U.S. patent application number 11/277142 was filed with the patent office on 2007-09-27 for foot sanding disc with a flat abrasive sanding surface, smooth periphery and slip-on shaft.
Invention is credited to Hong (Jenny) Tran.
Application Number | 20070221238 11/277142 |
Document ID | / |
Family ID | 38532063 |
Filed Date | 2007-09-27 |
United States Patent
Application |
20070221238 |
Kind Code |
A1 |
Tran; Hong (Jenny) |
September 27, 2007 |
Foot Sanding Disc with a Flat Abrasive Sanding Surface, Smooth
Periphery and Slip-On Shaft
Abstract
Afoot sanding disc includes a hub; a concentric abrasive disc
having a diameter smaller than the hub diameter. A shaft
concentrically attached to the bottom surface of the hub has a free
end and a central cavity of a determined shape extending from the
free end to a determined depth into the shaft. The shaft is shaped,
sized and configured to matingly receive within the cavity a
portion of a mandrel attached to an output shaft of a motorized
rotary tool, thereby operably coupling the disc to an output shaft
of the motarized rotary tool. A circular recess concentrically
formed in a top surface of the hub receives the abrasive disc. The
abrasive disc is devoid of a central aperture. The hub may include
a thermochromic material in a concentration effective to cause a
change in color when the hub reaches a predetermined temperature.
The hub may also be rigid or flexible.
Inventors: |
Tran; Hong (Jenny);
(Jacksonville, FL) |
Correspondence
Address: |
MARK YOUNG, P.A.
12086 FORT CAROLINE ROAD
UNIT 202
JACKSONVILLE
FL
32225
US
|
Family ID: |
38532063 |
Appl. No.: |
11/277142 |
Filed: |
March 21, 2006 |
Current U.S.
Class: |
132/73.6 |
Current CPC
Class: |
A61B 17/54 20130101;
A61B 2017/00398 20130101; A61B 2017/320004 20130101 |
Class at
Publication: |
132/073.6 |
International
Class: |
A45D 29/05 20060101
A45D029/05 |
Claims
1. A foot sanding disc comprising a hub having a top surface, a
bottom surface, and a hub diameter, an abrasive disc having a disc
diameter smaller than the hub diameter, said abrasive disc being
concentrically mounted to the top surface of said hub, and a shaft
concentrically attached to the bottom surface of said hub, said
shaft having a free end and a central cavity of a determined shape
extending from said free end to a determined depth into the shaft,
said shaft being configured to matingly receive within said cavity
a portion of a mandrel attached to an output shaft of a motorized
rotary tool, thereby operably coupling the disc to an output shaft
of the motarized rotary tool.
2. A foot sanding disc according to claim 1, said disc further
comprising a circular recess concentrically formed in the top
surface of the hub, said circular recess being configured to
concentrically receive the abrasive disc, and having a circular
recess diameter of slightly larger than the disc diameter and
smaller than the hub diameter.
3. A foot sanding disc according to claim 2, wherein the abrasive
disc has a disc thickness, and the circular recess has a depth
approximately the same as the disc thickness.
4. A foot sanding disc according to claim 2, wherein the abrasive
disc has a disc thickness, and the circular recess has a depth
approximately less than the disc thickness.
5. A foot sanding disc according to claim 2, wherein the circular
recess has a planar surface for engaging the abrasive disc, and
said abrasive disc is bonded to the planar surface.
6. A foot sanding disc according to claim 2, wherein the abrasive
disc is comprised of a substrate coated with an abrasive material,
and the abrasive disc is devoid of a central aperture.
7. A foot sanding disc according to claim 2, wherein the circular
recess has a planar bottom surface, and said abrasive disc is
integrally formed on said planar bottom surface, said abrasive disc
being comprised of an abrasive material bonded directly to the
planar bottom surface.
8. A foot sanding disc according to claim 2, wherein the central
cavity includes a roughened surface.
9. A foot sanding disc according to claim 2, wherein the central
cavity includes a tapered configuration.
10. A foot sanding disc according to claim 2, wherein the central
cavity has a cross sectional shape and size compatible with the
mandrel.
11. A foot sanding disc according to claim 10, wherein the central
cavity has a cross section from the group consisting of circular,
oval, elliptical, triangular, square, pentagonal or octagonal, and
the mandrel has a corresponding cross section.
12. A foot sanding disc according to claim 11, wherein the central
cavity is configured manual installation and removal of the foot
sanding disc on the mandrel without any tools.
13. A foot sanding disc according to claim 2, wherein the hub and
shaft are comprised of material from the group consisting of
polyvinyl chloride (PVC), polyethylene, polypropylene, polystyrene,
acrylics, cellulosics, acrylonitrile-butadiene-styrene terpolymers,
urethanes, thermo-plastic resins, thermo-plastic elastomers (TPE),
acetal resins, polyamides, polycarbonates and polyesters.
14. A foot sanding disc according to claim 2, wherein the hub is
comprised of a thermochromic material in a concentration effective
to cause a change in color when the hub reaches a predetermined
temperature.
15. A foot sanding disc according to claim 2, wherein the hub is
comprised of a disc from the group consisting of a rigid disc and a
flexible disc.
Description
FIELD OF THE INVENTION
[0001] This invention generally relates to a pedicure device, and
more particularly, to a foot sanding disc with a flat abrasive
surface, smooth periphery, and slip-on shaft that facilitates
manual installation on a motorized rotary tool.
BACKGROUND
[0002] During a pedicure, calluses and dry, flaky skin are abraded
or scraped from the bottom of the feet. Typically, the feet are
soaked in a warm bath. Once the warm water has softened the skin on
the feet, the bottoms of the feet are scrubbed with a pedicure
sander 110 comprised of an abrasive sanding pad attached to a
durable plastic handle, a callus rasp 120, a pumice stone 130,
and/or a similar abrasive article, as shown in FIG. 1.
Additionally, some technicians will use a corn and callus plane 140
comprised of a stainless steel head with a raised shaving blade to
slice thick, tough callus from the feet.
[0003] Unfortunately, pedicures performed using such conventional
instruments are strenuous, tedious tasks. A technician performing
the pedicure must maintain a hunched position while exerting
appreciable force in performing a repetitive sanding motion for
several minutes. In the course of a workday, a technician may
require several breaks to recover from fatigue. Over the long term,
the repetitive strain leads to a high rate of attrition as well as
costly workplace related injuries such as carpal tunnel
syndrome.
[0004] Additionally, some of the conventional instruments present
hazards. In particular, a callus plane may cause serious injury if
used improperly.
[0005] To reduce the risks and deleterious effects of the manual
process, several rotary and belt sanders have been devised for
grooming feet. While such known devices obviate a repetitive
sanding motion and reduce the risk of severe injury, they suffer
certain shortcomings. For example, the known disc-shaped sanding
elements of such devices are recessed slightly, reducing the
effectiveness of abrasion. Additionally, the sanding elements of
such devices are often difficult and time consuming to replace.
Furthermore, the sanding elements of such devices are not suitable
for use on conventional rotary machines. Instead, they must be used
on proprietary motorized devices.
[0006] Concomitantly, sanding elements for conventional motorized
sanding tools are not well suited for pedicures. Such sanding
elements typically require tools for installation and removal,
making these tasks inconvenient. Additionally, disc-shaped sanding
elements typically have an exposed screw head for fastening the
disc to a pad, which poses a serious risk of injury to sensitive
feet. Furthermore, many disc-shaped sanding elements have exposed
peripheries, which may cut into and seriously injure feet.
[0007] The invention is directed to overcoming one or more of the
problems and solving one or more of the needs as set forth
above.
SUMMARY OF THE INVENTION
[0008] To solve one or more of the problems set forth above, in an
exemplary implementation of the invention, a foot sanding disc is
provided. The foot sanding disc includes a hub having a top
surface, a bottom surface, and a hub diameter; an abrasive disc
having a disc diameter smaller than the hub diameter, the abrasive
disc being concentrically mounted to the top surface of the hub;
and a shaft concentrically attached to the bottom surface of the
hub, the shaft having a free end and a central cavity of a
determined shape extending from the free end to a determined depth
into the shaft, the shaft being configured to matingly receive
within the cavity a portion of a mandrel attached to an output
shaft of a motorized rotary tool, thereby operably coupling the
disc to an output shaft of the motarized rotary tool. The central
cavity has a cross sectional shape (e.g., circular, oval,
elliptical, triangular, square, pentagonal or octagonal) and size
compatible with the mandrel, and may include a roughened surface or
a tapered configuration.
[0009] In another aspect of the invention, a circular recess
concentrically formed in the top surface of the hub is configured
to concentrically receive the abrasive disc. The abrasive disc has
a determined disc thickness, and the circular recess has a depth
approximately the same as or slightly less than the disc thickness.
The circular recess has a planar surface for engaging the abrasive
disc, and the abrasive disc is either bonded to the planar surface
or integrally formed on the planar surface. The abrasive disc is
devoid of a central aperture.
[0010] In yet another aspect of the invention, the hub and shaft
are comprised of polyvinyl chloride (PVC), polyethylene,
polypropylene, polystyrene, acrylics, cellulosics,
acrylonitrile-butadiene-styrene terpolymers, urethanes,
thermo-plastic resins, thermo-plastic elastomers (TPE), acetal
resins, polyamides, polycarbonates and/or polyesters. The hub may
also include a thermochromic material in a concentration effective
to cause a change in color when the hub reaches a predetermined
temperature. The hub may be rigid or flexible.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The foregoing and other aspects, objects, features and
advantages of the invention will become better understood with
reference to the following description, appended claims, and
accompanying drawings, where:
[0012] FIG. 1 conceptually illustrates prior art pedicure devices
to illustrate principles of the invention; and
[0013] FIG. 2 provides a top perspective view of an exemplary foot
sanding disc with an abrasive disc in accordance with principles of
the invention; and
[0014] FIG. 2A provides a top perspective view of an exemplary foot
sanding disc without an abrasive disc in accordance with principles
of the invention; and
[0015] FIG. 3 provides a bottom view of an exemplary foot sanding
disc in accordance with principles of the invention; and
[0016] FIG. 4 provides a side view of an exemplary foot sanding
disc in accordance with principles of the invention; and
[0017] FIG. 5 provides another side view of an exemplary foot
sanding disc in accordance with principles of the invention;
and
[0018] FIG. 6 provides a detail view of encircled portion B-B from
FIG. 4 in accordance with principles of the invention; and
[0019] FIG. 7 provides a bottom perspective view of an exemplary
foot sanding disc in accordance with principles of the invention;
and
[0020] FIG. 8 provides a side view of an exemplary mandrel for use
with a foot sanding disc in accordance with principles of the
invention; and
[0021] FIGS. 9A through 9D conceptually illustrate dimensioned
views of an exemplary foot sanding disc in accordance with
principles of the invention.
[0022] Those skilled in the art will appreciate that FIGS. 1
through 8 are not intended to be drawn to any particular scale; the
invention is not limited to the dimensions or proportions shown in
FIGS. 9A through 9D; and the Figures are not intended to illustrate
every embodiment of the invention. The invention is not limited to
the exemplary embodiments depicted in the Figures or the shapes,
relative sizes, ornamental aspects, dimensions or proportions shown
in the Figures.
DETAILED DESCRIPTION
[0023] In an exemplary implementation of the invention, a foot
sanding disc according to principles of the invention includes a
flat abrasive sanding surface, smooth periphery and slip-on shaft
for manual attachment to a rotary tool without the need for special
tools. Referring now to FIG. 2, a top perspective view of an
exemplary foot sanding disc in accordance with principles of the
invention is shown. A disc-shaped hub 210 supports a concentric
abrasive disc 250. The hub 210 includes a top surface 212 upon
which the abrasive disc 250 is mounted, and a bottom surface 208
from which a shaft 230 stems.
[0024] The diameter of the hub 210 is larger than the diameter of
the concentric abrasive disc 250. Thus, the periphery of the
abrasive disc 250 does not extend beyond the periphery of the hub
210. This reduces the risk of cutting injuries caused by exposed
edges of the abrasive disc 250. By way of example and not
limitation, the hub 210 may have a diameter of approximately 1.55
inches, while the concentric abrasive disc may have a diameter of
approximately 1.45 inches, as conceptually shown in FIGS.
9A-9D.
[0025] As shown in FIGS. 2A and 4 through 6, a circular recess 255
is concentrically formed in the top surface 212 of the hub 210 to
receive the concentric abrasive disc 250. The diameter of the
circular recess 255 is slightly larger than the diameter of the
concentric abrasive disc 250. The depth of circular recess 255 is
the same as or slightly less than the thickness of the concentric
abrasive disc 250. Thus, the periphery of the abrasive disc 250
does not extend beyond the periphery of the circular recess 255. By
way of example and not limitation, the circular recess may have a
diameter of approximately 1.46 inches, while the concentric
abrasive disc may have a diameter of approximately 1.45 inches. The
depth of the circular recess may be approximately 0.01 to 0.05
inches, while the thickness of the concentric abrasive disc may be
approximately 0.01 to 0.05 inches. The abrasive surface of the
concentric abrasive disc 250 is exposed and level with or slightly
above the top surface of the hub 210 to facilitate abrasive contact
with calluses and dry, flaky skin.
