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:
Jun. 02, 1992
Filed:
May. 13, 1991
Thomas W Evans, Houston, TX (US);
Robert G Norell, New Brighton, MN (US);
Stephen A Uban, Stillwater, MN (US);
Richard C Maxson, Maple Grove, MN (US);
Johnson Filtration Systems Inc., New Brighton, MN (US);
Abstract
An underdrain assembly for a bed of filter media includes a plurality of elongated screen lateral elements which each have a generally flat bottom surface and a convexly curved upper surface which has flow openings therein. The lateral elements each have a width substantially greater than their height and include a means defining a generally tubular-shaped surface positioned internally thereof. The generally tubular-shaped surface includes flow distribution openings which have a total open area less than the total area of the flow openings in the curved upper surfaces of the lateral elements. In various embodiments, the generally tubular-shaped surfaces are shown as comprising a single tube, a plurality of tubes, and a tube defined by the portions of a plurality of adjacent channel-shaped members whose leg portions support the curved upper surface of the screen lateral elements.