US Patent 7735393 Brake pedal apparatus

A brake pedal apparatus including: (a) an operating pedal disposed pivotably about a first axis; (b) a pivot member disposed pivotably about a second axis and connected to the operating pedal via a link mechanism so as to be pivoted about the second axis in response to a depressing operation of the operating pedal; and (c) an output member for receiving an output generated by pivot motion of the pivot member. The link mechanism includes (i) a first connecting link connecting the operating pedal and the pivot member with first play, and (ii) a second connecting link connecting the operating pedal and the pivot member with second play. In a first region before a characteristic switching point of a pedal stroke of the operating pedal, the pivot member is pivoted through the first connecting link, while a lever ratio is changed according to a first lever ratio characteristic. In a second region beyond the characteristic switching point, the pivot member is pivoted through the second connecting link, while the lever ratio is changed according to a second lever ratio characteristic.