DESC:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

Title of invention:
A HAND WHEEL OPERATED EMERGENCY BRAKING SYSTEM FOR LOCOMOTIVES USED IN MINES

Applicant:
BEML Limited
A company Incorporated in India under the Companies Act, 1956
Having address:
BEML Soudha, 23/1, 4th Main,
Sampangirama Nagar, Bengaluru - 560 027,
Karnataka, India

The following specification particularly describes the invention and the manner in which it is
to be performed.
CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
[001] The present application claims priority from Indian provisional application no. 202041003583 filed on 27th January 2020.

TECHNICAL FIELD
[002] The present subject matter described herein, in general, relates to a braking system for a locomotive and more specifically relates to a hand wheel operated emergency braking system for a locomotive.

BACKGROUND OF THE INVENTION
[003] The battery-operated underground mine locomotives are designed for horizontal rail transport of coal in gassy mines where conditions are hazardous and explosive in nature. During the operation of the locomotive in the underground, mechanical or pneumatic or electrical service brakes are applied to reduce the speed or to halt the locomotive intermittently. If this service brake fails, it will lead to the major accident which can be sometimes fatal to the operator and also damages the machine & other properties in underground. In such circumstances, an independent emergency braking system is used to halt the locomotive safely.
[004] As per IS 9123:1979, the locomotives up to 4.5 tons of static weight have mechanical service braking system for intermittent braking and regenerative or rheostatic braking of FLP (Flame Leakage Proof) motors that can retard speed but cannot halt the locomotive. The locomotives from 8 tons to 12 tons of static weight have a pneumatic braking system as an additional safety feature. However, an additional mechanical type emergency braking system, used when service brake fails, is not available from 2.5 tons to 12 tons locomotives.
[005] In the gassy coal mines, inflammable gases are emitted during excavation of coal and it is safe to use limited electrical aggregates in machines to avoid the fire outbreak due to the ignition of gases by an electrical spark. Hence, the hand wheel operated emergency braking system configured with a fully mechanical type caliper disc brake arrangement which can be operated without any power source.

OBJECTS OF THE INVENTION
[006] Main object of the present invention is to develop the hand wheel operated emergency braking system for the battery-operated underground mine locomotive.
[007] Another object of the present invention is to design the fully mechanical type caliper disc emergency braking system that can be operated without any power source.
[008] Yet another object of the present invention is to prevent an accident in the event of service brake failure.
[009] Another object of the present invention is to reduce human efforts for applying the mechanical brake by more than 50 times.

SUMMARY OF THE INVENTION
[0010] Before the present system is described, it is to be understood that this application is not limited to the particular machine or an apparatus, and methodologies described, as there can be multiple possible embodiments that are not expressly illustrated in the present disclosures. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope of the present application. This summary is provided to introduce aspects related to the design of the hand wheel operated emergency braking system for the flame leakage proof (FLP) battery-operated underground mine locomotive, and the aspects are further elaborated below in the detailed description. This summary is not intended to identify essential features of the proposed subject matter nor is it intended for use in determining or limiting the scope of the proposed subject matter.
[0011] The present subject matter described herein, in general, relates to the design of the hand wheel operated emergency braking system for the locomotive. The service brake is used for braking of the locomotive during operation. If the service brake fails, there shall be an additional braking system to stop the locomotive to prevent fatal accident to the operator and damage to the machine. In one aspect of the present invention, the caliper discs brakes are configured to apply by the movement of the mechanical linkages based on the operation of the hand wheel operated power screw.

BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The foregoing summary, as well as the following detailed description of embodiments, is better understood when read in conjunction with the appended drawing. For the purpose of illustrating the disclosure, there is shown in the present document example constructions of the disclosure, however, the disclosure is not limited to the specific methods and apparatus disclosed in the document and the drawing:
[0013] The detailed description is described with reference to the accompanying figure. In the figure, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawing to refer like features and components.
[0014] Figure 1 illustrates 12 tons battery-operated underground mine locomotive (FLP) in accordance with one embodiment of the present subject matter.
[0015] Figure 2 illustrates the hand wheel operated emergency braking system for the locomotive used in mines in accordance with one embodiment of the present subject matter.
[0016] Figure 3 illustrates the hand wheel assembly in accordance with one embodiment of the present subject matter.
[0017] Figure 4 illustrates the mechanical linkage comprising of the links, in accordance with one embodiment of the present subject matter.
[0018] Figure 5 illustrates a brake disc in accordance with one embodiment of the present subject matter.
[0019] Figure 6 illustrates a brake caliper in accordance with one embodiment of the present subject matter.
[0020] The figure depicts various embodiments of the present disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION OF THE INVENTION
[0021] Some embodiments of this disclosure, illustrating all its features, will now be discussed in detail. The words "comprising", “having”, and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. Although any systems and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the exemplary, systems and methods are now described. The disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms.
[0022] Various modifications to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. However, one of ordinary skill in the art will readily recognize that the present disclosure is not intended to be limited to the embodiments illustrated, but is to be accorded the widest scope consistent with the principles and features described herein.
[0023] During the operation of the locomotive in underground locations, the service brake is used to reduce the speed or to halt the locomotive intermittently. If this brake fails, it will lead to a major accident which can be sometimes fatal to the operator and also damages the machine & other properties in underground. In such circumstances, an independent emergency braking system is used to halt the locomotive safely. In the gassy coal mines, inflammable gases are emitted during the excavation of coal and it is safe to use limited electrical or fully mechanical aggregates in machines to avoid the fire outbreak due to ignition of gases by an electrical spark. Hence, the emergency braking system is configured with the fully mechanical type caliper disc brakes which can be operated without any electrical/hydraulic/pneumatic power source.
[0024] Now referring to figure 1, in one aspect of the present invention, 12 ton Flame Leakage Proof (FLP) battery-operated underground mine locomotive (100) is disclosed. The hand wheel assembly (220) configured to mount in the operator’s cabin of the locomotive (100).
[0025] Now referring to figure 2 to figure 6, in one aspect of the present invention, the hand wheel operated emergency braking system (200) for the locomotive (100) is disclosed. The hand wheel operated emergency braking system (200) comprises the hand wheel assembly (220), the mechanical linkage (270), the brake discs (282) (284), the brake calipers (286) (288), clevis pins(246) (248) (250) (252) (254) (258) and adjusting nuts and bolts (264) (266) (268). The locomotive (100) comprises of two driving rail wheel axles (210) (212) with the worm gearboxes (296) (298) propelled by direct current (D.C) series motors. A worm shaft configured to connect to the motors and a worm wheel to the axle shaft. The synchronization between the motors during operation of the locomotive (100) is controlled by a Chopper controller. Two brake discs (282) (284) configured to mount at the end of the worm shaft of each worm gearbox (296) (298) with a special key arrangement and the screws (300). The two brake calipers (286) (288) are configured to mount on the housing of worm gearbox (296) (298) respectively with a clearance of 0.5mm between the brake discs (282) (284) and friction pads (290) of the brake calipers (286) (288).
[0026] The hand wheel assembly (220) comprises a lever (221), a hand wheel (222), a bearing housing (224), allen bolts (226), a bracket (228), a power screw (234), a nut (236), a pivot pin (240) and the pair of fork (242). The bracket (228) is configured to mount in the operator’s cabin of the locomotive (100). The bracket (228) configured with a vertical base plate (231), a vertical front plate (232), a horizontal plate (233), pair of bracket arms (230) and a rib (229). The vertical base plate (231) is provided with hole for mounting a bush (223) to support power screw (234) at one end. The vertical front plate (232) is provided for mounting a bearing housing (224) for intermediately supporting the bearing end of power screw (234). The bearing housing (224) configured to fix on the vertical front plate (232) with the allen bolts (226). The power screw (234) is configured for mounting the nut (236) with horizontal extensions provided for engagement of slotted ends of pair of fork (242). The horizontal plate (233) is provided for mounting the vertical base plate (231) at its one end and the vertical front plate (232) at its other end. The rib (229) is provided between the vertical base plate (231) and the vertical front plate (232) is supported on the horizontal plate (233). The pair of bracket arm (230) is configured to mount towards lower end of the vertical base plate (231) for supporting the pivot pin (240). The pair of fork (242) and link (244) are integrated and rotates on pivot pin (240). The fork end of the pair of fork (242) are configured to be slideably mounted on the two extended pin on the nut (236) adapted to move the pair of fork (242) angularly around pivotal point and thereby to provide forward and backward movement of link (244) slideably and pivotally connect to clevis pin (246).
[0027] The mechanical linkage (270) comprises the links (272) (276) (278) and across link (274). The link (272) configured to connect with the clevis pin (246) from one end and the clevis pin (248) in connection with the adjusting nut and bolt (264) to other end. Further, the cross link (274) configured to connect with the clevis pins (248) (250) (252). The link (276) configured to connect at center of the cross link (274) with the clevis pin (250) and caliper brake link (292) through the adjusting nut and bolt (266) in connection with clevis pin (254). The link (278) configured to connect with the cross link (274) through clevis pin (252) and caliper brake link (294) through clevis pin (258). Caliper brake links (292) (294) configured to connect with pivot pins (256) (260) to actuate the caliper brake (286) (288). The adjusting nuts and bolts (264) (266) (268) are configured to connect with the links (272) (276) (278) respectively for linear adjustment of the links (272) (276) (278) to adjust the clearance of 0.5mm between the brake discs (282) (284) and friction pads (290) through the linkages due to the wear in the friction pads (290).
[0028] If the service brake of the locomotive (100) fails, the operator rotates the hand wheel (222) in a clockwise direction. For effortless rotation, the hand wheel (222) configured to mount in bearing housing (224) on the vertical front plate (232) in connection with power screw (234). Due to the rotation of hand wheel (222) in clockwise direction, the power screw (234) rotates and the nut (236) travels from vertical base plate (231) towards the vertical front plate (232) and thereby moving the pair of fork (242) angularly towards the vertical front plate (232) and simultaneously pushing the link (244) in backward direction in order to push the link (272) in backward direction. The force from link (272) transfers to the link (276) through cross link (274) and moves the link (276) and caliper brake link (292) in backward direction. The caliper brake link (292) connected with pivot pin (256) will actuate the front caliper brake (286). The clevis pin joint (250) connecting to the link (276) and cross link (274) will becomes a fulcrum and further movement of link (272) moves the cross link (274) that will pull the link (278) in connection with the caliper brake link (294) in forward direction. The caliper brake link (294) connected with pivot pin (260) will actuate the rear caliper brake (288). The movement of the brake links (292) (294) will exert the force on brake calipers (286) (288) respectively and due to the friction between friction pads (290) and the rotating brake discs (282) (284) braking will happen and locomotive will halt smoothly due to incremental movement of the nut (236) on the power screw (234).
[0029] On rotating the hand wheel (222) in an anti-clockwise direction, the nut (236) travels from vertical front plate (232) towards the from vertical base plate (231). This allows the pair of fork (242) to pull the links (244) (272) to its original position. The cross link (274) connected to one end of the link (272) swings about the clevis pin joint (250) and pulls back the links (276) (278). The caliper brakes (286) (288) are released by movement of the brake links (292) (294), thereby releasing pressure on both the brake discs (282) and (284) respectively and brakes disengages.
[0030] The hand wheel operated emergency braking system (200) for the mine locomotive, the fully mechanical type caliper disc emergency braking system configured to operate without any power source.
[0031] The hand wheel operated emergency braking system (200) is configured to prevent an accident in the event of service brake failure.
[0032] The hand wheel operated emergency braking system (200) for the mine locomotive configured to reduce the human efforts for applying the mechanical brake by more than 50 times.
[0033] The Method of applying emergency braking system comprising the steps of:
rotating the hand wheel (222) for linear movement of the nut (236) for pushing the link (244) of the pivot pin assembly (240) towards the vertical base plate (231);
pushing the link (272) connected to the link (244) with the clevis pin (246) and to push one end the cross link (274) to pull the other end of the cross link (274) adapted to pull the link (278): and simultaneously pushing the link (276) for movement of caliper brake link (292) and pulling the caliper brake link (294) for application of brakes.

[0034] REFERRAL NUMERALS:
Element Description Reference Numeral
Flame Leakage Proof (FLP) Battery operated underground mine locomotive 100
Emergency Braking System 200
Front Wheel-Axle 210
Rear Wheel-Axle 212
Hand wheel assembly 220
Lever 221
Hand wheel 222
Bearing 223
Bearing housing 224
Allen Bolts 226
Bracket 228
Rib of the bracket 229
Bracket arm 230
Vertical base plate 231
Vertical front plate 232
Horizontal plate 233
Power screw 234
Nut 236
Washer with split pin 238
Pivot pin 240
Pair of fork 242
Link 244
Clevis Pin 246
Clevis Pin 248
Clevis Pin 250
Clevis Pin 252
Clevis Pin 254
Pivot Pin 256
Clevis Pin 258
Pivot Pin 260
Adjusting Nut and Bolt 264
Adjusting Nut and Bolt 266
Adjusting Nut and Bolt 268
Mechanical Linkage 270
Link 272
Cross Link 274
Link 276
Link 278
Front Brake Disc 282
Rear Brake Disc 284
Front Brake Caliper 286
Rear Brake Caliper 288
Friction pads 290
Caliper Brake Link 292
Caliper Brake Link 294
Worm Gearbox 296
Worm Gearbox 298
Screws 300

,CLAIMS:
1. A hand wheel operated emergency braking system (200) for a locomotive (100), comprising:
a hand wheel assembly (220) configured for inputting the hand force for actuation of the hand wheel operated emergency braking system (200);
a mechanical linkage (270) configured with plurality of small linkages for application of brake of the locomotive (100) by manual movement of the hand wheel assembly (220);
at least two caliper brake links (292) (294) configured to receive force from the mechanical linkage (270) to apply the force on brake calipers (286) (288) of braking system for application of brake on locomotive (100).

