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:
May. 15, 1990
Filed:
Apr. 08, 1988
Masahiro Ohkubo, Kadoma, JP;
Kabushiki Kaisha Daiken Seisakusho, Neyagawa, JP;
Abstract
A lock-up device for a torque converter, in which a piston actuated by hydraulic force and a lock-up damper are disposed between a front cover and a turbine wheel of the torque converter, a pressing force of the piston causes both friction surfaces of a friction plate of the lock-up damper to press on a friction plate of the front cover, and plural hydraulic chambers are provided by forming a pressure surface of the piston into a multiple-stage structure. A hydraulic chamber located at the most inner peripheral side is connected to a passage of hydraulic oil. The plural hydraulic chambers are connected with each other through fine clearances. A pressure area of the piston in the most inner peripheral side hydraulic chamber is set to a size which does not permit the piston to press on the front cover side friction plate under a state where the hydraulic oil is filled only in the most inner hydraulic chamber.