FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
AND
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
A universal mounting fixture for axle counter sensors.
APPLICANT(S)
Crompton Greaves Limited, CG House, 6th Floor, Dr. Annie Besant Road, Worli, Mumbai - 400030, Maharashtra, India; an Indian Company.
INVENTOR(S)
Shukla Mayank, George Roshan, Kamble Deepak and Mahajan Ramakant, all of Crompton Greaves Limited, CG Global R&D Centre, Aryabhatta Building, Kanjur Marg (E), Mumbai-400042, Maharashtra, 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 electronics engineering and processing systems.
Particularly, this invention relates to a signaling system for railways.
Specifically, this invention relates to axle counters for railways.
More specifically, this invention relates to a universal mounting fixture for axle counter sensors.
BACKGROUND OF THE INVENTION
Railways and rail transport are an important way of terrestrial travel and form a large network of railroads or railway tracks laid throughout a country for long-distance travel or a defined jurisdiction for relatively short-distance or even urban travel. With increasing population, dependency on railroad travel is increasing and traffic on railroads is getting dense.
In order to monitor and rationalize such traffic, on a railway network, newer and newer systems are being tried, tested, and deployed in order to squeeze in more trains per hour without comprising on safety. According to standard safety regulations, there is a pre-defined gap in terms of signaling sections that is to be followed in between two consecutive trains on a given linear line or even at crossings. This incorporates a signaling system on the tracks which is centrally guided or controlled in order to notify a train driver of impending danger or to allow the driver to continue, hindrance-free. Thus, every train driver, by way of signals on the railway track, needs to know that there is a defined vacant space between the driver's train and a train which is up-forward so that the speed can be controlled to that degree which the space allows so as to avoid running into one another and causing a collision.
There are sensors which sense a train passage over a defined segment of a track. One of such sensors is an axle-counting sensor. An axle counter is a device on a railway that detects the passing of a train instead of the more common track circuit. The safety and accident-free operation of the railway depends crucially on the proper function of the axle counting and train

detection systems. Therefore, there are provided multiple axle-counters communicably couple to each other by means of a modem on a single track section.
A counting head is installed at each end of the section, and as each axle passes the head at the start of the section, a counter mechanism increments its count value. A detection point comprises two independent sensors; therefore, the device can detect the direction of a train by the order in which the sensors are passed. As the train passes a similar counting head at the end of the section, the counter mechanism decrements its count value. If the net count is evaluated as zero, the section is presumed to be clear for a second train.
A fixture is required to mount these sensors on railway track. Currently, there are fixed types of mounting sensors with freedom of movement restricted to a single axis. Fixed type fixture for mounting sensors on the railway track with freedom of movement restricted to single axis limiting the field of electromagnetic field generated or developed by the transmitting antenna. But there are several disadvantages with this fixed type of fixture i.e. Non compatibility with different Rail profiles (52kg/60kg/90lbs) and also fixed position of sensors cripples the possibility of increase or decrease of electromagnetic strength. This may result in erroneous readings or result in custom fit designs of axle counter fixtures for the sensors.
PRIOR ART
US4912406 and US8109474 disclose imparting degrees of freedom for magnets and sensors. CN102338160 also discloses a five-degree-of-freedom magnetic bearing. CN102305242 also discloses a radial-axial three-degree-of-freedom alternating current-direct current hybrid magnetic bearing. GB512191 and US2011127389 discloses slidable adjustments to an axle counter. However, sensors, in axle counters, having degrees of freedom, per se, are not disclosed. Further, specifically, fixtures of mounting arrangements, or devices which enable various degrees of freedom is not specifically disclosed.
The prior art document CN2583624 discloses a sliding rail device of a magnetic displacement sensor, which is composed of a fixed ruler frame and a movable ruler body. This imparts movement to the sensor. The frictional resistance of reciprocating straight-line motion of single

degree of freedom is decreased to a smaller extent, and the accuracy of the straight-line motion of the single degree of freedom of the sliding rail device is enhanced. However, it doesn't disclose anything about freedom of movement of sensors and hence there will be decrease in electromagnetic strength.
The prior art document CA2685575 discloses an invention which uses time, space, and wheel diversity in measurement of each axle. This system, further, uses sensors on both rails separated by an optimum distance so as to contain an entire bogie therein. However, there is no dynamic degree of freedom movement imparted to the sensors.
The prior art document US4912406 discloses a magnet having been positioned such that there is at least one degree of freedom. Although specific 3-degrees of freedom are not disclosed, the claim mentions at least 1-degree of freedom. It mainly describes about contactless position measurer for ferromagnetic components has variable reluctance magnetic circuit with pivoted magnet in housing with synchro-resolver of angular displacement. However, its applications in axle counters, having sensors with degrees of freedom, is not disclosed.
The prior art document GB512191 discloses a device which is slidably adjustable on a bracket clamped to the rail base. The device may be used to count the axles of the trains passing a block length of rail, in order to be sure that in effect all trucks pass the controlled or supervised length of rail. However, multiple degrees of freedom of movement are not disclosed.
The prior art document US2011127389 discloses a device which has mounting arrangement such that there is 1-degree of freedom for the sensors. The detector comprises a mounting system that ' can be utilized between traditional rail ties and concrete ties and can be adapted for three different size running rail heights. The detector can be placed below a running rail top height with low profile housing, which is not higher than height of the running rail, so as to allow for an easy fit on or beside any track without causing obstruction to any object such as the train. However, multiple degrees of freedom of movement are not disclosed.
The prior art document US5133521 discloses a detectors for identifying railroad wheels having flat sectors caused by skidding resulting from the emergency application of brakes, for example,

and particularly to stationary detector systems for installation in transit system storage yards and railroad classification yards by which all wheels of every passing train may be monitored and flat wheels identified for replacement. However, multiple degrees of freedom of movement are not disclosed.
The prior art document US6371417 relates to monitoring railway trains, and in particular to a method and apparatus used to detect the presence, speed and direction of railway trains, and to count their wheels, and measure their wheel radius and wheel flange depth. The system also provides for detection of faults in the signal processor and sensory circuit about 30 times per second, using closed loop feedback paths from every major component. However, multiple degrees of freedom of movement are not disclosed.
Hence, there is a need for a universal design for a fixture for mounting sensors such that there are multiple degrees of freedom which allow for the fixture to work efficiently with any railway track size by merely adjusting the components of the fixture, mechanically.
OBJECTS OF THE INVENTION
An object of the invention is to provide a universal design for sensors for axle counters.
Another object of the invention is to provide a universal design for sensors for axle counter which provides three degrees of freedom of movement.
Yet another object of the invention is to provide adjustment of sensors in an axle counter fixture in various ways, with respect to its position near the tracks.
Still another object of the invention is to provide adjustment of sensors in an axle counter fixture to fit the exact rail profile of the section.
An additional object of the invention is to provide adjustment of sensors in an axle counter to provide variation of electromagnetic field, thereby giving a control of the functioning of the sensor with respect to various wheel profiles and any wear and tear on the track.

Yet an additional object of the invention is to provide single design for axle counters to be used across any rail profiles and under any type of rail traffic.
Still an additional object of the invention is to provide an axle counter fixture design to control the flux linkage between the transmitter coil and receiver coil of a sensor, by adjusting placement the coils with respect to each other.
Another additional object of the invention is to provide an axle counter fixture design to adjust the spacing between the two sets of sensors (transmitter and receiver coils), by adjusting placement of sensors with respect to each other.
Yet another additional object of the invention is to provide an axle counter fixture design which accounts for varying sizes of wheels by providing sensor and coil placement adjustments with respect to each other.
Still another additional object of the invention is to provide effective coupling between a pair of transmitter and receiver which forms one sensor in an axle counter fixture design.
Another object of the invention is to provide an axle counter fixture design with reduced crosstalk between adjacent sensors.
SUMMARY OF THE INVENTION
According to this invention, there is provided a universal mounting fixture for axle-counter sensors, said fixture comprises:
a. at least a longitudinal bar adapted to provide a support structure for said fixture when said
fixture is aligned alongside rails;
b. at least a transverse bar adapted to intersect said longitudinal bar;
c. at least a resting bracket spaced apart from said at least a longitudinal bar;
d. at least a sensor housing held by said resting bracket in order to hold at least a sensor to
sense wheels for determining axle count, said at least a resting bracket being provisioned

on a slidable mechanism on said at least a transverse bar in order to provide for an operative horizontal linear motion on said transverse bar for determining the spaced apart distance of the resting bracket with respect to said longitudinal bar, thereby imparting a first degree of freedom to said fixture in terms of an operative horizontal linear motion of said at least a resting bracket on said at least a transverse bar;
e. at least a plate angularly displaceable on an operative inner side of said upper vertical
member of the resting bracket, said angularly displaceable plate abutting said at least a
sensor housing to said at least a resting bracket, thereby making said at least a sensor
housing to be angularly displaceable, thereby imparting a second degree of freedom to
said fixture in terms of a roll motion of said at least a sensor housing with respect to the
ground; and
f. at least a slidable mechanism on an outer side of said sensor housing in order to work
with said at least a plate in order to provide for an operative vertical-linear motion to said
at least a sensor housing with respect to said rail and said at least a resting bracket for
determining the spaced apart distance of said at least a sensor housing and sensor,
thereof, with respect to said a least a transverse bar and rail height, thereof, thereby
imparting a third degree of freedom to said fixture in terms of an operative vertical linear
motion of said at least a sensor housing and sensor, thereof.
Typically, said at least a resting bracket is an L-shaped bracket, with its lower horizontal arm resting on said transverse bar and its upper vertical bar being orthogonal to said transverse bar.
Typically, said at least a sensor is an electromagnetic sensor.
Typically, said at least a transverse bar is a mounting mechanism for said fixture with respect to the ground adjacent said rails.
Typically, said at least a sensor is a cylindrical magnetic sensor.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The invention will now be described in relation to the accompanying drawings, in which:

Figure 1 illustrates an isometric view of a portion of the universal mounting fixture for axle counter sensors;
Figures 2 and 3 illustrate isometric views of a portion of the universal mounting fixture for axle counter sensors, where the sensor housing is angularly displaced;
Figure 4 illustrates a top view of a railway track along with installations of the universal mounting fixture for axle counter sensors;
Figure 5 illustrates a sectional view of a railway track along with sensors that have been angularly displaced due to the universal mounting fixture for axle counter sensors;
Figure 6 illustrates a top view a complete universal mounting fixture for axle counter sensors along with a railway track;
Figure 7 illustrates an isometric view a complete universal mounting fixture for axle counter sensors along with a railway track; and
Figure 8 illustrates a side view a complete universal mounting fixture for axle counter sensors along with a railway track.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
According to this invention, there is provided a universal mounting fixture for axle counter sensors.
Figure 1 illustrates an isometric view of a portion of the universal mounting fixture (100) for axle counter sensors.
Figures 2 and 3 illustrate isometric views of a portion of the universal mounting fixture (100) for axle counter sensors, where the sensor housing is angularly displaced.

In accordance with an embodiment of this invention, there is provided a longitudinal bar (12) adapted to provide a support structure for the fixture when the fixture is aligned alongside the rails (10) of a railway track. This longitudinal bar, typically, runs parallel to the railway track, abuts adjacent the tracks, and provides support and acts as a resting member of the fixture. The longitudinal bar functions as a mounting mechanism for the fixture with respect to the rails.
In accordance with another embodiment of this invention, there is provided at least one transverse bar (14) adapted to intersect said longitudinal bar. Typically, the at least one transverse bar comprises a resting bracket (16) spaced apart from the longitudinal bar. The resting bracket, typically, is an L-shaped bracket, with its lower horizontal arm resting on the transverse bar and the upper vertical bar being orthogonal to the transverse bar. The resting bracket is adapted to hold at least a sensor housing (18) in order to hold a sensor to sense wheels for determining axle count. Typically, the sensor is an electromagnetic sensor. Typically, the resting bracket is provisioned on a slidable mechanism (22) on the transverse bar in order to provide for an operative horizontal linear motion on the transverse bar. This determines the spaced apart distance of the resting bracket with respect to the longitudinal bar. This operative horizontal linear motion of the resting bracket imparts a first degree of freedom to the universal mounting fixture for axle counter sensors. The transverse bar functions as a mounting mechanism for the fixture with respect to the ground adjacent the rails.
Typically, the sensor is a cylindrical magnetic sensor, i.e., the sensor comprises a cylindrical shaped core. This keeps the inductance value at an optimum level for a range of frequency, so as to keep the magnetic coupling to a desirably high value, but at the same time ensure that the core inherent core losses are kept to a minimum. Furthermore, the use of this type of sensor reduces size of axle counter, imparts flexibility in sensor positioning enabling the regularization of flux linkage, provides concentrated magnetic field, and minimizes cross talk between the sensors functioning at different frequencies as the inductance value of the coil is tuned for that particular operating frequency.
In accordance with yet another embodiment of this invention, there is provided a plate (24) angularly displaceable on the operative inner side of the upper vertical member of the resting

bracket. The angularly displaceable plate abuts the sensor housing to the resting bracket. Thus, the sensor housing becomes angularly displaceable providing it a roll motion. This angular displacement motion of the sensor housing imparts a second degree of freedom to the universal mounting fixture for axle counter sensors.
Typically, the sensor housing (18) is provided with a slidable mechanism (26) on its outer side in order to work with a protrusion of the plate in order to provide for an operative vertical linear motion with respect to the rail and the resting bracket. This determines the spaced apart distance of the sensor housing and sensor, thereof, with respect to the transverse bar and rail height, thereof This operative vertical linear motion of the sensor housing and sensor, thereof, imparts a third degree of freedom to the universal mounting fixture for axle counter sensors.
Figure 4 illustrates a top view of a railway track along with installations of the universal mounting fixture for axle counter sensors.
Figure 5 illustrates a sectional view of a railway track along with sensors that have been angularly displaced due to the universal mounting fixture for axle counter sensors.
Figure 6 illustrates a top view a complete universal mounting fixture for axle counter sensors along with a railway track.
Figure 7 illustrates an isometric view a complete universal mounting fixture for axle counter sensors along with a railway track.
Figure 8 illustrates a side view a complete universal mounting fixture for axle counter sensors along with a railway track.
With the use of this fixture, the angle of sensors can be adjusted; both individually (as seen in Figure 5 of the accompanying drawings) as well as with other sensors in the fixture in order to fit the exact rail profile of the section where the fixture is being mounted. Also, with the angular movement capability, variations of electromagnetic field is obtained thereby giving a control of

the functioning of the sensor with respect to various wheel profiles and any wear and tear on the track.
Electromagnetic sensors are mounted on the rail track at a defined angle (transmitter sensor on the outer web and the receiver sensor on the inner web). The sensor is ferrite core with windings and transmits voltage at 60V p-p ac.
These sensors are connected to the track side equipment, typically, via 2 core shielded cables (2.5 sqmm) of length 10 m.
Cables are connected to the track side device through MS box type ALLIED connectors.
The similar set up is replicated at another end of the rail section which together integrates to form the Axle counter setup. The distance of a particular section can vary, typically, from 1km to v 20km.
The two sections are again linked with each other, typically, by 4 core shielded cables (2.5sqmm) and the communication is through leased line modem.
In the absence of a train wheel, the transmitted signal is received by the receiving sensor at the same frequency and phase. Typically, the amplitude varies from 150 mV to 200 mV. As per RDSO standards, the presence of a wheel over the sensor is determined by a change in phase of the receiving signal by 180°C and attenuation in voltage level between 20% and 80% of the original received signal. This received signal is further processed to obtain digital output which facilitates the counting algorithm. The processed digital signal should be clean without any glitches or multiple pulses for a single rail wheel detected.
The inventive step of this invention lies in the construction and mechanical features of the universal design of the fixture or mounting arrangement or device with mounts sensors to assume various positions and allows for different degrees of freedom of movement. These sensors are used specifically for axle counters. Their ability to move in the at least 3-degrees of freedom (up-down movement (Y-axis); left-right movement (Z-axis); and angular displacement or roll

movement) provides for dynamic placement of the sensors in order to sense various wheel sizes, and hence, various bogie / wagon sizes of a train. The claimed advantages or providing degree of freedom to the sensors includes:
a. to control the flux linkage between the transmitter coil and receiver coil of a sensor, by
adjusting placement the coils with respect to each other;
b. to adjust the spacing between the two sets of sensors (transmitter and receiver coils), by
adjusting placement of sensors with respect to each other; and
c. to account for varying sizes of wheels by providing sensor and coil placement adjustments
with respect to each other.
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 universal mounting fixture for axle-counter sensors, said fixture comprising:
a. at least a longitudinal bar adapted to provide a support structure for said fixture
when said fixture is aligned alongside rails;
b. at least a transverse bar adapted to intersect said longitudinal bar;
c. at least a resting bracket spaced apart from said at least a longitudinal bar;
d. at least a sensor housing held by said resting bracket in order to hold at least a
sensor to sense wheels for determining axle count, said at least a resting bracket
being provisioned on a slidable mechanism on said at least a transverse bar in
order to provide for an operative horizontal linear motion on said transverse bar
for determining the spaced apart distance of the resting bracket with respect to
said longitudinal bar, thereby imparting a first degree of freedom to said fixture in
terms of an operative horizontal linear motion of said at least a resting bracket on
said at least a transverse bar;
e. at least a plate angularly displaceable on an operative inner side of said upper
vertical member of the resting bracket, said angularly displaceable plate abutting
said at least a sensor housing to said at least a resting bracket, thereby making said
at least a sensor housing to be angularly displaceable, thereby imparting a second
degree of freedom to said fixture in terms of a roll motion of said at least a sensor
housing with respect to the ground; and
f. at least a slidable mechanism on an outer side of said sensor housing in order to
work with said at least a plate in order to provide for an operative vertical linear
motion to said at least a sensor housing with respect to said rail and said at least a
resting bracket for determining the spaced apart distance of said at least a sensor
housing and sensor, thereof, with respect to said a least a transverse bar and rail
height, thereof, thereby imparting a third degree of freedom to said fixture in
terms of an operative vertical linear motion of said at least a sensor housing and
sensor, thereof.

2. The universal mounting fixture for axle-counter sensors as claimed in claim 1, wherein said at least a resting bracket is an L-shaped bracket, with its lower horizontal arm resting on said transverse bar and its upper vertical bar being orthogonal to said transverse bar.
3. The universal mounting fixture for axle-counter sensors as claimed in claim 1, wherein said at least a sensor is an electromagnetic sensor.
4. The universal mounting fixture for axle-counter sensors as claimed in claim 1, wherein said at least a transverse bar is a mounting mechanism for said fixture with respect to the ground adjacent said rails.
5. The universal mounting fixture for axle-counter sensors as claimed in claim 1, wherein said at least a sensor is a cylindrical magnetic sensor.