FORM -2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
COMPUTER IMPLEMENTED COUPLING WEAR INDICATOR
Emerson Electric Company
a.U.S Company
of 8000 West Florissant Avenue St. Louis,
Missouri 63136 USA
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE NATURE OF THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

FIELD OF THE INVENTION
The present invention generally relates to couplings.
Particularly, the present invention relates to coupling wear indicators for providing real-time wear magnitude of couplings.
BACKGROUND OF THE INVENTION
A coupling is a device used for connecting two shafts together at their ends for facilitating transmission of power. The main function of a coupling is to join two pieces of rotating equipment while permitting some degree of misalignment or end movement or both. Specifically, couplings are used in machinery for several purposes, such as connection of shafts of units that are manufactured separately such as a motor and generator and to provide for disconnection for repairs or alternations, to reduce the transmission of shock loads from one shaft to another, to alter the vibration characteristics of rotating units, to introduce protection against overloads and the like.
Generally, failure of a coupling leads to failure of the machine/equipment incorporating that coupling. Accordingly, timely maintenance and replacement of coupling is necessary for safety, efficiency and effectivity of the machine / equipment. One of the main reasons for coupling failure is wear. Couplings wear out during usage. Once maximum wear limit, such as 6-8 mm for medium - large coupling is reached, a user should not continue to use these couplings. Presently, for checking wear limit of couplings, notch markings are provided on the coupling. Accordingly, by observing these notch markings, a user is able to monitor the wear situation regularly.

However, this method of monitoring wear by observing notch markings provided on couplings is inconvenient, hard, and comparatively ineffective.
Also disclosed in the prior art is an electro-mechanical mechanism that is adapted to provide signals to a programmable logic controller (PLC) of the machine / equipment when the wear limit is reached. However, even this prior art wear monitoring arrangement is unable to provide real-time wear magnitude of couplings. Further, the prior art wear monitoring arrangement is susceptible to give false wear limit values due to misalignment, sudden jerks and the like. Also, the prior art wear monitoring arrangement needs to be assembled / disassembled as per the loading direction.
Accordingly, there is need for a coupling wear indicator that is adapted to provide real-time wear magnitude of couplings. Further, there is need of a coupling wear indicator that is adapted to provide real-time wear magnitude of couplings based on the average of many cycles and thereby prevent false wear limit signals. Furthermore, there is need for a coupling wear indicator that precludes assembly/ disassembly thereof based on the loading direction. Moreover, there is need for a coupling wear indicator that is simple in construction.
OBJECTS OF THE INVENTION
An object of the present invention is to provide a coupling wear indicator that is adapted to provide real-time wear magnitude of couplings.

Still another object of the invention is to provide a coupling wear indicator that is adapted to provide real-time wear magnitude of couplings based on the average of many cycles and thereby prevent false wear magnitudes.
Yet another object of the present invention is to provide a coupling wear indicator that precludes assembly / disassembly thereof based on loading direction.
Yet another object of the present invention is to provide a coupling wear indicator that is simple in construction.
Another object of the present invention is to provide a coupling wear indicator that is convenient, user friendly and effective.
Still another object of the present invention is to provide a coupling wear indicator that prevents sudden failure of the coupling.
Another object of the present invention is to provide a coupling wear indicator that is easy to install.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, there is provided a computer implemented coupling wear indicator for determining real-time wear magnitude of couplings. The coupling wear indicator includes at least one pair of calibrating pins, a reference pin, sensing means and computational means. In the operative configuration of the indicator, the pair of calibrating pins is adapted to be disposed on a coupling and the reference pin is functionally coupled to the coupling and disposed in between the pair

