The invention relates to a Bogie Mounted Brake Cylinder (herein after referred as BMBC), to be used in high speed passenger coaches of railway trains, and the method of its functioning thereof, wherein said BMBC is mainly characterized in being Double Acting Brake Cylinder with integral Double Acting Slack Adjuster and the functioning of the assembly of said Bogie Mounted Brake Cylinder during Brake application as well as Brake release, as depicted and illustrated in Figures 1 and 2 herein below. Said BMBC is uniquely designed, comprising lesser number of components and sub-assemblies thereof, wherein it has minimum wear, tear and maintenance requirement. It also provides a trouble-free operation, particularly under the Indian Railway operating conditions.

BACKGROUND AND PRIOR ARTS:
Brake Cylinders are conventionally used in the Braking system of vehicles, particularly in Railway Coaches. At present in India, the Mainline conventional coaches of Integral Coach Factory are using BMBC with Single Acting Slack Adjuster. Railways have reported that the Piston stroke maximum on ICF Coaches gets reduced up to 20 mm from the pre-set value of 32 mm in every trip. Due to which, Manual re-adjustment of Piston stroke in each trip becomes necessary.
Sometimes, frequent brake binding on General (GS) and Sleeper and Luggage Rack (SLR) coaches is also reported in Brake Cylinder having Single Acting Slack Adjuster, which allows the piston rod to pay-out in loaded condition and is not allowed to go back due to absence of pay-in mechanism when the coach becomes empty. This problem mostly occurs in GS and SLR coaches due to loading pattern of these coaches, causing huge variation in tare and loaded weight is observed. This is the primary reason for the need of Double Acting Slack Adjuster in Bogie Mounted Brake Cylinder used for BG main line coaches.

Object of the invention:
Prime object of the instant invention is to provide a Bogie Mounted Brake Cylinder (BMBC), to be used in high speed passenger coaches of railway trains, and the method of its functioning thereof, wherein said BMBC is mainly characterized in its Double Acting Brake Cylinder with integral Double Acting Slack Adjuster and the functioning of the whole assembly of said Bogie Mounted Brake Cylinder during Brake application as well as Brake release, as depicted and illustrated in Figures 1 and 2 herein below.
Another object of the present invention is to provide a Bogie Mounted Brake Cylinder (BMBC), which is characterized in the following advantageous structural/functional features:
a) Brake Cylinder with integral Double Acting Slack Adjuster;
b) No change required in existing mounting of Cylinder [Replaceable] ;
c) Automatically maintains a constant Piston stroke. There is no need to adjust the Brake Cylinder stroke intermittently, whenever there is a change in the clearance between the Wheel and Brake Blocks;
d) User friendly, no need to adjust the Piston stroke during replacement of Brake Block;
e) Economical;
f) Lighter in weight;
g) Easy to handle;
h) Compact in size;
i) More reliable.
Another object of the present invention is to provide a Bogie Mounted Brake Cylinder (BMBC), wherein:
• The Bogie Mounted Brake Cylinder Unit design is unique;
• Unique mechanism of Brake Cylinder with in-built Double Acting Slack Adjuster;
• Slack Adjuster maintains the required clearance in both the conditions i.e. if the clearance is more or if the clearance is less between the Wheels and Brake Shoe.
Another object of the present invention is to provide a Bogie Mounted Brake Cylinder (BMBC), wherein:-
• The basic working principle of Bogie Mounted Brake Cylinder is that the pressurized air goes into the Cylinder Body (1) and pushes the Piston Assembly (4) forward against the Return Spring (7) and Spindle Spring (6).
• Such pressurization of Piston Assembly (4) causes the Spindle Tube Assembly (8) to move forward till the Brake Shoe touches the Wheel, applying the Brake force on the Wheel.
• The Piston Screw on the Piston Assembly (4) remains engaged with the Spindle Gear on the Spindle Assembly and thus, there is no extension of the Spindle Tube Assembly (8) on the Spindle Assembly (When no Slack Adjustment is required).
• The internal construction (Clearance between Piston Assembly (4) and Cylinder Front Cover (2)) ensures that the Piston stroke of the Brake Cylinder is constant when no Slack Adjustment is required.
• When the Brake Shoes and/or the Wheel has worn out, then the clearance between the Wheel and the Brake Shoe would be increased.
• Now when the air goes into the Cylinder Body (1), the Piston Assembly (4) moves forward. It moves the Spindle Tube Assembly (8) beyond the control distance as there is a slack (there is no restraint to the Spindle Tube Assembly (8) extension).
• As the Spindle Tube Assembly (8) travels more than normal stroke, the Spindle Spring (6) pushes the Spindle Assembly and slack becomes operational to cover up the clearance.
Another object of the present invention is to provide a Bogie Mounted Brake Cylinder (BMBC), wherein the method of functioning of said BMBC involves characteristic steps/features during its Brake application, as under:-
During the Brake Application, the input air pressure enters the Cylinder Body (1). This pressure acts on the Piston Assembly (4). Due to this pressure, the Piston Assembly (4) inside the Cylinder Body (1) moves in forward direction against the force of Return Spring (7) fitted inside the Cylinder Body (1). A Threaded Spindle is fitted inside the Piston Assembly (4) with the help of four Screws. The forward movement of Piston Assembly (4) moves the Spindle Tube Assy. (8) along with it, which in turn, pushes the Brake Shoe and Applies Brake, retarding the Wheel Movement.
Another object of the present invention is to provide Bogie Mounted Brake Cylinder (BMBC), wherein the method of functioning of said BMBC involves characteristic steps/features during forward and backward slack movement/position thereof, as under:-
Forward Slack: -
During repeated Brake Application, due to the rubbing of the Brake Shoe and Wheel the clearance is increased. When the clearance between the Brake Shoe and the Wheel is more than normal, then Piston Assembly (4) moves further making the Spindle Spring compress against the bearings, which is press fitted on to the Spindle Assembly. This releases the Spindle Assembly Gears inside the Piston, making it free to rotate. Now the Slack Tube Spring (9) pushes the Spindle Tube Assembly (8) outwards due to spinning movement of the Spindle Tube Assembly (8). The Spindle Tube Assembly (8) comes outwards till it touches the Wheel. Likewise the slack takes place in the outwards direction (Pay-out).
Backward Slack: -
If the clearance between the Wheel and the Brake Shoe is lesser than normal, then Spindle Tube Assembly (8) exerts force, generated by Piston in opposite direction. This will dis-engage the Spindle Gears from Piston Assembly (4) and the Spindle Assembly rotates until it touches the other side of the gears present in the Piston. In this position, the Spindle Tube Assembly collapses inwards thus creating required clearance between the Wheel and Brake Shoe as soon as the brakes are released. This is how the slack takes place in the inward direction (Pay-in).
Another object of the Present invention is to provide a Bogie Mounted Brake Cylinder (BMBC), wherein the method of functioning of said BMBC involves characteristic steps/features during its Brake Release, as under: -
Brake release: - During the release of the brake, the input pressure to the Brake Cylinder gets exhausted due to which the Return Spring moves the Piston Assembly (4) back. Along with the Piston Assembly (4), Slack Tube Assembly (8) moves back to its initial position in turn, automatically Maintaining the required clearance.
Another object of the present invention is to provide a Bogie Mounted Brake Cylinder (BMBC), particularly characterized in its structural, constructional and functional features, ensuring a safe and comfortable journey to the passengers, travelling in railway trains.
SHORT DETAILS OF THE DRAWINGS:
Schematic drawings referred herein for describing and illustrating the instant invention, are mentioned herein as under:
Figure 1: Complete Isometric side view of the BOGIE MOUNTED BRAKE CYLINDER;
Figure 2: Represents the schematic cross-sectional view of the BRAKE CYLINDER as disclosed herein, showing its all major components and their assembly and sub-assemblies.
