Dual area brake actuation piston mechanism

A dual area brake actuation piston mechanism, comprising a housing having therein first and second bores, the second bore disposed within and coaxial with said first bore, a first piston disposed in said first bore and extending from the bore to a piston end, a second piston disposed within said second bore and extending to said piston end, respective first and second bore openings in the housing to permit fluid flow communication with said bores, the second bore opening containing valving means which controls fluid flow into said second bore wherein said valving means comprises poppet valve means which opens at a predetermined fluid pressure to permit fluid pressure through said second bore opening to said second bore, and an adjuster mechanism disposed within the second bore, so that fluid pressure communicated with said bore openings causes said first piston to displace said piston end and increased fluid pressure causes said second piston to be displaced against said piston end such that the piston end is displaced conjointly by both pistons.

A dual area brake actuation piston mechanism, comprising a housing defining separately therein first and second bores substantially isolated from one another, the second bore disposed within and coaxial with said first bore, a first piston disposed in said first bore and extending exteriorly from the housing and first bore to a piston end, a second piston disposed within said second bore and extending exteriorly to said piston end, the pistons each attached fixedly to the piston end, a manifold chamber defined only by the housing and communicating with respective first and second bore openings in the housing to permit fluid flow communication with said bores, and the second bore opening containing valving means which controls fluid flow into said second bore, so that fluid pressure communicated with said bore openings causes said first piston to displace said piston end and increased fluid pressure causes said second piston to be displaced against said piston end such that the piston end is displaced conjointly by both pistons.

A dual area brake actuation piston mechanism, comprising a housing defining separately therein first and second bores substantially isolated from one another, the second bore disposed within and coaxial with said first bore, a first piston disposed in said first bore and extending exteriorly from the housing and first bore to a piston end, a second piston disposed within said second bore and extending exteriorly to said piston end, the piston end including an axial extension extending into the second bore and slidingly engaging an axial extension of the second piston, the extensions engaging so as to permit the passage of atmosphere therepast, a manifold chamber defined only by the housing and communicating with respective first and second bore openings in the housing to permit fluid flow communication with said bores, and the second bore opening containing valving means which controls fluid flow into said second bore, so that fluid pressure communicated with said bore openings causes said first piston to displace said piston end and increased fluid pressure causes said second piston to be displaced against said piston end such that the piston end is displaced conjointly by both pistons.