Title of Invention

A ROTARY TOOL FOR DRILLING AND METHOD OF DRILLING THEREOF

Abstract

This invention relates to rotary tools used for drilling blind a through hole in rubber like materials. For drilling through hole a drill body the axial hole and cutting edge at the open end is used. The material is cut along the axis of the hole and cut material flowed through the hole at the centre. For drilling blind hole the tool used for drilling through hole is used to drilled up to required depth and then said rotary tool is replaced by another tool which will remove already cut material from the bore hole by cutting the material in perpendicular direction of the axis of the bore hole and cut material flows through the hole provided along the axis of the tool.

Full Text

FORM 2 THE PATENTS ACT 1970 (39 of 1970) & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION (See Section 10; rule 13) TITLE OF THE INVENTION ROTARY TOOL FOR DRILLING AND METHOD OF DRILLING THEREOF 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 Dattatraya D Narhe and Sunil Dattatraya Sonawani 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 complete specification particularly describes the invention and the manner in which it is to be performed. FIELD OF INVENTION This invention relates to cutting tools for drilling blind and through hole in rubber and method of drilling blind hole in rubber. Cutting of rubber for making hole (blind or through) is very difficult with the normal cutting tools. A new cutting tool for this purpose has been developed to make holes in the rubber parts for the prototype applications. BACKGROUND OF INVENTION The elastic properties of Rubber make it difficult to be cut with normal cutting tools (drills etc). Rubber elasticity, also known as hyper elasticity, describes the mechanical behavior of many polymers, especially those with cross-linking. Invoking the theory of rubber elasticity, one considers a polymer chain in a cross-linked network as an entropic spring. When the chain is stretched, the entropy is reduced by a large margin because there are fewer conformations available. Therefore, there is a restoring force, which causes the polymer chain to return to its equilibrium or unstretched state, such as a high entropy random coil configuration, once the external force is removed. This is the reason why rubber bands return to their original state. There are lots of parts in the automobile industry which are made of rubber and to machine these for proto applications is another challenge. Earlier for any modification in the existing geometry of the rubber parts, used to do this with heated MS rods, e.g. if the hole on the existing part to be modified then one MS rod used to be heated to certain temp and then it used to be inserted in the part to enlarge the hole. This process had the following disadvantages :- 1. The foul smell of burning of rubber used to spoil the atmosphere. 2. The quality of the holes was very poor. 3. The desired accuracy levels were not met. So to counter these problems one new cutter is developed. Conventional through hole cutting tools cannot be used since the tools tends to shear the rubber material and removal of sliced material is also not efficient. These advantages can be overcome by designing new cutting tools which can drill blind and through holes efficiently in rubber by removing material from the hole without shearing the same. OBJECTS OF INVENTION The main object of this invention is to develop a tool which can be used for drill through hole in rubber like material. Another object of this invention is to develop a tool which can be used to drilling blind hole in rubber like material. Yet another object of this invention is to provide for a method of drilling blind hole in rubber material. SUMMARY OF INVENTION According to present invention a rotary tool provided for drilling through hole comprising, a drill body having first and second end, a hole extending along rotational axis of said drill body, an extended member disposed at said first end of the drill body, a shank disposed at said second end of the drill body, and a tip member engaged with said extended member. Another embodiment of the inventions a rotary tool provided for drilling blind hole comprising, a drill body having first and second end, said first end tapered inside to form a cutting edge, a hole extending along rotational axis of said drill body, and a shank disposed at said second end. In accordance of this invention a method of drilling blind hole in rubber material comprising steps of, attaching a rotary tool as claimed in claim 5 in machine spindle, inserting said rotary tool in said rubber material to required depth by rotating, removing said rotary tool from said rubber material and then from said machine spindle, attaching a rotary tool as claimed in either claim 1 or claim 4 in said machine spindle, inserting said rotary tool in said drilled hole by rotating, removing cut material from said drilled hole by rotation of said rotary tool to form a blind hole. BRIEF DESCRIPTION OF DRAWINGS Fig. 1 & Fig. 7 show the front view of the rotary tool used for drilling blind hole Fig. 2 & Fig. 8 show the side view of the rotary tool used for drilling blind hole Fig. 3 & Fig. 9 shows the plan view of the blind hole drilling tool Fig. 4 & Fig. 10 show the side view of the tip member (cutting edge) Fig. 5 & Fig. 11 show side view of the connecting rod Fig. 6 & Fig. 14 show the side view of the rotary tool used for drilling blind and through hole Fig. 12 shows the side view of the connecting rod Fig. 13 shows the cross sectional view of the connecting rod DETAILED DESCRIPTION OF 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. An embodiment of the present invention will now be explained with reference to the drawings as shown in Fig 1 to Fig. 4, the drill has a drill body (2) a tip member (4) and drill body includes a shank (1). The drill body has hole extending along the rotational axis. The shank (1) has a female threaded portion formed with in its end and extending a predetermined length along the rotational axis. The hole extending along the rotational axis of drill body communicate to threaded portion of the shank so that material flows freely through the drill body and can be removed through shank. The drill body further having an extended member (3) along the longitudinal axis and the terminating end of the extended member has a hole to engage the tip member (1). The tip member (4) is an elongated member having one end with aperture (4') to engage with the extended member on the drill body. The tip member is located perpendicular to the axis of the drill body. The length of the tip member varied according to the dimension of the hole required to be bored. The tip member is acting as a cutting edge for removing the rubber material by slicing the same. The tip member (4) is screwed to the extended member on the drill body through the recess (4') at one end where a screw engaged with the protrusion in extended member (3). The width of the tip member (4) having narrowed at free end (4") and widen at other end (4') screwed to the extended member on the drill body. Tip member (4) cut the material perpendicular to the axis of the hole and cut material flowed through the hollow portion of the cutting tool. Referring to the Fig. 5, a connecting rod connects the drill to the spindle. The connecting rod has a shank (6) at the lower portion and threaded upper part (5). The upper part has male threaded portion to engage in the thread portion of the drill. Figure 6 shows a rotary drill for drilling through holes in rubber material. The drill having a drill body (12) and a shank (10) to connect it to spindle. The drill body has a hole extending along the rotational axis and terminating at open end. The other end of the drill body is engaged with shank connected by a connection portion (11). The open end of the drill body is tapered inside (13) to form a cutting edge. The drill can be used to drilling through hole or blind hole in rubber material. Rotary tool cut the material along the axis of the hole. More details of constructional and dimensional features of rotary drill are given below. Referring to Fig 7 to 13, Fig. 7 is the front elevation view of the rubber-boring tool used for blind boring. This rubber-boring tool consists of two main parts. One of them contains the cutting tool attached to the top of the shank and other one connects the machine spindle with the first part. The part containing the cutting tool (tip member) has drill body and a lower shank denoted by dimension A in the right side view and dimension B in the front view of the tool. A is the distance between the two parallel and linear faces of the tool. The dimension B is a circular dimension on the bottom of the tool. The lower shank also contains an internal thread denoted by C. The height of the thread is denoted by D The height of drill body is denoted by F. The drill body is hollow and has an internal diameter denoted by dimension E. There is a fillet between the lower shank and the drill body denoted by Ra. The drill body also has extended member to which the cutting tool is screwed. The extended member is joined by a fillet to the drill body to a height of G. The thickness of the extended member is denoted by dimension H. The length of the extended member is denoted by K. The dimension J is the length of the tool excluding the length of the cutting tool (tip member) holding projection. There is also a hole on the upper face of the extended member to screw the cutting tool (tip member) with it. The diameter of the hole is denoted by L. The dimension P is the diameter of the drill body whose length is denoted by F. The thickness of the cutting tool (tip member) screwed to the projection is denoted by M. The dimension N is the elevation near the free end of the cutting tool (tip member). The edge of the cutting tool (tip member) is raised to a height of N for a distance of Z as in fig 8. Also the edge is inclined along the distance Z. The width of the cutting tool is denoted by T. The width of the projection is denoted by U. The fillet radius between the upper shank and the projection is denoted by Re. The extended member is connected with the drill body by an arc of radius Rc. The cutting tool (tip member) is given relief on both the directions of the tool. The relief on the longitudinal direction is given by radius Re. The relief on the transverse direction is denoted by radius Rb. The radius of the screw used to tighten the cutting tool (tip member) with the drill body is denoted by Rd. The cutting tool (tip member) is explained in detail in fig 9. The length of the cutting tool is denoted by Y. The cutting tool (tip member) is raised at the free end of the cutting tool to a height of N through a distance of Z. The dimension AB is the length of the cutting tool (tip member) resting on the face of the extended member. The distance between the center of the screw and the transverse edge of the extended member is denoted by dimension AC. The second part (connecting rod) of the rubber-boring tool connects the spindle with the first part of the tool. The dimensions A, B and C are same as explained in fig 1 except for the fact that C is an external thread in this part. This part has a lower shank of diameter Q and of height V. The lower shank is connected to the external thread by a portion of diameter B and height of W. The external thread above the shank of this part is denoted by C and its height is denoted by X. This second part has a hole of diameter S mm. Referring to fig. 13, the rubber-boring tool used for through boring has a cutting edge at open end of the drill