Description:TRAILER CONTROL VALVE FOR AIR BRAKE SYSTEM AND METHOD THEREOF
FIELF OF THE INVENTION
The present invention relates to a control valve for air brake system. More particularly, the present invention relates to a trailer control valve for air brake system for combination vehicle, such as a truck and trailer which controls and regulates the air pressure supplied to the trailer brakes. Advantageously, the present invention achieves better control and stability when maneuvering the entire combination vehicle, and maintains proper air pressure and ensures effective braking performance.
BACKGROUND OF THE INVENTION
A braking system is a crucial component in vehicles that is designed to slow down or bring the vehicle to a complete stop. It is a safety feature that allows drivers to control their speed and maneuver their vehicles effectively.
The development of efficient braking systems has been instrumental in ensuring the safety and reliability of vehicles, especially in the realm of transportation. Among these systems, the air brake system stands out as a crucial component in commercial vehicles, such as trucks, buses, and trains. The air brake system's design and functionality play a pivotal role in enhancing braking efficiency, ensuring driver control, and contributing to overall road safety.
Air brake systems operate on the principle of compressed air to control and apply the brakes. These systems are widely used in heavy-duty vehicles due to their superior performance and reliability. The key components of an air brake system include an air compressor, air storage tanks, brake chambers, and various control valves. The system's functionality involves the generation of compressed air, its storage, and controlled release to actuate the braking mechanism.

In an air brake system, the trailer control valve serves as a central component in the air brake system of heavy vehicles, particularly those with trailers. Its primary function is to control the flow of compressed air between the tractor (front) and trailer (rear) braking systems. This control is vital for maintaining synchronization and balance during braking, ensuring that both the tractor and trailer decelerate uniformly.
Some of the prior arts are:
EP0883538B1 discloses a trailer control valve for a motor-vehicle compressed-air brake system comprising a control piston (90, 95) for actuating a double-seat valve (91) used to control the connection between a compressed-air supply, a compressed-air consumer and a pressure release point. To simplify the structure of the trailer control valve (14), a control piston (90) is associated jointly with an electrical control circuit and a pneumatic control circuit of a service brake system. A valve connected to the pneumatic control circuit of the service brake system is also provided. Said valve blocks the pneumatic control circuit of the service brake system relative to the trailer control valve (14) when the electrical control circuit is in operation and releases the pneumatic control circuit of the service brake system when the electrical control circuit fails.
US6206481B1 discloses a trailer control valve for a compressed air brake system for motor vehicles comprises control pistons for actuating a double seat valve, which can control the communication between a compressed air reservoir, a compressed air consumer, and a pressure relief location. In order to structurally simplify the trailer control valve, a control piston is provided that is jointly associated with an electrical control circuit and a pneumatic control circuit of a service brake system. Furthermore, a valve is provided that is connected to the pneumatic control circuit of the service brake system, which closes the pneumatic control circuit of the service brake off from to the trailer control valve when the electrical control circuit is functional, and in the event of a failure of the electrical control circuit, unblocks the pneumatic control circuit of the service brake system.
EP0600178B1 discloses a for a two-line air brake system with a trailer supply line arranged between the tractor and the trailer and with a trailer brake line likewise arranged between the tractor and the trailer. The trailer control valve has a pressure-medium inlet chamber (59, 15), a pressure-medium outlet chamber (10) and a control chamber (2). The pressure-medium inlet chamber (59, 15) is connected via a first throttle (38, 37, 33, 35), which can be adjusted from an unthrottled operating position towards smaller cross-sections of passage, to a supply line of the tractor. Via the first throttle (38, 37, 33, 35), the trailer supply line is furthermore connected to the supply line (40) of the tractor. A control piston (41, 49) is provided for the operation of the first throttle (38, 37, 33, 35). This control piston can be subjected on both sides to pressure medium via respective control chambers (43, 60, 26), the second control chamber (43, 60) being connected via a connecting line (55, 57) to the control chamber (2) of the trailer control valve and its first control chamber (26) being connected to the pressure-medium inlet chamber (59, 15). If the trailer brake line fractures, the tractor supply line feeding the trailer control valve is throttled by means of the first throttle (38, 37, 33, 35).
