Patent ID: 6877416
Filing Date: 2005-04-12
Classification: B60T

Abstract:
1. A braking force amplifier with dual amplification ratios comprising: a piston operated by a pressure differential between a front chamber and a back chamber, the piston comprising a first piston bearing surface coaxial with a second piston bearing surface; a plunger operably attached to a brake pedal and axially displaceable within the piston to control the pressure differential; a thrust assembly comprising a reaction rod, operably connected to a master-cylinder and mounted to be axially displaceable under control of the plunger between a first braking state and a second braking state, the reaction rod further including a flat head mounted to be axially displaceable within a sleeve; a deformable reaction disc formed of a deformable material and interposed between the piston and the flat head, said reaction disc disposed within the sleeve and held within the sleeve by an annular flange, the flange including a central orifice for receiving the piston and forming a sleeve bearing surface axially separated from the second piston bearing surface when the assembly is in the first braking state and the sleeve bearing surface not axially separated from the second piston bearing surface when the assembly is in the second braking state, and wherein movement of the assembly from the first braking state to the second braking state deforms the reaction disc to cause displacement of the deformable material into the region within the sleeve about the piston.