DESC:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patent Rules, 2003
COMPLETE SPECIFICATION
(See sections 10 & rule 13)
1. TITLE OF THE INVENTION
A FIRE RESISTANT BACK WALL SYSTEM WITH DOUBLE LEAF DOOR
2. APPLICANT (S)
NAME NATIONALITY ADDRESS
BEML LIMITED IN BEML Soudha, No 23/1, 4th Main S.R. Nagar, Bengaluru- 560027, Karnataka, India.
3. PREAMBLE TO THE DESCRIPTION
COMPLETE SPECIFICATION

The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF INVENTION:
[001] The present invention relates to the field of fire resistance system for railway vehicle. The present invention in particular relates to a fire resistant back wall system with double leaf door and its method thereof.
DESCRIPTION OF THE RELATED ART:
[002] In the fight against fire, the assembly head-sliding doors at the head of railway vehicles must resist for a certain time to the fire coming from the adjacent vehicle, so as to allow the passengers to escape from the boarding doors.
[003] In the presence of fire, the door in the junction area between the mobile leaves is very vulnerable, subject to considerable deformations, due to the thermal expansion of the covering plates, which can cause the passage of fire and fumes towards the interior of the vehicle.
[004] Reference may be made to the following:
[005] Publication No. ITFI950065 relates to the fight against fire, the assembly of head and sliding doors of railway vehicles must withstand for 30 minutes a fire coming from the adjacent vehicle to allow for the escape of passengers through the exit doors. In the presence of fire, the door in the junction zone between the movable wings proves very vulnerable, where deformations occur due to thermal expansion, resulting in the passage of fire and smoke into the vehicle.
[006] Publication No. DE2208349 relates to the hydraulic door closer is used for fire protection doors of large goods carriers e.g. ships or railway vehicles. The damper of the door closer is a separate unit with parallel compensation and damping chambers. The compensation element is a piston sliding in the compensation chamber. The damper chambers on either side of the damping piston are connected by channels to ensure damping when the piston approaches the closed position. The compensation chamber is connected to a damping chamber by a channel.
[007] Publication No. CN212369448 discloses a fire extinguisher cabinet with an alarm function for quickly opening a railway vehicle, which comprises a fire extinguisher cabinet main body, a cabinet door, a push-type locking mechanism, a buzzer, a connector and a limit switch, the fire extinguisher cabinet main body is connected with the cabinet door through a hinge, and the push-type locking mechanism is arranged on the cabinet door. A lock catch is arranged on the fire extinguisher cabinet body, and a spring bolt and the lock catch of the push type locking mechanism are matched with each other to achieve locking. The limiting switch is installed in the fire extinguisher cabinet body, a push rod of the limiting switch is connected with a button column of the push-press type locking mechanism and the limiting switch, the buzzer is installed on a rail vehicle, the fire extinguisher cabinet is uploaded to a train network in the open state, alarm sound is sent out, and alarm reminding is achieved.
[008] Publication No. CN208101807 provides a multifunctional fire -fighting propaganda vehicle, including the automobile body, be equipped with the carriage on the automobile body, the LED display screen has integrated on the railway carriage or compartment wall in carriage, the diapire in carriage is formed by main frame, braced frame and splice plate equipment, form a plurality of concatenation spaces between main frame, first support stock, first support quarter butt and the second support quarter butt, the upper portion that concatenation space, splice plate were passed to the lower part of splice plate is passed through screw locking and is fixed on corresponding main frame, first support stock, first support quarter butt or second support quarter butt, the utility model discloses have the propaganda function, body group dress in railway carriage or compartment is convenient, has improved the packaging efficiency, and the cost is reduced has improved the security performance.
[009] Publication No. KR200455704 relates to a fire damper for an air duct, and more specifically, it is installed between the distribution pipe of the air duct and a flexible duct connected to the kitchen and bathroom sides so that flames and toxic gases caused by fire can block the ventilation holes of the kitchen or bathroom. It not only prevents the inflow and spread of the indoor living space and the indoor living space of other neighboring households, but also discharges odors and polluted air generated from kitchens and bathrooms inside the building to the outside, making the indoors pleasant and it relates to a fire damper for an air duct to block odors, polluted air, noise, etc. discharged from kitchens and bathrooms on upper and lower floors from flowing back into the interior.
[010] Publication No. KR20200114961 relates to a fiber refractory duct pipe unit, and a heat-insulated duct installation method using the same. The fiber refractory duct pipe unit comprises: a duct framework unit for maintaining the framework of a duct; a support structure provided in an intermediate area of the duct framework unit a fiber refractory sheet and a fixing frame. According to the present invention, the risk of fire can be prevented in advance.
[011] Publication No. KR20220000163 relates to a fireproof damper for a duct, which normally does not disturb the flow of air flowing in a duct, improves fire spreading prevention performance by expanding thermally while automatically blocking the gap between a fireproof damper and the duct when a fire occurs, and improves thermal insulation performance to obtain t-class heat insulation performance in a fire resistance test of a metallic duct (pipe) to reduce the usage of a heat insulation material constructed on the outer surface of the duct. According to an embodiment of the present invention, the fireproof damper for a duct comprises: a damper body having a box or a cylindrical shape of which both ends are opened to connect the gap between ducts; a thermal-expansion fire-resistant curtain made of a flexible thermal-expansion resin material expanding by heat, wherein the upper end thereof is fixed between one end of the damper body and the connection part of ducts, and the lower end thereof is separably fixed on the upper end of a duct such that the lower end thereof is normally fixed on the upper end of the duct, and the lower end thereof is separated from the upper end of the duct by heat and falls to block the space between one end of the damper body and the duct when a fire occurs; and a curtain fixing means separably fixing the lower end of the thermal-expansion fire-resistant curtain on the upper end of the duct.
[012] Patent No. US9976341 relates to a firewall access door includes a rectangular door frame with a rectangular door coupled there to by at least one door hinge. The door consists of a first rectangular pan member and a decorative gypsum wall panel mated together. The door further includes a second rectangular pan member having a flat surface with opposite side walls extending perpendicular from a flat surface of the second rectangular pan member. The side walls of the second rectangular pan member have flanges for mounting to a back surface of the first pan member opposite the gypsum panel and adjacent the side walls of the first rectangular pan member. The second pan member spans the back of the first rectangular pan member and forms an air gap between the flat surface and the back of the rectangular pan member.
[013] Publication No. EP0742338 relates to the chipboard core has covering layers on the inside and outside also glued components along the top and side edges. These comprise an outer wooden strip and an inner fire-resistant one contg. Sodium silicate, also a further layer if desired. At the glued components, a peripheral groove is milled in the chipboard, and in which a stabiliser strip is inserted and glued. The strip can comprise a middle layer between outer ones, these running parallel to the edges and at right angles to the inside and outside. The middle layer can be a hard fibre plate, and the outer ones medium-hard fibre plates. The covering layer can also be a hard-fibre plate.
[014] Publication No. DE4234800 relates to an air-guiding channel with an inserted fire shutter which is mounted rotatably, via a pin or the like, in sidewalls of the air-guiding channel and is held in an open position by a safety device or a safety switch. In the case of said air-guiding channel, the pin is to be assigned a drive element which interacts with an actuating element.
[015] The existing design of the back wall with double leaf door will not prevent the fire passing from passenger area to driver cab area due to gaps between the doors and the wall. One of the doors of double leaf contains emergency access window with breakable cover which can be directly opened to cab area by breaking breakable cover and operating the cab side handle from passenger side. Cab side door handle is visible from the passenger area through the emergency access window opening which will not prevent the fire passing from passenger area to driver cab area. Fire dampers are not provided in the air conditioning duct passing through back wall and in the ventilation grilles (14) in the bottom of the backwall. Hence there needed a system that can protect the driver in driver cab of a railway vehicle during fire.
[016] In order to overcome above listed prior art, the present invention aims to provide a fire resistant back wall system with double leaf door for driver protection to protect the driver in driver cab of a railway vehicle with fire resistant Back wall with double leaf door, in case of fire in passenger area. The proposed invention protects the driver in driver cab of a railway vehicle with fire resistant back wall with double leaf hinged door, in case of fire in passenger area, the backwall protects the driver from fire with a fire integrity of minimum 10 minutes, which in turn helps the driver to take the train where there are stations or rescue stations that offer a place of safety to passengers, reachable within a short running time.
