U.S. patent application number 11/775704 was filed with the patent office on 2008-01-17 for anchoring drill bit, system and method of anchoring.
Invention is credited to DONALD S. NADLER.
Application Number | 20080014048 11/775704 |
Document ID | / |
Family ID | 34556529 |
Filed Date | 2008-01-17 |
United States Patent
Application |
20080014048 |
Kind Code |
A1 |
NADLER; DONALD S. |
January 17, 2008 |
ANCHORING DRILL BIT, SYSTEM AND METHOD OF ANCHORING
Abstract
A system, apparatuses and methods for anchoring are provided.
The system includes two-stage drill bit and a method of anchoring
into a two-stage hole drilled by the drill bit. The apparatus of
the instant invention includes a two-stage drill bit for drilling a
pilot hole for a common nail into a material such as concrete,
stone, masonry or cementuous or other materials. The method of the
instant invention includes the steps of drilling a first hole
within a material to which an object is to be anchored, drilling a
second hole concentric with the first hole, and placing an anchor
within the holes.
Inventors: |
NADLER; DONALD S.; (Blue
Springs, MO) |
Correspondence
Address: |
SONNENSCHEIN NATH & ROSENTHAL LLP
P.O. BOX 061080
WACKER DRIVE STATION, SEARS TOWER
CHICAGO
IL
60606-1080
US
|
Family ID: |
34556529 |
Appl. No.: |
11/775704 |
Filed: |
July 10, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10988998 |
Nov 12, 2004 |
|
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11775704 |
Jul 10, 2007 |
|
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60519223 |
Nov 12, 2003 |
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Current U.S.
Class: |
411/387.8 ;
411/439 |
Current CPC
Class: |
Y10T 408/906 20150115;
B23B 2251/54 20130101; B23B 2240/08 20130101; Y10T 408/8925
20150115; B23B 2251/04 20130101; B23B 2251/204 20130101; B23B
2260/0485 20130101; B23B 51/02 20130101; B23B 51/009 20130101; B23B
2251/50 20130101; B23B 49/005 20130101; B23B 2251/14 20130101; B23B
2226/75 20130101; B23B 2270/54 20130101 |
Class at
Publication: |
411/387.8 ;
411/439 |
International
Class: |
F16B 25/10 20060101
F16B025/10 |
Claims
1. A method of anchoring comprising the steps of: cutting a hole
including a first diameter in a material to a first depth; cutting
a hole including a second diameter generally concentric with the
first diameter hole in the material to a second depth; and
positioning a nail shank into the first and the second diameter
holes.
2. The method as claimed in claim 1 further comprising the step of
driving the nail through an object to be anchored to the material
prior to said step of positioning the nail shank.
3. The method as claimed in claim 2 wherein said step of driving
the nail through the object includes the step of inserting the nail
shank through a pre-drilled hole in the object.
4. The method as claimed in claim 3 wherein the pre-drilled hole in
the object is made during said steps of cutting the first and
second diameter holes in the material.
5. The method as claimed in claim 1 wherein the first diameter is
less than the second diameter.
6. The method as claimed in claim 5 wherein the first diameter is
less than or equal to a diameter of the nail shank.
7. The method as claimed in claim 5 wherein the second diameter is
greater than a diameter of the nail shank.
8. The method as claimed in claim 1 wherein the first depth is
greater than or equal to a length of the nail shank.
9. The method as claimed in claim 1 wherein the second depth is
less than the length of the nail shank.
10. The method as claimed in claim 1 wherein said steps of cutting
first and second diameter holes are performed by a single two-stage
drill bit.
11. A method of removably anchoring comprising the steps of:
cutting a hole including a first diameter in a material to a first
depth, the first diameter being generally less than or equal to a
diameter of an anchor; cutting a hole including a second diameter
generally concentric with the first diameter hole in the material
to a second depth, the second diameter being generally greater than
the diameter of the anchor; positioning an anchor into the first
and the second diameter holes such that the anchor is in frictional
engagement with the material at a circumference of the first
diameter hole; and removing the anchor from the first and second
diameter holes when the anchor is no longer needed.
