Electrically actuated trailer brake control system

Claim 2

A means for controlling brake pressure of a towed vehicle as a function of brake pressure of a towing vehicle, said controlling means comprising: a first means for monitoring brake pressure in said towing vehicle; a second means for monitoring brake pressure in said towed vehicle; means for compariNg outputs from said first monitoring means and said second monitoring means, said comparing means having an output proportional to any difference between the brake pressures of said towing vehicle and said towed vehicle; power means for applying the brakes of said towed vehicle when the brakes of said towing vehicle have been applied; and means for varying said power means as a function of said proportional output of said comparing means, said varying means keeping brake pressure in said towed vehicle proportional to brake pressure in said towing vehicle, said varying means comprising a switching means for operating a valving means from said proportional output, said valving means reducing force from said power means to the brakes of said towed vehicle, said valving means providing a fast reduction in force from said power means, said power means comprising a means for slowly reducing the force from said power means to the brakes of said towed vehicle.

Claim 3

In a brake actuation system for actuating the brakes of a trailer in response to a brake actuation of the towing vehicle: means for generating a first signal proportional to the braking pressure generated by the towing vehicle; means for generating a second signal proportional to the braking pressure generated in the trailer; means for comparing said first and second signals and generating a third signal when the first signal exceeds the second signal by a predetermined amount, means for generating a fourth signal when the brakes of the towing vehicle are actuated, means for generating braking pressure in said trailer including a housing, a diaphragm in said housing, means responsive to movement of said diaphragm for generating said trailer braking pressure, said diaphragm defining a pair of chambers between opposite sides of the diaphragm and corresponding ends of said housing, means normally communicating each of said chambers to a common pressure source, means responsive to said fourth signal for terminating communication between one of said chambers and said common pressure source, and means responsive to said third signal for initiating communication between said one chamber and another pressure source greater than the common pressure source whereby said diaphragm means is moved to generate trailer braking pressure.

Claim 4

In a brake actuation system for actuating the brakes of a trailer in response to a brake actuation of the towing vehicle: means for generating a first signal proportional to the braking pressure generated by the towing vehicle; means for generating a second signal proportional to the braking pressure generated in the trailer; means for comparing said first and second signals and generating a third signal when the first signal exceeds the second signal by a predetermined amount, means for generating a fourth signal when the brakes of the towing vehicle are actuated, means for generating braking pressure in said trailer including a housing, a diaphragm in said housing, means responsive to movement of said diaphragm for generating said trailer braking pressure, said diaphragm defining a pair of chambers between opposite sides of the diaphragm and corresponding ends of said housing, means normally communicating each of said chambers to a common pressure source, means responsive to said fourth signal for terminating communication between one of said chambers and said common pressure source, and means responsive to said third signal for initiating communication between said one chamber and another pressure source greater than the common pressure source whereby said diaphragm means is moved to generate trailer braking pressure.

Claim 5

The invention of claim 2, said common pressure source being the engine manifold vacuum of the towing vehicle, said another pressure source being atmospheric pressure.

Claim 6

The invention of claim 3, and a bleed orifice in said diaphragm to permit limited communication between said chambers, and resilient means yieldably urging said diaphragm means toward said one chamber, whereby said trailer braking pressure is gradually reduced during generation of said fourth signal when said third signal is not generated.

Claim 7

The invention of claim 3; and means within said braking pressure generator means to gradually reduce trailer braking pressure during generation of said fourth signal when said third signal is not generated.