Patent ID: 7159696

Claim:
A hydraulic braking pressure generating apparatus for vehicles, comprising: a first piston member moved back and forth in response to operation of a manually operated braking member; an elastic member for providing a stroke of said first piston member in response to braking operation force of said manually operated braking member; a second piston member slidably accommodated in a cylinder housing for defining a master pressure chamber in front of said second piston member, and defining a simulator chamber behind said second piston member and in front of said first piston member, said second piston member being moved back and forth in response to the braking operation force of said manually operated braking member transmitted to said second piston member through said first piston member and said elastic member; an atmospheric pressure reservoir for storing brake fluid under atmospheric pressure; changeover means for selectively providing a communicating state for communicating said simulator chamber with said atmospheric pressure reservoir, and a cut-off state for blocking the communication between said simulator chamber and said atmospheric pressure reservoir; and stroke restriction means for restricting a maximal stroke of said first piston member relative to said cylinder housing to be smaller than the sum of a maximal stroke of said second piston member relative to said cylinder housing and a maximal stroke of said first piston member relative to said second piston member.