TECHNICAL FIELD OF THE INVENTION

The present subject matter described herein, relates to a clamp based axle detector. It particularly relates to a clamp based axle detector that can be clamped with the base of the rail in railway networks.

BACKGROUND OF THE INVENTION

An axle counter is a device on a railway that detects the passing of a train between two points on a track. There are known devices in the art for such detection of passing of the trains for detecting occupancy of railway track section primarily for the vital control of section occupancy of the railway track.

In the year 2002, Central Electronics Limited (CEL) has designed and developed a device, Single Section Digital Axle Counter (SSDAC) for use in Indian railways. SSDAC detects the presence of the train between two points in a straight line by the principle of axle counting. SSDAC is adapted to count the axles of the train by use of axle detectors. These axle detectors consist of the transmitter (TX) and receiver (RX) coils tuned for frequencies 21 KHz and 23 KHz. The coils are connected with trackside electronic unit of a railway network using copper wire of 10m length. These axle detectors are fitted to the web of the rail using 12” nuts and bolts. The web of the rail has to be drilled with three holes for mounting of the housing of TX and RX coils of the axle detectors.

Currently there are three types of rail profiles in the Indian Railways viz. 44Kg, 52 Kg and 60 Kg. The height of the rail web varies as per the rail profiles. The axle detectors are supplied with marking jig and accordingly holes are marked. Using suitable drill bit size, three holes are drilled and track devices are mounted on the rail web. However, the drilling of holes at different places in the rail web results in weakening of the rail, which may eventually result in the rail fracture.

Reference is made to ‘Argenia Solar + Wireless Digital Axle counting system’ which is a microprocessor controlled digitizing railway wheel sensor system for urban rail, mainline and train yard applications. This system is having adjustable mounting bracket which does not require drilling of the rail. However, it is having movable parts, which in turn has the possibility of hampering its function.

Reference is made to ‘Axle Counter by Large Marketing Group Infotech’ which can be easily clamped to the base of the rail without the need to drill holes through the rail. But this axle counter is having the sensors that are based on the mounting of sensors from one side of the system.

Reference is made to ‘Axle Counter Az LM’, which is Thales’ flagship system for train detection in any application that discloses wheel sensor available with clamp mounting to mount the wheel sensor without drilling, which leads to short installation and removal times. Although, this clamp appears to be quite sleek, but it however takes relatively large surface area on the rail.

Reference is made to the literature ‘State-of-the-Art Wheel Detection and Axle Counting Systems’, Gerhard Grundnig, for Frauscher Sensor Technology that discloses about various axle counting system by Fraushcer such as ‘Frauscher Axle Counting System ACS2000’ (link:https://www.unece.org/fileadmin/DAM/trans/main/temtermp/2012_2nd_Expert_Group_Meeting_Ankara/TEM_March_2012_frauscher_showcase_ankara.pdf, last accessed March 15, 2019). The features of the devices mentioned in the cited art are having flexible positioning, easy and quick mounting or dismounting, proven and efficient solution for every possible requirement and also requires no drilling of rail. For instance ‘Frauscher Axle Counting System ACS2000’ is having wheel sensors that are mounted on one of the running rails easily, quickly and without the need for drilling, using rail claws. This reduces the time spent by personnel in a hazardous area to a minimum. It discloses clamp based axle detectors that work on different technology having sensors on the single side of the rail. However, it does not disclose about axle detectors and clamp that has been designed to be fixed from the centre having transmitter and receiver on both side of the rail to work exclusive with 21 KHz and 23 KHz frequency respectively.

Therefore hitherto there is a dire need to provide a clamp based axle detector that requires no drilling for installation, is easy to install, requires less maintenance, is reliable and is also cost effective.

SUMMARY OF THE INVENTION

The following disclosure presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later.

An object of the present invention is to provide a clamp based axle detector that requires no drilling for installation.

Another object of the present invention is to provide a clamp based axle detector that has been designed to be fixed from the centre having transmitter and receiver on both side of the rail.

Yet another object of the present invention is to provide a clamp based axle detector having easy Installation and less maintenance.

Another object of the present invention is to provide a clamp based axle detector that can be adjusted for various rail profiles.

Yet another object of the present invention is to provide a clamp based axle detector in which the clamps are fitted on the base of the rail and to prevent all chances of mis-fitting.

Accordingly, in one aspect, the present invention discloses a clamp based axle detector device comprising a housing. The housing comprises the clamp, wherein the clamp is fixed from the center of said housing, and an axle detector coil, wherein the clamp and the axle detector coil are mechanically coupled with each other. The axle detector coil connects to a rail web through the clamp.

In one aspect, in one implementation, in the axle detector device, the clamp comprises of at least two angle of inclinations (?1, ?2) according to the inclination of the rail web.

In one aspect, in one implementation, in the axle detector device, the inclination angle ?1 vary from 15° to 20° and said inclination angle ?2 vary from 8° to 12°.

In one aspect, in one implementation, in the axle detector device, the materials for manufacturing the clamp is at least one selected from cast iron, stainless steel, other grades of mild steel and fiber glass (Reinforced -Polymer) IRS: 510.

In one aspect, in one implementation, in the axle detector device, the axle detector coil comprises at least one transmitter (Tx) coil and at least one receiver (Rx) coil.

In one aspect, in one implementation, in the axle detector device, the coils and are mounted on the rail web through the clamp.

Briefly, various aspects of the subject matter described herein are directed at a clamp based axle detectors in which the axle detectors and clamp have been designed to be fixed from the centre having transmitter (TX) and receiver (RX) on both side of the rail. The TX and RX work exclusively with frequencies 21 KHz and 23 KHz. The invention involves the design of two main components: (i) Axle detectors and (ii) Clamp for axle detectors.

Other salient features and advantages of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings in which:

Figure 1 illustrates the axle detector clamp as per an embodiment of the present invention.

Figure 2 illustrates the axle detector coil as per an embodiment of the present invention.

Figure 3 illustrates the RX coil as per an embodiment of the present invention.

Figure 4 illustrates TX coil as per an embodiment of the present invention.

Figure 5 illustrates the block diagram of the assembly sequence of clamp, RX coil, TX coil and rail web as per an embodiment of the present invention.

Figure 5 illustrates the assembly sequence of clamp, RX coil, TX coil and rail web as per an embodiment of the present invention.

Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure. Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary.

Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

The terms and words used in the following description are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by their equivalents.

It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

By the term “substantially” wherever used or will be used later it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments.

It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

In an embodiment of the present invention is disclosed a clamp based axle detector, the design of which is having two main components, the said components being: (i) Axle detectors and (ii) Clamp for axle detectors.

The axle detectors comprises of housing. The housing has been preferably design using FRP material. The axle detector housing is having the provision of being mounted from centre using nuts and bolts. Preferably, two nuts of 12 mm each and bolts each of length 60 mm have been used.

The axle detectors comprises of TX having 21 KHz and 23 KHz coils tuned for 21 KHz and 23 kHz frequency. These signals are excited from the electronic circuit which is connected with this axle detector using cable. The length of the cable is preferably 10 m. The oscillator circuit operates at 24 VDC and generates the oscillating voltage of 37 Vrms of frequency 21 KHz and 23 KHz.

Further, the Axle Detectors comprises of RX housing having RX coils that is mounted on the inner side of the rail and is adapted to be positioned opposite to the TX coils. The RX coil receives 21 KHz and 23 KHz signals from independent coil and receives the signal of around 300 milli volts. These signals received by the RX coil are then sent to a trackside electronic circuit and converted into pulses.

As per the present invention, during a ‘no wheel’ condition of the section of the rail, the phase angle of TX coil is in 180 degrees out of the phase with TX coil. When train wheel passes through the TX and RX coil, it cuts the flux. Due to this movement of the wheel, the phase difference of the RX signal comes in phase with the TX signal. T he thus obtained change in phase is detected and processed by the electronic circuit card in the trackside electronics unit.

The clamp of the clamp based axle detector has been developed preferably by using mild steel and it has been further fabricated. The clamp of TX and RX coils is same. Two clamps are preferably used to mount one TX and RX housing for a single trackside electronics unit.

Figure 1 shows an exemplary embodiment of clamp based axle detector, AD CLAMP (9). Figure 1 illustrates a through hole (1) is used to mount the AD CLAMP on the rail web with the help of bolt (8). Figure 2 shows the exemplary embodiment of the axle detector coil (10). Figures 1 and 2 illustrate that coil (10) and AD CLAMP (9) are both coupled with each other by means of bolts (6, 7). The first bolt (6) is used in a sliding slot (3) and the second bolt (7) is used in a hole at (2). Further the AD CLAMP (9) comprises of two inclinations (4 and 5). The angles of inclination (?1, ?2) of the inclination of the AD CLAMP (9) are according to the inclination of rail web.

The inclination angle ?1 may vary from 15° to 20° and the angle ?2 may vary from 8° to 12°. The height (y) of AD CLAMP varies from 78 mm to 105 mm. The materials preferred to be used for designing AD CLAMP (9) are cast iron, stainless steel, other various grades of mild steel and fiber glass (Reinforced -Polymer) IRS: 510.

Figure 3 discloses the exemplary embodiment of the RX coil (10R). It has shown two Aluminum foil at positions marked as position ‘a’ and also at position ‘b’. Two holes (c) are used to mount the RX coil on the AD CLAMP (9). Each of the holes having a diameter, d is used for wire connection. There are other sixteen holes (e) used to mount the cover on the coil after the housing is filled with potting compound. This compound restricts ingress of water inside the housing. The material of TX coil (10 T) is preferably fibre glass (Reinforced Polymer) IRS: 510 and glass reinforced. The RX coil (10 T) is connected in inner side of the rail web (11).

Figure 4 discloses the exemplary embodiment of the TX coil (10T) as per the present invention. The eight holes (e) are used or mount the cover on the coil. Two holes (d) are used for wire connection and another two holes (c) are used to mount the TX coil (10T) on the AD CLAMP (9). The material for making the RX coil (10R) is preferably Fiber glass (Reinforced - Polymer) IRS: 510 and glass reinforced. The TX coil (10 T) is always connected in outer side of the rail web (11).

Herein above, the various parts of the clamp based axle detector as per the present invention have been explained. Figure 5 shows the block diagram of the assembly sequence of AD CLAMP (9), RX coil (10R), TX coil (10T) and rail web (11). The coils 10R and 10T are mounted on the rail web (11) through AD CLAMP (9). Further in figure 6 shows the proper assembly of AD CLAMP (9), Axle detector coil (10) and the Rail web (11). The axle detector coil (10) connects to rail web (11) with help of AD CLAMP (9), as is depicted in the figure 6. The Axle Detector as per the present invention works with standard cable length of up to 15 meters and is suitable of fixing with various rail types from 52 Kg to 71 Kg being used in railways.

The clamps of the axle detectors are fitted on the base of the rail and therefore there is no chance of mis-fitting it on to the rail. The axle detectors of the present invention can be adjusted for various rail profiles by use of spacers such as nylon spacers. This feature can also be used for addressing the issues due to wear and tear.

Some of the noteworthy features of the present invention are mentioned below:
1. The invention requires no drilling of the rail web for its mounting. The axle detectors of the present invention can be mounted on the web of the rail without making holes on the rail web. The track directorate of Indian Railways maintains the rails and is having the opinion that drilling holes at various parts results in the weakening of the rail and causes rail fracture. This issue has been addressed by the present invention.
2. The clamp based axle detectors help railways to fix these axle detectors without the drilling of the holes. The present invention makes the installation and maintenance simpler. The present invention facilitates for signal maintainer to reinstall these axle detectors after regular rail change by track directorate. Thus, the present invention is having easy installation and less maintenance.
3. As per the prior art, the axle detectors are required to be reinstalled using fresh holes. In the present invention, it can be adjusted by use of nylon spacers as per the requirement. Therefore they can be added or removed to cover the effect of wear and tear of rails.
4. The present invention assists for correct functioning of the system. The clamps are fitted on the base of the rail and therefore the chance of mis-fitting on to the rail, is eliminated.

WE CLAIM :

1. A clamp based axle detector device comprising a housing having:
said clamp (9), wherein said clamp (9) fixed from the center of said housing;
and an axle detector coil (10), wherein said clamp and said axle detector coil are mechanically coupled with each other;
wherein said axle detector coil (10) connects to a rail web (11) through said clamp (9).

2. The axle detector device as claimed in the claim 1, wherein said clamp (9) comprises of at least two angle of inclinations (?1, ?2) according to the inclination of said rail web.

3. The axle detector device as claimed in the claim 2, wherein said inclination angle ?1 vary from 15° to 20° and said inclination angle ?2 vary from 8° to 12°.

4. The axle detector device as claimed in the claim 1, wherein materials for manufacturing said clamp (9) is at least one selected from cast iron, stainless steel, other grades of mild steel and fiber glass (Reinforced -Polymer) IRS: 510.

5. The axle detector device as claimed in the claim 1, wherein said axle detector coil (10) comprises at least one transmitter (Tx) coil (10T) and at least one receiver (Rx) coil (10R).

6. The axle detector device as claimed in the claim 5, wherein said coils (10R) and (10T) are mounted on said rail web (11) through said clamp (9).