Patent Application
20080150223
A system for removing and/or separating an interleaf sheet from a plate sheet and/or transporting a plate sheet that is used in conjunction with, e.g., a Computer-to-Plate imaging system.
Published United States patent application US 2006/0117975 relates generally to a system and method for removing and/or separating an interleaf sheet from a plate sheet and/or transporting a plate sheet, used in connection with, for example, Computer-to-Plate (CTP) imaging systems. As is described in paragraph 0005 of such published patent application, “Automating the printing process in CTP imaging systems involves the alternating process of extracting plate sheet material, and then interleaf sheet material, from a material stack. Images are exposed on the plate sheet material, and the interleaf sheet material is used to protect the imaging surface of plate sheets from each other.”
In paragraph 0007 of such patent application, it is disclosed that “Extracting the interleaf sheets manually is labor intensive, but normally does not present other issues or challenges. However, automating the process for extracting interleaf sheets can be challenging. For example, interleaf sheets can adhere onto the imaging surface of the plate sheet because of, for example, friction and/or static. Known CTP systems that automate the removal of interleaf sheets, such as disclosed in U.S. Pat. No. 5,655,452, which is in incorporated herein by reference, use at least a combination of a suction cup and air blast. However, due to the porous nature of the interleaf sheet, reliability issues are generally present when suction cups are used to remove interleaf sheets.”
Claim 1 of published patent application US 2006/0117975 discusses a system for removing an interleaf sheet, describing: “1. A system for removing an interleaf sheet contacting a plate sheet used in an imaging system, comprising: a substantially horizontal member; an assembly comprising at least two elements configured to directly contact and pick up the interleaf sheet, a portion of said assembly connected to said member; a motor configured to move said member in a direction substantially perpendicular to a surface of the interleaf sheet as positioned prior to contact; and a sensor system that generates a signal indicating when said member is a first predetermined distance from the interleaf sheet; said motor utilizing the first predetermined distance to move said member a second predetermined distance from the interleaf sheet, the at least two elements not contacting each other at the second predetermined distance, said motor moving said member in a direction toward the first predetermined distance to a position where at least a portion of the interleaf sheet is interposed between the at least two elements.”
Claim 36 of published patent application US 2006/0117975 discusses a system for picking up plate, describing: “36. A system for raising a plate sheet for use in an imaging system comprising an imager, comprising: a substantially horizontal member; at least one element configured to directly contact and vertically raise the plate sheet, a portion of said at least one element connected to said member; a motor configured to raise said member in a direction substantially perpendicular to a surface of the plate sheet as positioned prior to contact; and a sensor system that generates a signal indicating when said member is a first predetermined distance from the plate sheet; said motor utilizing the first predetermined distance to move said member a second predetermined distance, thereby raising the plate sheet.”
Claim 41 of published patent application US 2006/0117975 depends upon such claim 36 and further describes a rail system for moving the plate sheet as follows: “41. The system according to claim 36, further comprising a rail system for moving the plate sheet in a direction away from the imager, to thereby substantially align a trailing edge of the plate sheet with a trailing edge of a second plate sheet positioned beneath said plate sheet.”
The devices utilized in the prior art (such as, e.g., the devices described by such claims 1, 36, and 41) utilize a one-arm assembly to pick up plates out of a cassette and transfer them into an imaging system; that same arm assembly is also used to pick up interleaf sheets and dispose the interleaf sheets into a chute. As described hereinabove, and with reference to such published patent application, claim 1 describes the system for removing the interleaf sheets, claim 36 describes the system for picking up plates, and claim 41 describes the rail system that the arras travels on. The published patent application patent shows both the interleaf removal mechanism and the plate pick mechanism on the same arm assembly.
It is an object of this invention to provide a device with a substantially greater speed of operation than the prior art devices and, in particular, than the device disclosed in published United States patent application 2006/0117975.
In accordance with this invention, there is provided a system for removing an interleaf sheet contacting a plate sheet used in an imaging system, comprised of a substantially horizontal member; an assembly comprising at least two elements configured to directly contact and pick up the interleaf sheet, a portion of said assembly connected to said member; a motor configured to move said member in a direction substantially perpendicular to a surface of the interleaf sheet as positioned prior to contact; and a first sensor system that generates a signal indicating when said member is a first predetermined distance from the interleaf sheet; and a second sensor system comprised of a second sensor that generates a signal indicating that the sheet beneath the second sensor is an interleaf sheet; said motor utilizing the first predetermined distance to move said member a second predetermined distance from the interleaf sheet, the at least two elements not contacting each other at the second predetermined distance, said motor moving said member in a direction toward the first predetermined distance to a position where at least a portion of the interleaf sheet is interposed between the at least two elements.
