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DIFFERENTIAL MOTOR SCAN DRIVE SYSTEM

IP.com Disclosure Number: IPCOM000025158D
Original Publication Date: 1983-Dec-31
Included in the Prior Art Database: 2004-Apr-04
Document File: 4 page(s) / 131K

Publishing Venue

Xerox Disclosure Journal

Abstract

A scan drive system to allow complete variation in the speed of a scan carriage of a copier in both forward and reverse directions. Full stopping of the carriage is also provided without stopping or reversing of the drive motor or declutchinq or shifting of the drive gears.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 57% of the total text.

Page 1 of 4

A 'EROX DISCLOSURE JOURNAL

DIFFERENTIAL MOTOR SCAN DRIVE SYSTEM
Thomas E. Potter

Proposed Classification
U.S. Cl. 74/25 Int. C1. F16h 21/16

8

.

Volume 8 Number 6 November/December 1983 459

[This page contains 1 picture or other non-text object]

Page 2 of 4

DIFFERENTIAL MOTOR SCAN DRIVE SYSTEM (Cont'd)

A scan drive system to allow complete variation in the speed of a scan carriage of a copier in both forward and reverse directions. Full stopping of the carriage is also provided without stopping or reversing of the drive motor or declutchinq or shifting of the drive gears.

Referring to the drawing figure, the system consists of an endless drive belt 3 formed into top and bottom loops 4,5, respectively. An interior drive pulley 6 is provided at any point within the top loop 4 with a second interior drive pulley 7 at any point within the bottom loop 5. Drive pulleys 6,7 are driven either directly or through gears by drive motors 8,9, respectively. One or more interior indler pulleys 11,12 are provided in each of the top bottom loops 4, 5 to complete the loops. A pair of exterior pulleys 14,15 between loops 4,5 are rotatably attached to the scan carriage 16.

Where drive pulleys 6,7 are driven at speeds such that the pulley surface velocities are equal, scan carriage 16 is stationary. If pulleys 6,7 are driven at speeds such that the surface velocity of pulley 6 is greater than the surface velocity of pulley 7, then scan carriage 16 moves in the direction shown by the solid line arrow. And, where pulleys 6,7 are driven at speeds such that the surface velocity of pulley 7 is greater than the surface velocity of pulley 6, scan carriage 16 moves in the opposite direction as shown by the dotted line arrow.

The instantaneous velocity (Vc) of scan carriage 16 is given by the following relationship:

vc = K(r2 w2 - r w ); where

r1 = the radius of drive pulley 6

r2 = the radius of drive pulley 7

w1 = angular velocity of drive pulley 6

w2 = angular velocity of drive pulley 7

Since the speed of scan carriage 16 is dependent only on the difference between the surface velocities of drive pulleys 6,7 drive motors 8,9 can operate at any speed which permits the user to select carriage operating speed without regard to carriage motion. Thus, detrimental frequencies may be avoided. And, since the apparent stiffness of the drive belt 4 increases as the square of its velocity, drive line stiffness can be easily maintained even during low speeds of scan carriage 16....