However, the conventional trailer control valve as discussed in the prior art have relatively slower response time lead to affect the overall braking performance, especially in emergency situations, offers limited precision in controlling the braking force on individual wheels, and requires regular maintenance leads to higher costs for repairs and maintenance.
Accordingly, there is a need for an improved trailer control valve for air brake system which provides more precise control over the application and release of brakes which contributes to better overall braking performance, especially in varying road and load conditions, and enhances the overall control of the entire vehicle combination that allows the driver to have better control over the braking system, ensuring a safer and more predictable response during various driving conditions.

OBJECT OF THE INVENTION
The principal object of the present invention is to provide a trailer control valve for air brake system for combination vehicle.
Another object of this invention is to provide a trailer control valve which allows for proportional brake application between the tractor (or towing vehicle) and the trailer, and ensures that the brakes on both the tractor and trailer are applied smoothly and proportionally, helping to prevent sudden and uneven braking.
Another object of this invention is to contribute to better stability during braking by regulating the air pressure to the trailer brakes based on the tractor's brake application, particularly important in preventing skidding or jackknifing of the trailer.
Another object of the present invention is to extend and control dual line and dual circuit service braking system to trailer from the towing vehicle’s Dual brake valve.
Yet another object of the present invention is to extend and control parking brake system to trailer from the towing vehicle’s Hand brake valve.
Another object of the present invention is to provide emergency (autonomous) braking of trailer, in the event of trailer breakaway situation.
SUMMARY OF THE INVENTION
It is a primary aspect of the present invention to provide a trailer control valve (100) for air brake system, comprising: a. a valve body (101) provided with a supply port (11) receives compressed air from the vehicle's air compressor, delivery port (21 & 22) sends regulated air pressure to the trailer brakes, control port (41, 42 & 43) receives signals to control the valve operation, exhaust port allows the release of air pressure when needed; a primary piston (104); a spring loaded secondary piston arrangement (105); a spring; an inversion piston arrangement (108); a seal; an inversion piston (108) provided with inversion mechanism to change the direction of movement; a pilot operated 2/2valve (130), and a bonded valve (125) connected to one of the primary (104) or secondary pistons (116) and opens or closes based on the movement of that piston, and controls the flow of fluid to specific parts of the system.
The trailer control valve (100) connected to both towing vehicle air brake system and the trailer's air brake system works under four different conditions: (i) during trailer control valve (100) OFF state, both primary (104) and secondary piston (116) are held at top and inversion piston (108) is at balanced state by the pressure from parking control port (43) & supply pressure from supply port (11), such that the inlet valve of bonded valve (125) is closed by spring load (126) and therefore supply pressure not pass through valve to delivery (22), but the supply pressure flows to the supply delivery (21) for trailer supply line charging, (ii) during service brake ON state, (Foot brake valve depressed condition), when the driver applies the foot brake in the towing vehicle, the air pressure in the system increases which is transmitted to the trailer control valve (100), such that the trailer control valve (100) provides relay function triggered by primary circuit’s control pressure (41) in which pressure acts over the primary piston (104) and secondary circuit’s pressure (42) acts over the spring loaded secondary piston arrangement (105) for predominance feature between delivery chamber compartments, both the piston moves downwards and sits over the bonded valve (125) which opens the inlet path against the spring (126) and the supply pressure passes to delivery port (22) and at the same passes to spring loaded secondary piston arrangement (105) that delivery pressure acts over the predominance insert valve (121) against the compression spring (122), seals the check valve (118) which makes the predominance feature which can be variable by adjusting the adjustment screw (119), when the pressure overcomes the spring load and moves the predominance insert valve (121) and flows to the delivery air chamber (115) in that time pressure in the ratio of 1:1 and also in the event of failure of either primary or secondary circuits, the other circuit does the trailer braking, (iii) during parking brake ON state, when the GHCV is manipulated to the ON position, which causes the tractor's service brakes to engage, slowing down the tractor, and the trailer control valve senses the reduction in air pressure caused by the GHCV application and responds by reducing the air pressure in the trailer's brake system, which is achieved by the inversion function triggered by parking circuit control pressure (43) which breaks the balance between supply pressure (11) and parking control pressure (43), moves the inversion piston arrangement (108) upwards, and opens the inlet path to pass the supply pressure to delivery ports (22) to engage brake, and (iv) during emergency condition, such as during service brake application, the air pressure in the delivery line leakage, such that the emergency relay valve linked to trailer control valve (100) responds to the sudden pressure increase by quickly opening and allowing maximum air pressure to flow to the trailer brakes, thus helping to bring the vehicle to a stop as efficiently as possible which is achieved by the pilot operated 2/2 (130) valve which throttles the piston (111) against the compression spring (113) to restrict the supply flow, and triggers emergency relay valve to apply brakes.
