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. 11, 2001
Filed:
Jun. 08, 1999
Akebono Brake Industry Co., Ltd., Tokyo, JP;
Abstract
A drum brake device produces a stable braking force at a predetermined boosting ratio in response to a brake operation force input thereto, even if the friction characteristics of the interface of the brake drum and the brake shoe varies, without increasing the size of the wheel cylinder. The drum brake device includes an input detector that detects a hydraulic braking pressure output from a master cylinder, and produces a signal representative of the detected hydraulic braking pressure as an input force to the drum brake device; an output detector that detects an anchor reaction force generated at the time of braking and produces a signal representative of the detected anchor reaction force as an output force of the drum brake device; electromagnetic valves capable of controlling the supply of a hydraulic braking pressure supplied from the master cylinder to a wheel cylinder; and a control circuit that controls the operations of the electromagnetic valves in accordance with output signals of the input detector and the output detector so that the output force is limited to a force equal to or smaller than a force defined by a predetermined boosting ratio.