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. 05, 1983
Filed:
Jun. 30, 1981
Hans-Dieter Rosel, Altdorf, DE;
J. S. Staedtler KG, Nuremberg, DE;
Abstract
An apparatus for supplying a liquid writing medium to the writing unit of a writing or drawing device has a writing unit connected by a flow line to a dip tube in a container for a liquid writing medium. The bottom of the container is located in substantially the same horizontal plane as the writing tip of the writing unit. From a suitable source, air is supplied under pressure to the surface of the writing medium within the container. The surface area of the writing medium within the container is greater than the surface area of the writing medium within the writing unit. A regulating valve connected between the container and source of air under pressure regulates the flow of liquid writing medium by supplying writing medium when the writing unit is operative and interrupting the writing medium when the writing unit is nonoperative.