An Index of the numeric references, employed in the illustrative drawing of Figure 2 herein is as under:

Number representing structural/constructional feature of the (BMBC), as depicted in drawings Description Quantity
1 CYLINDER BODY 8" 1
2 CYLINDER FRONT COVER 1
3 GASKET 1
4 PISTON ASSY. 1
5 SUPPORT BUSH 1
6 SPINDLE SPRING 1
7 RETURN SPRING 1
8 SPINDLE TUBE ASSY. 1
9 SLACK TUBE SPRING 1
10 WIPER SEAL 1
11 TEE HEAD BOLT M12 4
12 HEX NUT M12 4
13 SPRING WASHER B12 4
14 BUSH 1

DESCRIPTION OF THE PRESENT INVENTION:
The present invention in general relates to the bogie mounted brake cylinder to be used in high speed passenger coaches of railway train.
As per the conventional practice in Indian Railways, the main line conventional coaches of Integral Coach Factory are using BMBC with Single Acting Slack Adjuster. Railways have reported that the Piston stroke of 203 mm size BMBC on ICF coaches gets reduced up to 20 mm from the pre-set value of 32 mm in every trip. Due to which, Manual re-adjustment of Piston stroke in each trip becomes necessary. Sometimes, frequent brake binding on GS and SLR coaches is also reported in Single Acting Slack Adjuster, which allows the piston rod to pay-out in loaded condition and is not allowed to go back due to absence of pay-in mechanism when the coach becomes empty. This problem is limited to GS and SLR coaches due to dense loading in these coaches, therefore, huge variation in tare and loaded weight is observed. This is the primary reason for the need of Double Acting Slack Adjuster in Bogie Mounted Brake Cylinder used for BG main line coaches.
BMBC is a Pneumatically Controlled System which acts as a braking device to meet the requirement of Braking and Automatic Slack Adjustment, in Railway Coaches. It pertains to a unique design of Bogie Mounted Brake Cylinder containing lesser number of Parts /Sub-Assemblies. The Double Acting Brake Cylinder is designed such that it has minimum wear, tear and maintenance requirement. It also provides a trouble free operation under the Indian Railways operating conditions.

WORKING PRINCIPLE FOR BOGIE MOUNTED BRAKE CYLINDER (BMBC)
The basic working principle of Bogie Mounted Brake Cylinder is that the pressurized air goes into the Cylinder Body (1) and pushes the Piston Assembly (4) forward against the Return Spring (7) and Spindle Spring (6). This causes the Spindle Tube Assembly (8) to move forward till the Brake Shoe touches the wheel, applying the Brake force on the wheel. The Piston Screw on the Piston Assembly (4) remains engaged with the Spindle Gear on the Spindle Assembly. Thus, there is no extension of the Spindle Tube Assembly (8) on the Spindle Assembly. The internal construction (Clearance between Piston Assembly (4) and Cylinder Front Cover (2)) ensures that the stroke of the Brake Cylinder is constant when no Slack Adjustment is required.
When the Brake Shoes and/or the Wheel has worn out, then the clearance between the Wheel and the Brake Shoe would be increased. Now, when the air goes into the Cylinder Body (1), the Spindle Tube Assembly (8) moves forward. It moves beyond the control distance as there is a slack (there is no restraint to the Spindle Tube Assembly (8) extension).
As the Spindle Tube Assembly (8) travels more than normal stroke, the Spindle Spring (6) pushes the Spindle Assembly and slack becomes operational to cover up the clearance.
Brake application: - During the Brake Application, the input air pressure enters the Cylinder Body (1). This pressure acts on the Piston Assembly (4). Due to this pressure, the Piston Assembly (4) inside the Cylinder Body (1) moves in forward direction against the force of Return Spring (7) fitted inside the Cylinder Body (1). A Threaded Spindle is fitted inside the Piston Assembly (4).
The forward movement of Piston Assembly (4) moves the Spindle Tube Assy. (8) along with it, which in turn, pushes the Brake Shoe and Applies Brake, retarding the Wheel Movement.
Forward Slack: -
During repeated Brake Application, due to the rubbing of the Brake Shoe and Wheel the clearance is increased. When the clearance between the Brake Shoe and the Wheel is more than normal, then Piston Assembly (4) moves further making the Spindle Spring compress against the bearings, which is press fitted on to the Spindle Assembly. This releases the Spindle Assembly Gears inside the Piston, making it free to rotate. Now the Slack Tube Spring (9) pushes the Spindle Tube Assembly (8) outwards due to spinning movement of the Spindle Tube Assembly (8).
The Spindle Tube Assembly (8) comes outwards till it touches the Wheel. Likewise the slack takes place in the outwards direction (Pay-out).
Backward Slack: -
If the clearance between the Wheel and the Brake Shoe is lesser than normal, then Spindle Tube Assembly (8) exerts force, generated by Piston in opposite direction. This will dis-engage the Spindle Gears from Piston Assembly (4) and the Spindle Assembly rotates until it touches the other side of the gears present in the Piston. In this position, the Spindle Tube Assembly collapses inwards thus creating required clearance between the Wheel and Brake Shoe. This is how the slack takes place in the inward direction (Pay-in).
Brake release: - During the release of the brake, the input pressure to the Brake Cylinder gets exhausted due to which the Return Spring moves the Piston Assembly (4) back. Along with the Piston Assembly (4), Slack Tube Assembly (8) moves back to its initial position in turn, automatically maintaining the clearance.

ADVANTAGES OF INSTANT BOGIE MOUNTED BRAKE CYLINDER (BMBC)
1. Brake Cylinder with integral Double Acting Slack Adjuster;
2. No change required in existing system [Replaceable] ;
3. Automatically maintains a constant Piston stroke. No need to adjust the Brake Cylinder stroke intermittently, whenever there is change in the clearance between the Wheel and Brake Blocks;
4. User friendly, no need to adjust the Piston stroke during replacement of Brake Block;
5. Economical;
6. Lighter in weight;
7. Easy to handle;
8. Compact in size;
9. More reliable.

Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternate embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It is therefore contemplated that such modifications can be made without departing from the spirit or scope of the present invention as defined.

CLAIMS:WE CLAIM
1. Bogie Mounted Brake Cylinder (BMBC) and the method of its functioning thereof, wherein preferred embodiment of the said BMBC comprises cylinder body (1), cylinder front cover (2), gasket (3), piston assembly (4), support bush (5), spindle spring (6), return spring (7), spindle tube assembly (8), slack tube spring (9), wiper seal (10), tee head bolt M12, HEX nut M12, spring washer B12 and bush (14), wherein said assembly of (BMBC) is mainly characterized in its Double Acting Brake Cylinder with integral Double Acting Slack Adjuster and the functioning of the whole assembly of said Bogie Mounted Brake Cylinder during Brake application as well as Brake release; and wherein the method of functioning of said BMBC is characterized in the characteristic steps/features during forward and backward slack movement/position thereof as well as in the characteristic steps/features during its Brake Release
2. Bogie Mounted Brake Cylinder (BMBC) and the method of its functioning thereof, as claimed in claim 1, wherein said Bogie Mounted Brake Cylinder (BMBC) is characterized in the following advantageous structural/functional features:
a. Brake Cylinder with integral Double Acting Slack Adjuster;
b. No change required in existing system [Replaceable];
c. Automatically maintains a constant Piston stroke. No need to adjust the Brake Cylinder stroke intermittently, whenever there is change in the clearance between the Wheel and Brake Blocks;
d. User friendly, no need to adjust the Piston stroke during replacement of Brake Block;
e. Economical;
f. Lighter in weight;
g. Easy to handle;
h. Compact in size;
i. More reliable.
3. Bogie Mounted Brake Cylinder (BMBC) and the method of its functioning thereof, as claimed in claim 1, wherein :
• The Bogie Mounted Brake Cylinder Unit design is unique;
• Unique mechanism of Double Acting Brake Cylinder with in-built Slack Adjuster;
• Slack Adjuster maintains the required clearance in both the conditions i.e. if the clearance is more or if the clearance is less between the Wheels and Brake Shoe.
4. Bogie Mounted Brake Cylinder (BMBC) and the method of its functioning thereof, as claimed in claim 1, wherein: -
• The basic working principle of Bogie Mounted Brake Cylinder is that the pressurized air goes into the Cylinder Body (1) and pushes the Piston Assembly (4) forward against the Return Spring (7) and Spindle Spring (6).
• Such pressurization of Piston Assembly (4) causes the Spindle Tube Assembly (8) to move forward till the Brake Shoe touches the Wheel, applying the Brake force on the Wheel.
• The Piston Screw on the Piston Assembly (4) remains engaged with the Spindle Gear on the Spindle Assembly and thus, there is no extension of the Spindle Tube Assembly (8) on the Spindle Assembly (When no Slack Adjustment is required).
• The internal construction (Clearance between Piston Assembly (4) and Cylinder Front Cover (2)) ensures that the Piston stroke of the Brake Cylinder is constant when no Slack Adjustment is required.
• When the Brake Shoes and/or the Wheel has worn out, then the clearance between the Wheel and the Brake Shoe would be increased.
• Now when the air goes into the Cylinder Body (1), the Piston Assembly (4) moves forward. It moves the Spindle Tube Assembly (8) beyond the control distance as there is a slack (there is no restraint to the Spindle Tube Assembly (8) extension).
• As the Spindle Tube Assembly (8) travels more than normal stroke, the Spindle Spring (6) pushes the Spindle Assembly and slack becomes operational to cover up the clearance.
5. Bogie Mounted Brake Cylinder (BMBC) and the method of its functioning thereof, as claimed in claim 1, wherein the method of functioning of said BMBC involves characteristic steps/features during its Brake application, as under:-
During the Brake Application, the input air pressure enters the Cylinder Body (1). This pressure acts on the Piston Assembly (4). Due to this pressure, the Piston Assembly (4) inside the Cylinder Body (1) moves in forward direction against the force of Return Spring (7) fitted inside the Cylinder Body (1). A Threaded Spindle is fitted inside the Piston Assembly (4) with the help of four Screws. The forward movement of Piston Assembly (4) moves the Spindle Tube Assy. (8) along with it, which in turn, pushes the Brake Shoe and Applies Brake, retarding the Wheel Movement.
6. Bogie Mounted Brake Cylinder (BMBC) and the method of its functioning thereof, as claimed in claim 1, wherein the method of functioning of said BMBC involves characteristic steps/features during forward and backward slack movement/position thereof, as under: -
Forward Slack: -
During repeated Brake Application, due to the rubbing of the Brake Shoe and Wheel the clearance is increased. When the clearance between the Brake Shoe and the Wheel is more than normal, then Piston Assembly (4) moves further making the Spindle Spring compress against the bearings, which is press fitted on to the Spindle Assembly. This releases the Spindle Assembly Gears inside the Piston, making it free to rotate. Now the Slack Tube Spring (9) pushes the Spindle Tube Assembly (8) outwards due to spinning movement of the Spindle Tube Assembly (8). The Spindle Tube Assembly (8) comes outwards till it touches the Wheel. Likewise, the slack takes place in the outwards direction (Pay-out).
Backward Slack: -
If the clearance between the Wheel and the Brake Shoe is lesser than normal, then Spindle Tube Assembly (8) exerts force, generated by Piston in opposite direction. This will dis-engage the Spindle Gears from Piston Assembly (4) and the Spindle Assembly rotates until it touches the other side of the gears present in the Piston. In this position, the Spindle Tube Assembly (8) collapses inwards thus creating required clearance between the Wheel and Brake Shoe. This is how the slack takes place in the inward direction (Pay-in).
7. Bogie Mounted Brake Cylinder (BMBC) and the method of its functioning thereof, as claimed in claim 1, wherein the method of functioning of said BMBC involves characteristic steps/features during its Brake Release, as under:-
Brake release: - During the release of the brake, the input pressure to the Brake Cylinder gets exhausted due to which the Return Spring retracts the Piston Assembly (4) back. Along with the Piston Assembly (4), Slack Tube Assembly (8) moves back to its initial position in turn, automatically maintaining the required clearance.
8. Bogie Mounted Brake Cylinder (BMBC) and the method of its functioning thereof, as claimed in claim 1, wherein said Bogie Mounted Brake Cylinder (BMBC) as illustrated in Figures 1 and Figure 2 is characterized in its structural, constructional and functional features, ensuring a safe and comfortable journey to the passengers, travelling in railway trains.