Annexure‐I
Page 1 of 3
HOLDING FIXTURE FOR INTRICATE SHAPE HOLLOW CASTING
5 FIELD OF THE INVENTION
This invention relates to holding fixtures of intricate shaped work piece for
milling machines. More specifically, it relates to a fixture, which may be used to
10 hold and locate hollow casting of various shape and size. Holding fixture used in
CNC machine bed to hold the casting in manners that all reference surfaces
given on casting are in proper positioned on holding fixture for machining of the
intricate casting.
15 .
BACKGROUND OF THE INVENTION
This invention pertains to holding fixtures for holding the intricate shaped
hollow casting on milling machine, and more particularly to a holding fixture
20 adapted to support work to be machined and locate it relative to the cutting
tool. An object of this invention is the provision of a new and improved hollow
intricate shaped casting holding fixture for machine centre which is rigid, rugged,
compact, and capable of high precision holding of intricate shaped hollow
casting. This fixture helps to minimize the setup time and maximize the
25 productivity.
SUMMARY OF PRESENT INVENTION
30
In accordance with one aspect of present invention is to provide a holding
fixture that facilitates holding of a intricate shaped hollow casting in a machining
centre and supporting the walls of the casting thereof while the casting is being
machined to a predetermined shape and size.
Annexure‐I
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In accordance with second aspect of present invention is to provide a
holding fixture for the holding of intricate shaped hollow casting for accurate
positioning of hollow casting on fixture with respect to dialing face of fixture.
In 5 accordance with another aspect of present invention is provided a
holding fixture for the holding of intricate shaped hollow casting for rigid clamping
of hollow casting.
In accordance with yet another aspect of present invention is to provide a
holding fixture for the holding of intricate shaped hollow casting adapted to be
10 fixed on the bed of milling machine.
In accordance with yet another aspect of present invention is to provide a
more rigid holding fixture for the holding of intricate shaped hollow casting.
. In accordance with yet another aspect of present invention is to provide a
holding fixture for the holding of intricate shaped hollow casting having a dialing
15 face on base plate.
In accordance with another aspect of present invention is to provide a
lighter fixture to hold the intricate shaped hollow casting.
In accordance with yet another aspect of present invention is to provide a
holding fixture for the holding of intricate shaped hollow casting that can be
20 properly and effectively utilized to hold and firmly fixed the hollow casting by
lesser skilled individuals.
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: (Refer Annexure-Ia)
30 Fig. 1 is a Sectional Front view of holding fixture
Fig. 2 is a Top view of holding fixture
Fig. 3 is a Side view of holding fixture
Fig. 4 is a Section view at Y-Y of holding fixture
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DETAILED DESCRIPTION
Referring to fig. 1, 2, 3 & 4 present invention is a fixture 10 used to hold
and position the intricate shaped hollow casting 5 ing and adapted for use on multi axis
CNC machining centre. The holding fixture 10 is designed to hold the intricate
shaped hollow casting 11 within dimensional tolerance with respect to dialling
face 12 of fixture 10.
Fixture 10 for holding a intricate shaped hollow casting 11 comprises a
10 base plate 1 having a substantially flat top surface 13 and bottom surface 14.
Base plate is made of mild steel of 40 mm thickness. Surface 14 of base plate,
rest on milling machine bed. Fixture 10 is fixed on the machine centre bed with
the help of four through counter bore holes 15.
Intricate shaped hollow casting 11 rests on surface 13 of base plate 1
15 located in desired place by a guide pin 4 & a position pin 5. Guide pin 4 & a
position pin 5 are fixed on surface 13 of base plate 1 to position the casting with
reference to the dialing face 12 for machining operation. Surfaces 13 & surface
14 of the base plate 1 are made parallel within 0.020 mm by grinding the both
surfaces. Intricate shaped hollow casting 11 clamped on base plate 1 by clamp
20 plate 3. Allen head screw 8 and washer 9 is used as clamping screw to provide
clamping force to clamp plate 3.
Dialing face 12 in base plate 1 used as a datum for the manufacturing of
fixture 10 to maintain the position of all the items as describe above with in the
geometrical tolerance .This dialing face 12 is used to position the fixture on
25 machine centre bed parallel to any one axis of the machine centre.
L-shape angle block 2 of made of EN-8, HRD & GRD 40-45 RC fixed with
base plate 1 to position the intricate shaped hollow casting 11 to get datum
position for milling. L-shape angle block 2 is fixed on base plate 1 with the Allen
screw & Dowel pin 6.
30
Clamp plate 3 made of EN-8 HRD & GRD 40-45 RC is used to securely
clamp intricate shaped hollow casting 11 on base plate 1.Clamp plate 3 is made
taper on bottom portion to enable the surface contact between clamp plate 3 and
intricate shaped hollow casting 11.
35
Guide pin 4 & Position pin 5 of made of standard dowel pin fixed with base
plate 1 to position the intricate shaped hollow casting 11 to get datum position for
machining.

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 intricate shaped hollow casting and supporting the wall of casting adapted to be positioned on work table of machining centre. The fixture comprising:
- Base Plate adapted to be coupled to the bed of milling machine and provides supporting surface to other sub component of fixture. Hollow casting rest and positioned on the top surface of base plate.
- Angle block that is rigidly coupled to the top surface of the base plate with Allen head screw and dowel pins.
- Guide Pin and Position pin that guide the casting to remain in pre determined position with respect to dialing surface and prevent the X, Y direction movement of hollow casting.
- Clamp plate to securely hold the Hollow casting on fixture
2. The holding fixture for the intricate shaped hollow casting of claim 1 wherein, top and bottom surfaces of the base plate are substantially parallel.
3. The holding fixture for the intricate shaped hollow casting of claim 1 wherein, bottom surface of the base plate is adapted to positioned and clamped on the milling machine bed.
4. The holding fixture for the intricate shaped hollow casting of claim 1 wherein, base plate is having four counters bore holes on base plate for fixing the fixture on machine bed.
5. The holding fixture for the intricate shaped hollow casting of claim 1 further comprising a dialling face that provides reference edge for the other sub component of fixture.
6. The holding fixture for the intricate shaped hollow casting of claim 1 further comprising a clamp plate tapered at the bottom to enable the surface contact between casting and clamp plate.
7. The holding fixture for the intricate shaped hollow casting of claim 1 further comprising a guide pin and position pin to quickly position the casting on fixture and restrict X, Y movement of casting during machining.