Ink removal, circulating and distributing system

Claim 3

The method of claim 1 wherein the step of pumping the mixture comprises the steps of: pumping a portion of the mixture through a first line to a central portion of the nip; and pumping a portion of the mixture into the reservoir such that the mixture is removed from the reservoir at a faster rate than it is deposited in the central portion of the nip.

Claim 4

The method of claim 2 with the addition of the steps of: delivering fresh ink to the reservoir to replenish the mixture applied to the lithographic printing plate.

Claim 5

The method of claim 1 wherein the step of removing the mixture from a central portion of the reservoir comprises: removing mixtures from a central portion of a plurality of reservoirs which supply ink to different printing plates; mixing the mixtures to form a homogeneous mixture; and pumping the homogeneous mixture to central portions of a plurality of nips.

Claim 6

The method of claim 1 with the addition of the step of: maintaining a small volume of ink and dampening fluid in the reservoir; and pumping fresh ink into the reservoir when the level of the mixture of ink and dampening fluid falls below a predetermined level.

Claim 7

The method of claim 1 with the addition of the step of: adjusting the rate at which the mixture is pumped from a central portion of the reservoir to assure that flow longitudinally of the metering nip and toward the center of the reservoir is sufficient to prevent separation of dampening fluid from ink in the metering nip and to maintain a substantially homogeneous mixture of ink and dampening fluid in the reservoir.

Claim 8

In a printing system having a printing plate, a form roller engaging the printing plate, and apparatus to apply ink and dampening fluid to the printing plate, the improvement comprising: an ink transfer roller; an ink metering roller; means urging said ink transfer roller and ink metering roller into pressure indented relation to form a nip; means metering ink from the surface of the transfer roller onto the surface of the form roller; dispensing means for delivering ink into a central portion of said nip such that ink flows longitudinally of the nip in opposite directions and cascades over opposite ends of said transfer roller and metering roller; means for removing a mixture of excess ink and dampening fluid from said form roller after said form roller engages the printing plate; a collection reservoir positioned to receive ink cascading over ends of said rollers into opposite ends of the collection reservoir and to receive the mixture of ink and dampening fluid removed from said form roller; means removing ink from a central portion of said collection reservoir; means sensing the level of ink in the collection reservoir; means to add fresh ink to ink in the collection reservoir when the level of ink in the collection reservoir falls below a predetermined level; and pump means between the means removing ink from a central portion of the collection reservoir and said dispensing means, said pump means having sufficient capacity to circulate ink longitudinally of said nip at a rate sufficient to prevent accumulation of dampening fluid in said nip and sufficient to mix ink cascading over ends of said rollers with fresh ink periodically added to the collection reservoir and the mixture of excess ink and dampening fluid removed from the form roller to assure that a substantially homogeneous mixture of ink and dampening fluid is dispensed into the central portion of the nip.

Claim 9

In a printing system having a printing plate, a form roller engaging the printing plate, and apparatus to apply ink and dampening fluid to the printing plate, the improvement comprising: an ink transfer roller; an ink metering roller; means urging said ink transfer roller and ink metering roller into pressure indented relation to form a nip; means metering ink from the surface of the transfer roller onto the surface of the form roller; dispensing means for delivering ink into a central portion of said nip such that ink flows longitudinally of the nip in opposite directions and cascades over opposite ends of said transfer roller and metering roller; means for removing a mixture of excess ink and dampening fluid from said form roller after said form roller engages the printing plate; a collection reservoir positioned to receive ink cascading over ends of said rollers into opposite ends of the collection reservoir and to receive the mixture of ink and dampening fluid removed from said form roller; means removing ink from a central portion of said collection reservoir; means sensing the level of ink in the collection reservoir; means to add fresh ink to ink in the collection reservoir when the level of ink in the collection reservoir falls below a predetermined level; and pump means between the means removing ink from a central portion of the collection reservoir and said dispensing means, said pump means having sufficient capacity to circulate ink longitudinally of said nip at a rate sufficient to prevent accumulation of dampening fluid in said nip and sufficient to mix ink cascading over ends of said rollers with fresh ink periodically added to the collection reservoir and the mixture of excess ink and dampening fluid removed from the form roller to assure that a substantially homogeneous mixture of ink and dampening fluid is dispensed into the central portion of the nip.

Claim 10

The system of claim 7 with the addition of variable speed drive means drivingly connected to said pump means.

Claim 11

The system of claim 7 where said means for removing a mixture of excess ink and dampening fluid from said form roller comprises: an ink removal roller urged into pressure indented relation with said form roller; and a doctor blade scraping ink and dampening fluid off of said ink removal roller.

Claim 12

The system of claim 9 with the addition of: a deflector shield positioned to permit gravity feed of excess ink and dampening fluid from said doctor blade to said collection reservoir.

Claim 13

The system of claim 7 said pump means comprising a positive displacement pump.

Claim 14

The system of claim 11, said positive displacement pump comprising: an auger-type screw pump.

Claim 15

The system of claim 7, said collection reservoir comprising: a pan having an inclined bottom sloping towards said means removing ink from a central portion of said collector reservoir.

Claim 16

The system of claim 7, said means metering ink from the surface of the transfer roller onto the surface of the form roller comprising roller means.

Claim 17

The system according to claim 14, said roller means comprising an idler roller in pressure indented relation with said transfer roller and said form roller.

Claim 18

The system according to claim 7, said ink comprising low viscosity letter press-type newsprint ink.

Claim 19

The system according to claim 7, said means sensing the level of ink in the collection reservoir being adapted to maintain a small volume of ink and dampening fluid in a collection reservoir and to cause fresh ink to be added when the level of the small volume falls below a predetermined level.

Claim 20

The system according to claim 7 with the addition of a plurality of printing systems according to claim 7, said pump means being connected to simultaneously deposit ink into a plurality of nips, such that excess dampening fluid from one printing system will be redistributed to a plurality of printing systems.