OBJECTS OF THE INVENTION:
[017] The principal object of the present invention is to provide a fire resistant back wall system with double leaf door and its method thereof.
[018] Another object of the present invention is to provide a system to protect the driver in driver cab of a railway vehicle.
SUMMARY OF THE INVENTION:
[019] The present invention relates to the fire resistant back wall system with double leaf door. Thus, the invention provides improved backwall with double leaf door to prevent fire passing from passenger area to driver cab area. Special locking arrangements are provided for the emergency access window of the backwall to prevent fire passing from passenger area to driver cab area. Fire damper in air conditioning duct passing through the backwall prevents fire passing from passenger area to driver cab area.
BREIF DESCRIPTION OF THE INVENTION
[020] It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments.
[021] Figure 1, 2 and 3 shows fire resistant back wall system with double leaf door according to the present invention;
[022] Figure 4 shows flow diagram according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION:
[023] The present invention provides the fire resistant back wall system with double leaf door. The back wall (1,2,3) with double leaf door (4,5) i.e., master leaf (4) and secondary leaf (5) is provided with special profile aluminum extrusions (6), aluminium honeycomb panels (7), special locks (8), special hinges (9) and intumescent strips (10). The system (fig 1 and 2) ensures that Intumescent strips (10) expand with increase in temperature due to fire and prevents the flame. Emergency access window (11) in the door leaf has been provided with locking arrangement(8). containing extra handle (16) on saloon side along with cab side handle (17) and both handles are interconnected which eliminates the emergency access window opening which will results fire prevention from passenger side to cab side. Fire dampers (13) are provided in air conditioning duct passing through the back wall from passenger area to driver cab area. Fire dampers (13) have also been provide in the bottom ventilation grille (14) of the backwall (1,2). Figure 4 shows flow diagram according to the present invention.
[024] The backwall prevents the fire passing from passenger area to driver cab area and closing the emergency access window with special locking arrangement (8). Fire dampers (13) are provided in the air conditioning duct passing through back wall and in the ventilation grilles(14) in the bottom of the backwall.
[025] In case of fire in passenger area fire resistant back wall system with double leaf door will and prevents the fire passing from passenger area to driver cab area. The intumescent strips (10) provided in the system will expand with increase in temperature due to fire and prevents the fire passing from passenger area to driver cab area.
[026] The cross-sectional shapes (fig 3) of the special aluminium extrusions (6) with flanges (15) provided in the closing edge of the door leaves with the intumescent strips (10) helps in the prevention of fire passage. Aluminium extrusions (6) having the intumescent strips (10) will expand with increase in temperature due to fire and will come in contact with flanges of the aluminium extrusions (6) helps in restricting the intumescent gasket expansion and blocking the gaps between door leaves and prevents the fire passing from passenger area to driver cab area.
[027] Purpose of Secondary leaf (5)
? Permit train driver entry and exit between the saloon area to the cab area.
? Prevent passenger entry from the saloon area to the driver cab area.
[028] Purpose of Master Leaf (4)
? In the event of an emergency, provide passenger access to cab by breaking breakable cover and operating the emergency handle.
? Prevent passenger entry from the saloon area to the cab area when the train is in service.
[029] Master leaf will be having the locking mechanism of the door, which were to be locked on top and bottom with upper and lower catcher respectively, which will be operated with the lever at cab side. In normal situation master leaf lock can only be operate from cab side and not from saloon side.
[030] Special locking arrangement (8) is provided, in case of emergency while operation of master leaf handle on saloon side, secondary lock (18) also will be disengaged and both doors can be opened from saloon side towards cab side.
[031] The special lock arrangement (8) contains extra handle (16) on saloon side along with cab side handle and both handles are interconnected which eliminates the emergency access window opening which will results fire prevention from passenger side to cab side. Special hinge (9) having one leaf with less width (19) which will allow the intumescent strips (10) to expands with increase in temperature due to fire and prevents the fire passing from passenger area to driver cab area.
[032] Thus, the aluminium honeycomb panels made of aluminium honey comb core with aluminium sheets of different thickness are used to achieve fire resistance with 3mm thick aluminium sheet and driver cab side with 1.5mm thick aluminium sheet to achieve the requirement of fire barrier.
