Note: Descriptions are shown in the official language in which they were submitted.
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~ his invention relates to apparatus for automatically
unfastening and opening radiographic film cassettes.
Such apparatus is used for example in medical centres
where large numbers of radiographs have to be processed
each day. The cassettes containing exposed radiographic film
sheets are placed in a predetermined position in the unfas-
tening and opening apparatus and this operates in conjunction
with some kind of film transfer device whereby the film
sheets are automatically transferred from the cassettes
into a processing station in which the film sheets are
automatically developed.
~ he present invention provides a cassette unfastening
and opening apparatus which departs from convention in that
it is constructed to receive and handle cassettes in an
inverted orientation.
Radiographic cassettes of different standard designs
are in use but all or most of such cassettes are alike in
comprising two hinged parts, namely a tray-like container
which receives the film sheet, and a lid which can be fasten-
ed in closed posrtion by fastening means at the cassettefront (i.e. the cassette boundary opposite the lid hinge).
~he lid comprises a top plate which closes into a position
inside the peripheral walls of the container part and which
itself has no depending wall or flange, at least not at
its front edge. ~he present invention is concerned with
apparatus for unfastening and opening cassettes having
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those features. Such cassettes are hereafter identified
to as "cassettes of the type referred to".
~he apparatus according to the invention has a cassette
receiver for receiving a cassette of the type referred to
in inverted orientation, such receiver having or being
associated with locating means for locating a said cassette
in predetermined position in such receiver; a cassette un-
fastening mechanism for automatically unfastening a cassette
located in such predetermined position, and means for auto-
matically opening an unfastened cassette, while it is in
said predetermined position, by hinging the container part
of the cassette upwardly relative to its lid.
When a cassette con-taining a radiographic film sheet
is opened by apparatus according to the invention the film
sheet is resting on the inside surface of the cassette lid.
Because of this fact, it is much easier to arrange for
reliable automatic displacement of the film sheet to a pre-
determined posi~on outside the cassette, the comparison
here made being with conventional apparatus such as described
in U.S.Patent 3,105,903 of Karel Sano and Willy Karel Van
Landeghem issued October 1, 1963 in which the film
sheet lies within the container part of the cassette. In
preferred apparatus according to the invention, the receiver
is disposed so that when a cassette is in position therein
the cassette is in an inclined posi-tion with its front end
lowermost, the inclination being such that on opening of
the cassette the fiIm sheet will slide forwardly out of the
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cassette, along the inner surface of the cassette lid. An
inclined ramp may be arranged forwardly of the cassette
receiver so that the film sheet leaving the cassette slides
directly onto and down such ramp to a delivery point.
~ he invention as hereinbefore broadly defined includes
apparatus having any one or more of the following further
features which are recited as examples of optional features
affording special advantages.
(1) ~he cassette unfas-tening and opening apparatus is in
the form of a unit which can be mounted as such at the
entrance of a radiographic film sheet processing machine and
includes a film sheet transfer means for effecting automatic
delivery of a film sheet from an opened cassette through
an exit point of the unit from which the sheet can enter a
said processing machine. ~he transfer means may comprise
an inclined ramp as already referred to. ~ilm sheet trans-
port rollers may be provided adjacent such ramp for positi-
vely propelling the film sheets from the apparatus.
(2) ~he cassette unfastening and opening apparatus is in
the form of a unit having a light-tight houslng within
which the unfastening and opening mechanism is accommodated,
the housing having a door, shutter or analogous means via
which access can be gained to the interior of the housing
for inserting a loaded cassette into the cassette receiver
and withdrawing the cassette after removal of the film
sheet therefrom. It is an advantage if the apparatus can
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be operated in daylight conditions. If feature (1) above
is employed the cassette unfastening and opening unit can
be fitted to a film sheet processing machine installed in
daylight or in a brightly illuminated room, e.g., in a medical
operating theatre where the processed radiographs will be
directly available for inspection. The aforesaid unit
housing may have a separate film sheet feed passage, closable
by a light-tight cover, via which a film sheet can be fed
(in the dark) directly into a said processing machine.
(3) The cassette opening mechanism includes a part disposed
and operating so as to exert upward cassette opening force
on one or more of the side and front walls of the container
part of the cassette.
(4) The cassette receiver is formed with an upwardly opening
guide channel for receiving a side wall of the container
part of a cassette when this is inserted into the cassette
receiver, and the cassette opening mechanism operates by
tilting the receiver to cause it to lift such container part.
(5) The cassette opening mechanism includes a lever which
is pivotally mounted and operates to make contact and raise
a component which engages the container part of a cassette
when this is in position in the cassette receiver. Such
component may be the receiver or a component part of the
receiver. The pivotal movement of the lever may be achieved
by some form of cam mechanism, e.g. by a motor-driven disc
having a projection on which the lever slidingly rests.
GV.890 PCT _ 4
109~875
(6) The cassette unfas-tening mechanism includes one or
more members for applying opening force on the operating
lever(s) of (a) cassette fastener(s), such member or
members being located in such relationship to the cassette
receiver that as a fastened cassette is inserted into the
predetermined position in such receiver,a portion of the
or each lever passes below the or a said member. For
example the or each said member of the cassette unfastening
mechanism may be part of or carried by a pivotally mounted
component which is connected by one or more belts, cords
or analogous means to a motor-driven disc or other rotatable
part so that during a rotation of the latter said component
is moved pivotally in a direction which causes displacement
of the related cassette fastener lever into open position.
Reference has been particularly made herein to appara-
tus wherein displacement of a film sheet from an opened
cassette takes place by sliding movement of the film sheet
under gravity. However the invention includes apparatus
which functions to unfasten and to open a cassette while it is
in horizontal position. In such case some other arrangement
will be made for removing the film sheet from the cassette.
For example use can be made of one or more transfer arms
which operate(s) on the film sheet by friction or suction.
Instead of providing a cassette opening mechanism which
operates by exerting upward force on one or more of the side
and front walls of the container part of -the cassette, the
GV.890 PCT _ 5 -
1092~375
cassette opening mechanism of apparatus according to the
invention may operate in some other way. For example such
mechanism may incorporate one or more suction cups which
act against the exterior bottom surface of the container
part of the cassette.
Although reference has been particularly made to the
use of apparatus according to the invention in direct asso-
ciation with a film sheet processing machine, apparatus
according to the invention can be used for other purposes,
e.g., it can be used in combination with a magazine for
temporarily storing exposed film sheets preparatory to bulk
processing of the contents of the magazine.
Certain embodiments of the invention, selected by way
of example, are illustrated in the accompanying diagrammatic
drawings, wherein :
Fig. 1 is a cross-sectional view of an apparatus according
to the invention;
Fig. 2a and 2b show part of the mechanism for unlocking
a cassette;
Fig. 3 is à view of the mechanism for opening a cassette;
Fig. 4 is a cross-section on line 4-4' of Fig. 3;
Fig. 5 shows a possible relationship between the cassette
container, lid and fastening lever(s), and a member for
unfastening the cassette;
Figs. 6 and 7 are detail views representing the operation
of an alternative form of a cassette opening mechanism.
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~ he illustrated apparatus is designed for unfasten-
ing and opening radiographic film cassettes in daylight
conditions and for feeding the film sheets from the open
cassettes into the entrance slot of a processing machine.
~ he apparatus 10 comprises a housing 11, fixedly
secured by known means to the frontside of a processing
machine 12 or of another device (not shown) for storing
exposed radiographic films. lhe housing is provided with
a hinged flap 13 which can be hinged upwardly from the
illustrated positlon to close the housing light-tightly.
~he hinge component on the flap engages slots in the body
of the housing so that the flap after being hingedly closed
can receive a slight translational movement, imparted via
its handle 17, for lccking the flap. ~he flap is supported
in its open position by a strut 16 having a slot in which
a pin on the housing body engages.
In order to load the apparatus, a cassette containing
a radiographic film sheet is inserted into a guide 19
located within the housing 11, the flap 1~ of course being
open. ~he cassette is inserted into the guide 19 front
end first and in inverted orientation, i.e. with its lid
facing downwardly. ~he front end of the cassette is the
end where the cassette fastener(s) is or are located. As
will become apparent from the later description the guide
19 serves a dual purpose. It locates the cassette in a
predetermined lateral position within the housing of the
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apparatus, and it serves for holding and upwardly hinging
the container portion of the cassette. As shown in Figures
1 and 3 the guide 19 is pivotally connected to an arm 20
which itself is freely rotatable around a shaft 21.
~ he cycle for unfastening, opening and unloading the
cassette 14 is started when a hook portion 18 on the ver-
tical rear wall of the flap 13 engages the actuating arm
of microswitch 380 If desired, this start may be indicated
by means of control signals (not represented) and the closing
of the microswitch 38 may also actuate a supplementary
locking mechanism for locking the housing flap closed and
thus prevent accidental opening thereof.
