Information
-
Patent Grant
-
6811362
-
Patent Number
6,811,362
-
Date Filed
Tuesday, September 11, 200123 years ago
-
Date Issued
Tuesday, November 2, 200420 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Shewchuk IP Services
- Shewchuk; Jeffrey D.
-
CPC
-
US Classifications
Field of Search
US
- 407 47
- 407 49
- 407 51
- 407 56
- 144 230
- 144 218
- 144 229
- 144 231
- 076 115
- 409 138
- 409 234
- 082 111
- 082 46
-
International Classifications
-
Abstract
A method for reusing profile insert blades maintains axial, radial and profile dimensions of a cutting tool. The method includes duplicating an original profile on a used profile insert blade by sharpening a profile edge of the used profile insert blade to form a sharpened profile edge with a new profile that is shifted longitudinally along a length of the profile cutter blade relative to an original profile position. Material is removed from a reference edge of the sharpened profile insert blade to form a new reference edge, for positioning the resharpened blade in a longitudinally changed position so that the new adjusted profile has similar axial, radial and profile dimensions as compared to the original profile.
Description
BACKGROUND OF THE INVENTION
The invention relates to a cutterhead or router bit, having profiled insert blades or knives, each having a cutting edge for use in cutting a broad range of nonferrous materials. More specifically, the invention relates to a cutterhead or router bit having profiled insert blades or knives that can be sharpened by re-profiling the cutting edge without changing the original profile, the original cutting diameter of the tool in the radial direction, or the original location of the cutting edge (height or thickness) relative to the axis. The present invention relates to a method and apparatus for sharpening inserts through re-profiling to allow reuse of the insert blade while maintaining the original cutting profile and dimensions.
Generally, cutterheads and router bits are rotating cutting tools designed to perform precision cutting on planar or curved surfaces of a workpiece. Insert cutting tools, comprising one design family of cutting tools, utilize removable cutting blades referred to as knives or inserts. Inserts are commonly, but not exclusively, made from relatively small blanks of various grades of carbide, tantung, or high speed steel ceramic and the like. Some inserts have an insert body with an attached, generally brazed, cutting tip material applied, such as mono or poly-crystalline diamond, other types of manufactured diamond and the like, the cutting materials described above, or other similar materials. Typically, any combination of insert designs may be used on the same cutting tool body.
Cut angles used in metal working are generally different from woods, plastics and other nonferrous materials. Wood varies dramatically in density and grain structure within small areas of a board. Wood knots and wood grain variations provide small visible differences in the wood surface, which may have dramatic effects on blade angles and cutting speeds. Additionally, these wood grain differences vary widely between species of wood. The hook, shear, and back clearance angles are chosen according to the hardness, density and grain variation of the material to be cut. Typically, cutters for metals use negative hook angles. Hard woods, such as hard maple, may also use negative hook angles. Generally, woods, plastics and nonferrous metals have a broader range of possible hook angles, of which the angles for metal working is a small subset.
Industries using wood and related materials, such as MDF, plastics and similar non-ferrous materials, almost universally employ insert-type tools for precision cutting of a profile or a design. Typically, within the family of removable insert cutting tools, the cutting edge extends beyond the cutting tool body peripheral surface as the tool with the inserts rotates on a shank or machine shaft. As the cutting edges contact the workpiece, a chip or shaving is removed from the workpiece. When each blade contacts the workpiece, the blade removes a shaving. The thickness of each shaving depends upon the advance rate of the workpiece and the rotational speed of the cutting tool. The surface of the wood or plastic (workpiece) that is being cut is fed against or in the same direction (commonly referred to as “climb” or “convention” cutting) the cutting tool while the tool rotates.
During use, the inserts may wear down or become damaged. Dull and damaged inserts may damage the workpiece. Thus, cutting inserts require frequent inspection, adjustment, and replacement.
Operating costs depend in large part on how long the insert remains sharp and free of damage before it must be replaced. The operating costs of machines which utilize the thin blades are effected by the cost of the blades, the length of downtime intervals which are required to replace a used blade with a fresh blade, the length of downtime interval required to change the orientation of a blade having several cutting edges, the shape and complexity of the cutting surface, the type of material to be cut, and so on. The length of downtime interval required for exchange or reorientation of blades can be reduced by using holders which can be rapidly inserted into or removed from the body portion of the tool. However, such holders typically assume a singular position for the blade relative to the holder, such that a re-sharpened blade would require adjustment of the entire cutterhead.
The cost of inserts can be kept low by using polygonal pieces of cutting material having one or more cutting edges. However, profile cutting blades typically have a single cutting surface with a unique shape, such that the cost of the blades is significantly higher than the stock blades. While multi-edge indexable inserts can be rotated so that when one cutting edge becomes dull an unused cutting edge can be rotated into position, the profiled inserts typically have a single cutting edge (in some cases two opposing cutting edges) with a unique profile shape. The cost of the profiled inserts is significantly higher than ordinary indexable inserts.
Typically, profiled inserts assume a singular position for the insert relative to the tool body such that the re-profiled or re-faced inserts are changed in one or more dimensions relative to the original insert cutting edge. It is presently possible to re-profile open profiles on inserts without changing the profile; however, the cutting diameter and axial position of the profile cutting edge will change relative to the original cutting edge. It is also possible to sharpen an insert cutting edge by face grinding the insert; however, the profile shape, the radial diameter and the axial position of the cutting edge will change. Thus, the profile inserts are typically designed to be disposable, single-use items.
BRIEF SUMMARY OF THE INVENTION
The present invention includes a rotating cutting tool body (cutterhead or router bit) having one or more precision machined pockets or insert slots for receiving a profiled insert or blade. The profiled insert has a top edge, a cutting profile, a reference edge, and a ramp edge, (not always distinct from one another) and is held in place by a wedge and attachment means. The ramp edge of the profiled insert is aligned against a ramp wall of a pocket in the cutting tool body, and the reference edge is aligned with a reference face of the cutting tool body. As the profiled insert becomes dull, the insert is removed and re-profiled, including the removal of blade material along the cutting profile and along the reference edge to establish a new cutting profile and a new reference edge. The re-profiled insert may then be placed into the pocket in the cutting tool body and advanced along the ramp wall of the cutting tool pocket until the new reference edge of the insert is aligned with the reference face of the cutting tool body. Thus located, the cutting tool with re-profiled inserts maintains a constant diameter, constant profile cutting edge, and a constant axial position.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a top plan view of a cutterhead of the present invention.
FIG. 2
is a side plan view of the cutterhead of FIG.
1
.
FIG. 3
is a perspective view of a cutterhead of the present invention.
FIG. 4
is a side view of a profile insert in situ with a cross sectional portion of the cutterhead of FIG.
1
.
FIG. 5
is a schematic side view of a cutterhead of the present invention.
FIG. 6
is a schematic side view of a router bit according to the present invention.
FIG. 7
is a schematic bottom view of the router bit of FIG.
6
.
FIG. 8
is a perspective view of the router bit of FIG.
6
.
FIG. 9
is a schematic side view of the router bit of FIG.
6
.
FIG. 10
is a side plan view of the router bit of FIG.
6
.
FIG. 11
is a side plan view of a stepped-edge insert.
While the above-identified illustrations set forth preferred embodiments, numerous embodiments of the present invention have been designed and contemplated, some of which are noted in the discussion. In all cases, this disclosure presents the illustrated embodiments of the present invention by way of representation and not limitation. Numerous other minor modifications and embodiments can be devised by those skilled in the art which fall within the scope and spirit of the principles of this invention.
DETAILED DESCRIPTION
FIG. 1
shows a cutterhead
10
having a substantially circumferential body
12
. The body
12
has a shoulder
14
around a bore
16
to fixably mount the cutterhead
10
to a rotating spindle, shank or machine shaft (not shown) in order to cut or shape material. The bore
16
extends through the body
12
along a central axis
15
which extends through the center of mass of the cutting tool. The cutterhead
10
has one or more inserts slots, wings or pockets
18
such as the three circumferentially spaced insert pockets
18
shown. Each insert pocket
18
has a guide mechanism or ridge
20
for guiding an insert
22
into position in the pocket
18
. Each insert pocket
18
is sized to receive an insert
22
, a wedge
24
, clamps
26
and clamping screws
28
. During use, the insert
22
extends beyond the peripheral surface of the cutting tool body
12
as the cutting tool
10
rotates so as to contact the workpiece and perform the cut.
Each insert pocket
18
has a leading insert wall
30
, a ramp wall
32
, and a trailing insert wall
34
. An access face
36
extends from the circumferential edge
38
to the insert pocket
18
to expose the insert
22
to a non-ferrous material or workpiece and allow the shavings or chips from the workpiece to be released.
The guide mechanism, such as ridge
20
on the insert ramp wall
32
, preferably extends the full length of the pocket
18
of the cutting tool
10
for ensuring proper safety in holding the insert
22
in place. Generally, the insert
22
has a corresponding guide, such as a groove (not shown). The ridge
20
/groove relation also provides a safety mechanism for preventing the insert
22
from slipping radially during use. In the preferred embodiment, the ridge
20
is a convex ridge, and the insert
22
has a corresponding concave groove.
The insert pocket
18
has a ramp wall
32
, which slants outward away from the bore
14
defining a ramp angle A relative to the central axis
15
. The ramp wall
32
has one or more threaded bore holes
40
sized to receive one or more clamping screws
28
. The access face
36
preferably extends outward from the supply face
42
to define the same angle A with respective central axis
15
, such that both the access face
36
and the ramp wall
32
extend at the ramp angle A relative to the central axis
15
. The angle of the access face
36
is not critical. The access face
36
provides clearance for chips and shavings of the workpiece to be released. As shown with respect to the router bit of
FIGS. 6-10
(discussed supra), the access area may be curved or cupped, such that the angle varies along the curve of the access area. The access face may be of any shape or configuration, provided an end of the access face
36
exposes the insert
22
, because the access face
36
provides clearance for chips and debris.
Generally, the inserts
22
are polygonal pieces of carbide (or materials previous mentioned) having one or more cutting edges. As shown in the present invention, the inserts
22
are unitary pieces flat sheet having a singular cutting edge. However, some blades may be formed from a sheet steel stock tipped with a harder substance, such as mono or poly-crystalline diamond.
As best shown in
FIGS. 3 and 4
, the insert
22
has a trailing face
44
, a leading face
46
, a radial or profile edge
48
, a ramp edge
50
, a supply edge
52
, and a reference edge
54
(shown in FIGS.
3
and
4
). The trailing face
44
and the leading face
46
are substantially parallel. The supply edge
52
and the reference edge
54
need not be parallel. The ramp edge
50
mates with the ramp wall
32
of the cutterhead
10
. The radial edge
48
defines a profile shape for shaping the workpiece. Generally, the radial edge
48
may define a non-linear cutting edge, though for some purposes the cutting edge may be straight. The reference edge
54
is used to align the cutting insert
22
with the reference face
56
(shown in
FIG. 2
)
The orientation of the insert
22
in the cutterhead defines four angles: a ramp angle A, a hook angle B, a shear angle C, and a back clearance angle D. As previously mentioned, the ramp angle A is defined as the angle between the ramp wall
32
and the central axis
15
. Generally, ramp angle A causes the insert
22
to extend further radially as the insert
22
is advanced axially against the ramp wall
32
. Depending on the shape of the profile insert
22
and the size of the cutterhead
10
, the ramp angle A may vary between 1 and 89 degrees. A shallow profile on the profile insert
22
requires a small ramp angle A, whereas a deep profile on the insert
22
requires a larger ramp angle A.
The hook angle B is the angle at which the radial edge
48
of the insert
22
attacks the surface the workpiece as determined by the profile edge
48
relationship to the central axis
15
of the cutterhead
10
. Generally, the hook angle B is the angle defined by the intersection of a line extending from the central axis
15
to the leading point of the insert
22
. In a cross-section perpendicular to the axis
15
, the hook angle B is the angle between a line intersecting the cutterhead axis and the cutting tip of the insert
22
and a line along the leading face
46
of the insert
22
. Because the circumferential location of the cutting tip of the insert
22
varies along the radial profile edge, the hook angle B of the insert
22
varies along the radial profile edge
48
(radius of cutting point, i.e. cos(C)). In
FIG. 1
, the hook angle B at the reference edge
54
is roughly 20 degrees. The hook angle B may be varied by machining the cutterhead
10
to have a different angle according to the material to be cut. Generally, the harder the material to be cut, the smaller the hook angle B. Metals and hard maples, for instance, typically require a negative hook angle B.
Generally, the hook angle B varies according to the density or hardness of the material. For hard metals, the hook angle is generally limited to between −5 degrees and 5 degrees. For a small minority of softer metals, the hook angle B varies from −5 degrees to 10 degrees. For non-ferrous metals and woods, the hook angle B typically ranges from −5 degrees to 60 degrees.
The shear angle C and back clearance angle D are more clearly visible in
FIGS. 3-5
. The shear angle C is defined by the intersection of a line parallel to the central axis
15
with the leading face
46
of the insert
22
. During each rotation of the cutterhead
10
, the insert blades
22
contact the workpiece at a single point, which moves during the cut, away from the supply edge
52
and toward the reference edge
54
. Each time the insert
22
rotates through the workpiece, a small chip is sliced away from the workpiece surface. The shear angle C ensures that only a single point along the profile edge
48
of the insert
22
is cutting the workpiece at any given instant.
