FIELD OF INVENTION
[001] The present invention relates to a slip-free and insulated filler wire pinch roller
mechanism for orbital Tungsten Inert Gas (TIG) welding applications.
BACKGROUND OF THE INVENTION
[002] Manufacturing of pressure part components of thermal boiler require huge
quantum of welding. Two straight tubes are joined together using Metal Inert Gas
(MIG) or Tungsten Inert Gas (TIG) welding process. These welding operations are
carried out in various types of automated welding stations. Orbital TIG welding
machines are a specialized application of welding whereby the arc is rotated
mechanically through 360° around a static work piece, an object such as a tube, in a
continuous process. This machine is employed for correcting welding defects in joints
welded by either automated MIG process or manual arc welding process. The orbital
welding process is completely automated which runs with little intervention from the
operator. As such, the process is used for high quality repeatable welding. Orbital
welding systems use TIG welding to perform the automatic circumferential welds it
carries out.
[003] The automatic machine perform welds better than human thus allowing for
better quality welds. Apart from creating better welds, due automatic operation it
improves the safety of a welding operation. While the machine is performing the
welds, a welder is not being exposed to the dangers of welding. Here, the tubes are
clamped in place and an orbital weld head rotates an electrode and electric arc around
the weld joint to make the required weld, unlike in other automated machines wherein
the arc is stable and the tubes rotate. An orbital welding system consists of a power
supply and an orbital weld head.

[004] The power supply/control system supplies and controls the welding parameters
according to the specific weld program created or recalled from memory. It provides
the control parameters, the arc welding current, the power to drive the motor in the
weld head and switches the shield gas(es) on/off as necessary. Orbital weld heads are
fully enclosed and provide an inert atmosphere chamber that surrounds the weld joint.
Even though the controller is carrying out welds automatically, however frequent
complaints are reported from this machine. The major complaints are joint rejection,
water leakage, pendent communication error, feedback and gas flow etc.
[005] The entire process included in orbital TIG welding are tube loading, edge
preparation, tube edge aligning and head fixing, welding arc feeding/wire feeding,
welding stop, radiography test checkup, if joint is found OK then it is sent for coil
formation and then to shipping, but if joint is not found OK it gets rejected and the
entire process need to be restarted again. Hence, the rework on rejected tubes/pipes
causes reduction in productivity, production cost increases and increases the cycle
time, due to which on time delivery is not possible. In a survey conducted on joint
rejection for a period of 6 months, 21% rejection in joints was observed. Initial analysis
showed that insufficient filler wire was the cause of the problem.
[006] After collecting various data, it was established that filler wire with higher
Chromium (Cr) content increases its hardness and as the hardness increases, the slip
also increases. This slip causes insufficient filler wire feeding into the welding pool,
thereby resulting in joint rejection. “Pinch roller” mechanism, which is responsible for
feeding the wire at appropriate speed and quantity, in the current design was root cause
of the problem.
[007] Only solution to reducing this large amount of joint rejection is by replacing
the existing pinch roller arrangement. The existing the pinch roller was plain and

smooth and also the pinch roller housing was made of a grade of Teflon. Additionally,
the entire pinch roller arrangement does not have any pressure adjusting mechanism
in order to regulate the wire feeding during welding. This results in slip during welding
ultimately resulting in joint rejection.
[008] In the prior arts, filler wire feeding is achieved by various combinations of
drive rollers and guide rollers. These systems have employed either one of each type
rollers or two of each depending on the application or mounting location. However, in
all cases, the drive roller(s) responsible for providing appropriate pressure for ensuring
feeding of filler wire into the weld pool is/are plain in nature which provides difficulty
in feed adjustment during welding and is bound to slip.
[009] US4009360A titled “Orbital welding apparatus”. This patent discloses wire
feed mechanism, which is mounted effectively on the drive-member, comprises drive
rollers which are coupled together by gears, and respective pressure rollers. The
apparatus further comprises employs four rollers – two drive and two pressure rollers,
which adds to the complexity of feed adjustments. However, the plain rollers are
bound to slip while feeding the filler wire due to variations in hardness.
[0010] US4038509A titled “Orbital welding apparatus” discloses a differential
rotation orbital welding apparatus. This patent discloses a wire feed mechanism
mounted on the block that includes a drive roller driven by bevel gears and cooperating
with a grooved roller. The filler wire is drawn off the spool by the rollers and fed to
the weld zone adjacent the tip of the welding torch electrode. Further a grooved roller
is used for guiding the wire direction but still employs a plain drive roller which is
susceptible to slippage.
[0011] “US9527153B2” titled “Camera and wire feed solution for orbital welder
system” discloses about a system related to a camera device and wire guide system

that includes a bracket for a wire guide and a camera device. The bracket aligns the
camera device to aim on a position of a welding zone for an orbital welding system.
This patent describes about visibility of welding thorough camera and adjustment of
wire location to reduce obstruction of view of welding. However, the orbital welder
system still employs a plain drive roller and grooved guide roller which does not
address the issue of slippage of filler wire during welding.
[0012] None of the above cited prior art herein discusses the issues related to a slip-
free wire feeding mechanisms for orbital welding applications.
[0013] The present invention is directed to overcoming one or more problems set forth
above and/or other problems associated with known system of slip-free filler wire
feeding.
OBJECTS OF THE INVENTION
[0014] It is therefore, the principal object of the present invention to provide a pinch
roller mechanism for feeding filler wire into the welding pool in Tungsten Inert Gas
(TIG) welding process.
[0015] Another objective of the invention is to ensure feeding of filler wire without
any slip and in appropriate quantity to ensure welding quality and reduce joint
rejection.
[0016] Yet another objective of the invention is to ensure proper isolation between
positive and negative supplies in TIG welding as the filler wire is in constant contact
with the machine body and weld pool.

[0017] Further objective of the invention is to provide facility for easy adjustment of
wire feeding during the welding process in the form of pressure adjustment
mechanism.
[0018] Another objective of the invention is to reduce rejections in welding due to
improper feeding of filler wire and improve productivity.
[0019] These and other objects and advantages of the present subject matter will be
apparent to a person skilled in the art after consideration of the following detailed
description taken into consideration with accompanying drawings in which preferred
embodiments of the present subject matter are illustrated.
SUMMARY OF THE INVENTION
[0020] This summary is provided to introduce concepts related to a system for
facilitating a slip-free wire feeding mechanisms for orbital welding applications
[0021] The present disclosure relates to a system for facilitating orbital tungsten inert
gas (TIG) welding which comprises a geared roller with teeth having an aperture for
fixing an insulator and a mounting shaft. The insulator provides isolation between a
positive and a negative supplies in a welding. A pinch roller housing assembly with a
mounting platform and at least one clamping arm configured to clamp the geared roller
at appropriate position for wire feeding.
[0022] In an aspect the system further comprises a pinch roller pressure adjustment
element disposed on a L-shaft with coarse and fine pressure adjustment screws to
adjust the pressure on the filler wire. The pinch roller housing assembly is mounted on
the L-shaft which is fitted to the machine body.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0023] It is to be noted, however, that the appended drawings illustrate only typical
embodiments of the present subject matter and are therefore not to be considered for
limiting of its scope, for the invention may admit to other equally effective
embodiments. The detailed description is described with reference to the
accompanying figures. In the figures, a reference number identifies the figure in which
the reference number first appears. The same numbers are used throughout the figures
to reference like features and components. Some embodiments of system or methods
or structure in accordance with embodiments of the present subject matter are now
described, by way of example, and with reference to the accompanying figures, in
which:
[0024] FIG. 1 is an exploded view of a system with a gear roller, pinch roller housing
assembly, mounting platform, and pinch roller pressure adjustment element in an
embodiment of the present invention.
[0025] The figures depict embodiments of the present subject matter for the purposes
of illustration only. A person skilled in the art will easily recognize from the following
description that alternative embodiments of the structures and methods illustrated
herein may be employed without departing from the principles of the disclosure
described herein.
DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE
PRESENT INVENTION WITH REFERENCE TO THE ACCOMPANYING
DRAWINGS

[0026] While the embodiments of the disclosure are subject to various modifications
and alternative forms, specific embodiment thereof have been shown by way of
example in the figures and will be described below. It should be understood, however,
that it is not intended to limit the disclosure to the particular forms disclosed, but on
the contrary, the disclosure is to cover all modifications, equivalents, and alternative
falling within the scope of the disclosure.
[0027] The terms “comprises”, “comprising”, or any other variations thereof used in
the disclosure, are intended to cover a non-exclusive inclusion, such that a device,
system, assembly that comprises a list of components does not include only those
components but may include other components not expressly listed or inherent to such
system, or assembly, or device. In other words, one or more elements in a system or
device proceeded by “comprises… a” does not, without more constraints, preclude the
existence of other elements or additional elements in the system or device.
[0028] The present invention relates to a system (100) for facilitating orbital Tungsten
Inert Gas (TIG) welding.
[0029] FIG. 1 illustrates the exploded view of the system (100) with various
components. The system (100) comprises with a gear roller (1), a pinch roller housing
assembly (6), a mounting platform (7), and a pinch roller pressure adjustment element
(10) in an embodiment of the present invention.
[0030] Referring to FIG. 1, in one embodiment the gear roller (1) is used to provide
enhanced grip on the feed wire and to reduce the slip. The gear roller (1) consists of
‘n’ number of teeth (2), which are suitably configured at the edges to avoid making
dents on the filler wire. With application of appropriate pressure, bending of the wire
is avoided during use. In a preferred embodiment the system (100) could be fixed on
the existing grooved guide roller available on the machine. A plurality of teeth (2) are

configured according to pressure requirements and hardness of the filler wire. In one
embodiment the gear roller (1) could carry “N number” of teeth (2) which are
preferably formed on the edge portion. The geared roller (1) with teeth (2) having an
aperture (3) for fixing an insulator (4). The insulator (4) provides electrical isolation
between a negative supply on the welding torch and a positive supply in a welding
work. The insulator (4) is provided as the filler wire is in constant contact with the
machine body and the weld pools. The insulation between the positive and the negative
supplies (i.e.) polarities ensures safety to the operator.
[0031] In one embodiment the gear roller (1) is insulated and mounted to a pinch roller
housing assembly (6) using a metal mounting shaft (5). In a preferred embodiment the
pinch roller housing assembly (6) is made up of stainless steel to ensure ruggedness
and rigidity. The pinch roller housing assembly (6) further comprises a mounting
platform (7) and at least one clamping arm (8) configured for fixing the shaft (5). The
shaft (5) is mounted through the holes on the at least one clamping arm (8) and the
mounting platform (7) is used to configure the pinch roller housing assembly (6) along
with the insulated gear roller (1) to the L-shaft (9). In a preferred embodiment the L-
shaft is made of metal, consists of provisions for fixing two pressure adjusting screws
(11, 12). The two pressure adjustment screws (11, 12) combine together to form the
pressure adjustment element (10). The pinch roller pressure adjustment element (10)
disposed on the L-shaft (9) with coarse pressure adjustment screw (11) and fine
pressure adjustment screw (12) to adjust the pressure on the filler wire during welding
in order to ensure a slip-free feeding to the weld pool.
[0032] In one embodiment the coarse pressure adjustment screw (11) moves the gear
roller between 1 mm to 2 mm in up/down direction which adjusts the pressure on the
filler wire. The fine pressure adjustment screw (12) is used to move the gear roller
between 0.1 mm to 0.5 mm which in turn used for pressure adjustment during welding.
In a preferred embodiment the pinch roller housing assembly (6) is mounted over the