The invention will be described by reference to specification and the accompanying Figures, in which like numerals refer to like elements, and wherein:
The present invention relates generally to a system and method for removing and/or separating an interleaf sheet from a plate sheet and/or transporting a plate sheet, used in connection with, for example, Computer-to-Plate (CTP) imaging systems.
Rail apparatus 116 can be used to move apparatus 114 in the direction of arrows 226, 228. Optical sensor 244, which can be mounted in a fixed position, and having teeth 244a, 244b, can be used to control movement of apparatus 114. Flag 248 can be received between teeth 244a, 244b to block an optical signal between the teeth. When the optical circuit is completed between teeth 244a, 244b, movement in direction 226, 228 can be stopped. Optical sensors 238, 240, and 242 can be configured the same as or similarly to sensor 244 to control movement and/or position, as will be described herein.
Rail apparatus 116 can include a mounting plate 222 which, in turn, is secured to member 250. Motor 208 is used to drive shaft 216 which, in turn, moves apparatus 114 in the direction of arrows 230, 232. Shaft 216 can be, for example, a conventional screw shaft. Member 250 can be attached to or be an integral part of mounting plate 222. Horizontal slide rail 218 can be attached to or an integral part of member 250. Vertical plate 252 can have an attachment or integral part thereof that mates with and receives horizontal slide rail 218 to facilitate movement of apparatus 114 in the direction of arrows 230, 232. The length of shaft 216 and/or collar 256 contact with member 202 can be used to limit movement of apparatus 114 in the direction of arrow 230. Flag 254 and sensor 242 are used to limit movement of assembly in the direction of arrow 232.
Sensor 238 may used to indicate that member 212 is at or near a home position. Flag 266 is attached to or integral with, for example, a bottom surface of motor mount 270. When member 212, having sensor 240 attached thereto, moves in the direction of arrow 236, a home position can be determined when flag 266 cuts of the signal between the teeth of sensor 238. In
Motor 210 is used to drive shaft 258 which, in turn, moves apparatus 114 in the direction of arrows 234, 236. Shaft 258 may be, for example, a conventional screw shaft. Vertical position member 212 can have an attachment or integral part thereof that mates with and receives vertical slide rail 262 to facilitate movement of apparatus 114 in the direction of arrows 234, 236. Flag 248 and sensor 240 are used to determine the distance of member 202 from an interleaf sheet or plate sheet 335. The length of shaft 258 and/or collar 260 contact a top surface of motor 210, and is used to limit movement of apparatus 114 in the direction of arrow 234.
Plate height sensor member 205 can be used to determine the distance of member 202 from an interleaf sheet or a plate sheet 335. When sensor member 205 contacts an interleaf sheet or plate sheet 335, member 202 continues to move in the direction of arrow 234, and shaft 264 will remain stationary relative to interleaf sheet or plate sheet 335. Flag 248 can be attached to or integral with a top portion of shaft 248, such that as member 202 continues to move in the direction of arrow 234, flag 248 will block the optical signal of sensor 240. The blocking of the optical signal can be associated with a distance of member 202 to an interleaf sheet or plate sheet 335.
In the case of an interleaf sheet, motor 210 continues to drive member 202 in the direction of arrow 234, and thereby activate roller assemblies 200a, 200b, as will be described herein. Movement of member 202 in the direction of arrow 234 is not normally limited by collar 224 contacting a bottom surface of member 202 and/or collar 260 contacting a top surface of motor 210. Movement of member 202 in the direction of arrow 234 is of a predetermined distance, starting from the time when member 205 makes contact with the interleaf sheet, to the time when flag 248 blocks the optical signal of sensor 240. This predetermined distance may be optimized to best secure the interleaf sheet between rollers 202a, 204a and 202b, 204b. After an interleaf sheet is received between rollers 202a, 204a and 202b, 204b, motor 210 is used to raise apparatus 114 in the direction of arrow 236.