The back clearance angle D is the angle at which the
44
profile edge
48
of the cutting insert
22
recedes from the furthest radially extending point of the leading face
46
of the cutting insert
22
. Said another way, the back clearance angle D is defined by a tangent line extending from the cutting point of the profiled insert
22
relative to the surface of the profile edge
48
of the cutting insert
22
. The sharpness or bluntness of the cutting insert
22
is determined by this back clearance angle D, which is created by removing metal from the trailing edge of the cutting insert
22
during grinding. The clearance angle D prevents the insert
22
from causing the workpiece to burn. Generally, for metals, a clearance angle D is in the range of 5-7 degrees. For nonferrous metals and woods, generally the clearance angle D may range from 5 to 15 degrees.
The access faces
36
, which provide chip clearance for chips and shavings from a workpiece, also exposes the leading face
46
of the cutting insert
22
to the workpiece when the cutterhead
10
is rotated in the direction E. The wedge
24
and clamps
26
exert lateral force against the leading face
46
of the insert
22
to prevent unwanted motion of the insert
22
during use. The clamping screws
28
fix the clamps
26
and the wedge
24
into place next to the insert
22
within the insert pocket
18
. Generally, the clamping screws
28
may be any device for releasably attaching the clamps
26
and wedge
24
into place. In the preferred embodiment, the clamping screws
28
are hex screws which insert through the clamps
26
and into threaded holes
40
in the insert pockets
18
on the body
12
of the cutterhead
10
. The holes
40
in the insert pocket
18
are sized to receive a threaded clamping screw
28
and extend into the body
12
perpendicular to the surface of the ramp wall
32
. Tightening the clamping screws
28
exerts a horizontal force on the wedge
24
, which in turn exerts a horizontal force on the insert
22
. Thus, the insert
22
is held in place during use by the horizontal force and an opposing normal force exerted on the insert
22
by the trailing wall
34
of the insert pocket
18
.
The cutterhead
10
described herein, is primarily designed for use with non-ferrous materials, such as plastics, woods, and non-ferrous metals. Wood varies dramatically in density and grain structure within small areas of a board. Wood knots and wood grain variations provide small visible differences in the wood surface, which may have dramatic effects on insert angles and cutting speeds. Additionally, these wood grain differences vary widely between species of wood. The hook, shear, and back clearance angles are chosen according to the hardness, density and grain variation of the material to be cut. Typically, cutters for metals use negative hook angles. Hard woods, such as hard maple, may also use negative hook angles.
The hook angle B and the shear angle C work together so that only a single point along the insert
22
is actually cutting at any given time. By advancing a board tangentially to the rotating cutterhead
10
, the insert
22
contacts the workpiece at a single point, which moves along the profile of the insert
22
as the cutterhead
10
proceeds through its rotation. The shear angle C causes the bottom of the insert
22
to contact the workpiece first.
The notch
20
within the insert pocket
18
on the cutterhead
10
extends from the supply face
42
to the reference face
56
along the trailing wall
34
. The notch
20
corresponds with a groove (not shown) on the insert
22
. The notch
20
is sized to fit the groove. The notch
20
mates with the groove to ensure a proper insertion of the blade into the pocket
18
of the cutterhead
10
.
As shown in
FIG. 2
, the cutterhead
10
has a supply face
42
and a reference face
56
. The access face
36
exposes the leading face
46
of the insert
22
when the cutterhead
10
is rotated in the direction E. The cutterhead
10
has an insert pocket
18
having a ramp wall
32
and a trailing insert pocket wall
34
, which defines one side wall of the insert pocket
18
. The trailing insert pocket wall
34
provides a support surface for the trailing face
44
of the cutting insert
22
. The ramp edge
50
of the cutting insert
22
contacts the back wall
32
of the insert pocket
18
which extends away from the central axis
15
of the cutterhead
10
as the back wall
32
extends from the supply face
42
to the reference face
56
.
When an insert
22
is inserted into the insert pocket
18
such that the ramp edge
50
contacts the ramp wall
32
, the insert
22
is advanced axially and radially along the ramp wall
32
from the supply face
42
toward the reference face
56
until the reference edge
54
of the cutting insert
22
and the reference face
56
of the cutterhead
10
are aligned. The ramp angle A of the ramp wall
32
causes the insert
22
to advance simultaneously both in the axial and in the radial direction. Then the wedge
24
, the clamps
26
, and the clamping screws
28
are inserted into the insert pocket
18
to hold the insert
22
in place.
As shown in
FIG. 3
, the body
12
of the cutterhead
10
has a ring portion that is generally referred to as a shoulder
14
around the bore
16
. The shoulder
14
is raised slightly above the supply face
42
of the cutterhead
10
. Additionally, the shoulder
14
extends outward from the supply face
42
to the reference face
56
such that the shoulder is raised slightly above the reference face
56
of the cutterhead
10
. The shoulder
14
provides a surface for grinding, if required, to true or level the cutting tool path. In certain instances, it may be necessary to modify the cutting tool
10
to serve a particular function. Since the cutting tool
10
is typically customized for the particular application, parts of the cutting tool
10
may need to be adjusted prior to use by either the end user or the manufacturer. The shoulder
14
provides such a surface.
As shown in
FIG. 3
, the back wall of the insert pocket
18
defines a ramp angle A relative to the central axis
15
of the cutterhead
10
. The insert
22
advances axially from the supply face
42
to the reference face
56
along the ramp wall
32
. The ramp edge
50
of the insert
22
mates with the ramp wall
32
of the cutterhead
10
when the insert
22
is properly inserted into the cutterhead
10
.
As shown in
FIG. 4
the insert
22
has a supply edge
52
, a profile or radial edge
48
, a reference edge
54
, and a ramp edge
50
. The ramp edge
50
mates with the back ramp wall
32
of the insert pocket
18
on the cutterhead
10
. The ramp wall
32
of the cutterhead
10
defines an angle A relative to this central axis
15
of the cutterhead
10
. The insert
22
is advanced axially and radially along the ramp edge
50
(as shown by arrows E) until the reference edge
54
of the insert
22
is aligned with the reference face
56
of the cutterhead
10
.
During use, the profile edge
48
of the profile insert
22
gradually becomes dull, and breaks or small cracks may be found along the profile edge
48
due to wear. In such cases, the insert
22
must be replaced or reprofiled. With respect to extant cutting blades
22
, the most cost effective means is simply replace the insert
22
with an identically dimensioned and profiled commercially available insert
22
. However, profiled insert blades significantly more expensive than standard multi-edge insert blades. It is expensive to discard and replace worn profiled insert blades
22
. It is desirable therefore to regrind and resize the cutting insert
22
for reuse.
