Claims:We claim:
1) A vibration dampener (214) for a boring operation (200) comprising an annular ring 214(a) inserted into an extending boring bar (204) held in a machine spindle (202) and projecting out through an outer ring (205), adapted to insert into a load ring (206) along with said extending boring bar (204) to arrest vibrations of a tool (212) extending out from a tool holder (210) provided in said extending boring bar (204).

2) The vibration dampener (214) as claimed in claim 1, wherein said annular ring 214(a) is of L-shaped cross-section.

3) The vibration dampener (214) as claimed in claim 1, wherein a clearance fit is achieved between said annular ring (214(a)) and said extending boring bar (204).

4) The vibration dampener (214) as claimed in claim 1, wherein a push fit is achieved between said vibration dampener (200) and said load ring (206).

5) The vibration dampener (214) as claimed in claim 2, wherein a circumferential edge (CE) of said annular ring (214(a)) adapts to the surface of said load ring (206) in its assembled condition.

6) The vibration dampener (214) as claimed in claim 1, wherein the inner diameter of said annular ring (214(a)) is slightly more than the diameter of said extending boring bar (204).

7) The vibration dampener (214) as claimed in claim 1, wherein the outer diameter of said annular ring (214(a)) is slightly less than the inner diameter of said load ring (206).

8) The vibration dampener (214) as claimed in claim 1, wherein said vibration dampener (214) is made up of brass.
, Description:A VIBRATION DAMPENER FOR A BORING OPERATION

FIELD OF THE INVENTION:
The present invention relates to the field of vibration dampeners. Particularly, the present invention relates to a vibration dampener which finds its application in boring operations.

BACKGROUND OF THE INVENTION:
Boring is a machining operation involved in increasing the inner diameter of hollow cylindrical shafts to achieve precision in hole diameters. Workpieces such as Boilers, Pressure Vessels, Impellers etc., have heavy weight and longer lengths. To perform boring operation across longer length of a workpiece, an extending boring bar is required.

Figure 1 illustrates a schematic arrangement of a conventional boring operation.

According to the prior art, a conventional boring operation 100 comprises a machine spindle 102, an extending boring bar 104, an outer ring 105, a load ring 106, a setting ring 108, a tool holder 110 and a tool 112.

The configuration and the mechanism of the conventional boring operation 100 is as follows:
The extending boring bar 104 is inserted into the machine spindle 102 and the extending boring bar 104 is adapted to pass through the outer ring 105 and the load ring 106. The tool holder 110 is inserted into the extending boring bar 104 which in turn accommodates a tool 112 in position. A workpiece is setup in the setting ring 108 coaxial to the tool 112.

Typically, there can be a plurality of load rings 106 depending on the length of the extending boring bar 104 to facilitate in achieving concentricity of the tool with the workpiece.
The problems faced with the conventional boring operation are provided herein below:
1) Vibrations of the tool 112 due to overhang.
2) Production of chatter marks on the workpiece and spoiling its surface finish.
3) Heavy Noise during Boring Operation.
4) Breakage or wear off of the tool 112 frequently.
5) Non achievement of precise boring and risk of boring operation going out of prescribed tolerance limits.

Some techniques have been disclosed in the prior art to minimize the vibration of the tool during machining operation.

US Patent Application Publication no. 20140105701A1 published on April 17th, 2014 titled “Anti Vibration Member and Cutting tool” discloses an anti-vibration member comprising a member main body having rubber elasticity or viscoelasticity, wherein the anti-vibration member is capable of being mounted on an outer surface of a tool main body by a frictional force against the outer surface. The published patent application teaches about reinforcing a tool by insertion of a rubber ring around its outer surface but the published patent application is silent on arresting vibrations due to overhang of the tool especially in boring operations. Further, the invention in the cited prior art has its own limitations like adding weight on the tool directly changes the dynamic behavior of the tool and replacement of the tool is difficult due to rubber dampener.

US Patent Application Publication no. 20150375305A1 published on December 31st, 2015 titled “Optimized Vibration Absorber” discloses a tuned or tunable boring tool including a boring bar defining an elongated cavity therein. A distal end of the boring bar is configured to support a tool or cutting insert. The boring tool further includes a dynamic vibration absorber inserted within the elongated cavity of the boring bar. The dynamic vibration absorber includes a mass that vibrates in conjunction with vibration of the boring bar. The mass has a proximal end and a distal end. The dynamic vibration absorber further includes at least one resilient proximal support positioned adjacent to and supporting the proximal end of the mass and at least one distal resilient support positioned adjacent to and supporting the distal end of the mass. The at least one proximal support and at least one distal support have a different stiffness. The granted patent teaches about a dynamic vibration absorber provided in a boring bar cavity to counter balance the vibrations from the tool but the granted patent is silent on arresting vibrations due to overhang of the tool. Further, the method of providing a vibration absorber in the cavity of the boring bar, disclosed in the cited prior art is very complicated.

