Antiskid brake system with power assistance

Claim 2

An antiskid brake system with power assistance comprising: a source of assist power; at least one wheel brake cylinder; at least one activating cylinder having one end thereof connected to said wheel brake cylinder; a master cylinder connected to said source, said master cylinder including a driver actuated control valve to connect assist power to one end of said master cylinder; a first hydraulic connection connected to said one end of said master cylinder and the other end of said activating cylinder to supply assist power to said activating cylinder upon actuation of said control valve to actuate said wheel brake with said assist power; a second hydraulic connection connected to the other end of said master cylinder and to said activating cylinder spaced from said other end of said activating cylinder to enable a driver to supply brake power to said activating cylinder to activate said wheel brake cylinder upon failure of said assist power; and antiskid hydraulic control valves connected to said first hydraulic connection to control said assist power to achieve desired antiskid control.

Claim 3

A system according to claim 1, wherein said master cylinder includes a master cylinder piston disposed coaxial of a first longitudinal axis of said master cylinder; said control valve includes a driver actuated member Disposed coaxial of said first axis and slidably disposed within said master cylinder piston, said member being driver actuated at one end thereof to connect said source to an activating surface of said master cylinder piston adjacent said one end of said driver actuated member; said activating cylinder including an actuating piston disposed in a slidably sealed relation within said activating cylinder coaxial of a second longitudinal axis of said activating cylinder to divide said actuating piston into a first chamber adjacent said other end of said activating cylinder and a second chamber adjacent said one end of said activating cylinder; said first hydraulic connection is connected between said activating surface and said first chamber; and said second hydraulic connection is connected between a third chamber in said master cylinder adjacent the end of said master cylinder piston remote from said activating surface and said second chamber; and further including a pressure actuated valve disposed in said activating cylinder to block said second hydraulic connection when said assist power is present.

Claim 4

A brake system according to claim 2, wherein said pressure activated valve is controlled by said assist power.

Claim 5

A brake system according to claim 3, wherein said antiskid valves are controlled by an antiskid control system, said antiskid valves having three different switching combinations.

Claim 6

A brake system according to claim 4, further including a reservoir for pressure medium employed in providing said assist power; and wherein said antiskid valves have a first switching combination to connect said first chamber to said actuating surface, a second switching combination to disconnect said first chamber from said actuating surface, and a third switching combination to connect said first chamber to said reservoir.

Claim 7

A brake system according to claim 5, wherein said second chamber of said activating cylinder is common to said wheel brake cylinder of each wheel of an axle.

Claim 8

A brake system according to claim 6, wherein said actuating piston includes a recess in the surface thereof adjacent said second chamber, a ring-shaped space between the inner wall of said actuating cylinder and the outer wall of said actuating piston, a plurality of bores interconnecting said recess and said space, and a valve disposed in said recess to block said plurality of bores when said assist power is present; and said second hyraulic connection is connected to said space.

Claim 9

A brake system according to claim 7, wherein one of said plurality of bores is coaxial of said second axis, and said valve includes a valve body disposed coaxial of said second axis within said recess, and a valve seat disposed in the adjacent port of said one of said plurality of bores.

Claim 10

A brake system according to claim 8, wherein said valve further includes a stem disposed coaxially of said second axis having one end fixed to said one end of said actuating cylinder, a hollow cylinder secured to the other end of said stem and extending into said recess, and an expanding spring disposed in said hollow cylinder, said valve body being disposed on the end of said hollow cylinder extending into said recess.

Claim 11

A brake system according to claim 5, wherein there is provided one of said actuating cylinder for each wheel of an axle and both of said actuating cylinders are connected to said first hydraulic connection.

Claim 12

A brake system according to claim 10, wherein said actuating piston of each of said actuating cylinders are maintained in its rest position aginast a stop in said first chamber by means of a spring in said second chamber supported by a collar.

Claim 13

A brake system according to claim 11, wherein said second chamber of each of said actuating cylinder includes a transverse bore through the wall of said actuating cylinder, and further including a common Transverse cylinder connected to said first hydraulic connection; a pair of T-shaped pistons each slidably sealed in said common cylinder and extending in opposite directions into said second chamber of a different one of said actuating cylinders in a slidably sealed relation through the associated one of said transverse bores, each of said T-shaped pistons moving in opposite directions and terminating within said second chamber in a different one of said actuating cylinder in a member that will block said second hydraulic connection.