In the present invention, the insert
22
is removed, and the profile edge
48
is reprofiled to define a new profile edge
48
. Then, a small portion of material is removed along the reference edge
54
defining a new reference edge
54
. Finally, the reprofiled insert
22
may be inserted into the cutterhead
10
such that the ramp edge
50
of the insert
22
mates with the ramp wall
32
of the cutterhead
10
. By removing material from the reference edge
54
, the profile edge
48
of the blade is shifted perpendicular to the reference edge
54
.
The reprofiled insert
22
is then advanced axially and radially along the ramp edge
50
until the new reference edge
54
is aligned with the reference face
56
of the cutterhead
10
. Similarly, the supply edge
52
descends into the insert pocket
18
. The insert
22
is advanced a distance F, the distance between supply edge
52
and new supply edge
52
′, which equals the amount of material removed from the reference edge
54
of the insert
22
to establish a new reference edge
54
′. The ramp wall
32
forces the new profile edge
48
′ outward radially, causing the sharpened profiled insert
22
to present the same cutting diameter, the same axial dimension and the identical profile as the original profiled insert
22
.
Thus, the profile insert
22
may be reprofiled and reinserted into the cutterhead
10
, aligned along the reference edge
54
′ and fixed into place using the wedge
24
, clamps
26
and clamping screws
28
to provide a sharpened insert
22
having the same cutting diameter, axial location and profile as the original insert
22
. No adjustment of the cutterhead
10
axially or radially is required to maintain the same cutting diameter and cutting profile. Thus, work time and money is saved by reprofiling and reusing these insert blades
22
with the cutterhead
10
of the present invention. By removing material along the reference edge
54
of the insert
22
to provide a new reference edge
54
′, the new reference edge
54
′ may be aligned with the reference face
56
of the cutterhead
10
to account for material removed from the profile edge
48
during the reprofiling process, so that the insert
22
may be reused numerous times.
Prior to the present invention, sharpening of an insert
22
caused considerable down time and material waste as end users would insert the resharpened insert
22
and begin testing and adjusting the cutterhead
10
until the desired cut was achieved. Even after testing and adjustment, the prior art cutting tools
10
could not repeat the original dimensions. Sharpening can be performed by face grinding or by cutting a new profile edge. Cutting a new profile edge can be accomplished by regrinding or by some other means. Typical face grinding to sharpen a dull blade alters the profile so that a workpiece made after the reprofiling are different from those made with the original insert
22
. The same is true if the profile insert is reprofiled and reused in a standard cutting tool
10
.
Generally, sharpening can be achieved in a number of ways. In the preferred embodiment, sharpening is performed by cutting a new profile edge (reprofiling) as opposed to face grinding. Reprofiling a new profile edge can be done by regrinding (such as with a CNC grinder) or by cutting on an EDM (Electrical Discharge Machine), or by some other means.
In the present invention, the sharpened insert
22
may be simply reinserted and used without adjustment of the cutterhead
10
. Thus, material waste is reduced or eliminated, measuring and adjustment time by the end user is eliminated, and the life of a profile insert
22
is extended. Generally, a profile insert
22
may be sharpened until the supply edge
52
of the insert
22
extends beyond the top edge of the clamp
26
that is furthest from the reference edge
54
. While it may be possible to sharpen the insert
22
further, the clamp
26
provides a visual line by which to determine the life of the insert
22
.
In
FIG. 5
, the cutterhead
10
is shown in schematic profile. The angle A of the ramp wall pushes against the ramp edge
50
of the insert
22
such that the sharpened profile
48
of the insert
22
extends further radially as it is advanced axially against the ramp wall
32
.
The rotating cutterhead
10
causes the inserts
22
to thrust into and lift a series of chips from the surface of the workpiece. The depth and width of the marks left on the surface of the workpiece are determined by the diameter of the cutterhead
10
, its rotational speed, and the speed of the workpiece being fed under it. The quality and/or smoothness of the surface of the chips or cuts is determined by the back clearance angle D and the hook angle B of the head. Like all woodworking cutting tools, the design of the present invention can be manufactured with any combination of hooks, shears, and clearance angles to be used in cutting the full range of materials.
The most common problem associated with the hook angle D of a cutterhead
10
is tear out. Certain species of wood like cherry, hard maple, alder, fir, African mahogany, and others have a weak bond between the growth rings in the tree. As the workpiece moves along under the blades
22
in a profile cutter
10
, the structures in the workpiece present themselves in ever-changing orientation to the insert
22
. Tear out occurs when the insert
22
begins its upward motion to exit the workpiece, taking a chip with it. The force of the insert
22
lifting the chip causes the workpiece to fracture along grain lines, tearing below the surface of the furthest point of the blade, leaving a hole with one torn and ragged edge. Deep cuts exacerbate this problem.
Sharpening the blades
22
with a higher back clearance angle D results in a sharper insert
22
, which will sever the chip with less upwards stress on the workpiece and minimize the tear out. However, the sharper the insert
22
the shorter the insert
22
life or durability of the insert
22
. Especially on hard species of wood, a high back clearance angle D may not be an option for an extended run. Slowing down the feed speed of the machine results in a thinner chip, reducing the force of the tip of the insert
22
on the workpiece. Running the cutter head
10
slower; however, may cause the insert
22
to dull faster. Another option is to increase the number of blades
22
in the cutterhead
10
. Increasing the number of blades
22
reduces the size of chips and minimizes the tear out; however, for custom profile work, the cost of the profiled inserts
22
generally makes this option too expensive.
As shown in
FIGS. 1-5
, the insert
22
defines a third angle relative to the central axis
15
of the cutterhead
10
, the shear angle C. The shear angle C causes the insert
22
to be ramped such that the profile edge
48
only contacts the workpiece at a single point at any given moment. The portion of the cutting insert
22
closest to the reference edge
54
of the cutterhead
10
leads the rest of the insert
22
into the cut, beginning each new cut. The shear angle C of the blade guarantees that only one point along the insert
22
will be cutting the workpiece at any given time or instant of use. Thus, the stress on the insert
22
is reduced, thereby extending the life of the insert cutter insert
22
. As the insert blade
22
rotates, the insert blade
22
begins a chip, which extends as the cutterhead
10
rotates until the depth of the cutting profile
48
is reached.
The cutting profile
48
of the cutter insert
22
also defines an angle G relative to the curve of the profile. The amount of material moved from the bottom edge of the cutting insert
22
during regrind is a function of the depth of the profile regrind, the size of the angle G and the back clearance angle D of the insert
22
.
Generally, the design and angles of a cutterhead
10
are determined by the cutterhead
10
velocity, the feed of the workpiece per tooth cut, and the workpiece type. The hook angle B of the cutterhead
10
varies from roughly minus 10 degrees to a positive 35 degree angle relative to the central axis
15
. The hook angle B is defined by extending a line from the central axis
15
of the cutterhead
10
to the profile edge
48
of the profiled insert
22
. The angle between the imaginary line from the central axis
14
to the cutting point and the surface of the cutting insert
22
defines the hook angle B. Hard materials such as hard maple woods and metals typically are cut using a negative hook angle B. Softer woods can be cut with angles that extend almost to a positive 35 degrees. Thus, the hook angle B is largely dependent on the material to be cut.
The ramp angle A along which the ramp wall
32
of the insert pocket
18
varies anywhere from 1 degree to 89 degrees from the central axis
15
. The ramp wall
32
may form either a positive or a negative angle within that range relative to the central axis
15
. The angle A of the ramp wall
32
is largely dependent upon the variation depths of the profile edge
48
of the insert cutter insert
22
. For a largely flat profile cutting insert
22
, the angle will typically be larger. For more deep profile cutting blades
22
, the ramp angle A extends approximately 20 degrees. The angle of the ramp edge
50
allows the reprofiled cutter insert
22
to be advanced axially and radially along the ramp edge
50
so that the new profile edge
48
defined by the regrind process is positioned relative to the cutterhead
10
so as to maintain a constant cutting diameter and cutting profile consistent with the original cutting insert
22
.
The shear angle C is defined by a vertical plane extending from the central axis
15
of the cutterhead
10
to the bottom reference edge
54
of the cutter insert
22
. The angle C of the cutting profile
48
of the cutter insert
22
relative to the vertical plane defines the shear angle C. The shear angle C and the back clearance angle D combine to determine the depth of each individual cut.
The cutter insert
22
generally does not extend beyond the supply face
42
of the cutterhead
10
for safety reasons. With each sharpening of the insert
22
, the insert
22
is advanced along the ramp edge
50
toward the reference face
56
so that the supply edge
52
of the insert
22
descends into the insert pocket
18
below the supply face
42
of the cutterhead
10
. The limit on sharpening of the insert
22
is defined so as to assist an end user in determining when to discard the sharpened insert
22
instead of reprofiling it. Specifically, when the supply edge
52
of the sharpened insert
22
reaches the top edge of the upper clamp
26
, the sharpened insert
22
should not be sharpened further. The top edge of the upper clamp
26
provides a visible marker or visible indicator for determining when to stop attempting to reprofile the insert
22
.
Generally, each workpiece or cutting material has a “velocity sweet spot” which is the optimum rotational speed for cutting the material. Within the range of speeds that define the sweet spot, the cutting insert
22
enjoys its longest cutting life. Additionally, the efficiency of the cutting insert
22
and the cutterhead
10
is maximized.
As previously described, in the prior art, with sharpened insert blades, some or all of the critical cutting diameter, the axial dimension, or the profile shape of the insert blade change during face sharpening or reprofiling. Thus, reuse of the sharpened blade by the end user requires significant user time in manually adjusting the cutterhead relative to the workpiece. In addition, all three original dimensions will not be possible
In the present invention, sharpened insert blades
22
may be reinserted into the cutterhead
10
and advanced axially and radially along the ramp edge
50
until the reference edge
54
of the insert cutter insert
22
is aligned with the reference face
56
of the cutterhead
10
. If the insert cutter insert
22
is aligned with the reference face
56
of the cutterhead
10
, the cutting profile, the diameter and the axial position are identical to the original specification. Thus, the end user can simply insert the sharpened insert blades
22
, advance it along the ramp edge
50
until it is aligned with the reference face
56
, and clamp it into position and begin using it without any manual adjustments or comparisons. In addition, the new or reprofiled insert blades
22
are easy to use and the only tool required to remove and reinsert an insert
22
is a simple hex key. Thus, down time and adjustment time is minimized so that the inherent inefficiencies in manual adjustments of the system are practically eliminated.
The access face
36
need not be straight as shown in FIG.
1
. The access face can be curved or of any shape provided the access face is large enough to provide clearance for chips during cutting. Additionally, the position of the insert
22
relative to the wedge
24
and clamps
26
can be altered. Specifically, the wedge
24
and clamps
26
may be placed on the opposite side of the insert
22
, such that the wedge
24
and clamps
26
trail the insert
22
during the cutting rotation. The wedge
24
should still be placed directly adjacent the insert
22
to provide support. This alternative embodiment is desirable when debris (i.e. chips, sap, glue, and so on) from the cutting material is a problem in and around the wedge
24
, clamps
26
, and clamping screws
28
.
In an alternative embodiment, the notch
20
maybe provided on the wedge
24
, such that the insert
22
mates with the wedge
24
. Thus, the notch/groove relationship may be formed with either the wedge
24
or the insert pocket
18
(as depicted).
The present invention may also be applied to numerous different designs of cutting tools
10
, where the insert
22
may be reprofiled and inserted with a minimum of end user adjustment and maintenance of all critical dimensions.
FIGS. 6-10
present the invention applied to a router bit
60
.
As shown in
FIG. 6
, the router bit
60
has a body
62
with a shank
64
. The router bit
60
uses insert blades
22
like those used in the cutterhead
10
of
FIGS. 1-5
. The difference between the cutting tool
10
with bore of
FIGS. 1-5
and the router bit
60
with shank of
FIGS. 6-10
involves the type of machine in which the cutting tool
10
can be used. Specifically, the cutterhead
10
of
FIGS. 1-5
typically is used on a machine with a shaft or spindle that is extending through the bore. The router bit
60
of
FIGS. 6-10
typically is attached to a machine by inserting the shank into shaft collet (not shown).
As shown in
FIG. 6
, the router bit
60
has a body
62
with a shank
64
. The router bit
60
has a circumferential alignment edge
66
and supply area
68
. The router bit
60
defines insert pockets
70
sized to receive insert cutter blades
22
, a wedge
24
, clamps
26
, and clamping screws
28
. The profiled insert
22
is held in place by the wedge
24
, clamps
26
, and clamping screws
28
similar to the cutterhead
10
of
FIGS. 1-5
.
The ramp wall
32
of the insert pocket
70
extends from the supply area
68
to the reference edge
66
at a ramp angle A of approximately
70
degrees relative to the central axis
15
of the router bit
60
. As with the cutterhead
10
, the ramp wall
32
forces the radial edge
48
of the insert
22
toward the workpiece. The hook angle B is again shown, as is the shear angle C previously described.
