U.S. patent application number 11/880703 was filed with the patent office on 2008-01-10 for hole saw with replaceable cutting tip.
Invention is credited to Chris Corso, Terry M. Corso.
Application Number | 20080008548 11/880703 |
Document ID | / |
Family ID | 37448433 |
Filed Date | 2008-01-10 |
United States Patent
Application |
20080008548 |
Kind Code |
A1 |
Corso; Chris ; et
al. |
January 10, 2008 |
Hole saw with replaceable cutting tip
Abstract
A device for cutting a hole, such as in sheet metal is provided.
The device includes an axially rotatably cylindrical body that is
operable with a rotatable drive. A distal end portion of the body
includes a replaceable cutting tip and a replaceable pilot. The
cutting tip is secured within a notch in the body and extends
distally from the distal end portion. A shank portion is also
provided which is adapted for securement within a rotational drive
mechanism, such as a hand held drill.
Inventors: |
Corso; Chris; (Bensenville,
IL) ; Corso; Terry M.; (Apple River, IL) |
Correspondence
Address: |
Olson & Cepuritis, LTD.
20 NORTH WACKER DRIVE
36TH FLOOR
CHICAGO
IL
60606
US
|
Family ID: |
37448433 |
Appl. No.: |
11/880703 |
Filed: |
July 24, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11131592 |
May 18, 2005 |
7246975 |
|
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11880703 |
Jul 24, 2007 |
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Current U.S.
Class: |
408/213 |
Current CPC
Class: |
Y10T 408/8957 20150115;
B23B 51/0433 20130101; Y10T 408/8973 20150115; Y10T 408/95
20150115; Y10T 408/901 20150115 |
Class at
Publication: |
408/213 |
International
Class: |
B23B 47/00 20060101
B23B047/00 |
Claims
1. A device for cutting a hole in sheet metal, the device
comprising: a rotatable cylindrical body defining a longitudinal
axis, the body having a lead edge portion and an engagement end
portion; the lead edge portion defining an interior recess defining
a frustoconical portion, a notch for directing sheet metal debris
away from the cylindrical body; a pilot drill bit detachably
secured within the interior recess along said axis and extending
from the lead edge portion, said pilot drill bit adapted to align
the cylindrical body; a detachable cutting tip securable with the
notch, a cutting edge of the cutting tip extending distally from
said lead edge portion; and a shank member integral with the body;
the shank member extending axially from the engagement end of the
body, the shank member adapted for engagement with a rotational
drive.
Description
RELATED APPLICATIONS
[0001] The present application is a continuation of patent
application Ser. No. 11/131,592 filed on May 18, 2005, and issued
as U.S. Pat. No. 7,246,975 on Jul. 24, 2007.
TECHNICAL FIELD OF THE INVENTION
[0002] This invention relates to metal cutting tools and more
particularly to a hole saw for cutting holes in material such as
sheet metal using a hand held drill.
BACKGROUND OF THE INVENTION
[0003] Tools for cutting holes in various materials such as sheet
metal generally fall into two types, those which operate by cutting
or removing the entire interior area of a circle and those which
operate by cutting only the circumferential area of a circle
thereby producing an interior circular plug during the cutting
operation. A conventional fluted drill is an example of the former
type of tool. Such tools have the disadvantage of requiring
substantially more cutting activity in order to produce the desired
hole since the entire volume of the material must be cut away to
form the desired hole. Over a certain diameter, it is much more
efficient and generally quicker to utilize a tool which cuts a
circumferential circle for removing the metal as a plug. Such tools
are generally known as trepanning tools. Tools of this type require
substantially less cutting to achieve a desired hole and therefore
provide large diameter holes quickly and with substantially less
energy consumption.
[0004] The use of trepanning tools which cut only the
circumferential area of circles to provide large diameter holes is
known. Such tools generally comprise an elongated tubular cutting
head having cutting blades or tips secured thereto which engage a
work piece to shave or cut portions thereof to define the
circumference of a circle upon rotation of the tool. Accordingly,
as cutting of a work piece is effected, a center plug is produced
which is received in the center area of the elongated tubular
cutting head. Tools of this type have been available for cutting
holes having diameters ranging from approximately less than an inch
to holes having extremely large diameters for example up to 10
inches or more. Such large diameter trepanning tools are generally
associated with lathe type machines which are fixedly mounted for
producing holes in an automated fashion. Generally, such trepanning
tools are therefore rigidly aligned with the material to be cut
which is usually also clamped or fixed to prevent movement. While
such applications are known in the art, there has been a continuing
effort to produce tools suitable for use in a hand held fashion
which will provide a relatively precise and smooth hole in thin
sheet metal for use, for example, in field construction such as by
an electrician in cutting holes in electrical boxes. In addition,
it is desirable to cut holes in other types of sheet metal such as
stainless steel, which is finding more use in home and building
construction.
[0005] Various examples of hole cutting devices that are adapted
for use with a hand held rotational drive mechanism, such as a hand
held drill, exist. One type of hole saw is essentially a
cylindrical tube having a leading edge with serrations or cutting
teeth. Typically, a pilot drill bit that extends from the
cylindrical tube is incorporated to act as a guide for aligning the
hole saw. One problem with this type of hole saw is that the width
of the teeth are more or less limited to the width of the
cylindrical body of the hole saw, which is generally relatively
thin. As a result, the serrations or cutting teeth are prone to
breakage, which requires replacement.
[0006] Another example of a hole saw is found in U.S. Pat. No.
5,049,010, which discloses a hole saw that utilizes a single
carbide tip permanently secured with a rotatable body. While such a
hole saw has performed adequately, a serious drawback with such
design is due to the fact that the only cutting edge, namely the
carbide tip, is permanently secured or bonded to the body of the
hole saw. When the carbide tip is worn, dulled, or broken, the
entire hole saw must be replaced.
[0007] The present invention overcomes the shortcomings of the
prior art and provides an effective device for cutting holes in
metal.
SUMMARY OF THE INVENTION
[0008] The present invention is directed to a hole cutting device
including a cylindrical body that is operable with a rotatable
drive. The body defines an axis about which the body is rotated. A
distal end portion of the body, which is the lead end of the
device, is adapted to engages the material to be cut or drilled.
The distal end portion further includes an interior defining a
recess that extends away or proximally from the distal end of the
body. The distal end portion also includes a notch cut into the
body. Preferably, the notch does not penetrate through the body to
the interior recess.
[0009] A cutting tip is detachably secured with the notch, and a
portion of the cutting tip, such as a cutting edge, extends
distally from the distal end of the body. The cutting tip is
preferably mechanically secured with a socket formed within the
notch in the body. For example, the cutting tip may be secured
within the socket by a locking screw. The cutting tip also
preferably includes a plurality of cutting edges. For example, the
cutting tip is preferably triangular in shape whereby three cutting
edges are defined. As a particular cutting edge becomes worn, the
cutting tip may be disengaged from the body, and re-engaged with a
fresh cutting edge protruding distally from the body.
[0010] Also extending from the distal end of the body is a pilot
member, such as a drill bit. The pilot member is also detachably
secured with the body along the axis and is adapted to align the
cylindrical body with the material to be cut. A shank member
integral with the body extends from a proximal end of the body
along the axis. The shank member is adapted for engagement with a
rotational drive, such as with the chuck of a hand held drill.
[0011] The cylindrical cutter body is substantially the diameter of
the desired hole. The recess preferably includes a frustoconical
portion which tapers inwardly from the cutting end of the cutter
body. The body further preferably includes an axially disposed bore
extending therethrough for inclusion of the pilot member. The pilot
member is preferably secured within the bore by a locking
screw.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In the drawings,
[0013] FIG. 1 is an exploded perspective view of a preferred
embodiment of a hole cutting device according to the present
invention;
[0014] FIG. 2 is a cross sectional view of the hole cutting device
of FIG. 1 taken across line 1-1;
[0015] FIG. 3 is an exploded perspective view of an alternate
preferred embodiment of a hole cutting device according to the
present invention;
[0016] FIG. 4 is a cross sectional view of the hole cutting device
of FIG. 3 taken across line 2-2; and
[0017] FIG. 5 is an exploded perspective view another alternate
preferred embodiment of a hole cutting device according to the
present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
[0018] The invention disclosed herein is susceptible of embodiment
in many different forms. Shown in the drawings and described
hereinbelow in detail are preferred embodiments of the invention.
It is to be understood, however, that the present disclosure is an
exemplification of the principles of the invention and does not
limit the invention to the illustrated embodiments.
[0019] Referring to FIGS. 1-2, a preferred embodiment of the hole
cutting device of the present invention is shown. The hole cutting
device 10 includes a cylindrical body 20 that is operable with a
rotatable drive, such as a hand held drill (not shown). Device 10
is operated by rotating body 20 about an axis 24. Body 20 has a
distal end portion 26, which is the lead end of the device. In
other words, the distal end portion, and in particular, the distal
end 28 of distal end portion 26 is adapted to engage the material
to be cut or drilled. The distal end portion 26 also includes an
interior defining a recess 30 that extends away from the distal end
28 of the body 20. The recess 30 preferably includes a
frustoconical portion 21 which tapers inwardly from the distal end
28 of the cutter body 20.
[0020] The distal end portion 26 also includes a notch 32 cut away
from the body 20. As shown, notch 32 is taken from the body 20, but
does not extend through to recess 30 for the length of the body 20.
The notch 32 provides for materials that are being cut to be
directed away from the device 10. Because the notch 32 does not
penetrate the recess 30 along the length of the body 20, the
structural strength of the body 20 is maintained. The cylindrical
cutter body is substantially the diameter of the desired hole to be
cut.
