U.S. patent application number 11/864170 was filed with the patent office on 2008-04-03 for dust vacuuming abrasive tool.
This patent application is currently assigned to 3M Innovative Properties Company. Invention is credited to HITOSHI OKA, SATORU TAKINAMI.
Application Number | 20080081546 11/864170 |
Document ID | / |
Family ID | 39261666 |
Filed Date | 2008-04-03 |
United States Patent
Application |
20080081546 |
Kind Code |
A1 |
TAKINAMI; SATORU ; et
al. |
April 3, 2008 |
DUST VACUUMING ABRASIVE TOOL
Abstract
The present disclosure is directed to a dust vacuuming abrasive
tool comprising an abrasive sheet material having an abrasive
surface, a back surface and 20 or more perforations; and a backup
pad having a support surface, a back surface and 20 or more
perforations, or a plurality of perforations and also having, in
the supporting surface. The configuration of the abrasive sheet and
back-up pad eliminate the need to align perforations in the
abrasive sheet and back-up pad.
Inventors: |
TAKINAMI; SATORU; (Tokyo,
JP) ; OKA; HITOSHI; (Tokyo, JP) |
Correspondence
Address: |
3M INNOVATIVE PROPERTIES COMPANY
PO BOX 33427
ST. PAUL
MN
55133-3427
US
|
Assignee: |
3M Innovative Properties
Company
|
Family ID: |
39261666 |
Appl. No.: |
11/864170 |
Filed: |
September 28, 2007 |
Current U.S.
Class: |
451/527 |
Current CPC
Class: |
B24B 55/102 20130101;
B24D 11/00 20130101 |
Class at
Publication: |
451/527 |
International
Class: |
B24D 11/00 20060101
B24D011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 29, 2006 |
JP |
2006-268351 |
Claims
1. A dust vacuuming abrasive tool comprising: a) an abrasive sheet
material having an abrasive surface, a back surface and 20 or more
perforations; and b) a backup pad having a support surface, a back
surface and i) 20 or more perforations, or ii) a plurality of
perforations and also having, in the supporting surface, channels
which interconnect the perforations and extend along lines
connecting the 20 or more perforations of the abrasive sheet
material; the back surface of the abrasive sheet material being
fixed detachably on the support surface of the backup pad wherein
the 20 or more perforations of the abrasive sheet material are
approximately adjacent the backup pad perforations and are arranged
in a lattice of equally spaced equilateral triangles, wherein the
diameter of the abrasive sheet material perforations are 2 to 8 mm,
wherein the distance between two adjacent perforations is not
greater than 1.5 times the diameter of the perforations, and
wherein the diameter of the backup pad perforations is 80 to 120%
of the diameter of the abrasive sheet material perforations.
2. A dust vacuuming abrasive tool comprising: a) an abrasive sheet
material having an abrasive surface, a back surface and 20 or more
perforations; b) an intermediate pad having a supporting surface, a
back surface and i) 20 or more perforations, or ii) a plurality of
perforations and also having, in the supporting surface and/or the
back surface, channels which interconnect the perforations and
extend along lines connecting the 20 or more perforations of the
abrasive sheet material, and c) a backup pad having a supporting
surface, a back surface and a plurality of perforations; the back
surface of the abrasive sheet material being fixed detachably on
the supporting surface of the intermediate pad and the back surface
of the intermediate pad being fixed detachably on the supporting
surface of the backup pad; wherein the 20 or more perforations of
the abrasive sheet material are approximately adjacent the
intermediate pad perforations and are arranged in a lattice of
equally spaced equilateral triangles; wherein the diameters of the
perforations of the abrasive sheet material is 2 to 8 mm, wherein
the distance between two adjacent perforations is not greater than
1.5 times the diameters of the perforations, and wherein the
diameter of the perforations of the intermediate pad is 80 to 120%
of the diameter of the perforations of the abrasive sheet
material.
3. The dust vacuuming abrasive tool according to claim 2, wherein
the backup pad is: i) a backup pad having a supporting surface, a
back surface and 20 or more perforations, wherein the 20 or more
perforations are approximately adjacent, and the diameter is 80 to
120% of, the abrasive sheet material perforations, or ii) a backup
pad having a supporting surface, a back surface and a plurality of
perforations and also having, in the supporting surface, channels
which interconnect the perforations and extend along lines
connecting the 20 or more perforations of the abrasive sheet
material.
