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
Spring-loaded and graded arcing horn assembly
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; all 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 over voltage/ surge protection systems and systems for safety of electric equipments.
Particularly, this invention relates to commutation in DC Motors.
More particularly, this invention relates to a spring-loaded and graded arcing horn assembly.
Background of the Invention:
Arcing horns or arc-horns are projecting conductors used to protect insulators on high voltage electric power transmission systems from damage during flashover. In motors, the occurrence of high voltages, power surges, or the like high aberrant voltage amplitudes may cause arcs across insulators (flashovers) that can damage them.
It is typically used is in brush gear assembly of traction motors.
Arcing horns are fitted in pairs; one on the transmission side and one on the conducting side. In the event of a flashover, the arcing horns conduct the over voltage by breaking down the air between the arcing horns, thereby causing the overvoltage to be conducted from the transmission side over to the conducting side and ground therefrom.

Arcing horns function by bypassing the high voltage across the insulator using air as a conductive medium. The small gap between the horns ensures that the air between them breaks down resulting in a flashover and conducts the voltage surge rather than cause damage to the insulator. A distance is maintained between the pair of arcing horns which is the aerial discharge gap or the gap required for the transmission arcing horn to cross over to mate with the conducting arcing horn. Arcing horns form a spark gap across the insulator with a lower breakdown voltage than the air path along the insulator surface, so an overvoltage will cause the air to break down and the arc to form between the arcing horns, diverting it away from the surface of the insulator. The geometry of some designs encourages the arc to migrate away from the insulator, driven by rising currents as it heats the surrounding air.
After the discharge of the overvoltage, it is observed that the tip or the entire arcing horn is damaged. The horn needs to be instantaneously replaced in order to secure the safety of the associated switchgear or motor or electrical component.
Prior Art:
According to the existing art, a locking stud-type of arcing horns is used wherein the arcing horn is threaded to a plate.
The locking stud-type of arcing horns has a limited life span and their affectivity keeps on deteriorating under the running condition of the motor. Once the arcing horns have been damaged, there is no protection for the commutator from the flashovers and the life of commutator is reduced.

US 1485127 discloses am Arcing means for brush holders. It provides a brush holder of such construction or provided with means whereby any resultant arcs will be conducted away from the insulators whereby the brush holders are usually maintained in place.
JP63304536 discloses a vertically aligned tension insulator device. It is aimed to prevent the deterioration of the withstand voltage characteristic by providing main arc horns on an upper insulator and auxiliary arc horns around the insulator and fitting auxiliary arc horns with tip sections bent in the direction to avert the upper insulator to a lower insulator.
JP2008218257 discloses an angle adjusting device of arc horn mounting bracket, and angle adjustment method of arc horn mounting bracket. It provides a device and a method for adjusting an angle of an arc horn mounting bracket capable of always securing proper aerial discharge gap between both arc horns by maintaining a state that a first arc horn and a second arc horn linearly oppose to each other even if a strain clamp for supporting both ends of a hanging part of a jumper wire is rotated in the horizontal direction on the lateral side of a steel tower.
There is a need for an assembly which provides greater protection and lesser maintenance.
Objects of the Invention:
An object of the invention is to provide an arcing horn assembly which provides multiple backups.

Another object of the invention is to provide a safer electrical component which requires installation of arcing horns.
Yet another object of the invention is to have an arcing horn installed electrical component having an enhanced life.
Still another object of the invention is to have an arcing horn installed electrical component which requires reduced continuous health monitoring.
Summary of the Invention:
According to this invention, there is provided a spring-loaded cascaded arcing horns assembly, said assembly comprises:
a. a plurality of arcing horns connected one after another in series to form a
protruding cascaded arcing horn assembly;
b. a first bar adapted to locate said plurality of cascaded arcing horns in a parallel
fashion, said arcing horns extending outwards from said first bar;
c. a second bar placed posterior to said first bar, said second bar longer than said
first bar and adapted to guide movement of said first bar;
d. tensioned spring, extending from a portion of an electrical component, adapted
to hold said first bar in a first position so as to make a first cascaded arcing
horn collinear with a conducting side arcing horn and further adapted to
position the bar in order to position each of consecutive cascaded arcing horns
collinear with said conducting side arcing horn upon releasing the tension from
said spring;

e. locking studs at each of said cascaded arcing horn adapted to lock position said
first bar with respect to said second bar for accurate collinear positioning of
each of said cascaded arcing horns consecutively with said conducting side
arcing horn; and
f. stopper adapted to achieve a locking position of said first bar with respect to
said second bar.
Typically, wherein said first bar is an angular bar.
Typically, wherein said second bar is an angular bar.
Typically, wherein said locking studs are screws.
Typically, wherein said tensioned springs are tensioned spiral springs.
Brief Description of the Accompanying Drawings:
Figure 1 illustrates a schematic of the conventional arcing horn arrangement.
The invention will now be described in relation to the accompanying drawings, in which:
Figure 2a illustrates a schematic of the rear view of the spring-loaded arcing horns;
Figure 2b illustrates a schematic of the side view of the spring-loaded arcing horns;

Figure 3 a illustrates a schematic of the side view of the spring-loaded graded arcing horns;
Figure 3 b illustrates a schematic of the rear view of a portion of the spring-loaded graded arcing horns;
Figure 4 illustrates a rear view of the schematic of the spring-loaded cascaded / graded arcing horns; and
Figure 5 illustrates an isometric view of the schematic of the spring-loaded cascaded / graded arcing horns.
Detailed Description of the Accompanying Drawings:
Figure 1 illustrates a schematic of the conventional arcing horn arrangement.
Reference numeral 10 relates to a transmission side arcing horn and reference numeral 12 refers to a conducting side arcing horn. Reference numeral 14 relates to the air gap between the transmission side arcing horn 10 and the conducting side arcing horn 14. In the event of a surge or flashover, the transmission side arcing horn crosses over the air gap and mates with the conducting side arcing horn , thereby providing a discharge (earthing) path to the surge, through the conducting side.
According to this invention, there is provided spring-loaded cascaded arcing horns.
Figure 2a illustrates a schematic of the rear view of the spring-loaded arcing horns.

Figure 2b illustrates a schematic of the side view of the spring-loaded arcing horns. Figure 3a illustrates a schematic of the side view of the spring-loaded graded arcing horns. Figure 3 b illustrates a schematic of the rear view of a portion of the spring-loaded graded arcing horns.
Figure 4 illustrates a rear view of the schematic of the spring-loaded cascaded / graded arcing horns. Figure 5 illustrates an isometric view of the schematic of the spring-loaded cascaded / graded arcing horns.
In accordance with an embodiment of this invention, there is provided a plurality of arcing horns (22, 24, 26) connected in series to form a cascaded / graded arcing horn assembly (32). In the event of a flashover, these transmission side arcing horns cross over to the conducting horns wherein a first arcing horn (22) makes contact with the conducting horn. There is a possibility of a burnout which may cause the first arcing horn due burnout. In this case, the second arcing horn (24) automatically provides a backup transmission side arcing horn. Further, after the burnout of the second arcing horn, a third arcing horn (26) may be utilized in the event of a surge, thereby providing multiple backups without needing continuous monitoring or interruption or change.
In accordance with another embodiment of this invention, there is provided a first bar (30) adapted to locate a plurality of cascaded arcing horns (32, 34, 36) parallely. A second bar (38) is placed posterior to said first bar (30). Each of the arcing horns is locked onto the bar by means of locking studs (42, 44, 46). Typically, the first bar (30) is attached to a portion of the electrical component (48) upon which it is installed by means of a tensioned spring (40). A stopper (50)

prevents the first bar to remain in a required position. The required position is such that the first cascaded arcing horn (32) is collinear with the transmission side arcing horn. As one cascaded arcing horn (32) is fully deteriorated or reached burnout, a locking stud (42) is removed. The tension in the spring (40) moves the first bar (30) towards the stopper (50) which also aligns the cascaded transmission side arcing horn with the conducting side arcing horn. Further, as locking studs (44) and (46) are removed, the further conducting side arcing horns (34) and (36) are aligned in front of the conducting side arcing horn.
Thus, as shown in the figure, a 9-array of arcing horns are provided.
The present invention reduces flash over rate. It also increases life of the electrical component using said invention. It also lowers maintenance requirement.
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 spring-loaded cascaded arcing horns assembly, said assembly comprising:
a. a plurality of arcing horns connected one after another in series to form a
protruding cascaded arcing horn assembly;
b. a first bar adapted to locate said plurality of cascaded arcing horns in a
parallel fashion, said arcing horns extending outwards from said first bar;
c. a second bar placed posterior to said first bar, said second bar longer than
said first bar and adapted to guide movement of said first bar;
d. tensioned spring, extending from a portion of an electrical component,
adapted to hold said first bar in a first position so as to make a first cascaded
arcing horn collinear with a conducting side arcing horn and further adapted
to position the bar in order to position each of consecutive cascaded arcing
horns collinear with said conducting side arcing horn upon releasing the
tension from said spring;
e. locking studs at each of said cascaded arcing horn adapted to lock position
said first bar with respect to said second bar for accurate collinear
positioning of each of said cascaded arcing horns consecutively with said
conducting side arcing horn; and
f. stopper adapted to achieve a locking position of said first bar with respect to
said second bar.
2. An assembly as claimed in claim 1, wherein said first bar is an angular bar.
3. An assembly as claimed in claim 1, wherein said second bar is an angular bar.
4. An assembly as claimed in claim 1, wherein said locking studs are screws.

5. An assembly as claimed in claim 1, wherein said tensioned springs are tensioned spiral springs.