of calibrating pins at the same / different operative level as the pair of calibrating pins. The sensing means is functionally coupled to the pair or pairs of calibrating pins and the reference pin and is adapted to sense pulse patterns of the pair of calibrating pins and the reference pin generated during an operational rotation of the coupling. The computational means is communicably coupled to the sensing means and adapted to calculate wear magnitude of the couplings being a function of the pulse patterns and the distance between the pair of calibrating pins.
Typically, the computer implemented coupling wear indicator further includes a display device for indicating real-time wear magnitude of the couplings.
Alternatively, a control panel contains the display device therein.
Further, the computer implemented coupling wear indicator may be provided with a programmable logic controller (PLC) which is adapted to operatively receive signals when the wear limit of the coupling is reached.
In accordance with one embodiment of the invention, the reference pin is adapted to be functionally coupled to the hub of a coupling.
Alternatively, the reference pin is adapted to be disposed on the sleeve of a coupling.
In one embodiment of the present invention, a pin-hub bracket is provided to connect the reference pin to the hub of a coupling.

Additionally, the computer implemented coupling wear indicator may include a warning indicating means for providing a warning signal when the wear limit is reached.
In accordance with one embodiment of the invention, the pair of calibrating pins is adapted to be disposed on the sleeve of a coupling.
Alternatively, the pair of calibrating pins is adapted to be functionally coupled to the hub of a coupling.
Typically, the pair of calibrating pins is adapted to be disposed on the sleeve of a coupling at a distance of 10% of the circumferential distance of the sleeve in the operative configuration of the indicator.
In one embodiment of the present invention, a sensor bracket is provided to connect the sensing means to a gear box.
In one embodiment of the present invention, the sensing means includes a single sensor functionally coupled to the pair of calibrating pins and the reference pin, alternatively, the sensing means includes a first sensor functionally coupled to the pair of calibrating pins and a second sensor functionally coupled to the reference pin.
Typically, a first sensor is provided to sense pulse patterns of the pair of calibrating pins and the second sensor provided to sense pulse patterns of the reference pin.
In accordance with a preferred embodiment of the present invention, there is provided a computer implemented coupling wear indicator comprising:

two pairs of calibrating pins adapted to be disposed on a coupling; a reference pin adapted to be functionally coupled to the hub of the coupling and operatively adapted to be disposed at a center position between the pairs of calibrating pins at the same operative level as the pairs of calibrating pins; each pair of calibrating pins being disposed on either side of the reference pin;
sensing means functionally coupled to the pairs of calibrating pins and the reference pin and adapted to sense pulse patterns of the pairs of calibrating pins and the reference pin generated during an operational rotation of the coupling; and
computational means communicably coupled to the sensing means and adapted to calculate wear magnitude of the coupling being a function of the pulse patterns and the distance between the pairs of calibrating pins.
Typically, in accordance with the above embodiment, the pair of calibrating pins is adapted to be functionally coupled to the sleeve of a coupling.
Additionally, the pairs of calibrating pins and the reference pin are adapted to have different diameters to generate pulses of differing widths,
Typically, in accordance with the present invention, the sensing means comprises sensing elements selected from the group consisting of a piezoelectric element, a capacitive element, a piezoresistant element, pressure sensitive elements, an optical element, proximity sensing element, a piezoelectric PVDF film element, a quartz element, semi conducting elements, a piezoelectric crystal element, Gallium Orthophosphate element,

magnetostrictive element, doped silicon wafer and an eddy current type sensing element.
Additionally, in accordance with the present invention, the computational means is further adapted to selectively consider pulses pulse patterns of 'complete constant speed' cycles only and still further adapted to compute wear magnitude based on an average of the values forming a part of a sub range defining a highest number of consistent wear data from at least 50 cycles.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The invention will now be explained in relation to the accompanying drawings, in which:
FIGURE la illustrates a side perspective view of a coupling wear indicator disposed on a coupling of a machine, in accordance with one embodiment of the invention;
FIGURE lb illustrates a front perspective view of the coupling wear indicator of FIGURE la;
FIGURE 1c illustrates another perspective view of the coupling wear indicator of FIGURE la;
FIGURE 2 illustrates a schematic representation of the coupling wear indicator of FIGURES la to lc in conjunction with an overhead crane assembly;

FIGURE 3a illustrates a front view of the coupling wear indicator of FIGURE la;
FIGURE 3b illustrates a side view of the coupling wear indicator of FIGURE la;
FIGURE 4a illustrates a front view of a coupling wear indicator, in accordance with another embodiment of the present invention;
FIGURE 4b illustrates a side view of the coupling wear indicator of FIGURE 4a;
FIGURE 5 illustrates a schematic representation of a coupling wear indicator, in accordance with yet another embodiment of the present invention;
FIGURE 6 illustrates a schematic representation of a pulse pattern of pins of the coupling wear indicator of the present invention;
FIGURE 7a illustrates a schematic representation of signal response in one direction for bidirectional rotations for the coupling wear indicator of FIGURE 4a; and
FIGURE 7b illustrates a schematic representation of signal response in another direction for bidirectional rotations for the coupling wear indicator of FIGURE 4a.

DETAILED DESCRIPTION
The invention will now be described with reference to the accompanying drawings which do not limit the scope and ambit of the invention. The description provided is purely by way of example and illustration. The block diagram and the description hereto are merely illustrative and only exemplify the invention and in no way limit the scope thereof.
Referring to FIGURES la to 7b, coupling wear indicators in accordance with various embodiments of the present invention are disclosed. The coupling wear indicator of the present invention is adapted to provide realtime wear magnitude of couplings, such as barrel couplings, gear couplings and the like. Accordingly, by providing real-time wear magnitude of couplings, the coupling wear indicator of the present invention prevents sudden failure of the machines/ equipment, such as overhead crane assemblies and the like, are prevented. Additionally, the coupling wear indicator of the present invention provides increased safety to users and persons working around the machine incorporating the coupling wear indicator of the present invention.
Referring to FIGURES la to 3b, a computer implemented coupling wear indicator 100 is disclosed in accordance with one embodiment of the present invention. The coupling wear indicator includes at least one pair of calibrating pins, such as pins 102a and 102b (hereinafter collectively referred to as "pair of calibrating pins 102"), a reference pin 104, sensing means, such as sensor 106 and computational means (not shown).

The pair of calibrating pins 102 is adapted to be disposed on a coupling. More specifically, in one embodiment of the present invention, the pair oi" calibrating pins 102 can be disposed on the sleeve 108 of a coupling. Further, in one operative embodiment of the present invention, the pair of calibrating pins 102 is disposed on the sleeve 108 of a coupling at a distance of 10% of the circumferential distance of the sleeve 108. However, the present invention is not limited to any particular value of the distance used for placement of the pair of calibrating pins 102.
The reference pin 104 is adapted to be functionally coupled to a coupling. More specifically, in one embodiment of the present invention, the reference pin 104 is adapted to be functionally coupled to a hub 110 of the coupling in the operative configuration. Further, in one embodiment of the present invention, the reference pin 104 is connected to the hub 110 of a coupling by means of a pin-hub bracket 114. The reference pin 104 is disposed in between the pair of calibrating pins 102 at the same level as the pair of calibrating pins 102.
Either one sensor 106 is functionally coupled to the pair of calibrating pins 102 and the reference pin 104 and adapted to sense pulse patterns of the pair of calibrating pins 102 and the reference pin 104 or two separate sensors can be provided to sense pulse patterns of the pair of calibrating pins 102 and the reference pin 104 separately. More specifically, a first sensor may be functionally coupled to the pair of calibrating pins 102 and a second sensor may be functionally coupled to the reference pin 104. Accordingly, the first sensor is provided to sense pulse patterns of the pair of calibrating pins 102 and a second sensor may sense the pulse patterns of the reference pin 104.