L-shaft (9). In one embodiment the pinch roller housing assembly (6) is mounted on
the L-shaft (9) which is fitted to the existing machine body. The filler wire passes
smoothly and without slippage into the weld pool by using the pinch roller pressure
adjustment element (10) thereby reducing rejection of welding joints.
[0033] In one embodiment the system (100) configured to reduce rejection of welding
joints from 21% to 3%. In a preferred embodiment the system (100) configured to
operate as a slip-free and insulated filler wire pinch roller mechanism for orbital
tungsten inert gas (TIG) welding applications. In the system (100), the insulated filler
wire pinch roller mechanism is suitable for tungsten inert gas (TIG) welding
applications which uses automatic wire feeders. The system (100) provides proper
insulation between the positive and negative supplies in the machine and ensures
safety to the operator. The system (100) provides a slip-free filler wire feeding that
ensures reduction in rejection of welding joint and improves productivity.
[0034] It should be noted that the description and figures merely illustrate the
principles of the present subject matter. It should be appreciated by those skilled in the
art that conception and specific embodiment disclosed may be readily utilized as a
basis for modifying or designing other structures for carrying out the same purposes
of the present subject matter. It should also be appreciated by those skilled in the art
that by devising various arrangements that, although not explicitly described or shown
herein, embody the principles of the present subject matter. Furthermore, all examples
recited herein are principally intended expressly to be for pedagogical purposes to aid
the reader in understanding the principles of the present subject matter and the
concepts contributed by the inventor(s) to furthering the art and are to be construed as
being without limitation to such specifically recited examples and conditions. The
novel features which are believed to be characteristic of the present subject matter,
both as to its organization and method of operation, together with further objects and

advantages will be better understood from the following description when considered
in connection with the accompanying figures.
[0035] These and other advantages of the present subject matter would be described
in greater detail with reference to the following figures. It should be noted that the
description merely illustrates the principles of the present subject matter. It will thus
be appreciated that those skilled in the art will be able to devise various arrangements
that, although not explicitly described herein, embody the principles of the present
subject matter and are included within its scope. The present invention will now be
described more specifically with reference to the following specification.
[0036] It should be noted that the description and figures merely illustrate the
principles of the present subject matter. It should be appreciated by those skilled in the
art that conception and specific embodiment disclosed may be readily utilized as a
basis for modifying or designing other structures for carrying out the same purposes
of the present subject matter. It should also be appreciated by those skilled in the art
that by devising various arrangements that, although not explicitly described or shown
herein, embody the principles of the present subject matter and are included within its
spirit and scope. Furthermore, all examples recited herein are principally intended
expressly to be for pedagogical purposes to aid the reader in understanding the
principles of the present subject matter and the concepts contributed by the inventor(s)
to furthering the art and are to be construed as being without limitation to such
specifically recited examples and conditions.
[0037] The novel features which are believed to be characteristic of the present subject
matter, both as to its organization and method of operation, together with further
objects and advantages will be better understood from the following description when
considered in connection with the accompanying figures.

[0038] Although embodiments for the present subject matter have been described in
language specific to package features, it is to be understood that the present subject
matter is not necessarily limited to the specific features described. Rather, the specific
features and methods are disclosed as embodiments for the present subject matter.
Numerous modifications and adaptations of the system/device of the present invention
will be apparent to those skilled in the art, and thus it is intended by the appended
claims to cover all such modifications and adaptations which fall within the scope of
the present subject matter.
[0039] It will be understood by those within the art that, in general, terms used herein,
and especially in the appended claims (e.g., bodies of the appended claims) are
generally intended as “open” terms (e.g., the term “including” should be interpreted as
“including but not limited to,” the term “having” should be interpreted as “having at
least,” the term “includes” should be interpreted as “includes but is not limited to,”
etc.). It will be further understood by those within the art that if a specific number of
an introduced claim recitation is intended, such an intent will be explicitly recited in
the claim, and in the absence of such recitation no such intent is present. For example,
as an aid to understanding, the following appended claims may contain usage of the
introductory phrases “at least one” and “one or more” to introduce claim recitations.
However, the use of such phrases should not be construed to imply that the
introduction of a claim recitation by the indefinite articles “a” or “an” limits any
particular claim containing such introduced claim recitation to inventions containing
only one such recitation, even when the same claim includes the introductory phrases
“one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a”
and/or “an” should typically be interpreted to mean “at least one” or “one or more”);
the same holds true for the use of definite articles used to introduce claim recitations.
In addition, even if a specific number of an introduced claim recitation is explicitly
recited, those skilled in the art will recognize that such recitation should typically be
interpreted to mean at least the recited number (e.g., the bare recitation of “two