Description
[0001] This application is a divisional of U.S. application Ser.
No. 10/988,998 filed Nov. 12, 2004, which claims priority pursuant
to 35 U.S.C. 119(e) to co-pending U.S. Provisional Patent
Application Ser. No. 60/519,223, filed Nov. 12, 2003, the entire
disclosures of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to systems,
apparatuses and methods for anchoring. More particularly, the
present invention is concerned with a two-stage drill bit and a
method for anchoring into brittle materials such as concrete,
stone, masonry and cementuous materials using a common nail.
BACKGROUND OF THE INVENTION
[0003] In construction applications it is often necessary or
desirable to anchor into an existing concrete structure. In many
construction applications the anchor is intended to be permanent to
tie in a newer structure with an existing concrete structure. In
such permanent anchoring applications, removal of the anchors is
generally not a concern. Thus, the removal of such permanent
anchors from the concrete will undoubtedly result in damage to the
surface of the concrete.
[0004] A number of construction applications currently exist in
which it is desirable to provide an anchor into an existing
concrete structure that is removable. An example of such an
application is present in the commercial construction business in
which concrete tilt-wall construction is often employed. In a
tilt-wall construction, forms are usually anchored into an existing
concrete floor in the shape of the wall. A release agent is applied
to the floor and the forms and concrete mix is poured into the
forms. When the concrete has hardened, the forms are removed and
the wall is lifted from the floor and positioned upright using a
crane.
[0005] A number of "removable" anchoring systems currently exist
for use with concrete. The most common of such systems include
either a nail or screw, both of which require pre-drilling of a
pilot hole. When a standard nail, such as an 8 common, 8 duplex, 16
common, 16 duplex or the like, is utilized, the pilot hole is
usually drilled to be a diameter slightly smaller than the diameter
of the nail so as to provide a tight frictional fit between the
nail and the concrete when the nail is driven into the hole. A
common problem with such applications is that the surface of the
concrete is usually damaged as the nail is removed from the
concrete.
[0006] The most common type of damage to the surface of the
concrete is known as spawling, which is caused when the surface of
the concrete surrounding the pilot hole is pulled upward by
friction with the nail as the nail is pulled upward and breaks away
leaving an indentation or pit in the surface of the concrete. When
the diameter of the pilot hole is slightly smaller than the
diameter of the nail, spawling usually occurs around the entire
circumference of the pilot hole. Spawling in a concrete surface is
undesirable as it creates an unattractive surface and patching a
spawled surface is difficult as the patch will usually flake
off.
[0007] In an attempt to reduce or eliminate spawling, many
contractors will drill a pilot hole having a diameter slightly
larger than the diameter of the nail that is being utilized.
Because the diameter of the hole is larger than the nail diameter,
it is then necessary to insert a softer (than the nail and the
concrete) material, such as lawn trimmer cord or a wire, into the
hole to provide the frictional fit between the nail and the
concrete. Insertion of the softer material is extremely time
consuming and requires that the contractor have an ample supply of
the material on hand. Furthermore, spawling often still occurs when
the nail is removed, as the softer material is usually located on
one side of the nail and the opposite side is pressed up against
the concrete. When the nail is removed, spawling occurs on the side
of the concrete which the nail is pressed against. In some
instances contractors will use a specially designed nail that
includes a section of the nail shank near the end of the nail that
protrudes outward. The outward protrusion provides frictional
contact between the nail and the wall of the pilot hole and
functions in much the same manner as the softer material described
above. Such specially designed nails are extremely expensive when
compared to standard nails, and also result in the same one-sided
spawling discussed above.
