FIELD 5 OF THE INVENTION:
The present invention is for holding small, precision, cage/ shell type cylindrical parts
where various type of machining such as milling, drilling, Jig grinding etc is needed
to done on the periphery of the part. For precision machining operation, achieving
close geometrical parameters, close dimensional tolerances and angular position on
10 the general type of fixture is very difficult. This device is mounted on the CNC rotary
table to get correct angular position on CNC Milling machine. This device is also
useful to get the precise symmetry of holes or machined features from face.
BACKGROUND OF THE INVENTION
15 A lot of cylindrical components are used for various purposes in industries. Also,
many tubular parts are used when various machining such as milling, drilling etc is
required to be done the periphery. Some of the materials are very brittle and highly
porous with very close dimensional and geometrical tolerances. Initially general type
rotary table were used for small components which consumes lot of time and energy.
20 So, special type of holding device is required.
SUMMARY OF PRESENT INVENTION
In accordance with one aspect of Present invention is to provide proper butting of
components on butting face of the holding device. Proper butting is ensured by
25 providing a circular groove at the mating surface of face and center pin.
In accordance with second aspect of Present invention, a spacer is put on the pin to
avoid collision of cutting tool with center pin during cutting operation.
In accordance with third aspect of present invention a non metallic cylindrical sleeve
is inserted against the delicate component to avoid damage of part face.
30 In accordance with another aspect of Present invention a knurled nut is used on
threaded portion of pin to clamp the sleeve & component against the perpendicular
butting face.
Annexure‐II
In accordance with another aspect of Present invention a center bung is provided at
the base of the holding device for true centering on the CNC Rotary Table.
BRIEF DESCRIPTION OF THE DRAWINGS
5
With the help of drawings /sketches the present invention may be well understood
very clearly.
Figure/sketch 1: is the complete Assembled Holding Device comprises of following
10 detailed parts:
1. Base Plate
2. Support Plate
3. Locating Bung
4. Allen Head Screw
15 5. Sleeve
6. Spacer
7. Small Special Nut
8. Knurled Special Nut
20 Detail Description
Present invention Holding Device is used on CNC Rotary Table for holding cylindrical
jobs to carry out milling and drilling operation on periphery.
Item no. 3 locating Bung is fitted at the bottom of the item no. 1 Base plate. This
locating bung of holding device is inserted into the center locating hole of the rotary
25 table. Outer diameter of locating bung is made with very close dimensional tolerance
to suit with central hole of the rotary table. Run out of locating bung is ensured within
0.005mm with respect to rotary central hole and face.
Item no. 1 Base plate is clamped on the rotary table using two numbers item no 4
(Allen Head Screw).
30 Butting face of the item no. 2 support plate and pin axis is made true with the help of
Dial Test Indicator (DTI). Item no 6 Spacer is a consumable part made of nylon/
Annexure‐II
Teflon & made as per the requirement of the job. This spacer is put on the center pin.
Spacer is required to avoid direct collision of cutting tool with center pin while making
through hole in the delicate cylindrical part. Spacer is lightly clamped with item no. 7
small special nut to restrict the axial movement.
Component 5 is put on the spacer and then item no 5 sleeve is put against the
component to restrict the axial movement of component. Item no 8 Knurled Special
nut is used to clamp the sleeve thus avoiding the direct contact of face of component
with metallic nut face.
At the beginning machining operation is carried out at any angle of rotation of rotary
10 table. This angular value is made zero. For doing the machining operation on the
periphery of the component at the desired angle Indexing of holding device is carried
out by input of through commands of CNC Rotary Table. This process is repeated till
the machining operation is completed at all desired indexed position on the
component.

WE CLAIMS:-
Accordingly, the description of the present invention is to be considered as illustrative only and it 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. Holding device for cylindrical parts for milling/ drilling on periphery is a tool which is used for holding and locating small cylindrical shaped precision & delicate component where machining is required on periphery.
2. The holding device of claim 1 comprises one central locating bung for true centering on the CNC Rotary Table.
3. The holding device of claim 1 wherein base plate having C’bore holes is used for mounting the holding device on the face of the rotary table with Allen Head Screw.
4. The holding device of claim 1 wherein support plate comprises of center pin with threaded feature at the open end to hold spacer, small special nut, Sleeve and the component.
5. The holding device of claim 1 wherein knurled nut is used on threaded portion of pin to clamp the sleeve & component against the perpendicular butting face. ,TagSPECI:As per Annexure-II