Control valve system

Claim 2

In a dual hydraulic brake system having a separate hydraulic pressure supply for each system and each system having at least one pressure responsive brake, means operable generally for modulating the pressure of one of said systems to vary the pressure to the brake thereof, an electrical circuit for energization to warn the vehicle operator of a failure in said one system and the other of said systems, and a device for bypassing said modulating means and energizing said circuit, said device comprising a by-pass means subjected to the pressures of said systems for controlling said circuit, said other means being movable from a normally centered position toward opposed translated positions in response to the pressures in one of said one and other systems upon the failure of the other of said one and other systems to effect the energization of said circuit, and said other means including means for controlling said by-pass passage, said included means being movable with said other means toward at least one of its translated positions to establish flow through said by-pass passage to said one system.

Claim 3

In a dual fluid pressure brake system having a separate fluid pressure supply for each system and each system including at least one brake, a proportioning valve for one of said systems operable generally for reducing the fluid pressure to the brake of said one system, an electrical circuit for energization to warn the vehicle operator of a failure in said one system and the other of said systems, and a device for by-passing said proportioning valve and energizing said circuit, said device comprising movable means subjected to the fluid pressures of said systems for comparing the magnitudes thereof, a by-pass passage in said device and connected in said one system in by-pass relation with said proportioning valve, and said movable means including means for controlling said by-pass passage, and other means for selectively energizing said circuit under preselected conditions, said other means being movable upon movement of said movable means from a normally centered position toward opposed translated positions to selectively energize said circuit in response to the fluid pressure in one of said one and other systems upon the failure of the other of said one and other systems and said included means being movable with said movable means toward at least one of its translated positions to establish pressure fluid flow through said by-pass passage to the brake of said one system.

Claim 4

In a dual fluid pressure brake system having a separate fluid pressure supply for each system and each system including at least one brake, a proportioning valve for one of said systems operable generally for reducing the fluid pressure to the brake of said one system, an electrical circuit for energization to warn the vehicle operator of a failure in said one system and the other of said systems, and a device for by-passing said proportioning valve and energizing said circuit, said device comprising movable means subjected to the fluid pressures of said systems for comparing the magnitudes thereof, a by-pass passage in said device and connected in said one system in by-pass relation with said proportioning valve, and said movable means including means for controlling said by-pass passage, and other means for selectively energizing said circuit under preselected conditions, said other means being movable upon movement of said movable means from a normally centered position toward opposed translated positions to selectively energize said circuit in response to the fluid pressure in one of said one and other systems upon the failure of the other of said one and other systems and said included means being movable with said movable means toward at least one of its translated positions to establish pressure fluid flow through said by-pass passage to the brake of said one system.

Claim 5

In a dual fluid pressure system according to claim 2, comprising signal means connected in said circuit for warning the vehicle operator upon the failure of said one and other systems, and said device including switch means for engagement with said other means and connected in said circuit to normally interrupt energization thereof when said movable means is in its centered position, said switch means completing said circuit and to energize said signal means upon the movement of said movable means to its translated positions.

Claim 6

In a dual fluid pressure brake system according to claim 2, wherein said movable means includes piston means having opposed portions subjected to the fluid pressures in said systems, and said included means being operatively associated with one of said opposed portions and defining valve means for controlling said by-pass passage, said valve means being movable toward a position providing the pressure fluid flow through said by-pass passage upon the movement of said piston means to its one position, and said other means being on said piston means between said opposed portions.

Claim 7

In a dual fluid pressure brake system according to claim 4, wherein said valve means includes a sealing member engaged with said by-pass passage to interrupt pressure fluid flow therethrough when said piston means is in its centered position and movable to a position disengaged from said by-pass passage and establishing the pressure fluid flow therethrough upon the movement of said piston means to its one translated position.

Claim 8

In a dual fluid pressure brake system having a pair of system branches and each branch including at least one brake, a separate fluid pressure supply for each branch, a proportioning valve for one of said branches operable generally for reducing the fluid pressure to the brake of said one branch, an electrical circuit for energization to warn the vehicle operator of a failure in said one branch or the other of said branches, and a device for by-passing said proportioning valve and energizing said circuit, said device comprising a housing having a pair of chambers therein and connected with said branches, respectively, by-pass passage means in said housing connecting one of said chambers in by-pass relation with said proportioning valve in said one branch, piston means movable between said chambers from a normally centered position toward opposed translated positions in response to the fluid pressure of one of said one and other branches upon the failure of the fluid pressure in the other of said one and other branches, switch means in said housing and connected in said circuit for controlling energization thereof, means on said piston means for engagement with said switch means to energize said circuit upon the movement of said piston means to its translated positions, and said piston means including valve means for controlling said by-pass passage, said valve means being movable toward a position providing pressure fluid flow through said by-pass passage upon the movement of said piston means to one of its translated positions.