The router bit
60
allows the end user to remove, sharpen and reuse the profile insert blades
22
. As with the insert
22
shown in
FIG. 4
, material is removed from the reference edge
54
of the insert
22
, establishing a new reference edge
54
. The insert
22
is then advanced from the supply area
68
along the ramp wall
32
until the new reference edge
54
is aligned with the circumferential reference face
66
of the router bit
60
. Thus, the profile, cutting diameter, and axial dimension of the router bit
60
can be maintained through multiple sharpenings and with no further manual or mechanical adjustment to the cutting tool body.
As shown in
FIG. 7
, the router bit
60
has a wedge
24
, clamps
26
and clamp screws
28
to hold the profile insert
22
in place. The profile insert
22
extends at a hook angle B relative to an axis normal to the central axis
15
. Cutaways
72
provide access to the insert
22
. The cutaways
72
may be curved or straight. As shown, the cutaways
72
intersect the circumferential reference edge
66
of the router bit
60
. A scalloped or cupped cutaway
72
′ extends from the cutaway
72
toward the central axis
15
of the router bit. The scalloped cutaways
72
′ provide additional space for chips and debris to fall way from the cutting edge. In the embodiment shown, a hex screw
76
is employed to align the reference edge
54
of the insert
22
with the reference face
66
of the router bit
60
. The alignment may also be performed with other fastening means or with a removable magnet or other test surface, provided the alignment means does not interfere with the performance of the cutting blade.
As shown in
FIG. 8
, the router bit body
62
has cutaways
72
similar to those shown with respect to FIG.
1
. The cutaways
72
provide proper release of chips or shavings from the workpiece. A trailing wall
78
of the insert pocket
70
reinforces the profiled insert
22
during use. The ramp edge
50
of the insert cutter insert
22
rests against the ramp wall
32
of the insert pocket
70
, and the trailing face of the cutter insert
22
rests against the trailing wall
78
of the insert pocket
70
. The back wall provides support for the insert
22
. The wedge
24
, clamps
26
and clamping screws
28
hold the insert
22
in place so that it does not move during use.
As shown in
FIG. 9
, the ramp angle A allows the reprofiled cutter insert
22
to be advanced from the central axis
15
toward the outer circumferential reference edge
54
after reprofiling in order to maintain a constant cutting profile and cutting diameter and axial position relative to the original insert blade
22
. Thus, between the original insert
22
and the reprofiled insert
22
, there is no difference in cutting diameter, cutting profile, or axial dimensions. Additionally, the end user simply advances the reprofiled insert
22
toward the circumferential reference face
66
until the reference edge
54
is aligned. The user then clamps the insert
22
into place. No additional measurement or adjustment is required by the end user.
As shown in
FIG. 10
, the insert
22
defines a shear angle C relative to the central axis
15
. The shear angle C is determined according to the material to be cut and the board speed and cut depth desired by the end user. Each cutterhead
10
or router bit
60
may be custom built according to the application. Generally, the desired profile determines the ramp angle A of the insert pocket
70
. A flat profile shape requires a smaller ramp angle A than a deeper cutting profile. Simply put, the advancing of the insert
22
along the ramp wall
32
pushes the new profile edge
48
toward the reference edge as the insert
22
is advanced along the ramp edge
50
. A flat cutting profile does not require as much of a ramp angle A to extend the insert
22
outward as a deeper cutting profile requires. In order to prevent the additional unused material from making contact with the workpiece, the ramp angle must allow the profiled insert to recede into the cutterhead
10
or router bit
60
so as to hide or protect the end user and the workpiece from the unused portion of the insert
22
. With each reprofiling, more of the unused portion of the insert
22
is brought into use, and material at the reference edge
54
of the insert
22
is removed so that most of the cutting insert
22
will ultimately be used. As with the cutterhead
10
described with respect to
FIGS. 1-5
, the insert blades
22
for the router bit
60
shown in
FIG. 10
may be reused until the supply edge
52
of the reference insert
22
reaches the edge of the first clamp
26
.
While the insert
22
may be advanced further than the edge of the first clamp
26
, the edge of the clamp
26
provides a visible means by which to measure the expiration of a reusable insert
22
. Advancing beyond that point exposes the insert
22
and the wedge
24
/clamp
26
assembly to risk because it reduces the amount of force holding the insert
22
in position.
Reprofiling (or sharpening) the inserts
22
as shown in the present invention combined with the ramp angle A allows the reprofiled insert
22
to duplicate the precise profile, axial and radial dimensions as the original. When reinserted into the cutterhead
10
, the reprofiled insert
22
is simply advanced along the ramp edge
52
until the newly defined reference edge
54
reaches the reference face
56
of the cutterhead
10
or the circumferential reference edge
66
. Once the reprofiled insert
22
is advanced to align with the reference face
56
, the insert
22
is clamped into place and the insert
22
is ready to be used. The resulting profile tool diameter and axial position of the reprofiled insert blades
22
within the cutterhead
10
are identical to the original. No manual or measured adjustments are required, and work can proceed immediately. Thus, downtime and manual adjustment time are minimized.
Profiled inserts
22
are typically more expensive than standard multi-edge indexable type inserts. To date, profiled inserts are designed to be thrown out and replaced with new inserts. The reprofiled/sharpened insert alternative presented here minimizes downtime and allows for multiple uses of the same insert
22
so that the profiled inserts
22
are more cost effective and the whole process of removal, reprofiling, reinsertion and use of the reprofiled cutter blades
22
is made more efficient. Reprofiling may save as much as 50% as compared to a new profiled insert
22
, for the user.
In the preferred embodiment, the trailing wall of the insert pocket
18
is machined with either a ridge or similar locating means
20
extending from the supply face
42
to the reference face
56
of the cutterhead
10
(or the supply area
68
to the circumferential reference edge
66
of the router bit
60
), parallel to the ramp wall
32
. A corresponding groove on the insert
22
is sized to fit the ridge
20
of the insert pocket
18
. The groove on the insert
22
mates with the ridge
20
on the trailing wall face of the insert pocket
18
so as to ensure proper insertion of the insert blade into the cutterhead
10
or router bit
60
. When the wedge
24
, clamps
26
, and clamping screws
28
are in place, the ridge/groove relationship provides additional locking means and support for the insert blade. As previously discussed, in an alternative embodiment, either
20
may be provided on the wedge
24
.
As shown in
FIG. 11
, the amount of material used in the insert
22
may be reduced by providing a stepped ramp
32
in the cutting tool
60
. The insert
22
can then be cut with a corresponding step on its ramp edge
50
. By maintaining a constant depth of the steps on the stepped ramp edge
50
of the insert
22
, the ramp edge
50
is in contact with the stepped ramp
32
and the stepped ramp
32
serves the same purpose as the angled ramp
32
, namely to push the profile cutting edge
48
outward as the resharpened blade is advanced toward the reference face
66
of the router bit
60
. In the cutting tool
10
shown in
FIGS. 1-5
, the stepped ramp
32
may also be used. The stepped ramp
32
permits a smaller body
12
,
62
because the stepped ramp
32
does not need to extend as deeply into the body
12
,
62
as the angled ramp wall
32
. Furthermore, the stepped ramp
32
permits a smaller insert blade. In this embodiment, the wedge (not shown) may also be stepped to mate with the stepped ramp
32
.
The cutaways
72
need not be flat. As shown in
FIG. 11
, the cutaways
72
may be scalloped or curved. The shape and depth of the cutaways
72
in the router bit
60
and the access face
36
of the cutterhead
10
may vary according to the cutting material. Nevertheless, the access face
36
or cutaways
72
allow space for wood chips and debris to fall away from the insert blade
22
during use.
In another embodiment, the insert is comprised of a structure where the cutting material is secured to another material, forming a carrier or insert body having an attached cutting tip. This is commonly used with brittle cutting material such as mono or poly-crystalline diamond.
In the present invention, the reprofiled blades
22
have the same axial dimensions, the same cutting diameter, and the identical profile as the original insert blade, with an error margin of less than 1.5 mils. Each profile insert
22
may be reprofiled multiple times, and the same insert
22
maybe resharpened and reused until the supply edge
52
of the insert
22
reaches the top of the clamp
26
.
The insert blades
22
of the present invention generally are in the range of 2 mm to 2.5 mm thick. However, the invention will work with polycrystalline diamond-edged blades up to 0.2 inches thick. Such diamond edged blades may be used for extremely hard woods and for man-made materials, such as high glue, high abrasive materials.
In the preferred embodiment, flat surfaced magnets are used to assist the end user to properly align the new or reground insert
22
with the reference face
56
of the cutterhead
10
. The magnet is placed on the reference face
56
over the insert pocket
18
. As the reground insert
22
is advanced along the ramp wall
32
, the new reference edge
54
′ of the insert
22
approaches the magnet until the insert
22
touches the magnet. The magnet may then be used to hold the insert
22
while the wedge
24
, clamps
26
and clamping screws
28
are tightened into the insert pockets
18
. In another embodiment, the alignment is accomplished with a screw head or other flat surface, such that the means used to assist in aligning the insert blade reference edge
54
′ with the reference face
56
does not interfere with the cutting process.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
Claims
- 1. A method for reusing profile insert blades while maintaining axial, radial and profile dimensions of a cutting tool, the method comprising:duplicating an original profile on a used profile insert blade; sharpening a profile edge of the used profile insert blade to form a sharpened profile edge with a new profile that is shifted longitudinally along a length of the profile cutter blade relative to an original profile position; removing material from a reference edge of the sharpened profile insert blade to form a new reference edge of the sharpened profile insert blade to adjust the new profile longitudinally relative to the original profile position so the new adjusted profile has similar axial, radial and profile dimensions as the original profile; and installing the sharpened profile insert blade onto a rotating profile cutting tool comprising: a tool body releasably attached to a spindle along a central axis, the cutting tool body having a reference face and a supply face, the cutting tool body having insert pockets extending into the cutting tool body, the insert pockets defining a ramp wall having a ramp angle other than zero degrees relative to the central axis; and a clamping mechanism for clamping the sharpened profile insert blade in the insert pocket to prevent movement of the sharpened profile insert blade during use; wherein the sharpened profile insert blade is installed into one of the insert pockets such that a ramp edge contacts the ramp wall and the new reference edge is aligned with the reference face of the cutting tool body.
- 2. The method of claim 1, wherein the cutting tool includes a guide mechanism on the tool body extending parallel to the ramp wall from the supply face to the reference face along a trailing wall face of the insert pocket.
- 3. The method of claim 2, wherein the reusable profiled inserts have an insert guide sized to fit the guide mechanism, the insert guide extending from a supply edge to the reference edge of the reusable inserts, the method further comprising:mating the insert guide with the guide mechanism to ensure proper insertion and safety of the sharpened profile insert blade.
- 4. The method of claim 1, wherein the ramp wall includes one or more threaded bore holes sized to receive a hex clamping screw, the method further comprising:tightening one or more clamps against the ramp wall with the hex clamping screw.
- 5. The method of claim 1, wherein the insert pocket comprises:a trailing wall face; a leading wall face parallel to the trailing wall face; the ramp wall intersecting both the trailing wall face and the leading wall face; and an access face intersecting the leading wall face, the access face for providing chip clearance and for exposing a profile edge of the reusable insert.
- 6. The method of claim 1, wherein the ramp angle is between 1 degree and 89 degrees.
- 7. The method of claim 1, wherein the sharpened profile insert blade is a profile cutting knife having a profile cutting edge.
- 8. The method of claim 7, wherein, after installation, the profile cutting edge of the sharpened profile insert blade defines a monotonically decreasing effective blade radius.
- 9. The method of claim 1, wherein the ramp wall is stepped.
- 10. The method of claim 1, wherein the new adjusted profile has the same axial, radial and profile dimensions as the original profile within a margin of error of 1.5 mils.
- 11. The method of claim 1, wherein after duplicating the original profile on the used profile insert blade, the method further comprising:inserting the profile insert blade into the insert pocket on the cutting tool; aligning the reference edge of the profile insert blade with the reference face of the cutting tool; clamping the profile insert blade into place with the clamping mechanism; and using the profiled insert blade.
- 12. The method of claim 1, the method further comprising:evaluating wear on the profile insert blade; and removing the profile insert blade from the cutting tool for sharpening.
- 13. The method of claim 1, the method further comprising:inserting the sharpened insert blade into the insert pocket on the cutting tool; advancing the sharpened insert blade within the pocket until the new reference edge is aligned with a reference face of the cutting tool; and clamping the sharpened insert blade into position.
- 14. The method of claim 13, wherein the profile insert blades and the sharpened insert blades have a constant effective cutting profile through multiple regrindings.
- 15. The method of claim 1, wherein the profile insert blade has two parallel faces.
- 16. The method of claim 1, wherein the profile insert blade defines a monotonically changing effective blade radius along its length from a supply face to a reference face.
