U.S. patent application number 13/907125 was filed with the patent office on 2013-12-05 for diamond impregnated polishing pad with diamond pucks.
The applicant listed for this patent is Webster Ryan. Invention is credited to Webster Ryan.
Application Number | 20130324021 13/907125 |
Document ID | / |
Family ID | 49670793 |
Filed Date | 2013-12-05 |
United States Patent
Application |
20130324021 |
Kind Code |
A1 |
Ryan; Webster |
December 5, 2013 |
DIAMOND IMPREGNATED POLISHING PAD WITH DIAMOND PUCKS
Abstract
An abrasive pad for use on hard surfaces is described. The pad
includes a fibrous, non-woven body with an abrasive coating
containing diamond particles applied to a first side thereof. A
plurality of diamond-impregnated abrasive elements is affixed to
the first side. One or more of the abrasive elements are located
near an outer edge of the first side of the pad. A resilient
reinforcing material is applied to the outer edge of the pad to
resist compression of the pad and to maintain adjacent abrasive
elements parallel to a surface being worked on. The abrasive
elements at least partially recess into the pad body and enable
simultaneous contact of the abrasive elements and the pad with the
surface being worked on. Thereby, multiple surface-preparation
steps, e.g. polishing and burnishing, are completed simultaneously
reducing surface-preparation time and eliminating separate
surface-preparation steps.
Inventors: |
Ryan; Webster; (Shawnee,
KS) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ryan; Webster |
Shawnee |
KS |
US |
|
|
Family ID: |
49670793 |
Appl. No.: |
13/907125 |
Filed: |
May 31, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61789682 |
Mar 15, 2013 |
|
|
|
61653885 |
May 31, 2012 |
|
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Current U.S.
Class: |
451/529 |
Current CPC
Class: |
B24D 13/147 20130101;
B24D 11/00 20130101; B24B 7/186 20130101 |
Class at
Publication: |
451/529 |
International
Class: |
B24D 11/00 20060101
B24D011/00 |
Claims
1. An abrasive pad comprising: a pad body having a first surface, a
second surface opposite the first surface, and a circumferential
face extending between the perimeters of the first and second
surfaces; a plurality of abrasive elements affixed to the second
surface of the pad body, at least one of the abrasive elements
being located proximate to the perimeter of the second surface; and
a reinforcing material applied to the circumferential face, the
reinforcing material reinforcing the pad body against compression
at the circumferential face and proximate to the at least one
abrasive element, and the reinforcing material maintaining a
working face of the at least one abrasive element substantially
parallel to a surface being worked on.
2. The abrasive pad of claim 1, further comprising: an abrasive
coating applied to at least a portion of the second surface.
3. The abrasive pad of claim 2, wherein the abrasive coating
includes one or more of diamonds and diamond particles.
4. The abrasive pad of claim 1, wherein the plurality of abrasive
elements includes one or more of diamonds and diamond particles
coated thereon or impregnated therein.
5. The abrasive pad of claim 1, wherein the plurality of abrasive
elements have a low profile with a thickness of approximately 0.2
millimeters to about five millimeters.
6. The abrasive pad of claim 1, wherein the plurality of abrasive
elements at least partially recess into the pad body and the
plurality of abrasive elements and the second surface of the pad
body simultaneously contact and abrade the surface being worked
on.
7. The abrasive pad of claim 1, wherein the reinforcing material is
resilient.
8. The abrasive pad of claim 8, wherein the reinforcing material
comprises one or more layers of one or more of a resin, glue,
rubber, or plastic.
9. The abrasive pad of claim 1, wherein the reinforcing material is
applied to the entire circumferential face.
10. The abrasive pad of claim 1, wherein the reinforcing material
is applied to the circumferential face at locations proximate to
one or more of the plurality of abrasive elements.
11. A combination polishing and burnishing pad for use on hard
surfaces, the pad comprising: a pad body having a first surface, a
second surface opposite the first surface, and a circumferential
face extending between the perimeters of the first and second
surfaces; a diamond impregnated coating applied to at least a
portion of the second surface and configured for burnishing a hard
surface; and a plurality of low-profile abrasive elements affixed
to the second surface of the pad body and configured for polishing
the hard surface, the abrasive elements at least partially
recessing into the pad to provide simultaneous contact of the
plurality of abrasive elements and the coating on the second
surface with the hard surface to simultaneously polish and burnish
the hard surface.
12. The combination polishing and burnishing pad of claim 11,
further comprising: a reinforcing material applied to the
circumferential face, the reinforcing material reinforcing the pad
body against compression at the circumferential face, and the
reinforcing material maintaining a working face of the at least one
abrasive element substantially parallel to a surface being worked
on.
13. The combination polishing and burnishing pad of claim 12,
wherein the reinforcing material is applied to the entire
circumferential face.
