FIELD OF THE INVENTION
5
This invention relates to fixtures for precision turning operations on internal
diameter of a heavy Hollow casting on Lathe machine. More specifically, it relates to a
fixture, which may be used to precisely hold and maintain the concentricity of the
10 Hollow casting at variable length for internal turning operation on Lathe machine.
Fixture used to hold the Hollow casting at multiple lengths to remove the chances of any
deviation of workpiece with respect to the dialing surface due to casting weight.
BACKGROUND OF THE INVENTION
15
This invention pertains to fixtures for holding the Hollow casting on Lathe
machine, and more particularly to a holding fixture adapted to support heavy workpeice
to be machined on internal diameter and maintain the concentricity of the internal
surface accurately relative to the dialing surface. An object of this invention is the
20 provision of a new and improved Hollow casting holding fixture for internal diameter
turning operations on Lathe which is rigid, rugged, compact, and capable of high
precision holding of Hollow casting. This fixture helps to minimize the setup time and
maximize the productivity.
25 SUMMARY OF PRESENT INVENTION
In accordance with one aspect of present invention is to provide a fixture that
facilitates holding of a hollow casting at variable lengths and maintain precise
30 concentricity, for internal diameter turning operations on a Lathe machine
In accordance with second aspect of present invention is to provide a fixture that
supports the hanging hollow casting at different lengths thereof while the Hollow
casting is being turned at internal diameter in predetermined shape and size.
Annexure‐II
In accordance with second aspect of present invention is to provide a fixture for
holding the Hollow casting for accurate positioning of Hollow casting on fixture with
respect to dialing surface.
In accordance with another aspect of present invention is provided a fixture 5 for
rigid clamping of Hollow casting on Lathe machine.
In accordance with yet another aspect of present invention is to provide a fixture
for holding Hollow casting adapted to be fixed on the chuck of the Lathe machine for
internal diameter turning operations.
10 In accordance with yet another aspect of present invention is to provide a more
rigid fixture to hold the Hollow casting.
. In accordance with yet another aspect of present invention is to provide a
fixture for holding Hollow casting at variable lengths to support the weight of the
hanging hollow casting.
15 In accordance with another aspect of present invention is to provide a lighter
fixture for holding the Hollow casting during turning operations.
In accordance with yet another aspect of present invention is to provide a fixture
that can be properly and effectively utilized to hold and firmly fixed the Hollow casting
by lesser skilled individuals.
20 In accordance with yet another aspect of present invention is to provide a fixture
for holding a Hollow casting that have studs provided at multiple lengths to eliminate
the distortion during machining due to weight of the casting.
BRIEF DESCRIPTION OF THE DRAWINGS
25
The features and advantages of the present invention will become more apparent and
descriptive in the description when considered together with figures/flow charts
presented:
30 Fig. 1 is a Sectional Front view of fixture for holding Hollow casting in multiple planes
Fig. 2 is a Top view of fixture for holding Hollow casting in multiple planes
Annexure‐II
DETAILED DESCRIPTION
Referring to fig. 1 & 2 present inventions is a fixture 16 used to hold and 5 position
the workpiece 17 on the Lathe machine spindle and adapted for use for locating the
workpiece 17 for internal turning operation on Lathe machine. The fixture 16 is designed
to hold the workpiece 17 within dimensional tolerance with respect to Dialing surface
and maintain the concentricity.
10 Fixture 16 for holding a workpiece 17 comprises a Fixture plate 1 having a bung
14 which is placed on the spindle of the Lathe. Bung 14 is having four Allen head screw 6
for fixing of the fixture 16 to Lathe spindle. Fixture 16 also consists of Locator plate 7
mounted on the Fixture plate 1 with the help of Allen head screw 6. The internal
diametric surface of the workpiece 17 rest on the outer surface of the Locator 7 and the
15 internal diameter of the workpiece 17 is set exactly concentric to the dialing surface A of
the fixture plate 1.
Fixture plate 1 is adjusted of around the Dialing surface A with reference to the
tool. Surface B is exactly perpendicular to dialing surface A. Work piece 17 rests on
surface B of the Fixture plate 1. Fixture plate 1 also consists of six clamps 2 with
20 different lengths to hold the hollow casting ob surface B. The clamp 2 is provided with
oblong slot 19 for providing adjustment during the mounting of the workpiece 17.
Two Special Studs 8 have been mounted on surface B of the Fixture plate 1
through threaded joints for supporting the hollow casting 17 at extended lengths to
restrict sagging due the weight of the hollow casting. The two clamps 2 with the special
25 studs 8 are provided with heel bolt 12 specially built to provide clamping force on the
far end surface of the work piece 17. One special stud 9 is provide at different lengths
from other five clamps 2 to hold the workpiece 17 at intermediate position to avoid the
sagging of the workpiece 17 due to weight. The clamp 2 with the special studs 9 is also
provided with heel bolt 10 specially built to provide clamping force on the far end
30 surface of the workpiece 17.

WE CLAIMS:-
Accordingly, the description of the present invention is to be considered as illustrative only and is for the purpose of teaching those skilled in the art of the best mode of carrying out the invention. The details may be varied substantially without departing from the spirit of the invention, and exclusive use of all modifications which are within the scope of the appended claims is reserved. We Claim:

1. A fixture for holding and supporting the Hollow casting in horizontal position at various lengths and adapted to be positioned on spindle of Lathe machine. The fixture comprising:
- Fixture Plate adapted to be coupled to the spindle of the Lathe machine and provides supporting surface to other sub component of fixture. Hollow casting fixed and positioned on the top surface of fixture plate.
- A locator block is rigidly coupled to the top surface of the fixture plate with Allen head screw on which the Hollow casting will be located.
- A bung with four Allen head screw attached to the fixture plate on the surface which is mounted on the spindle of the lathe machine.
- Support structure to support the hanging portion of the Hollow casting at different lengths and adjustment nut provided to adjust the height of the support for supporting the Hollow casting during the internal diameter turning operation.
- Clamps provided with provision for clamping the hollow casting at different lengths to hold the Hollow casting and maintain the eccentricity of the internal diameter with reference to the turning tool.
- Special Stud and Special Heal bolts to enable the proper clamping of far end surface of the work piece.
2. The fixture for holding Hollow casting of claim 1 wherein, the fixture plate is provided with a Bung provide with four Allen head screw for mounting the face plate on the machine spindle.
3. The fixture for holding Hollow casting of claim 1 wherein, Fixture plate is having four counter bore holes fixing the fixture with bung and mounting of the fixture on the Spindle of lathe machine.
5. The fixture for holding Hollow casting of claim 1 further comprising a locator block mounted on the top surface of the fixture plate with the help easy alignment of the workpiece on the fixture plate by supporting the internal diameter of the workpiece.
6. The fixture for holding Hollow casting of claim 1 comprising five clamping pad for precisely holding the Hollow casting during the internal diameter turning operations and remove the chances of the damages due to vibrations.
7. The fixture for holding Hollow casting of claim 1 comprising five clamping pad of different lengths of studs for supporting the hollow workpiece in horizontal position and remove the chances of the sagging of the workpiece due to weight.
8. The fixture for holding Hollow casting of claim 1 comprises of special stud and special Heal bolts to enable the proper clamping of far end surface of the work piece. ,TagSPECI:As per Annexure-II