Description:INVERSION RELAY VALVE FOR AIR BRAKE SYSTEM AND METHOD THEREOF

FIELF OF THE INVENTION
The present invention relates to a relay valve for air brake systems. More particularly, the present invention relates to an inversion relay valve for air brake system for vehicle which prevents compounding of the service brakes and the spring brakes and modulates application of the spring brakes in the event of failure in service brake circuit. Advantageously, the present invention shortens the response of a braking process.
BACKGROUND OF THE INVENTION
Braking system in an automobile serves as a fundamental element of both safety and control. The mechanisms and components are designed to effectively slow down or halt a vehicle, translating kinetic energy into heat through friction. Brakes are essential for navigating traffic, negotiating corners, and responding to sudden obstacles on the road.
With advancements in technology, an air brake or, more formally, a compressed-air-brake system is introduced, is a type of friction brake for vehicles in which compressed air pressing on a piston is used to both release the parking/emergency brakes in order to move the vehicle, and also to apply pressure to the brake pads or brake shoes to slow and stop the vehicle. Air brakes are used in large heavy vehicles, particularly those having multiple trailers which must be linked into the brake system, such as trucks, buses, trailers, and semi-trailers, in addition to their use in railroad trains.
In an air brake system, the inversion relay valve is a critical component of commercial vehicles such as trucks and buses. It serves as a control valve that helps activate and release the brakes on the vehicle. The purpose of the inversion relay valve is to expedite the application and release of the spring brakes. Spring brakes are a type of brake system that uses mechanical force stored in springs to engage the brakes when the air pressure drops below a certain level or during emergency situations.
Some of the prior arts are:
US 20030075973 discloses a combination inversion and relay or quick release valve assembly comprising a combination valve assembly provides dual functionality within a single valve housing. In one example, the valve operates as a combination inversion valve and quick release valve. In another example, the combination valve operates as an inversion valve and a relay valve. The valve is particularly useful for controlling the operation of a spring applied, air release brake actuator in a heavy vehicle braking arrangement. A valve designed according to this invention preferably also provides anti-compounding features.
US4121873 discloses a vehicle air brake system with emergency features comprises front service and parking brakes, and rear service and parking brakes, includes separate front service, rear service and parking air systems. In the event of a failure in either service air system, normal operation of the service brake control will automatically operate the parking brakes associated with the failed service brakes.
IN373/MUM/2013 discloses an anti-compounding hand brake valve comprises handle, an inlet, an exhaust valve, a signal port and an outlet. The handle is operable to and from the first position and a second position. The anti-compounding hand brake operates without affecting basic braking system performance as the anti-compounding hand brake valve is connected only to the spring brake compartment that prevents complete failure of the air brake system in case of the failure of the anti-compounding hand brake valve.
IN537/CHE/2003 discloses an inversion relay valve for the air brake system of a motor vehicle comprising a valve body provided with a spring brake control port, a primary service port, a secondary service port, a reservoir port, a delivery port and an exhaust port, the valve body housing a spring loaded primary piston and an relay piston; a diaphragm valve for the spring brake control port and an air chamber provided above the primary piston; a spring-loaded in let/exhaust valve, characterized by a spring-loaded ring piston surrounding the relay piston, said ring piston being located in an annular space provided in the valve body adjacent the relay piston, and movable, independently of the relay piston between a first stop on the valve body and a second stop on the relay piston.
IN 796/CHE/2003 discloses an inversion quick release valve with in-built quick release mechanism for motor vehicle air braking system, comprising a valve body, a cover, a piston and a piston ring incorporated within the valve body, an integrated double check valve, being placed in the valve body, and connected to inlet/exhaust valve for the anti-compounding function, the inlet/exhaust valve admit air into system and exhaust air from the system at specified condition, a floating valve having a valve seat, designed for quick release function. A graduated spring positioned in the piston balances against air pressure for releasing spring brake in the normal spring brake application, the quick releasing mechanism being characterized by the floating valve seat with exhaust air into atmosphere suddenly for faster spring brake application, the inlet valve floating up and down at appropriate levels for activating the quick release function and when the valve seat moves up air goes into the system and when the valve goes down air from the system is exhausted for spring brake application.
However, the conventional inversion relay valve as discussed in the prior art requires regular maintenance and inspection to ensure proper functioning which increases maintenance cost and effort required to keep the air brake system in good working condition and provides limited control options.
Accordingly, there is a need for an improved inversion relay valve for air brake system which prevents compounding of the service brakes and the spring brakes and modulates application of the spring brakes in the event of failure in service brake circuit and shortens the response of a braking process, thus ensures that the vehicle is brought to a stop safely and quickly even if there is a failure in the service brake system.
OBJECT OF THE INVENTION
The principal object of the present invention is to provide an inversion relay valve for air brake systems for motor vehicles.
Another object of this invention is to provide an inversion relay valve which reduces the braking time by quickly redirecting air pressure from the service brake line to the emergency brake line, and quickly engages the brakes and reduces stopping distances, thereby enhancing the safety of the vehicle.
Another object of this invention is to distribute the braking force evenly across all the wheels by balancing the air pressure between the service and emergency brake lines.
SUMMARY OF THE INVENTION
It is a primary aspect of the present invention to provide an inversion relay valve (100) of an air brake system, comprising: a valve body (101) having two input supply ports (11, 12), four delivery ports (21, 22, 23, 24) to control the spring side of spring brake actuator, a primary service brake control port (41), a secondary service brake control port (42) and a parking brake control port (43); a top cover (102) integrated to valve body (101) by fasteners (103); a relay piston (104) controls delivery pressure by moving accordingly to parking control pressure in parking brake control port (43); an inversion valve arrangement (105) provided with a graduating spring (106) to limit the delivery pressure to defined value; a balance valve piston (107) provided with quick release arrangement (108) to control the delivery pressure; a silencer assembly (109), and a check valve (127) placed at the bottom of parking brake control port (43) inside the valve body (101) which allows the higher air pressure from either parking brake control port (43) or primary service brake control port (41) to parking brake control chamber (118).
The inversion relay valve (100) fixed at the rear axle of the vehicle works under four different conditions: (i) during parking brake OFF state, the continuous air pressure from port 2 of graduated hand control valve (GHCV) at park brake valve control port (43) seals the check valve (127) against the passage of primary service control port (41) and flows into the cavity on control chamber (118) and this air-pressure forces the spring-loaded relay piston (104) to move downward against a compression spring (110) and contact the bonded valve (111) which further moves downward and contacts the exhaust port, and opens the inlet passage against a compression spring (112), thereby allowing air to flow from the reservoir port to the delivery ports, thus the parking brakes are released, (ii) during parking brake ON state, the air pressure at the park brake valve control port (43) and on top of the spring-loaded relay piston (104) is exhausted through the park brake valve control port, the spring-loaded relay piston (104) then moves upward, thus opening the exhaust port and sealing the inlet, and air-from the delivery ports is then exhausted, thus applying parking brakes, (iii) during anti-compounding braking, in case of absence of signal form hand brake valve at park brake valve control port (43) that is parking brake is already applied, when foot brake is operated, the air entering the service primary control port (41) acts over the check valve (127) which allows the higher air pressure and seals the passage against the park brake valve control port (43) and flows to the top of the spring-loaded relay piston (104), this air pressure forces the spring-loaded relay piston (104) to move downward against a compression spring (110) and contacts the bonded valve (111) . Further movement of the relay piston (104) opens the inlet passage thereby allowing air to flow from the reservoir port to the delivery ports (21-24), thus the parking brakes are released thereby preventing the compounding of the service brake and the parking brake, and (iv) during primary service brake failure condition, in case of primary service signal failure at spring brake chambers control port (41) when the foot brake is depressed, the inversion relay valve (100) facilitates the air pressure at the secondary service control port (42) to trigger the inversion valve arrangement through a pilot operated balance valve piston (107) & breathing chamber (124) , this air pressure moves the balance valve piston downward against a spring and deflects a diaphragm (121) which contact with valve seat closes the exhaust path and flows into the inversion chamber (126), thus forces the inversion valve arrangement (105) to move downward further thereby exhausting air from the delivery ports (21-24) and applying the spring brakes, such that the air released from the spring brakes is proportional to the pressure at secondary service control port (42) thus providing the driver with a modulated application of the spring brakes.