14. The combination polishing and burnishing pad of claim 12,
wherein the reinforcing material is applied to the circumferential
face at locations proximate to one or more of the plurality of
abrasive elements.
15. An abrasive pad for use on hard surfaces, the pad comprising: a
pad body of a fibrous, non-woven material having a first surface, a
second surface opposite the first surface, and a circumferential
surface extending between the perimeters of the first and second
surfaces; a diamond impregnated coating applied to the second
surface, the coating having a first grit; a plurality of abrasive
elements coupled to the working surface, the abrasive elements
having diamond particles impregnated therein and having a second
grit that is more coarse than the first grit; and a reinforcing
material applied to at least a portion of the circumferential
surface proximate to an abrasive element of the plurality of
abrasive elements, the reinforcing material reinforcing the pad
body against compression proximate to the edge face.
16. The abrasive pad of claim 15, wherein the reinforcing material
maintains the at least one abrasive element substantially parallel
to a surface being worked on.
17. The abrasive pad of claim 15, wherein the pad body is
compressible to enable at least partial conformance to an uneven
surface being worked on.
18. The abrasive pad of claim 17, wherein the reinforcing material
is applied to the entire circumferential surface.
19. The abrasive pad of claim 15, wherein the coating on the second
surface is configured for burnishing, the abrasive elements are
configured for polishing, and the pad enables a burnished finish to
be achieved without the use of separate polishing and burnishing
pads.
20. An abrasive pad comprising: a pad body having a working
surface; and a plurality of abrasive elements affixed to said
working surface, each of said abrasive elements having at least
three sides wherein at least two of said sides converge toward each
other as they extend toward a center of said pad body.
21. The abrasive pad as in claim 20 wherein said abrasive element
has a curved side positioned proximate an outer periphery of said
abrasive pad and having a radius of curvature similar to a radius
of curvature of said abrasive pad.
22. An abrasive pad comprising: a fibrous pad body having a first
surface and a second surface opposite the first surface with an
abrasive coating applied to at least a portion of the second
surface; said abrasive coating including a plurality of particles
of an abrasive material having a first grit; a plurality of
abrasive elements affixed to the second surface of the pad body;
said abrasive element including a plurality of particles of the
abrasive material having a second grit embedded therein; and
wherein the first grit is different than the second grit.
23. The abrasive pad as in claim 22 wherein the abrasive material
comprises diamond particles.
24. The abrasive pad as in claim 22 wherein the first grit is
greater than the second grit.
25. The abrasive pad as in claim 24 wherein the first grit is
approximately 1.5 to 2.5 times greater than the second grit.
26. The abrasive pad as in claim 22 wherein the first grit is less
than the second grit.
27. The abrasive pad as in claim 26 wherein the second grit is
approximately 1.5 to 2.5 times greater than the first grit.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of provisional
application Ser. No. 61/653,885 filed May 31, 2012, and provisional
application Ser. No. 61/789,682 filed Mar. 15, 2013, the contents
of which are incorporated herein by reference.
BACKGROUND
[0002] Numerous techniques are known for grinding, polishing, and
finishing hard surfaces like concrete, terrazzo, and stone floors.
These techniques employ various abrasive materials and chemicals
that work on the surface to grind and polish the surface to a
desired finish. For hard surfaces, like concrete flooring, the
abrasive materials often employ diamonds or diamond particles that
are embedded in a metallic, resinous, or similar binder. The
diamond-impregnated abrasives can be coated on a variety of carrier
pads or can be molded into abrasive components that are then
attached to a carrier pad or carrier plate. For example, U.S. Pat.
No. 794,495 to Gorton and U.S. Pat. No. 2,001,911 to Wooddell et
al. describe cloth, fiber, thin sheet metal, or paper carrier disks
with a plurality of abrading elements attached to the surfaces
thereof. U.S. Pat. No. 6,234,886 to Rivard et al. describes a
non-woven carrier pad with an abrasive coating applied to a working
surface thereof and a plurality of abrasive sheets, e.g. sandpaper,
coupled to the working surface. And U.S. Pat. No. 7,204,705 to
Thysell describes a non-woven pad with recesses in which
spring-biased, diamond-impregnated, resinous elements are
disposed.
[0003] These carrier pads and/or molded abrasive components are
coupled to a rotary grinding or polishing machine. Common grinding
and polishing machines include an electric or propane motor
rotatably coupled to a single platen or to a plurality of platens
in a planetary arrangement. The carrier pad and/or the molded
abrasive components are coupled to the platen and are rotated while
in contact with a floor surface to abrade the surface.
[0004] Preparation of surfaces from a rough, coarse-cut material to
a polished, high-shine, finished product employs a variety of
steps, each of which employs a carrier pad and/or abrasive element
having a different grit or coarseness. The preparation begins with
more abrasive materials and progresses through a number of
sequentially finer grit materials until a desired finish is
achieved. For example, one common progression for preparing
concrete begins with a 30-40 grit metal-bonded diamond particle
abrasive elements and then proceeds through similar 80 and 150 grit
abrasive elements. The concrete surface is then typically polished
using 100 grit abrasive elements of resin-bonded diamond particles
followed by similar abrasive elements of 200 grit and successively
higher grits to a desired finish where each grit is typically
double the previous grit.
SUMMARY
[0005] Embodiments of the invention are defined by the claims
below, not this summary. A high-level overview of various aspects
of the invention are provided here for that reason, to provide an
overview of the disclosure, and to introduce a selection of
concepts that are further described in the Detailed-Description
section below. This summary is not intended to identify key
features or essential features of the claimed subject matter, nor
is it intended to be used as an aid in isolation to determine the
scope of the claimed subject matter.
[0006] In brief, this disclosure describes, among other things, an
abrasive pad for use on hard surfaces, such as concrete, terrazzo,
or stone floors. The abrasive pad includes a carrier pad and a
plurality of abrasive elements affixed thereto. A reinforcing
material may be disposed on an edge of the carrier pad. A working
surface of the carrier pad is coated or impregnated with an
abrasive, such as a diamond-impregnated resin having a grit
suitable for grinding, polishing or burnishing the surface. The
abrasive elements comprise low-profile, diamond-impregnated,
resinous disks or resinous abrasive elements of a variety of shapes
including circular, triangular, or quadrilateral, and certain
shapes may have at least one side of the shape curved. The abrasive
elements are affixed to the working surface of the carrier pad and
have a grit suitable for grinding, polishing or burnishing the
surface. The edge of the carrier pad is coated with the reinforcing
material to resist compression of the carrier pad near the edge. As
such, abrasive elements affixed near the edge are maintained
substantially parallel to the working surface.
[0007] In operation, the abrasive pad is coupled to a grinding or
polishing machine as known in the art and placed in contact with
the surface to be worked on. The abrasive elements compress the
overlying carrier pad and at least partially recess into the
carrier pad. Thereby, both the abrasive elements and the abrasive
coating on the carrier pad are simultaneously in contact with the
surface and simultaneously grind, burnish and/or polish the
surface. The combination of the abrasive elements and the carrier
pad provide a cutting depth similar to that achieved with polishing
but with a surface finish comparable to a burnished surface. And
this surface finish is achieved in less time than separate
polishing and burnishing steps using similar grit abrasive
materials.
DESCRIPTION OF THE DRAWINGS
[0008] Illustrative embodiments of the invention are described in
detail below with reference to the attached drawing figures, and
wherein:
[0009] FIG. 1 is a perspective view of an abrasive pad depicted in
accordance with an embodiment of the invention;
[0010] FIG. 2 is a partial cross-sectional view of the abrasive pad
of FIG. 1 depicted in accordance with an embodiment of the
invention;
[0011] FIG. 3 is a perspective view of an abrasive pad depicted in
accordance with another embodiment of the invention;
[0012] FIG. 4 is an elevational, cross-sectional view of an
abrasive pad in the prior art coupled to a floor-finishing machine
depicting lifting of an abrasive disc away from a surface being
worked on;
[0013] FIG. 5 is an elevational, cross-sectional view of the
abrasive pad of FIG. 1 coupled to a floor-finishing machine in
accordance with an embodiment of the invention;
[0014] FIG. 6 is an enlarged view of a working surface of the
abrasive pad of FIG. 1 at the location 6 depicting fibers with
abrasive resin thereon in accordance with an embodiment of the
invention; and
[0015] FIG. 7 is an elevational cross-sectional view of an abrasive
pad depicting a reinforcing material on a circumferential edge in
accordance with an embodiment of the invention.
[0016] FIG. 8 is a perspective view of a triangular or wedge shaped
abrasive pad depicted in accordance with an embodiment of the
invention.
[0017] FIG. 9 is a partial cross-sectional view of the abrasive pad
of FIG. 8 depicted in accordance with an embodiment of the
invention.
[0018] FIG. 10 is a perspective view of a trapezoidal abrasive pad
depicted in accordance with an embodiment of the invention.
[0019] FIG. 11 is a partial cross-sectional view of the abrasive
pad of FIG. 10 depicted in accordance with an embodiment of the
invention.
[0020] FIG. 12 is a plan view of the abrasive pad of FIG. 10
depicted in accordance with an embodiment of the invention.
DETAILED DESCRIPTION
[0021] The subject matter of select embodiments of the invention is
described with specificity herein to meet statutory requirements.
But the description itself is not intended to necessarily limit the
scope of the claims. Rather, the claimed subject matter might be
embodied in other ways to include different components, steps, or
combinations thereof similar to the ones described in this
document, in conjunction with other present or future technologies.
Terms should not be interpreted as implying any particular order
among or between various steps herein disclosed unless and except
when the order of individual steps is explicitly described.
[0022] Embodiments of the invention are described herein with
respect to finishing hard surfaces like concrete, terrazzo, and
stone floor surfaces. However, embodiments of the invention are not
so limited and might be configured for use on other hard or soft
surfaces, such as glass, metals, wood, ceramics, or the like.
Further, embodiments are described with respect to applications
using a rotary grinding or polishing apparatus with a single platen
as is known in the art. But, embodiments of the invention are
configurable for use with other grinding/polishing apparatus
including those with planetary platen configurations, as well as
walk-behind, and ride-on models, among others. Exemplary apparatus
include autoscrubbers, swing-machines, and planetary grinders,
among others known in the art.
[0023] With reference to FIGS. 1 and 2, an abrasive pad 10 is
described in accordance with an embodiment of the invention.
Embodiments of the invention are described herein with respect to
the drawings in which reference numerals are employed to identify
particular components or features. Similar elements in the various
embodiments depicted are provided with reference numerals having
matching second and third digits but with differing first digits,
e.g. element 110 is similar to elements 210, 210, etc. Such is
provided to avoid redundant description of similar features of the
elements but is not intended to indicate in any way that the
elements are identical.
[0024] The abrasive pad 10 comprises a body 12 and a plurality of
abrasive elements 15 affixed thereto. The body 12 comprises a
non-woven, lofty, fibrous pad having a non-working surface or side
18, a working surface 20 opposite the non-working side 18, and a
circumferential edge 22. As best depicted by FIG. 6, the non-woven,
lofty, fibrous material comprises polyester, nylon, or other fibers
48 that are adhered together by one or more glues, adhesives, or
the like, or by heating to cause partial melting and fusing of the
fibers together as known in the art. In another embodiment, the
body 12 is comprised of one or more woven materials like wool,
nylon, or cotton, or non-woven materials like paper, rubber, metal,
plastic, or similar materials.
[0025] The body 12 has a generally flat, cylindrical shape but can
be configured as desired for a given application. As depicted in
FIGS. 1-2, the body 12 has an industry standard twenty-seven inch
diameter and an approximately 1 or 1/2 inch thickness but is not
limited to any particular dimensions. The density and abrasiveness,
among other inherent properties of the body 12 are also
configurable to provide characteristics desired for a particular
application. As depicted in FIG. 1, the body 12 includes a central
aperture 14 that can be used for mounting on a rotary grinding,
burnishing or polishing machine, such as a swing machine or
autoscrubber as known in the art. But the aperture 14 can be sized
or omitted based on requirements of a particular grinding or
polishing machine with which the abrasive pad 10 is to be used.
[0026] A coating 24 of an abrasive material is applied to the
working surface 20 of the body 12. The coating 24 is applied to the
working surface 20 by spraying or can be applied by one or more of
brushes, rollers, or submerging in the abrasive material in a
liquid or flowable form, among other ways known in the art. The
abrasive material is at least partially absorbed into the body 12
or can be superficial to the working surface. As depicted in FIG.
6, the abrasive material may at least partially coat the fibers 48
of the abrasive pad 10 and/or form globules 50 that adhere to one
or more of the fibers 48. Open spaces 52 between the fibers 48 also
allow for absorption and/or penetration of the abrasive material
into the working surface 20.
[0027] The coating 24 comprises a resin with diamonds or diamond
particles (which may be collectively referred to as diamonds)
disposed therein but embodiments of the invention are not limited
to a particular coating composition. The resin includes resins or
binders available in the art, such as for example, phenolic,
acrylic, melamine, and urea resins, or thermoplastics, and hybrid
compositions that include one or more metals like copper mixed
therein.
[0028] The diamonds are natural or industrial diamonds or particles
thereof and might be coated with one or more materials, e.g.
silver, titanium or other metals. In an embodiment, other abrasive
materials, like garnet, corundum, silicates, metals, or the like,
are used in addition to or instead of diamonds. The diamonds have
an average diameter configured to provide a desired abrasive grit
to the coating 24. In an embodiment, the diamonds have an average
diameter of about 0.1 to about 30 .mu.m (about 60,000 to about 350
grit) or between about 9 and about 15 .mu.m (about 1000 and about
700 grit) or preferably about 12 .mu.m (about 800 grit) suitable
for grinding, polishing or burnishing a concrete, terrazzo, or
stone floor. In embodiments the diamonds can be sized to provide
any desired grit ranging, for example from about 50 grit to greater
than 8500 grit.
[0029] In one embodiment, the abrasive elements 15 take the form of
low-profile circular discs 16 that are attached to the working
surface 20 of the body 12. The abrasive discs 16 are generally
cylindrical with a diameter of about 1 to about 4 inches, or about
1.5 to about 3 inches, or more preferably about 2 to about 2.5
inches and with a height of about 0.2 to about 5 millimeters or
more preferably about 0.25 to about 3 millimeters. It is to be
understood that abrasive elements 15 having dimensions outside of
the ranges specified may be utilized.
