Plate mounting device for imprinters

Abstract: A plate mounting device for an imprinter has an imprinter plate cylinder (20) having a magnetized outer surface (22), and having one or a plurality of positioning pin holes (23A, 23B, 23C) provided near a portion near an end of a plate (25) to be mounted on the imprinter plate cylinder (20). A ferromagnetic base plate (25) is mounted on the imprinter plate cylinder (20). The ferromagnetic base plate (25) has a plate face provided with pin through-holes (25B) which are brought into alignment with the positioning pin holes (23A, 23B, 23C) so as to position the plate (25). When the base plate (25) is mounted on the imprinter plate cylinder (20), those of the positioning pin holes which are not used are filled with magnetic pins (24).

Description: This invention relates to a plate mounting device for an imprinter which imprints a part of a main printing on printing paper. DESCRIPTION OF THE PRIOR ART Department stores, supermarkets, convenience stores, car dealers domestic electric products stores, etc. do their business by selling common goods by a number of stores in wide areas. In this business, a number of advertisement leaflets common among their respective stores are used. In distributing these advertisement leaflets, or inserting them in newspapers to deliver them home, the names of their respective stores and advertisements of their own stores, e.g., sales dates, sales periods, are imprinted on the leaflet advertisements. In a rotary press, when a part of such an advertisement leaflet is imprinted, an imprinter is located before or after color printing units for printing the main printing. In the rotary press of FIG. 10 for example, an imprinter 4 is located before printing units 5. The imprinter imprints paper 3 fed from a web 2 of a reel stand 1, and then the printing units 5 print a main body of a printing in multi-colors, e.g, four colors. Subsequently the ink is dried by a drier 6, and then the printed paper is fed to a folder 7 to be cut in sheets or folded to be discharged. In the conventional letter press-type imprinter, an imprinting plate is adhered to a plate cylinder with a both-side adhesive tape. FIG. 9 shows an example of mounting a plate onto a plate cylinder. Lines are drawn on the surface of a plate cylinder 8 for positioning a plate 9. The edge of the plate 9 is adhered along a line 10. The adhering position of the plate is determined by which part of a main advertisement printing an imprinting is made on. A required number of the plate 9 are prepared in accordance with a number of imprinting positions. When there are two imprinting positions as examplified in FIG.9, two sheets 9A, 9B of the plate are prepared. In imprinting different letters, pictures, etc. on respective units of a divided number of a required number of advertisement leaflets, a plate corresponding to one of the units is adhered to the plate cylinder of an imprinter, and an imprinting is performed. When the imprinting is finished, the rotary press is paused to peel the plate off the plate cylinder. Then a different plating is adhered to the plate cylinder, and the imprinting is resumed. As a number of imprintings is increased, a time of replacing plates is increased. In the above-described case, the plates replacing operation performed in the press. Consequently the operation of replacing the plates is unefficient. Even when necessary plates are prepared, because of the indispensable steps of adhering and peeling the plates to and off the plate cylinder, much time is taken for the steps especially in the case where many plates have to be replaced. This leads to lower printing efficiency. After a plate is mounted, an actual imprinting is performed to confirm whether or not the plate is located at its correct position. If the plate is dislocated, the plate is peeled off to be relocated at the correct position. Thus the replacement of the plates consumes much time. Furthermore, even when small parts of main advertisement leaflets printings are imprinted, plate cylinder full width-sized plates are used, and accordingly the plates are not effectively used. Besides, their large size increases the plate cost and takes a larger storage space for their re-use. US-A-4 809 609 discloses a letter printing device where the individual plates are directly mounted to the cylinder body, positioned by positioning pins and held by magnetic forces. The positioning pin holes are spread over the whole cylinder surface. The through holes of the individual imprinting plates have to be drilled by means of a special proofing table so that each imprinting plate may be correctly positioned and registered on the cylinder surface. US-A-2 774 302 discloses a printing device where each imprinting plate on the back is coated with a ferro-magnetic or magnetizable sheet and is individually positioned on the cylinder body by means of lines drawn on the cylinder surface. SUMMARY OF THE INVENTION This invention has been made to solve the above-described problems. An object of this invention is to provide a plate mounting device for an imprinter in which a plate is mounted on the plate cylinder through the intermediary of a base plate. Another object of this invention is to provide a plate mounting device for an imprinter which allows small-sized base plates to be used. In order to achieve the above-described objects, this invention relates to a plate mounting device for an imprinter, in which a ferromagnetic base plate carrying one or more imprinting plates is mounted on the plate cylinder body having a magnetized outer face, the device comprising a plate cylinder body, whose outer face is magnetized or provided with a magnetic sheet attached to the surface thereof; a ferromagnetic base plate having a plate face; one or a plurality of positioning pin holes formed in a portion of the plate cylinder body near an end of a base plate mounted thereon; pin through-holes formed in the base plate which are brought into alignment with the positioning pin holes in the plate cylinder body to position the base plate; and magnetic pins for filling unused ones of the positioning pin holes. According to one preferable aspect of this invention, the positioning pin holes are formed in the plate cylinder body in one or a plurality of pairs, the pin through-holes are formed in the base plate in at least one pair, and the pin through-holes are brought into alignment with one of the pairs of the positioning pin holes so as to position the imprinting plates at an imprinting part. According to this invention, a required number of base plates can be prepared outside a press. The replacement of the base plates can be quickly performed. Consequently a pause of the press can be shortened. Resultantly the printing efficiency is improved, and small lots can be imprinted. A plurality of different pattern base plates can be mounted on a cylinder body by one replacement. This is very effective when imprintings are made on a plurality of parts of a main advertisement printing. The dislocation of an imprinting plate, incorrect adhesion of an imprinting plate, etc. can be checked before a printing operation. Consequently the preparetory operation can be drastically shortened. Necessary minimum sized plates can be used. Resultantly the plate cost can be reduced, and a storage space for re-uses of the plates can be diminished. BRIEF DESCRIPTION OF THE DRAWINGS FIG.1 is a perspective view of the plate cylinder body used in an embodiment of this invention; FIG.2 is a vertical sectional view of the plate cylinder body along the line I - I ; FIG.3 is a view of a state where positioning pin holes are filled with magnetic pins; FIG.4 is a partially broken view of a structure of the magnetic pins; FIG.5 is a plan view of the base plated; FIG.6 is a side view of the base plate; FIG.7 is a perspective view of the plate cylinder body with a base plate and imprinting plates mounted on; FIG.8 is a side view of the perspective view of FIG.7 along the line II - II ; FIG.9 is a perspective view of a plate cylinder of the conventional imprinter ; and FIG.10 is a schematic view of the structure of the rotary press with an imprinter incorporated in. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of this invention will be explained below with reference to the drawings. FIG.1 shows a preferred embodiment of this invention. In FIG.1, a plate cylinder body 20 has a plate mounting groove 21 formed in the cylinder surface parallel with the rotation axis thereof. A magnetic sheet 22 is adhered to the part of the cylinder surface except the plate mounting grooves 21. In the portion of the cylinder surface near the plate mounting groove and opposite to a rotational direction of the plate cylinder body (indicated by the arrow "a" in FIG.2) there are provided positioning pin holes 23 which pass through the magnetic sheet 22 down to a depth which reaches a required depth of the plate cylinder body 20. The positioning pin holes 23 are used to position a base plate 25, which will be described later, when the base plate 25 is mounted on the plate cylinder body. The number of the holes 23 is one or plural. The positioning pin holes 23 are provided in a plurality of pairs, e.g., three pairs (23A, 23B, 23C), at a required interval, depending on base plate mounting positions or others corresponding to various sizes of base plates, and positions where the base plates are positioned. Those of the positioning pin holes which are not used are filled with magnetic pins 24 as shown in FIG.3. Each magnetic pin 24 comprises a permanent magnetic 24B secured to a pin body 24A. The magnetic pin 24 shown in FIG.4 is attached by screw-engaging the thread 24C of the pin body 24A with the thread 23A of a positioning pin hole 23. At this time a part of the top surface of the permanent magnetic 24B is substantially flush with the