GB1583436A

GB1583436A - Plate making system

Info

Publication number: GB1583436A
Application number: GB1753878A
Authority: GB
Original assignee: Sun Chemical Corp
Current assignee: Sun Chemical Corp
Priority date: 1977-06-02
Filing date: 1978-05-03
Publication date: 1981-01-28
Also published as: CA1106217A; NL7806061A; DE2824088C2; AU522109B2; DE2824088A1; AU3647478A

Description

(54) PLATE MAKING SYSTEM (71) We, SUN CHEMICAL CORPORATION, a Corporation organised and existing under the laws of the State of Delaware, United States of America, of 200 Park Avenue, New York, New York, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to a plate making system, and more specifically to a high speed plate making system for producing a plurality of plates which can be used in a printing process, such as a newspaper printing process, from a single negative. The invention also relates to a method of exposing a plurality of thin printing plates from a single stationarily mounted film negative.

Daily newspapers are now converting to a printing process using a thin aluminium plate with a so-called "wipe on" coating or pre-sensitized coating in place of a letter press type arrangement. Most newspapers will run a large number of plates of the same page, thus requiring that a large number of plates be made from the same negative. The production of a large number of plates which are all appropriately aligned with a given negative has been a time-consuming process.

Numerous devices are known to make a plurality of plates from a single negative.

Devices of this type are shown in U.S.

Patent Nos. 3 635 559, 3 810 694 and 3922087.

The present invention in one aspect provides a plate making system comprising support means for supporting a stack of aluminium photographic plates with their emulsion side facing downward, a film negative carrier for supporting a film negative in accurate registry with the said stack, the said film negative carrier having an upper surface at about the same height as the top of the stack, plate exposure lamp means disposed beneath the film negative carrier for exposing plates disposed on top of the film negative carrier through a negative fastened thereon, first transfer means adapted to contact the back surface of the uppermost plate of the said stack of plates and to move the said uppermost plate, with its emulsion surface facing downward, onto the film negative carrier, second transfer means adapted to contact the back surface of a plate on the film negative carrier and to move the said plate, and invert it to have its emulsion side facing upwardly, and to deposit the plate onto an output means for delivering an exposed plate from the said system, with its emulsion side facing upward, to a photo-processing unit for developing the plate.

The invention in another aspect provides a method of exposing a plurality of thin printing plates frorn a single stationarily mounted film negative, comprising stacking a plurality of thin plates with their emulsion surface facing downwardly in an accurately located position, making vacuum connection to the back surface of the uppermost thin plate of the said stack, moving the said uppermost thin plate to place its emulsion side surface into contact with the said film negative, exposing the emulsion side surface of the said plate through the said negative, making vacuum connection to the back surface of the plate after its exposure and removing the plate from the film negative, depositing the plate on a plate belt carrier with the emulsion side facing upwardly, delivering the plate to a photoprocessor for developing the plate, and thereafter making connection to the next uppermost thin plate of the stack, and moving the said next uppermost plate through the same sequence.

The first major component of a preferred embodiment of a plate making system according to the invention is a film negative carrier and negative exposure lamp means.

The film negative carrier comprises a sliding drawer having locating pins for locating a negative in an exact position on the drawer and a vacuum system to ensure that the negative will be snugly held. A high intensity exposure lamp means, which contains an ultraviolet lamp or lamps, is disposed beneath the sliding drawer and is in position to illuminate the negative and any photosensitive plate above the negative at an automatically controlled time and after a photosensitized plate has been placed on top of the negative. The negative support drawer is slidable to an outer position to where a negative can be secured to the drawer and the drawer can then slide into an accurately located position in the apparatus relative to the exposure lamp. The operator may select a suitable automatic exposure time for the exposure system, for example 3 seconds, and the film change can be made in about 13 seconds.

The next major component of the preferred plate making system is a plate supply arrangement wherein a stack of aluminium plates with photosensitive emulsion on one surface are provided with their photosensitive side facing downwardly so that the plates can be individually gripped on their upper and unsensitized surface without damaging the emulsion.

The plate stack may be carried on a tray which can be loaded into an adjustable height plate feeding system which may be controlled so that the top of the uppermost plate is accurately controlled in height and may be jogged against three adjustment stops for accurate pre-registered positioning.

The uppermost plate of the stack can be sensed by a suitable photosensing device which is accurate to less than the thickness of the relatively thin plate. The upper surface of the plate is then gripped by a parallelogram supported plate to move the plate from its accurately pre-registered position into accurate registry with the film negative.

The next major component of the pre ferrëd system is a vacuum plate which moves the uppermost plate from the plate stack to the negative. The vacuum plate is carried by a parallelogram mechanism wherein the vacuum plate engages the top of the stack of plates, picks up the uppermost plate of the stack, and holds the uppermost plate in an exactly aligned position relative to the system frame by virtue of the exact alignment of the uppermost plate of the stack. The parallelogram mechanism then moves the vacuum plate and the photosensitized plate to a location immediately above the top of the film negative on the film negative drawer. Guide openings in the vacuum plate mating with pins on the negative frame ensure the accurate location of the photosensitive plate on the film negative, with its photosensitive side facing down. A vacuum is actuated in order to hold the aluminium plate surface firmly against the negative surface and to hold the vacuum plate on the film drawer support surface, and an - exposure is made by the energization of high intensity lamps beneath the negative.

