Title of Invention

A SYSTEM FOR MEASURING DIMENSIONS OF ANY CIRCULAR OBJECT HAVING ATLEAST ONE CENTRAL BORE

Abstract A system for measuring dimensions with accuracy of about 0.2 mm of any circular object having a central bore alongwith profile of the object and eccentricity comprising a centering device adapted to determine the central axis of the bore and measuring means adapted for measurement of dimensions in any direction in relation to the central axis of the bore and means for digital display of the measured dimensions. In particular, the system would provide for measurement of all types of wheels. The system provides for measurement of dimension in two planes at the same time by way of a more accurate and consistent measurement means avoiding any possible variation in measurement due to change of operator. The system is simple to operate. A faster measurement by the system enables initiation of corrective steps to overcome defects in production. The system is robust to withstand harsh industrial environment and would be cost-effective and maintenance free.
Full Text The present invention relates to a novel system for measuring dimensions of any circular object having a central bore. The system is adapted to measure all major dimensions of any circular object having a central bore along with profile of the object and eccentricity in the object. More particularly, the invention relates to a system for measuring dimensions of Rail Road Wheel in cold condition. >.
It is presently known to measure dimensions of rail road wheel following the steps discussed hereunder:
i. After dishing operation, one mobile charger holds the wheel.
ii. One operator then takes the dimension of the wheel, with Go/No Go
gauges.
iii. Only few dimensions of the wheel are measurable in this manner, iv. When wheel becomes cold then other dimensions are taken, v. Wheel is placed on the floor of the shop, vi. With the help of callipers and scale, dimensions of the wheel are
measured, vii. Dimension in Z-plane is measured with the help of two scales.
It is experienced that the above known art of measuring dimensions of rail road wheel have limitations/drawbacks as discussed hereunder:
i. Due to variation in process many a times these wheels are eccentric which
could not be measured using the known system. This eccentricity leads to
wash out at different places of the wheels during subsequent process
resulting in rejection of the wheels, ii. In such known system of dimension measurement, it was very difficult to
measure dimensions in two planes at the same time, iii. In the known system measured dimensions usually varied from operator to
operator, iv. In the known system measured dimensions were dependent on operators
eye estimation, v. Also in such known system there was no provision for display of measured
dimension digitally.

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It is thus the basic object of the present invention to provide for a system whereby eccentricity of wheels could be measured thereby leading to reduction in rejection of wheels in subsequent processing.
Another object of the present invention is to provide a system for measuring dimensions of circular objects whereby the measurement can be taken in two planes at a same time.
Another object is to provide a system for measuring dimensions of circular objects which would provide for more accurate and consistent measurement of dimensions and would avoid variation in measurement due to change of operator. The system of measuring would enable accurate measurement with accuracy of about 0.2 mm which is much improved than the accuracy of 1 mm of the presently known systems.
Further object is directed to provide a measuring system which would measure the dimensions of circular objects and would be adapted to display all the measured dimensions digitally.
Yet further object is to provide a system of measuring dimensions of circular objects which would enable segregation of products differently depending on their dimensions and eccentricity. This would lead to faster rate of production down the line depending on dimensions of the circular objects which was not possible in the previous known systems.
Yet another object of the present invention is to enable measurement of dimensions and provide information about dimensions quickly so that corrective action may be taken immediately to overcome that defect. It can be adapted to set any point as reference and all the measurement can be done with reference to that point thereby avoiding any mathematical operation to know dimensions.

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Yet further object of the invention is to provide a system which would provide for measurement of all types of wheels that can be measured at one place and without changing any parameter.
Yet further object is to provide a system of measuring dimensions which apart from wheels can also measure dimensions of other circular objects having a central bore.
Yet another object is to provide a system of measuring dimensions of circular objects which would be robust to withstand the harsh industrial environment would be cheap, easy to operate and provide almost maintenance free dimension measuring system.
Summary of the Invention
Thus according to the present invention there is provided a system for measuring dimensions of any circular object having atleast one central bore comprising:
a centering device (CD) provided with collapsible unit (CU) and supporting
measuring arm (MA) adapted to determine the central axis of the bore;
measuring means (MD) comprising shaft encoder (SE) adapted for measurement of
dimensions in any direction in relation to the central axis of the bore determined by
said centering device (CD);
means for indication of the measured dimensions;
a support means (CL) adapted to rotatably support an arm holding said centering
device (CD);
said measuring arm (MA) rotatably supported with respect to said centering device
(CD) and having adjacent its free end said measuring members for measuring of
said dimensions after determination of the centre of the bore with said centering
means.
The measuring arm is preferably a flexible arm so that the centering device and the measuring arm can be reached in said bore the dimensions of which need to be measured.

