Title of Invention

A CONTACT OR NON-CONTACT TYPE DIGITAL APPARATUS FOR MEASURMENT OF FILLET WELD SURFACE PROFILE

Abstract A contact or non-contact type digital gauge apparatus for measurement of fillet weld surface profile comprising of two measuring devices (5) and (6) mounted on a slide (7) and integrated with a processing unit with a built-in algorithm, a base (4) fixed on a horizontal part (2), a vertical shaft guide (3) mounted on the base, the two measuring devices (5 & 6) measuring the distances between the measuring devices and selected locations (such as A, B, C & D) on the fillet (8) and above the fillet, one device (5) measuring at selected points the distances from this device to the vertical part of the component joined to the horizontal part by the fillet (8) and the other device (6) measuring the distances between the measuring device and the horizontal surface (base) of the component for all the selected points measured by the other device (5), feeding the measured distances as data inputs in a processing unit and computing the fillet dimensions through a built-in algorithm in the processor and displaying the same in a display device.
Full Text -2-
FIELD OF THE INVENTION
This invention refers to the development of Digital gauge for measuring various
dimensions of a completed fillet weld.
BACKGROUND OF THE INVENTION
Fillet weld is a weld at the junction of two parts, e.g. plates at right angles to
each other, in which a fillet of welding metal is laid down in the angle created by
the intersection of the surfaces of the parts.
Fillet welds are widely used in several applications either as single pass weld or a
multi-pass weld. This involves welding of different thickness material which may
be of steel or non ferrous categories. At least one of the edges joined may also
have edge preparations. During welding one of the members may distort so that
the initial angle between the two components before welding may be changed
due to distortion. In practical conditions the weld gauge has to take in to
consideration the factors like the surface profile of the fillet, equal or unequal leg
sizes, the angle between the components joined etc. while measuring the weld
dimensions.

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The mechanical gauges have been developed and applied for this purpose.
However, in the application of these gauges, the accuracies are limited by nature
of the bead surface - Concavity / Convexity or metere joint and the angle
between plate surfaces joined by the fillet. In order to eliminate these difficulties
a new type of gauge is proposed which would give a digital output of the leg
sizes and throat size of he fillet after the required measurements and
calculations. In addition the gauge can be used for measuring the edge
preparation angle of a bevel edge prepared plate/pipe.
As prior art references in this field
Patent No. GB439319 has described a gauge for checking dimensions relating
to welded joints in which one or more blade like members, shaped and
dimensioned at the ends and/or sides in accordance with suitable shapes and
sizes for said joints, are pivoted in a holder, so as to be opened out for use and
closed into the holder when not in use.

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Document W00221071 has disclosed an adjustable gauge having special
application to the measuring of the dimensions of a fillet weld. The gauge
includes a first plate and a second plate wherein the plates are rotatably
mounted about an axis of rotation and juxtaposed to one another. The gauge
also includes a linear member rotatably mounted on the same axis of rotation as
the first and second plates juxtaposed to the second plate on a first face
opposite the first plate. The linear member is slidably mounted in relation to the
first and second plates in order to extend so as to measure the dimension of a
weld. The first plate is substantially rectangular in shape and terminates in an
edge, which traverses one corner thereof. The second plate is substantially
circular in shape. A front face of the first plate, which is adjacent to the second
plate, has a recess thereon sized to accommodate the second plate. The first
plate, the second plate, and the linear member are rotatably mounted to one
another with a spring based mechanism for increasing and decreasing the
rotational resistance there between.
The above state of prior art suffers from the difficulties that the gauges are
limited in accuracies in measurement of dimensions in respect of complex
formation of weld profile and change of angle between the two members during
welding.

