US 4,064,804 A · Duplicator and method of duplicating

Abstract

A duplicator system and method are provided for preparing a lithographic master and for producing duplicated copies from the master in a fully automated system. An ink and moisture system is provided for supplying ink and moisture to a master on a master cylinder. During a pre-inking phase, an ink ductor roller is operative for a predetermined duration within variable ranges, as determined by the number of duplicated copies to be reproduced, and a moisture roller is operative to transmit moisture to the inking system. An early moisture circuit is also provided for conditioning the system by supplying moisture prior to a pre-inking phase in those instances wherein there has been a significant delay between the processing of two consecutive masters. Control means including a sensing device is provided for sensing the ambient temperature at an ink fountain and providing an indication thereof at predetermined temperature values. Subsequent to the pre-inking phase and during a normal duplicating operation, in response to an indication of the sensed temperature, the speed of transfer of ink from the ink fountain to the ink form roller is automatically controlled by altering the movement of the ink ductor roller, i.e. by interrupting the ducting action of the ductor roller for preselected time intervals. Thus, as the viscosity of the ink changes in response to the temperature, the control means is effective to vary the ducting pattern of the ink ductor roller such that an amount of ink substantially suited to the temperature situation is applied to the master.

Claims18

Dependent claims

The method of lithographic duplicating on a rotary lithographic duplicator which comprises applying ink from an ink fountain to a lithographic master on a master cylinder by means of an ink train including a fountain roller and an ink form roller, which includes the steps of:

sensing the temperature at the ink fountain and generating electrical signals indicative thereof;
and
in response to said signals automatically controlling the speed of transfer of ink from the ink fountain roller to the ink form roller in inverse relation to the temperature level sensed.

A rotary lithographic duplicator comprising:

a master cylinder;
means for inserting lithographic masters on the master cylinder and ejecting them therefrom;
means for automatically preparing and processing the lithographic masters prior to their insertion on the master cylinder;
means for applying lithographic ink to the master on the master cylinder comprising an ink fountain and an ink train including an ink fountain roller and an ink form roller;
a moisture train for supplying moisture to the surface of the master on the master cylinder;
means for sensing the temperature at the ink fountain and generating electrical signals indicative thereof;
means responsive to said signal for controlling the speed of ink transfer from the ink fountain roller to the ink form roller;
means for interrupting operation of the moisture train to prevent the forwarding of moisture concomitantly with a used master being ejected from the cylinder;
means for measuring the time between the departure of the used master from the master cylinder and the preparation of a new master and giving a signal when the measured time exceeds a predetermined normal dry-out time for the moisture train;
means responsive to preparation of the new master in the absence of said signal for restoring operation of the moisture train concomitantly with insertion of said new master on the cylinder;
and
means responsive to preparation of said new master after said signal is given for restoring operation of said moisture train during the preparation of the new master substantially in advance of its insertion on the master cylinder.

9 more elements

Dependencies are inferred from the claim text.

Duplicator and method of duplicating

Life of this patent

Duplicator and method of duplicating

Life of this patent

Abstract

Claims18