- 17. A method for reusing profile insert blades while maintaining axial, radial and profile dimensions of a cutting tool, the method comprising:duplicating an original profile on a used profile insert blade; sharpening a profile edge of the used profile insert blade to form a sharpened profile edge with a new profile that is shifted longitudinally along a length of the profile cutter blade relative to an original profile position; removing material from a reference edge of the sharpened profile insert blade to form a new reference edge of the sharpened profile insert blade to adjust the new profile longitudinally relative to the original profile position so the new adjusted profile has similar axial, radial and profile dimensions as the original profile; inserting the sharpened insert blade into a pocket on a cutting tool; advancing the sharpened insert blade within the pocket until the new reference edge is aligned with a reference face of the cutting tool, wherein the step of advancing the sharpened insert blade comprises: seating the sharpened insert blade within the pocket on the cutting tool such that a ramp edge of the sharpened insert blade contacts an advancing ramp of the pocket; and sliding the sharpened insert blade along the advancing ramp until the new reference edge of the sharpened blade is coplanar with the reference face of the cutting tool; and clamping the sharpened insert blade into position.
- 18. The method of claim 17, wherein the advancing ramp extends at an increasing effective radius from a supply face to the reference face of the cutting tool, the advancing ramp acting to shift the sharpened profile edge of the cutting blade radially outward along the length of the cutting blade as the cutting blade slides longitudinally toward the reference face.
- 19. A method for reusing profile insert blades while maintaining axial, radial and profile dimensions of a cutting tool, the method comprising:duplicating an original profile on a used profile insert blade; sharpening a profile edge of the used profile insert blade to form a sharpened profile edge with a new profile that is shifted longitudinally along a length of the profile cutter blade relative to an original profile position; removing material from a reference edge of the sharpened profile insert blade to form a new reference edge of the sharpened profile insert blade to adjust the new profile longitudinally relative to the original profile position so the new adjusted profile has similar axial, radial and profile dimensions as the original profile; inserting the sharpened reusable blade into an insert pocket of a cutting tool such that a ramp edge of the sharpened reusable blade abuts a back wall of the insert pocket; advancing the sharpened reusable blade longitudinally within the insert pocket; aligning the new reference edge with a reference face of the cutting tool; and fixing the sharpened reusable blade in the pocket; wherein the sharpened reusable profiled insert blade maintains a cutting diameter, axial location and cutting profile substantially similar to the original profile without further adjustment by an end user.
- 20. The method of claim 19, further comprising:examining a profile edge of the profile insert; reprofiling the profile insert along the profile edge to a depth sufficient to eliminate surface chips and cracks and a dull used edge; and removing material along a reference edge of the profile insert proportional to the depth.
- 21. The method according to claim 20, wherein removing material along the reference edge effectively repositions the profile edge of the reprofiled profile insert to original radial and axial position according to original specifications.
- 22. The method according to claim 20, the method further comprising:reprofiling the profile insert to match the original profile specification; and inserting the reprofiled insert into a cutting tool body to use without adjustment.
- 23. The method according to claim 22, wherein before inserting the reprofiled insert into the cutting tool body, the method further comprising:sharpening a cutting edge of the reprofiled insert.
- 24. A method for reusing profile insert blades while maintaining axial, radial and profile dimensions of a cutting tool, the method comprising:duplicating an original profile of a new profile insert blade on a used profile insert blade; sharpening a profile edge of the used profile insert blade to form a sharpened profile edge with a new profile that is shifted relative to an original profile position; and removing material from a reference edge of the sharpened profile insert blade to form a new reference edge such that the new profile matches axial, radial and profile dimensions of the original profile; inserting the sharpened insert blade into a pocket on a cutting tool; advancing the sharpened insert blade within the pocket until the new reference edge is aligned with a reference face of the cuttings tool, wherein the step of advancing the sharpened insert blade comprises: seating the sharpened insert blade within the pocket on the cutting tool such that a ramp edge of the sharpened insert blade contacts an advancing ramp of the pocket; and sliding the sharpened insert blade along the advancing ramp until the new reference edge of the sharpened blade is coplanar with the reference face of the cutting tool; and clamping the sharpened insert blade into the pocket to secure the new reference edge relative to the reference face.
- 25. The method of claim 24, wherein the new profile has the same axial, radial and profile dimensions as the original profile within a margin of error of 0.0015 inches.
- 26. The method of claim 24, the method further comprising:evaluating wear on the used profile insert blade; and removing the used profile insert blade from the cutting tool for sharpening.
- 27. The method of claim 24, wherein the profile insert blades and the sharpened insert blades have a constant effective cutting profile through multiple regrindings.
- 28. The method of claim 24, further comprising:fastening the sharpened insert blade on a cutting tool; and cutting with the cutting tool without further adjustment.
- 29. The method of claim 24, wherein the advancing ramp extends at an increasing effective radius from a supply face to the reference face of the cutting tool, the advancing ramp acting to shift the sharpened profile edge of the cutting blade radially along the length of the cutting blade as the cutting blade slides toward the reference face.
- 30. A method for reusing profile insert blades while maintaining axial, radial and profile dimensions of a cutting tool, the method comprising:duplicating an original profile of a new profile insert blade on a used profile insert blade; sharpening a profile edge of the used profile insert blade to form a sharpened profile edge with a new profile that is shifted relative to an original profile position; and removing material from a reference edge of the sharpened profile insert blade to form a new reference edge such that the new profile matches axial, radial and profile dimensions of the original profile inserting the sharpened profile insert blade into an insert pocket of a cutting tool such that a ramp edge of the sharpened profile insert blade abuts a back wall of the insert pocket; advancing the sharpened profile insert blade within the insert pocket; aligning the new reference edge with a reference face of the cutting tool; and fixing the sharpened profile insert blade in the pocket; wherein the sharpened profile insert blade maintains a cutting diameter, axial location and cutting profile substantially similar to the original profile without further adjustment by an end user.
- 31. The method of claim 33, wherein the duplicating act comprises:reprofiling the profile insert along the profile edge to a depth sufficient to eliminate surface chips and cracks and a dull used edge; reprofiling the profile insert to match an original profile specification of the profile insert; and removing material along a reference edge of the profile insert proportional to the depth.
- 32. The method for sharpening a profile insert according to claim 31, wherein removing material along the reference edge effectively repositions the profile edge of the reprofiled profile insert to an original radial and axial position according to original specifications for the profile insert.
- 33. The method for sharpening a profile insert according to claim 31, wherein the steps are repeated each time the profile insert becomes dull or has chips or cracks along the profile edge.
- 34. The method for sharpening a profile insert according to claim 31 further comprising:sharpening a cutting edge of the profiled insert.
US Referenced Citations (33)
Foreign Referenced Citations (3)
Number |
Date |
Country |
682 469 |
Sep 1993 |
CH |
31 20 962 |
Dec 1982 |
DE |
41 21 289 |
Jan 1992 |
DE |
Provisional Applications (1)
|
Number |
Date |
Country |
|
60/243186 |
Oct 2000 |
US |