Title of Invention	DRILLING TOOL OR MILLING TOOL AND METHOD FOR DERTERMINING THE ABSOLUTE CLEARANCE ANGLE OF THE FLANK REGIONS AN INSERT
Abstract	Drilling tool or milling tool with a tool support and atleast two inserts—mounted on the face (front side) of the tool support/carrier in each of the recesses-with a cutting face, which is bordered by the cutting edges, whereby atleast one insert posseses at least one interrupted/discontinued cutting edge—formed by an offset/protuberanee—has a contact surface and lateral surfaces which are provided under a positive clearanee angle, whereby every point of an active cutting edge of an insert mounted on the face defines a spiral or helical space curve with well prescribed axial drill ing -feed or milling feed (i ) characteriaed in that atleast the i lank region—adjacent to this active cutting edge-is formed by a large number of straight lines--lying perpendiculsr to the cutting edge—of which each space curve, developed into a straight line, is inclined under an effective positive (Clearence j - ang le "a" with reference to the space curve corresponding to a drilling feed or milling feed (f ) .

Title of Invention

DRILLING TOOL OR MILLING TOOL AND METHOD FOR DERTERMINING THE ABSOLUTE CLEARANCE ANGLE OF THE FLANK REGIONS AN INSERT

Abstract

Drilling tool or milling tool with a tool support and atleast two inserts—mounted on the face (front side) of the tool support/carrier in each of the recesses-with a cutting face, which is bordered by the cutting edges, whereby atleast one insert posseses at least one interrupted/discontinued cutting edge—formed by an offset/protuberanee—has a contact surface and lateral surfaces which are provided under a positive clearanee angle, whereby every point of an active cutting edge of an insert mounted on the face defines a spiral or helical space curve with well prescribed axial drill ing -feed or milling feed (i ) characteriaed in that atleast the i lank region—adjacent to this active cutting edge-is formed by a large number of straight lines--lying perpendiculsr to the cutting edge—of which each space curve, developed into a straight line, is inclined under an effective positive (Clearence j - ang le "a" with reference to the space curve corresponding to a drilling feed or milling feed (f ) .

