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:
Oct. 24, 1990
Mauri Koivuranta, Petajavesi, FI;
Valmet Paper Machinery Inc., , FI;
Abstract
A gap former in a paper machine, comprising a lower wire loop (10) and an upper wire loop (20), which together define a substantially horizontal twin wire forming zone, which comprises the following web forming zones (a), (b) and (c): (a) In the area of the forming gap (G), a first suction zone (11a) placed inside the first forming roll (11), and immediately thereafter a second suction zone (11b) is placed in forming roll (11). The suction zones (11a, 11b) are placed in the first upper quarter of the first forming roll (11) at the side of the forming gap (G). The levels of negative pressure (P.sub.1, P.sub.2) in the suction zones are adjustable. (b) A forming shoe (12), which is provided with an open guide deck (26), the interior space in the shoe being divided into at least two subsequent suction chambers (12a, 12b, 12c), the levels of negative pressure (P.sub.a, P.sub.b, P.sub.c) effective in said suction chambers being arranged to be adjustable, preferably separately adjustable. (c) Web-formation and/or guide members (13a, 13b, 17, 25) arranged after the forming shoe (12), the members guiding the twin wire zone downwards.