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:
Jul. 29, 2003
Filed:
Jan. 28, 2002
Nikolaus Brugner, Ziemetshausen, DE;
Sulzer Chemtech AG, Winterthur, CH;
Abstract
The invention relates to a ventilation device for a piston for a cartridge. The ventilation device includes a first piston part which rests sealingly against the cartridge wall and a second piston part, which forms a valve with the first piston part. The valve opens when a pressure is exerted on the rear side of the piston so that the air is trapped between the filling composition and the piston can escape. According to the invention, a filter section is provided in front of the valve, between the two piston parts, as seen from the flow path of the air through the valve. This filter section has at least one narrow channel which forms a penetration barrier for the filling mass and ensures that the valve remains dry and free of dirt.