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. 20, 2011
Filed:
Oct. 06, 2009
Hirofumi Morishita, Seto, JP;
Hirofumi Morishita, Seto, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota-Shi, JP;
Abstract
The friction engagement apparatus comprises a case forming part of a power transmission apparatus, a plurality of friction plates splined to the case, a plurality of friction plates splined to a rotation element, an annular piston having a cylindrical wall portion imparting the urging pressure to the friction plates, an urging device having a return spring intervening between the case and the piston to urge the piston in one axial direction, the cylindrical wall portion having a first pressure receiving section formed with a cut-off recession, and a second pressure receiving section formed with no cut-off recession, and the return spring being coaxially arranged with the piston and having a bending stiffness in the axial direction with respect to a circumferential unit length, the bending stiffness in the first pressure receiving section being larger than the bending stiffness in the second pressure receiving section.