When the cassette is in correct position in the guide
19, the cassette engages the contact of a microswitch 25
in an operating circ-uit of a cassette unfastening mechanism.
On commencement of the unfastening and opening cycle this
unfastening mechanism is started and operates to
release the cassette fastener(s). lhe details of this un-
fastening mechanism will be described later with reference
to Figure 2.
Once the cassette fastener(s) has or have been released
a lever 22 having an end portion 23 is caused to swing up-
wardly about a spindle 2~. ~he lever portion 23 engages the
guide 19 and causes it to tilt upwardly as permitted by
its aforesaid pivotal connection with shaft 21 via arm 20 and
by the manner of its engagement with the container part of
the cassette.
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As the cassette is in an inclined position, the film
sheet within the cassette falls out of it as the cassette
is opened. ~he film sheet slides downwardly along the
inside face of the cassette lid and travels on downwardly
towards rollers 26 and 27 which will feed it through the
entrance slot of a processing machine 12 a part of which
is shown. ~uring its descent the film engages the contacts
of microswitches 28 and 29. One of these microswitches
controls the rotation of a motor 30 which drives the rollers
269 27 via a driving belt. ~he other microswitch activates
an identification unit 34 functioning as described hereinafter.
When the film sheet reaches the nip of rollers 26, 27
they are stationary. ~he motor circuit includes a timer
32 which delays effective rotation of the rollers 26, 27
until a few seconds after the impact of the film sheet
against such rollers. If the film sheet is skewed when it
contacts the rollers it becomes squared before the resulting
rotating movement of the rollers commences. Consequently
it is ensured that the sheet is properly orientated in its
own plane before it becomes advanced to the processing
machine.
In a preferred embodiment of the apparatus, the time
delay between impact of the film against the transporting
rollers and the commencement of film advance by such rollers
amounts to five seconds. If desired, the time switch 32
may be of a double cycle type and operatesfirst to start
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the rollers rotating in reverse sense when the film sheet first
contacts the rollers, then to stop the rollers and subse-
quently to start rotation of the rollers forwardly for
propelling the film sheet into the processing machine. It
will be appreciated that in the second case the chance
of a film sheet being advanced by the rollers in skewed
condition is even less than in the case that the rollers
are driven forwardly initially. Instead of the pair of
rollers 26, 27 sheet transporting means of some other kind
can be used, such as a pair of endless belts.
As the film sheet is driven forwardly by the rollers
26, 27 the leading end of the film sheet contacts the arm
of a microswitch 33 which keeps the roller driving motor
in operation until the trailing edge of the film sheet has
passed. lhe apparatus is then ready for another feeding
cycle. Microswitch 33 may also control release of the sup-
plementary locking mechanism for the housing flap 13 so
that this can be slightly retracted and hinged open to
enable another cassette to be inserted into the apparatus.
Each time a microswitch is actuated, signal means may be
energized in order to enhance the ergonomic characteristics
of the apparatus.
~ he identification unit 34 serves to print supplemen-
tary information upon the film sheets to be processed.
lhe unit may comprise a flash unit, a small optical system
and a holder for the original bearing the data to be printed,
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e.g., a card 35 bearing typewritten data. ~he releasedfilm sheet travels along the image plane of the optical
system. ~he flash unit may be operated automatically when
the leading edge of -the film sheet contacts the arm of one
of the microswitches 28 and 29 as already mentioned.
If desired, the apparatus 10 may be provided with
a separate passageway 36 through wich exposed film sheets
may be directly fed into the processing machine from a
darkroom. When using the apparatus in daylight or artifici~l
light, the passageway 36 has to be screened off, e.g., by
means of a cover 37.
In Figures 2a and 2b is represented the mechanism for
unfastening the cassettes. ~his mechanism comprises a disc
40 driven by suitable motor means (not shown). ~he disc
carries a pin 41 to which a flexible driving belt 47 is
attached. (A cord or other suitable member may be used
instead of a belt). ~he belt is supported by pulleys 42,
43, 44, 45 and 46 and is connected with a pin 48 provided
to a rocker 49. ~he rocker 49 is pivotally mounted on a
fixture 50 having an abutting lug 51. During a complete
rotation of the disc 40 the rocker 49 is caused by virtue
of its attachment to the belt 47 to oscillate about its
pivot. The rocker first rocks clockwise in the aspect of
Figure 2a so that the abutting lug 51 moves downwardly.
