Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02471927 2004-06-30
TITLE: Sander Attachment for a Drill
FIELD OF THE INVENTION
The invention relates generally to drill attachments for use in sanding.
BACKGROUND OF THE INVENTION
There are numerous attachments and bits for use with electric drills. In
addition to drill
bits, electric drills can be used with grinding, cutting and sanding
attachments. Drill bits which
are designed for use as sanders are well known in the market. These sanding
attachments
generally come in two different forms. The first form consists of a circular
pad mounted to a
drill shaft. The drill shaft is inserted into the chuck of the drill and a
circular piece of sandpaper
is attached to the circular pad. The sandpaper is usually attached to the pad
by means of either an
adhesive or by means of a recessed flanged bolt at the center of the pad. When
the drill is
activated, the circular pad spins allowing the user to sand down an item by
applying the
sandpaper covered pad to the item. After extensive use, the grit on the
sandpaper will either wear
away or become clogged and will have to be replaced. This type of sanding
device is very
popular; however, it can only be used on large flat surfaces because of the
size of the circular
pad.
Another common sander attachment for drills consists of a cylindrical abrasive
stone
coaxially attached to a drill shaft. The drill shaft is attached to the chuck
of the drill before use.
When the drill is activated, the cylindrical abrasive stone spins about its
axis and can be used to
sand or grind. This type of sanding attachment is also popular and is suitable
for use in tight
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corners. The abrasive stones come in a variety of different grits, thereby
allowing the user to
change from one abrasive stone to another as required. Once the grit on the
surface of the stone
wears off, the stone must be replaced. Unfortunately, these stones have a
relatively small surface
area, which in turn means that they wear out relatively quickly. An improved
sanding attachment
which is more durable and less expensive than a traditional cylindrical
grinding stone would be
more extensively used in the market.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a sanding bit for
use with an
electric drill. The bit consists of an elongated member having a drill shaft
formed on a first end
of the member and a slot formed on a second end of the member. The slot is
dimensioned and
configured to receive an elongated strip of flexible sandpaper. The sandpaper
strip is wound
around the second end of the member to form a plurality of layers around the
second end of the
member.
With the foregoing in view, and other advantages as will become apparent to
those skilled
in the art to which this invention relates as this specification proceeds, the
invention is herein
described by reference to the accompanying drawings forming a part hereof,
which includes a
description of the preferred typical embodiment of the principles of the
present invention.
DESCRIPTION OF THE DRAWINGS
FIGURE 1, is a perspective view of a sander attachment made in accordance with
the invention.
FIGURE 2. is a top view of a strip of sandpaper for use with the invention.
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FIGURE 3. is a side view of the sander attachment shown in figure 1 in
combination with an
electric drill.
FIGURE 4, is an end view of the sander attachment made in accordance with the
invention.
FIGURE 5. is an end view of the sander attachment with a strip of sandpaper
being attached
thereto.
FIGURE 6. is an end view of the sander attachment with a strip of sandpaper
wound about the
attachment.
FIGURE 7a. is a perspective view of the preferred embodiment of the present
invention.
FIGURE 7b. is a perspective view of another embodiment of the present
invention.
FIGURE 7c. is a perspective view of another embodiment of the present
invention.
In the drawings like characters of reference indicate corresponding parts in
the different
figures.
DETAILED DESCRIPTION OF THE INVENTION
Referring firstly to figures 1, 2 and 3, the sander attachment, shown
generally as item 10
consists of a barrel member 12 coaxially mounted to a drill shaft 14. Shaft 14
is dimensioned
and configured to releasably mount to chuck 16 of electric drill 18. Barrel 12
has slot 20 which
bifurcates the barrel. Slot 20 is dimensioned and configured to receive
elongated sandpaper strip
22. Sandpaper strip 22 is preferably rectangular and has ends 24 and 26 and
has abrasive surface
28. Sandpaper strip 22 is suitably flexible to permit it to be wound around
barrel I2. Slot 20 is
dimensioned and configured to snugly receive end 24 of sandpaper strip 22.
Sandpaper strip 22
is wound around barrel 12 with abrasive side 28 oriented away from the barrel
member. Barrel
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member 12 and drill shaft 14 are preferably made from a strong material such
as steel or brass.
