FIELD OF INVENTION
The present invention relates to a tip copying fixture with hydraulic clamping to
carryout tip copying operation of gas turbine blades on vertical milling machine.
BACKGROUND OF THE INVENTION
In new blade shop roots of the gas turbine blades are machined on HMC
machine from the forged profile finished blades having stock on root only. While root
machining finished, thin profile of the blade is clamped in a special fixture called
control segment. In the same setting Tip Copying operation can’t be done on HMC
machine. Therefore we need to take away the blades from the control segment and do
the further operation on VMC machine. But for holding the blades, arises the
requirement of the new fixture which can clamp both root and profile of the blades as
shown in Fig.11.
In view of above a hydraulic clamping fixture which can accurately hold the root
and profile portion rigidly has been design and manufactured in vertical milling
machine itself, which can properly clamp the blade to carry out the tip copying
operation of Gas Turbine Blades.

OBJECTS OF THE INVENTION
Therefore, it is an object of the invention to propose a tip copying fixture with
hydraulic clamping to carryout tip copying operation of gas turbine blades on vertical
milling machine, which is capable of holding the blades rigidly and accurately by
clamping both root and profile of the blades with hydraulic pressure.
Another object of the invention is to propose a tip copying fixture with hydraulic
clamping to carryout tip copying operation of gas turbine blades on vertical milling
machine, which helps to machine root and profile of the blades smoothly and
accurately.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure A shows the Isometric View of Fixture.
Figure 1 shows the Base Plate of Fixture.
Figure 2 shows the Root Pad Resting Block.
Figure 3 shows the Root Pad.
Figure 4 shows the Hydraulic Cylinder.
Figure 5 shows the Top Clamping
Figure 6 shows the Profile Clamping Arm.
Figure 7 shows the Gripping Jaw.

Figure 8 shows the Profile Pad.
Figure 9 shows the Profile Resting Block.
Figure 10 shows the Hydraulic Cylinder
Figure 11 shows the Complete assembly of Fixture in Blade Clamping Position.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE
INVENTION
The complete hydraulic fixture (Fig. A) consists of a base (1) measured 700mm
X 350mm X 50mm having a slot through which mounted sliding unit Root pad resting
Block (2) and profile resting block (9) slide along the length of the fixture base and can
be set according to the blade length. In root pad resting block (2) holes (H) are made
as per shown in drawing to fix the root pad (3) at its top. This root pad (3) fix the Root
of the gas turbine slot and top portion of the root of the blade (B) is clamped by the
top clamping pad (5) which is actuated by the hydraulic cylinder (4). This hydraulic
cylinder (4) is mounted on root pad resting block (2). Other end i.e. Profile of the
blade rests at Profile pad (8) which is mounted over profile resting block (9). Top of
the profile of the blade is clamped by gripping jaw (7) and this gripping jaw (7) is
mounted on profile clamping arm (6). This Profile clamping arm (6) is actuated by the
hydraulic cylinder (10) which is mounted on profile resting block (9). On actuation of

hydraulic clamping arm top clamping pad (5) and gripping jaw (7) push the blade (B)
downward at the root end and profile end respectively and restrict the upward motion
of the blade. Now the blade (B) is clamped on new hydraulic clamp fixture to carry out
the tip copying operation on gas turbine blades.

WE CLAIM
1. A tip copying fixture with hydraulic clamping to carryout tip copying operation of
gas turbine blades on vertical Milling machine, the said fixture consists of;
a base (1);
a root pad resting block (2) and a profile resting block (9) mounted on the base
(1), the said base having slots along its length to facilitate sliding and setting at
required place of the said blocks (2,9);
a root pad (3) fixed at the top of root pad resting block through holes (H);
a hydraulic cylinder (4) disposed on root pad resting block (2);
a clamping pad (5) mounted over the cylinder (4);
a profile pad (8) mounted over profile resting block (9) for facilitating resting of
profile of a blade (B);
a profile clamping arm (6) fixed on a hydraulic cylinder (10) mounted on the
profile resting block (9);
a gripping jaw (7) disposed on said profile clamping arm (6);
characterized in that, the root pad (3) fixes the root of the gas turbine slot
and top portion of the root of the blade (B) is clamped by the top clamping pad (5)
being actuated by the hydraulic cylinder (4), wherein the hydraulic cylinder (10)
actuates the profile clamping arm (6) for actuating the gripping jaw (7) to clamp the

top of profile of blade (B) when the hydraulic cylinders actuates top clamping pad (5)
at the root end and gripping jaw (7) at profile end, for pushing the blade (B)
downwards restricting the upward motion of the blade (B) making the blade (B) ready
for carrying out the tip copying operation of gas turbine blades.
2. The tip copying fixture as claimed in claim 1, wherein the base plate has the
dimension of 700mm X 350mm X 50mm.