GB2100882A - Apparatus for unloading radiation-sensitive film from a container and for conveying the film to a developing machine - Google Patents

Abstract

At an unloading station 5, an X- ray film 22 is removed from a cassette 1 and is fed by rollers 6, 7 at a relatively high speed V1. Subsequently the film is fed to a developing machine 8 at a relatively low speed V2 by a pair of rollers 9, 10. The film is conveyed from the unloading station 5 to the developing machine 8 by means of a conveying system 11 comprising two pairs of rollers 12, 13 and 14, 15 which are driven in unison by a common variable speed drive 18. When a sensor 19 detects a leading end of the film 22 the rollers 12 to 15 are driven at a speed V1 which matches that of the rollers 6, 7, but are slowed to a speed V2 which matches that of the rollers 9, 10 when the sensor 19 detects the trailing end of the film. As illustrated, the system 11 can be arranged along a line between the unloading station 5 and the developing machine 8. Alternatively (Figure 2, not shown) it can be oriented at right-angles to and on one side of this line, with the drive (18') being reversed as well as having its speed changed when the sensor 19 detects the trailing end of the film. In this case, deflectors (23a, 23b) are provided to alter the direction of travel of the film appropriately. In a further embodiment (Figure 3, not shown) a selector device (25) can be provided to deflect the film from the unloading station 5 selectively to the conveying system 11 or to a film storage magazine (24). <IMAGE>

Description

SPECIFICATION Apparatus for unloading radiation-sensitive film from a container and for conveying the film to a developing machine This invention relates to apparatus for unloading radiation-sensitive film (such as X-ray film) from a container and for conveying the film to a developing machine.

One example of such apparatus is disclosed in European Patent Application No. 0 017 269 wherein, in order to enable the container to be unloaded as quickly as possible, a film storage magazine is provided into which the films unloaded from the container are fed at high speed.

A dispenser device is disposed on the opposite side of this magazine and dispenses the stored films to the developing machine in the order in which they were inserted in the magazine, this operation being performed at a speed which corresponds to that of the developing machine.

However, this apparatus is rather complex and expensive, and in many cases the number of X-ray photographs to be processed is not large enough to warrant its purchase. On the other hand, even in such a situation it is not desirable that operating personnel are delayed too long in or by the unloading of the films from the container.

It is an object of the present invention to obviate or mitigate this problem.

According to the present invention, there is provided apparatus for unloading radiationsensitive film from a container and for conveying the film to a developing machine, comprising an unloading station at which said container is opened and said film is extracted therefrom at a first, relatively high speed, a feeding station at which said film is fed to the developing machine at a second, relatively low speed, and a film conveying system for conveying said film from the unloading station to the feeding station, the conveying system including a drive which is operable at least at two different speeds such that said film can be conveyed selectively at speeds which are matched to said first and second speeds, respectively.

In this way, the film can be unloaded in a fast and gentle manner whilst dispensing with the provision of a storage magazine where this is undesirable. Thus, it is possible to achieve direct unloading of the film from the container and into the developing machine without intervening storage of the films, and moreover such unloading can be accomplished in a relatively short time.

The conveying system preferably also includes at least one pair of rollers which are driven by said drive, the rollers in each pair receiving the film therebetween to convey the latter. Where at least two such roller pairs are provided, they are advantageously driven at the same but changeable speed by a common drive.

Conveniently, the conveying system includes a sensor which detects leading and trailing ends of the film, and the speed of the drive is changed in response to such detection by the sensor. The sensor may tor example be in the form of a light barrier comprising a light source (such as an infra red light source) and a light-sensitive detector disposed on opposite sides of the film path.

In one embodiment of the invention the feeding station includes a pair of rollers which receive said film therebetween to feed the latter, and the conveying system is arranged along a line extending between the unloading and feeding stations, the distance between the sensor and the rollers at the feeding station being at least equal to the longest film to be conveyed.

In another embodiment, the drive is reversible such that the conveying system conveys the film from the unloading station in one direction and subsequently conveys the film to the feeding station in the opposite direction. In this case, the direction of the drive will be reversed in response to the said detection by the aforementioned sensor. In a preferred example of this embodiment, the film is extracted from the container at the unloading station generally in a first plane and is fed to the developing machine generally in a second plane, the first and second planes being generally mutually parallel, the conveying system conveys said film generally in a third plane which is oriented transversely to the first and second planes, and deflection means is provided to deflect said film from said first plane to said third plane and from said third plane to said second plane.

In a further embodiment of the invention, the apparatus is designed for use in equipment where a film storage magazine is needed due to very heavy workloads, and a facility is provided whereby a specific X-ray photograph can be preferentially processed. To this end, the apparatus comprises a film store in which said film can be stored prior to being fed to the developing machine, and a selector device which is operable to direct said film from the unloading station selectively to the conveying system and the film store.

The invention will now be further described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a schematic side view of a first embodiment of apparatus according to the present invention; Figure 2 is a schematic side view of a second embodiment of apparatus according to the present invention; and Figure 3 is a schematic side view of a third embodiment of apparatus according to the present invention.

Referring first to Figure 1, a cassette 1 or similar container containing a sheet 22 of X-ray film is received on a table 2 at an unloading station 5. A mechanism 3 having gripper elements opens the cassette 1 and the film sheet therein is extracted by means of a suitable device, such as a suction device 4. Both the mechanism 3 and the device 4 are well known per se, and accordingly they are only illustrated schematically and will not be described further. The device 4 then feeds the film 22 to a pair of rollers 6 and 7 which feed the film from the unloading station 5 at a relatively high speed V1. Subsequently, the film is received by a pair of rollers 9, 10 at a feeding station which feed the film to a developing machine 8 at a relatively low speed V2.

Between the unloading station 5 and the developing machine 8 there is provided a film conveying system 11, which comprises essentially two pairs of feed rollers 12,13 and 14,15 mounted in lateral supports 1 6 which are secured to a plinth base 17. One roller in each pair (for example the rollers 13 and 15) is driven by a variable speed drive 18, such that all four rollers rotate at the same but changeable speed. A sensor 1 9 is disposed between the rollers 6, 7 in the conveying system 11 and detects the passage of leading and trailing ends of the film 22, whereupon it operates a changeover switch 20 to alter the speed of the drive 1 8. The sensor 1 9 is in the form of a light barrier and comprises an infra red light source and a light-sensitive detector which are disposed on opposite sides of the film path, indicated by a broken line 21.All of the roller pairs6and7, 12 and 13, 14and 15,9 and 10are arranged so that the path 21 is planar.

Furthermore, the distance between the sensor 1 9 and the rollers 9 and 10 at the developing machine 8 is at least equal to the length of the largest film sheet likely to be extracted from the cassette 1.

The apparatus described above operates in the following manner. After the cassette 1 has been opened by the mechanism 3, a film sheet 22 is lifted out of the cassette by means of the suction device 4 and is fed between the rollers 6 and 7.

This transports the film 22 out of the cassette at the aforesaid relatively high speed V1. As soon as the film has left the cassette the latter may be removed or carried off to be re-loaded. As soon as the leading edge of the film 22 passes through the light barrier provided by the sensor 19, the latter actuates the changeover switch 20 to set the drive 1 8 so that it rotates the rollers 12 to 1 5 at a peripheral speed equal to V1. Thus, the roller pairs 12, 13 and 14, 1 5 are accelerated to the higher speed V1 and convey the film accordingly.

However, as soon as the trailing end of the film leaves the light barrier, the sensor 1 9 issues a further signal to the switch 20 which thereupon switches the drive 1 8 so that it rotates the rollers 12 to 15 at a peripheral speed equal to V2. At this speed, which corresponds to the feeding speed of the developing machine 8. the film is now conveyed further and is eventually fed into the intake rollers 9, 10 of the developing machine.

When dealing with films of large format, the requirement that the total length of the conveying system must equal or exceed the length of the film, may cause the overall size of the apparatus to be made relatively large. For this reason, the principle illustrated in Figure 1 can be modified to arrive at the arrangement depicted in Figure 2, which allows the distance between the unloading station 5 and the developing machine 8 to be substantially shortened. More particularly, the film conveying system 11 now extends substantially perpendicularly to a line connecting the exit gap of the unloading station 5 to the entrance gap of the developing machine 8, and is preceded by an adapter moulding 23 w hich comprises two integrally moulded deflector elements 23a and 23b.The first deflector element 23a deflects the path of the film through annroximately 900 and steers a moving film through the sensor 19 into the first pair of rollers 12, 13. In other respects, the conveying system 11 is constructed in the same manner as the system shown in Figure 1, except that it is rotated through 900 from its position in that figure. However, there is one important further difference, namely that when the drive (now referenced 1 8') is switched over by the changeover switch 20, it not only changes the speed of the rollers 12 to 1 5 but also reverses the direction of their rotation.This means that when the light sensor 1 9 is triggered by the leading edge of a film 22, the drive 1 8' operates to rotate the rollers 13 and 15 clockwise at the higher speed V1, but after the trailing edge of film 22 has passed the sensor 1 9 the rollers 13 and 1 5 are driven anticlockwise at the lower speed V2. This brings the film 22 back to the top of the conveying system 11 until it hits against the deflector element 23b which crosses its path, the deflector element then steering the film between the rollers 9, 10 at the developing machine 8.

A further embodiment of the invention is shown in Figure 3, which is particularly well suited for high performance systems. As already mentioned, it is customary in such systems to provide a film storage magazine (referenced 24) into which the films are delivered from the unloading device 5, collected and transferred on the other side of the developing machine. In order to avoid having to feed particularly urgent or important X-ray photographs into this magazine 24 so that they may be processed directly, a conveying system 11 of the type described above is provided in combination with the storage magazine 24.