Claim 9

In a dual fluid pressure brake system having a pair of system branches and each branch including at least one brake, a separate fluid pressure supply for each branch, a proportioning valve for one of said branches operable generally for reducing the fluid pressure to the brake of said one branch, an electrical circuit for energization to warn the vehicle operator of a failure in said one branch or the other of said branches, and a device for by-passing said proportioning valve and energizing said circuit, said device comprising a housing having a pair of chambers therein and connected with said branches, respectively, by-pass passage means in said housing connecting one of said chambers in by-pass relation with said proportioning valve in said one branch, piston means movable between said chambers from a normally centered position toward opposed translated positions in response to the fluid pressure of one of said one and other branches upon the failure of the fluid pressure in the other of said one and other branches, switch means in said housing and connected in said circuit for controlling energization thereof, means on said piston means for engagement with said switch means to energize said circuit upon the movement of said piston means to its translated positions, and said piston means including valve means for controlling said by-pass passage, said valve means being movable toward a position providing pressure fluid flow through said by-pass passage upon the movement of said piston means to one of its translated positions.

Claim 10

In a dual hydraulic brake system having at least one pressure responsive brake in each system, a dual master cylinder having separate pressure supplies in each system and operable generally to transmit pressure in each system to actuate the brakes thereof, proportioning means in one of said systems operable generally in response to pressure supplied thereto from one of said master cylinder supplies to vary the pressure applied to the brake of said one system under preselected conditions, an electrical driver warning circuit for energization to warn the vehicle driver upon the failure of the respective pressures in said one system and the other of said systems, and a device connected in each system and in said circuit for by-passing said proportioning means and energizing said circuit under preselected conditions, said device comprising a by-pass passage connected in said one system in by-pass relation with said proportioning means between said one master cylinder supply and the brake of said one system, and movable means for controlling said by-pass passage and said circuit, said movable means being movable from a normal position toward opposed translated positions in response to the failure of fluid pressure in one of said one and other systems to effect the energization of said circuit and in one of the translated positions opening said by-pass passage to establish flow therethrough.

Claim 11

In a dual hydraulic brake system having at least one pressure responsive brake in each system, a dual master cylinder having separate pressure supplies in each system and operable generally to transmit pressure in each system to actuate the brakes thereof, proportioning means in one of said systems operable generally in response to pressure supplied thereto from one of said master cylinder supplies to vary the pressure applied to the brake of said one system under preselected conditions, an electrical driver warning circuit for energization to warn the vehicle driver upon the failure of the respective pressures in said one system and the other of said systems, and a device connected in each system and in said circuit for by-passing said proportioning means and energizing said circuit under preselected conditions, said device comprising a by-pass passage connected in said one system in by-pass relation with said proportioning means between said one master cylinder supply and the brake of said one system, and movable means for controlling said by-pass passage and said circuit, said movable means being movable from a normal position toward opposed translated positions in response to the failure of fluid pressure in one of said one and other systems to effect the energization of said circuit and in one of the translated positions opening said by-pass passage to establish flow therethrough.

Claim 12

A vehicle hydraulic split brake system comprising a dual master cylinder having separate pressurizing chambers respectively generating pressures in a first brake pressurizing circuit for energizing a first group of vehicle wheel brake actuators and in a second brake pressurizing circuit for energizing a second group of vehicle wheel brake actuators, a pressure regulator in said first circuit for reducing brake pressure delivered to said first group of vehicle wheel brake actuators from said master cylinder, a brake pressure control sensing brake pressure in said first circuit fluidly intermediate saiD master cylinder and said regulator and sensing brake pressure in said second circuit and including a pressure regulator bypass piston having a first position connecting said first circuit to said first group of vehicle wheel brake actuators through said regulator, said brake pressure control being responsive to a predetermined sensed brake pressure differential between said sensed brake pressures caused by a pressure loss in said second circuit to place said bypass piston in a second position to bypass said pressure regulator and directly fluid connect said first vehicle wheel brake actuators and said dual master cylinder to deliver full brake pressure through said first circuit without pressure reduction, said brake pressure control having a housing provided with a bore, said bypass piston being reciprocably movable in said bore in response to said sensed pressurized differential, said bypass piston having an annular space connected to said pressure regulator and to said first group of vehicle wheel brake actuators when said bypass piston is in said first position, said annular space being disconnected from said pressure regulator, and said first group of vehicle wheel brake actuators being fluid connected through a working chamber defined by one end of said bypass piston and said housing to said first brake pressurizing circuit intermediate said master cylinder and said regulator when said bypass piston is in said second position, and further comprising a pressure failure indicating circuit having a circuit control actuated by movement of said bypass piston from said first to said second position.