The parallelogram plate carrier is then moved away and toward the plate stack and toward a position where it can pick up the next plate of the stack.

A further major subassembly of the preferred system which then comes into operation is a transfer arm mechanism which engages the top of the exposed plate with spaced vacuum cups, and then moves the exposed plate and inverts it onto a set of power driven delivery belts which feed the exposed plate, with its exposed side up, into a conventional plate processor. Once the transfer arm mechanism has removed the plate from the film negative drawer, a new cycle begins and a second plate is delivered, by the parallelogram mechanism, to the film negative drawer for a new exposure.

In the particular embodiment of the invention to be described herein, there is an approximately 20 second operating cycle for processing a single plate and about 3 plates per minute can be exposed and delivered to the plate processing unit in an automated manner and without operator attention. Up to 500 plates can be loaded and additional plates can be loaded without causing any substantial downtime. Moreover, the unit is compact and self-contained and can be operated by personnel with relatively little training.

Important features of the apparatus of the present invention are that, during the entire operating cycle, the plate is handled from its non-emulsion side and the plate is kept under positive control until it is fed into the photoprocessing unit. Suitable controls for operating the equipment may be adjusted to produce a given number of copies, whereupon the negative carrier, or the film frame, is automatically moved out to a loading position. The vacuum holding the film on the frame is released, and the operator can remove the film from its register pins and attach a new negative to the drawer. The frame is then returned to its exposure position with the new negative in place.

The invention will be further described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a schematic plan view of the apparatus of the present invention with a covering.shroud therefor removed; Figure la is a perspective view of the assembled apparatus of the present invention with a covering shroud in place; Figure 2 is an elevation view of the front of Figure 1; Figure 3 is an elevation view bf the righthand end of Figure 1; Figure 4 is a cross-sectional view illustrating an aluminium plate in position within a film drawer for making an exposure; Figure 5a is a plan view of the plate supply subassembly of a specific embodiment of the present invention; Figure 5b is an elevation view of the lefthand end of Figure 5a; Figure Sc is an elevation view of the front of Figure 5a; Figure 6a is a plan view of the film negative drawer of the embodimrent of the present invention shown in Figure 5; Figure 6b is a partial cross-section and partial elevation view of the front of the film drawer of Figure 6a; Figure 7a is a plan view of the film carrying plate and parallelogram mechanism of the embodiment of the present invention shown in Figures 5 and 6; Figure 7b is an elevation view and partial cross-sectional view of the front of Figure 7a; Figure 8a is a plan view of the transfer arm assembly of the embodiment of the present invention shown in Figures 5 to 7 with the transfer arm in position for picking up a plate from the film drawer; Figure 8b is a side view of the pivotal latch mechanism for one of the arms of Figure 8a; Figure Sc is an elevation view of the rear of the assembly of Figure 8a; Figure 8d is a diagram showing the operating linkage for the transfer arms in various position of its operation cycle; Figure 8e is an elevation view of the transfer arm assembly and illustrates the latching action of the transfer arm assembly; Figure 8f is a partial view of Figure 8e taken across the section lines 8f-8f in Figure 8e; Figure 8g is a view of Figure 8e taken across the section lines 8g-8g in Figure 8e; Figure 8h is a view of Figure 8e taken across the section lines 8h-8h in Figure 8e, and particularly illustrates the spring connection between the latch member and one of the separable transfer arm links.

Figure 9a is an elevation view of the side of the delivery belt system of a specific embodiment of the apparatus of the present invention; and Figure 9b is a plan view of the delivery belt arrangement of the apparatus of the present invention.

Referring first to Figure lea, there is shown a film drawer 31 moved outwardly to-the position where an operator can load a film negative on top. of a glass plate 32 and- over positioning -pins 190 and 191. The film drawer 31 in Figure la is about waist high or 30 inches above floor level, and may be placed between work material support ta-bles,5such as tables 40. A suitable con trol panel- 41-a may also be provided as illustraded and will contain controls for setting copy numbers, and for programming the machine operation, and will also contain manual over-ride controls and operation indicators. The left-hand side of Figure la has a stack 41 of aluminium plates, which are loaded with their emulsion surface facing downwardly. The stack 41 is carried on a suitable carrier 42 which can move the stack 41 into the apparatus over a roller conveyor 43.

Plates which have been automatically exposed are delivered with the emulsion side facing upwardly on delivery belts such as belts 449, 450, 452 and 453 disposed at the rear of the equipment. A suitable plate processor, which may be of any standard commercially available type, and which is adapted to receive exposed aluminium plates with their emulsion side facing upwardly, then receives the output plate from the belts 449 to 453.

Figure 2 illustrates the stack of plates 41 - which might contain as many as 500 plates, where the stack 41 and its carrier 42 are schematically illustrated as being movable upwardly or downwardly under the influence of a motor, and are guided in bearings 50 and 51. The control motor is operated in order to place the topmost aluminium plate at a given vertical position which is determined by a suitable stack height monitor 52, which can be a photoelectric cell system, to ensure that the plate moving equipment will register properly with the topmost aluminium plate. In addition, a suitable pick-up and jogger assembly will be provided to separate the--upper- most plate from the stack and to force at least the uppermost plate of the stack 41 against three spaced stops to ensure that the plate has an exactly fixed position relative to the support frame. Thus, when the uppermost plate is picked up and moved to the film negative, it will be also accurately located relative to the film negative.

