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:
May. 18, 1993
Filed:
Oct. 19, 1992
Walter Jozat, Bad Bramstedt, DE;
Steffen Wunsche, Hamburg, DE;
Ronald Broers, Hamburg, DE;
Thomas Hentze, Hamburg, DE;
Horst Eising, Hamburg, DE;
rotring-werke Riepe KG, Hamburg, DE;
Abstract
A writing or drawing instrument wherein a housing (1), is provided with a writing point (2) and a writing fluid reservoir (3) within an interior space of the housing. A capillary pressure equalization system (5), that connects the reservoir with the ambient air, has a sensor (7) therein for reacting to the level of writing fluid (4) therein. A suction pump (11, 12) is connected with the writing fluid reservoir (3) through a semi-permeable membrane (10) which lets air through and is impermeable for writing fluid (4). The suction pump (11, 12) is activated by the sensor (7) in response to a level of writing fluid (4) in the pressure equalization system, and aspirates air from the reservoir so as to quickly reduce an overpressure condition.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile