The present invention generally relates the mechanism of Locomotive Brake Unit (LBU) containing both Service Brake and Parking Brake functioning independently and as combined (as shown in schematic figure 2), wherein said mechanism of Locomotive Brake Unit (LBU) is applicable to 6-Axled Locomotives, generally contain Twelve Brake units and four of them are coupled with Parking Brake Devices. The complete Brake Unit (LBU) of the instant invention, as schematically depicted in Figure 2, is uniquely designed, compact, light in weight, economical and maintenance-friendly. The Service Brake unit contains a pneumatically actuated Cylinder along with Automatic Slack Adjusting mechanism connecting to Brake shoes to apply load normal to the Wheel tread. The Parking Brake device is coupled with Service Brake Unit to function during Parking Brake application.

BACKGROUND AND PRIOR ARTS:
Most relevant prior art for the instant invention as described hereinbelow with the illustrations in Figures 2 to 8, is US3430739A, titled as RAILWAY VEHICLE BRAKE RIGGING, filed on 18th August 1967 and granted on 04th March 1969.
Figure 1 hereinbelow indicates figures taken from the said prior art US340739A. Said prior patent US3430739A disclosed a railway brake system with a compact brake rigging affixed to a housing on the vehicle is disclosed including bidirectional slack adjusting means relatively movable with respect to the housing. The slack adjusting means comprises an axially displaced push transmitter receiving a compression force and having a threaded spindle and locking nut thereon affixed in a relatively positionable telescoping sleeve with means for adjusting the relative position by rotating the nut in either direct to hold a predetermined degree of slack. In order to reduce the space in which the brake rigging is mounted, the entire slack adjusting linkage assembly pivots on respective levers about an arc defined by two fixed pivot points on the fixed housing, and intervenes between a brake power cylinder and the movable braking assembly to permit a compression force to be transmitted therethrough. A series of springs and clutches co-act to cause the nut to rotate in the proper direction when brakes are actuated to compensate and correct the slack in the brake linkage whenever slack 'becomes too great from wear or too little when new brake-shoes are installed. One such spring holds the telescoping parts in tension and co-acts with the compressive braking force to aid in determining the position during application of the brakes that the slack take up and let out operations occur.
Further, it explains a brake rigging of the kind referred to has a pair of levers pivotally mounted 1n said housing and connected to a slack `adjuster or push transmitter to pivot it through an arc, wherein a spring force source is inserted 'between the two levers for establishing a tension force between two relatively positioned push transmitter parts locked in place by locking means, and including means for disengaging said locking means in response to variations from a predetermined amount of slack in the brake rigging, and means adjusting the degree of slack as the brakes are applied.
Said invention of US3430739A relates to a railway vehicle brake rigging of the kind comprising a bidirectional slack adjuster within a housing for actuation by a power cylinder rigidly secured to said housing.
Brake riggings of the kind referred to are often referred to as compact brake riggings or brake units, and they are frequently used on vehicles in which the space available for the rigging is very restricted. Hitherto such compact riggings have either been provided with manual slack adjusters or with slack adjusters which are automatic only in the direction for reducing the slack. United States Patent 2,767,811 is representative of non compact bidirectional slack adjusters. Formerly known bidirectional slack adjusters are not adaptable to compact bidirectional action because they have not been affixed to the vehicle housing for movement relative thereto and because of operation in a tension rather than compression mode, and have sometimes introduced large and undesirable variations in braking forces as loads vary and as brakes wear.
Subject matter said patent US3430739A mainly tried to provide several technical solutions relating to railway brake system, namely:
• A brake rigging of the kind referred to but including a double-acting and rapid-acting automatic slack adjuster providing improved performance over prior art devices. One object of said patent US3430739A was to provide such a compact rigging requiring such little space that the greater part thereof may be mounted within the interior of the bolster of a railway bogie.
• A brake rigging which may be completely installed in the separate bolster ICC to the assembling of the bogie or of the entire vehicle.
• A brake rigging of the kind referred to has a pair of levers pivotally mounted in said housing and connected to a slack `adjuster or push transmitter to pivot it through an arc, wherein a spring force source is inserted 'between the two levers for establishing a tension force between two relatively positioned push transmitter parts locked in place by locking means, and including means for disengaging said locking means in response to variations from a predetermined amount of slack in the brake rigging, and means adjusting the degree of slack as the brakes are applied. The adjustment is accomplished when two telescoping members move relative to a fixed housing under direction of a compressional braking force and against the force of a loading spring tending to hold them apart in tension. The rotatable nut is freed during an intermediate travel range when the braking force overcomes the loading spring tension, but the nut is locked in place at each end of the range. In one embodiment, a slack take up adjusting spring is held at both ends within the housing `and is engaged by the nut after a predetermined axial travel of the spindle by means of the braking force, so that the nut can be rotated by the slack take up adjusting spring only during a portion of the movement in the intermediate travel range when the nut is exposed to a force from the slack take up adjusting spring which is slightly greater than the force of the loading spring tending to hold the two telescoping members apart.