surface of the plate cylinder body or respective magnetic sheet 22. Resultantly in the vicinity of the end portions of the base plate 25, a loss of a magnetic force of the plate cylinder face due to the pin holes 23 in the magnetic sheet 22 can be supplemented, so that base plate 25 is prevented from floating or lifting in the edge portion. As shown in FIG.5, the base plate 25 has a required minimum width which is sufficiently smaller, than width of the plate cylinder body, and is made of a magnetic material which is attractable by a magnetic force of the magnetic sheet 22. As shown in FIG.6, the base plate 25 has a bent portion 25A formed on one side thereof to be inserted and locked in a plate mounting groove 21 in the cylinder body. In the portion of the base plate 25 near the bent portion 25A there are provided a pair of pin through-holes 25B along the bent portion 25A. The interval between the pin through-holes 25B of the pair is equal to that between the positioning pin holes 23 of a pair, e.g., the pair 23A. A required number of base plates 25 are prepared before a printing operation is started, and imprinting plates 9A, 9B,···are adhered beforehand to the surface of the base plates with a both side adhesive tape in accordance with a kind of imprinting and an imprinting position. Next, the mounting of the base plate on the plate cylinder body will be explained. FIG.7 shows the plate cylinder body with the base plate mounted on. A required number of base plates 25 are prepared in accordance with a number of different imprints, and imprinting plates 9A,9B,··· are adhered beforehand to the base plates. Those of the pin positioning holes 23 which are not used are filled with the magnetic pins 24. Each base plate with the imprinting plates adhered to is suspended by tool pins (not shown) inserted in both pin through-holes 25B. Each tool pin is inserted into a positioning pin hole 23 of the plate cylinder body 20 with the plate mounting groove 21 laid horizontal. The bent portion 25A of the base plate is inserted into a plate mounting groove 21 of the plate cylinder body. In this state, the base plate 25 is suspended down with the portion near the bent portion attracted by a magnetic sheet 22 and the magnetic pins 24. Then, the plate cylinder body is rotated in the direction indicated by the arrow "b" to wind the suspended base plate onto the plate cylinder body and to be attracted by the magnetic sheet. When a base plate is replaced, the portion of the base plate on the side of the bent portion is peeled off, and with the portion held with a hand the plate cylinder body is rotated in the direction indicated by the arrow "b". Then a different base plate is mounted in the above-described way. In this embodiment the plate mounting groove is formed in the plate cylinder body, but it is not essential to provide the plate mounting groove. In the latter case, the base plate has no bent portion. In this invention, the plate cylinder body with the outer surface magnetized is prepared by adhering a magnetic sheet to the outer surface of the plate cylinder body, but the plate cylinder body per se may be magnetized in place of the magnetic sheet.

Claims: A plate mounting device for an imprinter comprising a plate cylinder body (20) having a magnetized outer surface, wherein said outer surface has a plurality of positioning pin holes (23) provided therein for positioning imprinting plate means to be mounted on said plate cylinder body (20), characterized in that said positioning pin holes (23) are located near where an end of a ferromagnetic base plate (25) adapted to carry imprinting plates (9) is to be mounted on the plate cylinder body (20), said base plate (25) having a plate face with pin through-holes (25B) which are positioned in alignment with some of the positioning pin holes (23) of the plate cylinder body (20); and magnetic pins (24) being provided filling those of the positioning pin holes (23) which are not in use when the base plate (25) is mounted on the plate cylinder body (20). A plate mounting device according to claim 1, characterized in that the plate cylinder body (20) has a magnetic sheet (22) adhered to the outer surface thereof. A plate mounting device according to any one of claims 1 and 2, characterized in that the positioning pin holes (23A, 23B, 23C) are formed in the plate cylinder body (20) in one or a plurality of pairs, and that the pin through-holes (25B) are formed in the base plate (25) in at least one pair corresponding to one of the pairs of positioning pin holes (23). A plate mounting device according to any one of claims 1 to 3, characterized in that the base plate (25) is mounted on the plate cylinder body (20) with the imprinting plates (9A, 9B) adhered to the base plate (25) beforehand.

Inventors: KAWAZOE KAZUTERU, KAWAZOE, KAZUTERU
Applicants: B J TRADING KK, B-J TRADING LIMITED
Application year: 1991
Main classification: B41F27
IPC codes: B41F27