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. 16, 2000
Filed:
Jun. 30, 1998
Michiharu Nishii, Toyota, JP;
Masaki Oishi, Toyota, JP;
Kyousuke Hata, Toyota, JP;
Hideki Yamamoto, Anjo, 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. A master piston is received in a cylinder body to define a pressure chamber ahead of the master piston and a power chamber behind it. An auxiliary pressure source is provided for pressurizing the brake fluid in a reservoir to discharge power pressure. A control piston is slidably disposed in the cylinder body ahead of the 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 the pressure chamber. A first passage is adapted to communicate the auxiliary pressure source with the power chamber, and a second passage is adapted to communicate the power chamber with the reservoir through the regulator chamber. A pressure increase valve device is disposed in the first passage to open or close the first passage in response to movement of the control piston. And, a pressure decrease valve device is disposed in the second passage to open or close the second passage in response to movement of the control piston. Preferably, a one way valve is disposed in the first passage, and a pressure restriction device may be disposed in the second passage.