Another aspect of the present invention is to provide a method of working of inversion relay valve (100) for air brake system, said method comprises steps of:
a. during parking brake OFF state, the continuous air pressure from port 2 of graduated hand control valve (GHCV) at park brake valve control port (43) seals the check valve (127) against the passage of primary service control port (41) and flows into the cavity on control chamber (118) and this air-pressure forces the spring-loaded relay piston (104) to move downward against a compression spring (110) and contact the bonded valve (111) which further moves downward and contacts the exhaust port, and opens the inlet passage against a compression spring (112), thereby allowing air to flow from the reservoir port to the delivery ports, thus the parking brakes are released.
b. during parking brake ON state, the air pressure at the park brake valve control port (43) and on top of the spring-loaded relay piston (104) is exhausted through the park brake valve control port, the spring-loaded relay piston (104) then moves upward, thus opening the exhaust port and sealing the inlet, and air-from the delivery ports is then exhausted, thus applying parking brakes.
c. during anti-compounding braking, in case of absence of signal form hand brake valve at park brake valve control port (43) that is parking brake is already applied, when foot brake is operated, the air entering the service primary control port (41) acts over the check valve (127) which allows the higher air pressure and seals the passage against the park brake valve control port (43) and flows to the top of the spring-loaded relay piston (104), this air pressure forces the spring-loaded relay piston (104) to move downward against a compression spring (110) and contacts the bonded valve (111) . Further movement of the relay piston (104) opens the inlet passage thereby allowing air to flow from the reservoir port to the delivery ports (21-24), thus the parking brakes are released thereby preventing the compounding of the service brake and the parking brake and,
d. during primary service brake failure condition, in case of primary service signal failure at spring brake chambers control port (41) when the foot brake is depressed, the inversion relay valve (100) facilitates the air pressure at the secondary service control port (42) to trigger the inversion valve arrangement through a pilot operated balance valve piston (107) & breathing chamber (124), this air pressure moves the balance valve piston downward against a spring and deflects a diaphragm (121) which contact with valve seat closes the exhaust path and flows into the inversion chamber (126), thus forces the inversion valve arrangement (105) to move downward further thereby exhausting air from the delivery ports (21-24) and applying the spring brakes, such that the air released from the spring brakes is proportional to the pressure at secondary service control port (42) thus providing the driver with a modulated application of the spring brakes.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1a is a front view of an inversion relay valve of an air brake system.
Figure 1b is a side view of an inversion relay valve of an air brake system.
Figure 2a is an internal view of an inversion relay valve of an air brake system.
Figure 2b is a detailed view of an inversion relay valve of an air brake system.
Figure 3a is a view of detailed view of an inversion relay valve of an air brake system.
Figure 3b is a view of detailed view of an inversion relay valve of an air brake system.
DETAILED DESCRIPTION OF THE INVENTION
The present invention as embodied by a “an inversion relay valve 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 inversion relay valve 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 inversion relay valve requires regular maintenance and inspection to ensure proper functioning which increases maintenance cost and effort required to keep the air brake system in good working condition and provides limited control options. But in the case of present invention, an improved inversion relay valve reduces the braking time by quickly redirecting air pressure from the service brake line to the emergency brake line, and quickly engages the brakes and reduces stopping distances, thereby enhancing the safety of the vehicle.
