Hydraulic brake control apparatus for a trailer hauled by a motor car

Claim 2

Hydraulic brake control apparatus for a trailer hauled by a motorcar, comprising driver-operated mechanical brake means for braking said motorcar and including a brake pedal means; a fluidic pressure generator on said motorcar located in, and operated by said brake pedal means for producing a flow of pressure fluid whose pressure depends on the force applied to said pedal means of driver-operated brake means; pressure responsive hydraulic trailer brake means for braking the trailer; and pressure conduit means connecting said pressure generator with said trailer brake means so that actuation of said pedal means of driver-operated brake means causes actuation of said trailer brake means and simultaneous braking of the motorcar and trailer.

Claim 3

Brake control apparatus as claimed in claim 1 wherein said driver-operated brake means include a brake on said motorcar, a brake lever, a bolt fixedly secured to said brake lever and having a piston portion formed with a valve seat, to said brake pedal means having a cylinder portion in which said piston portion is located so that a pressure chamber is formed in said cylinder portion and said pedal means can move relative to said bolt whereby the volume of said pressure chamber is reduced when said pedal means is depressed, a return spring in said pressure chamber abutting said bolt and said pedal means for returning said pedal to a normal inoperative position, said pedal means having a bore opposite said valve seat, a valve spring located in said bore, a needle valve member movably located in said bore and biassed by said valve spring toward said valve seat, said pedal means forming a reservoir for an operating fluid communicating through said valve seat with said pressure chamber in said normal inoperative position of said pedal means, said needle valve member closing said pressure chamber in the depressed position of said pedal means so that the pressure is increased in said chamber and pressure fluid flows through said pressure conduit means to said trailer brake means for operating the same together with said brake on said motorcar.

Claim 4

Hydraulic brake control apparatus for a trailer hauled by a motorcar, comprising driver-operated brake means for braking said motorcar, and including a brake on said motorcar, a brake lever, a bolt carried by said brake lever, and a driver-operated pedal means mounted on said bolt for limited movement, and forming with said bolt a pressure chamber of variable volume; a fluidic pressure generator on said motorcar including said chamber and actuated by said pedal means for producing a flow of pressure fluid whose force depends on the force applied to said pedal means; pressure responsive hydraulic trailer brake means for braking the trailer; and pressure conduit means connecting said pressure chamber with said trailer brake means so that upon actuation of said pedal means, said brake is operated and pressure fluid flows from said pressure chamber through said pressure conduit means to said trailer brake means and actuates said trailer brake means for simultaneous braking of the motorcar and of the trailer.

Claim 5

Hydraulic brake control apparatus for a trailer hauled by a motorcar, comprising driver-operated brake means for braking said motorcar, and including a brake on said motorcar, a brake lever, a bolt carried by said brake lever, and a driver-operated pedal means mounted on said bolt for limited movement, and forming with said bolt a pressure chamber of variable volume; a fluidic pressure generator on said motorcar including said chamber and actuated by said pedal means for producing a flow of pressure fluid whose force depends on the force applied to said pedal means; pressure responsive hydraulic trailer brake means for braking the trailer; and pressure conduit means connecting said pressure chamber with said trailer brake means so that upon actuation of said pedal means, said brake is operated and pressure fluid flows from said pressure chamber through said pressure conduit means to said trailer brake means and actuates said trailer brake means for simultaneous braking of the motorcar and of the trailer.

Claim 6

Brake control apparatus as claimed in claim 3 wherein said driver-operated brake means include a return spring located in said pressure chamber and having one end abutting said bolt and an other end abutting said pedal means and biassing said pedal means toward a normal inoperative position, and stop means limiting movement of said pedal means by said return spring relative to said bolt in said normal inoperative position.

Claim 7

Brake control apparatus as claimed in claim 3 wherein said pedal means includes two lateral walls and a step-on plate between said lateral walls, said lateral walls being located on opposite sides of said brake lever and slidably engaging the same so that said pedal means can not turn about said bolt.

Claim 8

Brake control apparatus as claimed in clAim 5 wherein said pressure conduit means is connected with said pressure chamber, detachably mounted on said pedal means, and partly located between said lateral walls.

Claim 9

Brake control apparatus as claimed in claim 3 wherein said pedal means includes a casing forming a reservoir for operating fluid communicating with said pressure chamber, and a control valve connecting said reservoir with said pressure chamber in a normal inoperative position of said pedal means, and closing said pressure chamber when said pedal means is depressed for reducing the volume of said pressure chamber.

Claim 10

Brake control apparatus as claimed in claim 7 wherein said casing has a top portion with a threaded bore, and includes a threaded plug having an air filter and being threaded into said threaded bore.

Claim 11

Brake control apparatus as claimed in claim 7 wherein said control valve including a valve seat formed in said bolt, and a spring biassed valve member movably mounted in said pedal means and operated by said pedal means to engage said valve seat when said pedal means is depressed.

Claim 12

Brake control apparatus as claimed in claim 3, further comprising second driver-operated brake means including second pedal means, a second brake lever secured to said second pedal means, and a second brake for braking said motorcar, and interconnecting means having a first position connecting said two brake pedal means for movement together so that the first pedal means reduces the volume of said pressure chamber when depressed together with said second pedal means so that both said brakes of said motorcar and said trailer brake means are together actuated, and a second position separating said two pedal means for independent movement so that said brakes of said motorcar can be selectively operated, and also blocking said first pedal means against movement relative to said brake lever and to said bolt so that the volume of said pressure chamber remains constant and said trailer brake means are not actuated when said first brake pedal means is depressed for actuating the first brake on said motorcar.

Claim 13

Brake control apparatus as claimed in claim 10 wherein said interconnecting means include a locking means mounted on the first brake lever which carries said bolt, for turning movement between a first position engaging a coupling slot in said second pedal means, and a second position releasing said coupling slot and located between said first brake lever which carries said bolt and the respective first pedal means so that the latter can not move relative to said bolt and to the respective brake lever.

Claim 14

Brake control apparatus as claimed in claim 10 wherein said first and second pedal means have first and second step-on surfaces, respectively, said first surface projecting from said second surface so as to be first engaged by the foot of the operator.

Claim 15

Brake control apparatus as claimed in claim 12 wherein said first surface is larger than said second surface.