These pulse patterns are generated when the couplings to which the indicator 100 is fitted is functionally rotated. In one embodiment of the present invention, the sensor 106 is connected to a gear box 116 by means of a sensor bracket 118.
The computational means is communicably coupled to the sensor 106 and adapted to calculate wear magnitude of the coupling. The wear magnitude of the coupling is a function of the pulse pattern of the pair of calibrating pins 102, the distance between the pair of calibrating pins 102 and the pulse pattern of the reference pin 104. Further, FIGURE 2 illustrates a schematic representation of the coupling wear indicator of FIGURES la to lc in conjunction with an overhead crane assembly, wherein the main components depicted include an electric motor 120, a drum 122 of an overhead crane assembly 124.
Referring to FIGURES 4a and 4b, a computer implemented coupling wear indicator 200 is disclosed in accordance with another embodiment of the present invention. The coupling wear indicator 200 includes a reference pin 202, a pair of calibrating pins 204a and 204b (hereinafter collectively referred to as "pair of calibrating pins 204"), sensing means, such as a first sensor 206 and a second sensor 208 and computational means (not shown).
The reference pin 202 is adapted to be disposed on a coupling. More specifically, in the depicted embodiment of the present invention, the reference pin 202 is adapted to be disposed on the sleeve 210 of a coupling. The pair of calibrating pins 204 is adapted to be functionally coupled to the coupling. Specifically, the pair of calibrating pins 204 is adapted to be functionally coupled to the hub 212. The reference pin 202 is disposed in

between the pair of calibrating pins 204. The first sensor 208 is functionally coupled to the pair of calibrating pins 204 and the second sensor 206 is functionally coupled to the reference pin 202. The first sensor 208 is adapted to sense pulse patterns of the pair of calibrating pins 204 and the second sensor 206 is adapted to sense pulse patterns of the reference pin 202. However, in another embodiment of the present invention, the coupling wear indicator 200 includes a single sensor functionally coupled to the reference pin 202 and the pair of calibrating pins 204 to sense pulse patterns of the reference pin 202 and the pair of calibrating pins 204,
The computational means is communicably coupled to the first sensor 206 and the second sensor 208. The computational means is adapted to calculate wear magnitude of the couplings based on the pulse timing of the pair of calibrating pins 204, the distance between the pair of calibrating pins 204 and the pulse timing of the reference pin 202.
By using two sensors, signals from the hub 212 and signals from the sleeve 210 can be differentiated. If the signal from the sleeve 210 is in between the two pulses from the hub 212, more specifically, if the signal from the reference pin 202 is in between the two pulses of the pair of calibrating pins 204, then wear is calculated only from such cycles. This logic for detecting constant, reversible, variable speed cycles is easy as a user can differentiate hub and sleeve signals. Further, value of the distance between the pair of calibrating pins 204 is utilized for calibration of the 'Time Vs Distance' in that cycle zone. Based on the timing of pulses from the reference pin 202, a value of wear is calculated.

Referring to FIGURE 5, a computer implemented coupling wear indicator
300 is disclosed, in accordance with a preferred embodiment of the present
invention. The coupling wear indicator 300 includes two pairs of calibrating
pins, such as a first pair 302a, 302b, and a second pair 302c and 302d
(hereinafter collectively referred to as "two pairs of calibrating pins 302"),
one reference pin, such as a reference pin 304 and sensing means, such as a
sensor 306. The two pairs of calibrating pins 302 is adapted to be disposed
on a sleeve and the reference pin 304 is adapted to be functionally coupled
to a hub and disposed at a center position of the two pairs of calibrating pins
302. More specifically, the reference pin 304 is disposed amongst the two
pairs of calibrating pins 302 in a way such that a pair of pins of the two pairs
of calibrating pins 302 is disposed on either side of the reference pin 304
such that the distance between the calibrating pins 302a and 302b of a pair
and the distance between the calibrating pins 302c and 302d of the other pair
is half the distance between the pairs of calibrating pins i.e. the distance
between the calibrating pins 302b and 302c. This relationship is generally
indicated in FIGURE 5 as distance X between the calibrating pins of a pair
and distance 2X between the pairs of calibrating pins. Additionally, the
reference pin 304 is disposed at the same operative level as the two pairs of
calibrating pins 302. A sensing means comprising a first sensor and a
second sensor is used to sense the pulse patterns of the pairs of calibrating
pins and the reference pin separately. However, apart from the cost of the
additional sensor, mounting difficulties and accordingly a possibility of error
make the use of two sensors disadvantageous. The preferred embodiment
uses only one sensor to pick up pulses from all the five pins.

In accordance with one aspect of the present invention, diameters of the two pairs of calibrating pins 302 and the diameter of the reference pin 304 is adapted to be different from each other so that these two pairs of calibrating pins 302 and the reference pin 304 generate different pulse widths. However, the present invention is not limited to similarities and dis-similarities of the diameters of the two pairs of calibrating pins 302 and the reference pin 304. Alternatively, in another embodiment of the present invention, diameters of the pairs of calibrating pins 302 and the reference pin 304 are the same.
Now referring to FIGURE 6 in conjunction with FIGURES la to 3b, wear calculations are done by identifying pulse patterns of the hub 110 and the sleeve 108 using the sensor 106. Wear is calculated by measuring relative circumferential movement between the hub 110 and the sleeve 108. Considering variable speed and bidirectional rotations in crane / hoisting applications, firstly there is a need to identify 'complete', 'constant speed' and 'single direction' cycles. Using such cycles, 'Time vs. Distance' calibration is performed to calculate actual wear. The pulse patterns facilitate to differentiate 'complete constant speed' cycles from various other cycles such as incomplete, reversible, intermittent or variable speed cycles in an application. The 'complete constant speed' cycles facilitates the calculation of wear magnitude, as a reliable 'Time Vs Distance' calibration is obtained from such a 'complete constant speed' cycle. In one embodiment of the present invention, the pair of calibrating pins 102a and 102b is fixed on the sleeve ]08 of the coupling at a distance of 10% of circumferential distance of the sleeve 108. If 'd' represents the circumferential distance, '10%d' refers to the distance from calibrating pins 102a and 102b while '90%d'

refers to the distance from the calibrating pin 102b to 102a around the circumference of the coupling.
Since the distance between the two calibrating pins 102a and 102b is fixed, it can be used for calibration for each cycle. If a 3rd pulse (travel from pin 1 to pin 3) is after 10% time and if the next pulse (travel from pin 3 to pin 1) is after 90% time, then it is a 'complete constant speed' cycle. 'Time Vs Distance' calibration is done using the 1st and 3rd pulse 'timing' and from a known 'fixed 10% distance' between these 1st and 3rd pins, in a constant speed cycle. Now, from the 2nd pulse timing (Hub), the relative wear with respect to 1st and 3rd pulses (Sleeve), based on the above 'Time Vs Distance' calibration is calculated.
If the above-mentioned 10% + 90% time pattern is not obtained from the initial reference pulse, then that reference pulse is ignored and the next pulse is taken as a reference pulse. Now the 10% + 90%o time pattern is checked again with respect to the new reference pulse. This check is continued until complete constant speed cycles are obtained. Once such complete constant speed cycles are identified, a good quality 'Time Vs Distance' calibration is obtained for that cycle. The distance between calibrating pins 1 and 3 is known and is always fixed. Accordingly, the required time to travel the known distance from 1 st to 3rd pin is captured.
If tl is the time taken to get the pulse after a travel from pin 1 to 3, and t2 and t3 refer to the time taken to get the pulse after a travel from pin 1 to pin 2 and from pin 2 to pin 3 respectively, then, tl = t2 + t3, wherein |t2| = |t3|.

When there is wear, since the reference pin 104 shifts from the default central location between the pair of calibrating pins 102a and 102b, the new time taken to get the pulse after a travel from pin 1 to pin 2 and from pin 2 to pin 3 are referred to as t4 and t5 respectively; the time tl remaining constant. In the event of wear, the relationship between time t, t4 and t5 is tl = t4 +15, wherein |t4| ± jt5|.
The unit of measurement of the time t4 and t5 is millimeters (mm)
A value |t4j - |t5| corresponds to the wear magnitude in mm.
There are chances of getting abrupt wear readings due to sudden jerks or operating misalignments. However, the core logic is adapted to ignore such sudden wear values with respect to consistent wear readings. More specifically, the wear value is displayed based on probability analysis of at least 50 cycles of wear data. A minimum and a maximum wear value out of the 50 cycles are recorded. This wear range is divided (maximum minus minimum value) into 5 sub-ranges. These sub-ranges are checked to find out the sub-range that has given a highest number of consistent wear data. An average of those sub-range wear readings is displayed on a display device. The logic is uploaded to a processing unit, such as a microprocessor for calculation of the real-time wear magnitude to be displayed on a display device. FIGURES 7a and 7b illustrate the wear calculation logic for bidirectional rotations within a cycle. The concept of wear calculation as explained with reference to FIGURE 6 is also applied to FIGURES 7a and 7b. Accordingly, when the direction of rotation changes, the wear calculations are performed when one cycle is completed.

Further, the coupling wear indicator 100 includes a display device 112 (shown in FIGURE 2) for indicating real-time wear magnitude of the coupling. In one embodiment of the present invention, the display device 112 is disposed within a control panel of a machine, such as an overhead crane assembly 124 and the like, for facilitating an operator to monitor realtime wear magnitude of the coupling. In one embodiment of the present invention, the display device 112 is adapted to digitally display the real-time wear magnitude of the coupling. Accordingly, in one embodiment of the present invention, the display device 112 is also referred to as an 'Electronic Wear Display Box'. Further, the display device 112 is communicably coupled to a processing unit, such as a microprocessor of the machine, such as the overhead crane assembly 124 and the like. Alternatively, the display device 112 is a microprocessor based display device.
Additionally, in one embodiment of the present invention, the coupling wear indicator 100 includes a programmable logic controller (PLC) adapted to receive signals when the wear limit of the coupling is reached. Moreover, in one embodiment of the present invention, the coupling wear indicator 100 includes a warning indicating means (not shown) for providing a warning signal when the wear limit is reached. The warning indicating means is selected from various forms such as an alarm sound, a continuous visual blinking, combination of an alarm sound and a continuous visual blinking and the like.
Now referring to FIGURE 6 in conjunction with FIGURE 5, coupling wear is determined by determination of a complete non-reversed cycle. For determination of complete non-reversed cycle, if two bigger pulse widths are

obtained on each side of the smaller pulse width, then it implies that there is no reversible rotation in between the IP and 5P pins cycle sector. Thus providing two pairs of calibrating pins 302 (IP, 2P, 4P, 5P) eliminates the need for a complete rotation to select a 'complete constant speed cycle' for wear calculation, as is the case in the embodiment wherein only one pair of calibrating pins is used. A good cycle in the embodiment of FIGURE 5 can be judged based solely on the 'Time Vs Distance' calibration / the angular displacement in the sector between the pins IP and 5P.
Distance between the two pairs of calibrating pins 302 (IP, 2P, 4P, 5P) is fixed and known. From the timings of«IP to 2P\ '2P to 4P' & '4P to 5P\ a user can get 3 calibrations of the 'Time Vs Distance' in that cycle sector. If these three calibrations are consistent within acceptable deviation, only then that cycle is considered for wear calculations. By doing the calibration thrice, it is ensured that the speed does not vary between the IP and 5P pins cycle sector and wrong wear readings are not obtained due to minute fluctuations in speed.
Wear is equivalent to absolute timing difference between 2G and 3G. Based on the above 'Time Vs Distance' calibration and the time difference between 2G-3G in that cycle sector, the actual wear value is calculated. There are chances of getting a few odd readings due to angular misalignments, jerks and the like. But, wear value is displayed based on probability analysis of the at least 50 cycles of wear data. A minimum and a maximum wear value out of the 50 cycles are recorded. This wear range is divided (maximum minus minimum value) into 5 sub-ranges. These sub-ranges are checked to find out the sub-range that has given a highest number of consistent wear

data. An average of those sub-range wear readings is displayed on a display device, such as the display device 112.
The principles of the present invention can be extended to other coupling arrangements such as gear couplings to measure wear of a gear mesh. For measurement of wear of a gear mesh, a pair of sensors is mounted on the gear couplings at an angle of 90 degrees to each other in a plane of measurement. Using the pair of sensors, the values obtained due to angular misalignment are differentiated from the actual wear values. If both the sensors give the same reading, then it is a wear value, otherwise it is a value obtained due to angular misalignment.
The calibrating pins and the reference pin referred to in various embodiments herein above are made of steel or a magnetic material. The sensing means referred herein above in the specification comprises sensing elements such as a piezoelectric element, a capacitive element, a piezoresistant element, pressure sensitive elements, an optical element, proximity sensing element, a piezoelectric PVDF film element, a quartz element, semi conducting elements, a piezoelectric crystal element, Gallium Orthophosphate element, magnetostrictive element, doped silicon wafer and an eddy current type sensing element.

TECHNICAL ADVANCEMENTS AND ECONOMIC
SIGNIFICANCE
The coupling wear indicator of the present invention is adapted to provide real-time wear magnitude of couplings. More specifically, the coupling wear indicator is adapted to provide real-time wear magnitude of couplings based on the average of many cycles and thereby prevents false wear magnitudes. Further, the coupling wear indicator of the present invention precludes assembly / disassembly thereof based on loading direction. More specifically, the coupling wear indicator of the present invention is simple in construction. Still further, the coupling wear indicator is convenient, user friendly and effective. Further, the coupling wear indicator prevents sudden failure of the coupling. Still further, the coupling wear indicator is easy to install. Further, the coupling wear indicator of the present invention reduces maintenance cost and maintenance time of machines / equipment.
The numerical values given for various physical parameters, dimensions and quantities are such that they envisage values higher or lower than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the invention unless there is a statement in the specification to the contrary.
Wherever a range of values is specified, a value up to 10% below and above the lowest and highest numerical value respectively, of the specified range, is included in the scope of the invention.
While considerable emphasis has been placed herein on the particular features of this invention, it will be appreciated that various modifications

can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the invention. These and other modifications in the nature of the invention or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby 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.

Claims:
I. A computer implemented coupling wear indicator for determining real-time wear magnitude of couplings, said coupling wear indicator comprising:
• at least one pair of calibrating pins adapted to be disposed on a coupling;
• a reference pin adapted to be functionally coupled to said coupling and operatively adapted to be disposed in between said pair of calibrating pins;
• sensing means functionally coupled to said pair or pairs of calibrating pins and said reference pin and adapted to sense pulse patterns of said pair of calibrating pins and said reference pin generated during an operational rotation of the coupling; and
• computational means communicably coupled to said sensing means and adapted to calculate wear magnitude of said coupling being a function of said pulse patterns and the distance between said pair of calibrating pins.

2. The computer implemented coupling wear indicator as claimed in claim 1, further comprising a display device for indicating real-time wear magnitude of said couplings.
3. The computer implemented coupling wear indicator as claimed in claim 2, further comprising a control panel adapted to contain said display device therein.

4. The computer implemented coupling wear indicator as claimed in claim 1, further comprising a programmable logic controller (PLC) adapted to operatively receive signals when the wear limit of said coupling is reached.
5. The computer implemented coupling wear indicator as claimed in claim 1, wherein said reference pin is adapted to be functionally coupled to the hub of a coupling at the same operative level as said pair of calibrating pins.
6. The computer implemented coupling wear indicator as claimed in claim 1, wherein said reference pin is adapted to be disposed on the sleeve of a coupling.
7. The computer implemented coupling wear indicator as claimed in claim 1, further comprising a pin-hub bracket adapted to connect said reference pin to the.hub of a coupling.
8. The computer implemented coupling wear indicator as claimed in claim 1, further comprising a warning indicating means for providing a warning signal when the wear limit is reached.
9. The computer implemented coupling wear indicator as claimed in claim 1, wherein said pair of calibrating pins is adapted to be functionally coupled to the sleeve of a coupling.