[0021] A cutting tip 34 is detachably secured with the notch 32. In
this example, a socket 36 that has a profile of substantially the
same shape as the cutting tip 34 and is sized to accommodate the
cutting 34 therein is provided. A threaded hole 38 is also formed
within socket 36 to accept a fastener, such as locking screw 40.
Screw 40 engages cutting tip 34 through hole 41 to secure cutting
tip 34 with notch 32. Cutting tip 34 includes three cutting edges
42, 44, and 46. Cutting edge 42 is shown as being aligned such that
it extends beyond distal end 28. As the distal end portion 26 of
the device 10 engages the material to be drilled, the rotating
cutting edge 42 cuts a hole.
[0022] When, through use, a cutting edge, such as edge 42 is
dulled, the cutting tip 34 may be disengaged from notch 32, and
realigned such that a new cutting edge, such as edge 44, extends
beyond distal end 28. Alternatively, the cutting tip 34 may be
replaced. While the cutting tip 34 is shown as being substantially
triangular in shape, other profiles, such as square, rectangular,
are also suitable. Some variance is also possible with respect to
the size of hole to be cut. In other words, the cutting tip may
extend radially from the body 20, such that a somewhat larger hole
is cut.
[0023] The cutting tip is preferably composed of tungsten carbide
such as industry code number C-10, and is preferably composed of
micro fine grain tungsten cobalt carbide. Examples of suitable
commercially available cutting tips are produced Interstate Tool
Corporation, such as carbide insert part nos. DPMT21505 ICP22 55,
CEHW-1204-AEER ICP222M, and APKT263PDTR ICP555M. Depending on the
hardness or composition of the material to be cut, other suitable
materials are also possible. For example, different cutting tips
may be utilized to cut through ceramic tile, countertops, or the
like.
[0024] A pilot member, such as drill bit 37, is also provided.
Drill bit 37 is disposed within a bore 48 extending through the
cutter body 20. Such a drill bit preferably includes a fluted
section 49 and a pointed end 51. The drill bit 37 is essentially a
standard drill bit utilized for cutting sheet metal. The drill bit
37 extends beyond the cutting tip 34 to allow the drill bit 37 to
align the hole cutter 10 as desired. The pilot is secured in bore
48 by a locking screw 50, which is engageable with a recess 52,
allowing removal of the pilot as necessary, such as due to breakage
or wear. It is further preferred that drill bit 37 is double sided
such that when one end is worn, it may be reversed.
[0025] A shank member 54 integral with the body 20 extends from a
proximal end 56 of the body 20 along the axis 24. The shank member
54 is adapted for engagement with a rotational drive, such as with
the chuck of a hand held drill. Preferably, the shank member 54 is
of a sufficient length such that it may be fully seated within a
chuck of a hand held drill.
[0026] Referring to FIGS. 3 and 4, an alternative embodiment of the
present invention is shown. Device 110 is similar to the previous
embodiment. Device 110 includes a cylindrical body 120 having a
distal end portion 126, and a lead or distal end 128 which is
adapted to engage the material to be cut or drilled. Notch 132 is
formed in the body 120. In this embodiment, notch 132 includes a
rectangular shaped socket 136 to accommodate cutting tip 134. As in
the previous embodiment, cutting tip 134 is detachably secured
within notch 132, and in particular, socket 136, by way of locking
screw 140 which is guided through hole 141 and secured within
threaded hole 138. Cutting tip 134 only includes one cutting edge
142. When through use, the cutting edge 142 is dulled, cutting tip
134 may be disengaged from socket 136, and replaced with a new
cutting tip.
[0027] Also similar to the previous embodiment, device 110 includes
a pilot member, such as drill bit 137 that is disposed within a
bore 148 extending through the cutter body 120. The drill bit 137
is secured in bore 148 by a locking screw 150, which is engageable
by way of threaded recess 152, and thereby allowing removal of the
drill bit 137 as necessary, such as due to breakage or wear.
[0028] Referring to FIG. 5 is another embodiment of an alternative
embodiment of the present invention. Device 210 includes a
cylindrical body 220 having a distal end portion 226, and a lead or
distal end 228. Notch 232 is formed in the body 220. In this
embodiment, notch 232 includes a partial diamond shaped socket 236
to accommodate cutting tip 234. As in the previous embodiments,
cutting tip 234 is detachably secured within notch 232, and in
particular, socket 236, by way of locking screw 240 which is guided
through hole 241 and secured within threaded hole 238. In this
embodiment, cutting edge 242 provides a pointed cutting edge as
opposed to a flat edge. A pilot member, such as drill bit 237, is
also provided. Drill bit 237 is disposed within a bore 248
extending through the cutter body 220. Such a drill bit preferably
includes a fluted section 249 and a pointed end 251, and is secured
in bore 248 by a locking screw 250, which is engageable with a
recess 252.
[0029] The foregoing descriptions are to be taken as illustrative,
but not limiting. Still other variants within the spirit and scope
of the present invention will readily present themselves to those
skilled in the art.
* * * * *