Preferably, drill bit 10 may be made from a single piece of metal such that
barrel 12 and shaft 14
are contiguous.
Referring now to figures 4, 5 and 6, sandpaper strip 22 is wound around barrel
12 in a
S spiral as illustrated in figures 5 and 6. End 24 is first inserted into slot
20 of barrel 12 and then
strip 22 is wound around the barrel in a spiral with abrasive surface 28
oriented on the outside of
the spiral. Preferably, strip 22 is tightly wound around the barrel to form at
least three layers of
sandpaper, namely layers 30, 32 and 34. Of course, the number of layers will
be determined by
the diameter of barrel 12 and the length of strip 22. When the sandpaper is
fully wound onto the
barrel, the finished bit can be attached to the drill's chuck (see figure 3).
In operation, the bit
should be rotated in the direction indicated by arrow 36 in order to ensure
that the sandpaper
remains tightly wound onto the barrel. Since the slot bifurcates barrel 12,
the sandpaper strip can
be positioned such that portion 25 of end 24 extends beyond the slot. The rest
of the strip may be
wound over portion 25 to ensure that the sandpaper is securely retained onto
the barrel.
The present invention has several advantages over the prior art. Firstly,
since the barrel
portion acts as a holder for sandpaper and does not have any abrasive
characteristics itself, the
drill bit can be used for a variety of different sanding and grinding
applications simply by
changing the type of sandpaper wrapped around the barrel. Hence, where the
sander is to be used
to remove a large amount of material, a relatively coarse grade of sandpaper
can be used. Where
the application calls for finer work, a fine grained sandpaper or emery cloth
may be used. Also,
since the bit may be made from a single piece of ordinary steel or brass, the
bit may be made very
inexpensively. Most significantly, since the sandpaper forms a plurality of
layers around the
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barrel, the bit can be used for an extended period of time before having to
change the sandpaper.
As the bit is used, the outermost sandpaper layer is slowly worn away,
exposing a fresh layer of
sandpaper beneath. In the event that a very durable sandpaper is used, the
outermost layers can
simply be removed as they become worn down or clogged up. As the worn layers
are removed,
the underlaying fresh layer is exposed, permitting the sanding bit to be used
for a longer period of
time. When the last layer of sandpaper is worn away, a new strip can be easily
added.
An alternate embodiment of the present invention is shown in figure ?b. Bit 40
consists
of a conical barrel portion 42 coaxially mounted to a drill shaft 44. Barrel
portion 42 has first
end 49 and second end 48. Slot 46 bifi~rcates end 48. Barrel portion 42 tapers
away from shaft
44 such that the cross-sectional diameter of end 48 is less than the cross-
sectional diameter of
end 49. As with the previous embodiment, an elongated strip of sandpaper is
inserted into slot
46 and then wound around the barrel in a spiral fashion. Since barrel 42 is
conical, the sandpaper
may be wrapped around the barrel to form a flared horn as indicated in figure
8. This flared horn
structure is relatively flexible, allowing to the user to apply more uniform
and gentle pressure
onto the surface of the item being worked with (not shown).
Another alternate embodiment of the present invention is shown in figure 7c.
Bit 50
consists of a conical barrel portion 52 coaxially mounted to drill shaft 54.
Barrel portion 52 has
first end 59 and second end 58. Slot 56 bifurcates end 58. Barrel portion 52
tapers towards shaft
54 such that the cross-sectional diameter of end 58 is greater than the cross-
sectional diameter of
end 59. As with the previous embodiments, an elongated strip of sandpaper is
inserted into slot
56 and then wound around the barrel in a spiral fashion. As in the previous
embodiment, since
barrel 52 is conical, the sandpaper may be wrapped around the barrel to form a
flared horn as
~.c~~.
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indicated in figure 9. This flared horn structure is relatively flexible,
allowing to the user to
apply more uniform and gentle pressure onto the surface of the item being
worked with (not
shown). The flared horn structure as shown in figures 8 and 9 are suitable for
sanding uneven
surfaces.
A specific embodiment of the present invention has been disclosed; however,
several
variations of the disclosed embodiment could be envisioned as within the scope
of this invention.
It is to be understood that the present invention is not limited to the
embodiments described
above, but encompasses any and all embodiments within the scope of the
following claims.
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