More particularly, a selector device (launching a switch rail 25 which is adapted to pivot about an axis 26) is arranged at the output side of the rollers 6,7 at the unloading station 5. Behind the switch rail 25 is disposed a pair of feed rollers 29, 30 for feeding the film into the storage magazine 24. On the dispensing side of the magazine 24 there is provided a further pair of rollers 29, 30 and a separating device 31 which feeds the film sheet first entered into the magazine into the gap between the rollers 29, 30.

Adjacent the roller pair 29, 30 there is a guide element 32 which directs the film towards the roller pair 9, 10 at the developing machine 8. As can be seen to advantage in Figure 3 the storage magazine 24 is arranged on one side of the connecting line between the unloading station 5 and the developing machine 8, while the film conveying system 11 is arranged on the opposite side of this line.Since, due to the provision of the magazine 24, the distance between unloading station 5 and developing machine 8 may have to be made somewhat longer than in the embodiment of Figure 2, correspondingly extended deflector elements 23' (which may be interrupted by further roller pairs 33, 34 and 35, 36) are provided between rollers 6, 7 at the unloading station 5 and the rollers 12, 13 of the conveying system 11, as well as between the rollers 12, 13 and the rollers, 9, 10 at the developing machine 8.

When the switch rail 25 occupies the position illustrated in full lines, the films are fed at the rapid speed V1 via the roller pair 27, 28 into the magazine 24. From there the films are successively dispensed at the slower speed V2 via the roller pair 29, 30 along the guide element 32 and into the gap between the rollers 9, 10 at the developing machine 8. When the switch rail 25 is moved over to the position indicated in broken lines, a film is fed at the high speed V1 via the roller pair 33, 34 (which also rotates at speed V1) to the roller pair 12,13 and then proceeds as described above with reference to Figure 2. Upon reversal of the direction of the drive 1 8', the film is conducted along the deflector element 23' and is fed into the developing machine 8 via the rollers 35, 36 which rotate at the slower speed V2.

Although not specifically shown, the switch rail 25 is operatively coupled to the separating device 31 by means which ensure that the dispensing of films from the magazine 24 is stopped when the switch rail 25 is in the position indicated in broken lines, in order to prevent two films from being conveyed simultaneously into the developing machine 8.

Claims (13)

1. Apparatus for unloading radiation-sensitive film from a container and for conveying the film to a developing machine, comprising an unloading station at which said container is opened and said film is extracted therefrom at a first, relatively high speed, a feeding station at which said film is fed to the developing machine at a second, relatively low speed, and a film conveying system for conveying said film from the unloading station to the feeding station, the conveying system including a drive which is operable at least at two different speeds such that said film can be conveyed selectively at speeds which are matched to said first and second speeds, respectively.

2. Apparatus as claimed in claim 1 , wherein the conveying system also includes at least one pair of rollers which are driven by said drive, the rollers in each pair receiving said film therebetween to convey the latter.

3. Apparatus as claimed in claim 2, wherein the conveying system includes at least two such pairs of rollers which are driven at the same but changeable speed by a common drive.

4. Apparatus as claimed in claim 1,2 or 3, wherein the conveying system includes a sensor which detects leading and trailing ends of said film, and the speed of said drive is changed in response to such detection by the sensor.

5. Apparatus as claimed in claim 4, wherein the sensor is in the form of a light barrier and comprises a light source and a light-sensitive detector disposed on opposite sides of the film path.

6. Apparatus as claimed in claim 5, wherein the light source is an infra red light source.

7. Apparatus as claimed in claim 4, 5 or 6, wherein the feeding station includes a pair of rollers which receive said film therebetween to feed the latter, and the conveying system is arranged along a line extending between the unloading and feeding stations, the distance between the sensor and the rollers at the feeding station being at least equal to the longest film to be conveyed.

8. Apparatus as claimed in any one of claims 1 to 6, wherein said drive is reversible such that the conveying system conveys said film from the unloading station in one direction and subsequently conveys said film to the feeding station in the opposite direction.

9. Apparatus as claimed in claim 8 when appended to claim 4, wherein the direction of said drive is reversed in response to said detection by the sensor.

10. Apparatus as claimed in claim 8 or 9, wherein said film is extracted from the container at the unloading station generally in a first plane and is fed to the developing machine generally in a second plane, the first and second planes being generally mutually parallel, the conveying system conveys said film generally in a third plane which is oriented transversely to the first and second planes, and deflection means is provided to deflect said film from said first plane to said third plane and from said third plane to said second plane.

11. Apparatus as claimed in any preceding claim, further comprising a film store in which said film can be stored prior to being fed to the developing machine, and a selector device which is operable to direct said film from the unloading station selectively to the conveying system and the film store.

12. Apparatus as claimed in claim 11 when appended to claim 10, wherein the film store is disposed on a side of said first and second planes opposite to the conveying system.

13. Apparatus for unloading radiation-sensitive film from a container and for conveying the film to a developing machine, substantially as hereinbefore described with reference to any one of Figures 1 to 3 of the accompanying drawings.