US 5,778,781 A · Method and apparatus for printing on opposite sides of a web

Abstract

A continuous web of material is unwound from a roll by driven pull rolls that feed the web material to a printing unit in a feedline of an envelope making machine. The printing unit prints a selected one of the inside surface and the outside surface of the web before the web is cut and folded to form envelopes. The printing unit is supported by a base which is mounted for pivotal movement on a platform of a fixed frame member. The base is connected to the platform by a vertical pivot pin for movement through a 180.degree. between a first position for printing the inside surface of the web and a second position for printing the outside surface of the web. The base of the printer is locked to the platform in the selected one of the first and second positions to perform the desired printing operation. The web is fed between counter-rotating impression and plate cylinders rotatably mounted and driven on the printer base. A film of ink is transferred by an anilox roll on the printer base to the plate cylinder which transfers the inked image to either the inside or outside surface of the web. To reverse the printing to the opposite surface of the web, the printer base is unlocked from the platform and pivoted about the pivot pin to move the plate cylinder to the opposite side of the web. The base is then locked to the platform, and the printing operation is resumed. With this arrangement, a single printing unit is used to print both surfaces of the web material.

Claims20

Dependent claims

A reversible printer for printing both sides of continuous web material comprising,

a support frame having a platform,
a printer base positioned on said support frame platform,
a rotatably driven impression cylinder supported by said printer base,
a rotatably driven plate cylinder supported by said printer base to receive web material fed between said impression cylinder and said plate cylinder for printing,
said plate cylinder having an inked surface for transferring an inked image to one side of the web material, and
said printer base being pivotally mounted on said support frame platform for movement to reverse the position of said impression cylinder and said plate cylinder to print one side of the web material in a first position of said printer base and the opposite side of the web material in a second position of said printer base pivoted from said first position.

3 more elements

A rotary printer for an envelope machine comprising,

a support frame having a platform, said support frame receiving a moving web fed from a source,
a printer base positioned on said support frame platform, said printer base connected to said support frame platform for pivotal movement through 180.degree. between a first position and a second position,
an impression cylinder rotatably supported on said printer base for receiving the moving web on surface of said impression cylinder,
a plate cylinder rotatably supported adjacent to said impression cylinder on said printer base for receiving the web fed between said plate cylinder and said impression cylinder,
an anilox roll rotatably supported in contact with said plate cylinder on said printer base,
a ink distributing mechanism supported by said printer base for transferring a film of ink onto the surface of said anilox roll for transfer to said plate cylinder for printing an image on one side of the web when said printer base is in said first position,
drive means for transmitting rotation from said impression cylinder to said plate cylinder and said anilox roll to transfer an inked image on said plate cylinder to the surface of one side of the web moving between said impression cylinder and said plate cylinder, and
said printer base upon rotation through 180.degree. to the second position on said support frame platform reverses the position of said impression cylinder and said plate cylinder for printing an image on an opposite side of the web.

5 more elements

Dependencies are inferred from the claim text.

Method and apparatus for printing on opposite sides of a web

Life of this patent

Method and apparatus for printing on opposite sides of a web

Life of this patent

Abstract

Claims20