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:
Dec. 24, 1991
Filed:
Sep. 11, 1990
Robert R Wells, Phoenix, MD (US);
Boyce C Dent, Mountville, PA (US);
Ward Holding Company, Inc., Wilmington, DE (US);
Abstract
A lead edge sheet feeder, particularly for corrugated paperboard sheets, has an endless belt transfer section downstream of a control gate. This endless belt is driven at constant speed and at least first and second vacuum boxes are disposed successively along the transfer belt. Both vacuum boxes are continuously connected to a vacuum source. Each vacuum box has an open face which has to be completely covered by the sheet being fed before that vacuum box is effective in drawing the sheet against the transfer belt. There may be a third vacuum box, and vent holes may be provided in a common partition between the third and second vacuum boxes. The feed section, upstream of the control gate, may have modes for long and short sheets, in the shorter sheet mode less length of sheet being contacted by a feed conveyor. Another lead edge feeder has pull rolls as the transfer section in conjuction with a control system for maintaining feeding of each sheet by the feed section until a leading crease line in the sheet has passed downstream of the nip of these pull rolls. Crushing of corrugated sheets is eliminated or reduced by various embodiments.