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:
Apr. 24, 1990
Filed:
Oct. 19, 1988
Frey A Frejborg, Glens Falls, NY (US);
A. Ahlstrom Corporation, Karhula, FI;
Abstract
A plurality of blind openings (e.g. holes or slots) are formed through a first face of a steel plate and extend a predetermined distance short of the opposite face. Larger size openings are formed through the first face using the blind openings as pilot openings. The larger size openings extend into the plate short of the terminations of the blind openings. Metal is machined from the opposite face in parallel rows defining grooves and to a depth to uncover the terminations of the blind openings in the plate body thereby providing through-extending screen openings in the plate. The ridges (bars) between the grooves may be quadrate in cross-section, or a side face sloped (angled) by machining. A screen cylinder with bars of the invention has a maximum screen area (compared to prior art screens with bars).