Title: -
HDRAULIC BRAKE VALVE FOR TROLLEY ATTACHMENT TO TRACTOR WITH POWER SAVING AND COMBINE OPERATION WITH AUXILLARY HYDRAULIC SYSTEM
Application: -
a) Tractor trolley and trailer.
b) Trailer of Truck.
c) Automotive platform with heavy load.
Claims : -
1. The device is operated by vehicle having pressurized fluid available (Hydraulic Pump) and Hydraulic brakes for main vehicle, with independent pressure setting for brake and combined operation for auxiliary equipment.
2. The device is operated by vehicle having pressurized fluid available (Hydraulic Pump) and Mechanical brakes for main vehicle, with independent pressure setting for brake and combined operation for auxiliary equipment.

Detail Description: -
a) The device is operated by vehicle having pressurized fluid available (Hydraulic Pump) and Hydraulic brakes for main vehicle, with independent pressure setting for brake and combined operation for auxiliary equipment

Description of Diagram: -
The oil from the oil sump is pumped by the HYD PUMP ( Hydraulic Pump) which is already connected to the engine in the tractor, then this line is connected to the BRAKE VALVE ( Shown in the square in the above diagram) In this BRAKE VALVE there are two Check valves and One BRAKE PR CONTROL ( Brake Pressure control) device. From this BRAKE VALVE one line is connected to TRAILER BRAKE CYLINDER through quick release coupling (SIDE A & SIDE B in drawing) between brake valve and brake cylinder and other line is connected to EXISTING HYDRAULIC SYSTEM OF TRACTOR. To this BRAKE VALVE a line from master brake cylinder of tractor connecting the brake cylinder of the tractor. In “NO TRAILER” condition the port used to connect the brake line is connected to additional port with quick release coupling (SIDE B1)

Operating logic: -
The oil (Hydraulic Oil) which is pumped by the HYD PUMP connected to the tractor normally flows from the BRAKE VALVE and enters into the EXISTING HYDRAULIC SYSTEM OF TRACTOR. Whenever the auxiliary operation is to be done by the tractor the pressure from the line is prevented to enter the brake cylinder because of the check valve provided after the BRAKE PRESSURE CONTROL VALVE.
When the Brakes are applied by used of Master cylinder on the tractor the same oil (Brake oil) is used as a Pilot to actuate the BRAKE VALVE and the Hydraulic oil enters the TRAILER BRAKE CYLINDER and pressurizes the same the max pressure can be set using the BRAKE PRESSURE CONTROL VALVE (Say Set pressure is P1) . As soon as the pressure increases the pressure P1 the oil is by‐passed and returns in the hydraulic system of the tractor and thus the other operation is also possible at the same time. if the Load on the hydraulic system of the tractor exceeds P1 then depending upon the load the P1 also varies up to the pressure setting of tractor hydraulics and thus when the load reduced below P1 the brake pressure does not come below P1.
Also the positioning of the valve defines the priority for BRAKE VALVE and then the hydraulic system of the tractor. The BRAKE VALVE is operated in proportional with the master brake cylinder of tractor. So the force applied on the brakes changes with respect to drivers force on the BRAKE pedal. Whenever the force on brake pedal is removed the BRAKE VALVE also becomes neutral by spring action, and allows the tractor to operate normally.
Hence this valve has a feature to operate the both BRAKES and other hydraulic operation at the same time. Hence this is a valve for COMBINED OPERATION
In “NO TRAILER” condition the when SIDE A for broke cylinder is connected to SIDE B1, during operation of valve the oil which enters the brake line bypasses the oil directly to auxiliary hydraulic system of tractor. This saves power of tractor when no trailer is attached and brakes of tractor is applied. Please refer below diagram.

b) The device is operated by vehicle having pressurized fluid available (Hydraulic Pump) and Mechanical brakes for main vehicle, with independent pressure setting for brake and combined operation for auxiliary equipment.

Description of Diagram: -
The oil from the oil sump is pumped by the HYD PUMP ( Hydraulic Pump) which is already connected to the engine in the tractor, then this line is connected to the BRAKE VALVE ( Shown in the square in the above diagram) In this BRAKE VALVE there are two Check valves and One BRAKE PR CONTROL ( Brake Pressure control) device. From this BRAKE VALVE one line is connected to TRAILER BRAKE CYLINDER and other line is connected to EXISTING HYDRAULIC SYSTEM OF TRACTOR. To operate this BRAKE VALVE a cable is connected between the valve and brake pedal of the tractor, which acts as a mechanical link. In “NO TRAILER” condition the port used to connect the brake line is connected to additional port with quick release coupling (SIDE B1)

Operating logic: -
The oil (Hydraulic Oil) which is pumped by the HYD PUMP connected to the tractor normally flows from the BRAKE VALVE and enters into the EXISTING HYDRAULIC SYSTEM OF TRACTOR. Whenever the auxiliary operation is to be done by the tractor the pressure from the line is prevented to enter the brake cylinder because of the check valve provided after the BRAKE PRESSURE CONTROL VALVE.
When the Brakes are applied of tractor using the brake pedal the cable connected to the BRAKE valve, actuate the BRAKE VALVE and the Hydraulic oil enters the TRAILER BRAKE CYLINDER and pressurizes the same the max pressure can be set using the BRAKE PRESSURE CONTROL VALVE (Say Set pressure is P1) . As soon as the pressure increases the pressure P1 the oil is by‐passed and returns in the hydraulic system of the tractor and thus the other operation is also possible at the same time. if the Load on the hydraulic system of the tractor exceeds P1 then depending upon the load the P1 also varies up to the pressure setting of tractor hydraulics and thus when the load reduced below P1 the brake pressure does not come below P1.
Also the positioning of the valve defines the priority for BRAKE VALVE and then the hydraulic system of the tractor. The BRAKE VALVE is operated in proportional with the distance of travel of brake pedal of tractor. So the force applied on the brakes changes with respect to drivers force on the BRAKE pedal. Whenever the force on brake pedal is removed the BRAKE VALVE also becomes neutral by spring action, and allows the tractor to operate normally.
Hence this valve has a feature to operate the both BRAKES and other hydraulic operation at the same time. Hence this is a valve for COMBINED OPERATION
In “NO TRAILER” condition the when SIDE A for broke cylinder is connected to SIDE B1, during operation of valve the oil which enters the brake line bypasses the oil directly to auxiliary hydraulic system of tractor. This saves power of tractor when no trailer is attached and brakes of tractor is applied. Please refer below diagram.