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:
Jul. 18, 2000
Filed:
Jun. 30, 1998
Michiharu Nishii, Toyota, JP;
Masaki Oishi, Toyota, JP;
Aisin Seiki Kabushiki Kaisha, Kariya, JP;
Abstract
The present invention is directed to a hydraulic brake apparatus for applying braking force to each wheel of a vehicle in response to depression of a brake pedal. An auxiliary pressure source is provided for pressurizing the brake fluid in the reservoir to discharge power pressure. A control piston is slidably disposed in a cylinder body ahead of a master piston to be movable in response to movement thereof, so that a regulator chamber is defined ahead of the control piston, and a rear end thereof is exposed to a pressure chamber. A pressure increase valve is provided for communicating the regulator chamber with the auxiliary pressure source or cutting off the communication in response to movement of the control piston. A pressure decrease valve is provided for communicating the regulator chamber with the reservoir or cutting off the communication in response to movement of the control piston. A resilient member is disposed in the cylinder body for defining a counter-force chamber into which pressure is fed from one of the pressure chamber, auxiliary pressure source and power chamber. The resilient member is adapted to activate the pressure increase and decrease valves to move in a direction opposite to a direction thereof moved by the control piston. A pressure control valve is controlled in response to driving and/or braking conditions of the vehicle to vary the pressure in the counter-force chamber continuously thereby to be regulated into a predetermined pressure.