The film drawer 31 of Figure la is also seen in Figures 1, 2 and 3 in the retracted position for loading a negative on the drawer. The film drawer 31 is mounted on rails, which will be later described in more detail, to enable the film drawer 31 to move upwardly in Figure 1 and to the right in Figure 3 to place the film drawer immediately above an exposure lamp system 60.

The exposure lamp system 60 may also be mounted on rails to allow access to the lamps, the reflector, and the lamp cooling system.

When the film drawer 31 is in its outward position, the operator places a film negative on top of the glass plate 32, with the negative being aligned relative to. the drawer 31- by having preformed openings fitted over the positioning pins 190 and 191.

A vacuum system (not shown in Figures 1-to 3) is also provided to exhaust all of the air between the negative and the glass plate 32, to ensure that the negative will be snugly held on top of the film drawer 31.

An operator with relatively little training will be able to remove the previous negative and install a new negative and then close the drawer in about 13 seconds. The drawer 31 may be moved between its open and closed positions by suitable automatic operating controls which can be operated or pre-set from the control panel 41a.

Accurate positioning of the film drawer 31, when closed, is ensured by a suitable tray stop 70 which may have a permanent magnet fixed thereto which seals against the drawer 31 when it is closed. In addition, a V-block arrangement, which is located by a hardened pin arrangement, may also be used. Once the film drawer 31 is closed against the stop 70 in Figure 1 and is disposed above the lamp system 60, one of the aluminium plates from the top of the stack 41 is to be deposited with its photosensitive surface facing downwardly on top of the negative, on top of the glass plate 32, and accurately located relative to the negative on the glass plate.

The lamp system 60 consists of a suitable elongate lamp 61 contained within a suitable reflector 62 and is operable to direct intense light upwardly toward the film drawer 31 to expose the photosensitive surface of an aluminium plate on top of the film negative on the glass plate 32 of the film drawer 31.

In order to move the topmost plate from the stack 41 onto the negative on the closed film drawer 31, a parallelogram mechanism is provided which contains parallel identical arms 71 to 74. The arms 71 to 74 have their lower ends pivotally mounted on the support frame of the apparatus and have their upper ends pivotally mounted to the corners of a carrier plate 75. A suitable drive motor 76 is connected to the parallelogram linkage in order to operate the linkage through a suitable control circuit. In addition, suitable counterbalance springs can be mounted on stationary posts, and can be connected to the parallel link arms 71 to 74 in order to at least partly support the weight of the plate 75 during its operation, thus relieving the load somewhat from the operating motor 76. Alternatively, a moving carriage and cable reel spring arrangement could be used.

A typical counterbalance spring 77 is shown in Figure 2 connected to a post 78 which is fixed to the main support frame.

The plate 75 as shown in Figure 2 is provided with vacuum line connections which are flexible, shown as flexible vacuum lines 80, 81 and 82, which are connected to small outlet openings in the bottom of the plate 75. These hose nipple connections are schematically shown in Figure 1 for vacuum openings 83, 85, 86 to 91, and 93. Openings 84 and 92 in the plate 75 receive alignment pins 100 and 101 on the drawer 31, as will be later described.

The parallelogram linkage will now operate such that the plate 75 moves from a position directly on top of the stack 41 to a position directly on top of the film drawer 31 for transporting plates from the top of the stack 41 to the film drawer without inverting the plates. Thus, the plate 75 moves with parallel motion, to engage the top of the stack 41. When the plate 75 rests on the stack 41, vacuum is applied to vacuum openings 86, 87, 88, 89 and 90 so that the uppermost plate of the stack 41 will adhere to the bottom of the plate 75. The uppermost plate of the stack 41 and the plate 75 linkage is operated to rotate in a clockwise direction in Figure 2. The uppermost plate of the stack 41 is extremely accurately located relative to the machine frame so that it will also be accurately located on the plate 75.

The plate 75 and the aluminium plate secured thereto is then deposited immediately on top of the glass plate 32 and in registry with the film negative which is secured thereto. This position is shown in Figure 4, which schematically illustrates the plate 75 as it comes downwardly on top of the film drawer 31. In Figure 4 the film drawer 31 is carried on a fixed drawer track arrangement and the film drawer 31 is held against stops, such as stops 70, shown in Figure 1. The film negative is shown in Figure 4 as located on the pins 190 and 191 and the uppermost aluminium plate 95 of the stack 41 is shown as adhering to the bottom surface of the plate 75 by virtue of vacuum which has been applied to the openings 86 to 90 in the plate 75. The plate 95 is extremely accurately located relative to the film negative on top of the plate 32 by virtue of extreme accuracy in positioning the plate 95 on the top of the stack before it is picked up by the plate 75.