Therefore, there is felt a need for development of a vibration dampener for a boring operation to overcome the drawbacks of the prior art and thereby achieve longevity of the tool, precision in operation and good surface finish on the workpiece.

OBJECTS OF THE INVENTION:
An object of the present invention is to provide a vibration dampener for boring operations to achieve better surface finish of the workpiece.

Another object of the present invention is to provide a vibration dampener for boring operations to achieve long life of a tool.

One more object of the present invention is to provide a vibration dampener for achieving precision in boring operations.

Still another object of the present invention is to provide a vibration dampener for increasing cutting speed and feed in boring operations.

Further another object of the present invention is to provide a vibration dampener which helps in finishing the boring operation at less time.

Yet another object of the present invention is to provide a vibration dampener to reduce noise in boring operations.

SUMMARY OF THE INVENTION:
In accordance with the present invention a vibration dampener for a boring operation is provided, the vibration dampener comprising an annular ring encompassing an extending boring bar and adapted to insert into a load ring.

Typically, the annular ring is of L-shaped cross-section.

BRIEF DESCRIPTION OF THE DRAWINGS:
The invention will now be described with reference to the accompanying drawings in which:

Figure 1 illustrates a schematic arrangement of a conventional boring operation according to the prior art;

Figure 2(a) illustrates a schematic arrangement of a boring operation in accordance with the present invention; and

Figure 2(b) illustrates a perspective view of a vibration dampener of figure 2(a).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS:
A preferred embodiment will now be described in detail with reference to accompanying drawings. The preferred embodiment does not limit the scope and ambit of the invention. The description provided is purely by way of example and illustration.

Referring to the figure 2(a), In accordance with the present invention, there is provided a boring operation 200 comprising a machine spindle 202, an extending boring bar 204, an outer ring 205, a load ring 206, a setting ring 208, a tool holder 210, a tool 212 and a vibration dampener 214.

The configuration and the mechanism of the boring operation 200 is as follows:
The extending boring bar 204 is inserted into the machine spindle 202 and the extending boring bar 204 is adapted to pass through the outer ring 205 and the load ring 206. The tool holder 210 is inserted into the extending boring bar 204 which in turn accommodates a tool 212 in position. A workpiece is setup in the setting ring 208 and the load ring 206, coaxial to the tool 212.

The present invention finds its application in carrying out boring operation on workpieces (cylindrical objects) of longer lengths. The workpieces of longer lengths calls for the extending boring bar 204 of longer lengths which in turn calls for a plurality of load rings 206.

The increase in the length of the extending boring bar 204 causes overhang in the tool 212 which ultimately results in the generation of throw during boring operation. The generation of throw during boring operation produces chattering marks on the workpiece which finally results in the workpiece lacking precision. This design problem calls for the vibration dampener 214 to be inserted into the extending boring bar 204 and the vibration dampener 214 in turn adapted to insert into the load ring 206. The introduction of the vibration dampener 214 at the load ring 206 adds structural rigidity to the extending boring bar 204 which ultimately prevents the eccentricity of the tool 212 during boring operation.

Figure 2(b) illustrates a perspective view of a vibration dampener.

The vibration dampener 214 is an annular ring 214(a) of L-shaped cross section. The inner diameter of the annular ring 214(a) is slightly more than the diameter of the extending boring bar 204 to achieve a clearance fit which ultimately facilitates in free rotation of the extending boring bar 204. The outer diameter of the annular ring 214(a) is slightly less than the inner diameter of the load ring 206 to achieve a push fit. A circumferential edge CE of the annular ring 214(a) adapts to the surface of the load ring 206 in its assembled condition and arrests the movement of the vibration dampener 214.

Typically, the vibration dampener 214 is made up of brass.

TECHNICAL ADVANCEMENTS:
A vibration dampener for a machining operation has several technical advantages including but not limited to the realization of:
• a vibration dampener for boring operations to achieve better surface finish of the workpiece;
• a vibration dampener for boring operations to achieve long life of a tool;
• a vibration dampener for achieving precision in boring operations;
• a vibration dampener for increasing cutting speed and feed in boring operations;
• a vibration dampener which helps in finishing the boring operation at less time; and
• a vibration dampener to reduce noise in boring operations.

Although the invention has been described herein above with reference to the embodiments of the invention, the invention is not limited to the embodiments described herein above. It is to be understood that modifications and variations of the embodiments can be made without departing from the spirit and scope of the invention.