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OBJECTS OF THE INVENTION
One object of the present invention is to develop a non-contact type digital
measurement apparatus for measuring the leg sizes of the fillet welds, which
may be equal or unequal leg sizes.
Another object of the invention is to measure the throat size of the fillet weld
that may have a concave or convex weld profile.
Yet another object of the invention is to measure the angle of edge preparation.
A further object of the invention is to carry out the measurement through non-
contact measurement systems by using a single mathematical program for
arriving at the desired dimensions.
According to the invention there is provided a contact or non-contact type digital
gauge apparatus for measurement of fillet weld surface profile comprising of two
measuring devices mounted on a slide and integrated with a processing unit with
a built-in algorithm, a base fixed on a horizontal part, a vertical shaft guide

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mounted on the base, the two measuring devices measuring the distances
between the measuring devices and selected locations (such as A, B, C & D) on
the fillet and above the fillet, one device measuring at selected points the
distances from this device to the vertical part of the component joined to the
horizontal part by the fillet and the other device measuring the distances
between the measuring device and the horizontal surface (base) of the
component for all the selected points measured by the other device, feeding the
measured distances as data inputs in a processing unit and computing the fillet
dimensions through a built in algorithm in the processor and displaying the same
in a display device.
DESCRIPTION OF THE INVENTION
In this invention, an apparatus has been developed to measure the sizes of a
fillet weld. This apparatus is making use of two, length - measuring gauges fixed
along a vertical shaft. The out put of the gauges are displayed by a digital meter.
Also, the outputs can be fed to a micro controller based processing unit, which
will process the digital data and give the digital output of fillet weld sizes. The

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apparatus can also measure with ease, equal or unequal fillets, concave, convex
or flat profiles of the fillet and any angle between the surfaces joined by the
fillet. The length - measuring gauge can be either contact or non-contact type.
The proposed invention will be better understood from the following description
in which
Figure 1 shows schematically the essential features of the apparatus for the
measurement of the weld dimensions.
Fillet weld is made between the two parts (1) and (2)
A vertical guide (3) is mounted on a base (4) fixed on the part (2). The base will
be suitable for mounting on flat as well as curved surfaces.
Two, distance measuring devices (5) and (6) are mounted on a slide (7).
The weld (8) is made to join 1 and 2.
A, B, C and D are locations where measurements are made.
X1 and H1 are the distances measured at location A.

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The apparatus has two distance measuring systems. One measuring device (5)
will measure the distance from this measuring device to the vertical part of the
component, which is joined to the horizontal part by the fillet. This measuring
device will measure the distance at four points. One (A) of this will be above the
fillet, two (B & D) at the toes of the fillet and one (C) at the maximum concavity
or convexity on the fillet profile. The other measuring device (6) will measure
distance between the measuring device and the horizontal surface (base) of the
component for all the four points measured by the other measuring device.
The base of the apparatus is designed to enable setting the apparatus on a flat
surface or a curved surface. The base has a vertical shaft (3) on which the
distance measuring devices are suitably mounted on a slide (7). The slide moves
vertically up and down and it is operated manually to position the measuring
devices at suitable positions for carrying out the measurement at four points as
described above.
The output from the measuring devices in the digital form are fed to a
processing unit. The data input are processed using a mathematical program,
built-in to the processor. The output from the processor can be displayed
digitally through a display device. The processed data provided two leg lengths
and the actual throat of the fillet.

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The algorithm used the processor has been developed for the purpose of
measurement has the following mathematical characters for measuring vertical
and horizontal parts of the fillet through measuring distances between measuring
devices and the fillet for vertical and horizontal surface of the fillet.
Known input θ1
Measured Data: D1, D2, D3, D4, H1, H2, H3, H4
Computed Data: θ2, θ3, h1, h2, h3, h3, d1, d2, d3, d4, T, L1, L2
h1=H1 - D1 sin θ1 D1 = D1 cos θ1
h2= H2 - D2 sin θ1 d2 = D2 cos θ1
h3= H3 - D3 sin θ1 d3 = D3 cos θ1
h4 = H4 - D4 sin θ1 d4 = D4 cos θ1
θ2 = Tan-1 [(h1-h2)/(d2-d1)]
X1 = h2/tanθ2
L1 = h2/sinθ2
For positive d2-d1
L2 = X1 + (d2-d3)