4. The dust vacuuming abrasive tool according to claims 1, wherein
the perforations of the abrasive sheet material are equally sized
circles.
Description
CROSS-REFERENCE RELATED APPLICATIONS
[0001] This application claims priority from Japanese Patent
Application No. 2006-268351, filed on Sep. 29, 2006.
TECHNICAL FIELD
[0002] The present invention relates to a dust vacuuming abrasive
tool having an abrasive sheet material with perforations, and a
supporting pad with perforations and a ventilative member, for
vacuuming dust during abrading work.
BACKGROUND ART
[0003] Painting coat, clear coat, putty filler, primer and the like
are abraded in automobile repairing work and the like. When
painting coat, clear coat, putty filler, primer or the like is
abraded, a large amount of abraded dust, or swarf, is created. This
swarf has to be removed otherwise the surface of the abrasive
material would become clogged, resulting in reduced abrading
efficiency. Therefore, conventional dust vacuuming abrasive tools
having perforations in an abrasive surface are well known.
[0004] Such abrasive tools are generally formed of an abrasive
sheet material (abrasive cloth or the like) and a pad for
supporting the abrasive material, sometimes called a back-up pad.
In an exemplary pad, about 6 or 7 perforations for vacuuming dust
having a diameter of approximately 10 mm are formed at
predetermined positions in the abrasive material and in the pad.
Thus, the abrasive sheet material is mounted on the surface for
attaching an abrasive material of the pad, so that the perforations
overlap, and perforations which penetrate through to the rear side
are formed in the abrasive surface of the abrasive tool.
[0005] Abrading work is carried out by attaching a sander having a
vacuuming function to the rear surface of the abrasive tool, and
abraded swarf is vacuumed through the perforations in the abrasive
surface and discharged.
[0006] When an abrasive material is mounted on the pad, the work of
attaching the abrasive material while visually confirming the
alignment of the perforations in the pad and in the abrasive
material is troublesome. In the case where the perforations in the
abrasive material do not align with the perforations in the pad,
the number of perforations in the abrasive surface is effectively
reduced, and therefore, sufficient dust vacuuming performance
cannot be obtained. Therefore, when the type of abrasive material
is changed, and the alignment of the perforations, or the format of
the perforations changes, it also may be necessary to change the
back-up pad accordingly, which is time-consuming and
inefficient.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 shows a cross sectional diagram showing the structure
(portion) of an abrasive sheet material having perforations.
[0008] FIG. 2 shows a diagram showing the abrasive surface of an
abrasive sheet material used in the present invention.
[0009] FIG. 3 shows a cross sectional diagram showing one example
of a backup pad suitable for use in the present invention.
[0010] FIG. 4 shows a diagram showing the support surface of a
backup pad suitable for use in the present invention.
[0011] FIG. 5 shows a diagram showing the support surface of a
backup pad suitable for use in the present invention.
[0012] FIG. 6 shows a cross sectional diagram showing one example
of an intermediate pad suitable for use in the present
invention.
[0013] FIG. 7 shows a diagram showing another example of the
support surface or back surface of an intermediate pad suitable for
use in the present invention.
[0014] FIG. 8 shows a diagram showing another example of the
support surface or back surface of an intermediate pad suitable for
use in the present invention.
[0015] FIG. 9 shows a diagram showing another example of the
support surface or back surface of an intermediate pad suitable for
use in the present invention.
[0016] FIG. 10 shows a diagram showing how the condition of overlap
of perforations changes with the angle at which the perforated
structures are shifted.
DISCLOSURE OF THE INVENTION
[0017] The present disclosure is provided in order to solve the
above-described problems with the prior art, and is to make it
unnecessary to align the perforations of an abrasive sheet material
with those of the support pad, and to reduce the labor for
replacing abrasive materials.
