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:
Aug. 19, 2025
Filed:
Feb. 07, 2023
Tpr Co., Ltd., Tokyo, JP;
TPR Co., Ltd., Tokyo, JP;
Abstract
A piston unit adapted to reciprocate in a cylinder includes a piston and a top land member attached to the piston. The piston includes a first portion including a piston end at one end surface side and fitted with the top land member. The first portion has a smaller outer diameter than a second portion such that there is a step therebetween. The second portion is the other portion of the piston than the first portion. The top land member has a groove wall forming surface opposed to a step surface that connects the outer circumferential surface of the first portion and the outer circumferential surface of the second portion. The first ring groove is defined by the groove wall forming surface, the step surface, and the outer circumferential surface of the first portion.