Another aspect of the present invention is to provide a of working of a trailer control valve (100) for an air brake system, said method comprising steps of:
a. During trailer control valve (100) OFF state, both primary (104) and secondary piston (116) are held at top and inversion piston (108) is at balanced state by the pressure from parking control port (43) & supply pressure from supply port (11), such that the inlet valve of bonded valve (125) is closed by spring load (126) and therefore supply pressure not pass through valve to delivery (22), but the supply pressure flows to the supply delivery (21) for trailer supply line charging;
b. During service brake ON state, (Foot brake valve depressed condition), when the driver applies the foot brake in the towing vehicle, the air pressure in the system increases which is transmitted to the trailer control valve (100), such that the trailer control valve (100) provides relay function triggered by primary circuit’s control pressure (41) in which pressure acts over the primary piston (104) and secondary circuit’s pressure (42) acts over the spring loaded secondary piston arrangement (105) for predominance feature between delivery chamber compartments, both the piston moves downwards and sits over the bonded valve (125) which opens the inlet path against the spring (126) and the supply pressure passes to delivery port (22) and at the same passes to spring loaded secondary piston arrangement (105) that delivery pressure acts over the predominance insert valve (121) against the compression spring (122), seals the check valve (118) which makes the predominance feature which can be variable by adjusting the adjustment screw (119), when the pressure overcomes the spring load and moves the predominance insert valve (121) and flows to the delivery air chamber (115) in that time pressure in the ratio of 1:1 and also in the event of failure of either primary or secondary circuits, the other circuit does the trailer braking;
c. During parking brake ON state, when the GHCV is manipulated to the ON position, which causes the tractor's service brakes to engage, slowing down the tractor, and the trailer control valve senses the reduction in air pressure caused by the GHCV application and responds by reducing the air pressure in the trailer's brake system, which is achieved by the inversion function triggered by parking circuit control pressure (43) which breaks the balance between supply pressure (11) and parking control pressure (43), moves the inversion piston arrangement (108) upwards, and opens the inlet path to pass the supply pressure to delivery ports (22) to engage brake, and
d. during emergency condition, such as during service brake application, the air pressure in the delivery line leakage, such that the emergency relay valve linked to trailer control valve (100) responds to the sudden pressure increase by quickly opening and allowing maximum air pressure to flow to the trailer brakes, thus helping to bring the vehicle to a stop as efficiently as possible which is achieved by the pilot operated 2/2 (130) valve which throttles the piston (111) against the compression spring (113) to restrict the supply flow, and triggers emergency relay valve to apply brakes.

BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a view of a trailer control valve (100) of an air brake system.
Figure 2 is a detailed view of a trailer control valve (100) of an air brake system with ports.
Figure 3 is a detailed view of trailer control valve (100) of an air brake system.
Figure 3a is an internal view of upper portion of trailer control valve (100) of an air brake system.
Figure 3b is an internal view of lower portion of trailer control valve (100) of an air brake system.