The bottom surface of the plate 75, as is best shown in Figure 4, is provided with a gasket 96 which seats around and is outside of the periphery of the film negative and seals against the upper surface of the film drawer 31 .,As the plate 75 comes down on top of the film drawer 31, it and thus the plate 95 are accurately located relative to the film drawer by virtue of locating pins ]00 and 101 on the film drawer which enter openings 84 and 92, respectively, in the plate 75. After the plate 95 is seated against the negative, vacuum is applied to the openings 83, 85, 91 and 93 in the plate 75 to eliminate any possible air film between the aluminium plate 95 and the film negative.

The exposure lamp system 60 is then operated to produce an intense light which passes through the glass plate 32 and the film negative to expose the downwardly facing emulsion on the plate 95. The exposure lasts about 3 seconds and, when complete, positive pressure is applied to the hoses connected to the openings 83, 85 to 91, and 93. This removes the plate 95 from the plate 75 so that, when the plate 75 is moved, the exposed plate 95 will remain on top of the film negative.

The parallelogram linkage then operates to return the plate 75 to the position shown in Figure 2, in order to pick up the next uppermost plate of the stack 41. The stack 41 is operated through its operating motor, guided by the bearings 50 and 51 so that the next uppermost plate is moved upwardly until stopped by the stack height monitor 52. In an actual embodiment of the invention, a single motor, operating through a jack, is used and the stack is guided for motion by suitable guide rods.

It is now necessary to move the exposed plate 95 of Figure 4 from the film drawer 31. This operation is performed by a transfer system which grips the plate through vacuum means on its upper surface and then inverts the plate to move it to a suitable delivery belt which will deliver the plate, emulsion side up, into a suitable photoprocessor.

The vacuum transfer system is schematically illustrated in Figures 1, 2 and 3 and consists of a transfer vacuum frame having arms 110, 111 and 112. The arm 110 has vacuum cups 113 and 114, the arm 111 has a vacuum cup 115, and the arm 112 has vacuum cups 116 and 117. A suitable vacuum supply is connected to the cups 113 to 117 through tubes in the arms 110, 111 and 112. All of the vacuum cups 113 to 117 are fixed in a common plane and move, as a single body, with the rotation of pivotal support arms 120, 121 and 122.

The support arms 120, 121 and 122 are mounted on a common pivotal support shaft 306, as best seen in Figure 8a. The entire transfer vacuum assembly is then rotatable about the pivotal support shaft 306, such that the vacuum cups 113 to 117 can rotate from a retracted position, in which the cups face upwardly and are disposed in a generally horizontal plane, to an operating position in which they are rotated counterclockwise about the pivotal support shaft 306 to - face downwardly and engage the upper back- surface of plates, such as the plate 95, lying on top of the film drawer 31.

When the vacuum cups 113 to 117 are rotated to pick up an exposed aluminium plate, they engage the exposed aluminium plate on its upper unsensitized surface.

Once the parallelogram linkage has moved the plate 75 out of position, a suitable operating control operates a motor 124 shown in Figure 3 to move the vacuum transfer arms counterclockwise such that the cups 113 to 117 will engage the rear surface of the plate on the drawer 31. A vacuum is then drawn in the cups 113 to 117 to cause them to adhere to the rear surface of the plate. Thereafter, the motor 124 is energized to cause the entire frame to rotQe clockwise about the pivoted support shaft 306 in Figure 3, to move the plate out of the film drawer and also to invert the plate so that its photo-emulsive side faces upwardly. As the transfer frame continues to rotate clockwise in Figure 3, the arms 110, 111 and 112 pass through and between delivery belts. The vacuum holding the plate to the frame is released as the belts are reached, and the plate is deposited on top of the belt for delivery to a suitable processor.

The delivery belt system is shown in Figures 1 and 3 as consisting of two sets of belts which operate at different speeds.

Thus, there is a first set of belts 415 to 418, which are each continuous belts rotating in a direction such that their top surface moves away from the film drawer 31 and toward a photoprocessor discharge region.

These belts 415 to 418 move essentially in the same plane as the second set of belts 449 to 453 which were previously described in connection with Figure la. The belts 415 to 418 move at a relatively high speed in order to move plates away from the region of the transfer arms as quickly as possible to permit the early recycling of the apparatus. The belts 449 to 453 move at a lower speed, and at a speed determined by the photoprocessor. Once the plate has been moved on top of the belts which deliver the plate to the photoprocessor, the parallelogram linkage can move the plate 75 to deposit a new plate on the drawer 31.

Figures 5 to 9 illustrate a specific preferred embodiment of the apparatus of the invention.

Referring first to Figures Sa, 5b and 5c, there is shown a specific arrangement which can be used for the plate supply for supporting the plate stack 41. Figures 5a and Sc show a support tray 42 which can be raised and lowered by a suitable worm-drive motor 139 which drives a shaft 140 connected to the tray 42. The support tray 42 carries a plurality of parallel rollers 43 to assist in the loading of the stack 41. The plate stack 41 is shown as disposed on top of rollers 43. Suitable stabilizer shafts 141 and 142, which are slidable in suitable bearings, prevent the tray 42 from tilting as it moves up and down.

Three adjustable stops are provided adjacent the stack 41 including adjustable side-stop position members 150, 151 and 152 which permit the accurate positioning of the uppermost plate of the stack 41 relative to the support apparatus. The stops 150, 151 and 152 are resiliently biased above the level of the uppermost plate of the stack 41.

