The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 24, 2002
Filed:
Apr. 14, 1999
Matias Negatu, Vancouver, WA (US);
Szymon Morawski, Vancouver, WA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
An apparatus and method for picking and feeding a single sheet from a stack. A pick roller and a retard roller are held together in a pick assembly, and positioned so that the pick roller is in contact with the top surface of the top sheet and adjacent a leading edge of the top sheet. The pick roller is driven to pick a sheet from the stack, pulling the sheet into the nip between the pick roller and the retard roller. The retard roller applies a retard force to the retard roller tending to resist the rotation of the retard roller as print media is driven into the nip during a pick operation. The retard force is less than a feed force applied to the top sheet by the pick roller as the top sheet is passed into the nip, the retard force being greater than a sheet-to-sheet frictional drag force between the top sheet and an adjacent sheet, thereby separating an adjacent sheet from the top sheet to prevent multiple sheet picks. The retard force is applied by a torque limiter incorporated in the retard roller structure. A suspension apparatus is coupled to the pick roller and retard roller assembly for permitting the assembly to move through a range of movement as the height of the media stack changes due to repeated pick operations, such that the pick roller is in contact with the top sheet for media stacks of varying heights.