body, which can be held in the machine spindle. The diameter of the cutting edge is denoted by Dl. The dimension (3 is the angle of the cutting edge of the tool. This angle is between the straight face of the tool and the taper given to introduce sharpness to the cutting edge of the tool. The height of the drill body is given by the dimension LI. The tool also has a hole of diameter D5 for a length of LI. The drill body of the tool is connected to shank by a cylinder of diameter D2. The diameter D2 is more than Dl. The height of the cylinder is denoted by L2. The shank is of length L3 and is of diameter D4. The shank also has a hole of diameter D3 which extends to a length of (L2 + L3). The dimension R is the fillet radius between drill body and shank. R is the also the fillet radius between the internal diameter D5 of the drill body with the shank of the tool. The chamfer on the top of the shank is for a depth of A and at an angle of pi with the top of the shank. METHOD OF DRILLING For Through Holes :- Referring to Fig. 6, this tool is made of one hollow pipe and sharpened at the end (rake angle). This cutter is held in the spindle of the drilling machine and it is inserted through the rubber part. The material is being cut and it flows through the hollow portion of cutting tool. The rake angle at the bottom of the tool enables easier removal of the material which is otherwise very difficult due to the elastic properties of rubber. The rake angle is preferably 10°, and it is an important parameter in drilling of rubber. For Blind Holes:- To make a blind hole, tool referred to fig. 6 used to cut the material up to the particular depth required. The material is being cut and it flows through the hollow portion of cutting tool. After reaching particular depth, the tool is removed. The cut material is remaining in the hole because the bottom portion of the cut material is not being separated. The material is separated only in vertical side and connected to the bottom. Then the tool referred to fig 1 to 5 is used to remove the material from the hole. The fitment of this tool in the drilling machine spindle is same as the earlier one. The cutting edge or the tip can be adjusted with the help of adjustment scale for different diameters. The material inside the hole is sliced by the rotating action of the tool and cut material is flowed through the hollow portion of cutting tool. The tool is lowered to slice the material and remove it from the hole. The boring is continued till the tool reaches the above particular level where the cutting edge cut and separate the bottom connected portion of the vertically cut material. 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 rotary tool comprising, a drill body having first and second end, a hole extending along rotational axis of said drill body, an extended member disposed at said first end of the drill body, a shank disposed at said second end of the drill body, and a tip member engaged with said extended member. 2. A rotary tool as claimed in claim 1 wherein said extended member located on wall of the drill body and extending in lengthwise direction and terminating end of said extended member engaged with said tip member. 3. A rotary tool as claimed in claim 1 wherein said tip member having first and second end, said second end provided an aperture to engage with said extended member and said tip member is located perpendicular to the axis of said drill body. 4. A rotary tool comprising, a drill tool and a connecting rod, said drill tool having a drill body with first and second end, a hole extending along rotational axis of said drill body, an extended member disposed at first end of the drill body, a shank disposed at second end of the drill body, a tip member engaged with said extended member, and said connecting rod having a shank disposed with threaded upper part to engage with said drill tool. 5. A rotary tool comprising, a drill body having first and second end, said first end tapered inside to form a cutting edge, a hole extending along rotational axis of said drill body, and a shank disposed at said second end. 6. A method of drilling blind hole in rubber material comprising steps of, attaching a rotary tool as claimed in claim 5 in machine spindle, inserting said rotary tool in said rubber material to required depth by rotating, removing said rotary tool from said rubber material and then from said machine spindle, attaching a rotary tool as claimed in either claim 1 or claim 4 in said machine spindle, inserting said rotary tool in said drilled hole by rotating, removing cut material from said drilled hole by rotation of said rotary tool to form a blind hole. 7. A method as claimed in claim 5, wherein said rotary tool cut the material along the axis of the hole. 8. A method as claimed in either claim 1 or claim 4, wherein said rotary tool cut the material in perpendicular to the axis of the hole. 9. A rotary tool as substantially as herein described with reference to accompanying drawings 10. A method of drilling substantially as herein described with reference to accompanying drawings ABSTRACT Rotary Tool For Drilling And Method Of Drilling Thereof This invention relates to rotary tools used for drilling blind a through hole in rubber like materials. For drilling through hole a drill body the axial hole and cutting edge at the open end is used. The material is cut along the axis of the hole and cut material flowed through the hole at the centre. For drilling blind hole the tool used for drilling through hole is used to drilled up to required depth and then said rotary tool is replaced by another tool which will remove already cut material from the bore hole by cutting the material in perpendicular direction of the axis of the bore hole and cut material flows through the hole provided along the axis of the tool. Fig 7

