DEVICE FOR RELEASING A FILM SHEET ADHERING TO THE INNER SURFACE OF THE UPPER CASSETTE PORTION OF AN X-RAY FILM CASSETTE

Abstract: In a device for releasing a film sheet (67) adhering to the inner side of the film-sheet support (19i) of the upper cassette portion (19c) of an X-ray film cassette (19) when said upper cassette portion (19c) is pivoted to its open position, a linkage-type multiple-lever arrangement (60, 61, 62) is hinged to a bar (10) adapted for aligning and positioning the X-ray film cassette (19). The last member (62) of said arrangement carries an air nozzle (70) as well as a pin (62a) and extends into the path of movement of the pivotable upper cassette portion (19c). When the upper cassette portion (19c) is pivoted to its open position, its end face (19h) slides along pin (62a) until the upper cassette portion (19c) rests on the last member (62). During further pivotal movement to the open position, the multiple-lever arrangement (60, 61, 62) is pivoted along and held by means of pin (62a) at the end surface (19h) of the upper cassette portion (19c). As a result, the air nozzle (70) is in its functional position at any opening angle of the pivotable upper cassette portion (19c). The air jet for releasing the film sheet (67) is directed approximately tangentially past the front edge (67a) of the film sheet (67) adhering to the inner surface of the film-sheet support (19i) of the upper cassette portion (19c).

Description: Device for Releasing a Film Sheet Adhering to the Inner Surface of the Upper Cassette Portion of an X-Ray Film Cassette The invention relates to a device for releasing a film sheet which adheres to the inner surface of the upper cassette portion of an X-ray film cassette when said upper cassette portion is pivoted to its open position, with the aid of air blown between the film sheet and the inner surface of the upper cassette por¬ tion. A film-sheet releasing device of this type is known (DE-OS 30 00 760) . The known device is associated with a slider provided in a cassette unloading and reloading apparatus for aligning and positioning an X-ray film cassette in the cassette unloading and reloading station of the apparatus. The slider is located later¬ ally above a transport belt by means of which an X-ray film cas¬ sette is transported from an input point up to a final abutment in the unloading and reloading station. If an X-ray film cassette is present in the unloading and reloading station, it is brought into contact with a stationary abutment ledge opposite to the slider when said slider moves laterally towards the X-ray film cassette. The film-sheet releasing device consists of a number of probes in the form of blast tubes which are arranged in the slider and extended pneumatically in the direction of the X-ray film cassette after the upper cassette portion has been slightly pivoted to its open position starting from the cassette side facing the slider. The blast tubes are moved below the marginal area of the slightly open upper cassette portion such that the blast air emitted by them can be distributed between the lower side of the upper cassette portion and a film sheet partially ad¬ hering to said lower side so that when the upper cassette portion is fully opened, the film sheet is not carried along but rests in the lower cassette portion. The probes are distributed at regular intervals across the length of the slider. Its number is determined by the length of an X-ray film cassette of maximum size. Owing to the great number of probes each of which is associated with a pneumatically controlled device consisting of a pressure cylinder and a piston guided therein and provided with the probe, the film-sheet releasing device as a whole is very expensive and complicated. It is the object of the invention to provide an inexpensive film-sheet releasing device of simple construction which operates reliably and precisely and which requires only one single air nozzle for releasing a film sheet from the upper cassette portion of X-ray film cassettes of various sizes. In accordance with the invention this object is attained in that linkage-type multiple-lever arrangement is hinged to a bar adapte for aligning and positioning X-ray film cassettes of different sizes, the last member of said multiple-lever arrangement extend¬ ing into the path of movement of the upper cassette portion of th X-ray film casssettes when said upper portion is pivoted to its open position, and being engaged and held by said upper cassette portion, in that the multiple-lever arrangement can be pivoted along when the upper cassette portion is pivoted to its open posi tion and in that the last member supports an air nozzle whose air jet is directed approximately tangentially past the front edge of a film sheet, seen in the input direction of the cassette, for re leasing such film sheet if adhering to the inner surface of the film-sheet support of the other cassette portion. According to a useful modification a linkage-type multiple-lever arrangement is hinged to at least one of two parallely guided bars movable towards and away from each other respectively for positioning the X-ray film cassette. The invention will now be described in further detail with reference to an embodiment illustrated in the drawings in which: Fig. shows a plan view of a cassette-positioning devic consisting of two parallely guided bars which are movable towards and away from each other respectively; Fig. shows a plan view of part of the positioning devi according to Fig. 1 with a film-sheet releasing device hinged to each bar; Fig. shows a sectional view along line II-II