multiple-lever arrangement. Owing to the small length of the upper cassette portion 19c, the spring-biased second lever arm 61 hinged to the upright first lever arm 60 rests against the abutment 60a of the first lever arm 60 when the upper cas¬ sette portion is pivoted to its open position. The multiple-lever ar¬ rangement 60, 61 and 62 is at the same time only pivoted about pin 65 in that the upright lever arm 60 is pivoted rearwardly by a distance corresponding to the opening angle of the upper cassette portion 19c. Due to its hinged connection the multiple-lever arrangement 60, 61 and 62 can always be brought into contact with the pivotable upper cassette portion with its last member 62, even in the case of upper cassette portions of X-ray film cassettes of different sizes, and is held at the end sides of the upper cassette portions, and pivoted along when such upper cassette portions are pivoted to their open positions. As a re¬ sult the air nozzle 70 is held in its functional position irrespective of the opening angle of the pivoted upper cassette portions. Finally infrared-light sensing devices with associated radiation de¬ flecting means are provided on each of the two bars 10 and 12. As shown in Figs. 3, 4 and 6, two mounting brackets 34 and 35 of dif¬ ferent heights are arranged on the angle plates 11 and 13 which sup¬ port the bars 10 and 12. An infrared-light sensor 30 and 31 with an associated light receiving element is screwed to each of these two mounting brackets 34 and 35. Another mounting bracket 46 is provided at the free ends of each of the two bars 10 and 12 which extend into the interior of the appa¬ ratus. Each of the mounting brackets 46 supports two mirrors 42 and 43 arranged above each other in the raypath of the two infrared-light sensors 30 and 31. The mirrors are inclined such that when the X-ray film cassette is pivoted to its open position, the rays 30a emitted by the upper two infrared light sensors 30 are directed via the upper two mirrors 42 into the lower cassette portion 19a and the rays 31a emit¬ ted by the lower two infrared-light sensors 31 are directed via the lower two mirrors 43 into the upper cassette portion 19c. In both the lower cassette portion 19a and the upper cassette portion 19c, two small reflecting pieces of foil 38, 39 and 40, 41 are arran¬ ged in the measuring range of the infrared-light sensors; said pieces of foil have higher reflecting power than a film sheet and the proper¬ ties of a triple-corner mirror. As soon as the upper cassette portion 19c has been pivoted to the open position shown in dash-dotted lines (Figs. 4 and 5), during which opera¬ tion both the cassette hold-down levers 20 and 21 are pivoted inward¬ ly, and the film sheet 67 still adhering to the open upper cassette portion 19c is pneumatically released - as will be described further below - the infrared-light sensors 30 and 31 are actuated to sense the lower and upper cassette portions 19a and 19c. If the film sheet 62 has dropped into the lower cassette portion 19a as desired, its pre¬ sence is signalized in response to the signal difference between the film sheets 62 covering the reflecting pieces of foil 38 and 39 in the lower cassette portion 19a and the uncovered pieces of foil 40 and 41 in the upper cassette portion 19c. If the film sheet has not been re¬ leased from the upper cassette portion 19c, the signal difference between the free uncovered pieces of foil 38 and 39 in the lower cas¬ sette portion 19a and the pieces of foil 40 and 41 still covered by the film sheet 62 in the upper cassette portion 19c indicates that the film sheet is not yet ready for transport in the lower cassette por¬ tion. If no film sheet is present in the X-ray film cassette, this is indi¬ cated by a uniform reflection signal of all four uncovered pieces of foil. If a film sheet of small size is erroneously loaded in an X-ray film cassette of large size, this film sheet can assume a position in the lower cassette portion in which either none of th,e two pieces of foil * 38 and 39 or only one piece of foil is covered. As a result of the space-saving arrangement of all devices on the bars 10 and 12 of the cassette-positioning device, these devices are always brought into engagement at the same point of an X-ray film cassette loaded in the unloading and reloading position independently of the size of the cassette. Moreover, the cassette hold-down device, which becomes operative when the upper cassette portion is pivoted to its open position, the pneu¬ matic film-sheet releasing device used, and the immediately following infrared-light sensing of the lower upper cassette portions ensure that all functions take place promptly, reliably and without any pro¬ blems at the beginning of the cassette unloading operation.

Claims: Patent Claims I. Cassette unloading and reloading apparatus with two parallely guided bars which can be moved towards, and away from each other respectively for accurately positioning an X-ray film cassette and with means for holding down said cassette and for detecting the presence or absence of a film sheet by means of infrared light as well as with means for releasing a film sheet adhering to the upper cassette portion, c h a r a c t e r i z e d in that the means (20, 21; 30, 31; 42, 43, 70) serving for holding down the cassette and for infrared-light sensing of the open X-ray film cassette as well as for releasing the film sheet are arranged in the form of assembly groups on each bar ( 10, 12). 2. Apparatus according to claim 1, characterized in that the means consist of a hold-down lever (20, 21) mounted to each bar (10, 12) and pivotable into and out of the transport path of the X-ray film cassette, a pair of infrared light sensors (30, 31) arranged on each bar (10, 12) and a pair of deflecting mirrors (42, 43) asso¬ ciated with said pair and serving for transmitting infrared-light rays (30a, 31a) into the upper and lower cassette portions ( 19a, 19c) as well as a multiple-lever arrangement (60, 61 , 62) hinged to each bar ( 10, 12) and provided with an air nozzle (70).

Inventors: BAUMANN KURT, KILLGUSS HEINRICH, MIRLIEB BERND, BAUMANN, KURT, KILLGUSS, HEINRICH, MIRLIEB, BERND
Applicants: EASTMAN KODAK CO, KODAK AG, EASTMAN KODAK COMPANY, KODAK AKTIENGESELLSCHAFT
Application year: 1988
Main classification: G03B42
IPC codes: G03B42