DETAILED DESCRIPTION OF THE INVENTION
The present invention as embodied by a “a trailer control valve (100) of an air brake system and method thereof” succinctly fulfills the above-mentioned need[s] in the art. The present invention has objective[s] arising because of the above-mentioned need[s], said objective[s] having been enumerated herein above.
The following description is directed to an trailer control valve (100) of an air brake system and method thereof as much as the objective(s) of the present invention are enumerated, it will be obvious to a person skilled in the art that, the enumerated objective(s) are not exhaustive of the present invention in its entirety and are enclosed solely for the purpose of illustration. Further, the present invention encloses within its scope and purview, any structural alternative(s) and/or any functional equivalent(s) even though, such structural alternative(s) and/or any functional equivalent(s) are not mentioned explicitly herein or elsewhere, in the present disclosure. The present invention therefore encompasses also, any improvisation[s]/modification[s] applied to the structural alternative[s]/functional alternative[s] within its scope and purview. The present invention may be embodied in other specific form[s] without departing from the essential attributes thereof.
Furthermore, the terms and phrases used herein are not intended to be limiting, but rather are to provide an understandable description. Throughout this specification, the use of the word "comprise" and variations such as "comprises" and "comprising" may imply the inclusion of an element or elements not specifically recited.
The conventional trailer control valve (100) as discussed in the prior art have relatively slower response time lead to affect the overall braking performance, especially in emergency situations, offers limited precision in controlling the braking force on individual wheels, and requires regular maintenance leads to higher costs for repairs and maintenance. But in the case of present invention, an improved trailer control valve (100) provides more precise control over the application and release of brakes which contributes to better overall braking performance, especially in varying road and load conditions, and enhances the overall control of the entire vehicle combination that allows the driver to have better control over the braking system, ensuring a safer and more predictable response during various driving conditions.
Referring to Figure 1 to 3b, in an embodiment of the present invention, provides a trailer control valve (100) of an air brake system comprising: a valve body (101) provided with a supply port (11) receives compressed air from the vehicle's air compressor, delivery port (21 & 22) sends regulated air pressure to the trailer brakes, control port (41, 42 & 43) receives signals to control the valve operation, exhaust port allows the release of air pressure when needed; a primary piston (104); a spring loaded secondary piston arrangement (105); a spring; a inversion piston arrangement (108); a seal; an inversion piston (108) provided with inversion mechanism to change the direction of movement; a pilot operated 2/2valve (130), and a bonded valve (125) connected to one of the primary (104) or secondary pistons (116) and opens or closes based on the movement of that piston, and controls the flow of fluid to specific parts of the system. The trailer control valve (100) connected to both towing vehicle air brake system and the trailer's air brake system works under four different conditions: (i) during trailer control valve (100) OFF state, both primary (104) and secondary piston (116) are held at top and inversion piston (108) is at balanced state by the pressure from parking control port (43) & supply pressure from supply port (11), such that the inlet valve of bonded valve (125) is closed by spring load (126) and therefore supply pressure not pass through valve to delivery (22), but the supply pressure flows to the supply delivery (21) for trailer supply line charging, (ii) during service brake ON state, (Foot brake valve depressed condition), when the driver applies the foot brake in the towing vehicle, the air pressure in the system increases which is transmitted to the trailer control valve (100), such that the trailer control valve (100) provides relay function triggered by primary circuit’s control pressure (41) in which pressure acts over the primary piston (104) and secondary circuit’s pressure (42) acts over the spring loaded secondary piston arrangement (105) for predominance feature between delivery chamber compartments, both the piston moves downwards and sits over the bonded valve (125) which opens the inlet path against the spring (126) and the supply pressure passes to delivery port (22) and at the same passes to spring loaded secondary piston arrangement (105) that delivery pressure acts over the predominance insert valve (121) against the compression spring (122), seals the check valve (118) which makes the predominance feature which can be variable by adjusting the adjustment screw (119), when the pressure overcomes the spring load and moves the predominance insert valve (121) and flows to the delivery air chamber (115) in that time pressure in the ratio of 1:1 and also in the event of failure of either primary or secondary circuits, the other circuit does the trailer braking, (iii) during parking brake ON state, when the GHCV is manipulated to the ON position, which causes the tractor's service brakes to engage, slowing down the tractor, and the trailer control valve senses the reduction in air pressure caused by the GHCV application and responds by reducing the air pressure in the trailer's brake system, which is achieved by the inversion function triggered by parking circuit control pressure (43) which breaks the balance between supply pressure (11) and parking control pressure (43), moves the inversion piston arrangement (108) upwards, and opens the inlet path to pass the supply pressure to delivery ports (22) to engage brake, and (iv) during emergency condition, such as during service brake application, the air pressure in the delivery line leakage, such that the emergency relay valve linked to trailer control valve (100) responds to the sudden pressure increase by quickly opening and allowing maximum air pressure to flow to the trailer brakes, thus helping to bring the vehicle to a stop as efficiently as possible which is achieved by the pilot operated 2/2 (130) valve which throttles the piston (111) against the compression spring (113) to restrict the supply flow, and triggers emergency relay valve to apply brakes.