~ach cassette has a pivoted fastener-release lever (54 in
Figure 5) which when the cassette is in its inverted position
GV.890 PC~ - 11 - '
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has to be swung downwardly about its pivot in order to
release the fastener. ~he location of the abutting lug 51
in the apparatus is such that when the cassette is inserted
int~ the guide 19 (~igure 1) as hereinbefore described the
fastener-release lever passes below such lug as suggested
in Figure 5. During the clockwise movement of rocker 49
as above described, the lug 51 abuts against the ~astener-release
lever and moves it into its release position.
~or the sake of simplicity, the apparatus chosen for
illustration is one for unfastening and opening cassettes
having only one fastener at its front end. '~he mechanism
represented in Figures 2a and 2_ extends transversely of the
apparatus in front of the cassette guide 19 (Figure 1) so
that the position of lug 51 coincides with the single
fastener. If the unfastening apparatus is required for
handling casssttes with twin fasteners, e.g. one at or ad-
jacent each front end corner of the cassette, to unfasten-
ing mechanisms as described with reference to ~igures 2a
and 2b will be provided, one for each fastener.
As appears from Figure 2b, two microswitches 52, 53
are located adjacent the disc 40. 'lhe actuating arms of
these switches are contacted by the rim of the disc. 'lhis
rim is formed with a recess or with recesses which when
in register with a microswitch arm allow it to move to
open or close the switch. In this manner one or ~ore
operations in the cycle of the apparatus can be controlled.
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For example switch 52 may operate to stop the disc motor
after one complete revolution and switch 53 may initiate
a next step in the cycle of the apparatus.
The next step in the cycle is the opening of the
cassette 14. As already mentioned the cassette guide 19
participates in this operation. As appears from ~igure 4,
the guide 19 has a depending side wall at the bottom of
which is an upwardly opening internal channel. When a
cassette is pushed into the guide, the free edge of one side
wall 65 of the container section of the cassette travels
within the said internal channel. Between the side wall
65 and the closed cassette lid 66 there is sufficient
clearance to accommodate to the inner side wall of the said
channel. It will now be apparent that when the guide 19
is tilted upwardly by the action of lever 22 the guide
will carry with it the container section of the cassette.
~ igure 3 shows how the lever 22 is operated. ~he
lever is pivoted on a shaft 24 under the influence of a
motor 60 which drives a disc 61, if desired through the
intermediary of a reduction gear (not shown). On the disc
61 a support 62 is provided upon which the lever 22 rests.
~he support 62 may e.g., be in the form of a small roller
in order to reduce friction between the lever 22 and the
support 62 to a minimum. During one complete revolution
of the disc 61, the lever 22 oscillates through a certain
angle, the amplitude of its movement being sufficient to
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ensure that the container section of the cassette is
raised far enough to allow unimpeded sliding movement of
the film sheet out of the cassette.
~ he alternative form of a cassette opening mechanism
represented by ~igs. 6 and 7 is intended for opening cassettes
having a hole formed in the front wall of the container part
of the cassette. ~he mechanism comprises a solenoid having
a coil 69 and an axially displaceable core 68 for entering
a hole 67 in such front wall of the cassette 14. ~he sole-
noid coil is energised via an electric circuit including aswitch 71 and a battery 72. ~he solenoid is mounted on
a carrier (not shown) which can be displaced by a suitable
mechanism for opening the cassette. Such mechanism may
e.g., operate in a similar way to the mechanism comprising
lever 22 in the apparatus described with reference to
~igs. 1 to 5. Prior to the commencement of an operative
cycle of the cassette unfastening and opening apparatus,
the solenoid is in such a position in the apparatus that
its core is in direct ali,gnment with the hole 67 in the
container part of the cassette when the cassette occupies
the predetermined position ready to be unfastened. In this
case the cassette carrier may merely comprise a cassette
support and guide means for laterally locating the cassette
in its predetermined position. On energisation of the
solenoid the core 68 enters the hole 67, this movement
being limited by abutment of a collar 70 on the core
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against the wall portion surrounding the hole. ~hen the
solenoid displacing mechanism is operated to cause upward
movement of the solenoid as indicated in ~ig. 7 and
consequent upward hinging movement of the container part
of the cassette about its hinge 73. ~he solenoid switch
71 can be actuated by the cassette as it is pushed into
its predetermined position within the apparatus or can
be actuated in the same way as switch 53 (Fig. 2b) in
the apparatus described earlier so that the solenoid is
energised on completion of the cassette unfastening operation.
GV.890 PC~ - 15 -
