Note: Descriptions are shown in the official language in which they were submitted.
CA 02437879 2003-08-08
GRINDING TOOL FOR PROFILED STRIPS OF WOOD OR THE LIKE
The invention relates to a sanding tool for moldings of wood or the like,
having a frame drivable in rotation on which a pad made of an elastic material
is
S mounted in torsionally rigid fashion, and which sanding tool is coated with
an
abrasive.
It is generally known that moldings are known in many distinct profiles. They
are used for many purposes including interior finishing. A high surface
quality, which
can only be achieved by sanding, is required. The sanding tool in question can
be a
ring sanding wheel, which is faced with the abrasive all the way around. It
can also,
however, be a so-called segmental sanding wheel in which only raised or
protruding
surfaces are coated with the abrasive. The pad is made of an elastic or
plastic material,
preferably sponge rubber. In the case of the sanding tools known heretofore,
this pad
mounted on the frame is adapted to the various profiles of the moldings to be
sanded.
1 S As a consequence, the pad as well as the abrasive backing must be replaced
when the
profile is changed. Costs for sanding tools are correspondingly high because
relatively
many molding profile shapes are sanded with one sanding machine.
The goal of the invention is to fashion a sanding tool of the kind described
more closely at the outset in such a way that tool costs are markedly reduced
without
the need to accept a diminution in the quality of the moldings to be sanded.
This goal is achieved in that the pad has a constant profile for the various
molding profiles to be sanded.
While the pad holder was previously adapted to the profiles of the moldings to
be sanded, now a universal pad is now created and designed such that all
profile
2S shapes can be machined therewith. The pad holder is customarily ring-
shaped.
Although the abrasive substrates vary in profile shape, the inside diameter
always
remains the same, so that they can be slipped onto the pad holder. The sanding
tool
according to the invention makes it possible that the clamping system need be
procured only once, while the abrasive substrates must be adapted to the
profiles of
the moldings. The tool according to the invention can accordingly also be
regarded as
a universal tool.
In a preferred embodiment, the pad has a cylindrical ring on which an
CA 02437879 2003-08-08
2
outwardly oriented radial support ring is molded in at least one frontal end
region.
This design is especially suitable for an embodiment in which the sanding tool
is
fashioned in a ring shape and the circumferential surface is completely coated
with an
abrasive. In the case of a sanding tool containing a plurality of segments,
the frame
holding the sanding segment could be fashioned accordingly. In an advantageous
development, the support ring has a groove, preferably running all the way
around, on
the side facing toward the cylindrical ring. The abrasive backing then engages
with
the associated frontal end region in this groove. Centering or guidance is
accomplished in this way. If the sanding tool is made up of a plurality of
segments,
the associated ends of the abrasive backings engage in this groove. The
abrasive is
advantageously attached to an abrasive backing adapted to the outline of the
molding
to be sanded. This abrasive backing is then slipped onto the pad holder. The
clamping
system must ensure that it does not execute any relative movement in the
operating
state. If the sanding tool is made up of segments, the abrasive is attached to
the
sanding segments adapted to the outline of the moldings to be sanded.
It is also possible, however, for a pad holder in ring form to be used again,
but
for the circumferential surface of the abrasive backing to be segmental, that
is,; there
are high portions and low portions, and for only the elevated surfaces to be
coated
with the abrasive. If the sanding tool is made as a segmental sanding tool,
the pad
holder could also be made of a plurality of parts. The abrasive backing, as in
the
known embodiments, is made up of an elastic or plastic material, preferably
sponge
rubber. The pad or the pad holder, however, is fashioned so as to be stable in
shape,
and in a preferred embodiment is fabricated from metal, for example steel or
aluminum. It advantageously has a central hub and a seat ring running
concentrically
thereto and bearing the pad. This hub and the seat ring are connected to one
another
by a flange-like face ring at at least one frontal face. In a preferred
embodiment, the
sanding tool is driven in rotation about a vertical axis. The cylindrical ring
of the pad
holder then has, in a preferred embodiment, a vertical circumferential
surface. The
support ring adjacent thereto has, accordingly, a horizontal surface.
Furthermore, the
height of the cylindrical ring is substantially greater than the diameter
difference of
the support ring.
The invention will now be explained in greater detail on the basis of the
CA 02437879 2003-08-08
3
drawings, in which:
Figure 1 shows an embodiment of the sanding tool according to the invention
in sectional view.
Figure 1 depicts a sanding tool 10, designed as a sanding wheel and whose
circumferential surface is fully coated with an abrasive 11, for example with
sandpaper. In the exemplary embodiment depicted, sanding tool 10 is designed
so that
a curve in the shape of a quarter-circle can be sanded on a molding, not
depicted. This
profile shape should be regarded as an example because in principle all
profile shapes
can be sanded. In the exemplary embodiment
depicted, abrasive 11 is applied to the circumferential surface of a ring-
shaped
abrasive backing 12. The outer surface of abrasive backing 12 is adapted to
the
outline of the moldings to be sanded. The inner outline or the inside diameter
remains
the same for all abrasive backings 12. Abrasive backing 12 is stuck onto a pad
holder
13, which is fabricated from a flexible or plastic material, preferably sponge
rubber.
Pad holder 13 is made up of a cylindrical ring 13a and a support ring 13b,
which is
attached to one frontal end. If sanding tool 10 is driven in rotation about a
vertical
axis, support ring 13b lies at the bottom. On the side facing toward the outer
surface
of cylindrical ring 13, support ring 13b is provided with a groove 14 into
which a
corresponding projection of abrasive backing 12 engages. Because ofthe special
fashioning of pad holder 13, it can be used for all forms of abrasive backing
12. Pad
holder 13 is mounted in torsionally rigid fashion on a frame 15, which can be
stuck
onto the shaft of a sanding machine in torsionally rigid fashion. In the
exemplary
embodiment depicted, frame 15 is made up of a hub 15a, a seat ring 15b
standing
concentrically thereto, and an end ring 15c connecting hub 15a to seat ring
15b.
Frame 15 is fabricated from metal, for example steel or aluminum.
In contrast to the embodiment depicted, support ring 13b could also have a
larger diameter and extend into the region of the outer edge of abrasive 11.
Preferably,
however, the outer surface of support ring 13b is at a short distance from the
edge of
abrasive 11. Further, it would be conceivable that the outer edge of abrasive
11 either
rests on a terminating ring or abuts the inner surface. This terminating ring
lies offset
relative to support ring 13b, that is, offset in the direction toward the end
surface of
sanding tool 10 that faces away from support ring 13b. Such designs stabilize
abrasive
CA 02437879 2003-08-08
4
11 in the region of curves or radii. It is further conceivable that the
abrasive backing is
modeled cylindrically and that a void arises in the region of the curve of
abrasive 11
between support ring 13b, abrasive backing 12 and abrasive 11, which void is
then
filled with air.
The embodiment depicted should be regarded as an example. Alternatively, it
is also possible for sanding tool 10 to be a segmental sanding wheel in which
the
frame can be integral or multi-sectioned and have a plurality of segments on
which a
corresponding number of pad segments can then be mounted. The abrasive
backings
are then fastened to these pad segments, which once again are of identical
construction for all moldings to be sanded. Further, it is possible for pad
holder 13 to
have a circumferential surface fashioned in the manner of segments, only the
raised
regions being faced with the abrasive seats. The invention is not limited to
the
exemplary embodiments mentioned. What is essential is that molding-dependent
abrasive seats 12 are mounted on pad holders or pad segments of identical
construction.