Documents:

2302-MUM-2007-ABSTRACT(28-12-2011).pdf

2302-MUM-2007-ABSTRACT(GRANTED)-(25-3-2013).pdf

2302-mum-2007-abstract.doc

2302-mum-2007-abstract.pdf

2302-MUM-2007-CLAIMS(AMENDED)-(15-3-2013).pdf

2302-MUM-2007-CLAIMS(AMENDED)-(22-3-2013).pdf

2302-MUM-2007-CLAIMS(AMENDED)-(28-12-2011).pdf

2302-MUM-2007-CLAIMS(GRANTED)-(25-3-2013).pdf

2302-MUM-2007-CLAIMS(MARKED COPY)-(15-3-2013).pdf

2302-MUM-2007-CLAIMS(MARKED COPY)-(22-3-2013).pdf

2302-mum-2007-claims.doc

2302-mum-2007-claims.pdf

2302-MUM-2007-CORRESPONDENCE(3-1-2012).pdf

2302-mum-2007-correspondence(6-12-2007).pdf

2302-MUM-2007-CORRESPONDENCE(IPO)-(25-3-2013).pdf

2302-mum-2007-correspondence-received.pdf

2302-mum-2007-description (complete).pdf

2302-MUM-2007-DESCRIPTION(GRANTED)-(25-3-2013).pdf

2302-MUM-2007-DRAWING(28-12-2011).pdf

2302-MUM-2007-DRAWING(GRANTED)-(25-3-2013).pdf

2302-mum-2007-drawings.pdf

2302-MUM-2007-FORM 1(3-1-2012).pdf

2302-MUM-2007-FORM 13(28-12-2011).pdf

2302-mum-2007-form 18(6-12-2007).pdf

2302-MUM-2007-FORM 2(GRANTED)-(25-3-2013).pdf

2302-MUM-2007-FORM 2(TITLE PAGE)-(GRANTED)-(25-3-2013).pdf

2302-mum-2007-form 8(6-12-2007).pdf

2302-mum-2007-form 9(6-12-2007).pdf

2302-mum-2007-form-1.pdf

2302-mum-2007-form-2.doc

2302-mum-2007-form-2.pdf

2302-mum-2007-form-26.pdf

2302-mum-2007-form-3.pdf

2302-MUM-2007-GENERAL POWER OF ATTORNEY(15-3-2013).pdf

2302-MUM-2007-GENRAL POWER OF ATTORNEY(28-12-2011).pdf

2302-MUM-2007-MARKED COPY(28-12-2011).pdf

2302-MUM-2007-REPLY TO EXAMINATION REPORT(28-12-2011).pdf

2302-MUM-2007-REPLY TO HEARING(15-3-2013).pdf

2302-MUM-2007-REPLY TO HEARING(22-3-2013).pdf

2302-MUM-2007-SPECIFICATION(AMENDED)-(28-12-2011).pdf

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