Referring to Figure 1a to 3b, in an embodiment of the present invention, provides an inversion relay valve (100) of an air brake system comprising: a valve body (101) having two input supply ports (11, 12), four delivery ports (21, 22, 23, 24) to control the spring side of spring brake actuator, a primary service brake control port (41), a secondary service brake control port (42) and a parking brake control port (43); a top cover (102) integrated to valve body (101) by fasteners (103); a relay piston (104) controls delivery pressure by moving accordingly to parking control pressure in parking brake control port (43); an inversion valve arrangement (105) provided with a graduating spring (106) to limit the delivery pressure to defined value; a balance valve piston (107) provided with quick release arrangement (108) to control the delivery pressure; a silencer assembly (109), and a check valve (127) placed at the bottom of parking brake control port (43) inside the valve body (101) which allows the higher air pressure from either parking brake control port (43) or primary service brake control port (41) to parking brake control chamber (118).
The inversion relay valve (100) fixed at the rear axle of the vehicle works under four different conditions:
(i) during parking brake OFF state, the continuous air pressure from port 2 of graduated hand control valve (GHCV) at park brake valve control port (43) seals the check valve (127) against the passage of primary service control port (41) and flows into the cavity on control chamber (118) and this air-pressure forces the spring-loaded relay piston (104) to move downward against a compression spring (110) and contact the bonded valve (111) which further moves downward and contacts the exhaust port, and opens the inlet passage against a compression spring (112), thereby allowing air to flow from the reservoir port to the delivery ports, thus the parking brakes are released.
(ii) during parking brake ON state, the air pressure at the park brake valve control port (43) and on top of the spring-loaded relay piston (104) is exhausted through the park brake valve control port, the spring-loaded relay piston (104) then moves upward, thus opening the exhaust port and sealing the inlet, and air-from the delivery ports is then exhausted, thus applying parking brakes.
(iii) during anti-compounding braking, in case of absence of signal form hand brake valve at park brake valve control port (43) that is parking brake is already applied, when foot brake is operated, the air entering the service primary control port (41) acts over the check valve (127) which allows the higher air pressure and seals the passage against the park brake valve control port (43) and flows to the top of the spring-loaded relay piston (104), this air pressure forces the spring-loaded relay piston (104) to move downward against a compression spring (110) and contacts the bonded valve (111) . Further movement of the relay piston (104) opens the inlet passage thereby allowing air to flow from the reservoir port to the delivery ports (21-24), thus the parking brakes are released thereby preventing the compounding of the service brake and the parking brake and,
(iv) during primary service brake failure condition, in case of primary service signal failure at spring brake chambers control port (41) when the foot brake is depressed, the inversion relay valve (100) facilitates the air pressure at the secondary service control port (42) to trigger the inversion valve arrangement through a pilot operated balance valve piston (107) & breathing chamber (124) , this air pressure moves the balance valve piston downward against a spring and deflects a diaphragm (121) which contact with valve seat closes the exhaust path and flows into the inversion chamber (126), thus forces the inversion valve arrangement (105) to move downward further thereby exhausting air from the delivery ports (21-24) and applying the spring brakes, such that the air released from the spring brakes is proportional to the pressure at secondary service control port (42) thus providing the driver with a modulated application of the spring brakes.
In one embodiment of the present invention, the relay Piston (104) over the compression spring (110) and the inversion valve arrangement (105) comprises of a bonded valve (111), a compression spring (112) to provide sealing load, a spring guide (113), a retainer (114) with circlip (115) and sealing rings (116) (117) translate against the graduating spring (106) inside the valve body (101) to control the delivery air pressure according to air pressure in parking brake control chamber (118).
In one embodiment of the present invention, the balance valve piston (107) over the compression spring (119) with an adaptor (120) and a diaphragm (121) over the valve seat (122) with circlip (123) assembled in a breathing chamber (124) inside the valve body (101) which is connected by a cross-hole to balance chamber (125) and inversion chamber (126).
