FIELD OF THE INVENTION
The present invention generally relates to an improved chamfering machine, more
particularly to an apparatus in a chamfering machine for edge preparation of work
piece or (elbows) used in welding the panels of steam generator.
BACKGROUND OF THE INVENTION
In the manufacturing of high pressure steam generators, panels are made in parts
to assemble at site during erection of the panels. In the above method, there are
eight panels are made at shop per steam generator. There are 375 tube bends
deformed into elbow, are required to connect two panels. These panel ends are to
be welded with about 3000 elbows to connect other panels using manual Tungsten
Inert Gas (TUG) welding. For TIG joints, the two ends of bends are to be chamfered
for perfect welding. In the chamfering machine, the minimum holding length 25mm
is used for holding in the machine for chambering. However, the tool holders are
used to hold and chamfer tube bend must be modified as minimum length and also
discussed in below existing art.
In the existing art, chamfering of bend tube portion used to connect panels of the
burner of a steam generator is discussed. The art teaches that, the modified tool
holder is designed to hold and chamfer the tube bends. The tool holder holds the
80mm length of tube bend. The problem discussed in the art is that the tool holder
holds the tube bends in lesser length than 80mm. To solve the issue a new tool
holder is manufactured and address the issue. The disadvantages of the known art
is that the new tool cannot hold the minimum length of elbow for chamfering
purpose.
Moreover, the deficiency in the existing manual grinding method is less quality
welding process and others. In the manual grinding operations, it causes a lot of
RT (Radiograph Testing) failures. The other major drawback associated with

manual chamfering/grinding process is longer duration of welding procedure as well
as the weld joint quality which significantly depends on human factor.
However, using the existing tool holder, the problems encountered previously are
eliminated and chamfering process is carried out successfully. But the existing tool
cannot addressed requirement of chamfered elbows used to weld the panels in the
steam generator.
Therefore, there is a need to modify the chamfering machine in such a manner,
that the drawbacks of conventional chamfering machines are addressed.
OBJECTS OF THE INVENTION
It is therefore the object of the invention to overcome the aforementioned and
other drawbacks existing in prior art machine.
The primary object of the present invention, is to provide an apparatus in a
chamfering machine, for chamfering the short arm length of elbows.
Another object of invention, is to provide the edge preparation of the short arm
elbows to weld in the panel assemblies of steam generator.
Yet another object of the present invention, is to provide shorten length of a top
support clamp and bottom support clamp, to hold the short arm elbow during
chamfering;
Still another object of the present invention, is to achieve huge number of exact
length of elbows for welding the panels of steam generator in very less time which
save in manpower and cost.

SUMMARY OF THE INVENTION
One or more drawbacks of conventional machine are overcome by placing an
apparatus in a chamfering machine and additional advantages are provided through
the apparatus and a method as claimed in the present disclosure. The present
invention generally discloses an apparatus in a chamfering machine for machining
elbows used for connecting steam generator panels. The proposed apparatus in a
chamfering machine is used for chamfering the elbow in such a manner that the
modified elbows can be perfectly used for connecting panels of steam generator.
In the present invention, the apparatus is incorporated on a chamfering machine
which constitutes a first tool holder (smaller diameter tool holder), a second tool
holder(larger diameter tool holder), at least three numbers of allen screws and
modified length of both top support clamp and bottom support clamp to hold the
work piece or elbow for chamfering purpose.
In the embodiment of the present invention, both the tool holders are selected to
make “step turning” and “step boring” in such a manner, so that the small tool
holder is fitted inside the larger tool holder. The larger diameter tool holder and
small diameter tool holder are assembled together by using at least three number
allen screws circumferentially with an equal spacing for rigidify purpose.
In an embodiment of the disclosed invention, the assembly of the larger and smaller
tool holder is inserted in to the chamfering machine to ensure a perfect rotation
transfer of the cutting tool at the end of the work piece or elbow. Moreover, the
top clamp is used for holding the elbow, and the length of the top clamp is
shortened to 15mm from 42mm. In the same way, length of the bottom clamp is
shortened to 15mm from 40mm. The elbow is fixed between the top and bottom

clamps. The improved tool holder is therefore, enabled to carry the conventional
cutting tool for chamfering the elbow edge to its desired arm length of 15mm.
In a feature of the present invention, by this method for constructing an improved
chamfering apparatus, the edge preparation time is greatly reduced to chamfer
large quantity of elbows used in subsequent welding. By using this method, the
quality is also enhanced and productivity is also increased in the manufacturing of
the panels of steam generators. The entire method saves the cost of making huge
number of elbows for connecting panels of steam generator.
Various objects, features, aspects and advantages of the inventive subject matter
will become more apparent from the following detailed description of preferred
embodiments, along with the accompanying drawing figures in which like numerals
represents like components.
It is to be understood that the aspects and embodiments of the disclosure described
above may be used in any combination with each other.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The illustrated embodiments of the subject matter will be best understood by
reference to the drawings, wherein like parts are designed by like numerals
throughout. The following description is intended only by way of example, and
simply illustrates. Certain selected embodiments of improved chamfering machine
that are consistent with the subject matter as claimed herein, wherein:

Figure-1- illustrates the apparatus in a chamfering machine with a tool holder with
modified top clamp along with the work piece in position according to the present
invention.
Figure-2- illustrates the tool holder with chamfering tool according to prior art.
Figure-3- illustrates the top clamp used for fixing the work piece or (elbow) in the
machine according to the prior art.
Figure-4- illustrates the shorter length top clamp used in the chamfering machine
for fixing the work piece during chamfering according to the present invention.
Figure-5- illustrates the smaller diameter of the tool holder both in isometric view
and elevation according to the present invention.
Figure-6- illustrates the larger diameter of the tool holder both in isometric and
elevation views, according to the present invention.
Figure-7- illustrates the shorter length of bottom clamp holder used in the
chamfering machine for fixing the work piece during chamfering according to the
present invention.
The figures depict the embodiments of the disclosure for purposes of illustration
only. One skilled in the art will readily 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.
DETAILED DESCRIPTION OF THE INVENTION
While the embodiments of the disclosure are subject to various modifications of the
chamfering machine to chamfer the work piece or elbow, used for connecting
panels of the steam generator. The figure-1 shows the detailed diagram of an
apparatus in a chamfering machine. The proposed apparatus in chamfering
machine shown in figure-1, includes a chamfering machine, incorporated with a

tool holder assembly (5) and top support clamp (7) and bottom support clamp (14)
to hold the work piece or elbow (13). Both the tool holders are connected with at
least three allen screws (12). The prior art tool holder with chamfering tool is
shown in figure-2.
As shown in figure -5, a first tool holder (small diameter tool holder) (4) is provided
for step-turning (10, 11) in the opposite end of the same tool holder. As shown in
figure-6, a second tool holder (larger diameter tool holder) (3) is provided for
step-boring (8, 9). The step-turning and step-boring of the tool holders (3,4) are
carried out in such a manner that the step turned portion (11, 10) is fitted with the
bore holes (9, 8). The assembly of the first and second tool holders (3, 4) are then
fitted by using at least three allen screws (12). Three allen screws are connected
at three equally spaced locations along the outer diameter of the tool holder as
shown in the Fig-1 . The first tool holder (4) and the second tool holder (3) are
fitted together via said three allen screws (12), out of that, two allen screws (12)
are spaced equally on the smaller tool holder (4), and third allen screw (12) on the
larger tool holder (3) as shown in fig-1. Referring to figure-1, the tool holder
assembly (5), is inserted in the chamfering machine (1).
According to the present invention as illustrated in fig-4 and fig-7, the length of the
top clamp (7) is shortened from 42mm to 15mm, which is assembled in the
chamfering machine (1) as shown in fig-4. The existing top clamp, used for fixing
the work piece/ elbow (13) in the machine, is shown in the figure -3. The length of
the top clamp (7) is much shortened so that it can hold the work piece (13) with
the same length. Again, referring to fig-7, the length of the bottom clamp (14) is
shortened to 15mm from 40mm and assembled on the chamfering machine (1). By
this arrangement, the existing tool holder assembly (5) with the help of the modified

