FIELD OF THE INVENTION
This invention relates to a Digital apparatus for measuring various
dimensions of a completed fillet weld. More particularly, the invention relates to
a contact or non-contact type digital apparatus for measurement of fillet weld
surface profile
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.
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.
WIPO-publication W00221071 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.
OBJECTS OF THE INVENTION
it is therefore, an object of the present invention to propose a contact or non-
contact type digital measurement apparatus for measurement of fillet weld
surface profile.
Another object of the invention is to propose a contact or non-contact type
digital measurement apparatus for measurement of fillet weld surface profile,
which is capable 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 propose a contact or non-contact type
digital measurement apparatus for measurement of fillet weld surface profile,
which is enabled to measure the angle of edge preparation.

A further object of the invention is to propose a measurement method which
carries-out the measurement through non-contact measurement device by using
a micro-computer based processor with simple algorithm.
SUMMARY OF THE INVENTION
According to the invention there is provided a contact or non-contact type digital
gauge apparatus for measurement 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
mounted on the base, the two measuring devices measuring the distances
between the measuring devices and selected locations (such as A, B, C and 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.
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
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.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The proposed invention will be better understood from the following description
in which
Figure 1(a) - shows schematically the apparatus of the invention
Figure 1(b) and 1(c) - each shows the measurement of fillet profile flat or
angular.
DETAIL DESCRIPTION OF THE INVENTION
As shown in figure - 1, the component to be measured comprises of two parts
(1), (2), connected by a fillet weld (8).
The measuring apparatus comprises of a vertical guide (3), mounted on a base
(4). 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
measuring devices can be a laser beam based for non contact type, linear volt
differential transformer for contact type.

Measuring device A can be set at desired angle and clamped in position with a
first screw (9). The slide is moved vertically by a second screw (10).
A, B, C and D are locations where measurements are made.
X1 and H1 are the distances measured at location A.
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 and 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 measring 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.
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.



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:



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.

WE CLAIM
1. A contact or non-contact type digital apparatus for measurement of fillet
weld surface profile, comprising:
- two measuring device (5,6) mounted on a slide (7) and integrated with a
micro-computer based processor;
- a base (4) fixed on a horizontal member (2) to be welded to a vertical
member (1), the first measuring device (6) is disposed at a height (H)
along a vertical shaft guide (3) fixed to the base (4), wherein the first
measuring device (6) attached to a first side of the slide (7), the second
measuring device (5) is located at an angle on a second side of the slide
(7);
- the second measuring device (5) measuring at selected points the
distances from this device along the vertical member (1) and the first
measuring device (6) measuring the distances between the device along
the horizontal member (2) for all said selected points measured by the
second device (5),
- a fillet joint (8) produced through welding of the horizontal and vertical
members (2,1), and having at least four locations (A,B,C,D), the first
location (A) is selected at a height above the fillet join on the vertical
member (1), the second and fourth locations (B,D) at the toes of the fillet
joint on the vertical and horizontal members (1,2) respectively, and the
third location (c) at one of the maximum concavity and convexity of the
fillet profile;
- the processor receiving the measured digital data from the devices (5,6),
and processing the data to determine fillet weld surface profile; and

- a display unit operably connected to the processor to display the profile.
2. The digital apparatus as claimed in claim 1 wherein the devices (5)
and (6) are sensors, measuring the distances in digital form via a digital
meter.
3. The digital apparatus as claimed in claims 1 or 2, wherein the
positions of the sensors (5 and 6) can be altered slidably through vertical
movement by the vertical guide (3).
4. The digital apparatus as claimed in claim 1 wherein the base (4) is
configured to set the measuring sensors on flat, cylindrical or any
other curved surface jobs.
5. The digital apparatus as claimed in any of the preceding claims, wherein
the measurement made from the distance sensors (5,6) are fed as inputs
into the processor inbuilt with an algorithm, and wherein the processor is
enabled 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.
6. The digital apparatus as claimed in claim 5, wherein the vertical
components D1, D2, D3, D4 and horizontal components of the fillet and
angle of edge (92, 03) are measured through a developed algorithm for
the purpose according to the mathematical steps of

The apparatus as claimed in any of the preceding claims, wherein the
processor is enabled based on the data received from the devices (5,6) to
determine two leg lengths, actual throat size, angle between the surfaces
of the job components joined by the fillet (8), angle of chamfer in a plate
or pipe and surface profile of the fillet (8) as a whole whether regular or
irregular shaped.
8. A contact or non contact type digital apparatus for measurement of
fillet weld surface profile as herein described and illustrated with reference
to the accompanying drawings.

ABSTRACT

TITLE : "A CONTACT OR NON-CONTACT TYPE DIGITAL APPARATUS FOR
MEASUREMENT OF FILLET WELD SURFACE PROFILE"
A contact or non-contact type digital apparatus for measurement of fillet weld
surface profile, comprising two measuring device (5,6) mounted on a slide (7)
and integrated with a micro-computer based processor; a base (4) fixed on a
horizontal member (2) to be welded to a vertical member (1), the first measuring
device (6) is disposed at a height (H) along a vertical shaft guide (3) fixed to the
base (4), wherein the first measuring device (6) attached to a first side of the
slide (7), the second measuring device (5) is located at an angle on a second
side of the slide (7); he second measuring device (5) measuring at selected
points the distances from this device along the vertical member (1) and the first
measuring device (6) measuring the distances between the device along the
horizontal member (2) for all said selected points measured by the second device
(5), fillet joint (8) produced through welding of the horizontal and vertical
members (2,1), and having at least four locations (A,B,C,D), the first location (A)
is selected at a height above the fillet join on the vertical member (1), the
second and fourth locations (B,D) at the toes of the fillet joint on the vertical and
horizontal members (1,2) respectively, and the third location (c) at one of the
maximum concavity and convexity of the fillet profile; he processor receiving the
measured digital data from the devices (5,6), and processing the data to
determine fillet weld surface profile; and a display unit operably connected to the
processor to display the profile.