In one embodiment of the present invention, the balance valve piston (107) translates against the compression spring (119) and allows the air from the secondary service brake control port (42) during the primary service brake control port (41) failure condition to the inversion chamber (126) through the breathing chamber (124) to translate the inversion valve arrangement (105) against graduating spring (106) and in turn to exhaust the delivery pressure.
In one embodiment of the present invention, the spring-loaded relay piston (104) moves back and forth inside the valve body to control air pressure in the system.
In another embodiment of the present invention, the springs provide counteracting forces, assisting in the smooth operation of the pistons.
In another embodiment of the present invention, the inversion valve arrangement (105) moves back and forth inside the valve body to control air pressure in the system.
In another embodiment of the present invention, the inversion valve arrangement (105) is connected to a balance valve piston (107) and quick release valve arrangement (124).
In another embodiment of the present invention, the spring-loaded relay piston (104) and the inversion valve arrangement (105) which consists of the caged graduating spring (106) to provide the necessary load to achieve pressure limiting function.
Another embodiment of the present invention is to provide a method of working of inversion relay valve (100) for air brake system, said method comprises steps of:
a. during parking brake OFF state, flowing the continuous air pressure from port 2 of graduated hand control valve (GHCV) at park brake valve control port (43) that seals the check valve (127) against the passage of primary service control port (41) and flows into the cavity on control chamber (118) and this air-pressure forces the spring-loaded relay piston (104) to move downward against a compression spring (110) and contact the bonded valve (111) which further moves downward and contacts the exhaust port, and opens the inlet passage against a compression spring (112), thereby allowing air to flow from the reservoir port to the delivery ports, thus the parking brakes are released.
b. during parking brake ON state, exhausting the air pressure at the park brake valve control port (43) and on top of the spring-loaded relay piston (104) through the park brake valve control port, the spring-loaded relay piston then moves upward, thus opening the exhaust port and sealing the inlet, and air-from the delivery ports is then exhausted, thus applying parking brakes.
c. during anti-compounding braking, in case of absence of signal form hand brake valve at park brake valve control port (43) that is parking brake is already applied, when foot brake is operated, when foot brake is operated, the air entering the service primary control port (41) acts over the check valve (127) which allows the higher air pressure and seals the passage against the park brake valve control port (43) and flows to the top of the spring-loaded relay piston (104), this air pressure forces the spring-loaded relay piston (104) to move downward against a compression spring (110) and contacts the bonded valve (111) . Further movement of the relay piston (104) opens the inlet passage thereby allowing air to flow from the reservoir port to the delivery ports (21-24), thus the parking brakes are released thereby preventing the compounding of the service brake and the parking brake.
d. during primary service brake failure condition, in case of primary service signal failure at spring brake chambers control port (41) when the foot brake is depressed, the inversion relay valve (100) facilitates the air pressure at the secondary service control port (42) to trigger the inversion valve arrangement (105) through a pilot operated balance valve piston (107) & breathing chamber (124) , this air pressure moves the balance valve piston (107) piston downward against a compression spring and deflects a diaphragm (121) which contact with valve seat closes the exhaust path and flows into the inversion chamber (126), thus forces the inversion valve arrangement (105) to move downward further thereby exhausting air from the delivery ports (21-24) and applying the spring brakes, such that the air released from the spring brakes is proportional to the pressure at secondary service control port (42) thus providing the driver with a modulated application of the spring brakes.
WORKING EXAMPLE
An exemplary embodiment discloses an inversion relay valve (100) of an air brake system comprising: a valve body (101) having two input supply ports (11, 12), four delivery ports (21, 22, 23, 24) to control the spring side of spring brake actuator, a primary service brake control port (41), a secondary service brake control port (42) and a parking brake control port (43); a top cover (102) integrated to valve body (101) by fasteners (103); a relay piston (104) controls delivery pressure by moving accordingly to parking control pressure in parking brake control port (43); an inversion valve arrangement (105) provided with a graduating spring (106) to limit the delivery pressure to defined value; a balance valve piston (107) provided with quick release arrangement (108) to control the delivery pressure; a silencer assembly (109), and a check valve (127) placed at the bottom of parking brake control port (43) inside the valve body (101) which allows the higher air pressure from either parking brake control port (43) or primary service brake control port (41) to parking brake control chamber (118).