top support clamp (7) and modified bottom support clamp (14), it is possible to
chamfer the work piece or elbow (13) having minimum arm length of 15mm.
Further, the method for forming an apparatus for chamfering elbows, according to
the present invention, comprises the steps of: forming a tool holder assembly (5)
by fitting the first tool holder into the second tool holder in such a manner that the
step turned portion (10,11) fits with the corresponding bore holes (8,9) as shown
in fig-5 and fig-6 and fig-1. The method also includes assembling the tool holder
assembly(5) into the chamfering machine and also assembling the top support
clamp(7) and bottom support clamp(14) onto the chamfering machine after
shortening the length of top support clamp (7) and bottom support clamp (14) from
the normal lengths. The first tool holder (4) and the second tool holder (3) are
fitted together via at least three allen screws (12), wherein, two allen screws (12)
are spaced equally on the first tool holder (4) and the third allen screw (12) is
placed on the second tool holder (3).The tool holder assembly (5) is assembled into
the chamfering machine. The method also includes that by reducing length of both
the top clamp from 42mm to 15mm and the bottom clamp from 40mm to 15mm to
hold the elbow of minimum length of 15mm for chamfering the edge.
Further, by the method of chamfering machine operation, huge no of elbows
having shorter length as 15mm are made with less time and hence substantial
saving in terms of manpower and cost. Thereby, the productivity is enhanced and
the drawbacks said in the background of the invention are eliminated.

WE CLAIM:
1. An apparatus in a chamfering machine for chamfering elbows used for
connecting panels of a steam generator, the chamfering machine comprising
at least a tool holder assembly (5), the apparatus comprising:-
a first tool holder (4) configured with step turnings (10,11) on an end
surface, a second tool holder (3) configured with bore holes (8,9) on
an end surface such that the step turned portion (10, 11) fits perfectly
on the corresponding bore holes (8,9), wherein the diameter of the
first tool holder (4) is smaller than the diameter of the second tool
holder (3), and
a top support clamp (7) and a bottom support clamp (14)
assembled onto the chamfering machine, wherein the top support
clamp and the bottom support clamp is shortened in length from their
normal lengths.
2. The apparatus in a chamfering machine as claimed in claim 1, wherein
the first tool holder (4) and the second tool holder (3) are fitted together
via at least three allen screws (12), and wherein two out of the said at
least three allen screws (12) are spaced equally on the first tool holder
(4), and the third allen screw (12) is placed on the second tool holder
(3).
3. The apparatus in a chamfering machine as claimed in claim 1, wherein
length of the top support clamp (7) is shortened from 42 mm to 15 mm.

4. The apparatus in a chamfering machine as claimed in claim 1, wherein
length of the bottom support clamp (14) is shortened from 40 mm to 15
mm.
5. The apparatus in a chamfering machine as claimed in claim 1, wherein
the apparatus is enabled to machine the elbow having a minimum arm
length of 15 mm.
6. A method for forming an apparatus for chamfering elbows used in
connecting panels of a steam generator, the method comprising:
forming a tool holder assembly (5), by fitting, a first tool holder (4)
which is configured with step turning (10, 11) on an end surface, a
second tool holder (3) configured with bore holes (8,9) on an end
surface, in such a manner that the step turned portion (10,11) fits
with the corresponding bore holes (8,9);
assembling the tool holder assembly (5) into the chamfering machine;
and
assembling a top support clamp(7) and a bottom support clamp(14)
onto the chamfering machine after shortening the length of the top
support clamp (7) and bottom support clamp (14) from the normal
lengths.

7. The method as claimed in claim 6, wherein the first tool holder (4) and
the second tool holder (3) are fitted together via three allen screws (12),
wherein, two allen screws (12) are spaced equally on the first tool holder
(4) and the third allen screw (12) is placed on the second tool holder (3).