of Fig. 2, illustrating the film-sheet releasing device in various functional positions of the pivotable uppe cassette portion in an X-ray film cassette of smal size; Fig. shows a sectional view along line II-II in Fig. 2, illustrating the film-sheet releasing device in various functional positions of the pivotable uppe cassette portion in an X-ray film cassette of larg size; and Fig. shows a sectional view along line IV-IV in Fig. 4 illustrating 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 cassettes with unexposed film sheets, a device for positioning the X-ray film cassettes is provided in the area of the unloading and re¬ loading station. This positioning device comprises two parallely guided bars 10 and 12 which are movable towards and away from each other respectively and are moved by means of 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 around two shafts 14 one of which is driven. As can be seen in particular from Figs. 1 and 5 the bars 10 and 12 are mounted by means of scews 17 to angle plates 11 and 13. Each angle plate 11 and 13 respectively is shiftably mounted by means of a bushing 11a and 13a respectively on a guide shaft 16 ήeld between two mounting angles If of the apparatus. At the ends of the bars 10 and 12 extending into the interior of the appara¬ tus, 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 a partition wall la of the apparatus. The numeral le denotes a cassette-abutment ramp situated on the partition wall and the numeral Id two cassette abutments mounted to said partition wall. The bars 10 and 12 are operated by means of a symmetric lever ar¬ rangement situated between said bars and consisting of a two-arm lever 6 centrally mounted for rotation 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 supporting the bars 10 and 12. The numeral 2 denotes a drive motor screwed to a holding angle le provided on the apparatus. The free end 4a of a portion 4 of a rod consisting of two portions 4 and 5 movable relative to each other is hinged to a crank disk 2a seated on the motor shaft and rotatable to and fro in the direction of the arrows "A" and "B" by the motor. The other free end 5a of portion 5 of the rod di¬ rectly engages the hinge between lever 6 and the lever arm 8 pointing towards the left. In the area of each free end of the two bars 10 and 12 extending into the interior of the apparatus, a hold-down lever 20 and 21 is mounted which can be pivoted into and out of the transport path of the X-ray film cassette. X-ray film cassettes of various sizes are used. In the case of the embodiment, only an X-ray film cassette 19 of minimum size and an X-ray film cassette 190 of maximum size are shown. When an X-ray film cassette 19 and 190 respectively is entered into the input slot of the apparatus with the opening front edge of the upper cassette portion 19c and 190c respectively, where it opens, and is transported from the input point to the unloading and re- loading station, the motor 2 is switched on via switch means not illustrated in detail as soon as the front side of the cassette makes contact with one of the abutments Id, the motor operating the symmetric lever arrangement 6, 7 and 8 by means of the crank disk 2a rotatating in the direction "A" and the rod hinged to it, while the bars 10 and 12 are being moved towards each other from the initial position shown in dash-dotted lines in Fig. 1 until they make contact with the cassette side walls so that the X-ray film cassette is aligned and exactly positioned. A multiple-lever arrangement 60, 61 and 62, whose last member 62 carries in air nozzle 70 as will be described in detail further below, is hinged to at least one of the two bars. In the embodiment the multiple-lever arrangement 60, 61 and 62 is provided on both bars 10 and 12 (Fig. 2) . For this purpose, a bushing 66 is riveted to each of the angle plates 11 and 13 sup¬ porting the bars 10 and 12 (Fig. 5) . Pins 65 are mounted for rota¬ tion in the bushings 65. On each of the pins 65, a vertically ex¬ tending first lever arm 60 is arranged which projects through a recess 10c and 12c of each bar 10 and 12. A second lever arm 61 held by the force of a tension spring 54 against an abutment 60a and aligned with respect to the longitudinal direction of the opening front edge of the upper cassette portion 19c and 190c re¬ spectively is hinged to the free end 60b of each lever arm 60 (Figs. 3 and 4) . The last member 62, which extends into the path of movement of the pivotable upper cassette portion 19c and 190c respectively when the bars 10 and 12 rest against the side walls of the cassette, is hinged to the free end 61b of the second lever arm. 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 loosely on support means arranged on the two bars 10 and 12. A first angle portion lOd and 12d respective¬ ly provided with a support surface lOf and 12f respectively ser¬ ves as a support means for the second lever arm 61 and a second angle portion lOg and 12g respectively provided with a support surface lOh and 12h respectively (Fig. 3) serves as a support means for the last member 62. Each of the first angle portions lOd and 12d comprises an upwardly extending, inclined guide sheet lOe and 12e cooperating with a sensing pin 27 provided on the second lever arm 61 such that the multiple-lever arrangements assume a predefined initial position with respect to the front end face 19h and 190h respectively of the upper cassette portion 19c and 190c respectively. If the upper cassette portion 19c and 190c respectively of the X-ray film cassette 19 and 190 respectively, which is centered in its functional position