In one embodiment of the present invention, the primary piston (104) modulates the flow of air to the trailer brakes.
In another embodiment of the present invention, the secondary piston (116) works in conjunction with the primary piston (104) to control air pressure to the trailer brakes.
In another embodiment of the present invention, the spring provides a mechanical force to assist in controlling and maintaining air pressure in the system.
In another embodiment of the present invention, the seal prevents air leakage and ensures the integrity of the air pressure within the system.
Another embodiment of the present invention is to provide a method of working of a trailer control valve (100) for an air brake system, said method comprising steps of:
a. during trailer control valve (100) OFF state, both primary (104) and secondary piston (116) are held at top and inversion piston (108) is at balanced state by the pressure from parking control port (43) & supply pressure from supply port (11), such that the inlet valve of bonded valve (125) is closed by spring load (126) and therefore supply pressure not pass through valve to delivery (22), but the supply pressure flows to the supply delivery (21) for trailer supply line charging;
b. during service brake ON state, (Foot brake valve depressed condition), when the driver applies the foot brake in the towing vehicle, the air pressure in the system increases which is transmitted to the trailer control valve (100), such that the trailer control valve (100) provides relay function triggered by primary circuit’s control pressure (41) in which pressure acts over the primary piston (104) and secondary circuit’s pressure (42) acts over the spring loaded secondary piston arrangement (105) for predominance feature between delivery chamber compartments, both the piston moves downwards and sits over the bonded valve (125) which opens the inlet path against the spring (126) and the supply pressure passes to delivery port (22) and at the same passes to spring loaded secondary piston arrangement (105) that delivery pressure acts over the predominance insert valve (121) against the compression spring (122), seals the check valve (118) which makes the predominance feature which can be variable by adjusting the adjustment screw (119), when the pressure overcomes the spring load and moves the predominance insert valve (121) and flows to the delivery air chamber (115) in that time pressure in the ratio of 1:1 and also in the event of failure of either primary or secondary circuits, the other circuit does the trailer braking;
c. during parking brake ON state, when the GHCV is manipulated to the ON position, which causes the tractor's service brakes to engage, slowing down the tractor, and the trailer control valve senses the reduction in air pressure caused by the GHCV application and responds by reducing the air pressure in the trailer's brake system, which is achieved by the inversion function triggered by parking circuit control pressure (43) which breaks the balance between supply pressure (11) and parking control pressure (43), moves the inversion piston arrangement (108) upwards, and opens the inlet path to pass the supply pressure to delivery ports (22) to engage brake, and
d. during emergency condition, such as during service brake application, the air pressure in the delivery line leakage, such that the emergency relay valve linked to trailer control valve (100) responds to the sudden pressure increase by quickly opening and allowing maximum air pressure to flow to the trailer brakes, thus helping to bring the vehicle to a stop as efficiently as possible which is achieved by the pilot operated 2/2 (130) valve which throttles the piston (111) against the compression spring (113) to restrict the supply flow, and triggers emergency relay valve to apply brakes.