Full Text	The invention pertains to a drilling tool or milling tool with a tool support and atleast two inserts—mounted in each pocket on the face (front side) of the tool support/Carrier—with a cutting face, which is defined/bounded by cutting edges, whereby atleast one insert possesses atleast one discontinuous cutting edge formed by an offset (protuberance), one contact surface, and lateral flanks, which are provided under positive clearanee angle, whereby every point of an at tive cutting edge of an insert mounted on the front side defines an helical space curve for precisely specified dri1ling feed/mil 1 ing -feed ( i ) . The invention further deals with a method for determining the absolute clearance angle of the flank regions which border on to the active cutting edge of an insert in a drilling tool or milling tool of the type mentioned earlier. From the state of art technology, suitable drilling tools are familier which are meant for making bore holes in solid material. o These tools have shank with atleast two inserts staggered by 180 and mounted in commensurate pockets. The inserts ^re mounted on the shank in varied radial distance so that the working regions overlap themselves in part, and border an to each other. If need be, even more than two inserts can be mounted on the front 53.de at different radial spacings. The same point niso holds good for face-mill cutters with front side mounted inserts. The inserts are available in manifold basic shapes, e.g. as hexagonal. octagonal, pentagonal, trianqular, rhombic. and rectangular inserts, partly even with enlarged corner/nose angle. For the purpose of drilling or milling, especially the inserts angle bisectors (median 1ines ) of the engaged bits of each indexable insert sr& mounted parallel to the drill axis, or under o «t slight tilt of maximum 2 . You can also see the description of inserts meant for drilling in the publication WO 93/0 28 24. These inserts possess atleast three corners/noses adjacent to the cutting face, and cutting edges lying between two consecutively arranged corners/noses. Of these, atleast one of the cutting edges has atleast two projected cutting tips. All inserts used on the front side (face) of the tool holder for It is therefore the task of the present invention to optimise the initially mentioned drilling tool or milling tool by means of a better stabilisation of the wedge formed between the cutting face and the flank. For this purpose, a procedural method should be specified for determining the absolute angle of the flank region bounded by the active cutting edge. The task to be solved should take stock of the entire insert geometries which are used on the front side on a drilling tool or milling cutter irrespective of the location where offset/protuberance (cutting edge nose ) is provided on the active cutting edge. First of all, in case of such inserts— which should be used in the central region of a dri11 —the pressure that results on the f lank during dri11ing should be maintained at minimum possible level. In case of milling, the task should be solved in particular with angular mi 11ing cutters having bigger axial angle. For solving the afore-mentioned task, the drilling tool or mi 11ing tool of the type mentioned earlier is characterised by the fact that atleast the flank region, adjacent to the active cutting edge, is formed by a number of straight lines perpendicular to the cutting edge of which each space curve— developed/unrolled into straight line--is inclined with an effective positive (clearance) angle with reference to the space curve corresponding to a drilling feed or milling feed. Due to this measure, each flank, of the front-side mounted inserts along the entire cutting edge—especially in the region of cutting edge tips/point—gets adapted the surface sres—that results from the rotation of the drill and the a>:ial feed--namely the drilled hole base or the milled hole base, in such a way that at every location, it gives rise to an effective actual positive clearance angle. This effective positive clearance angle should preferably o o o be lower than 15 , that too 5 to 9 in particular. eventually into a straight 1ine (in one plane) that 1 ieE in a plane perpendicular to the drilling teed or milling feed. Due to the associated rotation of these straight 1ines by the on initiating the developed view (layout of the respective The invention is explained-about further with the help of Figures shown in the accompanying drawings. What each Figure shows is mentioned below: Figure i shows spatial curves—laid out on a plane—that result from sole consideration of the clearance angle, and under common reckoning of the sum of the clearanee angle and the feed of the tool circle 11 which is run through by the point 12 of the cutting edge. If the feed of the drill and/or of the insert during obtain an effective clearance angle, the "clearanee angle deficiency hich crops up -from the dr il 1 feed, which is indicated bv the straight 1ine 15, which shows an objective clearanee ang]e b—with reference to the stationary insert--for each clearanee angle portion below a catting edge point. In continued dri11 application„ such an effective clearance angle of the desired type can be ascertained with reference to the feed independent of the f lank contour (out1ine) of the insert 10 in any given case. The sections A and B derived from Figure 5 show different contours 16 of the flank below the cutting edge point 12. WE CLAIM: 1. Drilling tool or milling tool with a tool support and atleast two inserts—mounted on the face (front side) of the tool support/carrier in each of the recesses-with a cutting face, which is bordered by the cutting edges, whereby atleast one insert posseses at least one interrupted/discontinued cutting edge—formed by an offset/protuberanee—has a contact surface and lateral surfaces which are provided under a positive clearanee angle, whereby every point of an active cutting edge of an insert mounted on the face defines a spiral or helical space curve with well prescribed axial drill ing -feed or milling feed (i ) characteriaed in that atleast the i lank region—adjacent to this active cutting edge-is formed by a large number of straight lines--lying perpendiculsr to the cutting edge—of which each space curve, developed into a straight line, is inclined under an effective positive (Clearence j - ang le "a" with reference to the space curve corresponding to a drilling feed or milling feed (f ) . 2. Drilling — or milling tool as shown in Figure i characterised by the fact that the effective clearanee angle (a) is less that o o o 15 , preferably between 5 and 9 3. Dri11ing- or milling tool as Claimed in 1 or 2, characterised by the fact that below a flank region adjacent to the cutting region, yet another flank region is provided under a higher clearanee angle than the absolute angle of the first flank region. 4. Method for determining the absolute clearanee angle of the f1ank regions which border on to the active cutting edge of an insert on a drilling or mi 11 ing tool as c 1 aimed in 1, characterised by the fact that for each point of an active cutting edge of an insert mounted on the face, the spiral- or helical space curve is ascertained for the well-specified maximum axial drilling- or milling feed {f), developed into straight 1ine, and—in addition to the effective clearanee angle—the absolute clearance angle is determined—also from the inc1ination of these straight lines with reference to a plane perpendicular to thedri11ing- or milling feed (f ) — for every flank region located below the specified point.

