Note: Descriptions are shown in the official language in which they were submitted.
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ABRASIVE PLATE
BACKGROUND
Te~hni~l Field
The present disclosure relates generally to a unique surfacing tool.
More particularly, the present disclosure relates to an abrasive metal plate adapted for
use in a s~n-ling machine, and to a method for producing an abrasive metal plate.
B~k~round of I~lP~ell Art
While sandpaper and similar materials are generally inexpensive, they
become unserviceable through use in short periods of time. S~n-~parer, for example,
is easily ruptured as the abrasive particles attached to the base of the s~n~ )el
become loosened, worn and clogged. The use of s~n~lrarer with motor-powered tools
exacerbates this problem in that due to the high speed of operation, most of theabrasive particles become quickly clogged with large amounts of wood flour or the
particles become ~et~ from the abrasive surface of the s~n-lr~rer.
To overcome this problem, abrasive metal sheets have been developed
with integrally formed protrusions configured to perform abrading applications. For
example, in U.S. Patent No. 2,820,281, a metallic abrasive sheet is adapted to be
used in the manner of s~ntlr~rer. The abrasive sheet is flexible so that it may be
conformed to supporting blocks. Projections on an abrasive surface are formed bypuncturing apertures in the sheet. In U.S. Patent No. 3,545,308, a perforated
abrasive metal sheet is provided for use with a reciprocating sander. The abrasive
metal sheet is formed with generally rectangular shaped apertures which are punched
in a metal sheet to form an abrasive surface. In U.S. Patent No. 3,583,107, a
flexible metal sheet is suggested for use with power sanders. Cutting edges for the
sheet are formed by driving punches of various geometric shapes through the metal
sheet.
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While abrasive metal sheets have a service life greater than that of
sandpaper, these sheets have been found to be more difficult than sandpaper to use
with motor-powered sanders, e.g., random orbit sanders, vibratory sanders, etc.
Rec~nce of the large number of protrusions in the metal sheet, the force tr~n.cmitt~d
5 from a surface being treated by the power sander through the plate is generally
unb~l~n~ed. As such, the power sander has a tendency to pull in one direction as the
sander is moved over the surface being treated, making it difficult for an operator to
control the power sander and tiresome to operate the sander for s-lct~inrd periods of
time.
Accordingly, a need exists for an abrasive metal sheet adapted for use
with motor-powered sanders that overcomes the above-noted disadvantages and is easy
to make and use.
SUMMARY
In accordance with the present disclosure, an abrasive surfacing plate,
preferably in the form of a perforated metal sheet, is provided. The abrasive plate
includes a planar base member having a plurality of transversely aligned rows ofprotrusions exten-ling from an abrasive face of the base member. Each of the
protrusions has a bottom edge portion ~tt~rllPd to the base member and a distal edge.
The protrusions in each transverse row are oriented substantially i-lentic.~lly to the
other protrusions in the same transverse row. The protrusions in each row are
oriented such that the bottom edge portion of the protrusions are at an angle from
about 45~ to 135~ with respect to the bottom edge portions of the protrusions in each
adjacent row.
Each protrusion may have a triangular shaped body in which one side
of the body forms the bottom edge portion of the protrusion and the corner of the
body opposite to the bottom edge portion forms the distal edge of the protrusion. The
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base member may have at least one side wall configured to be releasably fastened to
engagement structure formed on a power sander. The abrasive plate is preferably
monolithir~lly formed from thin stock carbon steel.
The present invention also relates to a method of producing an abrasive
5 plate including the steps of: providing a base member; forming a plurality of rows of
protrusions in the base member wherein the protrusions in each respective row have a
common orientation and wherein protrusions in each row are oriented such that a
bottom edge portion of the protrusions are at an angle from about 45~ to 135~ with
respect to the bottom edge portions of the protrusions in each adjacent row. The10 method may further include the step of forming at least one side wall substantially
perpen-lic~ r to the base member adapted to be releasably fastened to engagementstructure on a power sander. Preferably, the step of forming the at least one side
wall includes rolling an edge portion of the base member to form the side wall.
In an al~ ative method of producing an abrasive plate, a plurality of
15 holes are formed in a sheet of material having a subst~nti~lly smooth surface. At
least one slot and preferably a pair of slots which extend outwardly from at least some
of the holes is also formed in the sheet of material to define tabs. The slots may
include a pair of parallel slots to define a tab having a generally rectangular body
portion with an arcuate distal end having first and second edge portions. Alternately,
20 the slots may include first and second converging slots which define a tab having a
generally triangular body portion with an arcuate distal end having first and second
edge portions. Any desired percentage of the tabs may be selectively raised or
deformed to protrude above the subst~nti~lly smooth surface thereby forming an
abrasive surface. The number of tabs raised may be chosen to control the coarseness
25 of the abrasive surface of the abrasive plate; e.g., raising a low number of tabs
produces a coarse abrasive surface, while raising a higher number of tabs produces a
finer abrasive surface.
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The abrasive plate described herein provides increased service life over
sandpaper and similar materials and may be adapted to be used with conventional
power sanders without being affected by the drawbacks associated with known
abrasive plates. In addition, the abrasive plate can advantageously be m~nllf~ red in
5 volume in an efficient manner.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embo-lim~nt.~ of the invention are described hereinbelow with
reference to the drawings wht;~
FIG. lA is a sch~m~tic perspective view of an abrasive plate made in
accordance with the present invention;
FIG. lB is a sch~-m~tic top view of an alternate embodiment of the
abrasive plate of the present invention;
FIG. lC is a schpm~sic front elevational view of the abrasive plate
15 shown in FIG. lB;
FIG. 2 is a schematic bottom view of the abrasive plate of FIG. lA;
FIG. 3 is a sch~ tir side cross-sectional view of the abrasive plate
taken along section line 3 of FIG.2;
FIG. 4 is a sch~m~ti~ perspective view showing details of the
protrusions of the abrasive plate of FIGS. lA-lC;
FIG. 5 is a perspective view of another embodiment of the abrasive
plate;
FIG. 6 is a top view of the abrasive plate shown in FIG. 5;
FIG. 7 is a perspective cutaway view of a portion of the abrasive plate
shown in FIG. 5;
FIG. 8is a top cutaway view of a portion of the abrasive plate shown
in FIG. 5;
FIG. 9 is a cross-sectional view taken along section line 9-9 of FIG. 8;
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FIG. 10 is a top pel~pecLive view of another embodiment of the
abrasive plate;
FIG. 11 is a top view of the abrasive plate shown in FIG. 10;
FIG. 12 is a perspective cutaway of a portion of the abrasive plate
S shown in FIG. 10;
-
FIG. 13 is a top cutaway view of a portion of the abrasive p}ate shownin FIG. 10; and
FIG. 14 is a cross-sectional view taken along section line 14-14 of FIG.
13.
DESCRIPI ION OF THE PRE~ERRED EMBODIl\~ENTS
Preferred embodiments of the ~leselllly disclosed abrasive plate will
now be described in detail with reference to the drawings, in which like l~fel~nce
numerals designate identical or corresponding elements in each of the several views.
Referring to FIGS. lA-lC, an abrasive plate shown generally as 10
includes a base member 12 having multiple rows 13,-13N of protrusions 14 (where N
refers to the highest number row of a plurality of consecuLively numbered rows).Protrusions 14 extend ouLw~ldly from the abrasive plate 10 to collectively form an
abrasive surface on base member 12. Preferably, the abrasive plate 10 is constructed
20 from thin stock carbon steel and has a rectangular shape, although other materials
having the requisite strength requilullen~ may be used to construct the plate and the
plate 10 may take any desired shape.
Abrasive plate 10 is formed with side walls 16, 18, 20 and 22. The
sidewalls are configured to be releasably f~tenPcl to engagement structure of a power
25 sander or other device commonly used for holding s~n~paper and the like (not
shown). Side walls 16 and 20, for example, may include resilient fingers 21 which
engage recesses or other structure disposed on a power sander to secure the plate 10
- to the sander. The resilient fingers 21 may be formed by double folding a portion of
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sidewalls 16 and 20 (FIG. lA) or by providing tabs in sidewalls 16 and 20 (FIGS. lB
and lC). The resilient fingers 21 facilitate quick and easy removal and attachment of
abrasive plate 10 from a power sander.
The abrasive plate 10 may be monolithically formed from a sheet of
material, e.g., thin stock carbon steel. Preferably, sidewalls 16, 18, 20 and 22 are
formed by folding the edges of the base member 12 to a position substantially
perpen-lieul~r to the base member. In particularly useful embodiments, the abrasive
plate 10 may be about .020 inches thick. The plate can be dimensioned to be
adaptable to 1/4, 1/3 or 1/2 sheet power sanders cullelllly available in the market.
The abrasive plate 10 may also include one or more ~Lir~elling ribs 23 formed on the
surface of the base member 12 to lcinfol~;e the plate and prevent flexing of base
member 12. Although only one rib 23 is shown, a plurality of ribs at various
orientations or positions may be provided.
Referring now to Fig. 2, a plurality of rows 13l-13N of protrusions 14
are formed in the base plate 10. The protrusions 14 are formed such that each
protrusion 14 in a row 13; (where i refers to an exemplary row of the plurality of
rows) of protrusions 14 has subst~nti~lly the same orientation as other protrusions 14
in that row. The protrusions 14 in adjacent rows are oriented such that a bottom edge
portion of the protrusions are at a predetermined angle from about 45~ to about 135~
with respect to the bottom edge portions of the protrusions in row 13j. By varying
the orientation of the protrusions 14 in adjacent rows in the manner described above,
the forces tr~n.~mittecl through the abrasive plate 10 during operation of a powe}
sander may be subst~nti~lly b~l~nred to elimin~te or subst~nti~lly reduce pulling of
the power sander in any one direction during a s~n~ing operation.
In an illustrative embodiment of the present invention shown in FIG. 3,
each of the protrusions 14 is triangularly-shaped and includes a planar face 24, a
bottom edge portion 26 attached to the base member 12, a side wall 28, and a distal
edge 30. The protrusion 14 is formed such that the planar face 24 and the base
member 12 define an angle e of about 60~ to about 120~ (see also FIG. 4). The
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protrusions 14 may be formed having a height of from about .005 to about .1 inches.
The specific dimensions of the abrasive plate 10 and of the protrusions 14 will vary
according to the intended use of the plate 10.
Referring now to FIG. 4, in a preferred embodiment of the disclosure,
S the bottom edge portions 26 of protrusions 14 in each row are oriented at an angle of
approximately 90~ with respect to the bottom edge portions 26 of the protrusions 14
in adjacent rows. The bottom edge portions 26 of the protrusions 14 in alternate rows
(i.e., row 13j and row 13j+~ may be rotated 180~ and still provide a bal~nre~l power
~s~n-ling device.
Preferably, the protrusions 14 are formed in a single sheet of material
using a meç~l~nir~l punch having a desired shape to form the rows 13j-13N of
protrusions 14. As stated above, each protrusion 14 in a row of protrusions is formed
having a subst~nti~lly identical orientation to the other protrusions 14 in that row.
The bottom edge portions 26 of the protrusions 14 in each row are oriented at anangle of about 45~ to about 135~ with respect to the bottom edge portions 26 of the
protrusions in adjacent rows. The edges of the abrasive plate are meçh~nir~lly shaped
via rolling and cutting into a configuration adapted to be fa~ten~l to engagement
structure formed on a power sanding device.
In use, the abrasive plate 10 is fastened to a power sanding device by
fastening the sidewalls 16, 18~ 20 and 22 to engagement structure on the power
~nAing device such that the abrasive surface of the abrasive plate 10 faces away from
the s~n-1ing device. The abrasive surface is pressed against the surface to be treated
and the power .s~n~ling device is ~ct -~t~cl to cause the abrasive surface to move
relative to the surface being treated. If the angle e defined by the planar surface 24
of the protrusions 14 and base member 12 is 90~, the entire distal edge 30 of the
protrusion will engage the surface being treated. For all other angles, the leading
point 32 or the trailing point 34 of the protrusions 14 will first engage the surface
being treated.
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A further embodiment of the presently disclosed abrasive plate shown
generally as 100 will now be described with reference to FIGS. 5-9. Referring toFIGS. 5 and 6, abrasive plate 100 includes a base member 112 having multiple rows
113,-113N of protrusions 114 extending ou~w~ldly thclc~lu~ll to collectively form an
abrasive surface 116. Preferably, abrasive plate 100 is monolithically constructed
from thin stock carbon steel and has a generally rectangular shape, although other
materials having the requisite strength requirements and having dirr~lcll~ shapes (e.g.,
circular, triangular, etc.) may also be used to construct abrasive plate 100. Although
not illustrated, abrasive plate 100 may include factening structure, such as sidewalls
16 (FIG. lA), configured to releasably engage engagement structure of a power
sander or other device commonly used to support s~n~paper and the like. Preferably,
abrasive plate 100 includes hook and loop fasteners (not shown), such as Velcro~, to
secure the plate 100 to supporting structure. The corners 117 of base member 112are preferably rounded to remove all sharp edges from the plate 100.
Referring also to FIGS. 7-9, protrusions 114 extend outwardly from
surface 116 and define an angle e of (FIG. 9) from about 30~ to about 150~ with
respect thereto. Preferably, angle e is in the range of about 60~ to about 85~. Each
protrusion 114 has a body portion 118 att~rh~ to base member 112 having a pair of
linear sidewalls 119 and an arcuate distal wall 120 having a pair of edge portions 121.
Each protrusion 114 is preferably commonly oriented with respect to other protrusions
in the same row, while protrusions 114 in adjacent rows have orientations which are
offset with respect to each other, and are preferably offset by about 180~.
Preferably, plate 100 is m~mlfn~tllred by forming a plurality of holes
122 in a sheet of material having a subs~nti~lly smooth surface. At least one slot and
preferably a pair of slots 124 which extend outwardly from each of the holes 122 is
also formed in the sheet of material to define tab members. After the holes 122 and
slots 124 are formed in base member 112, some or all of the tab-members may be
deformed or raised to protrude from the smooth surface to define protrusions 114.
The number of tab members raised may be chosen to control the coarseness of
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abrasive surface 116. Those skilled in the art will appreciate and it is furthercontemplated that in an alternate embodiment (not shown), multiple pairs of slots 124
can be formed in the base member which slots extend ~ulwaldly from each hole 122to define multiple tab members about each hole 122. Subsequently, some or all of the
5 multiple tab members formed at each hole may be selectively deformed to form
protrusions 114 and provide abrasive surface 116 having a desired coarseness.
It is noted that any known appa~lus may be used to form the holes 122
and slots 124 in base member 112 and to deform the tab members. For example,
holes 122 may be drilled into base member 112 and slots 124 may be punched
through base member 112, or both holes 122 and slots 124 may be formed using a
laser. It should be understood that the slots need not extend entirely through the bore
member, but can merely be score lines that provide a line of weakness along which
the tab members are subsequently punched out. Moreover, a punch may be used to
raise the tab members to form protrusions 114. By providing holes 122 in base
member 112, the tip of the punch used to raise the tab members can be inserted into
one of the holes 122 such that a side portion of the punch deforms the tab member.
This elimin~tes high loads on the tip of the punch and greatly increases its useful life.
As illustrated in FIGS. 5-9, body portion 118 of protrusion 114 may
have a substantially rectangular shape. However, protrusions having other shapes are
also envisioned. Referring to FIGS. 10-14, an alternate embodiment of the abrasive
plate is shown generally as 200. Briefly, abrasive plate 200 includes a base member
212 having multiple rows 213l-213N of protrusions 214 extending ou~w~rdly thel~fiu
to collectively define abrasive surface 216. Protrusions 214 extend oulwaldly from
abrasive surface 216 to define an angle e (FIG. 14) of from about 30~ to about 150~
with respect thereto. Each protrusion 214 includes a body portion 218 attached to
base member 212, a pair of linear sidewalls 219 and an arcuate distal wall 220 having
a pair of edge portions 221. Body portion 218 has a generally triangular shape,
- although other shapes may also be used. Preferably, each protrusion 214 is
commonly oriented with the other protrusions in the same row, whereas protrusions
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214 in adjacent rows have orientations which are offset from each other and are
preferably offset by about 180~. It is noted that abrasive plate 200 may be
m~mlf~ red using a process similar to that described to manufacture abrasive plate
100. However, the pair of slots 124 which extend outwardly from each of holes 122
5 are formed parallel to each other, whereas the pair of slots 224 which extend
~uLw~ldly from each of holes 222 converge toward the respective hole 222.
As in the previous embodiment, it is further contemplated that more
than one pair of slots can be formed at each hole. In this Illal~ , a plurality of tabs
can be produced around some or all of the holes. By raising or inclining all of the
10 tab~ formed, a fine abrasive surface is produced. By raising less than all the tabs, a
coarser abrasive plate is provided.
It will be understood tnat various modifications may be made to the
embo~limentc disclosed herein. For example, the abrasive plate may be adapted to be
fitted onto a manual .c~n-ling block, or constructed in belt form having a thirknl~c.c of
from about .005 to .060 inch such that it may be fitted on a belt sander. As another
example, the pair of slots which define the tab members need not be linear but may
be curved or angled to define tab members having a variety of shapes. As yet
another example, rather than forming round holes as illustrated at 122 and 222, in
FIGS. 5-14, holes of other configurations (e.g., squares, rectangular, triangular, oval,
20 etc.) can be used. Therefore, the above description should not be construed as
limiting, but merely as exemplifications of l~Lcr~ ,d embodiments. Those skilled in
the art will envision other modifications within the scope and spirit of the claims
appended hereto.
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