Title of Invention

INVERSION RELAY VALVE FOR AIR BRAKE SYSTEM OF A MOTOR VEHICLE

Abstract 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 primĀ»-y piston and 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 moveable, independently of the relay piston, between a first stop on the valve body and a second stop on the relay piston.
Full Text

This invention relates to an inversion relay valve for the air brake system of a motor vehicle, which is the subject matter of our Application for Patent under Serial No. 857 /MAS/2001 hereinafter called our earlier invention.
In our earlier invention, any air pressure at the primary service port acts upon the primary piston, after die air passes through a cross hole, and also directly upon the relay piston. To avoid the latter condition, which is unnecessary, this invention proposes a spring-loaded ring piston, surrounding the relay piston. The ring piston takes up such air pressure on itself, without permitting it to act on the relay piston directly.
So also whenever any small pressure differeotial, or a fluctuatmg pressure differential, between the air pressure at the secondary service port and a lower air pressure at the primary service port exits, this is taken up by the spring-loaded ring piston and not by the relay piston thereby avoiding unnecessary actuation of the relay piston.
The inversion relay valve for the air brake system of a motor vehicle, according to this invention, comprises 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 relay piston; a diaphragm valve lor the spring brake control port and an air chamber provided above the primary piston ; a spring-loaded inlet/exhaust valve, characterised by a spring-loaded ring piston surrounding the relay piston, said ring piston being located in the annular space provided in the valve body adjacent the relay piston, and moveable, independently of the relay piston, between a first stop on the valve body and a second stop on the relay piston, whereby air pressure at the primary service port is taken up by the spring-loaded rmg piston moving downwards against spring force, and not by the relay piston; air pressure at the secondary service port is initially taken up by the ring piston moving upwards against spring force until contact takes place between the ring piston and the second stop to move the relay piston also upwards; and pressure differential between the air pressure at the secondary service port and a lower air pressure at the primary service port, is taken up by the ring piston moving upwards against spring force and not by the relay piston.
This invention will now be described with reference to the
accompanying drawings which illustrate
In Fig.l a view of an embodiment of the inversion valve
according to our present invention
In Fig.lA a corresponding view of an embodiment of the
inversion valve according to our earlier invention

in Fig.2 another view of an embodiment of the inversion valve according to our present invention
In Fig.2A a corresponding view of an embodiment of the inversion valve accordmg to our earlier invention
In Fig.3 yet another view of an embodiment of the inversion valve according to our present mvention In Fig.3A a corresponding view of an embodiment of the inversion valve according to our earlier invention
The inversion valve for the air brake system of a motor vehicle, according to this invention, comprises a valve body 1 provided with a spring brake control port A, a primary service port PlĀ» a secondary service port P2, a reservour port B, a delivery port C and an exhaust port D.
The valve body houses a spring-loaded primary piston 3 and relay piston 5. A diaphragm valve 2 is provided for the spring brake control port A . E is an air chamber above the primary piston 3. A spring-loaded in let/exhaust valve is indicated by 6.
The foregoing components are all comprised m the inversion valve according to our earlier invention and reference may be made to the Complete Specification for the description of the

nature of such iuveution and the manner in which it is performed.
Our present invention is substantially similar to our earlier invention but is characterised by a spring-loaded ring piston, the ring piston bemg indicated by 7 and the spring being indicated by 8.
The ring piston surrounds the relay piston S and is located in the space S provided in the valve body 1 adjacent the relay piston S. The ring piston is moveable in the space S between a first stop T on the valve body and a second stop R on the relay piston 5. The stop R thus moves with the relay piston 5. The ring piston 7 moves independently of the relay piston.
From the foregoing construction, it will be observed that
(i) whenever air pressure is present at the prim ary service port PI it is taken up by the spring-loaded ring piston, and not by the relay piston, the ring piston moving downwards while taking up such pressure (see Fig. 1 contra Fig.lA)
(ii) whenever air pressure exists at the secondary service port P2 it is initially taken up by the rmg piston 7, to move it upwards until contact takes place between the ring piston 7 and the second stop R to move the relay piston 5 also upwards (see Fig.2 contra Fig.2A)

(iii) any pressure differential between the air pressure at the secondary service port F2 and a lower air pressure at the primary service port PI, is taken up by the spring-loaded ring piston 7 and not by the relay piston 5 (see Fig.3 contra Fig.3A).
The provision of the spring-loaded piston 7 renders the inversion valve according to the present invention more stable than the inversion valve accordmg to our earlier mvention, since the relay valve does not unnecessarily expose itself to air pressures affecting its performance.
The terms and expressions in this specification are of description and not of limitation, inasmuch as other embodiments of the inversion valve proposed herein are possible without departing from the scope and ambit of this invention.



We Claim:
l. 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 relay piston; a diaphragm valve for the spring brake control port and an air chamber provided above the primary piston ; a spring-loaded inlet/exhaust valve, characterised by a spring-loaded ring piston surrounding the relay piston, said ring piston being located in a an annular space provided in the valve body adjacent the relay piston, and moveable, independently of the relay piston, between a first stop on the valve body and a second stop on the relay piston, whereby air pressure at the primary service port is taken up by the sprmg-loaded ring piston moving downwards against spring force, and not by the relay piston; air pressure at the secondary service port is initially taken up by the ring piston moving upwards against spring force until contact takes place between the ring piston and the second stop to move the relay piston also upwards; and pressure differential between the air pressure at the secondary service port and a lower air pressure at the primary service port, is taken up by the ring piston moving upwards against spring force and not by the relay piston.

2.An inversion relay vaive as claimed in Claim 1 wherein one end of the spring of the ring piston is fixed to the valve body and the other end to the ring piston itself.
3. An inversion relay valve as claimed in Claim I or Claim 2 wherein the spring of the ring piston exerts compressive and tensile forces, respectively, during the upward and downward movement of the ring piston.
4.An inversion relay valve for the air brake system of a motor vehicle substantially as herein described and illustrated with reference to Figs. 1,2 and 3 of the accompanying drawings.


Documents:

537-che-2003-abstract.pdf

537-che-2003-claims duplicate.pdf

537-che-2003-claims original.pdf

537-che-2003-correspondnece-others.pdf

537-che-2003-correspondnece-po.pdf

537-che-2003-description(complete) duplicate.pdf

537-che-2003-description(complete) original.pdf

537-che-2003-drawings.pdf

537-che-2003-form 1.pdf

537-che-2003-form 19.pdf

537-che-2003-form 26.pdf


Patent Number 198858
Indian Patent Application Number 537/CHE/2003
PG Journal Number 08/2007
Publication Date 23-Feb-2007
Grant Date 21-Feb-2006
Date of Filing 30-Jun-2003
Name of Patentee M/S. SUNDARAM CLAYTON LIMITED
Applicant Address JAYALAKSHMI ESTATES, NO.8 HADDOWS ROAD, CHENNAI 600 006
Inventors:
# Inventor's Name Inventor's Address
1 SUNDARAMAHLINGAM SELVAMANI JAYALAKSHMI ESTATES, NO.8 HADDOWS ROAD, CHENNAI 600 006
PCT International Classification Number B6OT15/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA