FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF INVENTION
An electro-pneumatic reverser for traction control
APPLICANTS :
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli,
Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR (S):
Pandya Ankit, Tiwari Laukush and Upadhyay Amarendra of Crompton , Greaves Limited, Machines (M7) Division, D-5 industrial Area, MPAKVN, Mandideep, 462046, Madhya Pradesh, India; all Indian Nationals
PREAMBLE TO THE DESCRIPTION:
The following specification particularly describes the nature of this invention and the manner in which it is to be performed:

Field of the Invention:
This invention relates to the field of traction control Systems.
Particularly, this invention relates to an electro pneumatic reverser for traction control.
Background of the Invention:
A Reverser is used for reversal of current in traction, control system Motor Group Switch Cubical (MSGC) used for reversal of current in traction motor control
Electro Pneumatic (E.P.) Reverser is used to change the direction of field current of Traction Motor, thus changing the direction of the coach / bogie to whose wheels it is attached. It includes a 4-Pole off-load switch, which carries rated current during its operation. It has two sets of Magnet valves; one each for forward and reverse operation. Magnet valves are provided for controlling air for actuation of the reverser. One magnet valve is placed on one side for actuating forward movement. Another magnet valve is placed on other side for actuating reverse movement. It has 4 power contacts and 4 auxiliary contacts (change over type), When forward coil is energised, all 4 power contacts and 4 auxiliary contacts operate & make connection in forward direction. similarly reverse connection is made when reverse coil is energised. This reverser is, typically placed below a train bogie.

During track maintenance of MSGC, it is not possible, due to accessibility problems, to carry out maintenance of magnet valves on the proximal end of the reverser i.e. it is not possible to reach the reverser from all sides and all directions. Even if it possible to reach, it will be appreciated that a lot of time and energy is spent in doing so.
Hence, there is a need for a reverser with easy-to-reach magnet valves.
Objects of the Invention:
An object of the invention is to provide a reverser which is easy to maintain.
Another object of the invention is to provide a reverser which provides for easy access to a person performing maintenance on the magnet valves of the reverser.
Yet another object of the invention is to provide easy-to-access magnet valves on a reverser for maintenance purpose of EP Reverser.
Still another object of the invention is to eliminate the need for dismantling the EP Reverser from the motor switch group cubicle mounted on the bogie of the railway locomotives, for purposes of maintenance.
An additional advantage of the invention is to reduce the amount of time required for replacing the faulty or damaged magnet valves of a reverser.

Yet an additional embodiment of this invention is to provide a reverser that will help in reducing the air leakage problems frequently observed in the operation of EP Reverser.
Summary of the Invention:
According to this invention, there is provided a reverser which comprises:
a. housing characterised with an inner wall located inside said housing, along
the length of said housing, spaced apart from the lateral walls of said
housing, but substantially close to one of said walls, thereby forming an
inner channel;
b. piston and diaphragm mechanism upon which air entering the housing is
thrust in order to move said piston in a first direction if air enters through a
first side and is thrust upon a first diaphragm and to move said piston in a
second direction if air enters through a second side and is thrust upon a
second diaphragm, said piston movement further adapted to engage a rack
and pinion arrangement for movement of a shaft external to the reverser,
characterised in that, said diaphragm is a substantially D-shaped plate having
a curved surface and a linear surface, said curved surface being away from
said inner wall and touching the other lateral wall of said housing, said linear
surface touching said inner wall of said housing;
c. first (forward) magnet valve adapted to control passage of air for actuation
in a forward direction, said first magnet valve being in direct communication
with interior of said housing, said passed air thrust upon a first, near-end,
diaphragm for forward actuation; and

d. second (reverse) magnet valve adapted to control passage of air for actuation in a reverse direction, said second magnet valve being in direct communication with said inner channel in the interior of said housing, said passed air being adapted to be thrust upon a second, far-end, diaphragm for reverse actuation.
Typically, said reverser is an electro-pneumatic reverser.
Typically, said housing includes an air inlet hole on the later wall adjacent said inner wall for input of air from said second (reverse) magnet valve.
Typically, a wheeled assembly is connected to said reverser.
Typically, said housing is a substantially cylindrical housing.
Typically, said diaphragm and piston arrangement is an elongate dumbbell shaped assembly.
Typically, said rack protrudes orthogonally upwards from said piston, which rack in turn, engages a complementary pinion collinear to said rack.
Brief Description of the Accompanying Drawings:
Figure 1 illustrates a schematic reverser of the prior art;

Figure 2a illustrates constructional details of cylindrical case of existing type of EP reverser;
Figure 2b illustrates internal constructional details of cylindrical case of existing type of EP reverser; and
Figure 3 illustrates operational details of existing type of EP reverser.
The invention will now be described in relation to the accompanying drawings, in
which:
Figure 4a illustrates constructional details of cylindrical case of EP reverser;
Figure 4b illustrates internal constructional details of cylindrical case of EP reverser; and
Figures 5 and 6 illustrate operational details of EP reverser.
Detailed Description of the Accompanying Drawings
Figure 1 illustrates a reverser (100) of the prior art. Reference numeral 12 refers to a magnet valve on the anterior side. Reference numeral 14 refers to a magnet valve on the posterior side.
Figure 2a illustrates constructional details of cylindrical case of existing type of EP reverser.

Figure 2b illustrates internal constructional details of cylindrical case of existing
type of EP reverser.
Figure 3 illustrates operational details of existing type of EP reverser.
E.P. Reverser consisted of a main frame that served the basic purpose of housing all the other components of the reverser. Along with this, it also included a hollow portion at one of its ends that acted as a cylinder for the piston (22) and diaphragm arrangement (24) as shown in the Figures 2(b) and 3 of the accompanying drawings. There were two magnet valves (27, 29) attached to the cylinder (26) that controlled the air supply to the two portions of the cylinder (26). These magnet valves (27, 29) were electrically operated and allow the passage of air as and when given the necessary electrical signal. The reverser (100) also uses rack (21) and pinion (23) arrangement to manually change the direction of the reverser (100) using a handle.
As the name suggests, the electro-pneumatic reverser operate on dual supply of electrical signal of 110 V dc along with pneumatic pressure of 4.5 - 7 kg/cm2. As is shown in the figures 1-4 of the accompanying drawings, when electrical supply is given to magnet valve (Forward) (27), it allows the air to pass through it and fill the cylindrical chamber (26) to which it is attached. As the pressure builds up in the chamber (26), it inflates the diaphragm (24) which applies a force on it and finally pushing the piston (22) outwards. As the piston (22) is attached to a rack (21) and pinion arrangement (23), the linear motion of the piston (22) is finally converted to rotational motion of the main shaft on which the main contacts are attached. The rotational motion of the main shaft is used to change over the direction in the reverser. Similarly, when the direction is to be reversed the

electrical signal is fed to the magnet valve (Reverse) (29) and the supply to the magnet valve (Forward) (27) is cut off. Now, the magnet valve (Reverse) (29) allows the passage of air through it and the air passage through magnet valve (Forward) (27) is blocked. As the pneumatic pressure builds in the cylindrical chamber (26) to which the magnet valve (Reverse) (29) is attached, the diaphragm (24) starts inflating and finally moving the piston (22) outwards and as explained earlier the linear motion of the piston (22) is converted to rotational motion of the main shaft. The magnet valves (27, 29) are in sets of two, located on either side of the cylindrical chamber (26), thus providing 4 valves. Each set is connected by an air pipe (not shown).
Reference numeral 31 (Figure 3) refers to an air inlet hole for the magnet valve (forwards (27) which air inlet hole is in direct communication with the interior of the cylindrical chamber (26).
There are certain disadvantages of the system (100), which were highlighted by the many railway loco-sheds where these E.P. Reverser (100) were operational. The major disadvantage of is the inaccessibility of one of the magnet valves in its mounted position in the bogie. As can be seen in the figures of the prior art, the magnet valve which is mounted on the back side is almost invisible and is inaccessible due to the present type of cylinder. Due to the inaccessibility of the magnet valves, the whole of the EP Reverser needs to be dismounted from the motor switch group cubicle that is mounted on the underside of a bogie of a locomotive / train. This whole process takes a lot of time and is very inconvenient for just the maintenance or replacement of a magnet valve. The second disadvantage of the system is that the chances of air leakage is more as the magnet

valves are connected through an air pipe (not shown) and the opening of the pipe gets loose at the terminating points at the magnet valves after certain period of operation.
According to this invention, there is envisaged a reverser (200).
Figure 4a illustrates constructional details of cylindrical case of EP reverser. Figure 4b illustrates internal constructional details of cylindrical case of EP reverser.
Figures 5 and 6 illustrate operational details of EP reverser.
In accordance with an embodiment of this invention, there is envisaged an assembly of magnet valves in a modified cylinder housing such that they are located on one side of the reverser.
In accordance with an embodiment of this invention, there is provided a housing (42) with an air inlet hole (44). There is provided an inner wall (46) located inside the housing, along the length of the housing, spaced apart from the lateral walls of the housing, but substantially close to one of the walls.
In accordance with another embodiment of this invention, there is provided a piston (22) and diaphragm (45) mechanism upon which air entering the housing is thrust in order to engage the rack (21) and pinion (22) arrangement for movement of a shaft or a wheeled assembly connected to the reverser. The diaphragm (45) is a substantially D-shaped plate such that there is a curved surface (45b) and a linear

surface (47a). The curved surface (45b) is away from the inner wall (46) and touches the other lateral wall of the cylindrical chamber (42). The linear surface (47a) touches the inner wall of the cylindrical chamber (42). The diaphragm (45) and piston (22) arrangement resembles an elongate dumbbell shaped assembly. As air hits the diaphragm (45), it moves the piston (22) axially, thereby effecting lateral movement in the rack (21) protruding orthogonally upwards from the piston (22), which in turn, engages a complementary pinion (23). The movement of the pinion (23) is converted to a rotary motion of associated wheels of a wheeled assembly connected to the reverser (200) to effect action. If the movement of the piston (22) is in a first direction actuated by a diaphragm (45) which is actuated by air released in effect from the magnet valve (forward) (45), the reverser (200) is adapted to work in a forward mode, thereby causing a forward action of an associated wheeled assembly. If the movement of the piston is in a second direction actuated by a diaphragm (45) which is actuated by air released in effect from the magnet valve (reverse) (49), the reverser (200) is adapted to work in a reverse mode, thereby causing a reverse action of an associated wheeled assembly.
In accordance with another embodiment of this invention, there is provided a magnet valve (forward) (47) adapted to pass air for actuation in a forward direction. This magnet valve (forward) (47) is in direct communication with the interior of the housing, and air allowed to pass in the housing by the actuation of this magnet valve (forward) (47) directly engaged the piston (22) and diaphragm (45) mechanism for forward actuation.
In accordance with another embodiment of this invention, there is provided a magnet valve (reverse) (49) adapted to pass air for actuation in a reverse direction.

This magnet valve (reverse) (49) is in direct communication with channel defined by the inner wall (46) and the wall of the housing, and air allowed to pass in the housing by the actuation of this magnet valve (reverse) (49) moves along the length of the housing in the channel and effects onto a far end diaphragm which directly engages the piston (22) for reverse actuation. The movement of this air is shown by arrows (51).
This modified cylinder is able to tackle both of the above mentioned problems. The air entry for the magnet valve (forward) (47) remains as it was in the design of the prior art, while the air entry for the magnet valve (reverse) (49) is as shown in figures 4(a), 7, and 9 of the accompanying drawings.
As the air entry is from the same side, the magnet valves will be connected to one side only (distal or proximal) and hence both of them will be easily accessible during maintenance. Also, the pipe connecting the magnet valves is removed in this type of cylindrical arrangement and hence, the problem of air leakage shall also be eliminated.
On track, maintenance of the magnet valves will be possible, with ease.
While this detailed description has disclosed certain specific embodiments of the present invention for illustrative purposes, various modifications will be apparent to those skilled in the art which do not constitute departures from the spirit and scope of the invention as defined in the following claims, and it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

We claim,
1. A reverser comprising:
a. housing characterised with an inner wall located inside said housing, along
the length of said housing, spaced apart from the lateral walls of said
housing, but substantially close to one of said walls, thereby forming an
inner channel;
b. piston and diaphragm mechanism upon which air entering the housing is
thrust in order to move said piston in a first direction if air enters through a
first side and is thrust upon a first diaphragm and to move said piston in a
second direction if air enters through a second side and is thrust upon a
second diaphragm, said piston movement further adapted to engage a rack
and pinion arrangement for movement of a shaft external to the reverser,
characterised in that, said diaphragm is a substantially D-shaped plate having
a curved surface and a linear surface, said curved surface being away from
said inner wall and touching the other lateral wall of said housing, said linear
surface touching said inner wall of said housing;
c. first (forward) magnet valve adapted to control passage of air for actuation
in a forward direction, said first magnet valve being in direct communication
with interior of said housing, said passed air thrust upon a first, near-end,
diaphragm for forward actuation; and
d. second (reverse) magnet valve adapted to control passage of air for actuation
in a reverse direction, said second magnet valve being in direct
communication with said inner channel in the interior of said housing, said
passed air being adapted to be thrust upon a second, far-end, diaphragm for
reverse actuation.

2. A reverser as claimed in claim 1 wherein, said reverser is an electro-pneumatic reverser.
3. A reverser as claimed in claim 1 wherein, said housing includes an air inlet hole on the later wall adjacent said inner wall for input of air from said second (reverse) magnet valve.
4. A reverser as claimed in claim 1 wherein, a wheeled assembly is connected to said reverser.
5. A reverser as claimed in claim 1 wherein, said housing is a substantially cylindrical housing.
6. A reverser as claimed in claim 1 wherein, said diaphragm and piston arrangement is an elongate dumbbell shaped assembly.
7. A reverser as claimed in claim 1 wherein, said rack protrudes orthogonally upwards from said piston, which rack in turn, engages a complementary pinion collinear to said rack.