Field of Invention
The present invention generally relates an air spring failure indication and brake application device (ASFIBAD) and more particularly, relates to an air spring failure indication and brake application device (ASFIBAD) comprising of three resetting keys integrated with three non-return valves and a method of its operation.

Background of the invention
Air spring failure is usually caused by abrasion or short cracks in the rubber or ballast accelerated with an unusually high intensity.
Various types of coaches like BGICF, LHB, Hybrid, Double Decker main line coaches having ICF and LHB type Bogies on Indian Railways are fitted with air springs to absorb the shocks and jerk. It has become a need of the Indian Railways to use a mechanism which can detect and apply the brakes in the train in case of any air spring failure, and make the detection process effective through which there are less accidents and safety of passenger’s increases. In the current invention, the method used for operation of air spring indication failure and brake application device overcomes the problem of detection of such failure at that particular time.

Objectives of the Invention
The prime objective of the present invention is to provide a method for operation of air spring failure indication and brake application device, comprises of three resetting keys, three non-return valves, three normally closed valves, two absolute modules and two indicators.

Another objective of the present invention is to provide a method for operation of air spring failure indication and brake application device where the resetting keys are mounted on non-return valves.

Yet another objective of the present invention is to provide a method for operation of air spring failure indication and brake application device where normally closed valves are spring loaded valves and actuates when air spring pressure is supplied to the normally closed valve in the form of pilot pressure.

Yet another objective of the present invention is to provide a method for operation of air spring failure indication and brake application device where normally-return valve allows air to flow in only one direction.

It is an objective of the present invention where three non-return valves are fitted in a manner that, it ensures the air flows in the right direction, where pressure conditions may otherwise cause reversed flow.

Another objective of the present invention is to provide a method for operation of air spring failure indication and brake application device where two absolute pressure modules comprises of a valve to sense the pressure of compressed air in each bellow of the bogie constantly and initiate normal brake application when the pressure in anyor both air spring bellows of concerned bogie drops to 1±0.1 Kg/Sq.cm.

Still yet another objective of the present invention is to provide a method for operation of air spring failure indication and brake application device having various advantages that comprises of easy handling, light in weight, compact size, less maintenance and more reliable due to less no. of parts.

These and other objectives of the present invention will be apparent from the drawings and descriptions herein. Every object of the invention is attained by at least one embodiment of the invention. However, no embodiment necessarily meets every object set forth herein.

Brief Description of Drawings
The invention will now be described with reference to the accompanying drawing, in which:
Figure 1 is circuit diagram of the air spring failure indication and brake application device (ASFIBAD).
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
Detailed description of the invention with the accompanying drawings
The following is a detailed description of exemplary embodiments to illustrate the principles of the invention. The embodiments are provided to illustrate aspects of the invention, but the invention is not limited to any embodiment. The scope of the invention encompasses numerous alternatives, modifications and equivalent; it is limited only by the claims.

The illustrative and preferred embodiments in accordance with the present invention will now be described with reference to the accompanying drawings.

The present invention relates to a pneumatically controlled system which acts as a safety device to meet the requirement of a full proof arrangement of Air Spring Suspension system for passenger coaches.

Generally the invention disclosed herein pertains to a method for operation of air spring failure indication and brake application device (herein after referred as ‘ASFIBAD’), comprises of three resetting keys integrated with three non-return valves, three normally closed valves, two absolute modules and two indicators.

One of the preferred embodiments of the present invention is an air spring failure indication and brake application device comprising of three resetting keys (1, 2, 3), three non-return valves (4, 5, 6), three normally closed valves (7, 8, 9), two absolute pressure modules (10, 11) and two indicators (12, 13) and the device works at air spring pressure within range of 2 kg/cm2 to 6 kg/cm2 and at brake pipe pressure of 5 kg/cm2.
Another embodiment of the present invention is a method of operation of the air spring failure indication and brake application device wherein the steps of operation comprises the steps as follows:-
- initially charge the device with a brake pipe pressure of 5 ±0.1 Kg/cm2 through Brake pipe port (BP) and air spring pressure 6±0.1 Kg/cm2 through two ports (B1, B2) in following steps:
(a) The Brake pipe pressure go to the normally closed valve (7, 8 and 9);
(b) the air spring pressure go to the absolute pressure module (10 , 11), then to the non-return valve (4,6), then to the resetting key (1,2)and finally to the normally closed valve (7,9);
(c) for the normally closed valve (7, 9),the air spring pressure will act as a pilot pressure and will open the normally closed valve (7, 9)at a pressure of minimum 1.6kg/cm2 allowing the flow of pressure finally to the absolute pressure module (10,11) and then charging of the device gets completed.
- if air spring failure takes place then air spring pressure starts reducing.
- When the air spring pressure reaches 1±0.1 Kg/cm2, the absolute pressure module (10 or 11)of the device valve gets actuated air flows to the non-return valve (5), the resetting key (3), the indicator (12, 13)and the normally closed valve (8)and the air spring pressure at 1±0.1 Kg/cm2 acts as a pilot pressure and actuates the normally closed valve (8);
- due to actuation of the normally closed valve (8),brake Pipe start venting from exhaust port provided on the device manifold and settles at 3.4 Kg/cm2 approx;
- simultaneously the indicator (12, 13) turns red from green;
- once the device is actuated the brake pipe pressure will keep venting until some manual intervention is done;
- to reset the device to its initial position the train crew has to manually pull the resetting key (1), then the resetting key (2) and finally the resetting key (3) for 2 seconds approx. each in sequence;
- once there setting keys (1, 2, 3) are pulled, brake pipe pressure exhaust port (BP) is closed and when Brake Pipe pressure rises to 5±0.1 Kg/cm2 again, the indicators (12, 13) turns green;
- similar sequential operations are followed for actuation of the device up to minimum pressure of 2±0.1kg/cm2 and Brake Pipe Pressure of 5±0.1 kg/cm2.
Referring to the figure 1, it is depicted that the three “resetting keys (1, 2, 3) are mounted on the non-return valves (4, 5, 6). When the device gets actuated, there setting keys (1, 2, 3) are pulled in the sequence mentioned above to reset the device valve to its initial position. The normally closed valves (7, 8, 9) are spring loaded valves and get actuates when air spring pressure is supplied to the normally closed valves (7, 8, 9) in the form of pilot pressure. The non-return valve (4, 5, 6) allows air to flow in only one direction. The three non-return valve (4, 5, 6) are fitted to ensure that the airflows in the right direction, where pressure conditions may otherwise cause reversed flow. The absolute pressure module (10, 11) consists of a valve to sense the pressure of compressed air in each bellow of the bogie constantly and initiate normal brake application when the pressure in any or both air spring bellows of concerned bogie drops to 1±0.1Kg/Sq.cm.
An indicator 12 and 13 denotes the failure of air spring, where, green color indicator denotes normal air spring and red color indicator denotes failure of air spring.