10. The computer implemented coupling wear indicator as claimed in claim 1, wherein said pair of calibrating pins is adapted to be functionally coupled to the hub of a coupling.
11. The computer implemented coupling wear indicator as claimed in claim 1, wherein said pair of calibrating pins is adapted to be disposed on the sleeve of a coupling at a distance of 10% of the circumferential distance of said sleeve in the operative configuration.
12. The computer implemented coupling wear indicator as claimed in claim 1, further comprising a sensor bracket adapted to connect said sensing means to a gear box.
13. The computer implemented coupling wear indicator as claimed in claim 1, wherein said sensing means comprises a first sensor functionally coupled to said pair of calibrating pins and a second sensor functionally coupled to said reference pin.
14. The computer implemented coupling wear indicator as claimed in claim 13, in which said first sensor is adapted to sense pulses of said pair of calibrating pins and said second sensor adapted to sense the pulses of said reference pin.
15. A computer implemented coupling wear indicator as claimed in claim 1, said coupling wear indicator comprising:
• two pairs of calibrating pins adapted to be disposed on a coupling;

• a reference pin adapted to be functionally coupled to said coupling and operatively adapted to be disposed at a center position between said pairs of calibrating pins at the same operative level as said pairs of calibrating pins; each pair of calibrating pins being disposed on either side of said reference pin;
• sensing means functionally coupled to said pairs of calibrating pins and said reference pin and adapted to sense pulse patterns of said pairs of calibrating pins and said reference pin generated during an operational rotation of the coupling; and
• computational means communicably coupled to said sensing means and adapted to calculate wear magnitude of said coupling being a function of said pulse patterns and the distance between said pairs of calibrating pins.

16. The computer implemented coupling wear indicator as claimed in claim 15, wherein said reference pin is adapted to be functionally coupled to the hub of a coupling.
17. The computer implemented coupling wear indicator as claimed in claim 15, wherein said pair of calibrating pins is adapted to be functionally coupled to the sleeve of a coupling.
18. The computer implemented coupling wear indicator as claimed in claim 15, wherein said pairs of calibrating pins and said reference pin are adapted to generate pulses of differing widths.

19. The computer implemented coupling wear indicator as claimed in claim 15, wherein diameters of said pairs of calibrating pins differ from the diameter of said reference pin.
20. The computer implemented coupling wear indicator as claimed in claim 1, wherein said sensing means comprises sensing elements selected from the group consisting of a piezoelectric element, a capacitive element, a piezoresistant element, pressure sensitive elements, an optical element, proximity sensing element, a piezoelectric PVDF film element, a quartz element, semi conducting elements, a piezoelectric crystal element, Gallium Orthophosphate element, magnetostrictive element, doped silicon wafer and an eddy current type sensing element.
21. The computer implemented coupling wear indicator as claimed in claim 1, wherein said computational means is further adapted to selectively consider pulse patterns of'complete constant speed' cycles only and still further adapted to compute wear magnitude based on an average of the values forming a part of a sub range defining a highest number of consistent wear data from at least 50 cycles.
22. The computer implemented coupling wear indicator as claimed in claim 1, wherein said sensing means comprises a pair of sensors mounted on a gear coupling at an angle of 90 degrees to each other in a plane of measurement; and said computational means is further adapted to selectively consider pulse patterns only when said pair of sensors generate identical readings.

23. The computer implemented coupling wear indicator as claimed in claim 1 , wherein said reference pin is disposed in between said at least one pair of calibrating pins at the same operative level.