Device for loading and unloading X-ray film cassettes

A device for loading and unloading X-ray film cassettes into a light-sealed compartment includes a device for opening a lid of the cassette inserted in the compartment. The lid-opening device comprises a motor-driven control disc which via a crank rod shifts a support carrying a cassette positioning device, and a lid-opening hook which can swing in two normal directions and cooperates with the lid of the cassette to open the latter.

BACKGROUND OF THE INVENTION 
The present invention relates to a device for loading and unloading X-ray 
film cassettes. 
Devices for loading and unloading X-ray film cassettes of the foregoing 
type have been known. Such a device comprises a subframe which includes a 
light-tight closable compartment for receiving a cassette which has a 
pivotable lockable lid, means for the insertion and removal of the X-ray 
film cassette into and from the compartment, a device for positioning 
cassettes of all available formats, an unlocking device coupled with the 
positioning device for locking and releasing the lid of the cassette, a 
support movable with the cassette from the first position to the second 
position and supporting the positioning device and the unlocking device, 
means for driving the support, and a device for opening the lid of the 
cassette during the movement of the cassette and support from the first to 
the second position. 
Such a device has been disclosed, for example in DE-PS No. 32 32 187. In 
such a device, a necessary adjustment of the movements of the cassette and 
support and the device for opening the cassette lid involves a great deal 
of expense. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide an improved device for 
loading and unloading X-ray film cassettes. 
It is a further object of the invention to provide a simple control device 
for adjusted movements of the support and lid-opening device. 
These and other objects of the invention are attained by a device for 
loading and unloading X-ray film cassettes each having a pivotable 
closable lid, the device comprising a base having a light-tight closable 
compartment accommodating a cassette, transporting means for inserting and 
removing said cassette from said compartment, positioning means for 
positioning a cassette edge for the cassettes of all formats; a movable 
support; releasing means coupled to said positioning means for lid locking 
and a closing means for the lid which are positioned on said support 
movable jointly with the cassette in a transport direction from a first 
position to a second position; drive means for moving said support; and 
lid-opening means for opening said lid during the movement of said support 
with said cassette from the first position to the second position, said 
drive means for said support and said lid-opening means including a 
motor-driven control disc, a shiftable crank rod rotatably eccentrically 
supported on said disc, and a plate guided on said crank rod and having an 
opening hook cooperating with the lid to open the lid. 
The support may be formed by a turnable guide rod, extending transversely 
to the transport direction, said rod having ends, said drive means for 
said support including a toothed piece at each end of said guide rod and 
gears each meshing with a respective toothed piece and being supported on 
said guide rod, said crank rod having an end supported on the end of said 
guide rod such that upon rotation and shifting of the end of said crank 
rod said gears roll on said toothed pieces and said guide rod executes a 
parallel motion in the transport direction. 
The control disc may include an eccentrical pin engaged in a cam slot of 
said plate. 
The plate may have a control pin, said control disc having a cam piece, 
said pin lying on said cam piece in a force-locking fashion. 
The planes of said control disc and said plate are parallel to narrower 
sides of the cassette extending in the transport direction, said hook 
being tiltably supported on said plate about a pivot axis positioned 
parallel to said planes and tiltably supported about a further pivot axis 
transversal to said planes; and further including springs and stops, said 
hook being drawn by a respective spring towards a respective stop in each 
tilting direction. 
The one pivot axis may croos said further pivot axis. 
The plate may have a portion which carries one of said stops and is 
pivotably supported about said further pivot axis on said plate and is 
connected therewith by one of said springs, said pivot axis together with 
said hook being supported on said portion and being connected therewith by 
another of said springs. 
The hook may be a double-arm and has one end cooperating with said lid, 
said one end having a downwardly directed oblique surface, said hook 
having at another end thereof an angled portion said plate having a 
control recess in which said angled portion is engageable. 
Due to the device according to the invention, namely due to the provision 
of the control disc in the drive means, a synchronous and adjustable 
movement of the support and the lid-opening means is ensured. Such an 
arrangement also permits that with the non-released cassette lid or with 
the insertion of the cassette which is not to be processed into the device 
the lid-opening hook provided with three degrees of freedom does not 
engage with the lid so that no damage either to the device or to the 
cassette can occur. 
The hook may have a conical projection extending parallel to said pivot 
axis, said base having an oblique surface, said projection engaging said 
oblique surface in an initial position of said plate, with said another of 
said springs being stressed in one position of said hook pivoted from said 
lid, said oblique surface being formed so that said conical projection can 
slide off said oblique surface upon pivoting of said plate. 
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 contruction and its method or 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 drawing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawings in detail, and firstly to FIG. 1 thereof it 
should be noted that only those structual components which are important 
to the present invention are shown whereas conventional parts of the 
device for loading and unloading x-ray film cassettes have been omitted 
for the sake of clarity. Reference numeral 1 designates a compartment of a 
base or subframe for accommodating a cassette; reference numeral 2 denotes 
transporting means for the insertion and withdrawal of the cassette. The 
cassette transporting means can be formed by transport rollers positioned 
at the bottom of compartment 1. Reference numeral 3 designates a 
schematically shown means for a light-sealed locking of an insertion 
opening 4 of compartment 1. At the front side of the device is positioned 
conventional means 5 and 6 for releasing of the cassette as will be 
described herein below. For a repeated locking of the cassette thesemeans 
can operate so that a slide 5 which has a non-shown toothing be engaged 
with a locking bar of the cassette and then actuate the locking bar by 
moving transversely to the cassette transport direction 7 so that the 
cassette would spring out, for example under the action of weak springs. 
Rotatable cams 6 serve the purpose of a complete locking of the lid after 
a new cassette has been loaded into the compartment 1. A pair of releasing 
and locking means 5, 6 must be displaceable in the directions 8 
transversal to the direction 7 of the insertion of the cassette so that 
the releasing and locking device would be automatically adjustable to 
various sizes of the cassettes utilizable in the device of the present 
invention. Above and/or at the devices 5, 6 for releasing and locking a 
cassette inserted in the compartment 1, are arranged conventional means 9, 
10, 11 for the removal of a film sheet from the cassette as well as for 
the insertion of a new film sheet into the cassette. This 
loading-and-unloading means comprises substantially controlled suckers 9 
and corresponding transport roller pairs. Also a film storage magazine 
(non-shown) is provided in the known fashion, which magazine contains 
films of different formats which are loaded into the cassettes adapted to 
such different formats. Furthermore, an intermediate magazine for 
collecting films removed from the cassettes is provided in the known 
manner (also not shown). Such an intermediate magazine can be connected 
directly to a film developing machine. For the drive of the transport 
device 2, suckers 9 and transport means 10, 11 are provided in the known 
fashion with electric motors 15, 16, 17. 
The determining of the format of the given cassette and selection and 
feeding of a new film take place automatically after an automatic 
measurement of at least one side of the cassette. When two types of the 
cassette are to be used in the loading-and-unloading apparatus which are 
equal with the cassette side measured or are very close to the same, then 
also the vertical cassette dimension is automatically measured and the 
format of the cassette is determined by two sides perpendicular to each 
other. Before the determination of the format of the given cassette the 
latter must be precisely positioned. 
Reference numeral 18 designates the cassette. A possible positioning device 
with a clamping lid 19 will be now described in detail. This positioning 
device is operated to position a vertical front cassette side 18a in the 
direction of the insertion 7. Thereby a displacement device for 
transversal displacement to the direction 7 is required. This displacement 
device must be reciprocally movable in the directions of arrows 8. This 
transversal displacement device includes a clamping jaw 12 formed as an 
angular piece 12a, 12b which, at the same time, carries moveable parts 5, 
6. The latter are movably supported on a transversal rotational rod 13 in 
respect to the non-rotational clamping jaw 12. Devices 5, 6 are shown in 
FIG. 1 in the intermediate position. The clamping jaw 12 is displaceable 
relative to the transversal direction 8, in respect to a stationary 
clamping jaw 14 formed also by an angular or right-angled piece 14a, 14b. 
Arms 14a, 14b thus form a lateral and a front-side stop or abutment for 
the cassette 18, 19 transported by means of transport rollers 2 into 
compartment 1. The two clamping jaws 12, 14 are arranged on the rod or bar 
13 so that arms 12b and 14b are in alignment with each other. The cassette 
movable against stops 14a, 14b is merely clamped by the movable clamping 
jaw 12 and positioned thereby. The cassette transported between the 
clamping jaw 14 and the movable clamping jaw 12 in the initial position 
is, upon the displacement of the clamping jaw 12 moved under an additioanl 
action of the further rotating transport rollers 2, towards the stops 14b, 
12b and aligned between arms 14a, 12a. Switch contacts are provided at the 
arms 14b, 12b or, with the large cassettes, between those arms. The switch 
contacts switch on a non-shown drive for the movable clamping jaw 12 upon 
the occurrence of a new inserted cassette 18. The switch can be, for 
example, a light barrier switch or a microswitch. In the initial position 
of the clamping jaw 12, is provided, for example a flap in the measuring 
range of the ligh-barrier switch or the like, by means of which a counter 
cooperating with a comparator is switched on when the movement of the 
clamping jaw 12 starts. The structures of the counter and comparator as 
well as the switch are not of importance for this invention. 