[033] Special profile aluminium extrusions (6) with flanges (15) provided in the closing edge of the door leaves with the intumescent strips (10) helps in the prevention of fire passage.
[034] Special hinge (9) having one leaf with less width (19) which will allow the intumescent strips to expand with increase in temperature due to fire and blocks the gap between the hinge and prevents fire propagation.
[035] Special locking arrangement (8) contains extra handle (16) on saloon side along with cab side handle (17) and both handles are interconnected which eliminates the emergency access window opening which will results fire prevention from passenger side to cab side. Also, in case of emergency while operation of master leaf extra handle (16) on saloon side, secondary lock (18) also will be disengaged and both doors can be opened from saloon side towards cab side.
[036] Fire dampers (13) provided in air conditioning duct passing through the back wall from passenger area to driver cab area.
[037] The ventilation grilles (14) are provided in bottom portion of the backwall (1,2). In case of fire the ventilation grilles (14) will prevent the fire propagation from passenger area to driver cab area.
[038] Thus, the invention provides improved backwall with double leaf door to prevent fire passing from passenger area to driver cab area. Special locking arrangements (8) are provided for the emergency access window of the backwall to prevent fire passing from passenger area to driver cab area. Fire dampers (13) in air conditioning duct passing through the backwall prevents fire passing from passenger area to driver cab area.
[039] Numerous modifications and adaptations of the system of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the true spirit and scope of this invention.
,CLAIMS:WE CLAIM:
1. A fire resistant back wall system with double leaf door. comprises-
a) Back wall (1,2,3) with double leaf door (4,5) and Aluminum extrusions (6), wherein backwall prevents the fire passing from passenger area to driver cab area and closing the emergency access window with special locking arrangement (8).
b) Aluminium honeycomb (7) Door panels (4,5), characterized in that aluminium sheets with aluminium honeycomb core assembled by bonding. Saloon side will be provided with 3mm thick aluminium sheet and driver cab side with 1.5mm thick aluminium sheet achieve the requirement of fire barrier.
c) Locking arrangement (8) contains extra handle (16) on saloon side along with cab side handle (17) and both handles are interconnected which eliminates the emergency access window opening which will results fire prevention from passenger side to cab side. Also, in case of emergency while operation of Master leaf extra handle (16) on saloon side, secondary lock (18) also will be disengaged and both doors can be opened from saloon side towards cab side.
d) Special hinge (9) characterized in that one leaf with less width (19) which will allow the intumescent strips to expand with increase in temperature due to fire and blocks the gap between the hinges and prevents fire propagation.
e) Intumescent strips (10) that expands with increase in temperature due to fire and prevents the flame.
f) Emergency access window (11) in the door leaf characterized in that extra handle (16) on saloon side along with cab side handle and both handles are interconnected which eliminates the emergency access window opening which will results fire prevention from passenger side to cab side locking arrangement (8).
g) Fire dampers (13) provided in air conditioning duct passing through the back wall from passenger area to driver cab area in the bottom ventilation grilles (14) of the backwall (1,2)
h) The ventilation grilles (14) at the bottom portion of the backwall (1,2) wherein in case of fire the ventilation grilles (14) will prevent the fire propagation from passenger area to driver cab area.
2. The fire resistant back wall system, as claimed in claim 1, wherein during fire in passenger area fire resistant back wall system with double leaf door will and prevents the fire passing from passenger area to driver cab area. The intumescent strips (10) provided in the system will expand with increase in temperature due to fire and prevents the fire passing from passenger area to driver cab area.
3. The fire resistant back wall system, as claimed in claim 1, wherein the fire dampers (13) are provide above the partition wall where the airduct is passing from passenger area to driver cab area and in case of fire the fire dampers will prevent the fire propagation from passenger area to driver cab area.
4. The fire resistant back wall system, as claimed in claim 1, wherein lock arrangement (8) contains extra handle (16) on saloon side along with cab side handle and both handles are interconnected which eliminates the emergency access window opening which will results fire prevention from passenger side to cab side. Special hinge (9) having one leaf with less width (19) which will allow the intumescent strips (10) to expands with increase in temperature due to fire and prevents the fire passing from passenger area to driver cab area.