2. The hand wheel operated emergency braking system (200) as claimed in claim 1, wherein said hand wheel assembly (220) is configured with a hand wheel (222), a bracket (228), a bearing housing (224), a power screw (234), a nut (236), pair of fork (242), a link (244) and a pivot pin (240) ; wherein the hand wheel (222) is provided with a lever (221) mounted perpendicularly on its periphery and a central boss with hole on the hand wheel (222) is provided for mounting one end of the power screw (234);
wherein said bracket (228) is configured with a vertical base plate (231), a vertical front plate (232), a horizontal plate (233), pair of bracket arm (230) and a rib (229), wherein said vertical base plate (231) is provided with hole for mounting a bearing (223) to support other end of power screw (234), wherein the horizontal plate (233) is provided for mounting the vertical base plate (231) at its one end and the vertical front plate (232) at its other end, a rib (229) is provided between the vertical base plate (231) and the vertical front plate (232) is supported on the horizontal plate (233), wherein the pair of bracket arms (230) is mounted towards lower end of the vertical base plate (231) for supporting the pivot pin (240), wherein said vertical front plate (232) is provided for mounting a bearing housing (224) for supporting the power screw (234) at the bearing surface.

3. The hand wheel operated emergency braking system (200) as claimed in claim 1, wherein the power screw (234) is configured for mounting the nut (236) with horizontal extensions provided for engagement of slotted ends of pair of fork (242).

4. The hand wheel operated emergency braking system (200) as claimed in claim 1, wherein said pair of bracket arms (230) are configured with the holes for mounting of the pivot pin (240) wherein the pair of fork (242) and link (244) are integrated and rotates on pivot pin (240).

5. The hand wheel operated emergency braking system (200) as claimed in claim 1, wherein said nut (236) is provided with two horizontally extended pins on its side facing configured for engagement of the fork end of the pair of fork (242) adapted to rotate on the pivot pin assembly (240) to provide forward and backward swing movement of link (244) and clevis pin (246).

6. The hand wheel operated emergency braking system (200) as claimed in claim 1, wherein the mechanical linkages (270) is configured with the links (272) (276) (278), a cross link (274) to transfer the force from the hand wheel (222) through the clevis pins (246) (248) (250) (252) (254) (258), wherein the link (272) is provided with the clevis pin (246) from one end and the clevis pin (248) in connection with the adjusting nut and bolt (264) to other end to push the cross link (274), wherein the cross link (274) configured to connect with the clevis pins (248)(252) from both ends and the link (276) and clevis pin (250) at centre becomes a fulcrum to pull the links (276) (278) in forward direction, wherein the link (276) configured to connect with the cross link (274) through clevis pin (250) and caliper brake link (292) through clevis pin (254) to transfer the force to caliper brake link (292) for actuating the front caliper brake (286), wherein the link (278) configured to connect with the link (274) through clevis pin (252) and caliper brake link (294) through clevis pin (258) in connection with the adjusting nut and bolt (268) to transfer the force to caliper brake link (294) for actuating the rear caliper brake (288).

7. The hand wheel operated emergency braking system (200) as claimed in claim 1, wherein said links (272) (276) (278) are configured with the adjusting nuts and bolts (264) (266) (268) respectively for linear adjustment of the links (272) (276) (278) to maintain predetermined clearance between the brake discs (282) (284) and friction pads (290) of the caliper brakes.

8. The hand wheel operated emergency braking system (200) as claimed in claim 1, wherein the two caliper brakes (286) (288) configured to mount on a housing of the worm gearbox(296) (298) with clearance of 0.5 mm between the two brake discs (282) (284) and the friction pads (290) of the two caliper brakes (286) (288).

9. The method of applying emergency braking system and method of its application comprising the steps of:
• rotating the hand wheel (222) in clockwise direction for linear movement of the nut (236) for pushing the link (244) about the pivot pin assembly (240) towards the vertical base plate (231);
• pushing the link (272) connected to the link (244) with the clevis pin (246) and to push one end the cross link (274) to pull the other end of the cross link (274) adapted to pull the link (278): and simultaneously pushing the link (276) for movement of caliper brake link (292) and pulling the caliper brake link (294) for application of brakes.