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. 19, 2022
Filed:
Mar. 04, 2019
Applicant:
Kotobuki & Co., Ltd., Kawagoe, JP;
Inventors:
Hidehei Kageyama, Kawagoe, JP;
Takeshi Wakayama, Kawagoe, JP;
Assignee:
KOTOBUKI & CO., LTD., Kawagoe, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B43K 21/16 (2006.01); B43K 21/22 (2006.01);
U.S. Cl.
CPC ...
B43K 21/16 (2013.01); B43K 21/22 (2013.01);
Abstract
A mechanical pencil includes a writing lead, a chuck unit for chucking the writing lead, and a cushion spring configured to elastically support the chuck unit in such a manner that the chuck unit is retractable with a writing pressure. An output of the cushion spring, in response to a cushion stroke, is non-linear, and a slope of a spring constant, in a region where the cushion stroke is relatively small, is smaller than a slope of a spring constant in a region where the cushion stroke is relatively large.