[0008] As an alternative to nails, many contractors now use a screw
anchor when a removable anchor is desired. An example of a screw
anchoring system is currently marketed by "Tapcon". This system
includes a drill bit, a hex (or Phillips) driver and sleeve, and a
screw. In operation a contractor will drill a pilot hole with a
drill bit that is smaller than the diameter of the screw. The
contractor then slides the sleeve over the drill bit so that the
hex driver is powered by the drill. The contractor then uses the
driver to drive the screw into the pilot hole. When it is desired
to remove the screw the contractor reverses the driver. While this
system does reduce spawling to the concrete surface when the screw
can be reversed out of the pilot hole, some spawling often does
still occur when the screw is reversed, and a number of other
disadvantages exist. Screws are relatively expensive (approx. $0.18
each) when compared to the cost of standard nails (less than. $0.01
each). The wear on the contractor's drill is significant as it is
used not only to drill the pilot hole, which necessitates very
little torque, but also to drive and reverse the screw, which
necessitates considerable torque. The time requirement of driving
and reversing the screws is significant. In addition, the heads of
the screws often strip out, making reversal of the screws
impossible and resulting in substantial spawling to the concrete
surface when the screw must be forcefully extracted from the
concrete. Therefore, it would be beneficial to provide a low cost
concrete anchoring system that can be removed without resulting in
spawling to the surface of the concrete.
SUMMARY OF THE INVENTION
[0009] An object of the instant invention is to provide a system,
apparatuses and methods for anchoring, particularly into materials
that are relatively brittle under tension, such as concrete, stone,
masonry and cementuous materials. Another object of the instant
invention is to provide a system, apparatuses and methods for
anchoring that are low cost. Another object of the instant
invention is to provide a system, apparatuses and methods for
anchoring, particularly into concrete and other "brittle"
materials, which can be removed without causing spawling to the
surface.
[0010] The objects of the instant invention are accomplished
through the use of a two stage masonry drill bit. The drill bit
includes two masonry cutting surfaces/stages having two different
cutting diameters. The first cutting surface is located at the
outer end of the drill bit and has a first diameter. The second
cutting surface is located along the shank of the drill bit a
distance away from the end and has a second diameter that is larger
than the first diameter. In operation, the drill bit is inserted
into a drill and the end of the bit is pressed against the surface
of the material that is to be drilled (e.g. a concrete floor). The
first cutting surface will cut a hole having a first diameter. As
the bit cuts into the material the second cutting surface will
advance and ultimately widen a portion of the hole to a second
diameter. When the bit is removed, a hole is left in the material
having two concentric diameters. A first, narrower diameter will
extend into the material to a depth in which the end of the drill
bit was driven. The second, larger diameter will extend from the
surface down to a depth in which the second cutting surface was
driven.
[0011] In a preferred embodiment of the instant invention, a depth
gage is located on the shank of the drill bit a distance away from
the second cutting surface in a direction opposite the first
cutting surface. The depth gage can fixed or
repositionable/adjustable. In one embodiment the depth gage is a
member that protrudes from the shank of the drill bit to prevent
the bit from advancing into the hole once the gage contacts the
surface of the material that is being drilled.
[0012] The preferred embodiment of the anchoring system and methods
of the instant invention utilize the two stage bit discussed above.
In the method of the instant invention, the object that is to be
anchored, such as a wooden form, reveal or the like, is placed on a
concrete surface. A first hole is then drilled through the form and
into the concrete to a first depth. A second hole of a diameter
larger than the diameter of the first hole, and having the same
center point as the first hole, is drilled to a second depth that
is less than the first depth (although the terms first and second
are used to describe the holes of the instant invention, it will be
appreciated that the order of drilling the holes of the instant
invention can be reversed without departing from the scope of the
invention; however it is appreciated that by drilling the narrower
hole first, the wider hole can be automatically centered). A
standard nail is then driven through the hole in the form that is
being anchored and into the hole in the concrete. The diameter of
the first hole is slightly smaller than, equal to, or slightly
larger than, the diameter of the nail shank so as to provide a
desired frictional fit between the nail and the concrete. The
diameter of the second hole is larger than the diameter of the nail
shank, such that relief is provided between the surface of the nail
shank and the circumference of the second hole at the concrete
surface. The diameter of the second hole is less than the diameter
of the head of the nail so as to prevent the nail head from being
driven into the hole drilled in the form. The depth of the second
hole can be varied to provide the desired amount of frictional
force to the nail when located in the hole. Increasing the depth of
the second hole increases the size of the relief, reducing the
frictional force on the nail. Alternatively, decreasing the depth
of the second hole decreases the size of the relief, increasing the
frictional force on the nail. When the form is desired to be
removed the nail is removed with a hammer or a crow bar. Because
the shank of the nail never contacts the circumference of the
second hole, which extends to the surface of the concrete, no
spawling will occur. The holes can easily be filled with concrete
patch. In some instances, the clean edges of the holes do not even
need to be patched, as the clean edges do not result in an
unattractive surface.
