FIELD OF INVENTION
The present invention relates to a tool clamping device for horizontal boring
machine. More particularly, the invention relates to a tool clamping device to
adapt indigenous tools on the same machine in the event of original and special
foreign tools being exhausted.
BACKGROUND OF THE INVENTION
A horizontal boring machine of the plant is an important and critical machine
carrying out various machining operations like boring, facing, grooving,
threading, recessing, drilling, reaming etc. for different generator components up
to 500 MW. Component machined on this machine are generator rotor shaft,
exciter shaft, end shield, stator body, stator frame, baffle ring, generator core
bar etc. Machining operations on these components are carried out by using
different sizes of tools and cutters depending upon requirement of size and
surface finish. Some of the heavy components are directly placed on machine
bed, some components require block to raise their height and some components

like rotor shaft are placed on rollers and 'V' blocks and some components are
loaded on rotary table of the machine.
All the component being heavy, lot of care and safety precautions are taken
during handling and setting on machine. Efforts are made to complete almost all
the machining operation in the same setting which requires wide range of
tooling.
So far the above mentioned horizontal boring machine was run with imported
special tooling till these special tooling got exhausted due to constant wear and
tear. It made the special tooling attachments that hold the tool for machining
operation redundant due to non-availability of imported special tooling in stock.
Cost of imported tooling is very high and takes minimum four months to get new
imported tooling. The machine cannot be afforded to stop even for a single day.
Hence there exists a need to find an alternate arrangement to run the machine
without the imported special tooling but with indigenous tools.
Therefore, in the present invention a special tool attachment is made to adapt
the indigenous tools.

OBJECTS OF THE INVENTION
Therefore it is an object of the invention to propose a tool clamping device for
horizontal boring machine which is capable of performing machining operations
without imported special tooling.
Another object of the invention is to propose a tool clamping device for
horizontal boring machine which is capable of adapting wide range of indigenous
tools for the same machine.
Yet another object of the invention is to propose a tool clamping device for
horizontal boring machine which makes the machining operations economical.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig.1 - shows the tool clamping device according to the invention.
Fig.2 - shows details of the tool clamping device according to the invention.
Fig.3 - shows the tool clamping device according to prior art.
Fig.4 - shows the tool clamping device and the sleeve according to the invention.

Fig.5 - shows the tool clamping device with cutting tool according to the
invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE
INVENTION
In the old process, the tool clamping device (O) consists of a tool clamping
attachment (1) having length (L) equal to 110 mm and M-30 thread (A) at one
end and a profile (B) at the other end which goes inside the machine spindle.
The thread end (A) is attached with M-30 thread (C) of a tool holding attachment
(2). A plate (E) having a hole of 14 mm dia accommodates an alien head bolt (F)
having 13 mm dia thread which goes inside an imported tool (D) having 18 mm
hole. A sleeve goes inside the hole of tool (D). The outside taper of the sleeve
matches with the inside taper of the tool holding attachment (2). The sleeve
holds the imported cutting tool. The length of the tool holding attachment (2) is
280 mm.
As shown in fig.l, in the present invention the tool clamping device (N) has been
manufactured with necessary changes in tool clamping attachment (3) and tool
holding attachment (4) so that the device can be accommodated in the same

horizontal boring machine and at the same time can accommodate indigenous
cutting tools.
In the present invention, the length of the tool holding attachment (4) is 230 mm
and bore attachment (5) is 40 mm dia. Length of tool clamping attachment (3) is
245 mm. The length 230 mm of holding attachment (4) and 245 mm of clamping
attachment (3) are so designed that the device (N) can accommodate the sleeve
(8) holding the cutting tool without sacrificing the rigidity of the device (N). The
tool clamping attachment (3) is provided with M-24 thread for a length of 80 mm
at one end and has a profile (B) at the other end that goes inside the machine
spindle to get the drive. A chuck nut (6) having four slots (7) for tool tightening
is provided over M-24 thread of tool clamping attachment (3) for tightening of
tools. The chuck nut (6) is of 36 mm dia and 20 mm width. The clamping
attachment (3) passes through 40 mm dia bore of tool holding attachment (4). A
sleeve (8) having M-24 thread at its rear end gets tightened with M-24 thread of
clamping attachment (3) inside the tool holding attachment. The other side of
sleeve (8) holds the tool for machining. The chuck nut (6) is used to lock the
sleeve (8) with the tool clamping attachment (3).

The inside taper (10) of the tool holding attachment (4) is ISO 50 to suit the
sleeve (8) having outside taper ISO 50 (12) while the outside taper of the said
attachment (4) is ISO 60 (11).
From the prior art, the internal threading M-30, special alien bolt consisting of M-
12 head, M-18 threading and plates with a hole of 14 mm dia for fixing tools are
all eliminated.
In the present invention the tool clamping device includes two stoppers (9) to
control and guide the rotation of cutting tool during operation. The stopper (9) is
locked with M-10 alien screw to avoid its loosening.

WE CLAIM
1. A tool clamping device (N) for horizontal boring machine comprising:
a tool clamping attachment (3) for clamping a sleeve (8);
a chuck nut (6) mounted on the said attachment for locking the sleeve
(8);
a sleeve (8) for holding the cutting tool;
a tool holding attachment (4) for accommodating the sleeve (8);
characterised in that the lengths of tool clamping (3) and tool holding
attachment (4) are adopted to accommodate the sleeve (8) as well as fix
the profiled (B) portion of the said clamping attachment with the machine
spindle to get the drive.
2. A tool clamping device as claimed in claim 1, wherein the tool holding
attachment (4) having a 40 mm dia hole (5) accommodates the tool
clamping attachment (3).
3. A tool clamping device as claimed in claim 1, wherein the length of tool
clamping attachment (3) is 245 mm and that of tool holding attachment
(4) is 230 mm.

4. A tool clamping device as claimed in claim 1, wherein the inside taper of
the tool holding attachment (4) is ISO 50 to suit the sleeve (8) and the
outside taper of the said attachment (4) is ISO 60.
5. A tool clamping device as claimed in claim 1, wherein the outside taper of
the sleeve (8) is ISO 50 (12).
6. A tool clamping device as claimed in claim 1, wherein the tool clamping
attachment is provided with a profile (B) at one end for locking with the
spindle to get the drive.
7. A tool clamping device as claimed in claim 1, wherein the stoppers (9) are
provided for controlling and guiding the rotation of cutting tools when the
stoppers (9) are fixed with M-10 alien screws.

A tool clamping device (N) for horizontal boring machine consists of a tool clamping attachment (3) for clamping a sleeve (8), a chuck nut mounted on the said attachment for locking the sleeve (8) and a tool holding attachment (4) for
accommodating the sleeve (8). The sleeve (8) holds the cutting tool. The lengths of tool clamping (3) and tool holding attachment (4) are adopted to accommodate the sleeve (8) as well as fix the profiled (B) portion of the clamping attachment (3) with the machine spindle to get the drive.