[0018] The present disclosure provides a dust vacuuming abrasive
tool comprising: [0019] a) an abrasive sheet material having an
abrasive surface, a back surface and 20 or more perforations; and
[0020] b) a backup pad having a support surface, a back surface and
[0021] i) 20 or more perforations, or [0022] ii) a plurality of
perforations and also having, in the supporting surface, channels
which interconnect the perforations and extend along lines
connecting the 20 or more perforations of the abrasive sheet
material; [0023] the back surface of the abrasive sheet material
being fixed detachably on the support surface of the backup pad
[0024] wherein the 20 or more perforations of the abrasive sheet
material are approximately adjacent the backup pad perforations and
are arranged in a lattice of equally spaced equilateral triangles,
[0025] wherein the diameter of the abrasive sheet material
perforations are 2 to 8 mm, [0026] wherein the distance between two
adjacent perforations is not greater than 1.5 times the diameter of
the perforations, and [0027] wherein the diameter of the backup pad
perforations is 80 to 120% of the diameter of the abrasive sheet
material perforations.
[0028] Furthermore, the present disclosure provides a dust
vacuuming abrasive tool comprising: [0029] a) an abrasive sheet
material having an abrasive surface, a back surface and 20 or more
perforations; [0030] b) an intermediate pad having a supporting
surface, a back surface and [0031] i) 20 or more perforations, or
[0032] ii) a plurality of perforations and also having, in the
supporting surface and/or the back surface, channels which
interconnect the perforations and extend along lines connecting the
20 or more perforations of the abrasive sheet material, and [0033]
c) a backup pad having a supporting surface, a back surface and a
plurality of perforations; [0034] the back surface of the abrasive
sheet material being fixed detachably on the supporting surface of
the intermediate pad and the back surface of the intermediate pad
being fixed detachably on the supporting surface of the backup pad;
[0035] wherein the 20 or more perforations of the abrasive sheet
material are approximately adjacent the intermediate pad
perforations and are arranged in a lattice of equally spaced
equilateral triangles; [0036] wherein the diameters of the
perforations of the abrasive sheet material is 2 to 8 mm, wherein
the distance between two adjacent perforations is not greater than
1.5 times the diameters of the perforations, and [0037] wherein the
diameter of the perforations of the intermediate pad is 80 to 120%
of the diameter of the perforations of the abrasive sheet
material
[0038] With the abrasive tools described herein, it becomes
possible to mount an abrasive sheet material at an arbitrary angle
to a pad, thereby reducing the problem of aligning the perforations
when an abrasive sheet material is attached to a pad.
[0039] The dust vacuuming abrasive tool of the present disclosure
comprises a combination of an abrasive sheet material which has 20
or more dust vacuuming perforations arranged in a predetermined
size and formation, and an intermediate pad and/or backup pad
having a plurality of dust vacuuming perforations. Hereinafter, a
plurality of dust vacuuming perforations arranged in a
predetermined size and formation are sometimes referred to
collectively as a perforated structure.
[0040] In the present disclosure, "effective perforations" means
the portions where perforations in an abrasive material and
perforations in a pad overlap. That is to say, "effective
perforations in the abrasive surface" are passageways which
penetrate through the abrasive surface of the abrasive tool to the
rear surface, and have the function of vacuuming abraded swarf
through the sander. In addition, "perforations" as used herein,
means through holes, excluding recesses.
Abrasive Sheet Material
[0041] FIG. 1 is a cross sectional diagram showing the structure
(portion) of an abrasive sheet material having dust vacuuming
perforations. The surface of a base 11 is coated with a binder 12,
and abrasive particles 13 are adhered to the base 11 with binder
12. A surface of the base on which abrasive particles are provided
is an abrasive surface, and a surface on which no abrasive
particles are provided is a back surface. An attaching member is,
if needed, provided on the back surface of the abrasive material in
sheet form. The abrasive material is provided with dust vacuuming
perforations 14, 14' penetrating from the abrasive surface to the
back surface.
[0042] It is preferable for any protruding edge of the perforations
on the abrasive surface side be removed, otherwise there is a risk
that the surface to be abraded may be scratched.
[0043] The perforations may be formed by carrying out a punching
process on an abrasive material in sheet form, or alternatively,
laser converted. When an abrasive material is punched, it is
preferable for the blade to enter in the direction from the
abrasive surface to the rear surface of the base. As a result it
prevents the perforated edge from protruding from the abrasive
surface. In addition, the perforations may be formed by punching
out the base in advance.
[0044] The base may be any material which is conventionally used as
a base for an abrasive material in sheet form. For example, a
polymer film, a woven cloth, a non-woven cloth, a sheet of paper,
an impregnated sheet of paper, a polymer coated sheet of paper, an
elastomer in foam form or the like can be used. Other materials
suitable for bases are oil or resin impregnated sheets of paper,
polymer coated sheets of paper, polyester films, such as
polyethylene terephthalate, and such sheets of paper and films on
which a metal has been vapor deposited. The thickness of the base
is generally 12 micrometers (.mu.m) to 5000 .mu.m, and in one
embodiment 38 .mu.m to 3000 .mu.m.
[0045] Abrasive particles are adhered to the surface of the base
with a binder. As for the binder, binders which can secure
sufficient adhesive strength and are conventionally used for an
abrasive material for repairing automobiles are used. Phenol resin,
epoxy resin, polyester resin, urethane resin, acryl resin, urea
resin and the like can be cited as examples.
[0046] As for the abrasive particles, abrasive particles that can
be used for an abrasive material for repairing automobiles are
used. As for the material thereof, for example, aluminum oxide,
cerium oxide, silicon carbide, diamond, alumina oxide, including
melt alumina, ceramic alumina (including sol-gel alumina) and the
like can be cited. In addition, the abrasive particles may be fine
particles made of plastic, such as polymethacrylate ester,
polystyrene, polyolefin and the like. As for the dimensions of the
abrasive particles, the average particle diameter is generally
approximately 500 .mu.m to about 0.45 .mu.m. In some embodiments,
the average particle diameter is about 500 .mu.m (JIS #36) to about
0.45 .mu.m (JIS #20000), and preferably, the average particle
diameter is about 5 .mu.m (JIS #2500) to about 300 .mu.m (JIS
#60).
[0047] The abrasive sheet material may be made from a coated
abrasive, which is subsequently perforated. Alternatively, the
backing material may be perforated, after which it may be coated
with a binder and abrasive particles, then cured according to
established methods known to those of ordinary skill in the
art.
[0048] FIG. 2 is a diagram showing the abrasive surface of an
abrasive sheet material used in the present disclosure. This
abrasive material 20 in sheet form is provided with 61 perforations
24, 24' on the abrasive surface. The number of perforations 24 is
at least about 20 in one embodiment, from about 20 to 150 in a
further embodiment, and more preferably from about 30 to 100 in
another embodiment.
[0049] Arrangement of perforations 24, 24' is configured to be
contiguous lattice where the centers of three adjacent perforations
form an equilateral triangle. The distance between adjacent
perforations, which are located at vertices of an equilateral
triangle, is not greater than about 1.5 times, and preferably from
0.5 to 1.5 times the diameters of the perforations. If the distance
between adjacent perforations is greater than 1.5 times the
diameters of the perforations, the perforations of the abrasive
sheet material and those of the backup pad, or those the
intermediate pad, may not be adequately aligned when such pads or
abrasive sheet materials are moved about their respective axis of
rotation. Consequently, the dust vacuuming efficiency of the tool
is reduced.
[0050] The diameter of the perforations 24 is about 2 to about 8 mm
in one embodiment, and about 3 to about 7 mm in a further
embodiment. If the diameter of the perforations is too small,
abraded swarf will tend to clog the hole, whereas a too large a
diameter, will reduce the vacuuming force per perforation.
[0051] It is not always necessary for the perforations to be
uniformly arranged throughout the entire abrasive surface. This is
because the amount of swarf generated is not uniform throughout the
abrasive surface. For example, since the abrasive power is weak in
the center of the axis of rotation of the abrasive surface and the
amount of swarf is small, the dust vacuuming performance does not
decrease even if some dust vacuuming perforations are omitted. For
some applications, it may be desirable to enhance the abrading
power in a peripheral area of an abrasive surface by forming an
area having fewer, or even no perforations, in the peripheral
area.
[0052] An appropriate form in a plan view and the dimensions of the
abrasive sheet material may be determined in accordance with the
application. Disc form, for example, is generally used. This is
also true for the described pad below.
Backup Pad
[0053] An abrasive sheet material is poor in self-supporting
ability and therefore it is difficult to apply adequate abrasive
pressure to a surface to be sanded. Therefore, the abrasive sheet
material is attached to a sufficiently hard backup pad in order to
apply adequate abrasive pressure to the surface to be sanded.
[0054] The pad includes several kinds, such as a backup pad and an
intermediate pad, depending on applications. The backup pad is a
pad which is used while being mounted directly to a sander. FIG. 3
is a cross sectional diagram showing one example of a backup pad
suitable for use in the present invention. This backup pad 30 has a
structure where an elastic resin layer 32 is disposed on a rigid
material layer 31. The exposed surface of the elastic resin layer
32 side is a supporting surface. The exposed surface of the rigid
material layer 31 side is a back surface. The supporting surface
may be provided with an attachment member, if needed. The back
surface is provided with means for mounting the backup pad to a
sander, for example, a bolt 33. Moreover, the backup pad has
perforations 34, 34' penetrating from the support surface to the
back surface.
[0055] FIG. 4 is a diagram showing the support surface of a backup
pad suitable for use in one embodiment of the present invention.
This backup pad 40 has many perforations 44, 44' in its support
surface. The number of perforations 44 is at least about 20, and
from about 20 to 150 in one embodiment, and from about 30 to 100 in
a further embodiment.
[0056] The arrangement of the perforations 44 is almost the same as
that of the abrasive sheet material in sheet form. Namely, the size
of an equilateral triangle formed by the centers of three adjacent
perforations is the same between the abrasive sheet material and
the backup pad. However, it is not necessary to make the number of
the perforations of the backup pad exactly equal to that of the
abrasive sheet material. This is because, as mentioned above, it is
not always necessary to arrange perforations uniformly throughout
the support surface and the arrangement may be changed depending
upon required performance or applications.
[0057] The diameter of the perforations of the backup pad is 80 to
120% in one embodiment, and 90 to 110% in a further embodiment, of
the diameter of the perforations of the abrasive material in sheet
form. If the ratio is less than 80%, the dust vacuum efficiency
will fall. On the other hand, if it is over 120%, the support
provided by the backup pad adjacent the abrasive sheet material
perforations will adversely affect the abrasive performance.
[0058] In the support surface of the backup pad, channels may be
formed along lines connecting all or part of the perforations 44,
44'. Such channels, will efficiently guide the swarf that has
passed through the abrasive sheet perforations to the perforations
44, 44' of the backup pad.
[0059] The width of the channels is from about 1 to 8 mm, and in
some embodiments from about 2 to 7 mm. If the channels are too
narrow, the swarf will not be effectively guided toward the
perforations in the backup pad. If the channels are too wide, the
backup pad may not hold the abrasive sheet material effectively
during the sanding operation. The depth of the channels is from
about 0.5 to 5.0 mm, from about 1.0 to 3.0 mm. If the channels are
too shallow, the guiding dust-vacuuming property will fail to be
exerted sufficiently, because each small swarf is condensed
(agglutinated) into larger lamp (mass). On the other hand if the
channels are too deep, insufficient vacuum may cause the swarf to
become trapped in the channels, because each swarf is piled up
(accumulated) on the bottom of the channels as sediment
(deposit).
[0060] FIG. 5 is a diagram showing the support surface of a backup
pad suitable for use in the present invention. This backup pad 50
has seven perforations 54, 54' in its support surface. The number
of perforations 54 is not particularly limited and may be
appropriately determined, for example, within the range of from
about 3 to 70 or from about 5 to 19. The diameter and arrangement
of perforations 54 are also not particularly restricted and may be
determined by taking into consideration the supporting function and
dust vacuuming function of the backup pad.
[0061] Moreover, the supporting surface of this backup pad 50 is
provided with channels 55. The channels 55 are arranged along lines
connecting the 20 or more perforations of the abrasive sheet
material. The channels 55 interconnect dust vacuuming perforations
54, 54'. Swarf which has passed through perforations 24, 24' of the
abrasive sheet material travels along the channels 55 and is guided
to dust vacuuming perforations 54, 54' of the backup pad.
[0062] The channels in the supporting surface of the backup pad
need not be arranged along all the lines connecting the 20 or more
dust vacuuming opening of the abrasive sheet material and may be
arranged partly along the lines.
Intermediate Pad
[0063] The intermediate pad means a pad which is used to adjust the
hardness or compliancy of the backup according to the needs of the
sanding operation. It is mounted between the abrasive sheet
material and the backup pad. For example, in the case of abrading
an object with a curved surface, if a surface supporting the
abrasive sheet material is made of elastic resin, the surface is so
hard that the abrasive material does not come into contact
uniformly with the entire curved surface of the object. As a
result, uneven abrasion causes a problem in that it is impossible
to abrade the entire surface uniformly. As a solution of this
problem, a sponge pad is mounted between an abrasive sheet material
and a backup pad to reduce the hardness of the supporting surface.
FIG. 6 is a cross sectional diagram showing one example of an
intermediate pad suitable for use in the present invention. This
intermediate pad 60 is composed of a sponge layer 61. One exposed
surface is a supporting surface and the other exposed surface is a
back surface. The supporting surface and the back surface may be
provided with an attachment member, if needed. The intermediate pad
has perforations 64, 64' penetrating from the support surface to
the back surface. The number, arrangement and size of perforations
may be determined like those of the backup pad. For example, the
opening structure shown in FIG. 2 may be used as arrangement of
perforations.
[0064] FIG. 7 is a diagram showing another example of the
supporting surface or back surface of an intermediate pad suitable
for use in the present invention. This intermediate pad 70 has
seven perforations 74, 74' in its supporting surface. The number of
the perforations 74 is not particularly limited and may be
appropriately determined, for example, within the range of from
about 3 to 70 or from about 5 to 19. The diameter and arrangement
of perforations 74 are also not particularly restricted and may be
determined by taking into consideration the supporting function and
dust vacuuming function of the intermediate pad.
[0065] Moreover, the supporting surface and/or the back surface of
this intermediate pad 70 is provided with channels 75. The channels
75 are arranged along lines connecting the 20 or more dust
vacuuming perforations of the abrasive material in sheet form. The
channels 75 cross the perforations 74, 74' to interconnect them.
Swarf which has passed through perforations 24, 24' of the abrasive
sheet material travels along the channels 75 and is guided to
perforations 74, 74' of the intermediate pad.
[0066] The channels in the support surface or back surface of the
intermediate pad need not be arranged along all the lines
connecting the 20 or more perforations of the abrasive sheet
material and may be arranged partly along the lines. The width and
depth of the channels may be determined like those of the backup
pad.
[0067] FIG. 8 is a diagram showing another example of the support
surface or back surface of an intermediate pad for use in the
present invention. This intermediate pad 80 has channels 85 in
addition to 61 perforations 84, 84'. The channels 85 are arranged
along lines interconnecting all the perforations 84, 84'.
[0068] FIG. 9 is a diagram showing another example of the
supporting surface or back surface of an intermediate pad for use
in the present invention. The channels in the supporting surface or
back surface are arranged along lines connecting the dust vacuuming
perforations 94, 94' in a series of concentric loops.
Dust Vacuuming Abrasive Tool
[0069] The back surface of an abrasive sheet material as described
above is removeably attached to the supporting surface of a pad,
and thereby, a dust vacuuming abrasive tool of the present
invention is obtained. When an intermediate pad is used as the pad,
the back surface of the intermediate pad is further removeably
attached to the supporting surface of a backup pad, and thereby, a
dust vacuuming abrasive tool of the present invention is obtained.
A conventional attachment member may be used. Examples of
preferable members include 2-part hook and loop mechanical
fasteners and adhesives. In the case where a 2-part hook and loop
mechanical fastener is used, a clearance is created between the
abrasive material and the backup pad, and this clearance functions
as a channel for vacuuming abraded swarf, and therefore, the
efficiency of dust vacuum can further be increased. The hook part
of the mechanical fastener may be attached to either the rear
surface of the abrasive sheet material and the loop part of the
mechanical fastener attached to the support surface of the backup
pad, or vice versa. The height of the clearance may be adjusted
using the height of the loops, and it is not smaller than about 0.5
mm, preferably not smaller than about 1 mm to 2 mm, in order to
make it function as a channel for vacuuming dust.
[0070] In the dust vacuuming abrasive tool according to the present
embodiment, it is not necessary to match the positions of
perforations of the backup pad or intermediate pad and the abrasive
sheet material when attaching the abrasive sheet material to the
intermediate pad or backup pad. That is to say, whichever the
direction in which the abrasive sheet material or the pad is
placed, the area of the effective perforations in the abrasive
surface can be secured so as to have not less than a certain value,
and the dust vacuuming performance of the abrasive surface is
maintained.
[0071] Though the present invention is accurately described using
the following examples, the present invention is not limited to
these.
EXAMPLES
Example 1
[0072] A nylon pile loop material of a mechanical fastener was
attached to the back surface of an abrasive material "Disc Unicut
P400" having a diameter of 125 mm, made by Sumitomo 3M Ltd.
Perforations were formed in the abrasive material to form an
opening structure shown in FIG. 2. Thus, an abrasive sheet material
was obtained. The total number of circular perforations was 61, all
having a diameter of 5.0 millimeters (mm). The centers of three
adjacent perforations form an equilateral triangle of length. The
distance between adjacent perforations is 6.8 mm.
[0073] A 10 mm-thick sponge sheet was punched into a circle 125 mm
in diameter. A hook material of a mechanical fastener was attached
to the supporting surface of the resultant sponge disc and a loop
material of the mechanical fastener was attached to the back
surface. Perforations were formed in the disc material to form an
opening structure shown in FIG. 2. Thus, an intermediate pad was
obtained. The 5.5 mm diameter perforations were the in the same
arrangement as the abrasive sheet material. The diameter of the
intermediate pad perforations were 110% of the diameter of the
abrasive sheet material perforations.
[0074] A hook material of a mechanical fastener was attached to the
supporting surface of a solid (unperforated) backup pad "Sander Pad
(without perforations)" having a diameter of 125 mm, made by
Shinano Inc. Perforations were formed in this pad material to form
an opening structure shown in FIG. 2. Thus, a backup pad was
obtained. The 5.5 mm diameter perforations were the in the same
arrangement as the abrasive sheet material. The diameter of the
backup pad perforations were 110% of the diameter of the abrasive
sheet material perforations.
[0075] The back surface of the abrasive sheet material was fixed to
the support surface of the intermediate pad and the back surface of
the intermediate pad was fixed to the support surface of the backup
pad. Thus, a dust vacuuming abrasive tool was obtained. The
clearance between the back surface and the support surface was
adjusted to 2 mm.
[0076] When the two opening structures shown in FIG. 2 are
overlapped, the degree of overlap, or alignment, of dust vacuuming
perforations changes with the angle at which the opening structures
are shifted about the axis of rotation. FIG. 10 is a diagram
showing how the degree of overlap of perforations changes with the
angle at which the perforated structures are shifted. In the
diagram, one of perforations which at least partly overlap together
is shaded. When the angle is changed by 5.degree. over the range
0.degree. to 30.degree., the number of overlapping perforations
changes, as shown in the diagram. The number of dust vacuuming
perforations overlapping becomes maximum at a shift angle of
0.degree. and it becomes minimum at a shift angle of
10.degree..
[0077] Sanding test performed under the conditions shown Table 1
while changing the shift angle between an abrasive sheet material
and an intermediate pad and the shift angle between an intermediate
pad and a backup pad in a dust vacuuming abrasive tool. In the
test, the ratio of the discharge amount of abraded swarf to the
total abraded amount was defined as dust vacuum efficiency.
[0078] The results are shown in Table 2. TABLE-US-00001 TABLE 1
Sander Dust vacuuming type double action sander SI3111 (made by
Shinano Inc.) Pressure of air 0.6 MPa supplied Rotation speed of
7000 rpm sander Abrasive material UNI HI-CUT P400 phi125 mm disc
(made by Sumitomo 3M Ltd.) Object to be abraded PRIMER SURFACER
JUST URETHANE (made by Kansai Paint Co., Ltd.) Abrasion load 1 kgf
Abrasion time 5 minutes
[0079] TABLE-US-00002 TABLE 2 Shift angle (.degree.) Abrasive
material - Intermediate pad - Dust vacuum Intermediate pad Backup
pad efficiency (%) 0 (matched) 0 (matched) 75 5 0 74 10 (maximum
shift) 0 73 15 0 73 20 0 74 25 0 74 30 0 74 0 (matched) 10 (maximum
shift) 73 5 10 (maximum shift) 72 10 (maximum shift) 10 (maximum
shift) 70 15 10 (maximum shift) 70 20 10 (maximum shift) 71 25 10
(maximum shift) 71 30 10 (maximum shift) 71
[0080] The results of the abrading test show that the dust vacuum
efficiency of the dust vacuuming abrasive tool of the present
invention does not fall so much even when abrasive sheet material
and the backup pad perforations are not exactly aligned. Therefore,
when attaching an intermediate pad or an abrasive material to a
backup pad, it is not necessary to exactly align the respective
perforations and the work of attachment is easy.
Example 2
[0081] In the supporting surface and back surface of an
intermediate pad prepared in the same manner as in Example 1,
channels were formed along lines connecting the perforations in
concentric loops. FIG. 9 is a diagram showing the support surface
and the back surface of the intermediate pad. The channels were
formed by removing the hook element on the supporting surface and
the loop element on the back surface with a width of 3 mm. A dust
vacuuming abrasive tool was obtained in the same manner as in
Example 1, except that this intermediate pad was used, and a
sanding test performed. The results are shown in Table 3.
Example 3
[0082] In the supporting surface and back surface of an
intermediate pad prepared in the same manner as Example 1, channels
were formed along lines completely connecting the perforations.
FIG. 8 is a diagram showing the support surface and the back
surface of the intermediate pad. The channels were formed by
removing the hook element on the supporting surface and the loop
element on the back surface with a width of 3 mm by a melting
(fusion) removing method. A dust vacuuming abrasive tool was
obtained in the same manner as in Example 1, except that this
intermediate pad was used, and a sanding test performed. The
results are shown in Table 3.
Example 4
[0083] A 10 mm-thick sponge sheet was punched into a circle 125 mm
in diameter. A hook material of a mechanical fastener was attached
to the support surface of the resultant sponge disc and a loop
material of the mechanical fastener was attached to the back
surface. In this disc material, seven perforations were formed so
that the perforations overlapped with the perforations provided in
a backup pad made by Shinano Inc. "Sander Pad (with perforations)."
The opening at the center had a diameter of 20 mm and the
perforations in the peripheral portion had a diameter of 11 mm. In
the supporting surface and back surface of this pad material,
channels were formed along lines connecting all the abrasive sheet
material perforations. FIG. 7 is a diagram showing the supporting
surface and the back surface of the intermediate pad. The channels
were formed by removing the hook element on the supporting surface
and the loop element on the back surface with a width of 3 mm by a
melting (fusion) removing method. A dust vacuuming abrasive tool
was obtained in the same manner as in Example 1, except that this
intermediate pad was used, and a sanding test was performed. The
results are shown in Table 3.
Example 5
[0084] An dust vacuuming abrasive tool was prepared in the same
manner as in Example 1, except that a backup pad with seven
perforations made by Shinano Inc. "Sander Pad (with perforations)"
and an intermediate pad the same as that used in Example 4 were
used, and a sanding test was performed. The results are shown in
Table 3.
Comparative Example
[0085] An intermediate pad having seven perforations was prepared
in the same manner as in Example 4, except that no channels were
formed in the supporting surface or the back surface. A dust
vacuuming abrasive tool was prepared in the same manner as in
Example 1, except that a backup pad with seven perforations made by
Shinano Inc. "Sander Pad (with perforations)" and this intermediate
pad were used, and a sanding test was performed.
[0086] The results are shown in Table 3. TABLE-US-00003 TABLE 3
Shift angle (.degree.) Dust vacuum Abrasive material - Intermediate
pad - efficiency Examples Intermediate pad Backup pad (%) 2 10
(maximum shift) 10 (maximum shift) 73 3 10 (maximum shift) 10
(maximum shift) 75 4 10 (maximum shift) 10 (maximum shift) 64 5 10
(maximum shift) 0 (matched) 59 Comparative 0 0 (matched) 38
Example
[0087] The results of the sanding tests show that even if the
number and arrangement of perforations in an intermediate pad and a
backup pad are the same as those of conventional products, the
forming of channels along lines connecting the perforations in an
abrasive sheet material lead to effects the same as those in the
case of forming the perforated structure of the present
invention.
* * * * *