FIELD OF INVENTION
The present invention relates to a fixture for CNC facing lathe for clamping and holding
the job.
BACKGROUND OF THE INVENTION
CNC Facing Lathe as shown in Fig.1 is a special purpose machine used for machining of
Gas Turbine Discs and Steam Turbine components viz. Valve Seats, Inlet Insert, Breech
Nuts, Discs for Steam Turbines.
The CNC facing lathe does not have any provision of tallstock. One of the principal
requirements for achieving accurate machining of components is how the job is set on
the machine. Due to absence of the tallstock on the machine there was nothing to
support and hold the job while setting the jobs.
To set the job and to hold job during setting on the machine, there required a huge
manpower and crane Involvement and also manpower required to hammer and tighten
the job and try to set the job by hit and try method.
The process used to consume a lot of energy In terms of time and manpower. The
ultimate result was In reduction of productivity due to monetary wastage as per hour

cost of the machine is very high and damage to the machined job due to hammering
and finally uncertainty of timely delivery and failure of commitment due to delay in jobs.
The complete operation was very unsafe for operator, as the chance of the injury was
more due to the slant guide ways of the machine. To overcome the above limitations a
new fixture was developed to hold the job firmly without any engagement of overhead
crane and huge manpower.
OBJECTS OF THE INVENTION
It is therefore, an object of the present invention to propose a fixture for CNC facing
lathe which eliminates the limitation of job holding means.
Another object of the present invention is to propose a fixture for CNC facing lathe
which facilitates accurate setting of critical job.
A further object of the present invention is to propose a fixture for CNC facing lathe
which increases the production and reduces the cost of machining.
A still further object of the present invention is to propose a fixture for CNC facing lathe
which reduces the manpower engagement.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig.1 - shows a photographic view of CNC facing lathe without tail stock support
Fig.2 - shows a photographic view of 4 to 5 men required at the time of job loading
and setting on machine
Fig.3 - shows the schematic diagram of the fixture according to new invention
Fig.4 - shows a schematic diagram of Assembly of fixture, Job loading with the help of
fixture set on the machine
Fig.5A & 5B - shows a photographic view of jaws set for loading with connecting nut in
the centre of the chuck. One man set the job with the help of invented fixture
Fig.6 - shows a photographic view of connecting nut fixed with a chuck
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE
INVENTION
As shown in Fig.3, the fixture is provided a central round stud(l) having a plurality of
flanges (3,4) type clamping means from both sides. Both the ends of the central round
stud (1) having external threads. The first end of the central round stud is provided
with a back nut (2) which is being set to the central spindle of the machine and acts as
a coupling between the central spindle of the machine and the fixture device .
First end of the round stud is provided at the back side plate (3) and the second end of
the stud is also provided with a front side plate (4). The external thread of the second
end of the stud is aligned with a connecting nut (5) for mounting a small stud (6) with
the central round stud (1) of the original device in order to extend the length of the
device. The second end of the stud having external thread for fixing and holding the job
by means of a supporting plate (7) and a tightening nut (8) and pressed against
distance pieces clamped on the chuck. The fixture device is made of steel materials.
With the implementation of the new device, there is saving in the job setting time and
the operator feels more safety in working.
WE CLAIM
1. A fixture for facing lathe for clamping and holding during setting the job
comprises:
- a central round stud (1) having external thread at both end;
- first end of the stud is provided with a back plate (3) and a back nut (2) is
fastened on left side of the back plate (3) which is also mountable with
the central spindle of the machine;
- second end of the stud (1) is provided with a front plate (4) and a
connecting nut (5) is fastened on right side of the front plate;
- a second stud (6) having external thread on both end;
- first end of the second stud (6) is mountable with the connecting nut (5);
- second end of the second stud (6) is fastened with a tightening nut (8)
through a support plate (7) from inside the job;
characterized in that the back nut (2) and connecting nut (5) functioning
as a coupling between the central spindle of the machine and the first
stud of the fixture maintaining a straight alignment right angled to the
facing chuck and the second stud hold the job after setting from outside
far end through a connecting nut via a supporting plate and a tightening
nut.

The present invention relates to a fixture for facing lathe for clamping and holding
during setting the job comprises a central round stud (1) having external thread at both
end and first end of the stud is provided with a back plate (3) and a back nut (2) is
fastened on left side of the back plate (3) which is also mountable with the central
spindle of the machine and second end of the stud (1) is provided with a front plate (4)
and a connecting nut (5) is fastened on right side of the front plate and a second stud
(6) having external thread on both end and first end of the second stud (6) is
mountable with the connecting nut (5) and second end of the second stud (6) is
fastened with a tightening nut (8) through a support plate (7) from inside the job
characterized in that the back nut (2) and connecting nut (5) functioning as a coupling
between the central spindle of the machine and the first stud of the fixture maintaining
a straight alignment right angled to the facing chuck and the second stud hold the job
after setting from outside far end through a connecting nut via a supporting plate and a
tightening nut.