A jogging means is provided for jogging the stack 41 against the stops 150, 151 and 52. The jogging mechanism is shown schem- atically in Figures 1 and 2 and comprises a vacuum cup 154a mounted on a sliding arm 155 which is rotatably attached to a support frame 162 by a pivotal arm 156. A suitable vacuum connection (not shown) is connected to the cup 154a. A vibrating solenoid (not shown) may also be connected to the cup to help separate the upper plate from the stack 41. The jogging mechanism operates after the stack 41 has moved to its desired height, and the arm 156 moves from the dotted-line position in Figure 1 to its solid-line position, and the arm 155 then moves down so that the cup 154a engages the upper plate of the stack. A vacuum is drawn in the cup 154a and the arm 155 is slightly raised to raise the corner of the uppermost plate, and the arm 156 is rotated counterclockwise in Figure 1 to move the uppermost plate slightly off the stack 41 and into engagement with the three positioning stops 150, 151 and 152 (Figure spa). The cup 154a then releases the uppermost plate and retracts to its dotted-line position in Figure 1.

Figures 5a and Sc further illustrate the placement of a photosensing mechanism which is operable to sense the position of the top of the stack 41 and to deliver an output signal to the control mechanism so that the operating motors which raise the stack are appropriately controlled. Thus, a lamp 158 and photosensor 159 are mounted adjacent a corner of the stack 41, and monitor the presence or absence of an uppermost sheet of the stack 41 at their level.

The output of the photosensor 159 then controls the motor 139 through an approp riate control circuit. The lamp 158 and photosensor 159 can be mounted in any other desired manner.

All of the components described above in connection with Figures 5a, 5b and Sc are supported from a common support frame consisting of welded or bolted tubular members which are made of a suitable structural steel.

Figures 6a and 6b illustrate the negative film drawer 31. Referring to Figures 6a and b, the top of the drawer. 31 is held about 30 inches from the floor by tubular frame members 160, 161,162 and 163. The frame member 161 has a U-shaped rail 170 clamped thereto while the frame member 160 has spaced rod support members, such as a member 171, extending therefrom which support a guide rod 173 between them. The film drawer 31 is then provided with a rotatable wheel 175 which rides on the rail 170 and is also provided with receiving members 176 and 177 which are slidably mounted on the rod 173. Thus, the drawer 31 is slidably mounted on the main support frame so that it can be moved from the position shown in Figure la, where it is exposed for use by an operator, to the closed position where an exposure can be made of an aluminium plate carried on -the drawer.

Figure 6a further illustrates the glass table 32 supported within a suitable glass mount opening 180 which may be about 1/32 of an inch greater in dimension than that of the glass.

Figures 6a and 6b further illustrate the film locating pins 190 and 191 and also the pins 100 and 101 for locating the plate 75 on top - of the film drawer when the plate 75 moves into position as was described in connection with Figure 4.

Figure 6a illustrates, in dot-dashed lines, the boundary of the film negative, and the nected to flexible vacuum hoses 230 to 239, respectively.

Figure 7a further shows the pivotal connection of the arms 71 and 72 to the support frame members 163 and 162, respectively, at pivots 250 and 251, respectively.

Similar pivotal supports are provided for the parallelogram arms 73 and 74 which have a length identical to that of arms 71 and 72.

Any desired counterbalance can be used to balance the weight of the plate 75. Figure 7a shows one type of counterbalance which includes a counterbalance spring 255 which has one end thereof connected to a spring connection end 256 of the arm 71. A similar counterbalance spring arrangement can be provided for each of the parallelogram arms. However, other counterbalance arrangements could be used.

Also illustrated in Figures 7a and 7b are the positioning openings 84 and 92 in the plate 75 which register with the pins 100 and 101 on the drawer 31. In order to ensure registration between the plate 75 and the top aluminium plate of the stack 41, when the plate is picked up, the surface 260 of the stack support assembly in Figure 7b contains positioning pins 261 and 262 which receive the openings 84 and 92. This ensures that the plate 75 will settle in the precisely correct location on top of the stack 41 before the uppermost plate of the stack 41 is picked up with the application of vacuum to the hoses 233, 234, 235, 236 and 237.

After the plate 75 picks up the uppermost plate of the stack 41, which has been exactly located within the stack, it moves to the film drawer 31 to deposit the plate on top of the film drawer as previously discussed. Once the plate 75 settles on top of the film drawer 31, vacuum is applied to the hoses 230, 231, 238 and 239 in order to remove any air which might be trapped between the film negative and the aluminium plate carried by the plate 75. After the aluminium plate has been exposed in the position of Figures 6a and 6b, positive pressure is applied to all of the hoses 230 to 239 so that the plate 75 can move away and leave the exposed aluminium plate behind on the film drawer 31. In order to ensure that a good vacuum is drawn between the plate 75 and the film drawer 31, a seal 96 (see Figure 4) is formed around the bottom surface of the plate 75 and this seal will seal against the upper surface of - the film drawer 31.

Figures 8a to 8d 'show the various components which are used to form a transfer arm assembly of a type slightly different from that schematically illustrated in Figtires 1, 2 and 3. In the preferred embodiment, the transfer arms pick up exposed plates, from the film drawer 31, and then deposit the exposed plates with their emulsion side facing upward, at a level higher than the drawer level, and then drop below the belts after depositing the plate on the belts.

Referring to Figure 8a, the arms 110, 111 and 112 (see Figure 1) are shown overlying the film drawer 31 and in position to pick up an exposed aluminium plate from the top of the drawer 31. Each of the arms 110, 111 and 112 contain the various vacuum cups 113 to 117 which are connected to a suitable vacuum supply through tubes in the arms 110, 111 and 112. The cups 113 to 117 are coplanar and, when they contact the back surface of an exposed aluminium plate, they are coplanar with its surface and the film drawer 31.

Each of the arms 110, 111 and 112 is then rigidly connected to a cross-brace member 300 which has a hollow tube extending therethrough connected to a fitting 301 to allow the connection of a flexible vacuum conduit to the arms 110, 111 and 112 and their respective vacuum cups. Two identical circular arms 302 and 303 then have one of their ends pivotally connected to the member 300 at pivots 304 and 305, respectively, as shown in Figure 8a.

The shape of the arm 303 is best shown in Figure 8d where the arm 303 is shown in five positions labelled 1 through 5 showing the sequence of operation of the transfer system. The positions 1, 2 and 3 also show different heights of the belts from floor level to -accommodate different style photoprocessors.

The arms 302 and 303 are then rotatably mounted relative to and on the shaft 306, which is rotatably supported in brackets 307 and 308 as shown in Figure 8c. As will be later described, the arms 302 and 303 are driven by driver arms 302a and 303a which are connected to the shaft 306 and are rotated by the latter.

Brackets 307 and 308 are suitably supported by a frame member 311 as best seen in Figure which is a rear view of the transfer arm assembly. The shaft 306 is rotatably driven by a motor 309 shown in Figure Sc which is connected to the shaft 306 by a belt 310. The motor 309 is then controlled in any suitable manner from a control circuit.

The shaft 306 also carries a central arcuate connection link 320 which rotates with the arms 302 and 303 and is shown in the five different positions labelled 1 to 5 in Figure 8d, which corresponds to the same labelled positions of the arm 303.

The outer end of the arcuate link 320 is pivotally connected to a second link 321 as shown in Figures 8a, -8b and 8c, where a pivotal connection 322 is a latchable pivot arranged such thåt the links 320 and 321 can straighten out as they rotate from position number 1 to position number 4 but will remain in a straight line relative to one another as shown in positions 4 and 5.

The outer end of the link 321 is then pivotally connected, by a pivot 330, to a connecting rod 331 which is rigidly connected to the arm 111.

The pivot 322 is best shown in Figures 8a and 8b and includes a spring 340a which tends normally to hold the links 320 and 321 in the straightened condition shown in Figure Sb where the link 321 rests against an interior shoulder 341.

A latchable connection is provided between the driver arms 302a and 303a and their arcuate arms 302 and 303, respectively, as is best shown in Figures 8e and 8h. Each of the arms 302a and 303a has an angle plate 340 and 341, respectively, bolted thereto which serves to allow the arms 302 and 302a to engage one another and move together from the position number 5 in Figure 8e to the position number 2 in Figure 8e. The arms 302a and 302 are latched together by a latch member 342 which is pivotally mounted on the arm 302 by a pivot pin 343. The latch member 342 carries a latch projection 344 at one end and a spring 345 at its other end. A cam roller 346 is also carried at the one end of the latch member 342. The spring 345 is fixed to the arm 302a and tends to rotate the latch 342 counterclockwise in Figure 8e.

An angle plate 340 on the arm 302 has an upwardly extending portion 350 which receives one end of a spring 351. The other end of the spring 351 is connected to the angle plate 341, thereby tending to hold arms the 302 and 302a together in the position shown. The latch projection 344 is latched over a latching surface 352a of the angle plate 340, to latch the two arms together, and to ensure that they rotate together until the latch is undone.

A fixed cam 352 is attached to the frame member 311 and is located such that, when the arms 302 and 302a reach position number 2 (in solid lines for the latch member 342), the roller 346 is pressed to the right to move the latch projection 344 out of latching relation to the angle plate 340. The arm 302 then engages a stop (not shown) and stops in position number 1, but the arm 302a continues to rotate (counterclockwise in Figure 8e) until it hits a stop 360.

During the continued rotation of the shaft 306, after the arm 302 has stopped rotating, the arms 110, 111, 112 continue to rotate due to continued motion of the link 320. However, the continued rotation will now be around the axis of the member 300 (since the arms 302 and 303 are stationary) so that the arms 110, 111 and 112 can come to rest in a plane paallel to but above the plane they assume when they pick up a plate from the film negative drawer.

When the arms 302 and 302a now rotate away from their stop positions in Figure 8e, the springs 345 and 351 will reset the latch between them and they will move together to position number 5 in Figure 8e.

The operation of the transfer arm arrangement can also be understood from Figangement can also be undestood from Figure 8d which shows the arms 111 and 112 in various operating position. In the initial retracted position number 1 of Figure 8d, the arms 111 and 112 are retracted below the level of the plate receiving belts which will be later described. This level is vertically above the level of the plate which is to be removed from the drawer 31, which is position number 5 for the arms 111 and 112.