When apparatus 114 removes an interleaf sheet, rail apparatus 116 can then be activated to move apparatus 114 in the direction of arrow 226, to position the interleaf sheet over disposal rollers 302a, 302b. Disposal rollers can be driven by at least one motor and belt assembly (not shown) to rotate rollers 302a, 302b respectively in the direction of arrows 304a, 304b. Motor 210 can be used to lower apparatus 114 in the direction of arrow 234 so that the interleaf sheet contacts the disposal rollers 302a, 302b and conveys the interleaf sheet to rollers 302a, 302b. Upon disposing of the interleaf sheet, motor 210 can be used to raise apparatus 114 in the direction of arrow 236. Rail apparatus 116 can be used to move apparatus 114 in the direction of arrow 228, so that suction cups 206a, 206b can pick up a plate sheet 335, and feed the plate sheet 335 to input shelf 108 for subsequent imaging.
In the case of a plate sheet 335, vacuum pump 118, operatively connected to suctions cup 206a, 206b by, for example, one or more hoses, is activated. The suctions cups 206a, 206b, by vacuum, hold the plate sheet 335 in contact with the vacuum cups 206a, 206b. Movement of member 202 in the direction of arrow 234 is again limited by a predetermined distance. After an interleaf sheet is received between rollers 202a, 204b and 202b, 204b, motor 210 can be used to raise apparatus 114 in the direction of arrow 236.
Once the suction cups 206a, 206b contact a plate sheet 335, in one embodiment of the invention, the following sequential, non-sequential or sequence independent operations may take place. Referring to
The plate sheet 335 is held in the raised (in the direction of arrow 236) position for approximately 3-5 seconds, thereby allowing an interleaf sheet that may be adhering to a bottom surface of the plate sheet 335, in the vast majority of cases, to separate and fall back in to place to the stack. The interleaf may not fall/separate from the bottom of the plate sheet 335 in all instances. To minimize any relative motion between the interleaf sheet and the plate sheet 335 under these circumstances, apparatus 114, holding plate sheet 335, moves further in the direction of arrow 236, and slightly in the direction of arrow 228 to minimize or eliminate any sliding of the plate sheet 335 relative to the interleaf sheet underneath the plate. Relative motion may be caused by sagging at the opposing end of the plate sheet 335 from which the suction cups 206a, 206b are holding the plate sheet 335. The sagging causes the opposing end of the plate sheet 335 to drop vertically. The opposing edge of the plate sheet 335, by virtue of dropping vertically, also moves slightly toward suction cups 206a, 206b (in the direction of arrow 226), which is compensated for by the apparatus 114 moving in the direction of arrow 228.
Whether or not the interleaf sheet has dropped back to the stack or adheres to the bottom of the plate sheet 335, ionizer 272 is activated, which creates an air cushion. A compressed air cylinder (not shown) may be used in conjunction with ionizer 272, which causes static charges to dissipate. Any interleaf sheet that may have been adhering to the bottom of the plate sheet 335 will now fall back to the stack. In either case, static charges will be dissipated. Ionizer 272 can be operated for approximately 5 seconds to dissipate any static charges. Rail 116 is then engaged to move apparatus 114 and the plate sheet 335 in the direction of arrow 226, thereby moving the plate sheet 335 along the air cushion, and on to the input shelf 108 where the plate sheet 335 is positioned and released for imaging.
Axles, preferably made of metal (e.g., stainless steel), are respectively received in holes 410, 412 of members 406, 408. The axles are also similarly received in corresponding holes (not shown) of members 414, 416. Members 406, 408 and 414, 416 rotate about hinge pin 446. Members 406, 408 and 414, 416 are respectively arranged in a scissors-like configuration. A recess 442 can be provided on members 406, 416 to limit the movement of members 408, 414 as the bottom portion of members 406, 408, 414, 416 move in the direction of arrows 448. Screws 434, 444 can be provided on members 406, 408, 414, 416 to hold the axles in place so that they do not rotate relative to members 406, 408, 414, 416. In this manner, roller clutch bearings (not shown) can be used to prevent rotation of rollers 402, 404 when rollers 402, 404 move towards each other, in the direction of arrows 424.
Member 436 and hinge pin 446 form a single piece. Rod 418 is operably connected and/or in contact with a cutout surface 438 of member 436 and hinge pin 446 such that when rod 418 is pushed in the direction of arrow 234, member 436 and hinge pin 446 can distribute the force to members 406, 408, 414, 416, thereby causing members 406, 408, 414, 416 to move in the direction of arrows 448.
Members 406, 408 are respectively provided with holes 432, 450. Members 414, 416 are provided with similar holes (not shown). Member 406 and its respective hole 432, and member 416 having a respective hole (not shown), receive link 430. Similarly, member 408 and its respective hole 434, and member 414 having a respective hole (not shown) receive link 428. One or more retaining rings 440 can be used to secure links 428, 430 to respective members 408, 414 and 406, 416. Springs 420, 422 are secured to links 428, 430 to provide a force in the direction of arrows 424. The force increases as rollers 402, 404 move in the direction of arrows 448. At equilibrium, springs 420, 422 can provide a force in the direction of arrows 424 such that rollers 402, 404 contact each other with some amount of pinch force.
Rollers 402, 404 rotate freely with minimal bearing friction when moving in the direction of arrows 448. When moving in the direction of arrows 448, rollers 402, 404 contact interleaf sheet 502, and can produce a constant or variable contact force.
At a point where the outward spacing of the rollers is sufficient to grasp interleaf sheet 502 as shown in
When rollers move in the direction of arrows 424, they are not free to roll on interleaf sheet 502. In an embodiment, standard clutch bearings (not shown) coupled to rollers 402, 404 in a conventional manner can be used to provide unidirectional rotation of the rollers 402, 404 respectively in the direction of arrows 504, 506, and prevent rollers 202, 204 from rotating when they move in the direction of arrows 424. Because rollers 402, 404 do not rotate when they move in the direction of arrows 424, interleaf sheet 502 “buckles up” into a small loop, as shown at 508 in
Transfer housing 906a and 906b can be connected to or integral with connection housing 908. An optionally tapered opening 914 can be provided at an end of transfer housing 906a to receive interleaf sheets from pick up roller carriage 901. One or more driven rollers 1a-1f can be mounted to or integral with a first side of transfer housing 906a, 906b. Rollers 1a-1f can be driven by a motor and belt (not shown). One or more blocks 924 can be connected to or integral with the first side of transfer housing 906a, 906b, and rollers 1a-1f can be connected to or integral with the respective blocks.
One or more non-driven rollers 2a-2f can be mounted to or integral with a second side of transfer housing 906a, 906b. Rollers 1a-1f can contact rollers 2a-2f so that rollers 2a-2f rotate with driven rollers 1a-1f. A block 926 can be connected to or integral with the second side of transfer housing 906a, 906b, and rollers 2a-2f can be connected to or integral with the respective blocks.
A suction cup apparatus, generally at 910, can optionally be provided and/or utilized in connection with interleaf sheet removal apparatus 900. Suction cups 912a, 912b can be used to pick up plate sheets 335. Egress chute 918 can have a first end that receives interleaf sheets from transfer housing 906b, and a second end that allows the interleaf sheets to exit.
As is shown in
In
The device depicted in
Separating the functions onto two arm assemblies allows the machine to load plates much faster into the imager than prior art devices because the arm does not have to let one operation finish before it starts the next. The arms work simultaneously to limit the waiting period between operations. This greatly increases throughput of the machine. In one embodiment, the CTP machine with the new dual pick up arm system can output 120 or more plates per hour compared to prior art machines, which typically output 60 plates per hour.
The operation of the new design is as follows: The plate pick up arm picks up a plate in the cassette using the vacuum cups and then brings the plate to the input shelf to be registered on the pins. As soon as the plate is out of the cassette, the interleaf sheet removal arm moves to pick up the interleaf sheet in the cassette. While the pick up arm is registering the plate against the pins, the interleaf sheet arm is picking up the interleaf sheet and the moving it to the disposal rollers and the rollers dispose the sheet in a holding bin below. The pick up arm finishes registering the plate and then only has to pause momentarily to allow the interleaf arm to finish disposing the interleaf sheet. Then the pick up arm can pick up the next plate.
The following figures show many of the same elements that are described in
Referring again to
The device depicted in
As will be apparent from such
This patent application claims priority based upon patent application 60/880,893, the entire disclosure of which is hereby incorporated by reference into this specification. This application also is a continuation-in-part of applicants' copending patent application U.S. Ser. No. 11/296,527, filed on Dec. 8, 2005, which was published as (U.S. 2006/0117975) on Jun. 8, 2006. The entire disclosure of such patent application is hereby incorporated by reference into this specification.
| Number | Date | Country | |
|---|---|---|---|
| 60880893 | Jan 2007 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11296527 | Dec 2005 | US |
| Child | 12009107 | US |