[0026] The concentric abrasive disc 250 is preferably comprised of
a substrate, such as paper or fabric, coated with an abrasive
material such as a silica, garnet, silicon carbide, or aluminum
oxide, suitable for smoothing and polishing. The disc 250 is devoid
of a central aperture. The grit of the abrasive face could be
calibrated based on the foot surface to be sanded and the type of
finish desired. The disc may have a very fine, fine, medium,
coarse, or very coarse abrasive surface grit.
[0027] In an alternative implementation, the concentric abrasive
disc 250 may be integrally formed with the foot sanding disc. In
such an embodiment, abrasive material such as a silica, garnet,
silicon carbide, or aluminum oxide, may be bonded directly to the
surface of the circular recess 255, with the abrasive surface being
approximately level with or slightly above the top surface 212 of
the hub 210 to facilitate abrasive contact with calluses and dry,
flaky skin.
[0028] The circular recess 255 of the top surface of the hub 210
has a planar surface 257 for engaging the abrasive disc. The
concentric abrasive disc 250 is preferably bonded to the planar
surface 257 of the circular recess 255 of the top surface of the
hub 210. A layer of glue, adhesive, or other bonding agent may be
disposed over substantially the entire side of the concentric
abrasive disc 250 which will contact the circular recess 255 of the
top surface of the hub 210. Thus, the concentric abrasive disc 250
can be affixed to the hub 210 without use of a screw or other
mechanical fastener that may interfere with a pedicure or harm
feet.
[0029] As shown in FIGS. 3 through 7, the bottom surface 208 of the
hub 210 may optionally include a recessed area 220 or may be flat
or feature some other configuration. Advantageously, a recessed
area conserves material and reduces overall weight. Advantageously,
a lightweight hub requires less rotational force to spin and
reduces the weight borne by the technician, thereby reducing worker
fatigue. Finally, thinner hubs require less material to produce,
and are inherently less expensive. Strengthening ribs and similar
structures may be added to a thin hub, to the extent necessary to
maintain structural integrity.
[0030] Referring now to FIGS. 3, 4, 5 and 7, the shaft 230 of the
foot sanding disc has free end 232 with a cavity 240 of a
determined interior depth and an inner circumference that is
configured to matingly receive the distal end 820 of a mandrel 800,
as described below. The cavity 240 may include a roughened surface
(i.e., textured cavity surfaces with a high coefficient of
friction) and/or a tapered configuration to frictionally engage the
mandrel. While the cavity 240 shown in FIGS. 3-5, 7 and 8 is
generally circular in cross section, other shapes may be used
provided that they are compatible with the shape of the mandrel
800. For example, the cavity 240 may be keyed (i.e., shaped) to
securely engage the mandrel 800 without slippage during rotation.
By way of example and not limitation, a cavity with an oval,
elliptical, triangular, square, pentagonal or octagonal cross
section may be used to securely engage a mandrel with an oval,
elliptical, triangular, square, pentagonal or octagonal cross
section, respectively.
[0031] Advantageously, the shaft 230 enables manual installation
and removal of the foot sanding disc without any tools. A user may
manually slide the shaft 230 of the foot sanding disc onto and off
of a mandrel 800 coupled to a rotary tool. Such installation and
removal requires relatively little effort and time to
accomplish.
[0032] An exemplary mandrel 800 as conceptually illustrated in FIG.
8, includes a distal end 820, a flange 815 and a proximal end 810.
The distal end 820 includes a cross-sectional shape that is
compatible with the cavity 240 of the shaft 230. The proximal end
810 is configured (i.e., sized and shaped) for coupling to a
conventional rotary hand tool equipped with a collet and a collet
nut, which are coupled to the output shaft of the rotary tool. The
flange 815, which is optional, provides a backstop and a structure
for distributing stress along the free end of shaft 230. By way of
example and not limitation, the proximal end 810 may feature a
generally circular cross section. Likewise, the distal end 820 is
configured (i.e., sized and shaped) to securely fit within the
cavity 240 of the shaft 230. Various shapes may be used for the
distal end 820, provided that the shape is compatible with the
cavity 240 of the shaft 230. For example, the distal end 820 may be
keyed (i.e., shaped) to securely engage the cavity 240 of the shaft
230 without slippage during rotation. By way of example and not
limitation, a distal end 820 with a square, pentagonal or octagonal
cross section may be used to securely engage a cavity 240 of a
shaft 230 with a square, pentagonal or octagonal cross section,
respectively. The mandrel may be comprised of any materials
suitable for drill bits and the like, such as metals, alloys and
composites.
