US 4,443,094 A · Duplicating machine with duplexing capability

Abstract

In a duplicating machine for duplicating images on both sides of copy sheets including a blanket cylinder and an impression cylinder, a mechanism for handling the sheets and re-feeding the sheets back to the impression cylinder for duplex copying. The blanket cylinder has first and second images transferable to the copy sheets. The impression cylinder forms a nip with the blanket cylinder for transferring the copy sheets through the nip. A first gripper on the impression cylinder releasably engages a lead end of a copy sheet and moves the sheet through the nip to transfer the first image on a first side of the sheet. A chain gripper releasably engages the lead end of the sheet transferred thereto by the first gripper and transports the sheet away from the impression cylinder. A swing gripper releasably engages a trail end of the sheet in timed relation with release of the sheet by the chain gripper and re-feeds the sheet back to the impression cylinder. A second gripper on the impression cylinder releasably engages the trail end of the sheet and moves the sheet through the nip to transfer the second image to a second side of the sheet.

Claims23

Dependent claims

In a duplicating machine for duplicating images on both sides of copy sheets including a blanket cylinder having first and second images transferable to the copy sheets, an impression cylinder forming a nip with the blanket cylinder and for supporting and transferring the copy sheets through the nip, and means for feeding copy sheets to the impression cylinder, means for handling said sheets for duplexing said images thereon comprising:

first gripper means on said impression cylinder for releasably engaging a lead end of a copy sheet and moving the sheet through said nip to transfer the first image to a first side of the sheet;
transport gripper means for releasably engaging the lead end of the sheet transferred thereto by said first gripper means and transporting the sheet in a direction away from the impression cylinder;
swing gripper means for releasably engaging a trail end of the sheet in timed relation with release of the sheet by said transport gripper means and re-feeding the sheet back to the impression cylinder;
and
second gripper means on the impression cylinder for releasably engaging said trail end of the sheet and moving the sheet through the nip to transfer the second image to a second side of the sheet.

2 more elements

In an offset duplicating machine including a blanket cylinder having a first and a second image transferable to a copy sheet, an impression cylinder for supporting a copy sheet during transfer of the first and the second image to the sheet and means for feeding copy sheets to the impression cylinder, the improvement of a duplexing apparatus comprising:

first gripper means on the impression cylinder operable from an open position to a closed position for releasably engaging a lead end of the sheet to hold the sheet during transfer of the first image to a first side of the sheet;
chain gripper means operable from an open position to a closed position for releasably engaging the lead end of the sheet in timed relation with the opening of the first gripper means for transferring the lead end of the sheet to the chain gripper means and transporting the sheet in a direction away from the impression cylinder;
swing gripper means operable between an open position and a closed position for releasably engaging a trail end of the sheet;
means for operating the chain gripper means to the open position for releasing the lead end of the sheet to permit the swing gripper means to engage the trail end of the sheet;
means for operating the swing gripper means to the closed position for engaging the trail end of the sheet released by the chain gripper means in response to the swing gripper means being in a first position, for actuating the swing gripper means from the first position to a second position for transporting the sheet to a second gripper means associated with the impression cylinder, and for operating the swing gripper means to the open position for releasing the trail end of the sheet for transfer to the second gripper means in response to the swing gripper means being in the second position;
said second gripper means being operable from an open to a closed position for releasably engaging the trail end of the sheet to hold the sheet during transfer of the second image to a second side of the sheet.

3 more elements

Dependencies are inferred from the claim text.

Duplicating machine with duplexing capability

Life of this patent

Duplicating machine with duplexing capability

Life of this patent

Abstract

Claims23