FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
A deburring cutter assembly
APPLICANTS
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS KULKARNI ARUN B and SARODE RAJESH K
Both Indian Nationals
of TATA MOTORS LIMITED,
an Indian company having its registered office
at Bombay House, 24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
PREAMBLE TO THE DESCRIPTION The following specification particularly describes the invention and the manner
in which it is to be performed.

FIELD OF INVENTION
The present invention relates to a cutter assembly and more particularly to a deburring cutter assembly with an arrangement for varying a thickness of deburring cutter assembly.
BACKGROUND OF INVENTION
A bush in a typical deburring cutter assembly includes an internal diameter, external or outer diameter and thickness. During deburring process, the inner surface of the cutter reduces due to abrasive contact with the material to be finished. In this case, the pressure applied by cutter on the material to be finished is reduced. In conventional systems, the pressure on cutter is maintained by varying the thickness of the bush. It is possible to change the thickness of the bush by removing the material form either side or by addition of required thick spacers or shims or by making new bush of required thickness. The pressure on cutter can be increased or decreased by addition or removing spacers and or shims in a suitable combination. In conventional arrangement the end roller has to be removed every time to put the combination of spacers and shims. Also there is limitation to change dimension 'D' because of defined thickness of spacers and shims.
OBJECT OF THE INVENTION
The primary objective of the present invention is to provide a system and method for varying the thickness of bush in a deburring cutter assembly.
Another objective of the present invention is to provide a system and method for varying the thickness of bush by lock nut arrangement without dismantling the cutter
assembly.

SUMMARY OF THE INVENTION
The embodiments herein provide a system and method for varying thickness 'T' of bush in a cutter assembly. A deburring cutter assembly comprising a pair of cutters with a bush/spacer provided between said cutters, a housing plates provided at outer ends of both cutters with a compression springs housed on inner pitch circle diameter of said housing plate to apply pressure on said cutters, a continuous bush/spacers provided on the outer ends of both housing plates extending till end rollers, wherein said cutter assembly according to present invention having a bush/spacer with external threads, a first lock nut and second lock-nut with internal threads is fastened on said bush/spacer to apply pressure on said cutter by varying thickness of said bush by said first and second lock-nut. The bush/spacer with lock nut arrangement is replaced with an earlier continuous bush/spacer to vary the thickness'T' of said bush by said locknut arrangement. The continuous bush/spacer can also be cut in-between to introduce the bush with lock nut arrangement according to present invention.
The system comprises a bush with external threads, a first lock nut and second lock-nut with internal threads is fastened on said bush. The pressure on said cutter is adjusted by increasing or decreasing the thickness 'T' of said bush by said first and second lock-nut. The pair of lock-nuts provided on bush is free to rotate in clockwise or anti-clock wise direction. The first and second lock-nut includes a ribs and groves in alternate sequence on its outer circumference for easily adjusting the lock-nut in desired direction. The bush/spacer with a lock nut arrangement is provided between said cutters for varying the width between said cutters. The bush/spacer with a lock nut arrangement can also be provided on either the outer ends of said housing plate or any one outer end of said housing plate for applying pressure on said cutter assembly.
According to embodiment of the present invention, the method for varying thickness of bush in a cutter assembly, comprising steps of unlocking second locknut fastened

on a bush, creating a gap between first lock-nut and second lock-nut so as to rotate first lock-nut freely in clockwise or anticlockwise to arrive at the desired thickness and fastening second locknut against first locknut after obtaining desired thickness of said bush.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows sectional view of deburing cutter assembly with a bush and a pair of
lock-nut, according to present invention.
FIG. 2 shows a perspective view of the bush and lock-nut of FIG. 1.
FIG. 3 shows a perspective view of a pair of locknuts assembled on threaded bush,
according to present invention.
FIG. 4 shows a sectional view pair of locknuts assembled on threaded bush,
according to present invention.
FIG. 5 shows a sectional view of the threaded bush extension.
FIG. 6 shows a sectional view of the Lock nut.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only and not for the purpose of limiting the same.
The sectional view of a deburring cutter assembly is as shown in FIG. 1. As shown in FIG. 1, a pair of deburring cutters 3 is provided to remove the burr produced after hobbing or shaping of gears. There is provided an entry chamfer 12 for these cutters to hold the gear width under pressure. The freely held gear rotates as it is driven by the cutter rotation to remove the burr. The pressure on these cutters 3 is maintained by providing a number of compression springs 13 housed in plates 14 on suitable pitch circle diameter (PCD) on both sides of these cutters. A bush or spacer 15 is provided in between said cutters and on the outer sides of both cutters. After

