FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See section 10, rule 13)
1. Title of the invention: VISUAL WEAR INDICATOR FOR NEUTRAL SECTION
ASSEMBLY
2. Applicant(s)
NAME NATIONALITY ADDRESS
RAYCHEM RPG PVT. LTD Indian 463, Dr Annie Besant Road, Worli, Mumbai, Maharashtra, 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.

TECHNICAL FIELD
[0001] The present subject matter relates, in general, to overhead line
equipments. More specifically, the present subject matter relates to a neutral section assembly for isolating or separating different sections of the overhead electricity transmission line for railways.
BACKGROUND
[0002] A neutral section is a portion of the overhead electricity
transmission line which acts as insulated phase separating various sections of the overhead line connected to two or more adjacent substations. In general, an electric train engine or electric locomotive may receive electrical power from the overhead lines in which adjacent sections of the overhead line are powered by different substations. It may be noted that, to provide equal loading on all phases of the generated electric power, each substation supplies corresponding section with different phase. The neutral section uses insulators for providing insulation and smooth transition between adjacent contact wire sections. The insulators are made of insulating material like Engineering polymer, such as polytetrafluoroethylene (PTFE) based rollers or rods, which may degenerate or wears with passage of time and need routine maintenance or replacement.
BRIEF DESCRIPTION OF DRAWINGS
[0003] The features, aspects, and advantages of the present subject
matter will be better understood with regards to the following description and accompanying figures. The use of the same reference number in different figures indicate similar or identical features and components.
[0004] FIG. 1A provides a schematic of an electricity transmission
environment having an overhead electricity transmission line feeding an electric locomotive, in accordance with an embodiment of the present subject matter;

[0005] FIGS. 1B and 1C illustrate isometric views of a portion of a
neutral section assembly comprising plurality of rotatable members from two different angles, wherein the rotatable member is a roller, in accordance with an embodiment of the present subject matter;
[0006] FIGS. 1D, 1E and 1F illustrate a top view, a side view and an
isometric view, respectively, of a portion of a neutral section assembly
comprising plurality of rotatable members, wherein the rotatable member is
a rod, in accordance with an embodiment of the present subject matter;
[0007] FIGS. 2A-2B illustrate an isometric view and front view,
respectively, of a rotatable member to provide a wear indication for a neutral section assembly, in accordance with an embodiment of the present subject matter;
[0008] FIGS. 3A-3C illustrate an isometric view, front view and cross-
sectional view, respectively, of an outer body of the rotatable member, in accordance with an embodiment of the present subject matter;
[0009] FIGS. 4A and 4B illustrate an isometric view and cross-sectional
view, respectively, of an inner body of a rotatable member comprising a light reflecting strip, in accordance with an embodiment of the present subject matter;
[0010] FIG. 5 illustrates cross-sectional view of a rotatable member
comprising the inner body having a light reflecting strip, in accordance with an embodiment of the present subject matter;
[0011] FIG. 6 illustrates a cross-sectional view of a rotatable member
having an outer body and an inner body made of different materials,
according to an example implementation of the present subject matter;
[0012] FIGS. 7A and 7B illustrate an isometric view and cross-sectional
view, respectively, of the inner body of the rotatable member having the outer body and the inner body made of different materials, in accordance with an embodiment of the present subject matter; and
[0013] FIGS. 8A, 8B and 8C illustrate an isometric view, front view and
cross-sectional view, respectively, of the rotatable member having a

diameter substantially less than a length, in accordance with an embodiment of the present subject matter.
[0014] It may be noted that throughout the drawings, identical
reference numbers designate similar, but not necessarily identical, elements. The figures are not necessarily to scale, and the size of some parts may be exaggerated to more clearly illustrate the example shown. Moreover, the drawings provide examples and/or implementations consistent with the description; however, the description is not limited to the examples and/or implementations provided in the drawings.
DETAILED DESCRIPTION
[0015] As may be understood, with rapid development of high-speed
railways, electrification of the railway network is being carried on at a rapid pace to increase passenger comfort and to reduce operational cost of the railway network. Overhead electricity transmission network or overhead lines are utilized to feed the electric locomotive or other type of electric vehicle used in railways. Such overhead line equipment includes various important parts, one of which is the contact wire which carries the electricity to be supplied to the electric locomotive through a current collecting device known as pantograph. The pantograph is a metallic antenna placed on the carriage of the electric locomotives which is in a close contact with the overhead contact wire and draws the propagating electricity through the contact wire.
[0016] In general, the contact wire of the overhead line equipment is
supplied by a feeder station. As may be generally understood, the feeder station may be a facility next to National Grid electricity transmission line that extracts 25kV and transmits it to the overhead line of the railway via several transmission lines. Due to the wide expansion of the railway network, it is not possible for a single feeder station to feed whole railway lines. Thus, a number of feeder stations are placed with a predefined

spacing, such as at every 30-40 km, which maintain average 25kV in the contact wire at each instant of time.
[0017] Generally, the feed provided by such feeder stations is out of
phase with each other so as to provide equal loading on each of the phase of the generated electrical energy. Such change in phase of input power may inadvertently affect the operationality of electric locomotive and may even damage numerous electrical components of the train and the network as well. To avoid such circumstances, neutral sections are deployed. Neutral sections are dead zones in the overhead line, used to isolate sections overhead line equipment OHE for smooth transition from one phase to another and switching from one substation or feeder station to another.
[0018] The neutral sections constitute an electrically insulated or non-
conducting element positioned between sections of the contact wire and fitting overhead catenary wire with insulators. Such neutral sections use rollers or rods, generally made of engineering polymers such as polytetrafluoroethylene (PTFE), as an insulator for providing isolation between adjacent overhead line equipment sections which comprise of contact and catenary wires. As the locomotive passes, the pantograph may be dragged across the rollers or rods which, over a period of time, may result in wearing down of these rollers or rods. Such wearing of rollers or rods may result in exposing of underlying FRP which need to be immediately relaced for smooth operation. . Further, exposure of underlying FRP inside the rollers or rods to drastic and continually changing environmental conditions may result into erosion and even breakage, in some instances.
[0019] Such wearing down of rods or rollers leads to extensive
maintenance and replacement cycle for the neutral section, e.g., around every 3-4 months for rods and 12-15 months for rollers respectively. Rollers or rods are generally circular in cross section. It is to be noted that after having a given depth of wear during the operation, the rods need to be rotated. A rod can be rotated maximum of five times during a life cycle of

the rod. Manual intervention is required each time to rotate the rod, which
also requires a shutdown of OHE line. Whereas, the rollers rotate on its own
and need only one final replacement through the life cycle. After a number
of cycles of pantograph movement along surface of the rollers or rods, the
surface of the rollers or rods starts wearing down or gets flattened.
[0020] Depending on the frequency of movement of pantograph, an
amount of wear of engineering polymers based rods or rollers is periodically inspected manually. Devices, such as Vernier calipers are used to evaluate the amount of wear of the rollers or rods due to multiple passes of pantograph. Thus, periodic manual intervention is required to check physical dimensions of rods or rollers to evaluate the amount of wear of the rods or rollers depending on the reduction in diameter of the rods or rollers. After a predetermined amount of wear, rollers or rods needs to be replaced with a new rod or rollers. However, it is time intensive to evaluate the wear of the rollers or rods by measuring dimensions such as diameter through manual inspections and also complete shutdown of the line is required for the same. Moreover, measuring the amount of wear of each roller is a cumbersome task.
[0021] To this end, the present subject matter provides an automated/
self-energized and efficient technique for providing a visual indication of wear of a rotatable member such as roller or rod of a neutral section assembly.
[0022] Examples of a rotatable member to provide a wear indication
for a neutral section assembly, are described. In an embodiment, the
rotatable member overcomes the above-described problems associated
with the conventional manual methods available for evaluating an amount
of wear of a rotatable member of a neutral section assembly as a result of
movement of a pantograph along the neutral section assembly.
[0023] The rotatable member includes an outer body and an inner
body. The outer body comprises a hollow portion and the inner body is accommodated within the hollow portion of the outer body. In an example

embodiment, the inner body comprises a visual indicator. The visual indicator indicates a predetermined level of wear of the outer body of the rotatable member encountered as a result of movement of a pantograph along the neutral section assembly.
[0024] In an example, the rotatable member act as an insulator of the
neutral section assembly that electrically isolates two adjacent contact wire sections of an overhead transmission line. When the pantograph moves along the neutral section assembly, surface of the rotatable member gets wear down. When a predetermined level of wear of the outer body is encountered, the visual indicator on the inner body starts to become visible through the outer body thereby indicating that the rotatable member is wear out and needs to be replaced or requires maintenance. In an example, the predetermined level of wear may be substantially equal to a thickness of the outer body. This visual indicator on the inner body obviates the need of periodic manual inspection for evaluating the amount of wear of the rotatable member of the neutral section assembly which is a cumbersome task and requires complete shutdown of the line.
[0025] The above and other features, aspects, and advantages of the
subject matter will be better explained with regard to the following description and accompanying figures. It should be noted that the description and figures merely illustrate the principles of the present subject matter along with examples described herein and should not be construed as a limitation to the present subject matter. It is thus understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting principles, aspects, and examples thereof, are intended to encompass equivalents thereof. Further, for the sake of simplicity, and without limitation, the same numbers are used throughout the drawings to reference like features and components.
[0026] FIG. 1 illustrates an electricity transmission environment 100
involving an overhead electricity transmission line 102 (referred to as

overhead line 102) for transmitting electrical energy to an electric locomotive 104, according to an example of the present subject matter. The overhead line 102 is positioned at a certain height above the railway track using mast posts, and corresponding arms. In an example, these mast posts are positioned after a span of 18 to 72m, which may be decided based on the curvature and the structures surrounding the track. In an example, such overhead line 102 is constituted of various components. Examples of such components include, but are not limited to, catenary wire, contact wire, dropper, turnbuckle, and guy wire. The contact wire needs to maintain a constant tension to assure smooth current collection and to have sufficient weight and tension to limit a pantograph 106 uplift. The contact wire is suspended from the catenary wire by using droppers for making a contact with a pantograph 106 placed on the carriage of the electric locomotive 104. The contact wire material comprises, for example, grooved slid copper or copper alloy.
[0027] In an example, the contact wire of the overhead line 102 supply
the required electricity to the electric locomotive 104 running on the railway network via pantograph 106 and other connecting means. The contact wire contains the alternating current of 25kV provided by the numerous feeder station (not shown in the FIG. 1). The feeder station, as mentioned previously, is a facility next to National Grid electricity transmission line that extracts 25kV of electricity and transmits it to the overhead line equipment 102 of the railway via several transmission means. As explained previously, to provide equal load to all the three phases of the electrical energy receiving from feeder station, numerous feeder station with different electric phase are located on equal distance to feed the corresponding contact wire section. It is difficult to lower the pantograph 106 when such junction of contact wire approaches. A neutral section assembly 108 is placed between the adjacent contact wire sections to isolate these sections. In general, neutral section, such as neutral section assembly 108, is positioned in such a manner that it maintains a near distance with a traction sub-station (TSS),

and a sectioning post (SP). Further, neutral section assembly is placed on the levelled tracks to ensure that the train passes through the neutral section without stopping. In an example, the neutral section assembly 108 may isolate a first section 110 of the overhead line from a second section 112 of the overhead line.
[0028] In an example, if neutral section assembly 108, is placed
between the adjacent overhead line sections so as to enable all three phases of the electric supply to be utilized. The neutral section assembly 108 isolates the powered sections of different phases. The neutral section assembly 108 comprises one or more rotatable member (whose constructional details is explained later in conjunction with FIG. 2A-2B, FIG. 3A-3C, FIG. 4A-4B, FIG. 5, FIG. 6, FIG. 7A-7B and 8A-8C) made of insulating Engineering polymer based material such as PTFE. The one or more rotatable member incorporated in the neutral section assembly act as an insulator of the neutral section assembly.
[0029] In an example, while running on the railway track, the electric
locomotive 104 may initially receive appropriate electrical energy via pantograph 106 placed on the roof of the electric locomotive 104 through the contact wire of the first section 110 and appropriately feed its other components. On approaching other end of the first contact wire section 110, the pantograph 106 may transit itself to the neutral section assembly 108 and move along the rotatable member (not shown in Fig.1) incorporated in the neutral section assembly. Thereafter, the pantograph 106 transits from the neutral section assembly 108 to the second contact wire section 112. In this manner, the neutral section assembly 108 provides isolation of the first contact wire section 110 from the second contact wire section 112 while the rotatable member made of insulating material incorporated in the neutral section assembly 108 enable smooth movement of the pantograph along the neutral section assembly 108.
[0030] Further details of the manner in which the rotatable member are
assembled in the neutral section assembly 108 is described in detail in

conjunction with FIGS. 1B-1F. FIG. 1B and 1C illustrates isometric views of a portion 108-1 of a neutral section assembly 108 comprising a plurality of rotatable member from two different angles, wherein the rotatable member is a roller, according to an embodiment of the present subject matter. FIG. 1D, FIG. 1E and FIG. 1F illustrate a top view, a side view and an isometric view, respectively, of a portion 108-1 of a neutral section assembly 108 comprising a plurality of rotatable member, wherein the rotatable member is a rod, according to another embodiment of the present subject matter.
[0031] The rotatable member act as an insulator of a neutral section
assembly 108 and isolates the adjacent sections of the contact wire during movement of the pantograph 106 along the neutral section assembly 108. Further, the rotatable member rotates in relation the movement of the pantograph 106 and gets wear down after multiple cycles of the movement of the pantograph 106. A rotatable member having a visual indicator to indicate an amount wear of the rotatable member is disclosed according to the present subject matter and described below. A neutral section assembly have multiple rotatable member to isolate the adjacent sections of contact wire. However, explanation is provided with respect to one such rotatable member.
[0032] FIG. 2A and 2B illustrate an isometric view and a front view,
respectively, of a rotatable member 200 to provide a wear indication for a neutral section assembly 108, in accordance with an embodiment of the present subject matter. The rotatable member 200 comprises an outer body 202 and an inner body 204. In an example, the rotatable member 200 may be substantially cylindrical in shape. The rotatable member 200 is made of an insulating material. In another example, the outer body 202 and the inner body may be made of the same or different materials.
[0033] In an example, a diameter of the rotatable member 200 is
substantially same as a length of the rotatable member 200. In such a case, the rotatable member 200 can be considered as a roller.

[0034] In another example, a diameter of the rotatable member 200 is
substantially smaller than a length of the rotatable member 200. In such a case, the rotatable member 200 can be considered as a rod.
[0035] FIG. 3A illustrates an isometric view of the outer body 202.
FIG.3B illustrates front view of the outer body 202. FIG. 3C illustrates a cross-sectional view of the outer body 202 along a section B-B as indicated in FIG. 3B. In an example, the outer body 202 of the rotatable member 200 comprises a hollow portion and the inner body 204 is accommodated within the hollow portion of the outer body 202. In an example, the inner body 204 and the outer body 202 are joined through a threaded joint. In an example, the inner body 204 is a hollow cylindrical body. In an example, the inner body 204 comprises a visual indicator. With each movement of the pantograph 106 along the neutral section assembly 108, the outer body 202 encounters some wear such as reduction in thickness. After a certain number of movements of the pantograph, the outer body 202 attains a threshold level of wear. At this stage, the visual indicator of the inner body starts to become visible through the outer body. The visual indicator of the inner body 204 indicates a predetermined level of wear of the outer body 202 of the rotatable member 200 encountered as a result of movement of the pantograph 106 along the neutral section assembly 108. The predetermined level of wear may be a reduction in a diameter of the rotatable member 200.
[0036] In an example, the outer body 202 and the inner body are made
of similar insulating engineering polymer material, such as fluoro polymer. In an example, the fluoro polymer is PTFE and the outer body 202 and inner body 204 are made of PTFE material. In an example, the inner body 204 and the outer body 202 are made of a material comprising Fluoro Polymers in 60-80% v/v & semi crystalline engineering thermoplastic in 20%-40% v/v. In addition to this, for improvement of mechanical and insulating property of the rotatable member 200 some additives may be incorporated as per the requirements. Further, the coefficient of friction of two fluoro polymer layers

are very low, which even at extremely heat due to rigorous operations such as frequent/ multiple pantograph movement, will keep the wear rate at minimum.
[0037] In such an example, where the inner and outer bodies 202, 204
are made of similar insulating material, the visual indicator comprises at least one light reflecting strip 206 along a circumference of the inner body 204. FIG. 4A illustrates an isometric view of the inner body 204 of the comprising the light reflecting strip 206. FIG. 4B illustrates a cross-sectional view of the inner body 204 of the 200 comprising the light reflecting strip 206 along a cross section C-C as mentioned in FIG. 4A. Further, FIG. 5 illustrates cross-sectional view of a rotatable member 200 comprising the inner body 204 having the light reflecting strip 206 along a section A-A as mentioned in FIG. 2B. The light reflecting strip 206 becomes visible through the outer body 202 when the predetermined level of wear of outer body 202 is encountered. For example, if the diameter of the rotatable member 200 gets reduced from 32 mm to 29 mm or the thickness of the outer body 202 gets reduced from 5 mm to 2 mm, the light reflecting strip 206 over the inner body 204 becomes visible through the outer body 202. Thus, an automatic visual indication of the predetermined level of wear of the rotatable member 200 is provided and a need of frequent manual inspection to evaluate the amount of wear of the rotatable member is obviated.
[0038] In an example implementation of the present subject matter, the
inner body 204 and the outer body 202 are made of different insulating engineering polymer materials. In such an example, where the inner and outer bodies 202, 204 are made of different materials, to provide a wear indication, the visual indicator comprises the inner body 204 being made of a polymer material having a color different than the color of a polymer material of the outer body 202. In an example, the inner body 204 can be made of a polymer material having dark or bright color. While the outer body 202 may be made of a polymer material having a light color and become translucent on thickness of the outer body 202 becoming less. In this case,

the color of the inner body 204 becomes visible through the outer body 202 when the predetermined level of wear of the outer body 202 is encountered as the result of movement of the pantograph 106 along the neutral section assembly 108.
[0039] In an example, the inner body 204 is made of a material
comprising Fluoro Polymers in a range of 60-80% v/v and semi crystalline engineering thermoplastic in a range of 20%-40% v/v. In an example, the outer body 202 is made of a fluoro polymer. In an example, the fluoro polymer is PTFE. FIG. 6 illustrates a cross-sectional view of a rotatable member 200 having an outer body and an inner body made of different materials, according to an example implementation of the present subject matter. FIG. 7A illustrates an isometric view of an inner body of the rotatable member having an outer body and the inner body made of different materials. FIG. 7B illustrates a cross-sectional view of the inner body of the rotatable member having an outer body and the inner body made of different materials along a section D-D as mentioned in FIG. 7A.
[0040] In an example implementation, FIGS. 8A, 8B and-8C illustrate
an isometric view, front view and cross-sectional view, respectively, of the rotatable member 200 having a diameter substantially less than its length. Figure 8C illustrates the cross-sectional view of the rotatable member 200 along a section E-E as indicated in FIG. 8B. In such cases, the inner body 204 may be made of a fibre-reinforced plastic material. The visual wear indicator may comprise a layer 206 of the material comprising Fluoro Polymers in a range of 60-80% v/v and semi crystalline engineering thermoplastic in a range of 20%-40% v/v formed over the inner body 204. The outer body 202 may be made of a Fluoro Polymer. The color of the outer body 202 is different than a color of the layer 206 formed on the inner body 204. The color of the layer 206 may be fluorescent in nature and the color of the material of the outer body 202 may be light, such that when outer body 202 attains a predetermined level of wear, the layer 206 of