The basic application of ASFIBAD is to actuate the brakes in the event of air spring failure. This will immediately reduce the speed of the train and ultimately bring the train to a standstill position. The indicator of the respective failed air spring will turn to red. A hissing sound will occur to indicate the location of air spring that has failed. The train is then checked by the engine crew and after taking necessary action, train is allowed to move at a prescribed speed in the event of failure of the air spring.

The advantages of the present invention comprises of easy handling, light in weight, compact size, less maintenance and more reliable due to less number of parts.
Although preferred embodiments of the invention has been illustrated and described, it will at once be apparent to those skilled in the art that the invention includes advantages and features over and beyond the specific illustrated construction. Accordingly it is intended that the scope of the invention be limited solely by the scope of the hereinafter appended claims, and not by the foregoing specification, when interpreted in light of the relevant prior art.

CLAIMS:
1. An air spring failure indication and brake application device comprises of:
three resetting keys (1, 2, 3);
three non-return valves (4, 5, 6);
three normally closed valves (7, 8, 9);
two absolute pressure modules (10, 11); and
two indicators (12, 13);
wherein the resetting keys (1, 2, 3) are mounted on the non-return valves (4, 5, 6) get pulled to reset a device valve to its initial valve after the device actuation, the normally closed valves (7, 8, 9) actuates when air spring pressure is supplied to the normally closed valves (7, 8, 9), the non-return valves (4, 5, 6) allow air to flow in one direction, the absolute pressure module (10, 11) consists of a valve to sense the pressure of compressed air in each bellow of a bogie constantly and indicator (12, 13) denotes the failure of air spring.

2. An air spring failure indication and brake application device as claimed in claim 1, wherein the method of operation of the device comprises the steps of:
- charging the device with a brake pipe pressure of 5 ±0.1 Kg/cm2 through Brake pipe port (BP) and air spring pressure 6±0.1 Kg/cm2 through two ports (B1, B2), following the steps of:
(d) the Brake pipe pressure flows to the normally closed valve (7, 8 ,9);
(e) the air spring pressure flows to the to the normally closed valve (7,9) via absolute pressure module (10 , 11), the non-return valve (4,6), and the resetting key (1,2);
(f) the air spring pressure open the normally closed valve (7, 9) at a pressure of minimum 1.6kg/cm2 allowing the flow of pressure to the absolute pressure module (10,11);
- when air spring failure takes place, the air spring pressure starts reducing such that the when the pressure reaches 1±0.1 Kg/cm2, the absolute pressure module (10,11) of the device valve gets actuated and air flows to the non-return valve (5), the resetting key (3), the indicator (12, 13) and the normally closed valve (8) is actuated at the air spring pressure at 1±0.1 Kg/cm2;
- brake pipe start venting from exhaust port provided on the device manifold and settles at 3.4 Kg/cm2approx;
- simultaneously the indicator (12, 13) turns red from green;
- once the device is actuated the brake pipe pressure will keep venting until some manual intervention is done;
- resetting the device to its initial position, the resetting key (1), the resetting key (2) and finally the resetting key (3) are manually pulled in sequence;
- once the resetting keys (1, 2, 3) are pulled, brake pipe pressure exhaust port (BP) is closed and when Brake Pipe pressure rises to 5±0.1 Kg/cm2 again, the indicators (12, 13) turns green;
- similar sequential operations are followed for actuation of the device up to minimum pressure of 2±0.1kg/cm2 and Brake Pipe Pressure of 5±0.1 kg/cm2.

3. An air spring failure indication and brake application device as claimed in claim 1, wherein said device works at air spring pressure of range 2kg/cm2 to 6 Kg/cm2 and at the brake pipe pressure is5Kg/cm2.

4. An air spring failure indication and brake application device as claimed in claim 1, wherein said the resetting key (1), the resetting key (2) and finally the resetting key (3) are manually pulled in sequence to reset said device to its initial position, after actuation.

5. An air spring failure indication and brake application device as claimed in claim 1, wherein the normally closed valves (7, 8, 9) are spring loaded valves.

6. An air spring failure indication and brake application device as claimed in claim 1, wherein the non-return valve (4, 5, 6) are fitted to ensure that the air flows in the right direction, where pressure conditions get reversed flow.

7. An air spring failure indication and brake application device as claimed in claim 1, wherein the absolute pressure module (10, 11) sense the pressure of compressed air in each bellow of the bogie constantly and initiate normal brake application when the pressure in any air spring bellows of concerned bogie drops to 1±0.1Kg/cm2.