The inversion relay valve (100) fixed at the rear axle of the vehicle works under four different conditions:
during parking brake OFF state, the continuous air pressure from port 2 of graduated hand control valve (GHCV) at park brake valve control port (43) seals the check valve (127) against the passage of primary service control port (41) and flows into the cavity on control chamber (118) and this air-pressure forces the spring-loaded relay piston (104) to move downward against a compression spring (110) and contact the bonded valve (111) which further moves downward and contacts the exhaust port, and opens the inlet passage against a compression spring (112), thereby allowing air to flow from the reservoir port to the delivery ports, thus the parking brakes are released.
during parking brake ON state, the air pressure at the park brake valve control port (43) and on top of the spring-loaded relay piston (104) is exhausted through the park brake valve control port, the spring-loaded relay piston (104) then moves upward, thus opening the exhaust port and sealing the inlet, and air-from the delivery ports is then exhausted, thus applying parking brakes.
during anti-compounding braking, in case of absence of signal form hand brake valve at park brake valve control port (43) that is parking brake is already applied, when foot brake is operated, the air entering the service primary control port (41) acts over the check valve (127) which allows the higher air pressure and seals the passage against the park brake valve control port (43) and flows to the top of the spring-loaded relay piston (104), this air pressure forces the spring-loaded relay piston (104) to move downward against a compression spring (110) and contacts the bonded valve (111) . Further movement of the relay piston (104) opens the inlet passage thereby allowing air to flow from the reservoir port to the delivery ports (21-24), thus the parking brakes are released thereby preventing the compounding of the service brake and the parking brake.
during primary service brake failure condition, in case of primary service signal failure at spring brake chambers control port (41) when the foot brake is depressed, the inversion relay valve (100) facilitates the air pressure at the secondary service control port (42) to trigger the inversion valve arrangement through a pilot operated balance piston (107) & breathing chamber (124) , this air pressure moves the balance valve piston downward against a spring and deflects a diaphragm (121) which contact with valve seat closes the exhaust path and flows into the inversion chamber (126), thus forces the inversion valve arrangement (105) to move downward further thereby exhausting air from the delivery ports (21-24) and applying the spring brakes, such that the air released from the spring brakes is proportional to the pressure at secondary service control port (42) thus providing the driver with a modulated application of the spring brakes.
ADVANTAGE OF THE PRESENT INVENTION
The present invention relates to an inversion relay valve of an air brake system which reduces the braking time by quickly redirecting air pressure from the service brake line to the emergency brake line, and quickly engages the brakes and reduces stopping distances, thereby enhancing the safety of the vehicle.
The present invention relates to an inversion relay valve which distributes the braking force evenly across all the wheels by balancing the air pressure between the service and emergency brake lines.
The present invention relates to an inversion relay valve which ensures that the brakes are activated and released in a timely manner, providing the necessary control and stopping power for commercial vehicles.
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). Inversion relay valve
(101). Valve body
(102). Top cover
(103). Fasteners
(104). Relay piston
(105). Inversion valve arrangement
(106). Graduating spring
(107). Balance valve piston
(108). Quick release arrangement
(109). Silencer assembly
(110). Compression spring
(111). Bonded valve
(112). Compression spring
(113). Spring guide
(114). Retainer
(115). Circlip
(116) & (117). Sealing rings
(118). Control chamber
(119). Compression spring
(120). Adaptor
(121). Diaphragm
(122). Valve seat
(123). Circlip
(124). Breathing chamber
(125). Balance chamber
(126). Inversion chamber
(127). Check valve
(128), (129), (130) & (131) Sealing rings
(132). Filter
(133). Mesh

, C , Claims:WE CLAIM:
1. An inversion relay valve (100) for pneumatic brake system, comprising:
a. valve body (101) having two input supply ports (11, 12), four delivery ports (21, 22, 23, 24) to control the spring side of spring brake actuator, a primary service brake control port (41), a secondary service brake control port (42) and a parking brake control port (43);
b. a top cover (102) integrated to valve body (101) by fasteners (103);
c. a relay piston (104) controls delivery pressure by moving accordingly to parking control pressure in parking brake control port (43);
d. an inversion valve arrangement (105) provided with a graduating spring (106) to limit the delivery pressure to defined value;
e. a balance valve piston (107) provided with quick release arrangement (108) to control the delivery pressure;
f. a silencer assembly (109), and
g. a check valve (127) placed at the bottom of parking brake control port (43) inside the valve body (101) which allows the higher air pressure from either parking brake control port (43) or primary service brake control port (41) to parking brake control chamber (118).
Characterized in that: the inversion relay valve (100) fixed at the rear axle of the vehicle works under four different conditions:
(v) during parking brake OFF state, the continuous air pressure from port 2 of graduated hand control valve (GHCV) at park brake valve control port (43) seals the check valve (127) against the passage of primary service control port (41) and flows into the cavity on control chamber (118) and this air-pressure forces the spring-loaded relay piston (104) to move downward against a compression spring (110) and contact the bonded valve (111) which further moves downward and contacts the exhaust port, and opens the inlet passage against a compression spring (112), thereby allowing air to flow from the reservoir port to the delivery ports, thus the parking brakes are released.
(vi) during parking brake ON state, the air pressure at the park brake valve control port (43) and on top of the spring-loaded relay piston (104) is exhausted through the park brake valve control port, the spring-loaded relay piston (104) then moves upward, thus opening the exhaust port and sealing the inlet, and air-from the delivery ports is then exhausted, thus applying parking brakes.
(vii) during anti-compounding braking, in case of absence of signal form hand brake valve at park brake valve control port (43) that is parking brake is already applied, when foot brake is operated, the air entering the service primary control port (41) acts over the check valve (127) which allows the higher air pressure and seals the passage against the park brake valve control port (43) and flows to the top of the spring-loaded relay piston (104), this air pressure forces the spring-loaded relay piston (104) to move downward against a compression spring (110) and contacts the bonded valve (111) . Further movement of the relay piston (104) opens the inlet passage thereby allowing air to flow from the reservoir port to the delivery ports (21-24), thus the parking brakes are released thereby preventing the compounding of the service brake and the parking brake and,
(viii) during primary service brake failure condition, in case of primary service signal failure at spring brake chambers control port (41) when the foot brake is depressed, the inversion relay valve (100) facilitates the air pressure at the secondary service control port (42) to trigger the inversion valve arrangement through a pilot operated balance valve piston (107) & breathing chamber (124) , this air pressure moves the balance valve piston downward against a spring and deflects a diaphragm (121) which contact with valve seat closes the exhaust path and flows into the inversion chamber (126), thus forces the inversion valve arrangement (105) to move downward further thereby exhausting air from the delivery ports (21-24) and applying the spring brakes, such that the air released from the spring brakes is proportional to the pressure at secondary service control port (42) thus providing the driver with a modulated application of the spring brakes.

2. The inversion relay valve (100) as claimed in claim 1, wherein the relay Piston (104) over the compression spring (110) and the inversion valve arrangement (105) comprises of a bonded valve (111), a compression spring (112) to provide sealing load, a spring guide (113), a retainer (114) with circlip (115) and sealing rings (116) (117) translate against the graduating spring (106) inside the valve body (101) to control the delivery air pressure according to air pressure in parking brake control chamber (118).

