Print unit

Details Print unit Print unit

2000-01-28

2001-12-25

Yan, Ren (Department: 2854)

Printing

Multicolor

Rotary machines

C101S216000, C101S217000, C101S220000, C101S221000

Reexamination Certificate

active

06332397

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to a print unit of an offset printing press. The forme cylinder is driven by a motor while the transfer cylinder is driven by a separate motor.
DESCRIPTION OF THE PRIOR ART
A rotary offset printing press with rubber blanket and plate cylinders is known from EP 0 644 048 A2. For their common drive, these rubber blanket and plate cylinders are combined in pairs into cylinder groups by a mechanical coupling. Each such cylinder group is respectively driven by its own drive motor.
DE 44 30 693 A1 discloses print units of a rotary offset printing press, wherein at least one cylinder is individually driven, and in which associated plate and rubber blanket cylinders are combined into groups for being driven.
Later published EP 0 812 683 A1 describes a web-fed rotary printing press, wherein each print unit has a forme, a rubber blanket and a printing cylinder. The forme cylinder of each print unit has its own drive motor.
SUMMARY OF THE INVENTION
The object of the present invention is based on providing a print unit.
In accordance with the present invention, this object is attained by the provision of a print unit of an offset printing press with a forme cylinder having its own drive motor, and of a transfer cylinder with its own motor. If there are two forme cylinders, each has its own drive motor. The two transfer cylinders can be coupled and driven by their own drive motor. Alternatively, the transfer cylinder and its associated counter-pressure cylinder can be driven by a common drive motor.
Mechanical devices for adjusting the circumferential registration are omitted in an advantageous manner in the print unit of the present invention. If an adjustment of the circumferential registration is performed with the aid of the separate drive of the plate cylinders by changing a phase position of the plate cylinders in respect to each other, a relative angle of rotation position of the rubber blanket cylinders in respect to each other remains unchanged. Channels of the rubber blanket cylinders remain in an unchanged position in relation to each other. The position of a channel of a plate cylinder does change in relation to the channel of the associated rubber blanket cylinder, but since the channel, which forms a non-printing area of the plate cylinder is customarily smaller than the channel of the associated rubber blanket cylinder, the channel of the plate cylinder does not exceed the area of the channel of the rubber blanket cylinder.
Therefore, the printing area, as a result of the channels of the rubber blanket cylinders, is not reduced, even when the circumferential registration is changed.
In comparison with prior print units, each of whose cylinders has its own individual drive, the outlay for the electrical equipment is considerably less in the print unit of the present invention.
It is possible, in particular for the flying change of printing plates (“imprinter”), to selectively stop each plate cylinder of a print unit, while the web is guided by the associated rubber blanket, or respectively by the counter-pressure, cylinders.


REFERENCES:
patent: 3606800 (1971-09-01), Treff et al.
patent: 4207815 (1980-06-01), Watanabe
patent: 4218972 (1980-08-01), Fujidhiro
patent: 5429051 (1995-07-01), Laubscher
patent: 5535677 (1996-07-01), Fannin et al.
patent: 5619921 (1997-04-01), Iijima et al.
patent: 5706725 (1998-01-01), Kolbe et al.
patent: 5778779 (1998-07-01), Jones et al.
patent: 5782182 (1998-07-01), Ruckmann et al.
patent: 5826505 (1998-10-01), Volz et al.
patent: 5950538 (1999-09-01), Puschnerat
patent: 5953991 (1999-09-01), Geissenberger et al.
patent: 5979317 (1999-11-01), Singler
patent: 6050185 (2000-04-01), Richards
patent: 6138566 (2000-10-01), Sakamoto
patent: 4408025 A1 (1995-09-01), None
patent: 4430693 A1 (1996-03-01), None
patent: 0644048 A2 (1994-12-01), None
patent: 0812683 A1 (1997-04-01), None
patent: 46-5908 (1971-12-01), None
patent: 8-85196 (1996-04-01), None

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