Hydraulic pressure modulator

Claim 2

A brake pressure modulator comprising: a housing inclusive of a fluid pressure chamber and a hydraulic cylinder; a pressure responsive wall means in said chamber; spring means to bias said wall means to a normal position in said housing; first and second plungers in said cylinder operatively connected to said wall means and to each other, said first and second plungers defining first and second variable volume chambers in said cylinder and one of same being exposed to pressures of both variable volume chambers, said chambers each having its own inlet and outlet ports; and valve means for said modulator including first valve elements for controlling said pressure responsive means and second valve elements with portions in each fluid inlet with one portion operatively connected to said first plunger and another portion operatively connectEd to said second plunger to control communication between inlet and outlet ports and isolation of same.

Claim 3

The structure of claim 1 wherein said spring means includes two springs to render said modulator fail-safe which two springs are located to maintain the normal position of said plungers in the event of a failure in said pressure responsive means to keep open the communication between inlet and outlet ports.

Claim 4

The structure of claim 1 wherein said valve elements are hydraulically balanced poppets urged to a closed position by spring means that is normally compressed by action of said plungers to maintain said poppets off their seats provided by surrounding structure.

Claim 5

The structure of claim 3 wherein said poppets have a stem of a diameter equal to the seat area therefor and a passage therethrough to equate pressures on all surfaces of said poppet.

Claim 6

The structure of claim 4 wherein a lip seal means is provided on said valve stem permitting return flow from said passage therethrough and blocking flow in the opposite direction.

Claim 7

A brake pressure modulator for use in a braking system, said modulator comprising: a housing including a pressure chamber; movable wall means contained within said pressure chamber, said movable wall means being responsive to a pressure difference thereacross; first and second valve means in said housing for controlling the flow of separate pressurized fluids; first and second plunger means operatively connected to said movable wall means to control said first and second valve means, respectively; means for biasing said movable wall means to a normal position, said normal position allowing flow of said separate fluid pressures through said first and second valve means; and means for controlling said pressure difference across said movable wall means in response to control signals, movement of said movable wall means away from said normal position terminating flow through said first and second valve means by movement of said first and second plunger, respectively, and reducing the pressure of the fluid already delivered through said first and second valve means by further movement of said first and second plungers.

Claim 8

A brake pressure modulator for use in a braking system, said modulator comprising: a housing including a pressure chamber; movable wall means contained within said pressure chamber, said movable wall means being responsive to a pressure difference thereacross; first and second valve means in said housing for controlling the flow of separate pressurized fluids; first and second plunger means operatively connected to said movable wall means to control said first and second valve means, respectively; means for biasing said movable wall means to a normal position, said normal position allowing flow of said separate fluid pressures through said first and second valve means; and means for controlling said pressure difference across said movable wall means in response to control signals, movement of said movable wall means away from said normal position terminating flow through said first and second valve means by movement of said first and second plunger, respectively, and reducing the pressure of the fluid already delivered through said first and second valve means by further movement of said first and second plungers.

Claim 9

The brake pressure modulator, as recited in claim 6, wherein said first plunger has said separate pressurized fluids communicated to opposite ends thereof to equalize pressures delivered through said first and second valve means.

Claim 10

The brake pressure modulator, as recited in claim 6, wherein said controlling means is operated by a first and a second of said control signals, while receiving said first control signal, a first control valve terminates one source of fluid power to said pressure chamber and, upon receiving said second control signal, a second valve establishes another source of fluid power to said pressure chamber to move said movable wall means from its normal position.

Claim 11

In an adaptive braking modulator: a housing defining a bore and a chamber therewithin; said bore being divided into first and second compartments, each of said compartments having an inlet and an outlet port; valve means mounted in each of said compartments for controlling communication between each of said inlet ports and their corresponding outlet ports; pressure differential responsive means slidably mounted in said chamber; plunger means operably connecting said pressure differential responsive means and each of said valve means for operating the latter whereby movement of said pressure differential responsive means in one direction closes said valve means and movement of said pressure differential responsive means in the opposite direction opens said valve means.

Claim 12

In an adaptive braking modulator: a housing defining a bore and a chamber therewithin; said bore being divided into first and second compartments, each of said compartments having an inlet and an outlet port; valve means mounted in each of said compartments for controlling communication between each of said inlet ports and their corresponding outlet ports; pressure differential responsive means slidably mounted in said chamber; plunger means operably connecting said pressure differential responsive means and each of said valve means for operating the latter whereby movement of said pressure differential responsive means in one direction closes said valve means and movement of said pressure differential responsive means in the opposite direction opens said valve means.

Claim 13

The invention of claim 9: said plunger means including an element operating one of said valve means; said element having a pair of opposed faces, one of said faces being exposed to the fluid pressure level in one of said compartments, the other face of said element being exposed to the flUid pressure level in the other compartment.

Claim 14

The invention of claim 10: said bore including a cavity, opposite faces of said element being exposed to the fluid pressure level in said cavity and in one of said compartments; said plunger means including a member extending from said cavity into the other chamber.

Claim 15

The invention of claim 9: said bore including a cavity; said plunger means including a rod-like member operatively engaging said pressure differential responsive means and extending into said cavity, an element having a pair of opposed faces exposed to the fluid pressure level in said cavity and in one of said compartments, said rod-like member engaging the face of said element exposed to the fluid pressure level in said cavity, and a member operatively connected to said rod-like member and extending from said cavity into the other chamber.