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. 04, 1999
Filed:
May. 30, 1997
Aisin Seiki Kabushiki Kaisha, Kariya, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
The invention is directed to a hydraulic brake apparatus which includes a master cylinder having a cylinder body and a master piston slidably disposed therein for defining a pressure chamber ahead of the master piston and a power chamber behind the master piston. The master piston includes a first piston connected to a brake pedal and a second piston slidably disposed relative to the first piston. The rear ends of the first piston and second piston are exposed to the power chamber, and the front ends of the first piston and second piston are exposed to the pressure chamber. An engaging member is provided for engaging the second piston with the first piston upon forward movement of the second piston. A control piston is slidably disposed in the cylinder body ahead of the master piston to define the pressure chamber behind the control piston. An auxiliary pressure source is provided for pressurizing brake fluid to generate a power pressure, and a valve assembly is communicated with the auxiliary pressure source to regulate the power pressure into a regulated pressure in response to movement of the control piston. The valve assembly is adapted to supply the regulated pressure into the power chamber to assist the operation of the manually operated member.