[0033] The hub 210 and shaft 230 are preferably comprised of a
rigid plastic or polymeric material, such as polyvinyl chloride
(PVC), polyethylene, polypropylene, polystyrene, acrylics,
cellulosics, acrylonitrile-butadiene-styrene terpolymers,
urethanes, thermo-plastic resins, thermo-plastic elastomers (TPE),
acetal resins, polyamides, polycarbonates and polyesters. While
many other materials may be used alone or in combination with the
aforementioned materials and/or other materials, without departing
from the scope of the present invention, preferably the material is
relatively inexpensive and durable, easy to use in manufacturing
operations and results in an aesthetically acceptable product. The
material may further include additives to provide desired
properties such as desired colors, structural characteristics,
glow-in-the dark properties and thermal reactivity (e.g., color
changes according to heat).
[0034] By way of example and not limitation, the hub 210 and shaft
230 may optionally be formulated to change color when they reach a
predetermined or higher temperature. High temperatures attained
during extended periods of use may serve as a safety indicator.
This can be accomplished by mixing a thermochromic additive to the
base material in an amount that is sufficient to achieve a desired
color changing range. As an example, a mixture of approximately 10%
to 25% (pbw) of Matsui Interantional Co., Inc.'s Chromicolor.RTM.
concentrate may be introduced to the base material, to provide a
plastic structure that visibly changes color at a determined
elevated temperature, such as approximately 105, 110 or 120 degrees
Fahrenheit. A color change will alert a technician to the
possibility of excessive friction and risk of possible injury.
[0035] The hub 210 is preferably sufficiently strong and heat
resistant such that the hub does not structurally fail from the
stresses and heat generated during use. Within these parameters,
the hub 210 may be either rigid or somewhat flexible.
Illustratively, certain embodiments of the invention may utilize a
hub that is formulated to exhibit flexibility and resiliency such
that the hub can conform somewhat to the contours of a foot and
return to its original shape without appreciable permanent
deformation during normal use.
[0036] The hub 210 and shaft 230 may be produced using any suitable
manufacturing techniques known in the art for the chosen material,
such as (for example) injection, compression, structural foam,
blow, or transfer molding; polyurethane foam processing techniques;
vacuum forming; and casting. Preferably the manufacturing technique
is suitable for mass production at relatively low cost per unit,
and results in an aesthetically acceptable product with a
consistent acceptable quality.
[0037] In use, the foot sanding disc is operably coupled to a
rotary hand tool. The rotary hand tool contains a motor with a
rotary output shaft. The mandrel 800 is mounted to the rotary hand
tool by a collet and a collet nut, which are coupled to the output
shaft of the rotary tool. The shaft 230 of the foot sanding disc
has a cavity of a determined interior depth and an inner
circumference that is configured to matingly receive the distal end
820 of the mandrel 800. Rotation of the output shat of the rotary
tool induces a rotation of the mandrel 800, which induces a
rotation of shaft 230, which induces rotation of the hub 210 and
the attached abrasive disc 250, thereby allowing sanding of a foot
by applying the abrasive face of the disc 250 thereto.
[0038] For illustrative purposes, FIGS. 9A through 9D conceptually
illustrate dimensioned views of a preferred foot sanding disc in
accordance with principles of the invention. Those skilled in the
art will appreciate that the invention is not limited to the
dimensions or proportions shown in FIGS. 9A through 9D, and that
the Figures are not intended to illustrate every embodiment of the
invention.
[0039] While the invention has been described in terms of various
embodiments, implementations and examples, those skilled in the art
will recognize that the invention can be practiced with
modification within the spirit and scope of the appended claims
including equivalents thereof. The foregoing is not intended to
limit the invention to the exact construction and operation shown
and described. Alternative embodiments of the invention, including
variations in size, materials, components, shape, form, function,
manner of operation, assembly and use that are obvious to one
skilled in the art are intended to be encompassed by the invention.
Accordingly, all suitable modifications and equivalents may be
resorted to, falling within the scope of the invention.
* * * * *