The transfer arm construction permits rotation of the arms 111 and 112 (as well as the arm 110) from position number 1 to position number 5 and plate pickup occurs when the cups 113 to 117 engage the back of the plate to be transferred. A vaccum is then applied to the various vacuum cups 113 to 117 and the transfer arms are then rotated from position 5 to position number 1. During this rotation, the plate will be inverted so that it has been grasped on its non-emulsion side at position number 1 and, as the transfer arms rotate to position number 5, the plate is inverted with its emulsion up, and is deposited on the belts. The vacuum on the cups 113 to 117 is broken just before the belt position is reached. The arms 110 to 112 continue to rotate, and finally retract beneath the level of the belts. The latching arrangement described above permits the transfer arms to rotate from a first horizontal position to an inverted but higher horizontal position by causing the the link 320 to break when the transfer arms move away from the film drawer position number 5.

The delivery belt or take-off system is best shown in Figures 9a and 9b in connection with the plate transfer assembly of Figures 8a through 8d. In Figures 9a and 9b, the take-off system is shown as being supported within side frame members 400 and 401 which rotatably receive roller conveyor belt support members in the form of pulleys 402 to 405.

The frame member 400 and 401 also pivotally receive a rotatable shaft 410 which carries roller drive members 411 to 414. Suitable endless flexible belts 415 to 418, respectively, are mounted between pulleys 402-411, 403-412, 404-413, and 405414. A suitable drive motor 430 (Figure 9a) drives a shaft 431 which has a drive belt 432 connected thereto which drives a pul ley 433 mounted on the left-hand end of the shaft 410 as shown in Figure 9b, in order to rotatably drive the shaft 410.

A second shaft 440 is rotatably mounted between the frame members 400 and 401 in Figure 9b and contains a plurality of drive pulleys 441 to 444 which are connected to wheels 445 to 448, respectively, on the shaft 410 by the belts 449 to 453, respectively. A drive belt connection is then made from a pulley 460 on the shaft 410 to a pulley 461a on the shaft 440 by a drive belt 462a.

In operation, the upper surfaces of all of drive belts 415 to 418 and 449 to 453 are driven to the right in Figure 9a, and downward in Figure 9b, and toward the discharge end of the apparatus which contains a conventional photoprocessor which will receive plates from the belts with their emulsion side facing upwardly. As the transfer arms 110, 111 and 112 move downwardly between the belts 415 to 418 as shown in Figure 9b, vacuum is released at the vacuum cups 113 to 117 and the plate carried by the transfer arms is- deposited on top of the belts 415 to 418. These belts then move the plate onto faster moving belts 449 to 453 which ultimately discharge the plate 95 from -the equipment.

The belts 449 to 453 will move at a speed determined by the rate at which plates are to be supplied to the plate processor. The belts -415 to 418, however, are higher speed belts to remove plates from interfering with the return motion of the transfer arm assembly.

It will be noted that the belts 449 to 453 travel over respective pulleys 460a, 461, 462 and 463 which are rotatably carried on a support shaft 470 and are adjusted to press upwardly against the belts 449 to 453 to apply suitable tension to the belts. The pulleys 460a, 461, 462 and 463 are then fixed in the desired adjustment position by any suitable locking mechanism.

WHAT WE CLAIM IS: 1. A plate making system comprising support means for supporting a stack of aluminium photographic plates with their emulsion side facing downward, a film negative carrier for supporting a film negative in accurate registry with the said stack the said film negative carrier having an upper surface at about the samle height as the top of the stack, plate exposure lamp means disposed beneath the film negative carrier for exposing plates disposed on top of the film negative carrier through a negative fastened thereon, first transfer means adapted to contact the back surface of the uppermost plate of the said stack of plates and to move the said uppermost plate, with its emulsion surface facing downward, onto the film negative carrier, second transfer means adapted to contact the back surface of a plate on the film negative carrier and to move the said plate, and invert it to have its emulsion side facing upwardly, and to deposit the plate onto an output means for delivering an exposed plate from the said system, with its emulsion side facing upward, to a photo-processing unit for developing the plate.

2. A plate making system as claimed in Claim 1, wherein the first transfer means includes a flat carrier plate and a parallelogram linkage for supporting the carrier plate for moving the said uppermost plate with parallel translational motion from the top of the said stack to the top of the film negative carrier.

3. A plate making system as claimed in Claim 2, which further includes first registry means on the carrier plate, second registry means on the said stack support means and third registry means on the film negative carrier, the first registry means cooperating with both of the second and third registry means when the carrier plate engages the said stack and the film negative carrier respectively to ensure registry of the plate of the stack carried by the carrier plate wth the film negative carrier.

4. A plate making system as claimed in Claim 2 or 3, further comprising vacuum connection means connected to the carrier plate to permit a vacuum connection between the bottom of the said plate and the uppermost plate of the stack.

5. A plate making system as claimed in any of Claims 1 to 4, further comprising stop means for accurately locating at least the top of the said stack before the first transfer means engages the uppermost plate of the stack.

6. A plate making system as claimed in any of Claims 1 to 5, further comprising slide support means for supporting the film negative carrier, the film negative carrier being slideable from an open position where an operator can secure a film negative to the carrier to a closed position where the film negative is disposed above the said plate exposure lamp means.

7. A plate making system as claimed in any of Claims 1 to 6, further comprising stack raising means for automatically moving the top of the said stack to a predetermined height.

8. A plate making system as claimed in any of Claims 1 to 7, wherein the said output means comprises conveyor belt means.

9. A plate making system as claimed in Claim 8, wherein the said conveyor belt means comprises a plurality of parallel spaced belts disposed at about the level of the said film negative carrier, the upper surface of the said plurality of belts being in a plane generally parallel to the plane of the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. ley 433 mounted on the left-hand end of the shaft 410 as shown in Figure 9b, in order to rotatably drive the shaft 410. A second shaft 440 is rotatably mounted between the frame members 400 and 401 in Figure 9b and contains a plurality of drive pulleys 441 to 444 which are connected to wheels 445 to 448, respectively, on the shaft 410 by the belts 449 to 453, respectively. A drive belt connection is then made from a pulley 460 on the shaft 410 to a pulley 461a on the shaft 440 by a drive belt 462a. In operation, the upper surfaces of all of drive belts 415 to 418 and 449 to 453 are driven to the right in Figure 9a, and downward in Figure 9b, and toward the discharge end of the apparatus which contains a conventional photoprocessor which will receive plates from the belts with their emulsion side facing upwardly. As the transfer arms 110, 111 and 112 move downwardly between the belts 415 to 418 as shown in Figure 9b, vacuum is released at the vacuum cups 113 to 117 and the plate carried by the transfer arms is- deposited on top of the belts 415 to 418. These belts then move the plate onto faster moving belts 449 to 453 which ultimately discharge the plate 95 from -the equipment. The belts 449 to 453 will move at a speed determined by the rate at which plates are to be supplied to the plate processor. The belts -415 to 418, however, are higher speed belts to remove plates from interfering with the return motion of the transfer arm assembly. It will be noted that the belts 449 to 453 travel over respective pulleys 460a, 461, 462 and 463 which are rotatably carried on a support shaft 470 and are adjusted to press upwardly against the belts 449 to 453 to apply suitable tension to the belts. The pulleys 460a, 461, 462 and 463 are then fixed in the desired adjustment position by any suitable locking mechanism. WHAT WE CLAIM IS:

1. A plate making system comprising support means for supporting a stack of aluminium photographic plates with their emulsion side facing downward, a film negative carrier for supporting a film negative in accurate registry with the said stack the said film negative carrier having an upper surface at about the samle height as the top of the stack, plate exposure lamp means disposed beneath the film negative carrier for exposing plates disposed on top of the film negative carrier through a negative fastened thereon, first transfer means adapted to contact the back surface of the uppermost plate of the said stack of plates and to move the said uppermost plate, with its emulsion surface facing downward, onto the film negative carrier, second transfer means adapted to contact the back surface of a plate on the film negative carrier and to move the said plate, and invert it to have its emulsion side facing upwardly, and to deposit the plate onto an output means for delivering an exposed plate from the said system, with its emulsion side facing upward, to a photo-processing unit for developing the plate.

film negative carrier, and wherein the upper surface of the said belts moves away from the film negative carrier.

10. A plate making system as claimed in Claim 9, wherein the second transfer means is adapted to move between the said belts and below the uppper surface of the belts after a plate is deposited on the belts.

11. A plate making system as claimed in Claim 9 or 10, wherein the said plurality of spaced belts comprises first and second sets of belts which are longitudinally displaced from one another.

12. A plate making system as claimed in any of Claims 1 to 11, wherein the second transfer means comprises a transfer arm assembly, means for rotatably mounting the transfer arm assembly, and vacuum pickup means mounted on one surface of the transfer arm assembly, the vacuum pickup means being engageable with the back surface of a plate on the film negative carrier and being operable to pick up a plate thereon, and the transfer arm assembly being rotatable to invert the plate and deposit it emulsion-side facing upwardly on the said output means, and thereafter having the vacuum pick-up means move below the upper surface of the output means.

13. A plate making system, substantially as herein described with reference to, and as shown in, the accompanying drawings.

14. A method of exposing a plurality of thin printing plates from a single stationarily mounted film negative, comprising stacking a plurality of thin plates with their emulsion surface facing downwardly in an accurately located position, making vacuum connection to the back surface of the uppermost thin plate of the said stack, moving the said uppermost thin plate to place its emulsion side surface into contact with the said film negative, exposing the emulsion side surface of the said plate through the said negative, making vacuum connection to the back surface of the plate after its exposure and removing the plate from the film negative, depositing the plate on a plate belt carrier with the emulsion side facing upwardly, delivering the plate to a photoprocessor for developing the plate, and thereafter making connection to the next uppermost thin plate of the stack, and moving the said next uppermost plate through the same sequence.

15. A method as claimed in Claim 14, wherein the said plate is in a horizontal plane when located on top of the stack, and when located on top of the film negative, and when located on top of the plate belt carrier.

16. A method as claimed in Claim 14 or 15, further comprising mounting the film negative on a sliding drawer support, and thereafter sliding the drawer support into exposure making position.

17. A method as claimed in any of Claims 14 to 16, wherein the said thin plate is moved with parallel translational motion when moving from the stack to the film negative.

18. A method of exposing a plurality of thin printing plates from a single stationarily mounted film negative, substantially as herein described with reference to the accompanying drawings.