Deceleration energized load controlled brake valve

Claim 2

A displacement type fluid pressure proportioner having an inlet and an outlet and comprising: a first displacement piston having opposed effective differential areas one of which is subjected to an inlet pressure and the other of which is selectively subjected to the inlet pressure and an outlet pressure, and first resiliently yieldable means urging said piston in an outlet pressure increasing direction, control means having a first control condition subjecting both of said opposed effective differential areas to an increasing inlet pressure whereby said first piston is moved against said first resiliently yieldable means and outlet pressure is the same as inlet pressure, and a second control condition disconnecting the other effective differential area from the inlet and subjecting it to the outlet pressure whereby the first mentioned first piston movement is stopped and further inlet pressure increase moves said first piston in the opposite direction to increase outlet pressure in a predetermined ratio with the increase in inlet pressure by displacement, second resiliently yieldable means and a second piston having an effective area subjected to the inlet pressure urging it to move in the first piston opposite direction against said second resiliently yieldable means and engageable with said first piston at a point which is a function of the increase in inlet pressure and the inlet pressure at which said control means changes from said first control condition to said second control condition, said second piston upon further increase in inlet pressure after engagement with said first piston exerting additional force on said first piston in said first piston opposite direction of movement.

Claim 3

The proportioner of claim 1 in which the inlet and outlet are adapted to be connected in a vehicle hydraulic braking circuit to proportion brake apply pressure to a hydraulically actuated brake to decelerate the vehicle, said control means comprising a vehicle deceleration rate sensing valve which moves from the open first control condition to the closed second control condition when a predetermined vehicle deceleration rate is attained, and returns to the first control condition when the vehicle deceleration rate falls below the predetermined vehicle deceleration rate.

Claim 4

The proportioner of claim 1 in which the inlet and outlet are adapted to be connected in a first vehicle hydraulic braking circuit providing brake supply pressure to the inlet to proportion brake apply pressure from the outlet to a hydraulically actuated brake to decelerate the vehicle, and means adapted to sense brake supply pressures in the first vehicle hydraulic braking circuit and a second vehicle hydraulic braking circuit and acting upon a predetermined pressure differential therebetween characterized by a relative decrease in the second vehicle hydraulic braking circuit brake supply pressure to fluid connect said inlet to said outlet through said first piston independently of said control means.

Claim 5

A brake apply pressure proportioner for a vehicle brake system circuit having a source of vehicle operator-controlled brake supply pressure, said proportioner comprising: a housing having an axially extending bore therein, a brake supply pressure inlet and a brake apply pressure outlet connected with said bore, said housing being axially oriented generally fore-and-aft of the vehicle when installed therein; a proportioner piston reciprocably received in one end of said bore adjacent said outlet and having a forwardly opening first recess in the forward end thereof and a rearwardly opening second recess in the rearward end thereof; first and second passage means connecting said first and second recesses; first valve means normally closing said first passage means connection to said first recess; said piston having a flange between said ends of greater diameter than either of said ends and sealingly fitting said bore one end with said piston rearward end forming with said bore one end an annular chamber communicating with said outlet; means on said piston rearward end closing said second recess; third passage means operatively fluid connecting said first passage means and said annular chamber; a multiplier piston reciprocably received in the other end of said bore adjacent said inlet and having a stepped bore therethrough, said proportioner piston forward end being reciprocably and sealingly received in the larger portion of said stepped bore, said inlet being in fluid communication with said other bore end and with said stepped bore to provide brake supply pressure therein and in said proportioner piston first recess; first spring means yieldably resisting forward movement of said proportioner piston and second spring means yieldably resisting rearward movement of said multiplier piston; deceleration rate sensing valve means sensitive to a predetermined vehicle deceleration rate to close said first passage means connection to said second recess and thereby fluidly disconnect brake supply pressure and brake apply pressure; said brake supply pressure acting with said first spring means on said proportioner piston in opposition to brake apply pressure acting thereon to displace said proportioner piston toward said outlet and increase brake apply pressure at a first proportionate rate from the pressure at the time said deceleration rate sensing valve means closed said connection to a higher brake apply pressure determined by the amount of displacement of said proportioner piston available as established by the amount of prior forwarD movement thereof under influence of brake pressure before said deceleration rate sensing valve means closed; and means actuable under a predetermined vehicle brake system condition to move said first valve means to open the connection of said first passage means to said first recess and establish brake supply pressure communication therethrough to said outlet independently of vehicle deceleration.

Claim 6

A brake apply pressure proportioner for a vehicle brake system circuit having a source of vehicle operator-controlled brake supply pressure, said proportioner comprising: a housing having an axially extending bore therein, a brake supply pressure inlet and a brake apply pressure outlet connected with said bore, said housing being axially oriented generally fore-and-aft of the vehicle when installed therein; a proportioner piston reciprocably received in one end of said bore adjacent said outlet and having a forwardly opening first recess in the forward end thereof and a rearwardly opening second recess in the rearward end thereof; first and second passage means connecting said first and second recesses; first valve means normally closing said first passage means connection to said first recess; said piston having a flange between said ends of greater diameter than either of said ends and sealingly fitting said bore one end with said piston rearward end forming with said bore one end an annular chamber communicating with said outlet; means on said piston rearward end closing said second recess; third passage means operatively fluid connecting said first passage means and said annular chamber; a multiplier piston reciprocably received in the other end of said bore adjacent said inlet and having a stepped bore therethrough, said proportioner piston forward end being reciprocably and sealingly received in the larger portion of said stepped bore, said inlet being in fluid communication with said other bore end and with said stepped bore to provide brake supply pressure therein and in said proportioner piston first recess; first spring means yieldably resisting forward movement of said proportioner piston and second spring means yieldably resisting rearward movement of said multiplier piston; deceleration rate sensing valve means sensitive to a predetermined vehicle deceleration rate to close said first passage means connection to said second recess and thereby fluidly disconnect brake supply pressure and brake apply pressure; said brake supply pressure acting with said first spring means on said proportioner piston in opposition to brake apply pressure acting thereon to displace said proportioner piston toward said outlet and increase brake apply pressure at a first proportionate rate from the pressure at the time said deceleration rate sensing valve means closed said connection to a higher brake apply pressure determined by the amount of displacement of said proportioner piston available as established by the amount of prior forwarD movement thereof under influence of brake pressure before said deceleration rate sensing valve means closed; and means actuable under a predetermined vehicle brake system condition to move said first valve means to open the connection of said first passage means to said first recess and establish brake supply pressure communication therethrough to said outlet independently of vehicle deceleration.