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:
Nov. 29, 1983
Filed:
Jun. 22, 1981
Joseph R Hilton, Surrey, GB;
John D Wood, Hertfordshire, GB;
Racal Safety Limited, Middlesex, GB;
Abstract
The present invention relates to a filtering facepiece made from flexible filtering sheet material. The facepiece is made from a flat pocket 100 of filtering sheet material having opposed side walls 105 and 106, a generally tapering shape with an open end 104 at the larger end and a closed end 101 at the smaller end. The edge of the pocket at the closed end is outwardly bowed, e.g. defined by intersecting straight lines and/or curved lines, and the closed end is provided with fold lines 107 defining a surface which is folded inwardly of the closed end of the pocket to define a generally conical inwardly extending recess 108 for rigidifying the pocket against collapse against the face of the wearer on inhalation.