Printing Assembly

• US 20080264283A1
• Filed: 04/26/2007
• Published: 10/30/2008
• Est. Priority Date: 04/26/2007
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Tzori, Gilad, Taig, Elad, Abbo, Haggai, Goldenstein, Zohar
• Granted Patent: US 9,547,271 B2
• Time in Patent Office: Days
• US Class Current: 101/375
• CPC Class Codes: B41F 13/10 Forme cylinders
• CPC Class Codes: B41F 33/00 Indicating, counting, warning, control or safety devices arrangements of counting devices in platen presses B41F1/00 , B41F1/58; arrangements of counting devices in cylinder presses B41F3/84; ink supply or metering devices B41F31/02
• CPC Class Codes: B41F 5/00 Rotary letterpress machines office printing machines B41L15/00
• CPC Class Codes: B41F 9/08 Wiping mechanisms
• CPC Class Codes: G03G 15/757 Drive mechanisms for photosensitive medium, e.g. gears

Abstract

The present invention provides a printing assembly which includes a printing drum such as an impression drum, a pair of eccentric bearings between and on which the drum is mounted for rotation, a pair of self aligning bearings on which the eccentric bearings are supported, and a pair of frameless motors directly connected to the eccentric bearings in order to effect the rotation thereof through closed loop feedback control, in order to facilitate the automatic and accurate control of pressure level and uniformity along the nip of a printing press.

Claims

1. A printing assembly comprising a drum;

a pair of eccentric bearings between and on which said drum is mounted for rotation;

a pair of drives to effect independent rotation of the eccentric bearings; and

a closed loop control circuit actuating the drives in response to torque based feedback from the drives.

2. A printing assembly according to claim 1 comprising a pair of self-aligning bearings, each eccentric bearing being mounted within one of said self-aligning bearings, said pair of drives effecting rotation of said eccentric bearings on said self-aligning bearings.

3. A printing assembly according to claim 1 in which each drive is rigidly coupled to the respective eccentric bearing.

4. A printing assembly according to claim 3 in which each drive is positioned concentrically with the respective self-aligning bearing.

5. A printing assembly according to claim 1 in which said torque based feedback is derived from the electric current drawn by the drives.

6. A printing assembly according to claim 1 in which each drive comprises a frameless motor.

7. A printing assembly according to claim 1 in which each eccentric bearing comprises an outer casing and an inner bearing mounted eccentrically within said outer casing.

8. A printing assembly according to claim 7 in which each drive is rigidly coupled to said outer casing of the respective eccentric bearing.

9. A printing assembly according to claim 2 in which each eccentric bearing comprises an outer casing and an inner bearing mounted eccentrically within said outer casing, said outer casing of each eccentric bearing being mounted concentrically within the respective self-aligning bearing.

10. A printing assembly according to claim 2 in which each self-aligning bearing comprises a spherical roller bearing.

11. A printing assembly according to claim 7 in which said inner bearing comprises a cylindrical roller bearing.

12. A printing assembly according to claim 1 comprising a pair of encoders, each of said drives having one of said encoders in operative association therewith and operable to indicate the rotational position of said drive.

13. A printing assembly according to claim 7 in which each drive comprises a frameless motor having a rotor directly coupled to said outer casing of the respective eccentric bearing.

14. A printing assembly according to claim 2 comprising a housing on either side of said drum, each housing enclosing the respective eccentric bearing and self-aligning bearing;

and in which assembly each drive comprises a frameless motor having a stator housing rigidly connected to the respective housing.

15. A printing assembly comprising a drum;

a pair of bearings on which said drum is mounted for rotation and each of which facilitate the radial displacement of a respective end of said drum;

a pair of drives operable to effect the independent displacement of each end of said drum;

a closed loop control circuit actuating the drives in response to torque based feedback from the drives;

wherein each drive is directly connected to the respective bearing.

16. A printing assembly comprising a first drum and a second drum between which is defined a nip;

a pair of eccentric bearings between and on which said first drum is mounted for rotation;

a pair of self-aligning bearings, each eccentric bearing being mounted within one of said self-aligning bearings;

a pair of drives to effect independent rotation of the eccentric bearings on the self-aligning bearings in order to vary the pressure along the nip; and

a closed loop control circuit actuating the drives in response to torque based feedback from the drives.