[0030] In another embodiment, as depicted in FIGS. 8 and 9, the
abrasive elements 15 take the form of low-profile similarly sized
triangular or wedge shaped abrasive elements 816 attached to the
working surface 820. Each triangular element 816 has a height of
about 1 to about 5 millimeters or more preferably about 1 to about
3 millimeters. The sides 825 of each triangular element 816 slope
slightly inward from a base 826 attached to working surface 820
toward an outer surface 827 which is supported against a surface to
be abraded thereby toward the middle of the element as the sides
extend away from working surface 820.
[0031] Each triangular element 816 is generally the shape of an
isosceles triangle with two sides of equal length 828 converging on
a point 829 remote from a third shorter side 831. The point of
convergence 829 and the midpoint 833 of the shorter side 831 align
to form a centerline (not shown) of the triangular element 816. The
sides 828 are about 3 inches long and the short side or outer edge
831 is about 0.75 inches wide. Also, side 831 has an arcuate shape
with a radius of curvature which preferably matches or closely
approximates the radius of curvature of the circumferential edge
822 of the body 812.
[0032] In another embodiment, as depicted in FIGS. 10, 11 and 12,
the abrasive elements 15 take the form of low-profile generally
trapezoid shaped abrasive elements 1016 attached to the working
surface 1020. Each trapezoidal abrasive element 1016 has a height
of about 3 millimeters measured from a base 1026 attached to
working surface 1020 to an outer surface 1027 which is supported
against a surface to be abraded thereby. Each abrasive element 1016
is generally the shape of an isosceles trapezoid except one side of
the abrasive element is curved. In one example, the curved side
1031 of abrasive element 1016 has an arcuate shape with a length of
approximately 2.5 inches and an arc length of approximately 3.5
inches. The length of the abrasive elements 1016 may preferably
range from about two to three inches. Abrasive element 1016 also
has two convergent sides 1028 that are symmetrical about a
centerline (not shown) extending through the midpoint of curved
side 1031. In the embodiment shown, the convergent sides 1028
create a taper that causes the abrasive element 1016 to narrow by
about 0.5 inches to about two inches as the element extends from
its curved side 1031 to its inner end 1029. The convergent sides
1028 may also be described as tapering toward one another as they
extend away from the curved side or outer end 1031 or as converging
toward one another as they extend toward a center of the pad 1010.
The length of abrasive element 1016 in the embodiment shown is
about 2.5 inches measured from the midpoint of the curved side 1031
to the inner end 1029. The abrasive element 1016 in the embodiment
shown is approximately 2.5 inches wide at its widest location near
curved side 1031.
[0033] The abrasive elements 1016 preferably are spaced over said
working surface in generally equally spaced radial alignment. The
tapered shape of the abrasive elements 1016 which narrow as they
extend toward the center of the pad 1010 results in a generally
uniform ratio of surface area of the pad 1010 covered by the
abrasive elements 1016 in a radial direction over the portions of
the pad 1010 covered by abrasive elements 1016.
[0034] The radius of curvature of the curved side 1031 of abrasive
element 1016 preferably matches the radius of curvature of the pad
1010 to which it is attached. However, it is foreseen that in order
to reduce the number of molds necessary to produce the abrasive
elements 1016, the abrasive elements 1016 may be formed into a
single standard size or fewer sizes than the sizes of the pads 1010
to which the abrasive elements 1016 are adapted to be attached. For
example, conventional sizes for pads 1010 may range from seven
inches up to twenty seven inches in diameter with standards sizes
of sixteen, seventeen, twenty, twenty one and twenty seven inches
in diameter. Standard diameters for floor pads range between twenty
one and twenty seven inches. The abrasive element 1016 shown in
FIGS. 10-12 is depicted as having a radius of curvature which
matches the radius of curvature of a pad 10 that is smaller than
the pad 1010 to which it is attached. For example, the pad 1010
shown could be representative of a pad having a diameter of twenty
seven inches while the radius of curvature of the abrasive element
1016 matches the radius of curvature of a pad 10 having a diameter
of twenty four inches. The abrasive element 1016 might then be used
with any pads 10 having a diameter of between twenty one to twenty
seven inches. A smaller sized abrasive element 1016 might then be
used with pads 10 having diameters of between seven and twenty one
inches and an even smaller sized abrasive element 1016 might be
used with smaller pads 10.
[0035] It is to be understood that some or all of the sides of the
abrasive elements 15 could extend generally perpendicular to the
working surface thereof such as working surface 20. It is also
understood that the sides could be radiused or a small radius or
bevel could be formed between the side and the working surface.
Also, shapes and dimensions of abrasive elements 15 other than
those specifically identified herein are foreseen. It is also
foreseen that abrasive elements of different sizes and shapes may
be mounted together on a single working surface 20.
[0036] The abrasive elements 15 are attached to the working surface
20 with one or more glues 26, adhesives, or mechanical fasteners,
such as hook-and-loop fasteners. Or the abrasive elements 15 might
be integrally molded into the working surface 20. The abrasive
elements 15 are molded or constructed from a resin with diamonds or
diamond particles (hereinafter collectively referred to as
diamonds) disposed therein but, embodiments of the invention are
not limited to a particular composition. For example, the abrasive
elements15 may comprise metal-bonded diamond particles or a base
portion that is coated with a diamond-impregnated resin. The resin
can be the same or different from that of the coating 24 and
includes resins or binders available in the art, such as for
example, phenolic, acrylic, melamine, and urea resins, or
thermoplastics, and hybrid compositions that include one or more
metals. In an embodiment, the abrasive elements 15 comprise
FLEXDOTS from Superior Surface Solutions, Inc. of Kansas City,
Mo.
[0037] The diamonds are natural or industrial diamonds or particles
thereof and might be coated with one or more materials, e.g.
silver. In an embodiment, other abrasive materials, like garnet,
corundum, silicates, metals, or the like, are used in addition to
or instead of diamonds. The diamonds/diamond particles have an
average diameter configured to provide a desired abrasive grit to
the abrasive elements 15. In an embodiment, the diamonds/particles
have an average diameter of about 15 to about 40 .mu.m (about 1100
to about 325 grit) or between about 20 and about 30 .mu.m (about
900 to about 500 grit) or preferably about 23 to about 26 .mu.m
(about 400 grit) suitable for polishing a concrete, terrazzo, or
stone floor. However, in embodiments the diamonds can be sized to
provide any desired grit; typical sizes might range from about 50
to greater than 8500 grit.
[0038] It has also been determined that varying the grit of the
diamonds in the coating 24 bonded to the pads 10 versus the grit of
the diamonds incorporated into the abrasive elements 15 results in
more efficient polishing. More specifically, the grit of the
diamonds in the coating 24 on the pad 10 is preferably greater than
the grit of the diamonds in the abrasive elements 15. Because a
higher grit indicates a smaller size, the diamonds in the coating
24 on pads 10 are preferably smaller than the diamonds in the
abrasive elements 15. In one embodiment the ratio of grits is 2 to
1 with the grit of the diamonds in the pad 10 at 800 and the grit
of the diamonds in the abrasive element 15 at 400. Another
embodiment might include a 400 grit pad 10 and a 200 grit abrasive
element 15. It is to be understood that other variations in the
ratio of grits may be used. For example, the ratio of the grit of
the particles in the pad, a first grit, versus the ratio of the
grit of the particles in the abrasive element, the second grit,
will likely range from 1.5 to 1 to 2.5 to 1 although other ratios
may also be utilized. In some applications, the grit of the diamond
particles in the pad 10 may be less than the grit of the diamond
particles in the abrasive elements 15. In such applications, the
ratio of the second grit to the first grit will also likely be 1.5
to 1 to 2.5 to 1.
[0039] A contact surface 28 of the abrasive elements 15 is also
configured with a plurality of recesses or channels 30 and plateaus
32. As depicted in FIG. 1, the channels 30 and plateaus 32 are
configured in a radially extending grid pattern or, in another
embodiment depicted in FIG. 3, channels and plateaus of abrasive
discs 316 on an abrasive pad 310 are configured in a repeating
linear pattern. In yet another embodiment, as depicted in FIG. 10,
channels 1030 are arranged in a crossing arcuate grid pattern
forming a plurality of quadrilateral plateaus 1032. It is
understood that any pattern or configuration is useable in
embodiments of the invention. It is also understood that the
channels 30 may be any depth or of differing depths in the same
abrasive element 15. The channels 30 may aid polishing by the
plateaus 32 guiding materials produced by or used for polishing
away from the plateaus 32. Such may decrease or eliminate
scratching of the surface being worked on by those materials being
trapped between the plateaus 32 and the surface and may reduce
gumming of the abrasive elements 15. The materials include, for
example, particles abraded from the surface being worked on, dirt
or dust on the surface, particles from the abrasive elements 15,
and fluids or polishing agents applied to the surface. In an
embodiment, the channels 30 might also increase the flexibility of
the abrasive elements 15 to enable better conformance of the
abrasive elements 15 to uneven features of the surface being worked
on.
[0040] As depicted in FIG. 1, the abrasive discs 16 are evenly
spaced on the working surface 20 near the circumferential edge 22
of the body 12. In an embodiment, the abrasive discs 16 are all
disposed within the outer third of the working surface 20. In
another embodiment, depicted in FIG. 3, the abrasive discs 316 are
disposed on a working surface 320 in a staggered arrangement across
the entire working surface 320. It is to be understood that the
arrangements of the abrasive discs 16 and 316 depicted in FIGS. 1
and 3 are exemplary and not limiting. Other arrangements of the
abrasive elements 15 can be used in embodiments of the invention
without departing from the scope described herein.