[0013] The instant invention results in a significant time savings
over the anchoring systems of the prior art. In the instant
invention, all that is required to install and anchor is the
drilling of a two-stage pilot hole and driving a standard nail into
the hole. This results in substantial time savings over prior art
systems that require insertion of a separate softer material into
the hole and over systems that require an anchor be screwed into
the concrete. The removal, or tear down, or anchors of the instant
invention, which requires only the use of a crow bar, provides
significant time savings over removal of the screw anchors of the
prior art, and eliminates spawling caused sometimes by screw
anchors and almost always by nail anchor systems of the prior art.
In addition to the significant time savings for both installation
and tear down of the anchors, the instant invention also results in
a substantial cost savings and convenience. The instant invention
utilizes standard nails that are already purchased in bulk at low
cost by most contractors. The contractors do not need to purchase
any special tools, other than the inventive drill bit, to install
and remove the anchors; instead the contractor merely uses a common
hammer and/or crow bar. In addition, the life of the contractor's
drill will be increased significantly as it is not being used for
high torque driving and reversing of screws.
[0014] The foregoing and other objects are intended to be
illustrative of the invention and are not meant in a limiting
sense. Many possible embodiments of the invention may be made and
will be readily evident upon a study of the following specification
and accompanying drawings comprising a part thereof. Various
features and subcombinations of invention may be employed without
reference to other features and subcombinations. Other objects and
advantages of this invention will become apparent from the
following description taken in connection with the accompanying
drawings, wherein is set forth by way of illustration and example,
an embodiment of this invention and various features thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] A preferred embodiment of the invention, illustrative of the
best mode in which the applicant has contemplated applying the
principles, is set forth in the following description and is shown
in the drawings and is particularly and distinctly pointed out and
set forth in the appended claims.
[0016] FIG. 1 is a front sectional view of an embodiment of a
two-stage drill bit of the instant invention.
[0017] FIG. 2 is a front sectional view of an alternate embodiment
of a two-stage drill bit of the instant invention.
[0018] FIG. 3 is a front sectional view of a nail anchoring a
two-by-four form to a concrete surface through use of the method of
the instant invention.
[0019] FIG. 4 shows a front sectional view of an alternate
embodiment of a nail anchoring a two-by-four form to a concrete
surface through use of the method of the instant invention.
[0020] FIGS. 5a, 5b, 5c, 5c(i), 5c(ii), 5d, 5d(i) and 5d(ii) show
various views of another alternative embodiment of a two-stage
drill bit and corresponding cutters of the instant invention.
[0021] FIGS. 6a, 6b, 6c, 6c(i), 6c(ii), 6d and 6d(i) show various
views of another alternative embodiment of a two-stage drill bit
and corresponding cutters of the instant invention
[0022] FIGS. 7a, 7b, 7c, 7c(i), 7c(ii), 7d, 7d(i) and 7d(ii) show
various views of another alternative embodiment of a two-stage
drill bit and corresponding cutters of the instant invention.
[0023] FIGS. 8a, 8b, 8b(i), 8c and 8c(i) show various views of
another alternative embodiment of a two-stage drill bit and
corresponding cutters of the instant invention.
[0024] FIG. 9 shows a top sectional view of an embodiment of a
second stage cutter for a two-stage drill bit of the instant
invention.
