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:
Jan. 01, 1991
Filed:
Dec. 07, 1989
Gerald Grotsch, Furth, DE;
Karl Kaiser, Wendelstein, DE;
J. S. Staedtler GmbH & Co., Nuremberg, DE;
Abstract
Apparatus for screwing a writing instrument tip into a writing fluid reservoir in a writing instrument in which the connection from the reservoir to the tip, in order to supply the writing fluid to the tip, is made by the screwing action just prior to using the writing instrument, in which the writing instrument tip has at least a first working surface upon which at least a second working surface of a wrench acts, the working surfaces being formed as a ratchet and pawl which only engage in a screwing direction and permitting a relative rotation of the working surfaces in an unscrewing direction. As a result the tip cannot be unscrewed from the writing fluid reservoir, avoiding contamination, air entry or blockages.