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In the above disclosed system for measuring the internal dimensions of circular objects it is possible to determine the centre of the circular object such as a wheel by use of the centering device. The centering device is adapted to be inserted into the bore and then expanded to grip the internal walls of the bore. The centering device therefore assists in deciding the central axis of the bore and facilitates accurate measuring of the dimensions of the bore.
The measuring arm is preferably obtained of stainless steel and provided to have sufficient rigidity. The cross section of the measuring arm was selected to withstand cantilever force due to two nos. of sensing devices and brackets with pointer.
The shaft encoder means comprise rotary shaft encoder to measure dimensions in both horizontal and vertical planes. The measuring means is preferably provided with digital read out means for indication of the measured dimensions.
In accordance with yet preferred aspect, the system for measuring comprise of said measuring means comprising two shaft encoders adapted for measurement of dimensions in both horizontal and vertical planes.
The details of the invention, its objects and advantages are explained hereunder in greater detail in relation to the nonlimiting exemplary embodiment and accompanying figures wherein
Fig. 1 is a schematic illustration of the system for measuring in accordance with the present invention, and
Fig. 2 is a schematic illustration of the sectional view of the centering device used in the system of the invention.
Reference is invited to Fig. 1 which shows the various components constituting the system of the invention. As shown in said figure, the system comprises a support structure which includes a column (CL) having a base (BA) which is

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bolted to the ground using base bolts (BB). The column (CL) rotatably supports the centering device (CD) via a flexible arm (FA). The CD is provided with collapsible unit (CU) and supports a measuring arm (MA) having at its free end the shaft encoders (SE) used for measuring of dimensions. The detailed construction of the various components used in the measuring system are provided hereunder.
The support column:
The column (CL) is preferably fabricated from MS plate and consists of base plate body and
having said cross section.
Collapsible Centering Device :
This system of the invention is adapted to determine centre of the wheel with help of a centering device (CD). The Centering Device is essentially a device which is a central axis of any circular object with relation to its bore. It consists of one collapsible unit and one handle. The centering device is provided with dimensions and shaped to avoid hindrance by the burrs at the bore of the wheels. For deciding centre of the wheel this centering device is inserted in the bore of the wheel with help of handle means (HM2) and then rotated clockwise so that the centering device is expanded with help of handle means (HM1) so that it grips the walls of the bore. When the handle is rotated anti-clockwise, the devise collapses enabling the user to remove the centering device from the bore. In the measuring system of the invention the central bore axis is taken as the centre of the wheel. The axis of centering device is adapted for use in any type of wheels.
The Measuring Arm :
The measuring arm (MA) is also preferably obtained of stainless steel. The measuring arm cross section was selected in such a way so as to withstand the cantilever force due to two nos. of sensing devices (SD) and brackets with pointer. The arm is provided with sufficient rigidity. The measuring arm is attached with the centering device. On the arm of the movable shaft encoders and pointers are fitted and placed in a box. This box is movable on the Measuring Arm; movement is rack and pinion type. The movement of the bracket is on lead screw for smooth and precise movement over the measuring arm. The tip of the pointer is made of carbide to withstand impact and abrasion with the wheel. The shaft encoder reads distance of the central axis from the pointer and this is digitally displayed. Similarly, pointer can be moved up and down and it can be placed to the point. Distance of the point from the central axis as well as vertical distance is digitally displayed. This arm is capable of rotating in horizontal plane perpendicular to the axis of Centering Device.

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Measuring Device/Measasing Means :
Measuring device (MD) consists of two nos. of rotatory shaft encoder (SE) to
measure dimensions in both horizontal and vertical planes. Preferably, it has
supply voltage of 5 volts DC and output pulses as 380 PPR. Supply current is 50
to 70 mA and output frequency is 25 Khz (max.). Shaft of these encoders are
preferably, made of stainless steel having diameter of 6 mm. :
Measuring device is provided with atleast one digital read out. Display unit ,(DU) is preferably 4 digits, 7 segments red LED of 20 mm height. Its supply voltage is 220 volts and resolution of 0.1 mm. The display unit (DU) can be preferably mounted with respect to the column (CL) as shown in Fig. 1.
In accordance with a preferred aspect the system of the invention can also incorporate recording facility and for the purpose a recording means can be provided to record to measured dimensions indicated by the indication means.
The method of carrying out the measurement of bore dimension of wheel using the system of the invention involve the following simple steps:
i. At first wheel is placed on the measuring platform located in front of the
invention.
ii. Power of the control panel is switched ON. iii. Then X and Z axis measurement switches are ON. iv. Then the centering device is placed over the bore of the wheel and
handwheel of the centering device is rotated to place centering device
inside the bore, v. Then top hand wheel of the centering device is tightened so that three
jaws open and lock inside the bore at equal distance, vi. Now knobs of the measuring devices are turned so that pointer is placed
at the required location for measurement. The digital read out gives
directly the vertical and horizontal readings, vii. The measuring arm now may be rotated to any direction in which further
readings are required.

viii. Once the measurement is complete top and side handwheels are unlocked and centering device is lifted from the wheel.
It is thus possible by way of the present invention to provide a novel system of measurement of dimensions of circular objects with central bore which would be simple to operate and provide for a more accurate measurement of dimensions as compared to presently known system.

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WE CLAIM :
1. A system for measuring dimensions of any circular object having atteast one central
bore comprising:
a centering device (CD) provided with collapsible unit (CU) and supporting
measuring arm (MA) adapted to determine the central axis of the bore;
measuring means (MD) comprising shaft encoder (SE) adapted for measurement of
dimensions in any direction in relation to the central axis of the bore determined by
said centering device (CD);
means for indication of the measured dimensions;
a support means (CL) adapted to rotatably support an arm holding said centering
device (CD);
said measuring arm (MA) rotatably supported with respect to said centering device
(CD) and having adjacent its free end said measuring members for measuring of
said dimensions after determination of the centre of the bore with said centering
means.
2. A system for measuring dimensions as claimed in claim 1 wherein said measuring
arm is preferably a flexible arm adapted such that the centering device and the
measuring arm can be reached in said bore the dimensions of which need to be
measured.
3. A system for measuring dimensions as claimed in anyone of claim 1 or 2 wherein
said centering device is adapted to be inserted into the bore and comprise means to
grip the internal walls of the bore to facilitate determining of the centre of the bore
and measuring of the dimensions of the bore.
4. A system for measuring dimensions as claimed in anyone of claims 1 to 3 wherein
said measuring arm is preferably obtained of stainless steel and provided to have
sufficient rigidity.

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5. A system for measuring dimensions as claimed in anyone of claims 1 to 4 wherein
the cross section of the measuring arm is selected to withstand cantilever force due
to sensing devices and brackets with pointer.
6. A system for measuring dimensions as claimed in anyone of claims 1 to 5 wherein
said shaft encoder means comprise rotary shaft encoder to measure dimensions in
both horizontal and vertical planes.
7. A system for measuring dimensions as claimed in anyone of claims 1 to 6 wherein
said measuring means is preferably provided with digital read out means for
indication of the measured dimensions.
8. A system for measuring dimensions as claimed in anyone of claims 1 to 7 wherein
said measuring means comprising two shaft encoders adapted for measurement of
dimensions in both horizontal and vertical planes.
9. A system for measuring dimensions as claimed in anyone of claims 1 to 8 wherein
said support means comprise a support structure comprising a column having a base
which is adapted to be bolted to the ground using bore bolts.
10. A system for measuring dimensions as claimed in claim 9 wherein said column
rotatably supports the centering device via a flexible arm.
11. A system for measuring dimensions as claimed in anyone of claims 1 to 10 wherein
said column is preferably obtained from MS plate and consists of base plate body
and having selected cross section.
12. A system as claimed in anyone of claims 1 to 11 wherein said centering device is
provided with handle means to facilitate its manoeuvring for determination of the
centre of the bore.
13. A system as claimed in anyone of claims 1 to 12 wherein said centering device is
provided with dimensions and shaped to avoid hindrance by the burrs at the bore of
the circular object.

