OBJECTIVE OF THE INVENTION
The present invention relates to single link bottom discharge door mechanism for hopper
wagons. The current invention proposes to introduce a quick and reliable bottom
discharge door mechanism with three large single linked doors with 6 large door openings for application on high axle load hopper type wagons on the Indian Railways.
BACKGROUND OF THE INVENTION
Hopper type wagons are currently used extensively in India for the transportation of
Coal, Iron Ore, and other higher bulk density materials. Material is loaded through silo
top loading and unloaded by either a side discharge or a bottom discharge door
mechanism in the wagon. Current bottom discharge door mechanism available in the
hopper type wagons consist of an 8 flap double acting door mechanism with 4 doors and
4 openings (two flaps on each door). Each door in this wagon accounts for covering one
opening under the wagons facilitated by 2 door flaps hinged laterally. With a total of
eight flaps for unloading, it highlights the need for the maintenance of eight door flaps
(with sub components) at regular intervals. The current design is suitable for a 22.9 ton
axle load with a payload of up to 64 tons. This current design supports a freight train
3 configuration of 58 wagons with a net volumetric capacity per wagon of 56.78 m . The
containments of a wagon is offloaded through 4 door openings, each having an opening

area of 0.75 m with a total area of 3 m at a discharge rate of 3.15 m /s (3.34 t/s).

With the advent of the need for higher volumetric capacity of wagons to haul more
material at a given time, a higher axle load wagon with enhanced volumetric capacity is
envisaged. This need essentially calls for a suitable wagon design for transport of
material with a feature to support quick and efficient discharge. The wagon is designed
by increasing small amount of length and decreasing width for this purpose with a higher
volumetric capacity along with a higher axle load bearing capacity. This
invention incorporates an innovative bottom discharge mechanism through
3 large single link doors with 6 openings. This invention proposes a higher discharge

rate of 3.78 m /s (4.01 t/s) with a total door opening area of 5.70 m (0.95 m
for each door). The larger door openings cumulatively support discharge of higher
3 volumetric capacity of 71 m at a rate, higher than the existing door mechanism.
The invention also offers a less complex design of door mechanism as the
operation of this door involves open – close phenomena being performed at
least twice a day.
This invention of the single link bottom discharge door mechanism proposes the
following features over the existing wagon discharge mechanism:

DESCRIPTION Hopper Wagon with Existing Door Hopper Wagon with Proposed Door
Axle Load 22.32 t 25 t
Pay Load 63.67 t 75 t
Gross Load 89.28 t 100 t
Volume 3 56.78 m 3 71 m
Tare Weight 25.61 t 25 t
No of Doors 4 (8 flaps) 3 (3 single)

No of Door openings
Door Opening Area (single) Total Opening Area Discharge Rate

4 6
2 0.75 m 2 0.95 m
2 3 m 2 5.70 m
3 3.15 m /s (3.34 t/s) 3 3.78 m /s (4.01 t/s)

SUMMARY OF THE INVENTION
According to the present invention, there is provided an innovative bottom discharge door operating mechanism that comprises of 3 large single link doors with 6 openings and a higher discharge rate on a hopper type wagon of 25 ton axle load. The said invention consists of 3 large single link door flaps at the bottom of the super structure being hinged on a single side with a configuration of one single link large door covering for two opening spots that account for the higher discharge rate. Each of these door openings is larger in size in comparison to the existing door opening size available in the current bottom discharge wagon. The door operating mechanism essentially is at the bottom of the hopper shaped inside super structure surface that facilitates the discharge of material from the bottom. The single link doors are places at longitudinal intervals at the bottom of the wagon super structure between the two bogies being at distal ends. The single link doors are fitted and hinged along the wagon laterally panning below the Center Sill of the wagon. On either sides of the center sill are the door openings of equal size that is accounted for discharge by a single link door. Three such single link doors thus account for a total of 6 door openings, hence providing for a high discharge rate and a much larger opening at the bottom of the wagon superstructure. This door mechanism shall be operated using a
4

spool valve that will function electro-pneumatically /pneumatically connected by
levers to initiate the door open – close phenomena. The spool valve is compatible with
a manual button operated pneumatic open – close phenomena as well as an electro
pneumatic automatic charged open – close phenomena depending upon the
exact requirement of the customer during operation. This invention essentially
incorporates the large door opening to sustain the high volumetric capacity and higher payload capacity on the wagon.
OBJECT OF THE INVENTION
The main objective of this invention is to provide an innovative bottom discharge door operating mechanism for Indian Railways Hopper type wagon of 25 tonne axle load to suit higher haulage of material and effective quick discharge through large openings at the bottom.
Another objective of this invention is to provide 3 large single links doors accounting for 6 openings for the mechanism in place of the existing 4 doors that accounted for 4 openings. This overall larger opening facilitates quick and effective discharge of material from the wagon.
A still another objective of this invention is to provide with larger door opening as under the wagon superstructure for quicker discharge of more material over existing mechanism accounted by the proposed 6 larger door openings in place of existing 4 door openings. Reduced Cycle times, i.e. Loading and unloading times may accumulate extra revenue of Indian Railways.

Yet another objective of this invention is to provide large single link doors for the bottom discharge mechanism with minimal hinge components, less pneumatic linkages, less total components, and a simpler mechanism over the existing operating bottom door mechanism.
A further objective of this invention is to provide a simpler and energy efficient door operating mechanism that utilizes lower energy for operating 3 door items over the existing mechanism used for operating 8 flaps – 4 door items.
DRAWINGS OF THE INVENTION
New invention Door Closing Condition – Side View Fig. 1
New invention Door Opening Condition – Side View Fig. 2
Proposed Single Link Bottom Discharge Door Mechanism – Full View Fig. 3
Existing Door Mechanism Arrangement (Sheet 01) Fig 4
Existing Door Mechanism Arrangement (Sheet 02) Fig 5
DETAILED DESCRIPTION OF THE INVENTION
The current invention proposes a new innovative bottom discharge door
mechanism on hopper type wagons with a 25 tonne axle load high volume operation goal on the Indian Railways network. This invention incorporates three large single link doors at the bottom of the wagon that pan out laterally along the width of wagon placed at longitudinal intervals between the two distal end bogies

below the wagon super structure. This door mechanism has each single link door
hinged on one side laterally at the bottom of the wagon body that pans out through
the bottom of the center sill covering two door openings. Each door opening
available in the proposed invention is designed significantly larger than existing door
opening size on the current operating bottom discharge wagons to account for the
higher volume of material that shall be hauled in view of the higher load bearing
capacity. A larger door opening assures a quicker discharge rate over the existing
design to ensure quick discharge of the said bulk material. The large door opening on
the invention also assures seamless discharge of a higher volume through a large
door opening over a smaller door opening with bulk material gushing through the
small opening. The existing door mechanism has two flaps at each opening that
release out at the open position. The invention however innovatively incorporates a
single link one side door flap with the other end being fixed with the wagon body super
superstructure. A one side single link flap door essentially assures lower
attention time and maintenance cost therefore promising an efficient and cost
effective maintenance.
The door mechanism is operated by a spool valve that is capable of working through a pneumatic / electro pneumatic mechanism facilitated by air cylinders and pneumatic valves. The mechanism is attached to each of the single link doors through cylinder for effective operation of the open – close phenomena. The door open – close mechanism is triggered from the spool valve through the cylinder

pressure and in turn pulls out the door. At the end of discharge of material, the door
locks in to the close position. A pneumatic spool valve can trigger the open – close
phenomena by manually hitting a button on the valve for opening the door,
discharge, and further closing the doors at the end of discharge. All three doors work simultaneously at the triggering of the spool valve for open and close. An electro pneumatic spool valve is triggered by running a freight wagon on a charged section that electrically charges the valve in its field and opens the door. Further, at the end of discharge, the door goes to its close position.
This single link door mechanism is more efficient over the current existing design as the spool valve, levers, and cylinders are responsible for the operation of three doors in place of four doors in the existing design. Energy utilization of the three single links doors is substantially lower than that of the existing 4 dour configuration and thus the new invention promises Energy efficient operation for the mechanism.
Thus from this revolutionary simple single link Bottom discharge door mechanism for
application on a 25 ton axle load bottom discharge hopper wagon with a high
volume, a high efficiency, cost effective, and quick discharge mechanism is
proposed to support the unloading of high bulk density material at a much quick pace with a very simple design for effective and inexpensive maintenance facilitated by an energy efficient discharge mechanism.

WE CLAIM
1. A new single link bottom discharge door mechanism for hopper wagons for
enhanced volumetric capacity comprising:
a set of 3 single link bottom discharge doors ( 3 ) placed laterally below a wagon super structure spaced longitudinally between the distal end bogies, six large door openings (5) with three on either side of the center sill of the wagon for discharge of material, single side hinged doors ( 3 ) at the bottom, a Spool valve disposed for triggering and transmitting pressure through cylinders ( 1 ) and levers to the doors for the opening and closing phenomena, wherein the whole mechanism being fitted under the wagon superstructure as sprung mass of the wagon.
The single link bottom discharge door mechanism (2) as claimed in claim 1 wherein the mechanism has single link single side hinged doors that are connected laterally along the bottom of the super structure to attain less no of doors.
The single link bottom discharge door mechanism ( 2 ) as claimed in claim 2 wherein the wagon super structure is proposed with 6 numbers of door openings at the bottom of the superstructure with 3 openings on each side of the center sill to provide a large surface area for the discharge of voluminous bulk material.

4. The single link bottom discharge door mechanism ( 2 ) as claimed in claim 1
wherein a spool valve for operating the open – close phenomena is provided and is compatible with pneumatic and electro pneumatic mechanisms.
5. The single link bottom discharge door mechanism ( 2 ) as claimed in claim
1 wherein an energy efficient mechanism is proposed due to the operation
requirement for 3 doors in lieu of existing design with 4 door and 8 flap door
mechanism.