in the unloading and reloading station by means of the bars 10 and 12, is pivoted by means not illustrated to the position shown in dash-dotted lines in Fig. 3 and 4 re¬ spectively . - the front end side 19h and 190h respectively of the upper cassette portion 19c and 190c respectively slides after a small distance along pin 62a until the upper cassette portion 19c and 190c respectively contacts the lower surface of the last mem¬ ber 62 which comes to rest against the upper cassette portion 19c and 190c respectively. When the upper cassette portion is further pivoted to its open position, the multiple-lever arrangements 60, 61 and 62 are also rotated about pin 55. During this operation the sensing pin 27 located on the second lever arm 61 leaves the guide sheet lOe and 12e respectively of the supporting angle lOd and 12d respectively so that the multiple-lever arrangements are only held by means of pin 62a on the end face 19h and 190h re¬ spectively of the open upper cassette portion 19c and 190c re¬ spectively. As shown in Fig. 3, the air nozzle 70 in the form of a blast tube is vertically shiftablε and horizontally rotatable in a holder 62b riveted to the last member 52. Its end piece is bent off in the direction towards the end face 19h and 190h respectively of the upper cassette portion 19c and 190c respectively. The bending angle "σ" is 5 to 50 degrees. As can be seen from Fig. 2, the end piece of air nozzle 70 is also inclined in the horizontal direc¬ tion by an angle ,r β" of about 20 to Q degrees with respect to the input direction of the X-ray film, cassette 19. While the upper cassette portion 19c and 190c is being pivoted into the position shown in dash-dotted lines, air is blown through the air nozzle 70 for a period of about 0.3 to 0.5 se¬ conds. By shifting the air nozzle 70 in the vertical direction, a position is defined in which its bent-off portion is aligned with respect to the support plane of the film sheet 67 and 68 respec¬ tively such that an air jet emitted is directed approximately tangentially past the front edge 67a and 68a respectively of a film sheet 67 and 58 respectively still adhering to the inner surface of the film-sheet support 19i of the upper cassette por¬ tion 19c and 190c respectively. Due to a difference in the pressure of the air at rest in the area above the film-sheet front edge 57a and 68a respectively projecting at the film-sheet support 19i and the air moved at high speed, which is caused by the air jet, touches the front edge 67a and 68a respectively of the film sheet and continues to f.low below the film sheet 57 and 68 respectively, a directional force is obtained which acts on the upper side of the projecting film sheet 67 and 68 respectively in the downward direction so that the front marginal area of the film sheet 67 and 68 respec¬ tively is separated in the downward direction. At that moment, part of the substantially slower air stream which surrounds the sharply directed air jet can reach the space between the film sheet 67 and 68 respectively and the film-sheet support 19i and build up an air cushion so that the film sheet 67 and 68 respec- I tively is rapidly and readily released from the film-sheet suppor 19i of the open upper cassette portion 19c and 190c respectively and drops back into the lower cassette portion 19a and 190a re¬ spectively. Subsequently the exposed film sheet is withdrawn from the lower cassette portion and transported into a development station whilst an unεxposed new film sheet is transported into the lower cassette portion. After the upper cassette portion has been pivoted to its closed position, the X-ray film cassette is removed from the apparatus. As shown in Fig. 3 the hinge 19k of the pivotable upper cassette portion 19c of an X-ray film cassette 19 of small size is located in the area of the pin 65 of the support for the multiple-lever arrangement. Owing to the short length of the upper cassette por¬ tion 19c, the spring-biased second lever arm 61, which is hinged to the upright first lever arm 50, rests on the abutment 50a of the first lever arm 60 when the upper cassette portion is in its open position. The multiple-lever arrangement 60, 61 and 62 is only pivoted along about the pin 65 in that the upright lever arm 60 pivots rεarwardly corresponding to the opening angle of the upper cassette portion 19c. Fig. 4 shows that the hinge (not illustrated) of the pivotable upper cassette portion 190c of an X-ray film cassette 190 of lar¬ ge size is far outside the area of the pin 65. Owing to the great length of the upper cassette portion 190c, the second lever arm 61 hinged to the upright first lever arm 60 is pivoted away from the abutment 60a of the first lever arm 60 in opposition to the force of tension spring 64 when the upper cassette portion is in its open position so that the pivotal movement of the multiple- lever arrangement takes place substantially about the hinge of the second lever arm 51 and the upright first lever 60. The upright first lever arm 60 only carries out a slightly rearwardl directed compensating pivotal movement about pin 65. Due to the linkage-type design of the multiple lever arrangement 60, 61 and 62 it is ensured that said arrangement always contacts with its last member the pivotable upper cassette portions of X-ray films of various sizes and is held at the end faces of the upper cassette portions and pivoted along when said upper cas¬ sette portions are pivoted to their open positions. As a result, the air nozzle 70 is in its functional position at any opening angle of the upper cassette portions pivoting to their opening positions.

