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:
Dec. 31, 2024
Filed:
Mar. 02, 2022
Kabushiki Kaisha Pilot Corporation, Tokyo, JP;
Hisatoshi Hayakawa, Tokyo, JP;
Kabushiki Kaisha Pilot Corporation, Tokyo, JP;
Abstract
A friction unit includes a friction piece and a retention portion, the friction piece being configured to allow generation of frictional heat to cause handwriting in thermochromic ink to undergo a thermochromic change and the retention portion being configured to allow retention of the friction piece and attachment to and detachment from a barrel or cap of a thermochromic writing instrument. The retention portion has a tubular side wall forming an internal space opening at least downward, the side wall has at least one vent hole formed to communicate with the internal space, and air is allowed to flow between the vent hole, the internal space, and the downward opening.