The device illustrated in FIG. 1 is designated so that after the 
positioning and determination of the format of the inserted cassette 18, 
19 the latter together with the support or rod 13 for structural 
components 5, 6, 12, 14 is moved further, on the one hand by a further 
rotation of the transport rollers 2 and, on the other hand, by shifting 
the support 13 in the direction of arrow 7. During this movement the 
locking means for the cassette lid 19 is released by a known control by 
means of the cassette releasing device 5 so that lid 19 can yield under 
the action of springs. During the corresponding movement in the opposite 
direction for the discharge of the newly loaded cassette, lid 19, after 
the release of its lock, will be pushed again by slide 5. During the 
insertion movement of the cassette 18, 19 but after the lid release and 
before reaching the loading-and-unloading position, the released lid 19 is 
further opened so that the film removal and repeated loading of the 
cassette are possible. The proposed device ensures a simple mechanical 
coordination of the transport device for the support 13 and the control of 
the device for opening the lid 19. 
Support 13 is therefor formed, as mentioned above as a turnable rod on 
which are supported elements 5, 6, 12, 14 so that the latter can take 
definite, e.g. certain positions relative to the apparatus by a mechanical 
control means or supporting means. The support arrangement 13 with 
elements 5 and 6 is known and disclosed, for example in DE-PS No. 32 32 
187 corresponding to U.S. Pat. No. 4,590,738. At the ends of the guide or 
supporting rod 13, are secured gears 20, each engaged with a respective 
rack 21 extending in the transport direction 7. Both gears 20 as well as 
two racks 21 are identical to each other so that, upon the rotation of one 
of two gears 20 and/or the rod 13 the other gear 20 is taken along and rod 
13 or the parts 5, 6, 12 and 14 supported thereon execute a parallel 
shifting in the transport direction 7. The drive of rod 13 is performed by 
an electric motor 22 or its drive pinion 23 which is in engagement with a 
control disc 24 and drives the latter. A crank rod 25 is eccentrically 
supported on the control disc 24. The other end 25a of the crank rod 25 is 
connected near gear 20 with the end of rod 13. If, after the positioning 
of the inserted cassette 19, 20 motor 22 is switched on by the known 
control, the control disc 24 due to the translation of the slow rotation 
and the rotating end 25a of the crank rod 25 will be shifted in the 
transport direction 7 and rod 13 will turn whereby gears 20 will roll on 
the respective racks 21 by the same amount. Thus a sliding guidance for 
the rod 13 can take place by means of gears 20 and racks 21. Such a motion 
at the first rack 21 by the slide 5 results in the release of the cassette 
lid 19. 
After the release of the lid 19 this lid should be lifted to be 
sufficiently open. The lifting process must start at the predetermined 
position of rod 13 moved by the crank rod 25 and end at a further position 
before an automatic switching off the motor 22. A simple mechanical 
control of the device 26 for opening the lid 19 is thus possible because 
its movement derives from the crank rod 25 or the drive disc 24. 
The planes of the control disc 24 and plate 27 (FIGS. 2 to 6) of the 
lid-opening device 26 are parallel to the cassette narrow side 18b 
extending in the direction of transporting 7. Plate 27 is pivotably 
supported about a pivot axis 28 which is fixed with the base of the 
device. The lid opening device 26 further includes cams 29, 30 forcibly 
guided between plate 27 and control disc 24. The cam 29 and cam pin or 
follower 30 cooperating with the latter can be formed by an eccentric pin 
on the control disc 24 and by a cam slot in the plate 27, respectively. 
According to the exemplified embodiment the eccentrically positioned 
control pin 30 of plate 27 is engaged in a force locking manner with the 
cam 29 of disc 24, which cam is formed in accordance with a desired 
movement, whereby the non-shown spring produces the force locking 
engagement or such a force -locking engagement can be ensured by the force 
of gravity. Upon the movement of the control disc 24, and also during the 
further transportation of the cassette 18 within the device in the 
direction 7, plate 27 is lifted in the counter clockwise direction in FIG. 
2 and 3 or in the clockwise direction in FIG. 1. 
The free end of plate 27 lying near the cassette side 18a supports an 
opening hook 31 which can be engaged in a recess 19a of the lid 19, which 
is accessible at the side 18b of the closed cassette. The hook 31 is 
supported on the plate 27 so that hook 31 can tilt about a pivot axis 33 
which is normal to the plane of plate 27. Hook 31 is also biased by 
springs 34, 35 (FIG. 4) against respective stops 36, 37. Thereby such a 
support is provided that a plate piece 38 pivotally positioned on plate 27 
about the further pivot axis 33 is clamped or tensioned together with the 
plate by spring 35, and the pivot axis 32 together with opening hook 31 is 
supported on the plate piece 38, and is clamped or tensioned with this 
plate piece by the other spring 34. The opening hook itself is formed as a 
two-arm element. The end of the opening hook 31 cooperating respectively 
with the cassette lid 19 or the recess 19a has a sloped or inclined 
surface 31a directed downwardly from the lid 19. The other end of the 
opening hook 31 has an angled portion 31b which is brought into engagement 
with a control recess 27a formed in the plate 27. Finally, an oblique 
surface is provided on the opening hook 31 parallel to the pivot axis 32. 
The oblique surface is formed preferably by a conical piece or projection 
39 which engages in the non-operative or initial position of plate 27 a 
control surface 40 which is stationary or housing-fixed under the clamping 
action of the other spring 34 in the position of the opening hook 31 
pivoting away from the cassette narrow side 18b. The housing-fixed control 
surface 40 is thereby arranged and formed such that the conical piece 39 
can upon pivoting of the plate 27 upwardly, slide off the control surface 
40. 
The mode of operation of the lid opening device 26 is as follows: 
If, after the positioning of the cassette 18, 19, the control disc 24 is 
rotated the opening hook 31 is firstly pivoted, by means of the control 
surface 40 and the conical piece 39 from the adjacent side 18b of the 
cassette. The end 31b of the opening hook is positioned against the 
control recess 27a. The support 13 has been already shifted in the 
transport direction 7, and the locking of the lid is released by means of 
the releasing device 5 shown in Fit. 1. If this motion phase is reached 
the plate 27 is also pivoted about the angular piece upwardly so that the 
conical piece 39 is pulled down by the control surface 40. The opening 
hook 31, 31a falls into the recess 19a of the released lid 19, while the 
angled end 31b is in the recess 27a. Upon further rotation of the control 
disc 24 the support 13 is further shifted and the opening hook 31 together 
with the lid 19 are further pivoted upwardly until they reach the position 
for the unloading of the cassette. After a renewed loading of the cassette 
the entire process is executed in the reverse fashion until the hook 31, 
31a is brought by the control surface 40 again into contact with the lid 
19, and the lid is pushed back by the locking device 6. 
If, for example the cassette inserted into the compartment 1 has not been 
intended for processing in the device and its lid is not releaseable or 
for any other reasons the release of the lock of the lid is discontinued 
the opening hook 31, 31a is engaged in accordance with the respective 
motion stage, in the lid recess 19a as shown in FIG. 5. The lid 19a can 
not, however be lifted then so that firstly the spring 35 is stressed, and 
the plate piece 38 together with hook 31 are pivoted relative to the plate 
27. Thereby the angled portion 31b which is positioned in the recess 27a 
will be pulled from the latter by the lower edge of the control recess 
27a, as could be clearly seen from the comparison of FIGS. 5 and 6. The 
hook 31, 31a, 31b will be therefore pivoted from the narrow side 18b of 
the cassette and from the lid recess 19a (FIG. 6). Thus no damage could be 
done to the cassette that has not been unlocked by device 26 if such a 
cassette were inserted into compartment 1 by mistake. It is also possible 
to connect the entire process with an alarm device which would indicate 
any disturbance occurring. The angled hook portion 31b engageable in the 
control recess 27a and the control recess 27a independently from hook 
portion 31b could each be provided with an electrical switch which would 
release an alarm device during the actuation of only the control recess 
27a. The sloped surface 31a brings about the additional advantage, which 
resides in that the hook 31 could be engaged in the lid recess 19a only 
when small height tolerances are provided. Eventually both ends 31a and 
31b of the hook can be also formed in the direction of elongation of hook 
31 normal to both axes 32 and 33 resilient relative to each other to be 
pressed together in the direction opposite to that shown in FIG. 4. 
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 
devices for loading and unloading x-ray film cassettes differing from the 
types described above. 
While the invention has been illustrated and described as embodied in a 
device for loading and unloading x-ray film cassettes, 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 relveal 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.