Browse Prior Art Database

CONFIGURATION FOR MINIMIZING FUSER THUMP

IP.com Disclosure Number: IPCOM000026612D
Original Publication Date: 1992-Dec-31
Included in the Prior Art Database: 2004-Apr-06
Document File: 2 page(s) / 69K

Publishing Venue

Xerox Disclosure Journal

Abstract

The present disclosure is directed toward providing a low-cost means for eliminating speed variations caused by paper entering a high pressure nip. As copy sheets move along the paper path of a reprographic machine, there exists different load conditions that cause abrupt changes in the drive motor torque. These changes are classified as torque spikes and are characterized as having a very fast rate of increase that approximates a 25 to 50% rise in torque. Consequently, a torque spike can cause the speed of a drive system to vary, thereby causing problems for other subsystems along the paper path.

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XEROX DISCLOSURE JOURNAL

CONFIGURATION FOR Proposed Classification MINIMIZING FUSER THUMP U.S. C1.355/282 Robert M. Simms
Int. James R. Simpson C1. G03g 15/20

The present disclosure is directed toward providing a low-cost means for eliminating speed variations caused by paper entering a high pressure nip.

As copy sheets move along the paper path of a reprographic machine, there exists different load conditions that cause abrupt changes in the drive motor torque. These changes are classified as torque spikes and are characterized as having a very fast rate of increase that approximates a 25 to 50% rise in torque. Consequently, a torque spike can cause the speed of a drive system to vary, thereby causing problems for other subsystems along the paper path.

Torque developed by any electric motor is a function of the annateur current and the flux density surrounding the resultant magnetic field. The corresponding inductance of the armateur winding prohibits any instantaneous changes in motor torque that will compensate for the spikes. Therefore, it is proposed to skew the rolls, in a high pressure nip, relative to an advancing sheet of paper so that the rate of rise of a torque spike is well within the capabilities of the drive motor.

REFERENCES
U.S. Patent No. 4,378,152 to Edwards et al. discloses a skewed approach orientation of the leading edge of a paper to a fusing nip. The sheet is introduced in a manner such that the sheets initial contact to a hot roll fuser i...