recitations,” without other modifiers, typically means at least two recitations, or two
or more recitations). Furthermore, in those instances where a convention analogous to
“at least one of A, B, and C, etc.” is used, in general such a construction is intended in
the sense one having skill in the art would understand the convention (e.g., “a system
having at least one of A, B, and C” would include but not be limited to systems that
have A alone, B alone, C alone, A and B together, A and C together, B and C together,
and/or A, B, and C together, etc.). In those instances where a convention analogous to
“at least one of A, B, or C, etc.” is used, in general such a construction is intended in
the sense one having skill in the art would understand the convention (e.g., “a system
having at least one of A, B, or C” would include but not be limited to systems that
have A alone, B alone, C alone, A and B together, A and C together, B and C together,
and/or A, B, and C together, etc.). It will be further understood by those within the art
that virtually any disjunctive word and/or phrase presenting two or more alternative
terms, whether in the description, claims, or drawings, should be understood to
contemplate the possibilities of including one of the terms, either of the terms, or both
terms. For example, the phrase “A or B” will be understood to include the possibilities
of “A” or “B” or “A and B.”
[0040] It will be further appreciated that functions or structures of a plurality of
components or steps may be combined into a single component or step, or the
functions or structures of one-step or component may be split among plural steps or
components. The present invention contemplates all of these combinations. Unless
stated otherwise, dimensions and geometries of the various structures depicted herein
are not intended to be restrictive of the invention, and other dimensions or geometries
are possible. In addition, while a feature of the present invention may have been
described in the context of only one of the illustrated embodiments, such feature may
be combined with one or more other features of other embodiments, for any given
application. It will also be appreciated from the above that the fabrication of the unique
structures herein and the operation thereof also constitute methods in accordance with

the present invention. The present invention also encompasses intermediate and end
products resulting from the practice of the methods herein. The use of “comprising”
or “including” also contemplates embodiments that “consist essentially of” or “consist
of” the recited feature.
[0041] Although embodiments for the present subject matter have been described in
language specific to structural features, it is to be understood that the present subject
matter is not necessarily limited to the specific features described. Rather, the specific
features and methods are disclosed as embodiments for the present subject matter.
Numerous modifications and adaptations of the system/component of the present
invention will be apparent to those skilled in the art, and thus it is intended by the
appended claims to cover all such modifications and adaptations which fall within the
scope of the present subject matter.

WE CLAIM:
1. A system (100) that facilitates orbital tungsten inert gas (TIG) welding comprises:
a geared roller (1) with teeth (2) having an aperture (3) for fixing an insulator (4)
and a mounting shaft (5), the insulator (4) provides isolation between a positive and a
negative supplies in a welding and
a pinch roller housing assembly (6) with a mounting platform (7) and at least one
clamping arm (8) configured to clamp the geared roller (1) at appropriate position for
wire feeding.
2. The system (100) as claimed in claim 1, wherein the pinch roller housing assembly
(6) is mounted on a L-shaft (9) which is fitted on the machine body.
3. The system (100) as claimed in claim 1, further comprises a pinch roller pressure
adjustment element (10) disposed on the L-shaft (9) with coarse pressure
adjustment screw (11) and fine pressure adjustment screw (12) to adjust the
pressure on the filler wire during welding in order to ensure a slip-free feeding to
the weld pool.
4. The system (100) as claimed in claim 1, configured to reduce rejection of welding
joints from 21% to 3%.
5. The system (100) as claimed in claim 1, configured to operate as a slip-free and
insulated filler wire pinch roller mechanism for orbital tungsten inert gas (TIG)
welding applications.

6. The system (100) as claimed in claim 5, wherein insulated filler wire pinch roller
mechanism is suitable for tungsten inert gas (TIG) welding applications which uses
automatic wire feeders.