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If d2-d1 is negative
L2 = (d2-d3)-X1
θ3 = Tan-1 [h2/(d2-d3)]
For metere & convex profile of the fillet
Throat T = L2sinθ3
Y = (h2-h4) - [(d2-d3) tanθ3]
Z = sin(90-θ3) Y
For concave fillet profile
Throat Tc =T - Z
The proposed invention is illustrated with the following practical example of
computed fillet dimensions of its two leg length and throat.
Example of Measured Data
For Measured Data set 1:
H1= 51.32
H2= 36.05
H3= 24.25
H4= 30.19

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D1= 52.64
D2= 56.11
D3= 48.50
D4= 53.39
Computed values:
Theta2=79.9622
Theta3=50.50
Concave Throat tc= 5.45
For Measured Data set 2:
H1=51.32
H2=37.85
H3=20.21
H4=32.27
Dl=52.64
D2=55.70
D3=40.41
D4=52.47

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Computed values:
Theta2=79.98
Theta3=37.06
Concave Throat tc=7.552
The invention as narrated herein should not be read as construed in a restrictive
manner as various modifications, alterations and adaptations are possible within
the scope and ambit of the invention as defined in the encompassed appended
claims.

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WE CLAIM
1. A contact or non-contact type digital gauge apparatus for measurement of
fillet weld surface profile comprising of:
- two measuring devices (5) and (6) mounted on a slide (7) and integrated
with a processing unit with a built-in algorithm,
a base (4) fixed on a horizontal part (2), a vertical shaft guide (3)
mounted on the base, the two measuring devices (5 & 6) measuring the
distances between the measuring devices and selected locations (such as
A, B, C & D) on the fillet (8) and above the fillet,
One device (5) measuring at selected points the distances from this device
to the vertical part of the component joined to the horizontal part by the
fillet (8) and the other device (6) measuring the distances between the
measuring device and the horizontal surface (base) of the component for
all the selected points measured by the other device (5),
feeding the measured distances as data inputs in a processing unit and
computing the fillet dimensions through a built in algorithm in the
processor and displaying the same in a display device.

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2. The digital gauge apparatus for measurement of fillet weld surface profile
as claimed in claim 1 wherein the location A is above the fillet, B & D at
the toes of the filtet, and C is at the maximum concavity or convexity of
the fillet profile.
3. The digital gauge apparatus as claimed in claim 1 wherein the devices (5)
and (6) are sensors, measuring the distances in digital form via a digital
meter.
4. The digital gauge apparatus as claimed in claims 1 and 3 wherein the
positions of the sensors (5 & 6) can be altered slidably through vertical
movement by the vertical guide (3).
5. The gauge apparatus as claimed in claim 1 wherein the base (4) is
suitably designed to set the measuring sensors on flat, cylindrical or any
other curved surface jobs.

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6. The gauge apparatus as claimed in the preceding claims wherein
measurement made from the distance sensors are fed as inputs into a
data processing unit inbuilt with an algorithm developed for the purpose,
to compute biaxial components of fillet dimensions measured at the toes
and top position of the fillet and display the measured dimensions of the
fillet in a display device.
7. The gauge apparatus as claimed in claim 6, wherein the vertical
components D1, D2, D3, D4 and horizontal components of the fillet and
angle of edge (θ2, θ3) are measured through a developed algorithm for
the purpose according to the mathematical steps of
Known input θ1
Measured Data: D1, D2, D3, D4, H1, H2, H3, H4
Computed Data: θ2, θ3, h1, h2, h3, h3, d1, d2, d3, d4, T, L1, L2
h1=H1 - D1 sin θ1 D1 = Di cos θ1
h2= H2 - D2 sin θ1 d2 = D2 cos θ1
h3= H3 - D3 sin θ1 d3 = D3 cos θ1
h4 = H4 - D4 sin θ1 d4 = D4 cos θ1

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θ2 = Tan-1 [(h1-h2)/(d2-d1)]
X1 = h2/tanθ2
L1 = h2/sinθ2
For positive d2-d1
L2 = X1 + (d2-d3)
If d2-d1 is negative
L2 = (d2-d3) - X1
θ3 = Tan-1 [h2/(d2-d3)]
For metere & convex profile of the fillet
Throat T = L2sinθ3
Y = (h2-h4) - [(d2-d3) tanθ3]
Z = sin(9O-θ3) Y
For concave fillet profile
Throat Tc =T - Z
8. The gauge apparatus as claimed in the preceding claims wherein the
sensors integrated with the processors enable to determine two leg
lengths, actual throat size, angle between the surfaces of the job
components joined by the fillet, angle of chamfer in a plate or pipe and
surface profile of fillet as a whole whether regular or irregular through the
built in algorithm with steps of mathematical calculation.