[0025] FIG. 10 shows a top sectional view of another embodiment of
a second stage cutter for a two-stage drill bit of the instant
invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0026] As required, a detailed embodiment of the present inventions
is disclosed herein; however, it is to be understood that the
disclosed embodiment is merely exemplary of the principles of the
invention, which may be embodied in various forms. Therefore,
specific structural and functional details disclosed herein are not
to be interpreted as limiting, but merely as a basis for the claims
and as a representative basis for teaching one skilled in the art
to variously employ the present invention in virtually any
appropriately detailed structure.
[0027] Referring to FIG. 1 a front sectional view of one embodiment
of a two-stage drill bit of the instant invention is shown in which
drill bit 10 includes shank/shaft 20, first stage cutter 30 on
shaft 20, second stage cutter 40 on shaft 20 spaced apart from
first stage cutter 30, and depth gage 50 on shaft 20 spaced apart
from second stage cutter 40 in a direction opposite first stage
cutter 30. As is shown in FIG. 1, first stage cutter 30 has a first
cutting diameter that is less than the second cutting diameter of
second stage cutter 30. In the embodiment of drill bit 10 shown in
FIG. 1, shaft 20 increases in diameter at second stage cutter 30
such that flutes 62 have a larger diameter than flutes 60. FIG. 2
shows a front sectional view of an alternative embodiment of a
two-stage drill bit of the instant invention in which shaft 20 of
drill bit 10 has a single diameter over the entire length of drill
bit 10. As is shown in FIG. 2, second stage cutter 40 protrudes
from shaft 20, and flutes 62 and 64 have identical diameters.
[0028] FIGS. 3 and 4 show several front sectional views of a nail
anchoring a two-by-four form to a concrete surface through use of
the method of the instant invention. As is shown in FIGS. 3 and 4,
first stage hole 130 is drilled in a material (such as a concrete
slab 100) to a first depth. Second stage hole 140 is then drilled
to a second depth which is less than the depth of the first stage
hole. Second stage hole 140 is drilled concentric with first stage
hole 130 such that nail 110 will not contact any of the material
surrounding the circumference of second stage hole 140 when nail
110 is positioned in first stage hole 130. The diameter of first
hole 130 is slightly smaller than the diameter of the shank of nail
110 so as to provide a desired frictional fit between the nail and
the concrete. The diameter of the second hole 140 is larger than
the diameter of the shank of nail 110, such that relief is provided
between the surface of the nail shank and the circumference of the
second hole at the concrete surface.
[0029] In FIG. 3 the diameter of second hole 140 is larger than the
diameter of nail head 112 such that nail head could be driven into
second hole 140 if no additional stop is provided. In the
embodiment shown in FIG. 3, nail 110 is either driven through form
120 without cutting a pilot hole, or a pilot hole is drilled
through form 120 with a different drill bit than that which is use
to drill second hole 140. When the instant invention is used for
anchoring objects such as wooden forms to a material, it is common
to use multiple anchors on a single object. As such, it is
cumbersome to first drill holes into the material to which the
object is going to be mounted, and then drill a hole through the
object to be mounted. Also, it is difficult to line up a nail on
the surface of the object (i.e. a 2.times.4 form) and drive the
nail through that object and into a hole on the opposite side of
the object. Thus, it is preferred to drill a hole through the
object and through the material to which the object is being
anchored all at the same time. Therefore, as is shown in FIG. 4, in
a preferred embodiment of the instant invention, the diameter of
second hole 140 is less than the diameter of head 112 of nail 110
so as to prevent the nail head from being driven into a hole
drilled in the form at the same time as drilling second and/or
first holes 130 and 140.
[0030] The depth of second hole 140 in FIGS. 3 and 4 can be varied
to provide the desired amount of frictional force to the surface of
nail 110 when located in first hole 130. Increasing the depth of
second hole 140 increases the size of the relief, reducing the
length of nail 110 that can be driven into first hole 130 and thus
decreasing the frictional force on the surface of nail 110.
Alternatively, decreasing the depth of second hole 140 decreases
the size of the relief, increasing the length of nail 110 that can
be driven into first hole 130 and thus increasing the frictional
force on the surface of nail 110.
[0031] In the instant invention, when form 120 is desired to be
removed nail 110 is removed with a hammer or a crow bar. Because
the shank of nail 110 never contacts the circumference of second
hole 140, which extends to the surface of concrete 100, no spawling
will occur. The holes can easily be filled with concrete patch. In
some instances, the clean edges of the holes do not even need to be
patched, as the clean edges do not result in an unattractive
surface.
[0032] The depth of first stage hole 130 is sufficient to at least
allow the tip of nail 110 to be driven through two-by-four form 120
and through first stage hole 130 without bottoming out in concrete
100. The depth of second stage hole 140 is sufficient to allow nail
110 to be positioned in the hole and removed from the hole without
resulting in spawling around the surface of the hole as the nail is
removed, yet less than the length of the shaft of nail 110 so as to
allow nail 110 to penetrate into first stage hole 130. The depth of
second stage hole 140 in concrete 100 can be increased or decreased
respectively to decrease or increase the frictional force between
nail 110 and concrete 100.
[0033] It will be appreciated that the two-stage drill bit, 10,
described above with respect to FIGS. 1 and 2, as well as those
described below with respect to FIGS. 5-10, are ideal for use in
the method of the instant invention. Nevertheless, it will be
appreciated that multiple one-stage drill bits could be used
without departing from the spirit or scope of the inventive method.
Furthermore, it will be appreciated that the order of drilling the
holes of the instant invention can be reversed without departing
from the scope of the invention. Nevertheless, drilling the
narrower, deeper hole first (first stage hole 130) provides the
distinct advantage of automatically centering the wider, shallower
hole (second stage hole 140).
[0034] In a preferred embodiment of two-stage drill bit 10 of the
instant invention intended for use with a 16 duplex nail, first
stage cutter 30 includes a cutting diameter of 0.156 inches to cut
first stage hole 130 to a diameter 0.156 inches, and second stage
cutter 40 includes a cutting diameter of 0.170 inches to cut second
stage hole 140 to a diameter 0.170 inches. As the shank diameter of
a 16 duplex nail is approximately 0.166 inches in diameter, nail
110 will be frictionally held in contact with concrete 100 at first
stage hole 140 and will not contact concrete 100 at second stage
hole 140. Shaft 20 of this embodiment has a length of approximately
five inches. The length between the tip of first stage cutter 30
and second stage cutter 40 is approximately 1 and 3/8 inches, and
the length between the tip of second stage cutter 40 and depth gage
50 is approximately 2 and 3/8 inches. This leaves approximately 1
and 1/4 inches at the top of shaft 20 for a drill chuck to grasp
the shaft without interfering with depth gage 50. In addition, the
length between first stage cutter 30 and depth gage 50 provides a
total cutting depth of 3 and 3/4 inches, which allows an additional
3/4 of clearance at the bottom of first stage hole 130 to allow a
common nail, which will have a longer penetration length than a
duplex nail (approximately 3 inch penetration depth from head to
tip for 16 duplex), to be used without requiring any depth
adjustment.
[0035] FIGS. 5-7 show various views of embodiments of a two-stage
drill bit in which second stage cutter 40 is positioned within slot
22 that is machined through shaft 20 of drill bit 10. In each of
FIGS. 5-7 like figure references (i.e. 5a, 6a, etc.) are intended
to refer to corresponding views of each embodiment. FIGS. 5a, 6a,
and 7a show front views of drill bit 10 looking at the surface of
second stage cutter 40 and showing groove 24 for first stage cutter
30. FIGS. 5b, 6b, and 7b show front views of drill bit 10 rotated
90 degrees from the orientation of FIGS. 5a, 6a and 7a to show slot
22 for second stage cutter 40 and looking at the surface of first
stage cutter 30. Slot 22 and groove 24 are both machined into drill
bit shaft 20, and cutters 30 and 40 are positioned respectively in
groove 24 and slot 22 and brazed or welded to shaft 20. In a
preferred embodiment of the invention intended for use with a 16
duplex or 16 common nail, depth gage 50 is a 3/64 inch thick washer
having an outer diameter of 3/8 inch and an inner diameter of 0.135
inches that is brazed or welded to shaft 20 which has an outer
diameter of 0.135 inches.
[0036] FIGS. 5c, 6c and 7c show the surface of an embodiment of
cutter 30 of the instant invention, which is similar to cutters of
prior art drill bits having a tapered cutting edge. FIGS. 5c(i),
6c(i) and 7c(i) show plan views of the tip of cutter 30 of FIGS.
5c, 6c and 7c. FIGS. 5c(ii), 6c(ii) and 7c(ii) show elevation views
of the side of cutter 30 of FIGS. 5c, 6c and 7c. In a preferred
embodiment cutter 30 has a height and width of 0.156 inches each.
Cutter 30 tapers down from center tip 32 at an angle of 30 degrees
and includes oppositely tapered cutting edges 34 and 36. FIGS. 5d,
6d and 7d show the surfaces of various embodiments of second stage
cutters 40 of the instant invention. In FIG. 5d, cutter 40 includes
two partially tapered edges or angled corners 42 and 44 which
include oppositely tapered cutting faces 48 and 46 respectively
(shown in FIGS. 5d(i) and 5d(ii)). In FIG. 6d, cutter 40 includes
two partially tapered edges or angled corners 42 and 44 which
include non-tapered cutting faces 48 and 46 respectively (shown in
FIGS. 6d(i) and 6d(ii)). In FIG. 7d, cutter 40 includes two edges
42 and 44 tapering down from a center point in the same manner as
described with cutter 30 of FIGS. 5 through 7.
[0037] FIGS. 8a, 8b, 8b(i), 8c and 8c(i) show various views of an
embodiment of a two-stage drill bit of the instant invention in
which second stage cutter 40 is attached as two wings to shaft 20
of drill bit 10, and in which no fluting is included on shaft 20.
FIG. 8a shows a front elevation view of drill bit 10 showing the
surfaces of cutters 30 and 40. FIGS. 8b(i) and 8b(ii) show top and
front views of cutter 30 respectively. As is shown in FIGS. 8b(i)
and 8b(ii) cutter 30 is generally triangular in shape and includes
double tapering faces 32 and 34. Cutter 40 is made up of two
separate wings that are brazed or welded to shaft 20. FIGS. 8c(i)
and 8c(ii) show top and front views respectively of one of the
wings of cutter 40. Each wing of cutter 40 includes a tapered front
tip 41 and two tapered top faces 42 and 44.
[0038] FIG. 9 shows a top sectional view of an embodiment of second
stage cutter 40 for a two-stage drill bit of the instant invention
that includes two separate wings as described above with FIG. 8. As
is shown in FIG. 9, each of the wings is positioned within a slot
or groove, 22 that is machined partway into shaft 20 so that the
wings of cutter 40 each protrude generally radially from shaft 20.
FIG. 10 shows an alternative embodiment in which each of the wings
of cutter 40 protrude in a direction generally tangent to shaft 20.
The embodiment shown in FIG. 10 requires less penetration of slot
22 into shaft 20, resulting in increased strength in shaft 20 over
the embodiment shown in FIG. 9.
[0039] In the preferred embodiments of the inventive drill bit 10
shown in FIGS. 5-8, depth gage 50 is an annular ring or washer that
is permanently brazed or welded to shaft 20. Nevertheless,
alternative embodiments of depth gage 50 can be adjustably attached
to shaft 20 to allow a single bit to be used for nails of a variety
of lengths, or to allow the user to increase or decrease the depth
of second stage hole 140 to achieve a desired frictional force or
for a variety of materials in which friction levels may vary. In
addition, an adjustable depth gage will allow a wider variety of
objects, such as forms, reveal, etc. to be anchored by a single
drill bit, as such various objects will come in a variety of
thickness. In one embodiment, an adjustable depth gage is an
annular ring that includes a set screw to hold the gage to the
shaft of the drill bit. In alternative embodiments, the depth gage
is a part of the holder for the drill bit, such as a drill chuck or
an intermediate component between the chuck and the bit. In one
such embodiment, the drill bit includes left handed male threads
that thread into left handed female threads of the holder.
[0040] In a preferred embodiment of the instant invention the two
stage drill bit is a masonry drill bit in which first stage cutter
30 and second stage cutter 40 are both designed for cutting
materials such as concrete, stone, masonry and cementuous
materials. The instant invention is ideal for use with such
"brittle" (under tension) materials, which will normally spawl at
their surface when prior art anchors are removed. Nevertheless, it
will be appreciated that the drill bit of the instant invention, as
well as the method of anchoring of the instant invention, can be
used with any material in which anchoring is desired, and is
therefore not limited to masonry drill bits and cutters.
Furthermore, although the instant invention has been discussed in
connection with anchoring to generally horizontal materials, it
will be appreciated that anchoring to materials at any orientation,
whether horizontal, vertical or otherwise, can be accomplished
without departing from the spirit and scope of the invention. In
addition, although the method of the preferred embodiment is
discussed in connection with an anchor that is a nail having a
generally continuous shank diameter, other anchors, such as screws,
may be employed without departing from the scope of the
invention.
[0041] It will be appreciated that any of the embodiments of drill
bit 10 disclosed herein can utilize any combination of components
from other embodiments. For example the embodiment of drill bit 10
and corresponding cutter arrangement disclosed in FIG. 8 of the
instant invention could include fluting as disclosed in FIGS. 1-2
and 5-7. Furthermore, the specific type of fluting can be varied
without departing from the instant invention. As further example,
the cutting edge for second cutter 40 shown in any of FIGS. 5-7 can
be used in connection with the wing-style second cutters 40
disclosed in FIGS. 8-10.
[0042] In a preferred embodiment, the drill bit shaft 20 of the
instant invention is made of high speed steel, grade M2 or
equivalent, and the cutters 30 and 40 are made of tungsten-carbide,
grade M10 or equivalent and are bonded or brazed to shaft 20.
Nevertheless, the drill bit/cutters of the instant invention can be
made of any material and manufactured in any manner now known for
drill bits or hereafter discovered, and can be percussion,
non-percussion, diamond impregnated, or another other type of
bit.
[0043] In the foregoing description, certain terms have been used
for brevity, clearness and understanding; but no unnecessary
limitations are to be implied therefrom beyond the requirements of
the prior art, because such terms are used for descriptive purposes
and are intended to be broadly construed. Moreover, the description
and illustration of the inventions is by way of example, and the
scope of the inventions is not limited to the exact details shown
or described.
[0044] Although the foregoing detailed description of the present
invention has been described by reference to an exemplary
embodiment, and the best mode contemplated for carrying out the
present invention has been shown and described, it will be
understood that certain changes, modification or variations may be
made in embodying the above invention, and in the construction
thereof, other than those specifically set forth herein, may be
achieved by those skilled in the art without departing from the
spirit and scope of the invention, and that such changes,
modification or variations are to be considered as being within the
overall scope of the present invention. Therefore, it is
contemplated to cover the present invention and any and all
changes, modifications, variations, or equivalents that fall with
in the true spirit and scope of the underlying principles disclosed
and claimed herein. Consequently, the scope of the present
invention is intended to be limited only by the attached claims,
all matter contained in the above description and shown in the
accompanying drawings shall be interpreted as illustrative and not
in a limiting sense.
[0045] Having now described the features, discoveries and
principles of the invention, the manner in which the invention is
constructed and used, the characteristics of the construction, and
advantageous, new and useful results obtained; the new and useful
structures, devices, elements, arrangements, parts and
combinations, are set forth in the appended claims.
[0046] It is also to be understood that the following claims are
intended to cover all of the generic and specific features of the
invention herein described, and all statements of the scope of the
invention which, as a matter of language, might be said to fall
therebetween.
* * * * *