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14. A system as claimed in anyone of claims 1 to 13 wherein said measuring arm is
preferably obtained of stainless steel.
15. A system as claimed in anyone of claims 1 to 14 wherein said measuring arm cross
section is selected such as to withstand the cantilever force due to sensing devices
and brackets with pointer.
16. A system as claimed in claim 15 wherein the brackets are adapted to move on lead
screw for smooth and precise movement over the measuring arm.
17. A system as claimed in anyone of claims 1 to 18 wherein the tip of the pointer is
made of carbide to withstand impact and abrasion with the wheel.
18. A system as claimed in anyone of claims 1 to 17 wherein the arm is adapted for
rotating in horizontal plane perpendicular to the axis of centering device.
19. A system as claimed in anyone of claims 1 to 18 wherein the measuring means
preferably have supply voltage of 5 volts DC and output pulses as 380 PPR with
supply current of 50 to 70 mA and output frequency of 25 Khz (max).
20. A system as claimed in anyone of claims 1 to 19 wherein the shaft of the encoders
are preferably made of stainless steel having diameter of 6 mm.
21. A system as claimed in anyone of claims 1 to 20 wherein the measuring means is
provide with atleast one digital read out.
22. A system as claimed in claims 21 wherein the display unit is preferably 4 digits, 7
segments red LED of 20 mm height and having supply voltage 220 volts and
resolution of 0.1 mm.
23. A system as claimed in anyone of claims 21 or 22 wherein said display unit is
mounted on said support member/column.

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24. A system as claimed in anyone of claims 1 to 23 comprising means to record
measured dimensions indicated by the indication means.
25. A method of carrying out the measurement of bore dimension of circular object such
as wheel using the system as claimed in anyone of claims 1 to 24 comprsing :
i. providing the wheel on the measuring platform ;
ii. switching on the power of the control panel;
iii. putting on the X and Z axis measurement switches ;
iv. placing the centering device over the bore of the wheel and handwheel of the
. centering device is rotated to place centering device inside the bore ; v. tightening the top hand wheel of the centering device so that the jaws open
and lock inside the bore at equal distance, vi. turning the knobs of the measuring devices so that pointer is placed at the
required location for measurement to thereby obtain digital read out directly of
the vertical and horizontal readings ; vii. rotating the measuring arm to any direction in which further readings are
required ; viii. once the measurement is complete top and side handwheels are unlocked
and centering device is lifted from the wheel.
26. A system for measuring dimensions of circular objects having atleast one central
bore substantially as herein described and illustrated with reference to the
accompanying figures.
A system for measuring dimensions with accuracy of about 0.2 mm of any circular object having a central bore alongwith profile of the object and eccentricity comprising a centering device adapted to determine the central axis of the bore and measuring means adapted for measurement of dimensions in any direction in relation to the central axis of the bore and means for digital display of the measured dimensions. In particular, the system would provide for measurement of all types of wheels. The system provides for measurement of dimension in two planes at the same time by way of a more accurate and consistent measurement means avoiding any possible variation in measurement due to change of operator. The system is simple to operate. A faster measurement by the system enables initiation of corrective steps to overcome defects in production. The system is robust to withstand harsh industrial environment and would be cost-effective and maintenance free.

Documents:

00613-cal-2000-abstract.pdf

00613-cal-2000-claims.pdf

00613-cal-2000-correspondence.pdf

00613-cal-2000-description(complete).pdf

00613-cal-2000-drawings.pdf

00613-cal-2000-form-1.pdf

00613-cal-2000-form-2.pdf

00613-cal-2000-form-3.pdf

00613-cal-2000-letters patent.pdf

00613-cal-2000-p.a.pdf


Patent Number 200503
Indian Patent Application Number 613/CAL/2000
PG Journal Number 07/2007
Publication Date 16-Feb-2007
Grant Date 16-Feb-2007
Date of Filing 06-Nov-2000
Name of Patentee STEEL AUTHORITY OF INDIA LIMITED.
Applicant Address RESEARCH AND DEVELOPMENT CENTRE FOR IRON & STEEL, DORANDA, RANCHI-834002
Inventors:
# Inventor's Name Inventor's Address
1 JHA SAMIR KUMAR RESEARCH AND DEVELOPMENT CENTRE FOR IRON & STEEL, STEEL AUTHORITY OF INDIA LIMITED., DORANDA, RANCHI-834002
2 JAIN DINESH KUMAR RESEARCH AND DEVELOPMENT CENTRE FOR IRON & STEEL, STEEL AUTHORITY OF INDIA LIMITED., DORANDA, RANCHI-834002
3 GUPTA DAYA SHANKAR RESEARCH AND DEVELOPMENT CENTRE FOR IRON & STEEL, STEEL AUTHORITY OF INDIA LIMITED., DORANDA, RANCHI-834002
4 ROY BASUDEO RESEARCH AND DEVELOPMENT CENTRE FOR IRON & STEEL, STEEL AUTHORITY OF INDIA LIMITED., DORANDA, RANCHI-834002
PCT International Classification Number G01D 1/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA