The present invention relates to apparatus for milling of casting. Milling
fixture used in CNC shop to hold the casting in manners that all reference
surfaces given on casting are in proper positioned on milling fixture for machining
10 of the casting.
.
BACKGROUND OF THE INVENTION
15 This invention pertains to work holding fixtures for milling machine, and
more particularly to a precision work holding fixture 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 Work holding fixture for
milling machine which is rugged, compact, and capable of high precision
20 holding of casting having supporting features. This milling fixture helps to
accomplished with a minimum of setup time and a maximum of productivity.
.
SUMMARY OF PRESENT INVENTION
25
In accordance with one aspect of present invention is to provide a milling
fixture that facilitates proper positioning of the casting.
In accordance with second aspect of present invention is to provide an
30 accurate positioning of casting on fixture and proper resting of datum surfaces
provided on casting on the resting pads.
In accordance with another aspect of present invention is provided proper
holding of casting.
Annexure‐II
In accordance with yet another aspect of present invention is to provide a
more rigid milling fixture.
.
In 5 accordance with yet another aspect of present of invention is to provide
a milling fixture that provides the resting of the casting at three project pads.
In accordance with yet another aspect of present invention is to provide a
milling fixture having a dialing face on base plate.
In accordance with another aspect of present invention is to provide a
10 lighter milling fixture.
In accordance with yet another aspect of present invention is to provide a
milling fixture that can be properly and effectively utilized to hold and firmly fixed
the work piece by lesser skilled individuals.
15 BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the present invention will become more apparent
and descriptive in the description when considered together with figures/flow
20 charts presented:
Fig. 1 is a Sectional Front view of Milling Fixture
Fig. 2 is a Side view of Milling Fixture
Fig. 3 is a Top view of Milling Fixture
25
DETAILED DESCRIPTION
Referring now to FIG. 1, 2& 3 present invention is a milling fixture 14
30 adopted for used on CNC M/c HR3C.
The milling fixture 14 is designed to hold the casting 13 well positioned as
reference Surfaces given on casting 13 & rigidity for milling operation of casting
13.Milling fixture comprise a base plate 1 having a substantially flat top surface
35 ‘A’ and bottom surface ‘B’, base plate made of mild steel of 30 mm thick, surface
Annexure‐II
‘B’ of base plate rest on M/C bed & clamped base plate 1 through 4-C’ bore holes
15 made in base plate 1 on M/c bed.
Three resting pad 2 of ø16, EN-31, HRD & GRD 50-55 RC fixed 5 on base
plate 1 the casting 13 rest at three points on the top surface of resting pads 2 the
top surface of all the resting pad 2 is Grinded & in one line & also parallel to
surface B of base plate 1 within 0.010 mm as shown on sectional front view,
casting rest on these resting pad 2.
10
Position pin 3 of made of EN-8, HRD & GRD 40-45 RC fixed with base
plate 1 to position the casting 13 to get datum position for milling. L-Block R.H. 4
& L-Block L.H. 5 of Mild Steel is fixed on base plate 1 with the Allen screw 12 &
Dowel pin 11.
15
Position Bung R.H. 6 of EN-8, HRD & GRD 40-45 RC fixed with L-Block
R.H. 4 to position the casting. Position Bung L.H. 7 of EN-8, HRD & GRD 40-45
RC fixed with L-Block R.H. 5 to position the casting. Casting work piece is
clamped in three points with eight clamps of EN8 to securely hold the casting to
20 avoid the vibration on casting during machining.
Dialing face ‘C’ in base plate 1 used as a datum for the manufacturing of
milling fixture 14 to maintain the position of all the items as describe above & this
dialing face ‘c’ is also used to position the milling fixture when fixing on M/C bed.

WE CLIAMS:-
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 milling fixture for holding and supporting casting adapted to be positioned on work table of CNC milling machine. The milling fixture comprising:
- Base Plate adapted to be coupled to the bed of milling machine
- Three resting pad that is rigidly coupled to the top surface of the base plate. casting rests on top surface of these pads.
- Position pin that guide the casting to remain in pre determined position.
- RH and LH, L block fixed on the top surface of the base plate and aving arrangements for holding the position bungs.
-clamp to securely hold the work piece on milling fixture
2. The milling fixture of claim 1 wherein, bottom surface of the base plate is adapted to positioned on the machine bed.
3. The milling fixture according to claim 1 further including four counter bore hole for fixing the milling fixture on machine bed.
4. The milling fixture of claim 1 further comprising a dialling face that provides reference edge for the other sub component of milling fixture. ,TagSPECI:As per Annexure-II