Claim 13

A vehicle hydraulic split brake system comprising a dual master cylinder having separate pressurizing chambers respectively generating pressures in a first brake pressurizing circuit for energizing a first group of vehicle wheel brake actuators and in a second brake pressurizing circuit for energizing a second group of vehicle wheel brake actuators, a pressure regulator in said first circuit for reducing brake pressure delivered to said first group of vehicle wheel brake actuators from said master cylinder, a brake pressure control sensing brake pressure in said first circuit fluidly intermediate saiD master cylinder and said regulator and sensing brake pressure in said second circuit and including a pressure regulator bypass piston having a first position connecting said first circuit to said first group of vehicle wheel brake actuators through said regulator, said brake pressure control being responsive to a predetermined sensed brake pressure differential between said sensed brake pressures caused by a pressure loss in said second circuit to place said bypass piston in a second position to bypass said pressure regulator and directly fluid connect said first vehicle wheel brake actuators and said dual master cylinder to deliver full brake pressure through said first circuit without pressure reduction, said brake pressure control having a housing provided with a bore, said bypass piston being reciprocably movable in said bore in response to said sensed pressurized differential, said bypass piston having an annular space connected to said pressure regulator and to said first group of vehicle wheel brake actuators when said bypass piston is in said first position, said annular space being disconnected from said pressure regulator, and said first group of vehicle wheel brake actuators being fluid connected through a working chamber defined by one end of said bypass piston and said housing to said first brake pressurizing circuit intermediate said master cylinder and said regulator when said bypass piston is in said second position, and further comprising a pressure failure indicating circuit having a circuit control actuated by movement of said bypass piston from said first to said second position.

Claim 14

In a dual hydraulic system having first and second lines normally subject to substantially equal pressures, a sensing unit connected to said first and second lines to produce a signal responsive to a predetermined pressure differential between said lines, a pressure changing device in one of said lines and valve means operable by said sensing unit responsive to said pressure differential to change the connection of said pressure changing device in said one line, the improvement comprising said sensing unit including a housing, a first member movable in said housing responsive to said predetermined pressure differential and having a neutral position when said pressures are balanced, a second member in said housing, said first and second members being constructed and arranged to provide relative movement between said first and second members by said predetermined pressure differential, cooperating valve means carried by said first and second members and operable by movement of said first member to change the connection of said pressure changing device in said one line, and spring means operable in said neutral position to bias said cooperating valve means into sealing engagement, wherein said first member is axially movable, one of said members includes a passage and the other of said members carries a valve means operable to close said passage in one position of said first member, and to open said passage in another position of said first member and wherein said passage is adjacent said first member.

Claim 15

In a dual hydraulic system having first and second lines normally subject to substantially equal pressures, a sensing unit connected to said first and second lines to produce a signal responsive to a predetermined pressure differential between said lines, a pressure changing device in one of said lines and valve means operable by said sensing unit responsive to said pressure differential to change the connection of said pressure changing device in said one line, the improvement comprising said sensing unit including a housing, a first member movable in said housing responsive to said predetermined pressure differential and having a neutral position when said pressures are balanced, a second member in said housing, said first and second members being constructed and arranged to provide relative movement between said first and second members by said predetermined pressure differential, cooperating valve means carried by said first and second members and operable by movement of said first member to change the connection of said pressure changing device in said one line, and spring means operable in said neutral position to bias said cooperating valve means into sealing engagement, wherein said first member is axially movable, one of said members includes a passage and the other of said members carries a valve means operable to close said passage in one position of said first member, and to open said passage in another position of said first member and wherein said passage is adjacent said first member.