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9. A contact or non contact type digital gauge apparatus for measurement of
fillet weld surface profile as herein described and illustrated.
Dated this 22nd day of March 2007.

A contact or non-contact type digital gauge apparatus for measurement of fillet
weld surface profile comprising of two measuring devices (5) and (6) mounted
on a slide (7) and integrated with a processing unit with a built-in algorithm, a
base (4) fixed on a horizontal part (2), a vertical shaft guide (3) mounted on the
base, the two measuring devices (5 & 6) measuring the distances between the
measuring devices and selected locations (such as A, B, C & D) on the fillet (8)
and above the fillet, one device (5) measuring at selected points the distances
from this device to the vertical part of the component joined to the horizontal
part by the fillet (8) and the other device (6) measuring the distances between
the measuring device and the horizontal surface (base) of the component for all
the selected points measured by the other device (5), feeding the measured
distances as data inputs in a processing unit and computing the fillet dimensions
through a built-in algorithm in the processor and displaying the same in a display
device.

Documents:

00454-kol-2007-abstract.pdf

00454-kol-2007-claims.pdf

00454-kol-2007-correspondence others 1.2.pdf

00454-kol-2007-corrospond others.pdf

00454-kol-2007-description complete.pdf

00454-kol-2007-drawings.pdf

00454-kol-2007-form 18.pdf

00454-kol-2007-form 2.pdf

00454-kol-2007-form 3.pdf

00454-kol-2007-gpa.pdf

454-KOL-2007-(14-09-2011)-ABSTRACT.pdf

454-KOL-2007-(14-09-2011)-AMANDED CLAIMS.pdf

454-KOL-2007-(14-09-2011)-DESCRIPTION (COMPLETE).pdf

454-KOL-2007-(14-09-2011)-DRAWINGS.pdf

454-KOL-2007-(14-09-2011)-EXAMINATION REPORT REPLY RECIEVED.pdf

454-KOL-2007-(14-09-2011)-FORM 1.pdf

454-KOL-2007-(14-09-2011)-FORM 13.pdf

454-KOL-2007-(14-09-2011)-FORM 2.pdf

454-KOL-2007-(14-09-2011)-OTHERS.pdf

454-KOL-2007-FORM-27.pdf

abstract-00454-kol-2007.jpg


Patent Number 250428
Indian Patent Application Number 454/KOL/2007
PG Journal Number 01/2012
Publication Date 06-Jan-2012
Grant Date 03-Jan-2012
Date of Filing 22-Mar-2007
Name of Patentee BHARAT HEAVY ELECTRICALS LIMITED
Applicant Address REGIONAL OPERATIONS DIVISION (ROD), PLOT NO:9/1, DJBLOCK 3RD FLOOR, KARUNAMOYEE, SALT LAKE CITY, KOLKATA-700091, HAVING ITS REGISTERED OFFICE AT BHEL HOUSE, SIRI FORT, NEW DELHI-110049
Inventors:
# Inventor's Name Inventor's Address
1 PADMANABAN, KRISHNASWAMY WELDING RESEARCH INSTITUTE, BHARAT HEAVY ELECTRICALS LIMITED., TIRUCHIRAPALLI-620 014
2 SANTHAKUMARI, ARUNACHALAM WELDING RESEARCH INSTITUTE, BHARAT HEAVY ELECTRICALS LIMITED., TIRUCHIRAPALLI-620 014
3 MANOHARAN, SIVASANKARAN WELDING RESEARCH INSTITUTE, BHARAT HEAVY ELECTRICALS LIMITED., TIRUCHIRAPALLI-620 014
PCT International Classification Number G01G23/36; G01G23/18
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA