Hydraulic power brake booster actuated trailer brake system

Claim 2

A hydraulic brake system for a towing vehicle and a trailer hitched thereto, which comprises: a hydraulic power boost device mounted To the towing vehicle and adapted to be connected to a hydraulic pressure source and to the vehicle brakes; said device having a pressure chamber and control means including valve means for regulating hydraulic pressure to said chamber for braking said vehicle; a hydraulic slave actuator having a piston slidably positioned therein; a hydraulic connection from the actuator to said pressure chamber for communicating chamber pressure to said actuator to drive said piston; and a master cylinder for the trailer brakes including a piston drivably connected to said actuator piston; said actuator being pivotally carried to the vehicle at the hitch point between the towing vehicle and the trailer so that misalignment therebetween in a horizontal plane can occur in turning; said master cylinder including a push rod detachably secured between said master cylinder piston and said actuator piston so that said vehicle and trailer may be separated.

Claim 3

A hydraulic brake system, as recited in claim 1, wherein said control means includes a foot pedal and lever means operatively connected to said valve means.

Claim 4

A hydraulic brake system, as recited in claim 1, in which said actuator and said trailer master cylinder are adapted to be mounted respectively, to the vehicle and to the trailer; said hydraulic connection comprising a flexible hose.

Claim 5

In a hydraulic brake system for a trailer adapted to be hitched to a towing vehicle, which vehicle includes a hydraulic brake system of its own having therein a pedal-operated hydraulic power brake booster operatively connected hydraulically to both of said systems to control their respective brakes, the improvement which comprises: a hydraulic slave actuator in the trailer brake system connected in hydraulic communication with said booster; and a master cylinder in said trailer brake system having a force transmitting member connected to said slave actuator; said actuator including a housing and a piston slidable therein; said actuator piston and said housing together forming a chamber in said housing with which said booster is hydraulically connected so that the pressure acting in said booster in response to pedal movement to apply the vehicle brakes also acts to apply the trailer brakes concurrently; a bearing support member pivotally mounting said actuator housing to said vehicle along the axis of the hitch connecting the vehicle and trailer.

Claim 6

In a hydraulic brake system for a trailer adapted to be hitched to a towing vehicle, which vehicle includes a hydraulic brake system of its own having therein a pedal-operated hydraulic power brake booster operatively connected hydraulically to both of said systems to control their respective brakes, the improvement which comprises: a hydraulic slave actuator in the trailer brake system connected in hydraulic communication with said booster; and a master cylinder in said trailer brake system having a force transmitting member connected to said slave actuator; said actuator including a housing and a piston slidable therein; said actuator piston and said housing together forming a chamber in said housing with which said booster is hydraulically connected so that the pressure acting in said booster in response to pedal movement to apply the vehicle brakes also acts to apply the trailer brakes concurrently; a bearing support member pivotally mounting said actuator housing to said vehicle along the axis of the hitch connecting the vehicle and trailer.

Claim 7

The improvement in claim 4, wherein said trailer master cylinder is mounted to said trailer; said force transmitting member connecting said actuator to said trailer master cylinder includes a swivel joint which permits vertical misalignment between vehicle and trailer.

Claim 8

The improvement in claim 5 wherein said swivel joint is separable so as to permit disconnecting the vehicle and trailer at said hitch.

Claim 9

In a hydraulic brake system for a towing vehicle and a towed vehicle hitched thereto, said towed vehicle having hydraulically actuated brakes: means for effecting a brake application, said means including a housing defining a pressure chamber therewithin, valve means for controlling fluid communication into said pressure chamber, and means operated by the vehicle operator to actuate said valve means to communicate fluid pressure into said pressure chamber when a brake application is effected; a first hydraulic actuator mounted on said towing vehicle, said first actuator including a housing defining a bore therewithin, and a piston slidably mounted in said bore and cooperating with one end of the latter to define a fluid compartment therebetween; means communicating said compartment with said pressure chamber, whereby said compartment is pressurized whenever fluid pressure is developed is said pressure chamber; a second hydraulic actuator mounted on said towed vehicle, said second actuator including a housing defining a bore therewithin and a piston slidable in said bore and cooperating with one end of the latter to Define a fluid cavity therebetween; means communicating said cavity with the hydraulic actuators on the brakes of the towed vehicle, whereby a trailer brake actuator is effectd when the fluid content of said cavity is pressureized; and mechanical linkage means interconnecting the piston in the first actuator with the piston in the second actuator.

Claim 10

In a hydraulic brake system for a towing vehicle and a towed vehicle hitched thereto, said towed vehicle having hydraulically actuated brakes: means for effecting a brake application, said means including a housing defining a pressure chamber therewithin, valve means for controlling fluid communication into said pressure chamber, and means operated by the vehicle operator to actuate said valve means to communicate fluid pressure into said pressure chamber when a brake application is effected; a first hydraulic actuator mounted on said towing vehicle, said first actuator including a housing defining a bore therewithin, and a piston slidably mounted in said bore and cooperating with one end of the latter to define a fluid compartment therebetween; means communicating said compartment with said pressure chamber, whereby said compartment is pressurized whenever fluid pressure is developed is said pressure chamber; a second hydraulic actuator mounted on said towed vehicle, said second actuator including a housing defining a bore therewithin and a piston slidable in said bore and cooperating with one end of the latter to Define a fluid cavity therebetween; means communicating said cavity with the hydraulic actuators on the brakes of the towed vehicle, whereby a trailer brake actuator is effectd when the fluid content of said cavity is pressureized; and mechanical linkage means interconnecting the piston in the first actuator with the piston in the second actuator.

Claim 11

The invention of claim 7; and means pivotally mounting one of said actuators to the corresponding vehicle to permit actuation the one theOactuator with respect to said corresponding vehicle about a generally vertical axis.

Claim 12

The invention of claim 7: said mechanical linkage means including a push rod; means retaining one end of said push rod to the piston in said first actuator; and means retaining the opposite end of said push rod to the piston in said second actuator.