Adjustable form roll apparatus

1. An apparatus for adjustably positioning a form roll against at least two different sized plate cylinders in a variable cutoff printing unit, the form roll having a form roll axis, the apparatus comprising:

a plate cylinder support for interchangeably supporting the at least two different sized plate cylinders, the plate cylinder support including a plate cylinder bearing housing and a plate cylinder axis, the plate cylinder axis defining a centerline of the plate cylinder, wherein the centerline does not change position, except that the centerline may change position for plate skew or throw-off;

said plate cylinder bearing housing capable of interchangeably supporting at least two different sized plate cylinder cams, the at least two different sized plate cylinder cams including a smaller plate cylinder cam and a larger plate cylinder cam that are removably connectable to the plate cylinder support as alternatives of each other; and

a form roll hanger for supporting the form roll, the form roll hanger being configured for contacting the smaller plate cylinder cam if the smaller plate cylinder cam is coupled to the plate cylinder support to set a smaller distance between the plate cylinder axis and the form roll axis, the form roll hanger being configured for contacting the larger plate cylinder cam if the larger plate cylinder cam is coupled to the plate cylinder support to set a larger distance between the plate cylinder axis and the form roll axis.

2. The apparatus as recited in claim 1 wherein the form roll hanger includes a contact surface for contacting the one of the at least two different sized plate cylinder cams that is supported on the plate cylinder support, the form roll hanger being movable along a predefined path to vary a distance between the plate cylinder axis and the form roll axis.

3. The apparatus as recited in claim 2 further comprising a guide defining the predefined path, the guide controlling movement of the form roll hanger as the contact surface is moved toward and away from the plate cylinder axis.

4. The apparatus as recited in claim 3 wherein the guide is configured such that the predefined path followed by the form roll hanger causes the form roll hanger to be slideable into positions for the contact surface to contact each of the at least two different sized plate cylinder cams as the at least two different sized plate cylinder cams are alternately connected to the plate cylinder support.

5. The apparatus as recited in claim 1 further comprising a vibrator roll, the form roll hanger including a bearing for rotatably supporting the vibrator roll.

6. The apparatus as recited in claim 5 wherein the form roll hanger further includes an eccentric, the eccentric being configured so as to maintain predefined contact pressure between the vibrator roll and the form roll as the form roll axis is moved toward and away from the plate cylinder axis.

7. A variable cutoff printing unit comprising:

the assembly for adjustably positioning a form roll against at least two different sized plate cylinders as recited in claim 1 ;

the at least two different sized plate cylinders, the at least two different sized plate cylinders including a smaller plate cylinder and a larger plate cylinder that are removably connectable to the plate cylinder support as alternatives of each other; and

the form roll, the form roll hanger supporting the form roll;

the form roll hanger being configured such that the smaller plate cylinder contacts the form roll when the smaller plate cylinder and the smaller plate cylinder cam are connected to the plate cylinder support and the smaller plate cylinder cam contacts the form roll hanger, the form roll hanger being configured such that larger plate cylinder contacts the form roll when the larger plate cylinder and the larger plate cylinder cam are connected to the plate cylinder support and the larger plate cylinder cam contacts the form roll hanger.

8. The variable cutoff printing press as recited in claim 7 wherein the form roll hanger includes a contact surface for contacting the one of the at least two different sized plate cylinder cams that is supported on the plate cylinder support, the form roll hanger a predefined path.

9. The variable cutoff printing press as recited in claim 8 wherein the predefined path includes a first position and a second position, the contact surface being at an outer diameter of the smaller plate cylinder cam when a guide portion of the form roll hanger is at the first position, the contact surface being at an outer diameter of the larger plate cylinder cam when the guide portion of the form roll hanger is at the second position.

10. The variable cutoff printing press as recited in claim 9 wherein an outer surface of the form roll is at an outer surface of the smaller plate cylinder when the guide portion of the form roll hanger is at the first position, the outer surface of the form roll being at an outer diameter of the larger plate cylinder when the guide portion of the form roll hanger is at the second position.

11. The variable cutoff printing press as recited in claim 8 wherein the defined path includes a plurality of predefined positions, a contact surface of the form roll hanger being at an outer diameter of one of the at least two different sized plate cylinders when the guide portion of the form roll hanger is at each of the predefined positions.

12. The apparatus as recited in claim 1 further comprising a linear actuator, the linear actuator controlling movement of the form roll hanger as the contact surface is moved toward and away from the plate cylinder axis.