摘要 |
An adjustable force driving nip assembly for use in a sheet transport system of a document creating apparatus has a plurality of adjustable force driving nips aligned and spaced transversely across the sheet travelling path of the sheet transport system. Each driving nip has a spring biased idler roller mounted on a cam follower and mated with a driven roller. The spring bias produces a normal force for the idler roller that urges the idler roller against the driven roller. A stepper motor is adapted to interact concurrently with the cam followers and, upon actuation, vary the force of the spring thus adjusting the normal force of the idler rollers. A controller actuates the stepper motor in response to sheet media data entered into a control panel of the document creating apparatus by an end user, thereby automatically adjusting the normal force of the idler rollers to prevent sheet marking.
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