WORKING EXAMPLE
An exemplary embodiment discloses a trailer control valve (100) of an air brake system comprising: a valve body (101) provided with a supply port (11) receives compressed air from the vehicle's air compressor, delivery port (21 & 22) sends regulated air pressure to the trailer brakes, control port (41, 42 & 43) receives signals to control the valve operation, exhaust port allows the release of air pressure when needed; a primary piston (104); a spring loaded secondary piston arrangement (105); a spring; an inversion piston arrangement (108); a seal; an inversion piston (108) provided with inversion mechanism to change the direction of movement; a pilot operated 2/2valve (130), and a bonded valve (125) connected to one of the primary (104) or secondary pistons (116) and opens or closes based on the movement of that piston, and controls the flow of fluid to specific parts of the system.
The trailer control valve (100) connected to both towing vehicle air brake system and the trailer's air brake system works under four different conditions:
(i) During trailer control valve (100) OFF state, both primary (104) and secondary piston (116) are held at top and inversion piston (108) is at balanced state by the pressure from parking control port (43) & supply pressure from supply port (11), such that the inlet valve of bonded valve (125) is closed by spring load (126) and therefore supply pressure not pass through valve to delivery (22), but the supply pressure flows to the supply delivery (21) for trailer supply line charging,
(ii) During service brake ON state, (Foot brake valve depressed condition), when the driver applies the foot brake in the towing vehicle, the air pressure in the system increases which is transmitted to the trailer control valve (100), such that the trailer control valve (100) provides relay function triggered by primary circuit’s control pressure (41) in which pressure acts over the primary piston (104) and secondary circuit’s pressure (42) acts over the spring loaded secondary piston arrangement (105) for predominance feature between delivery chamber compartments, both the piston moves downwards and sits over the bonded valve (125) which opens the inlet path against the spring (126) and the supply pressure passes to delivery port (22) and at the same passes to spring loaded secondary piston arrangement (105) that delivery pressure acts over the predominance insert valve (121) against the compression spring (122), seals the check valve (118) which makes the predominance feature which can be variable by adjusting the adjustment screw (119), when the pressure overcomes the spring load and moves the predominance insert valve (121) and flows to the delivery air chamber (115) in that time pressure in the ratio of 1:1 and also in the event of failure of either primary or secondary circuits, the other circuit does the trailer braking,
(iii) During parking brake ON state, when the GHCV is manipulated to the ON position, which causes the tractor's service brakes to engage, slowing down the tractor, and the trailer control valve senses the reduction in air pressure caused by the GHCV application and responds by reducing the air pressure in the trailer's brake system, which is achieved by the inversion function triggered by parking circuit control pressure (43) which breaks the balance between supply pressure (11) and parking control pressure (43), moves the inversion piston arrangement (108) upwards, and opens the inlet path to pass the supply pressure to delivery ports (22) to engage brake, and
(iv) During emergency condition, such as during service brake application, the air pressure in the delivery line leakage, such that the emergency relay valve linked to trailer control valve (100) responds to the sudden pressure increase by quickly opening and allowing maximum air pressure to flow to the trailer brakes, thus helping to bring the vehicle to a stop as efficiently as possible which is achieved by the pilot operated 2/2 (130) valve which throttles the piston (111) against the compression spring (113) to restrict the supply flow, and triggers emergency relay valve to apply brakes.

ADVANTAGE OF THE PRESENT INVENTION
The present invention relates to a trailer control valve (100) of an air brake system which controls and regulates the air pressure supplied to the trailer brakes. Advantageously, the present invention achieving better control and stability when maneuvering the entire combination vehicle, and maintains proper air pressure and ensures effective braking performance.
The present invention relates to a trailer control valve (100) which provides proportional control to reduce wear and tear on the trailer brakes, thus prevents abrupt and excessive braking forces that can lead to premature brake component wear.
The present invention relates to trailer control valve (100) which ensures that both the tractor and trailer brakes respond appropriately to bring the entire vehicle combination to a stop efficiently and safely in emergency braking situations.
The present invention relates to a trailer control valve (100) which provides smooth and proportional braking thus enhances driver comfort.
It will be apparent to a person skilled in the art that the above description is for illustrative purposes only and should not be considered as limiting. Various modifications, additions, alterations, and improvements without deviating from the spirit and the scope of the invention may be made by a person skilled in the art.

LIST OF NUMERALS:
(100). Trailer control valve
(101). Valve body
(102). Cartridge piston
(103). Top cover
(104). Primary piston
(105). Spring loaded secondary piston arrangement
(106). Nut
(107). Bolt
(108). Inversion piston arrangement
(109). Exhaust silencer
(110). Exhaust cover
(111). Piston
(112). Retainer
(113). Compression spring
(114). Circlip
(115). Delivery air chamber
(116). Secondary piston
(117). Predominance cover
(118). Check valve
(119). Adjustment screw
(120). Circlip
(121). Predominance insert valve
(122). Compression spring
(123). Poppet
(124). Inversion piston
(125). Bonded valve
(126). Compression spring
(127). Retainer
(128). Plunger
(129). Stud
(130). Pilot operated 2/2 valve
, Claims:WE CLAIM:
1. A trailer control valve (100) for air brake system, comprising:
a. a valve body (101) provided with a supply port (11) receives compressed air from the vehicle's air compressor, delivery port (21 & 22) sends regulated air pressure to the trailer brakes, control port (41, 42 & 43) receives signals to control the valve operation, exhaust port allows the release of air pressure when needed;
b. a primary piston (104);
c. a spring loaded secondary piston arrangement (105);
d. a spring;
e. a inversion piston arrangement (108);
f. a seal;
g. an inversion piston (108) provided with inversion mechanism to change the direction of movement;
h. a pilot operated 2/2valve (130), and
i. a bonded valve (125) connected to one of the primary (104) or secondary pistons (116) and opens or closes based on the movement of that piston, and controls the flow of fluid to specific parts of the system,
wherein the trailer control valve (100) connected to both towing vehicle air brake system and the trailer's air brake system works under four different conditions:
(i) During trailer control valve (100) OFF state, both primary (104) and secondary piston (116) are held at top and inversion piston (108) is at balanced state by the pressure from parking control port (43) & supply pressure from supply port (11), such that the inlet valve of bonded valve (125) is closed by spring load (126) and therefore supply pressure not pass through valve to delivery (22), but the supply pressure flows to the supply delivery (21) for trailer supply line charging,
(ii) During service brake ON state, (Foot brake valve depressed condition), when the driver applies the foot brake in the towing vehicle, the air pressure in the system increases which is transmitted to the trailer control valve (100), such that the trailer control valve (100) provides relay function triggered by primary circuit’s control pressure (41) in which pressure acts over the primary piston (104) and secondary circuit’s pressure (42) acts over the spring loaded secondary piston arrangement (105) for predominance feature between delivery chamber compartments, both the piston moves downwards and sits over the bonded valve (125) which opens the inlet path against the spring (126) and the supply pressure passes to delivery port (22) and at the same passes to spring loaded secondary piston arrangement (105) that delivery pressure acts over the predominance insert valve (121) against the compression spring (122), seals the check valve (118) which makes the predominance feature which can be variable by adjusting the adjustment screw (119), when the pressure overcomes the spring load and moves the predominance insert valve (121) and flows to the delivery air chamber (115) in that time pressure in the ratio of 1:1 and also in the event of failure of either primary or secondary circuits, the other circuit does the trailer braking,
(iii) During parking brake ON state, when the GHCV is manipulated to the ON position, which causes the tractor's service brakes to engage, slowing down the tractor, and the trailer control valve senses the reduction in air pressure caused by the GHCV application and responds by reducing the air pressure in the trailer's brake system, which is achieved by the inversion function triggered by parking circuit control pressure (43) which breaks the balance between supply pressure (11) and parking control pressure (43), moves the inversion piston arrangement (108) upwards, and opens the inlet path to pass the supply pressure to delivery ports (22) to engage brake, and
(iv) during emergency condition, such as during service brake application, the air pressure in the delivery line leakage, such that the emergency relay valve linked to trailer control valve (100) responds to the sudden pressure increase by quickly opening and allowing maximum air pressure to flow to the trailer brakes, thus helping to bring the vehicle to a stop as efficiently as possible which is achieved by the pilot operated 2/2 (130) valve which throttles the piston (111) against the compression spring (113) to restrict the supply flow, and triggers emergency relay valve to apply brakes.

2. The trailer control valve (100) as claimed in claim 1, wherein the primary piston (104) modulates the flow of air to the trailer brakes.

3. The trailer control valve as claimed in claim 1, wherein the secondary piston (116) works in conjunction with the primary piston (104) to control air pressure to the trailer brakes.

4. The trailer control valve (100) as claimed in claim 1, wherein the spring provides a mechanical force to assist in controlling and maintaining air pressure in the system.

5. The trailer control valve (100) as claimed in claim 1, wherein the seal prevents air leakage and ensures the integrity of the air pressure within the system.

6. A method of working of a trailer control valve (100) for an air brake system as claimed in claim 1, said method comprising steps of:

a. during trailer control valve (100) OFF state, both primary (104) and secondary piston (116) are held at top and inversion piston (108) is at balanced state by the pressure from parking control port (43) & supply pressure from supply port (11), such that the inlet valve of bonded valve (125) is closed by spring load (126) and therefore supply pressure not pass through valve to delivery (22), but the supply pressure flows to the supply delivery (21) for trailer supply line charging;
b. during service brake ON state, (Foot brake valve depressed condition), when the driver applies the foot brake in the towing vehicle, the air pressure in the system increases which is transmitted to the trailer control valve (100), such that the trailer control valve (100) provides relay function triggered by primary circuit’s control pressure (41) in which pressure acts over the primary piston (104) and secondary circuit’s pressure (42) acts over the spring loaded secondary piston arrangement (105) for predominance feature between delivery chamber compartments, both the piston moves downwards and sits over the bonded valve (125) which opens the inlet path against the spring (126) and the supply pressure passes to delivery port (22) and at the same passes to spring loaded secondary piston arrangement (105) that delivery pressure acts over the predominance insert valve (121) against the compression spring (122), seals the check valve (118) which makes the predominance feature which can be variable by adjusting the adjustment screw (119), when the pressure overcomes the spring load and moves the predominance insert valve (121) and flows to the delivery air chamber (115) in that time pressure in the ratio of 1:1 and also in the event of failure of either primary or secondary circuits, the other circuit does the trailer braking;
c. during parking brake ON state, when the GHCV is manipulated to the ON position, which causes the tractor's service brakes to engage, slowing down the tractor, and the trailer control valve senses the reduction in air pressure caused by the GHCV application and responds by reducing the air pressure in the trailer's brake system, which is achieved by the inversion function triggered by parking circuit control pressure (43) which breaks the balance between supply pressure (11) and parking control pressure (43), moves the inversion piston arrangement (108) upwards, and opens the inlet path to pass the supply pressure to delivery ports (22) to engage brake, and
d. during emergency condition, such as during service brake application, the air pressure in the delivery line leakage, such that the emergency relay valve linked to trailer control valve (100) responds to the sudden pressure increase by quickly opening and allowing maximum air pressure to flow to the trailer brakes, thus helping to bring the vehicle to a stop as efficiently as possible which is achieved by the pilot operated 2/2 (130) valve which throttles the piston (111) against the compression spring (113) to restrict the supply flow, and triggers emergency relay valve to apply brakes.
-SD-
Dated this 14th day of March 2024 Kalyanchand Jhabakh (IN/PA830)
Agent for applicant.