fluorescent color formed over the inner body 204 becomes visible through outer body 202.
[0041] As mentioned above, a neutral section assembly can include a
plurality of rotatable members to isolate adjacent sections of a contact wire. Referring back to FIG. 1B and 1C, each of the plurality of rotatable members 200 incorporated in the portion 108-1 of the neutral section assembly 108 has a diameter substantially same as its length. That is, in the embodiment depicted in FIG. 1B and 1C, the plurality of rotatable members 200 are rollers. Whereas, each of the plurality of rotatable members 200 incorporated in the portion 108-1 of the neutral section assembly 108 as illustrated in FIG. 1D-1F has a diameter substantially less than its length. That is, in the example embodiment depicted in FIG. 1D-1F, the plurality of rotatable members are rods.
[0042] Thus, various configurations of the rotatable members are
possible wherein the diameter and length of the rotatable members are in different proportions to each other. The visual indicator on the outer body 202 of each of the plurality of rotatable members 200 automatically indicates that the rotatable member has encountered a predetermined amount of wear and needs maintenance or replacement.
[0043] Although examples for the present disclosure have been
described in language specific to structural features, it is to be understood that the appended claims are not necessarily limited to the specific features described in the specification. Rather, the specific features are disclosed and explained as examples of the present disclosure.

I/We claim:
1. A rotatable member 200 to provide a wear indication for a neutral
section assembly 108, wherein the rotatable member 200 comprises:
an outer body 202, the outer body 202 comprising a hollow portion;
an inner body 204 to be accommodated within the hollow portion;
wherein the inner body 204 comprises a visual indicator to indicate a predetermined level of wear of the outer body 202 of the rotatable member 200 encountered as a result of movement of a pantograph 106 along the neutral section assembly 108.
2. The rotatable member 200 as claimed in claim 1, wherein the inner body 204 and the outer body 202 are made of similar insulating engineering polymer material.
3. The rotatable member 200 as claimed in claim 2, wherein the inner body 204 and the outer body 202 are made of a material comprising Fluoro Polymers in 60-80% v/v & semi crystalline engineering thermoplastic in 20%-40% v/v.
4. The rotatable member 200 as claimed in claim 2, wherein the inner body 204 and the outer body 202 are made of PTFE.
5. The rotatable member 200 as claimed in anyone of claims 2 to 4, wherein the visual indicator comprises at least one light reflecting strip 206 along a circumference of the inner body 204, the light reflecting strip 206 being visible through the outer body 202 when the predetermined level of wear of outer body 202 is encountered.

6. The rotatable member 200 as claimed in claim 1, wherein the inner body 204 and the outer body 202 are made of different insulating engineering polymer materials.
7. The rotatable member 200 as claimed in claim 5, wherein the visual indicator comprises the inner body 204 being made of a polymer material having a color different than the color of a polymer material of the outer body 202, the color of the inner body 204 being visible through the outer body 202 when the predetermined level of wear of outer body 202 is encountered.
8. The rotatable member 200 as claimed in claim 6 or claim 7, wherein the inner roller body 204 is made of a material comprising Fluoro Polymers in a range of 60-80% v/v and semi crystalline engineering thermoplastic in a range of 20%-40% v/v, and wherein the outer roller body 202 is made of Fluoro Polymer.
9. The rotatable member 200 as claimed in claim 1, wherein a diameter of the rotatable member 200 is substantially smaller than a length of the rotatable member.
10. The rotatable member 200 as claimed in anyone of claims 6 to 9, wherein the inner body is made of a fibre-reinforced plastic material and wherein the visual indicator comprises a layer of the material comprising Fluoro Polymers in a range of 60-80% v/v and semi crystalline engineering thermoplastic in a range of 20%-40% v/v formed over the inner body, and wherein the outer roller body 202 is made of a Fluoro Polymer.
11. The rotatable member 200 as claimed in claim 1, wherein a diameter of the rotatable member is substantially same as a length of the rotatable member.

12. The rotatable member 200 as claimed in claim 1, wherein the inner body 204 and the outer body 202 are joined through a threaded joint.
13. The rotatable member 200 as claimed in claim 1, wherein the rotatable member 200 act as an insulator of the neutral section assembly 108 and rotates in relation to the movement of the pantograph 106 along the neutral section assembly 108.