Alternating current energized printing system utilizing a dielectric covered resilient impression roller

Claim 2

In a system for assisting the transfer of ink, carried on a metal printing cylinder connected to ground potential, to a web of substantially non-conductive material as the web passes along a web path through a nip between the grounded printing cylinder and the outer perimeter of a resiliently covered metal impression cylinder, including the combination of: an electrically conductive inner layer of resilient material on said impression cylinder, means mounting said impression cylinder for rotation on its central axis and insulating said electrically conductive layer of resilient material on said impression cylinder from ground potential, an outer sleeve of dielectric material of homogeneous continuous annular cross section having a width substantially equal to the width of the outer perimeter of the impression cylinder, and having a resistivity substantially greater than that of said conductive layer, and means comprising an electric circuit connected with said electrically conductive layer for applying an electric potential between said electrically conductive layer and said grounded printing cylinder, the entire operative width of the outer perimeter of the impresion cylinder being formed entirely by said dielectric material of said outer sleeve, said dielectric material having a thickness less than 1/8 of an inch and having a dielectric constant between 20 and 100, and said electric circuit comprising an alternating potential source for applying an alternating current electric potential between said electrically conductive inner layer of resilient material and said grounded printing cylinder to produce an alternating reactive current from said electrically conductive inner layer through said dielectric material of said outer sleeve over the entire operative width of said impression cylinder.

Claim 3

A system according to claim 1, with said impression cylinder having an electrically conductive metal core electrically insulated from ground potential and in electrical contact with the inner periphery of said electrically conductive inner layer of resilient material, and said alternating potential source being electrically connected with said electrically conductive metal core for supplying alternating current electrical potential to the interior side of said electrically conductive inner layer and thereby to produce an alternating reactive current through said electrically conductive inner layer and through said dielectric material of said outer sleeve over the entire operative width of said impression cylinder.

Claim 4

A system according to claim 1, with said mounting means for said impression cylinder comprising an electrically conductive shaft mounting said impression cylinder and electrically insulated from ground potential, said alternating potential source being electrically connected with said electrically conductive shaft for supplying alternating current electrical potential to the interior side of said electrically conductive inner layer and thereby to produce an alternating reactive current from said electrically conductive inner layer through said dielectric material of said outer sleeve over the entire operative width of said impression cylinder.

Claim 5

In a system for assisting the transfer of ink, carried on a metal printing cylinder connected to ground potential, to a web of substantially non-conductive material as the web passes along a web path through a nip between the grounded printing cylinder and the outer perimeter of a resiliently covered metal impression cylinder, including the combination of: an electrically conductive layer of resilient material of annular cross section on said impression cylinder, means insulating said electrically conductive layer of resilient material on said impression cylinder from ground potential, an outer sleeve of dielectric material of homogeneous continuous annular cross section forming the outer perimeter of the impression cylinder and disposed directly at said web path for direct contact with the web at said nip over the operative width of said outer perimeter of said impression cylinder, and having a resistivity substantially greater than that of said conductive layer, and means comprising an electric circuit connected with said electrically conductive layer for applying an electric potential between said electrically conductive layer and said grounded printing cylinder, the entire operative width of the outer perimeter of the impression cylinder which is to contact the web being formed entirely by said dielectric material of said outer sleeve, said dielectric material having a thickness less than one-eighth of an inch and having a dielectric constant between twenty and one hundred, and said electric circuit comprising an alternative potential source for applying an alternating current electric potential between said electrically conductive layer of resilient material and said grounded printing cylinder to produce an alternating reactive current from said electrically conductive layer through said dielectric material of said outer sleeve over the entire operative width of said impression cylinder.

Claim 6

In a system for assisting the transfer of ink, carried on a metal printing cylinder connected to ground potential, to a web of substantially non-conductive material as the web passes along a web path through a nip between the grounded printing cylinder and the outer perimeter of a resiliently covered metal impression cylinder, including the combination of: an electrically conductive layer of resilient material of annular cross section on said impression cylinder, means insulating said electrically conductive layer of resilient material on said impression cylinder from ground potential, an outer sleeve of dielectric material of homogeneous continuous annular cross section forming the outer perimeter of the impression cylinder and disposed directly at said web path for direct contact with the web at said nip over the operative width of said outer perimeter of said impression cylinder, and having a resistivity substantially greater than that of said conductive layer, and means comprising an electric circuit connected with said electrically conductive layer for applying an electric potential between said electrically conductive layer and said grounded printing cylinder, the entire operative width of the outer perimeter of the impression cylinder which is to contact the web being formed entirely by said dielectric material of said outer sleeve, said dielectric material having a thickness less than one-eighth of an inch and having a dielectric constant between twenty and one hundred, and said electric circuit comprising an alternative potential source for applying an alternating current electric potential between said electrically conductive layer of resilient material and said grounded printing cylinder to produce an alternating reactive current from said electrically conductive layer through said dielectric material of said outer sleeve over the entire operative width of said impression cylinder.

Claim 7

A system according to claim 4 with said alternating potential source having a metallic conductive path connecting it with the inner periphery of said electrically conductive material of annular cross section for supplying alternating current electrical potential to the interior side of said electrically conductive layer and thereby to produce an alternating reactive current through said electrically conductive layer and through said dielectric material of said outer sleeve over the entire operative width of said impression cylinder.

Claim 8

The system of claim 4 with said outer sleeve of dielectric material having a thickness between about 1/16 inch and about 1/8 inch and a resistivity in the range from about 10 8 ohm-centimeters to about 10 12 ohm-centimeters.