SUMMARY OF THE INVENTION:
The present invention discloses a novel The invention is related to the mechanism of Locomotive Brake Unit (LBU) containing both Service Brake and Parking Brake functioning independently and in combined manner too. Locomotive Brake Unit is a pneumatically driven foundation Brake actuating device attached along with the Parking Brake Cylinder. The Service Brake Unit primarily contains a Brake Cylinder, integral Piston-Wedge and Automatic Slack Adjuster assembly. The design is unique with respect to Piston and Wedge mechanism, Automatic Slack adjustment, compactness in size and design simplicity.
Short description of the drawings:
Figure 1 hereinbelow indicates figures taken from the said prior art US340739A.
Figure 2: Locomotive Brake Unit (LBU) – Service Brake With Parking Brake
Figure 3: LOCOMOTIVE BRAKE UNIT (LBU)-SERVICE BRAKE
Figure 4: Schematic cross-sectional view of the LBU assembly, particularly to show Service Brake Unit.
Figure 5: Schematic side view of the LBU assembly of the instant invention, showing its major components thereof.
Figure 6: Schematic cross-sectional view of the internal arrangement of components, assembled within the Brake Unit of the instant invention, mainly responsible for performing automatic Slack Adjustment.
Figure 7: Schematic cross-sectional view of the internal arrangement of components, assembled within the Brake Unit of the instant invention, mainly responsible for performing Parking brake (Spring Actuator).
Figure 8: Schematic view of the Latch (21) provided at the side of Parking Brake Cylinder in the LBU assembly of the instant invention.
List of numeric references and their details:-
Numeric reference Details of the numeric reference, describing the structural/ constructional feature
1 Brake Shoe Block
2 the Brake Shoe
3 Shoe Return Spring
5 Service Brake Cylinder
6 Spindle-1
7 Slack Adjuster assembly,
8 Return Spring
11 Piston-1
12 Piston-2
13 Thrust Nut (13)
14 Spindle-2 (14)
16 Spring seat bottom
18 Clutch
21 Latch provided at the side of Parking Brake Cylinder in the LBU assembly
27 Stopper
28 Slider
29 Control Sleeve
30 Gear Support (30)
31 Splined Hub
32 Spring set assembly (32)
34 Parking Brake Cylinder
DETAILED DESCRIPTION OF THE INVENTION:
6-Axled Locomotives generally contain twelve brake units and four of them are coupled with Parking Brake Devices. The invention is related to the mechanism of Locomotive Brake Unit (LBU) containing both Service Brake and Parking Brake functioning independently and in combined manner too (as shown in schematic figure 2). The complete Brake Unit is uniquely designed, compact, light in weight, economical and maintenance-friendly. The Service Brake unit contains a pneumatically actuated Cylinder along with Automatic Slack Adjusting mechanism connecting to Brake shoes to apply load normal to the Wheel tread. The Parking Brake device is coupled with Service Brake Unit to function during Parking Brake application.
PRINCIPLE OF OPERATION
The Locomotive Brake Unit is a pneumatically driven foundation Brake actuating device attached along with the Parking Brake Cylinder. The Service Brake Unit primarily contains a Brake Cylinder, integral Piston-Wedge and Automatic Slack Adjuster assembly. The design is unique with respect to Piston and Wedge mechanism, Automatic Slack adjustment, compactness in size and design simplicity.
The uniquely designed Parking Brake unit, contains components which are initially held at the bottom of the Parking Brake Chamber under Pressure during Parking Brake release condition. When the Parking Brake is applied by the Loco pilot, the pressure in the Parking Brake chamber is released and the components get actuated using Springs pushing the Service Brake Piston up and therefore enabling mechanical braking.
Due to the compactness of design, the whole Brake Unit can be conveniently positioned in the Bogie, making it suitable for installation in Locomotive Bogies with limited space.
Said novel design of the complete Locomotive Brake Unit (LBU) assembly, as disclosed herein and illustrated in drawings 2-8 are being discussed with respect to its structural and functional mechanisms under separate heads of ‘Service Brake Unit’ and ‘Parking brake (Spring Actuator)’.