Full Text

The invention pertains to a drilling tool or milling tool with a tool support and atleast two inserts—mounted in each pocket on the face (front side) of the tool support/Carrier—with a cutting face, which is defined/bounded by cutting edges, whereby atleast one insert possesses atleast one discontinuous cutting edge formed by an offset (protuberance), one contact surface, and lateral flanks, which are provided under positive clearanee angle, whereby every point of an at tive cutting edge of an insert mounted on the front side defines an helical space curve for precisely specified dri1ling feed/mil 1 ing -feed ( i ) .
The invention further deals with a method for determining the
absolute clearance angle of the flank regions which border on to
the active cutting edge of an insert in a drilling tool or
milling tool of the type mentioned earlier.
From the state of art technology, suitable drilling tools are
familier which are meant for making bore holes in solid material.
o These tools have shank with atleast two inserts staggered by 180
and mounted in commensurate pockets. The inserts ^re mounted on

the shank in varied radial distance so that the working regions overlap themselves in part, and border an to each other. If need be, even more than two inserts can be mounted on the front 53.de at different radial spacings.
The same point niso holds good for face-mill cutters with front side mounted inserts.
The inserts are available in manifold basic shapes, e.g. as hexagonal. octagonal, pentagonal, trianqular, rhombic. and rectangular inserts, partly even with enlarged corner/nose angle. For the purpose of drilling or milling, especially the inserts

angle bisectors (median 1ines ) of the engaged bits of each
indexable insert sr& mounted parallel to the drill axis, or under
o «t slight tilt of maximum 2 .

You can also see the description of inserts meant for drilling in the publication WO 93/0 28 24. These inserts possess atleast three corners/noses adjacent to the cutting face, and cutting edges lying between two consecutively arranged corners/noses. Of these, atleast one of the cutting edges has atleast two projected cutting tips.
All inserts used on the front side (face) of the tool holder for

It is therefore the task of the present invention to optimise the initially mentioned drilling tool or milling tool by means of a better stabilisation of the wedge formed between the cutting face and the flank. For this purpose, a procedural method should be

specified for determining the absolute angle of the flank region bounded by the active cutting edge. The task to be solved should take stock of the entire insert geometries which are used on the front side on a drilling tool or milling cutter irrespective of the location where offset/protuberance (cutting edge nose ) is provided on the active cutting edge. First of all, in case of such inserts— which should be used in the central region of a dri11 —the pressure that results on the f lank during dri11ing should be maintained at minimum possible level. In case of milling, the task should be solved in particular with angular mi 11ing cutters having bigger axial angle.
For solving the afore-mentioned task, the drilling tool or mi 11ing tool of the type mentioned earlier is characterised by the fact that atleast the flank region, adjacent to the active cutting edge, is formed by a number of straight lines perpendicular to the cutting edge of which each space curve— developed/unrolled into straight line--is inclined with an effective positive (clearance) angle with reference to the space curve corresponding to a drilling feed or milling feed. Due to this measure, each flank, of the front-side mounted inserts along the entire cutting edge—especially in the region of cutting edge tips/point—gets adapted the surface sres—that results from the rotation of the drill and the a>:ial feed--namely the drilled hole base or the milled hole base, in such a way that at every

location, it gives rise to an effective actual positive clearance
angle. This effective positive clearance angle should preferably
o o o
be lower than 15 , that too 5 to 9 in particular.

eventually into a straight 1ine (in one plane) that 1 ieE in a plane perpendicular to the drilling teed or milling feed.

Due to the associated rotation of these straight 1ines by the

on initiating the developed view (layout of the respective

The invention is explained-about further with the help of Figures shown in the accompanying drawings. What each Figure shows is mentioned below:
Figure i shows spatial curves—laid out on a plane—that result from sole consideration of the clearance angle, and under common reckoning of the sum of the clearanee angle and the feed of the tool

circle 11 which is run through by the point 12 of the cutting edge. If the feed of the drill and/or of the insert during

obtain an effective clearance angle, the "clearanee angle deficiency hich crops up -from the dr il 1 feed, which is indicated bv the straight 1ine 15, which shows an objective clearanee ang]e b—with reference to the stationary insert--for each clearanee angle portion below a catting edge point. In continued dri11 application„ such an effective clearance angle of the desired type can be ascertained with reference to the feed independent of the f lank contour (out1ine) of the insert 10 in any given case. The sections A and B derived from Figure 5 show different contours 16 of the flank below the cutting edge point 12.

WE CLAIM:
1. Drilling tool or milling tool with a tool support and atleast
two inserts—mounted on the face (front side) of the tool
support/carrier in each of the recesses-with a cutting face,
which is bordered by the cutting edges, whereby atleast one
insert posseses at least one interrupted/discontinued cutting
edge—formed by an offset/protuberanee—has a contact surface and
lateral surfaces which are provided under a positive clearanee
angle, whereby every point of an active cutting edge of an insert
mounted on the face defines a spiral or helical space curve with
well prescribed axial drill ing -feed or milling feed (i )
characteriaed in that atleast the i lank region—adjacent to this
active cutting edge-is formed by a large number of straight
lines--lying perpendiculsr to the cutting edge—of which each
space curve, developed into a straight line, is inclined under an
effective positive (Clearence j - ang le "a" with reference to the
space curve corresponding to a drilling feed or milling feed
(f ) .
2. Drilling — or milling tool as shown in Figure i characterised
by the fact that the effective clearanee angle (a) is less that
o o o
15 , preferably between 5 and 9

3. Dri11ing- or milling tool as Claimed in 1 or 2,
characterised by the fact that below a flank region adjacent to
the cutting region, yet another flank region is provided under
a higher clearanee angle than the absolute angle of the
first flank region.
4. Method for determining the absolute clearanee angle of the
f1ank regions which border on to the active cutting edge of an
insert on a drilling or mi 11 ing tool as c 1 aimed in 1,
characterised by the fact that for each point of an
active cutting edge of an insert mounted on the face, the
spiral- or helical space curve is ascertained for the
well-specified maximum axial drilling- or milling feed
{f), developed into straight 1ine, and—in addition to
the effective clearanee angle—the absolute clearance angle
is determined—also from the inc1ination of these straight
lines with reference to a plane perpendicular to thedri11ing-
or milling feed (f ) — for every flank region located below
the specified point.

Documents:

259-mas-1998 abstract.pdf

259-mas-1998 claims.pdf

259-mas-1998 correspondence others.pdf

259-mas-1998 description (complete).pdf

259-mas-1998 drawings.pdf

259-mas-1998 form-1.pdf

259-mas-1998 form-26.pdf

259-mas-1998 form-4.pdf

259-mas-1998 petiiton.pdf

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Patent Number

196417

Indian Patent Application Number

259/MAS/1998

PG Journal Number

30/2009

Publication Date

24-Jul-2009

Grant Date

05-Jan-2006

Date of Filing

10-Feb-1998

Name of Patentee

M/S. WIDIA GMBH

Applicant Address

MUNCHENER STRASSE 90, D-45145, ESSEN,

Inventors:

#	Inventor's Name	Inventor's Address
1	MR. MARKUS HEINLOTH,	C/O WIDIA GMBH, MUNCHENR STRASSE, 90, D-4300, ESSEN 1,
2	MR. WIDIA REINHOLD	C/O WIDIA GMBH, MUNCHENR STRASSE, 90, D-4300, ESSEN 1,
3	MR. KLAUS RAMOLD,	C/O WIDIA GMBH, MUNCHENR STRASSE, 90, D-4300, ESSEN 1,

PCT International Classification Number

B23B 51/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA