U.S. patent application number 11/314799 was filed with the patent office on 2007-06-21 for sanding tool with molding interface pad.
Invention is credited to Eric R. Cybulski, Jon A. Kirschhoffer, Jonathan M. Lise, Ian R. Owen, John G. Petersen, Ryan Patrick Simmers, Steven E. Turch.
Application Number | 20070141969 11/314799 |
Document ID | / |
Family ID | 38174274 |
Filed Date | 2007-06-21 |
United States Patent
Application |
20070141969 |
Kind Code |
A1 |
Cybulski; Eric R. ; et
al. |
June 21, 2007 |
Sanding tool with molding interface pad
Abstract
A hand-held, manually-operated, sanding tool for use with a
replaceable sheet-like abrasive material, such as sandpaper,
includes a base member, a molded interface pad provided on the base
member to define a working face against which the sheet-like
abrasive material is arranged, and a retaining mechanism arranged
to maintain the sheet-like abrasive material in operative relation
with the interface pad. The base member is formed of a first
material and the molded interface pad is formed of a second
injection moldable material
Inventors: |
Cybulski; Eric R.;
(Woodbury, MN) ; Simmers; Ryan Patrick; (Cottage
Grove, MN) ; Kirschhoffer; Jon A.; (White Bear Lake,
MN) ; Owen; Ian R.; (Baldwin, WI) ; Lise;
Jonathan M.; (Woodbury, MN) ; Turch; Steven E.;
(Blaine, MN) ; Petersen; John G.; (Center City,
MN) |
Correspondence
Address: |
3M INNOVATIVE PROPERTIES COMPANY
PO BOX 33427
ST. PAUL
MN
55133-3427
US
|
Family ID: |
38174274 |
Appl. No.: |
11/314799 |
Filed: |
December 21, 2005 |
Current U.S.
Class: |
451/509 |
Current CPC
Class: |
B24D 15/023
20130101 |
Class at
Publication: |
451/509 |
International
Class: |
B24D 17/00 20060101
B24D017/00 |
Claims
1. A hand-held, manually-operated, sanding tool for use with a
replaceable sheet-like abrasive material, comprising: (a) a base
member; (b) a molded interface pad provided on the base member to
define a working face against which the sheet-like abrasive
material is arranged; and (c) a retaining mechanism arranged to
maintain the sheet-like abrasive material in operative relation
with the interface pad; wherein the base member is formed of a
first material and the molded interface pad is formed of a second,
injection moldable, material.
2. A sanding tool as defined in claim 1, wherein the first material
has a Shore hardness that is greater than the Shore hardness of the
second material.
3. A sanding tool as defined in claim 2, wherein the second
material has a Shore A hardness of less than about 95.
4. A sanding tool as defined in claim 3, wherein the first material
has a Shore D hardness of greater than about 30.
5. A sanding tool as defined in claim 1, wherein the interface pad
is a polymeric material.
6. A sanding tool as defined in claim 5, wherein the interface pad
is an elastomeric material.
7. A sanding tool as defined in claim 6, wherein the interface pad
is formed from at least one of a thermoplastic elastomer, a
thermoplastic vulcanizate, and a thermoplastic rubber.
8. A sanding tool as defined in claim 1, wherein the base member is
formed of an injection moldable synthetic plastic material and the
interface pad is formed of an injection moldable material that is
softer than the material used to form the base member.
9. A sanding tool as defined in claim 1, wherein the interface pad
includes a textured surface.
10. A sanding tool as defined in claim 1, wherein the interface pad
working face includes a macroscopically three-dimensional surface
topography.
11. A sanding tool as defined in claim 6, wherein the surface
topography comprises a regular non-random pattern defined by raised
regions and recessed regions.
12. A sanding tool as defined in claim 1, wherein the base member
contains slots, and the interface pad includes extensions extending
into the slots, thereby to form a secure connection between the
base member and the interface pad.
13. A method of making the sanding tool of claim 1, comprising the
steps of: (a) providing a sanding tool including a base member
having a working face; and (b) forming the interface pad on the
base member by injection molding an elastomeric material over the
working face.
14. A sanding tool as defined in claim 1, wherein the retaining
mechanism is configured to releasably retain the sheet-like
abrasive material.
15. A sanding tool as defined in claim 1, wherein the retaining
mechanism comprises at least one clamping mechanism arranged to
secure the sheet-like abrasive material to the sanding tool.
16. A sanding tool as defined in claim 1, wherein the retaining
mechanism comprises two clamping mechanisms pivotally connected on
opposite ends of the base member to secure the sheet-like abrasive
material to the sanding tool.
17. A sanding tool as defined in claim 1, wherein the interface pad
is molded to the base member.
18. A sanding tool as defined in claim 1, wherein the sanding tool
is user-powered without a motor.
19. A sanding tool as defined in claim 1, characterized by an
absence of adhesive between the base member and the interface
pad.
20. A sanding tool as defined in claim 1, wherein the interface pad
is directly affixed to the base member.
Description
BACKGROUND
[0001] The present invention relates generally to hand-held,
manually-operated, sanding tools that use a sheet of abrasive
material such as sandpaper.
[0002] Manually-operated hand sanding tools, such as sanding
blocks, are commonly used with abrasive sheets, such as
conventional sandpaper, to hand sand or finish a work surface. A
commercially available sanding block is the 3M.TM. Rubber Sanding
Block available from 3M Company, St. Paul, Minn. Hand sanding tools
may include a foam interface pad that is adhesively bonded to the
working face of the sanding tool. Such interface pads, however,
suffer from one or more drawbacks or shortcomings. It would be
desirable to provide a hand-held, manually-operated, sanding tool
that includes an interface pad that overcomes the drawbacks and
shortcomings of sanding tools having adhesively bonded foam
interface pads.
SUMMARY
[0003] The present invention provides a hand-held,
manually-operated, sanding tool for use with a replaceable
sheet-like abrasive material that includes a base member formed of
a first material, a molded interface pad formed of a second
injection moldable material provided on the base member, thereby
defining a working face against which the sheet-like abrasive
material is arranged, and a retaining mechanism arranged to
maintain the sheet-like abrasive material in operative relation
with the interface pad.
[0004] In one aspect, the first material has a Shore hardness that
is greater than the Shore hardness of the second material (i.e. the
interface pad is softer than the base member). In a more specific
aspect, the first material has a Shore D hardness of greater than
about 30, and the second material has a Shore A hardness of less
than about 95.
[0005] In one embodiment, the interface pad is a polymeric
material. In a more specific embodiment, the interface pad is an
elastomeric material. In another aspect, the interface pad includes
a textured working surface opposite the base member. In more
specific aspects, the interface pad working face includes a
macroscopically three-dimensional surface topography. The surface
topography may comprise a random three-dimensional surface
topography or it may comprise a regular non-random pattern defined
by raised regions and recessed regions.
[0006] In another aspect, the base member contains slots and the
interface pad includes extensions extending into the slots, thereby
to form a secure connection between the base member and the
interface pad.
[0007] In yet another aspect, the present invention provides a
method of making a hand-held, manually-operated, sanding tool for
use with a replaceable sheet-like abrasive material comprising a
base member formed of a first material, a molded interface pad
formed of a second injection moldable material provided on the base
member, thereby defining a working face against which the
sheet-like abrasive material is arranged, and a retaining mechanism
arranged to maintain the sheet-like abrasive material in operative
relation with the interface pad, wherein the method comprises the
steps of providing a sanding tool including a base member having a
working face, and forming an interface pad on the base member by
injection molding an elastomeric material over the working
face.
[0008] Advantages of certain embodiments of the invention include
improved sanding capability, improved product design flexibility
(that is, the product design can be more easily tailored or adapted
to a specific end-use application), easier and less expensive
manufacturing, and a sanding tool that is easier and more
comfortable to use.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention will be further described with
reference to the accompanying drawings, in which:
[0010] FIG. 1 is a perspective view of a hand-held,
manually-operated, sanding tool having a molded interface pad
according to the invention;
[0011] FIG. 2 is a side view of the sanding tool of FIG. 1;
[0012] FIG. 3 is a detailed view of the base member and the
interface pad; and
[0013] FIGS. 4a and 4b are plan views showing alternate
three-dimensional surface topographies for the interface pad.
DETAILED DESCRIPTION
[0014] Referring now to the drawings, wherein like reference
numerals refer to like or corresponding parts throughout the
several views, FIGS. 1 and 2, show a hand-held, manually-operated
sanding tool or sanding block 2 for use with a flexible,
replaceable, sheet-like abrasive material 40. The term
"manually-operated" refers to the fact that the tool 2 is not a
power tool. That is, all of the power for the tool is provided by
the user and the tool itself does not include a motor. The term
"sheet-like abrasive material" refers to thin, flexible, typically
square or rectangular sheets of abrasive material having discrete
ends that can be attached to a sanding block. Such sheet-like
abrasive materials include, for example, conventional sandpaper,
flexible sanding scrims, non-woven abrasive materials such as
Scotch-brite.TM. available from 3M Company, St. Paul, Minn., and
thin flexible abrasive sheet materials such as those described in
U.S. Pat. No. 6,613,113 (Minick et al.), the entire contents of
which are hereby incorporated by reference. The tool may also find
use with non-abrasive sheet-like materials such as dust removing
tack cloth materials. The term, however, does not include endless
belts of abrasive material commonly used on power sanding tools, or
die cut sheets that are sold pre-cut to match the size and shape of
a particular sanding tool as is commonly done for power detail
sanding tools.
[0015] The sanding tool 2 shown and described herein is described
more fully in U.S. patent application Ser. No. 11/117,932 filed
Apr. 29, 2005, the entire contents of which are hereby incorporated
by reference. For the present invention, however, the sanding tool
2 generally is not particularly significant as long as it is
capable of including an interface pad and includes certain basic
features such as the ability to receive and retain a sheet-like
abrasive material. Thus, it will be understood that the sanding
tool 2 shown and described below is intended to represent any
sanding tool capable of having a molded interface pad.
[0016] The sanding tool 2 includes a base member 4 and a pair of
clamping mechanisms 6, 8 connected with opposed ends of the base
member 4. Although the sanding tool 2 is shown with clamping
mechanisms 6, 8 at both ends, it will be recognized that one or
both of the clamping mechanisms 6, 8 may be replaced with a
conventional mechanism for securing the abrasive sheet-like
material 40 to the tool. It will also be recognized that although
the base member 4 is shown as being rectangular, it may also be
square or other shapes that lend themselves for use with
conventional abrasive sheets.
[0017] The base member 4 has first 10 and second 12 opposed ends
and a generally planar bottom surface 14. Each end 10, 12 of the
base member 4 has an inclined or angled contact surface 16, 18,
respectively, opposite the bottom surface 14. In this manner, the
contact surfaces 16, 18 and bottom surface 14 form an acute angle
relative to the associated adjacent end 10, 12, respectively.
[0018] Each clamping mechanism 6, 8 is pivotally connected with
opposite ends 10, 12 of the base member 4 adjacent the contact
surface 16, 18, respectively, thereby defining a jaw into which the
ends 40a, 40b of a sheet-like abrasive material 40 may be inserted.
Each clamping mechanism 6, 8 is movable between a closed position
shown in FIG. 1, and an open position shown in FIG. 2. In the
closed position, the clamping mechanisms 6, 8 are fully actuated
toward the associated contact surfaces 16, 18, respectively, and,
when no abrasive material is present, are arranged adjacent to the
contact surfaces 16, 18, respectively. In the open position, the
clamping mechanisms 6, 8 are spaced from the associated contact
surfaces 16, 18, thereby defining gaps 20, 21, respectively,
between the base member 4 contact surfaces 16, 18 and the clamping
mechanisms 6, 8.
[0019] Each clamping mechanism 6, 8 includes a flexible tensioning
member 22, 24 arranged to face the associated contact surface 16,
18. Arranged in this manner, as the clamping mechanisms 6, 8 are
lowered toward the base member 4 to secure the abrasive material 40
to the tool 2, the terminal edges of the tensioning members 22, 24
slidably engage the contact surfaces 16, 18. Thus, when an end 40a,
40b of the abrasive sheet 40 is inserted in the gap 20, 21 between
the base member 4 and a clamping mechanism 6, 8, and the clamping
mechanism is moved from its open position to the closed position,
the edge of the tensioning members 22, 24 will frictionally engage
the end 40a, 40b of the sheet of abrasive material 40.
[0020] As the clamping mechanisms 6, 8 are further urged toward the
contact surfaces 16, 18, the tensioning members 22, 24 grip the
respective ends of the abrasive sheet 40a, 40b and move it upwardly
along the inclined contact surfaces 16, 18 away from the associated
end 10, 12, thereby drawing the sheet of abrasive material further
into the gap 20, 21. In addition, as the clamping mechanisms 6, 8
are urged against the contact surfaces 16, 18, the tensioning
members 22, 24 bow or flex such that the bowed surface of the
tensioning members 22, 24 will engage the contact surfaces 16, 18,
thereby increasing the overall contact surface area between the
tensioning members 22, 24 and the sheet of abrasive material 40. In
this manner, slack in the abrasive sheet 40 is taken up, thereby
tightening the fit of the abrasive sheet 40 against the bottom 14
of the base member 4.
[0021] In the illustrated embodiment, the tensioning members 22, 24
are thin flexible strips of metal, such as a leaf spring, that
generally return to their original positions when the applied force
is released. Other materials such as a stiff resilient rubber or
synthetic plastic material may also be used. To distribute the
force applied by the tensioning members 22, 24 to the ends abrasive
sheet 40a, 40b evenly (both during the installation of the abrasive
sheet 40 onto the tool and while the abrasive sheet is being held
onto the tool), the tensioning members 22, 24 extend continuously
across the entire width of the clamping mechanisms 6, 8. By
distributing the force in this manner, the tensioning members 22,
24 have a reduced tendency to tear or otherwise damage the abrasive
sheet material 40.
[0022] To further reduce the likelihood that the ends of the
tensioning members 22, 24 will dig into the abrasive sheet 40, and
thereby possibly damage the abrasive sheet, in an alternative
embodiment, the tensioning members 22, 24 may be curved or bowed
inwardly such that the tensioning members 22, 24 have curved
surfaces that face the contact surfaces 16, 18, and engage the
contact surfaces when the clamping mechanisms 22, 24 are
closed.
[0023] In accordance with a characterizing aspect of the sanding
tool 2, a molded interface pad 26 is provided on the bottom surface
of the base member 4. The interface pad 26 defines the surface
against which the sheet-like abrasive material 40 is secured. By
providing a molded interface pad 26, the base member 4 and
interface pad 26 form an integrally molded body including an upper
portion defined by the base member 4, and a lower portion defined
by the interface pad 26. The base member 4 is typically formed of a
first polymeric material, and the interface pad 26 is typically
formed of a second polymeric material. The second polymeric
material used to form the interface pad 26 is typically softer than
the material used to form the base member 4. The molded interface
pad 26 may be formed of any moldable material but is typically a
soft, resiliently-flexible, elastomeric, injection moldable
material. Suitable injection moldable materials include natural and
synthetic rubbers including latex and butyl rubber, thermoplastic
elastomers such as polyurethane elastomers, thermoplastic
vulcanizate, and thermoplastic rubber. Suitable materials for the
interface pad 26 typically have a Shore A hardness of less than
about 95 and, more typically, less than about 70. A suitable
material for the molded interface pad 26 is available from Advanced
Elastomer Systems, an affiliate of ExxonMobil Chemical, under the
trade designation Santoprene.
[0024] Generally, the base member 4 is formed of a material having
a Shore hardness that is greater than the Shore hardness of the
material used to form the interface pad. Suitable materials for the
base member include hard synthetic plastic materials, typically
thermo set or thermoplastic materials such as ABS (acrylonitrile
butadiene styrene), polypropylene, polyethylene, and blends
containing such materials. Suitable materials for the base member 4
typically have a Shore D hardness of greater than about 30. A
suitable material for the base member 4 is available from GE
Plastics under the trade designation Cycolac and Cycoloy (an ABS
polycarbonate blend).
[0025] FIG. 3 is a detailed view showing the interconnection
between the base member 4 and interface pad 26. In the illustrated
embodiment, the base member 4 contains recesses or slots 28 and the
interface pad 26 includes extensions 30 that extend into the slots
28. In this manner, a mechanical connection, which resists
dissociation, is formed between the base member 4 and the interface
pad 26. To further enhance the interconnection between the
interface pad 26 and the base member 4, and thereby prevent the
interface pad 26 from separating from the base member 4, the slots
28 include optional flared end regions 28a, and the extensions 30
include flared terminal portions 30a that extend into the flared
end regions 28a of the slots 28. Other structural features for
forming the mechanical attachment between the base member 4 and the
interface pad 26 are contemplated in connection with the present
invention. The mechanical connection may be formed, for example, by
a single protrusion, which may have a variety of shapes, that mates
with a cooperating recess. The protrusion and recess may be formed
in either the base member 4 or the interface pad 26.
[0026] Alternatively, base member 4 and the interface pad 26 may be
formed via a chemical bond. When attached by a chemical bond, the
interface between the base member 4 and the interface pad 26 may be
generally planar (i.e. the base member 4 and the interface pad 26
each include generally planar surfaces that are attached to each
other) or the interface may include structural features such as
those described above to further enhance the interconnection
between the base member and the interface pad 26. The chemical bond
is formed by selecting compatible materials that form a strong
chemical bond.
[0027] As shown in FIG. 4, the exposed working face of the
interface pad 26 (i.e. the surface of the interface pad 26 opposite
the base member 4 against which the abrasive sheet 40 is arranged)
may include a textured surface 32 having a three-dimensional
surface topography. The three-dimensional surface topography is
typically macroscopic meaning the height differential between the
raised regions and the recessed regions is greater than about 1
millimeter. As shown in FIG. 4a, the textured surface 32 may be a
random pattern of raised regions 34 separated by recessed regions
36 or, as shown in FIG. 4b, the textured surface may be a regular
repeating pattern of raised regions 34 and recessed regions 36.
Other surface geometries are contemplated in connection the present
invention. For example, the size and shape of the raised and
recessed regions may be varied or tailored depending on the type of
abrasive sheet used and/or depending on the specific end use
application for the tool.
[0028] The combination of the base member 4 and the interface pad
26 may be formed, for example, using known multi-material injection
molding techniques including co-injection molding, overmolding, and
multi-shot molding. For example, the base member 4 may be formed by
injection molding a suitable material, such as ABS, into a mold to
form the base member 4, and the interface pad 26 may be formed by
injection molding a suitable material, such as Santoprene, to form
the interface pad 26. Alternatively, the base member 4 may be
formed by casting or other known techniques.
[0029] Injection molding the interface pad 26 offers a number of
advantages over the use of conventional interface pads, which are
foam pads that are adhesively bonded to the sanding tool 2. First,
because the molded interface pad is injection molded, the
additional steps of die cutting a foam sheet to the appropriate
size and adhesively bonding the foam pad to the bottom of the base
member 4 are eliminated. This simplifies the assembly process and
also eliminates the raw material costs associated with the foam pad
and adhesive. Injection molding the interface pad 26 also reduces
the likelihood of failures between the interface pad and the base
member 4 (i.e. injection molding provides a chemical and/or
mechanical bond between the interface pad 26 and base member 4 that
is unlikely to allow the interface pad 26 to inadvertently separate
from the base member 4). The injection molded interface pad 26 may
also include a variety of textures and/or patterns, it may be
formed of any number of suitable moldable polymer materials
depending on the desired durability and conformability properties,
and it may be formed in a variety of colors or thicknesses, thereby
greatly increasing the design options and design flexibility of the
tool, and further allowing the tool design to be easily tailored
for specific end uses.
[0030] The sanding tool 2 also includes a handle 46. In the
illustrated embodiment, the handle 46 includes a neck portion 46a
that extends upwardly from a central region of the base member 4,
and includes an enlarged head portion 46b located at the end of the
neck 46a that defines a knob 48 that can be readily grasped by a
user to maneuver and control the movement of the tool 2. To provide
the user with a more comfortable grip, the knob 48 portion of the
handle 46 preferably comprises an interior region 48a formed of a
relatively hard first material and a peripheral region 48b formed
of a relatively soft rubber-like second material that is easier to
grip and thereby provides the user with improved handling. The
first relatively hard material, may be, for example, a hard
synthetic plastic, and the relatively soft second material may be,
for example, a thermoplastic elastomer, rubber, rubber-like
materials or foam.
[0031] The tool 2, including the base member 4, clamping mechanisms
6, 8 and handle 46, may be formed of any suitable material
including, for example, wood, metal, synthetic plastic, or a stiff
rubber.
[0032] Those of ordinary skill in the art may appreciate that
various changes and modifications may be made to the invention
described above without deviating from the inventive concept. For
example, it will be recognized that the size of the tool may be
adapted so it can be used with the various standard sizes of
commercially available abrasive sheets. Thus, the scope of the
present invention should not be limited to the structures described
in this application, but only by the structures described by the
language of the claims and the equivalents of those structures.
* * * * *