regrinding / resharpenings, the gap in between these cutters changes. The pressure required for deburring also needs to be re-adjusted after regrinding / resharpening of the cutters 3. The pressure on cutter is maintained by varying the thickness (T) of the bush. In conventional deburring assembly, the bush/shim is continuous on either side of housing plate 14 and extends till the end rollers. It is possible to change the thickness 'T' of the bush 2 by removing the material form either side or by addition of required thick spacers or shims or by making new bush of required thickness. The pressure 'P' on cutter 3 can be increased or decreased by addition or removing spacers 4 and or shims 5 in a suitable combination. The end roller 6 has to be removed every time to put the combination of thin spacers and shims. Also there is limitation to change dimension 'D' because of defined thickness of spacers and shims. A deburring Cutter Assembly according to present invention is provided to adjust the required pressure on the cutters 3 without dismantling the assembly.
The system and method according to present invention is provided for varying thickness 'T' of bush/spacer 2 in deburring of cutter assembly 1 is as shown in FIG. 1 to FIG. 6. The system comprises a bush 7 with external threads, a first lock nut 8 and second lock-nut 9 with internal threads is threadbly mounted on said bush 7 for adjusting the position thereby increasing or decreasing the width "T" of the bush and lock nut arrangement. The bush/spacer 2 can be completely removed to replace the bush 7 with locknut arrangement (8, 9) according to present invention. The bush 2 can be cut in between to replace a bush with locknut arrangement as shown in FIG. 1. The pressure 'P' on said cutter 3 is adjusted by increasing or decreasing the thickness 'T' of bush 7 and lock-nut (8, 9) arrangement. The pair of lock-nuts provided on bush 7 is free to rotate in clockwise or anti-clock wise direction to arrive at the desired thickness. The first lock-nut 8 and second lock-nut 9 includes a ribs 10 and groves 11 (Refer FIG. 6) in alternate sequence on its outer circumference for easily adjusting the lock-nut in desired direction. The thickness of bush 7 and lock nut assembly in the cutter assembly can be varied by unlocking second locknut 9

fastened on bush 7, creating a gap between first lock-nut 8 and second lock-nut 9 so as to rotate first lock-nut 8 freely in clockwise or anticlockwise (in direction Dl and D2) to arrive at the desired thickness 'T''and fastening second locknut 9 against first locknut 8 after obtaining desired thickness'T'.
According to present invention, the bush 7 with locknut arrangement can be provided in between said cutters 3 to increase or decrease the distance between said cutters 3. Also the bush with locknut arrangement can be provided on both the outer sides of cutter assembly or at any one side to apply the pressure on the cutter assembly.
ADVANTAGE:
• The system and method according to present invention is provided to vary the thickness of bush in deburring cutter assembly.
• The thickness of bush is varied by adjusting the newly designed bush by lock nut arrangement without dismantling the cutter assembly.
• The bush with a pair of lock-nut provided to apply constant pressure on the cutter in a deburring assembly.
The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.

We Claim:
1. A deburring cutter assembly, comprising;
a pair of cutters (3) with a bush/spacer (15) provided between said cutters; housing plates (14) provided at outer ends of said cutters (3) with a compression springs (13) housed on inner pitch circle diameter of said housing plate (14) to apply pressure on said cutters (3); bushes/spacers (2.7) provided on the outer ends of both housing plates (14) extending till end rollers (6); wherein said cutter assembly (1) having atleast one bush/spacer (7) with external threads, two position adjustable lock-nuts (8,9) with internal threads threadably mounted on said bush/spacer (7) to apply pressure on said cutter (3) by varying thickness 'T' of said bush and lock nut arrangement.
2. The assembly according to claim 1, wherein said pair of lock-nuts provided on bush (7) is free to rotate in clockwise or anticlock wise direction.
3. The assembly according to any one of the preceding claims, wherein one lock-nut (8) configured to adjust the Thickness "T" and the second lock-nut (9) lock against the first to secure the assembly.
4. The assembly according to any one of the preceding claims, wherein said first lock-nut (8) and second lock-nut (9) having a ribs (10) and groves (11) in alternate sequence on its outer circumference for easily adjusting the lock-nut in desired direction.
5. The assembly according to claim 1, wherein said bush/spacer with a lock nut arrangement is provided between said cutters (3) for varying the width between said cutters.

6. The assembly according to claim 1, wherein said bush/spacer with a lock nut arrangement is provided outer ends of said housing plate (14) or any one outer end of said housing plate (14) for applying pressure on said cutter assembly.