3. The inversion relay valve (100) as claimed in claim 1, wherein the balance valve piston (107) over the compression spring (119) with an adaptor (120) and a diaphragm (121) over the valve seat (122) with circlip (123) assembled in a breathing chamber (124) inside the valve body (101) which is connected by a cross-hole to balance chamber (125) and inversion chamber (126).

4. The inversion relay valve (100) as claimed in claim 1, the balance valve piston (107) translates against the compression spring (119) and allows the air from the secondary service brake control port (42) during the primary service brake control port (41) failure condition to the inversion chamber (126) through the breathing chamber (124) to translate the inversion valve arrangement (105) against graduating spring (106) and in turn to exhaust the delivery pressure.

5. The inversion relay valve (100) as claimed in claim 1, wherein the spring-loaded relay piston (1045) moves back and forth inside the valve body to control air pressure in the system.

6. The inversion relay valve (100) as claimed in claim 1, wherein the springs provide counteracting forces, assisting in the smooth operation of the pistons.

7. The inversion relay valve (100) as claimed in claim 1, wherein the inversion valve arrangement (105) moves back and forth inside the valve body to control air pressure in the system.

8. The inversion relay valve (100) as claimed in claim 1, the inversion valve arrangement (105) is connected to a balance valve piston (107) and quick release valve arrangement (124).

9. The inversion relay valve (100) as claimed in claim 1, the spring-loaded relay piston (104) and the inversion valve arrangement (105) which consists of the caged graduating spring (106) to provide the necessary load to achieve pressure limiting function.

10. A method of working of inversion relay valve (100) for air brake system as claimed in claim 1, said method comprises steps of:
a. during parking brake OFF state, the continuous air pressure from port 2 of graduated hand control valve (GHCV) at park brake valve control port (43) seals the check valve (127) against the passage of primary service control port (41) and flows into the cavity on control chamber (118) and this air-pressure forces the spring-loaded relay piston (104) to move downward against a compression spring (110) and contact the bonded valve (111) which further moves downward and contacts the exhaust port, and opens the inlet passage against a compression spring (112), thereby allowing air to flow from the reservoir port to the delivery ports, thus the parking brakes are released.
b. during parking brake ON state, the air pressure at the park brake valve control port (43) and on top of the spring-loaded relay piston (104) is exhausted through the park brake valve control port, the spring-loaded relay piston (104) then moves upward, thus opening the exhaust port and sealing the inlet, and air-from the delivery ports is then exhausted, thus applying parking brakes.
c. during anti-compounding braking, in case of absence of signal form hand brake valve at park brake valve control port (43) that is parking brake is already applied, when foot brake is operated, the air entering the service primary control port (41) acts over the check valve (127) which allows the higher air pressure and seals the passage against the park brake valve control port (43) and flows to the top of the spring-loaded relay piston (104), this air pressure forces the spring-loaded relay piston (104) to move downward against a compression spring (110) and contacts the bonded valve (111) . Further movement of the relay piston (104) opens the inlet passage thereby allowing air to flow from the reservoir port to the delivery ports (21-24), thus the parking brakes are released thereby preventing the compounding of the service brake and the parking brake and,
d. during primary service brake failure condition, in case of primary service signal failure at spring brake chambers control port (41) when the foot brake is depressed, the inversion relay valve (100) facilitates the air pressure at the secondary service control port (42) to trigger the inversion valve arrangement through a pilot operated balance valve piston (107) & breathing chamber (124) , this air pressure moves the balance valve piston downward against a spring and deflects a diaphragm (121) which contact with valve seat closes the exhaust path and flows into the inversion chamber (126), thus forces the inversion valve arrangement (105) to move downward further thereby exhausting air from the delivery ports (21-24) and applying the spring brakes, such that the air released from the spring brakes is proportional to the pressure at secondary service control port (42) thus providing the driver with a modulated application of the spring brakes.

-SD-
Dated this 23rd day of February 2024 Kalyanchand Jhabakh (IN/PA830)
Agent for applicant.