Abstract: A device and method prevents movement of a printing plate during clamping of an end of the plate to an external drum of an imaging system using a clamping apparatus having: a clamping portion disposed on the external drum, wherein the clamping portion may be selectively displaced between a clamping position for clamping the leading edge of the printing plate against the external drum and a release position; and an inflatable member positioned between the clamping portion and the external drum for displacing the clamping portion between the clamping position and the release position. The device includes: a first spring-metal component mounted onto the external drum wherein the end of the plate can be positioned between one end of the first spring-metal component and the external drum, and the first spring-metal component is positioned between the clamping portion and the plate, to prevent the plate from moving during clamping.

Abstract: A nip mechanism for a substrate transfer system includes: a first nip roller; a second nip roller located substantially vertically above the first nip roller; and a drive motor for driving the first nip roller and the second nip roller to feed a substrate between the first nip roller and the second nip roller when the drive motor is driven in a first direction. The second nip roller creates and maintains a nip with the first nip roller due to a force of gravity without using a spring or other mechanical device while the drive motor is driven in the first direction. The drive motor engages a one-way clutch for engaging a roller separation mechanism to raise and separate the second nip roller from the first nip roller when the drive motor is driven in a second direction. The first and second nip rollers maintain substantial vertical alignment with one another when the drive motor is driven in either direction.

Abstract: An apparatus for delivering a printing plate to an external drum platesetter includes: a plate traversing table for displacing a printing plate into a staging position; and a plate angling table, nested within the plate traversing table, for rotating the printing plate between the staging position and a loading position. The plate traversing table includes: a first shaft; a second driven shaft including a plurality of nip rollers; a plurality of pulleys mounted to the first and second shafts; a plurality of rotatable belts, extending between corresponding sets of the pulleys on the first and second shafts; and a drive system for rotating the driven shaft.

Abstract: A nip mechanism for a substrate transfer system allows the nip mechanism to be actuated such as opened and/or closed by the drive motor for the nip mechanism. As a result, the need to operate the nip mechanism pneumatically, for example, can be avoided. Essentially, the drive motor now performs a dual role, i.e., both driving the nip rollers and also opening and closing the nip mechanism. The nip mechanism comprises a roller separation mechanism and a one-way clutch for engaging the roller separation mechanism when the drive motor is driven in the second direction. In the present implementation, this roller separation mechanism comprises a cam that pushes the first nip roller and the second nip roller away from each other. A cam limiter can be used to prevent over-rotation of this cam.

Abstract: A punch assembly is provided with a positive retraction mechanism to remove the punch from the media to be punched, thereby preventing binding of the punch in the media. The punch assembly includes a driving mechanism to provide a driving force on the punch and a positive retraction mechanism disposed to provide a retraction force on the punch operative sequentially following operation of the driving mechanism. The punch assembly, which is of a smaller size and more economical to manufacture, is particularly useful with an imagesetter of a prepress printing system. The punch may be mounted in a cantilever manner to punch the opening as close to the edge of the media as possible without interfering with the laser beam of the imaging assembly. In this maimer, the area of media available for imaging may be maximized and media waste minimized. Additionally, a shaft support mechanism is provided for the shaft upon which the retraction mechanism for each punch is mounted.