Claims: - 9 - Patent Claims Device for releasing a film sheet, which adheres to the inne surface of the upper cassette portion of an X-ray film cas¬ sette when said upper cassette portion is pivoted to its ope position, with the aid of air blown between the film sheet and the inner surface of the upper cassette portion, c h a r a t e r i z e d in that a linkage-type multiple- lever arrangement (50, 61, 62) is hinged to a bar adapted fo aligning and positioning X-ray film cassettes (19, 190) of different sizes, the last member (62) of said multiple-lever arrangement extending into the path of movement of the upper cassette portion (19c, 190c) of the X-ray film cassettes (19, 190) when said upper portion is pivoted to its open position, and being engaged and held by said upper cassette portion, in that the multiple-lever arrangement {60, 61, 62) can be pivo¬ ted along when the upper cassette portion (19c, 190c) is pivoted to its open position and in that the last member (62) supports an air nozzle (70) whose air jet is directed approx¬ imately tangentially past the front edge (67a, 68a) of a film sheet (67, 68) , seen in the input direction of the cassette, for releasing such film sheet (67, 58) if adhering to the inner surface of the film-sheet support (19i) of the upper cassette portion (19c, 190c) . Device according to claim 1, characterized in that at least one of two parallely guided bars (10, 12) movable towards and away from each other respectively is hinged to a linkage-type multiple-lever arrangement (60, 61, 52) for accurately posi¬ tioning the X-ray film cassette (19, 190) . 3. Device according to claims 1 and 2, characterized in that the air nozzle (70) forms an angle "α" of 5 to 15 degrees verti¬ cally to the plane of the film-sheet support and an angle "β" of 20 to 40 degrees horizontally to the direction of input of a cassette. 4. Device according to claim 1 or 2 , characterized in that the multiple-lever arrangement comprises a first lever arm (60) hinged to each bar (10, 12) and extending vertically upward¬ ly, said lever arm being hingedly connected with a second lever arm (61) which is held by means of spring force against an abutment (60a) of the first lever ar (60) and aligned with respect to the longitudinal direction of the opening front edge of the upper cassette portion (19c, 190c) . 5. Device according to claims 1 or 2 and 4, characterized in that the last member (62) supporting the air nozzle (70) is hinged to the free end (61b) of the second lever arm (51) said last member carrying, adjacent to the air nozzle (70) , a pin (62a) which contacts the end face (19h, 190h) of the pivotable upper cassette portion (19c, 190c) . 5. Device according to claims 4 and 5, characterized in that the second lever arm (61) and the last member (62) rest loosely on support means arranged on the bars (10, 12) and designed as angular portions (lOd, 12d and lOg, 12g) . 7. Device according to claim 6, characterized in that the angular portions (10d, 12d and lOg, 12g) are provided with support surfaces (lOf, 12f and lOg, 12g) . 8. Device according to one or several of claims 1 to 7, charac¬ terized in that the angular portion (lOd, 12d) associated with the second lever arm (61) comprises an upwardly inclined guide sheet (lOe, 12e) cooperating with a sensing pin (27) arranged on the second lever arm (51) such that the multiple-lever arrangement (60, 61, 52) assumes a predefined initial position with respect to the front end face (19h, 190h) of the upper cassette portion (19c, 190c) .

Inventors: KILLGUSS HEINRICH, MIRLIEB BERND, QUANZ GERHARD, KILLGUSS, HEINRICH, MIRLIEB, BERND, QUANZ, GERHARD
Applicants: EASTMAN KODAK CO, KODAK AG, EASTMAN KODAK COMPANY, KODAK AKTIENGESELLSCHAFT
Application year: 1988
Main classification: G03B42
IPC codes: B65H3, G03B42