[0041] As depicted in FIGS. 8, 9, 10, 11 and 12, if the abrasive
elements 15 are in the form of wedges 816 or trapezoids 1016, the
abrasive elements are preferably radially disposed about the center
of central aperture 814 or 1014. Each abrasive element 816 or 1016
is oriented such that the center of central aperture 814 or 1014
aligns with the centerline of the abrasive element. Each abrasive
element 816 or 1014 is located at the periphery of body 812 or
1012. Sides 831 or 1031 for each abrasive element align with the
outermost circumferential surface 835 or 1035 of the body. A
benefit of orienting the abrasive elements 816 and 1016 in this
manner is that the widest portion, and consequently the greatest
amount of surface area, of each abrasive element is at the
periphery of the body. This ensures that a surface being treated by
pad 810 or 1010 receives treatment from the abrasive elements even
if the surface only contacts the periphery of the pad. Furthermore,
when compared to disc shaped abrasive elements, using abrasive
elements 816 and 1016 in the configurations disclosed herein
results in treated surfaces receiving a more consistent ratio of
pad working surface treatment to abrasive element treatment as the
pad moves over the surface.
[0042] The abrasive pad 10 also includes a peripheral reinforcement
34 along at least a portion of the circumferential edge 22. The
reinforcement 34 comprises one or more of a rubber, resin, latex,
mastic, glue, adhesive, plastic, paper, wood, or metal that is
applied or coupled to the circumferential edge 22. The
reinforcement may comprise, for example, a polyvinyl acetate glue
with a plasticizer added to result in a cured product that is more
flexible and resilient. The reinforcement 34 at least partially
reinforces the body 12 at the circumferential edge 22 against
compression. The reinforcement 34 also allows at least partial
flexibility of the abrasive pad 10 near the circumferential edge 22
to allow conformance to uneven features of the surface being worked
on. The reinforcement 34 is applied to the entire circumferential
edge 22 or can be applied only to sections of the circumferential
edge 22 proximate to one or more of the abrasive elements 15.
[0043] It is foreseen that the abrasive elements 816 and 1016 may
be used with or without a peripheral reinforcement 834 or 1034
(FIGS. 8, 9, 10, 11 and 12 show the elements being used with
peripheral reinforcement). The peripheral placement of abrasive
elements 816 and 1016 as described above allow the elements to make
sufficient contact with the surface being treated without the need
for peripheral reinforcement.
[0044] In another embodiment depicted in FIG. 7, the reinforcement
734 on an abrasive pad 710 can penetrate between the fibers 748 and
at least partially into the abrasive pad 710. In an embodiment, the
penetration of the reinforcement 734 into the abrasive pad 710 is
not uniform. The reinforcement 734 penetrates a greater distance
into the abrasive pad 710 near the middle of the thickness thereof
than at the non-working side 718 and the working surface 720.
However, the penetration of the reinforcement 734 can be configured
in other ways including no penetration or uniform penetration,
among others.
[0045] One or more layers of similar or dissimilar materials can be
applied to the circumferential edge 22 to form the reinforcement
34. In an embodiment, the reinforcement 34 is a rubber material
such as PLIOBOND from Ashland, Inc. of Covington, Ky.
[0046] With reference now to FIG. 4, operation of an abrasive pad
410 of the prior art is described. As depicted in FIG. 4, the prior
art abrasive pad 410 includes an abrasive element 416 affixed near
a circumferential edge 422 of a working surface 420 thereof. The
abrasive pad 410 is also coupled to a rigid or flexible driver 436
of a rotary grinding/polishing machine 438 as is known in the art.
The abrasive pad 410 and abrasive element 416 may comprise similar
materials and configurations as described above for the body 12 of
the abrasive pad 10 and the abrasive elements 16. The abrasive pad
410 does not include the coating 24 or the reinforcement 34.
[0047] In use, the abrasive pad 410 is unable to maintain the
abrasive elements 416 disposed adjacent to the circumferential edge
422 parallel to and in full contact with a surface 440 being worked
on. The body 412 of the abrasive pad 410 in an area 442 that is
near the circumferential edge 422 and between the abrasive element
416 and the circumferential edge 422 is compressed by forces
applied during grinding/polishing. The forces include one or a
combination of pressure applied by the grinding/polishing machine
438 toward the surface 440 and rotational forces resulting from
rotating the abrasive pad 410 by the grinding/polishing machine
438. The body 412 in the area 442 is weaker than the remainder of
the body 412 at least because of the free, unsupported
circumferential edge 422; areas that are radially inward from the
circumferential edge 422 are supported by the surrounding material
of the body 412 and do not compress to the extent found in the area
442.
[0048] The abrasive element 416 is thus not equally supported
across its width by the body 412, e.g. a greater force toward the
surface 440 is applied near a radially inward edge 444 than is
applied near a radially outward edge 446. As such, the radially
outward edge 446 of the abrasive element 416 tends to lift away
from the surface 440. This leads to uneven wear on the abrasive
element 416, less grinding/polishing action being applied to the
surface 440, and slower overall performance of the abrasive pad
410.
[0049] Turning now to FIG. 5, use of the abrasive pad 10 is
described in accordance with an embodiment of the invention. The
abrasive pad 10 is coupled to a rigid or flexible driver 36 of a
rotary grinding/polishing machine 38 as is known in the art. Upon
application of the working surface 20 of the abrasive pad 10 to a
surface 40 to be ground/polished, the abrasive disc 16 at least
partially compress overlying portions of the body 12 and at least
partially recess into the body 12. In an embodiment, the abrasive
elements 15 recess into the body 12 a sufficient distance to place
both the contact surfaces 28 of the abrasive elements 15 and the
working surface 20 of the abrasive pad 10 in contact with the
surface 40 to be ground/polished.
[0050] The peripheral reinforcement 34 provides additional support
for the area 42 between and/or proximate to the circumferential
edge 22 and the abrasive elements 15. The contact surfaces 28 of
the abrasive elements 15 are thus maintained parallel to and in
contact with surface 40 during grinding/polishing. The
reinforcement 34 has sufficient rigidity to substantially resist
compression of the body 12 as described above and is sufficiently
resilient to allow flexure of the body 12 when encountering
obstructions or uneven features on the surface 40.
[0051] In operation, the simultaneous contact of the abrasive
elements 15 and the coating 24 on the working surface 20 of the
body 12 with the surface 40 provides synergistic benefits. For
example, an abrasive element 15 with a lower grit can be paired
with a coating 24 on the abrasive pad 10 that has a finer/higher
grit to achieve a finish on the surface 40 comparable to that
achievable through a number of separate steps using a plurality of
pads, the finest of which having a grit similar to that of the
coating 24.
[0052] And the abrasive elements 15 and coating 24 can be
configured to simultaneously employ the benefits of each form of
abrasive. For example, in concrete grinding/polishing, abrasive
elements like the abrasive elements 15 do not substantially produce
an effect known in the art as orange peal in the surface finish
but, abrasive elements work relatively slowly. In contrast, pads
with abrasive coatings like the abrasive pad 10 and coating 24,
typically produce orange peal in the surface finish but work more
quickly than abrasive elements. And larger, coarser grits tend to
wear out more quickly when used as a coating on a pad than when
applied via abrasive elements.
[0053] As such, continuing the above example, the lower grit
abrasive element 15 provides slower but deeper cutting/polishing of
the surface 40 while also substantially eliminating or reducing the
appearance of orange peal from the surface 40. The higher grit
coating 24 provides faster, shallower, and finer polishing of the
surface 40. And the life of the coating 24 is extended because
finer grit particles are used in the coating 24 and lower grit
particles are placed in the longer lasting abrasive elements 15. In
another embodiment, the abrasive element 15 has a higher grit while
the coating 24 has a lower, coarser grit. In this case the finer
grit particles in the abrasive element 15 refine orange peel
created by the coarser grit particles in the coating 24. Such an
arrangement may be beneficial for softer surfaces 40.
[0054] In one example, the abrasive pad 10 has an 800 grit coating
24 configured for burnishing a concrete surface 40 along with 400
grit abrasive elements 15 configured for polishing the surface 40.
The abrasive elements 15 thus provide deeper cutting but slower
polishing of the surface 40 while the coating 24 provides faster,
shallower, finer burnishing of the surface 40. The resulting finish
on the surface 40 is similar to a surface that is at least first
polished with a 400 grit abrasive and then burnished with an 800
grit abrasive. But the resulting finish on the surface 40 is
obtained in a single step rather than through two or more separate
steps. And the time necessary for completing the single step is
less than that required to complete the two or more separate steps.
Further, by using the abrasive elements 15 and the coating 24
simultaneously, orange peal that might result from burnishing with
the coating 24 is reduced or eliminated by the abrasive elements
15. As such, the resulting surface finish achieved by the abrasive
pad 10 might exceed that achievable with separate polishing and
burnishing pads without an additional step to remove the orange
peal from the surface 40.
[0055] Many different arrangements of the various components
depicted, as well as components not shown, are possible without
departing from the scope of the claims below. Embodiments of the
technology have been described with the intent to be illustrative
rather than restrictive. Alternative embodiments will become
apparent to readers of this disclosure after and because of reading
it. Alternative means of implementing the aforementioned can be
completed without departing from the scope of the claims below.
Certain features and subcombinations are of utility and may be
employed without reference to other features and subcombinations
and are contemplated within the scope of the claims.
* * * * *