Rotary offset sheet printing machine for prime and verso printing

Abstract

To minimize the number of components of the printing system and require only a single impression cylinder, a sheet transport chain is carried about a second one of three rubber cylinders (3, 5, 7) to receive a sheet from the impression cylinder (2) to which the sheet is first applied for a first prime printing by a first rubber cylinder (3), the sheet being led about the second rubber cylinder and between a third rubber cylinder (7) which applies verso printing thereon, with the second rubber cylinder acting as a counter or impression cylinder for the third rubber cylinder; each one of the rubber cylinders has a plate cylinder (4, 6, 8) associated therewith, the second rubber cylinder applying the second prime print being positioned above the chain drive, the first rubber cylinder and the first plate cylinder being positioned above the impression cylinder (2) and the third blanket cylinder and the third plate cylinder being positioned below the printing cylinder, thus providing for compact construction of the respective cylinders and associated equipment such as damping fountains, ink trains, and the like, without impairment of accessibility to the components of the machine.

Description

Cross reference to related application, assigned to the assignee of the present application:

U.S. Ser. No. 308,363, filed Oct. 5, 1981, Fischer et al. first third rubber blanket cylinder 7 which cooperates with a plate cylinder 8 and which applies the subject matter of the verso print.

The sheet supply stack 9, from which the sheet is transported to the printing cylinder 2, can be in accordance with any well known and suitable and commercial structure, for example by means of a gripper arrangement. Upon rotation of the printing cylinder 2 and the first rubber cylinder 3, the first prime printed subject matter is applied and, upon continued rotation, the printing cylinder 2 transfer the sheet to a chain transport system 10 which is looped about the second rubber blanket cylinder 5. The chain transport system 10--which may be constructed in accordance with any well known and suitable structure--as customary has two chains carried parallel to the ends of the respective cylinder, with transverse bars extending thereacross carrying grippers 13. The grippers 13 accept the sheets from the impression cylinder 2 and are carried thereby about the rubber blanket cylinder 5, rotating in clockwise direction. The second prime printing is applied between the second rubber cylinder 5 and the impression cylinder 2. Thereafter, a back side or verso print is applied by the third rubber cylinder 7, and the sheet then continues to be transported by the gripper system 13 of the chain 10 to the delivery system 11 which, in its simplest form, is a stack of sheets. Upon transfer of the sheets from the impression cylinder 2 onto the chain system 10, the grippers 13 engage in a groove 12 of the blanket cylinder 5. A similar groove, of course, will be present in the impression cylinder 2 which accepts grippers, as well known.

The printing system 1 thus utilizes the blanket cylinder 5 as the blanket cylinder for one of the prime printing subject matter as well as the impression cylinder for the third blanket cylinder 7 which applies the verso print. The sheet is taken out of the printing system 1 either directly with the single chain system 10 for stacking on the stack 11; the chain system 10, with the grippers 13 thereon may, of course, also supply the sheets to other delivery apparatus, or to a further printing station which may by be similar to the printing station 1, for example, for subsequent printing thereon in prime and verso printing, respectively.

The structure can be compactly arranged. The rubber cylinder 7 and the associated plate cylinder 8 are located beneath the impression cylinder 2; the rubber blanket cylinder 5 associated with the second plate cylinder 6 is positioned above the chain transport system 10. The first rubber cylinder 3 and the associated plate cylinder 4 are located above the impression cylinder 2. The respective ink trains, as well as the damping fountain systems associated with the rubber cylinder-plate cylinder pairs, are shown only schematically; as can be seen from the FIGURE, the particular placement of the plate cylinder-rubber cylinder pairs about the impression cylinder with the specific arrangement of the path of the chain 10 provides for compact construction without impairment of accessibility of components of the printing cylinder.

Various changes and modifications may be made within the scope of the inventive concept.

Claims

1. Rotary offset sheet printing machine for prime and verso printing having

an impression cylinder (2);

three paired rubber cylinder-plate cylinder combinations (3, 4; 5, 6; 7, 8), each including a first, second and third rubber cylinder (3, 5, 7) and a first, second and third printing plate cylinder (4,6,8), a first prime printing being applied to the sheets by the first rubber cylinder-plate cylinder combination (3,4) while the sheets are transported between the first rubber cylinder (3) and the impression cylinder (2);

and a transport chain system including gripper means (13) and a chain (10) to transport sheets between the first rubber cylinder (3) and from the impression cylinder (2) for first prime printing and past partly around the second rubber cylinder (5) for second prime printing, and further past the third rubber printing cylinder (7) for verso printing,

wherein, in accordance with the invention,

the transport chain 10 (10) is carried about the second rubber cylinder (5) and receives sheets from the impression cylinder (2) and leads said sheets over part of the circumference of the second rubber cylinder (5) to thereby have the second prime printing applied, and further lead the sheets against between the third rubber cylinder (7) between and the second rubber cylinder (5) to have the verso printing applied, the second rubber cylinder (5) forming the counter cylinder for the third rubber cylinder (7).

2. printing machine according to claim 1, wherein a sheet delivery system (11) is provided, and the transport chain transports the sheets from the third blanket rubber cylinder to said delivery system.

3. printing machine according to claim 1 or 2, wherein the third rubber cylinder applying the verso printing and the associated plate cylinder (8) are located below the impression cylinder (2);

the second rubber cylinder (5) applying the second prime print and the associated plate cylinder (6) are located above the transport chain system (10);

and the first rubber cylinder applying the first prime print, and the associated plate cylinder (4) are positioned above the impression cylinder.