DESC:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
AND
The Patents Rules, 2003

COMPLETE SPECIFICATION
(Section 10 and Rule 13)

TITLE
A System to Protect Over-inflation of the Secondary Suspension

APPLICANT
(a) BEML LTD.
(b) An Indian Company,
(c) BEML Soudha,
No 23/1, IV Main, Sampangiramanagar,
Bengaluru, Karnataka, India

PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed.
FIELD OF THE INVENTION
This invention relates to a system to protect over-inflation of the secondary suspension. Particularly this invention relates to a system for use to protect overinflating of the secondary suspension used between the car body and bogie.
STATE OF THE ART IN THE FIELD
In the metro rail suspension system a secondary suspension, for example, an air spring is used between the car body and bogie. The air spring is some time over inflated due to the complex gradient, tighter curve negotiations and various dynamic conditions. In such cases, stiffness of secondary suspension is maintained by supplying more volume of air into air spring. Any error by user during the adjustment of the leveling rod may lead to over inflation and thus the air spring bursts.
There are disadvantages associated with the conventional system of metro rail suspension. One of the disadvantages is that there is no protection for over inflation of the secondary suspension.
Another disadvantage associated with the conventional system of metro rail suspension is that the air spring gets over inflated due to the complex gradient, tighter curve negotiations and various dynamic conditions.
Yet another disadvantage associated with the conventional system of metro rail suspension is that during the stiffness more volume of air is required into air spring.
Still another disadvantage associated with the conventional system of metro rail suspension is that an unintended error by the user during the adjustment of the leveling rod leads to over inflation causes the air spring to burst.
OBJECTS OF THE INVENTION
Therefore an object of the present invention is to provide a system to protect overinflating of the secondary suspension which obviates the disadvantages associated with conventional system of metro rail suspension.
Another object of the present invention is to provide a system which provides provisions against over inflation of the secondary suspension.
Yet another object of the present invention is to provide a system which increases the life of the secondary suspension.
Still another object of the present invention is to provide a system which doesn’t get stiff during sudden changes.
A further object of the present invention is to provide a system which provides limited supply of pressurized air to the secondary suspension / air spring.
Another object of the present invention is to provide a system which is not affected by user errors.
Yet another object of the present invention is to provide a system which doesn’t allow extra pressure in the air springs.
Still another object of the present invention is to provide a system which doesn’t allow air springs.
A further object of the present invention is to provide a system which makes sure that there are no accidents in air spring during maintenance.
SUMMARY OF THE INVENTION
According to this invention, there is provided a system to protect over-inflation of the secondary suspension comprising an air spring 4 adapted to be connected with a leveling valve 5 provided to maintain floor height, a differential valve unit 6 connected with reservoir 7 being provided to maintain the floor height, a reservoir 7 provide to supply air in the bellows 4 through the differential valve unit 6 and leveling valve 5, a pair of safety valve 8 is provided such that to protect over-inflation of the bellow 4 of the secondary suspension 3.
BRIEF DESCRIPTION OF THE DRAWINGS
A system to protect over-inflation of the secondary suspension according to a preferred embodiment of the present invention is herein described and illustrated in the accompanying drawings, wherein:
Figure 1, illustrates perspective view of a car with bogie,
Figure 2, illustrates plan view of the system of the present invention,
DETAILED DESCRIPTION OF THE INVENTION
A system to protect over-inflation of the secondary suspension is herein described with numerous specific details so as to provide a complete understanding of the invention. However, these specific details are exemplary details and should not be treated as the limitation to the scope of the invention. Throughout this specification the word “comprise” or variations such as “comprises or comprising”, will be understood to imply the inclusions of a stated element, integer or step, or group of elements, integers or steps, but not the exclusions of any other element, integer or step or group of elements, integers or steps.
Referring to the drawings, particularly figures 1, a car 1 of a rolling stock (not shown) is supported on a pair of bogies 2 provided near front end and rear end of the car 1. A secondary suspension system 3 is provided between the lower surfaces of the car 1 and upper surface of the bogy 2. The secondary suspension system 3 is provided with each pair of bogies 2 so as to provide ride quality to the passengers.
Referring to figure 2, a system to protect overinflating of the secondary suspension is shown. Each secondary suspension system 3 comprises an air spring / bellow 4, adapted to be connected with a leveling valve 5 in flow communication. The leveling valve 5 is provided to maintain floor height i.e. when weight is increased air id filled into the bellow 4 and when the weight is decreased the air is expelled out from the bellow 4 through a vent so as to maintain the floor height all the time. A differential valve unit 6, having plurality of valves 7 connected with each other, is provided to maintain the floor height, by bleeding the air from the healthy bellow 4, in the event of any of the bellow 4 is blasted due to any reason, for example, shelf life or over-inflation. A reservoir 7 is provided to supply air in the bellows 4 through the differential valve unit 6 and leveling valve 5. Similarly, an air spring / bellow 4, adapted to be connected with a leveling valve 5 in flow communication therewith is provided on the other side of the differential valve unit 6.
Specifically, according to the present invention a pair of safety valve 8 is provided between the air spring / bellow 4 and levelling valve 5 on either sides of the differential valve unit 6 to protect over-inflation of the bellow 4 of the secondary suspension 3. The safety valve 8 comprises spring actuated safety valve, set to required pressure so as to release the air if the set pressure is reached and will stop acting as soon as the required pressure is reached. The safety valve 8 acts when car 1 is negotiating a tight curve with full passenger load. In such a situation weight, on the bellow 4 provided on one side, i. e. inner radius side, is increases for time being and the leveling valve 5 start filling the air into that bellow 4 so as to change its characteristic in order to maintain floor height. The safety valve 8 in such a situation avoids the change in the stiffness and over-inflation of air spring / bellow 4.
Certain features of the invention have been described with reference to the exemplary embodiments. However, the description is not intended to be construed in a limiting sense. Various modifications of the exemplary embodiments as well as other embodiments of the invention, which are apparent to the persons skilled in the art to which the invention pertains, are deemed to lie within the spirit and scope of the invention. ,CLAIMS:WE CLAIM:
1. A system to protect over-inflation of the secondary suspension comprising an air spring 4 adapted to be connected with a leveling valve 5 provided to maintain floor height, a differential valve unit 6 connected with reservoir 7 being provided to maintain the floor height, a reservoir 7 provide to supply air in the bellows 4 through the differential valve unit 6 and leveling valve 5, a pair of safety valve 8 being provided such that to protect over-inflation of the bellow 4 of the secondary suspension 3.
2. The system to protect over-inflation of the secondary suspension as claimed in claim 1, wherein the air spring comprises a bellow.
3. The system to protect over-inflation of the secondary suspension as claimed in claim 1, wherein the differential valve comprises plurality of valves connected with each other.
4. The system to protect over-inflation of the secondary suspension as claimed in claim 1, wherein safety valve being provided between the air spring and a levelling valve on either sides of the differential valve unit.
5. The system to protect over-inflation of the secondary suspension as claimed in claim 1, wherein safety valve comprises a spring actuated safety valve.
6. The system to protect over-inflation of the secondary suspension as claimed in claim 1, wherein safety valve is set to the required pressure such that to release air when pressure reached to the set required pressure .
Dated this 12th day of February, 2020

R. P. Yadav
of sr4ipr Partners
Applicant’s Attorney