Service Brake Unit (Ref. Figures 4-6)
1. Brake Application (Ref. Figure 4)
Compressed air at the required pressure, flows into the Service Brake Cylinder (5) through the Inlet Port ( ) and moves the Piston (11) up for brake application. As the Piston moves up, the two Wedges, which are integral to Piston (11), provide corresponding translational movement for the Slack Adjuster assembly (7), against the Shoe Return Spring (3), through the Rollers sliding on the Wedge angle. This translational movement, pushes the Brake Shoe (2) through Spindle-1 (6) enabling Braking.
2. Brake Release (Ref. Figure 5)
The pressure inside the Brake Cylinder Unit is exhausted to enable Brake Release. As the pressure is released, all parts are retracted back to the initial position using the Return Springs (3 & 8).
3. Automatic Slack Adjustment (Ref. Figure 6)
Automatic Slack Adjuster mechanism comes into action when the clearance between Shoe and Wheel increases beyond recommended value, due to repeated brake applications.
In this condition, the Slack Adjuster assembly along with Spindle-1 (6) & Brake Shoe (2), Stopper (27) stops the Slider (28) to control free travel. The Slider (28), engaged with Control Sleeve (29) also gets stopped allowing Gear Support (30) to get disengaged from Control Sleeve which causing gap between them and Control Sleeve moves on the Spindle further to the extent of excess clearance between Wheel and Brake Shoe. The extra travel other than free travel is considered as slack. When air is released from Brake Cylinder Chamber, the whole Slack Adjuster assembly (7) comes back to its initial position.
4. Brake Reset (Ref. Fig. 6)
To change the worn out Brake Shoe Block (1), there is a reset mechanism provided at the other end of the Slack Adjuster assembly. The whole unit containing Brake Shoe Block (1), Brake Shoe (2) and Spindle-1 (6) will come back to their normal position by rotating Splined Hub (31), as needed.
Parking brake (Spring Actuator) (Ref. Figures 7-8)
In a normal condition, the pressurized air is filled inside the Parking Brake chamber holding down all the components against the Spring force.
1. Brake Application (Ref. Fig. 7)
When the Loco pilot applies the Parking brake, the air pressure inside the chamber is released causing the Parking Brake Cylinder (34), Spring set assembly (32) along with Clutch (18), Thrust Nut (13) to move to their free assembly position due to Springs This upward movement lifts Spindle-2 (14) & Piston-1 (11) through Thrust Nut (13), in turn, pushing the Service Brake Cylinder Piston causing the mechanical application of Service Brake.
2. Brake Release (Ref. Fig. 7)
When the Loco pilot releases Parking Brake, which implies, pressurised air is let inside the Parking Brake Chamber. In this condition, the unit comprising Piston-2 (12), Clutch (18), Thrust Nut (13), Spring Set Assy (32) and Spindle-2 (14) move down against Spring force. This in turn brings back Shoes and Service Brake components also to their initial position.
3. Manual Brake Release (Ref. Fig. 8)
When the pressurised air is not available due to some reasons and if Loco Pilot is needed to release brakes, the Latch (21) provided at the side of Parking Brake Cylinder to trigger Manual Brake Application.
When the Latch (21) is pulled out, Spring seat bottom (16), Spring set (32), Clutch (18), Thrust Nut (13) become a single unit and rotate due to thrust load on Spindle-2 (14) generated by Piston-1 (11) and Return Spring (8) causing Spindle-2 (14) to move down. At this condition, due to Return Springs’ (3 and 8) force, Brake Shoe (2) unit & Slack Adjuster Assembly (7) move up to their free normal position causing mechanical application of Service Brake.
Advantages of Locomotive Brake Unit (LBU) of the invention and its unique breaking mechanism:
i. Unique in design
ii. Easy to handle
iii. Compact in size, hence can fit into Bogies with limited space
iv. Lesser number of parts thus requiring lesser maintenance
v. More reliable due to lesser number of parts
vi. Robust and strong, giving a better life
vii. Suitable for use in heavy and high-speed Locomotives
Although a preferred embodiment of the invention has been illustrated and described/illustrated, 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 claims, and not by the foregoing specification, when interpreted in light of the relevant prior art.

WE CLAIM:-

1.Locomotive Brake Unit (LBU), comprising Service Brake Unit, Parking Brake Unit and Brake Shoe Block; wherein the complete Brake Unit (LBU) is uniquely designed, compact, light in weight, economical and maintenance-friendly and the said Locomotive Brake Unit (LBU) is characterized in its breaking mechanism involving the Service Brake and Parking Brake, both functioning independently as well as in combined manner.
2. The Locomotive Brake Unit (LBU), as claimed in claim 1, wherein the Service Brake unit contains a pneumatically actuated Cylinder along with Automatic Slack Adjusting mechanism connecting to Brake shoes to apply load normal to the Wheel tread; wherein the Parking Brake device is coupled with Service Brake Unit to function during Parking Brake application.
3. The Locomotive Brake Unit (LBU), as claimed in claim 1 or 2, wherein the Service Brake Unit and its mechanism of breaking includes the following:
(a) Brake Application (Ref. Figure 4):-
Compressed air at the required pressure, flows into the Service Brake Cylinder (5) through the Inlet Port ( ) and moves the Piston (11) up for brake application. As the Piston moves up, the two Wedges, which are integral to Piston (11), provide corresponding translational movement for the Slack Adjuster assembly (7), against the Shoe Return Spring (3), through the Rollers sliding on the Wedge angle. This translational movement, pushes the Brake Shoe (2) through Spindle-1 (6) enabling Braking.
(b) Brake Release (Ref. Figure 5):-
The pressure inside the Brake Cylinder Unit is exhausted to enable Brake Release. As the pressure is released, all parts are retracted back to the initial position using the Return Springs (3 & 8).
(c) Automatic Slack Adjustment (Ref. Figure 6):-
Automatic Slack Adjuster mechanism comes into action when the clearance between Shoe and Wheel increases beyond recommended value, due to repeated brake applications. In this condition, the Slack Adjuster assembly along with Spindle-1 (6) & Brake Shoe (2), Stopper (27) stops the Slider (28) to control free travel. The Slider (28), engaged with Control Sleeve(29) also gets stopped allowing Gear Support (30) to get disengaged from Control Sleeve which causing gap between them and Control Sleeve moves on the Spindle further to the extent of excess clearance between Wheel and Brake Shoe. The extra travel other than free travel is considered as slack. When air is released from Brake Cylinder Chamber, the whole Slack Adjuster assembly (7) comes back to its initial position.
(d) Brake Reset (Ref. Fig. 6):-
To change the worn out Brake Shoe Block (1), there is a reset mechanism provided at the other end of the Slack Adjuster assembly. The whole unit containing Brake Shoe Block (1), Brake Shoe (2) and Spindle-1 (6) will come back to their normal position by rotating Splined Hub (31), as needed.
4. The Locomotive Brake Unit (LBU), as claimed in any of preceding claims 1 to 3 hereinabove, wherein the Parking brake (Spring Actuator) and its mechanism of breaking includes the following:
In a normal condition, the pressurized air is filled inside the Parking Brake chamber holding down all the components against the Spring force.
(a) Brake Application (Ref. Fig. 7):-
When the Loco pilot applies the Parking brake, the air pressure inside the chamber is released causing the Parking Brake Cylinder (34), Spring set assembly (32) along with Clutch (18), Thrust Nut (13) to move to their free assembly position due to Springs This upward movement lifts Spindle-2 (14) & Piston-1 (11) through Thrust Nut (13), in turn, pushing the Service Brake Cylinder Piston causing the mechanical application of Service Brake.
(b) Brake Release (Ref. Fig. 7):-
When the Loco pilot releases Parking Brake, which implies, pressurised air is let inside the Parking Brake Chamber. In this condition, the unit comprising Piston-2(12), Clutch (18), Thrust Nut (13), Spring Set Assy (32) and Spindle-2(14) move down against Spring force. This in turn brings back Shoes and Service Brake components also to their initial position.
(c) Manual Brake Release (Ref. Fig. 8):-
When the pressurised air is not available due to some reasons and if Loco Pilot is needed to release brakes, the Latch (21) provided at the side of Parking Brake Cylinder to trigger Manual Brake Application. When the Latch (21) is pulled out, Spring seat bottom (16), Spring set (32), Clutch (18), Thrust Nut (13) become a single unit and rotate due to thrust load on Spindle-2 (14) generated by Piston (1) and Return Spring (8) causing Spindle-2 (14) to move down. At this condition, due to Return Springs’ (3 and 8) force, Brake Shoe (2) unit & Slack Adjuster Assembly (7) move up to their free normal position causing mechanical application of Service Brake.
5. Locomotive Brake Unit (LBU), as claimed in any of preceding claims 1 to 3 hereinabove, wherein unique structural assembly and designs thereof enables said Locomotive Brake Unit (LBU) towards operating its Service Brake and Parking Brake, either independently as well as in combined manner.