[0001] This invention relates to an improved sander machine, preferably for sanding panels
made of wood, composite materials, metals, Corian, stone or glass.
[0002] More in detail, the invention relates to a sander machine for the surface treatment
of workpieces, for hiding as much as possible the signs and deformities present on
the external surfaces of the workpieces, in order to render them as uniform as possible.
[0003] More specifically, the machine according to the invention is particularly effective
when processing wooden items formed by several slats coupled together in directions
incident with each other.
[0004] In fact, in these cases, the machine is able to effectively "mask" the discontinuities
of the rough item, due basically to the various directions of the grains of the wood,
giving the article a more homogeneous appearance.
[0005] The description below relates to sander machine for sanding wooden panels, but it
is quite apparent how the same should not be considered limited to this specific use,
as it may also be used, as mentioned above, for sanding workpieces of different shape
and type.
[0006] Machines are known for sanding surfaces of workpieces which, however, in many cases
are not able to fully perform the function for which they are designed.
[0007] In fact, if the machines of known type are used for sanding workpieces with particularly
pronounced surface marks, they are not normally able to effectively hide the marks,
leaving the latter clearly visible even to the naked eye.
[0008] In light of the above, the aim of the invention is therefore to provide an improved
sander machine which is able to effectively render uniform the external surfaces of
the workpieces.
[0009] Another aim of the invention is to provide a sander machine which has fast execution
times for the planned sanding.
[0010] Therefore, this invention specifically relates to a sander machine for sanding workpieces
or elements made of wood or other materials, configured for being mounted in a supplying
line for supplying elements or workpieces according to an advancing direction, said
sander machine comprising: at least a frame, a first sanding unit comprising a base
configured for oscillating in translation along a predetermined direction, at least
one support connected to said base in such a way as to be rotatable, in use, about
a first axis substantially vertical, a least one sander member for sanding, in use,
at least one surface of an element or workpiece transported by said supplying line,
said sander member being mounted on said at least one support so as to be rotatable,
in use, about a second axis substantially parallel to said first axis, and first motor
means for actuating said base, said at least one support and said at least one sander
member; and a second sanding unit comprising an abrasive element for abrading, in
use, at least one surface of an element or workpiece transported by said supplying
line, a first movement system equipped with at least one first eccentric member rotatable,
in use, about an axis substantially vertical and connected to said abrasive element
in such a way that the rotation of said at least one first eccentric member causes
a movement of said abrasive element according to an orbital trajectory on a predetermined
plane, and second motor means for actuating said at least one eccentric member.
[0011] Preferably, according to the invention, said predetermined direction is substantially
at right angles to said advancing direction.
[0012] Further, according to the invention, said at least one support and said at least
one sander member can rotate, in use, in the same or opposite directions.
[0013] Preferably, according to the invention, said first sanding unit comprises four sander
members positioned substantially equidistant from each other.
[0014] Advantageously, according to the invention, said second sanding unit can comprise
a second movement system equipped with at least one second eccentric member connected
to said abrasive element and rotatable, in use, about a substantially vertical axis
according to a circular trajectory narrower than a circular trajectory of rotation
of said at least one first eccentric member.
[0015] Moreover, according to the invention, said abrasive element can comprise a substantially
flat abrasive surface.
[0016] Advantageously, according to this invention, said second sanding unit can be positioned,
in use, downstream of said first sanding unit with respect to said advancing direction.
[0017] Further, according to this invention, said first sanding and said second sanding
unit can be positioned mutually adjacent with respect to said advancing direction.
[0018] The invention is now described, by way of example and without limiting the scope
of the invention, with reference to the accompanying drawings which illustrate preferred
embodiments of it, in which:
Figure 1 is a partial perspective view of the sander machine according to the invention;
Figure 2 is a partial side view of the machine shown in Figure 1;
Figure 3 shows, partially, a first operating unit of which the machine shown in Figures
1 and 2 is composed; and
Figure 4 shows, schematically, the general operating principle of a second operating
unit of the machine illustrated in Figures 1 and 2.
[0019] In the various figures similar parts are labelled with the same reference numerals.
[0020] With reference to the accompanying drawings, the numeral 1 denotes in its entirety
a sander machine according to the invention.
[0021] The sander machine 1 comprises, in particular, a supplying line 2, in turn comprising
a conveyor belt 3, for transporting the panels to be sanded along an advancing direction
A.
[0022] The sander machine 1 also includes a first sanding unit 4 for carrying out on the
panels a first coarser sanding operation.
[0023] The first sanding unit 4, of per se known type, comprises a first frame 5 inside
of which there is a first operating unit 6 equipped with, in the relative lower part,
a base 7 oscillating in translation according to a direction substantially at right
angles to the advancing direction A.
[0024] On the lower side of the base 7 is fitted, in a rotatable fashion, a plurality of
circular supporting plates 8, aligned with each other transversally to the advancing
direction A.
[0025] Each plate of said plurality of supporting plates 8 is rotatable about a respective
vertical axis passing through the relative centre and is rotatable by means of a motor.
[0026] Moreover, on each plate of the plurality of supporting plates 8 are fitted, underneath,
four sander members 9, which are also circular, positioned at an equal angular distance
from each other and, in turn, rotatable about the relative axes with respect to the
relative plate 8.
[0027] The sander members 9 each have a substantially flat abrasive bottom, facing the underlying
conveyor belt 3 and designed to come into contact with the upper surface of the panels
positioned above the conveyor belt 3.
[0028] The sander members 9 are also connected to a motor designed to rotate them, in one
direction or in the opposite direction, about the relative vertical axis.
[0029] Downstream of the first sanding unit 4 there is, in a position adjacent to the latter,
a second sanding unit 10, also this of a
per se known type (for example, such a second sanding unit 10 is described in international
patent application no.
PCT/US91/05849) which performs the specific function of carrying out a fine sanding, that is to
say, less coarse than that performed by the first sanding unit 4, in order to further
improve the surface finish of the panels.
[0030] The second sanding unit 10 is supported by a relative frame 11 and comprises, in
the relative lower part, an orbiting support or element 12 with a substantially rectangular
shape, positioned transversally to the advancing direction A and coated on the underside
with an abrasive element or substance 13, such as, for example, an abrasive paper,
facing the conveyor belt 3.
[0031] For the movement of the orbiting support or element 12 on a plane parallel to the
conveyor belt 3 there is a first movement system 14 and a second movement system 15.
[0032] The first movement system 14 includes a first pair of lateral operating units 16a,
16b which comprise, in turn, respective eccentric members 17a, 17b connected to the
orbiting support or element 12 and which can be rotated by an electric motor.
[0033] The second movement system 15 comprises, on the other hand, in the space between
the of the operating units of the above-mentioned first pair of operating units 16a,
16b, a second pair of operating units 18a, 18b also equipped with respective eccentric
members 19a, 19b connected to the orbiting support or member 12 and to a second electric
motor designed to rotate them about the respective axes.
[0034] Specifically, the rotary movements of the operating units of the second pair of operating
units 18a, 18b follow circular trajectories which are narrower than those described
by the operating units of the first pair of operating units 16a, 16b, in such a way
that the orbiting support or element 12 carries out, in fact, a complex movement,
according to an orbital trajectory, resulting from the combination of two rotations,
that is, a first rotation, which is fast and with a short radius, caused by the second
movement system 15 and a second rotation, which is slower and with a larger radius,
determined by the action of the first movement system 14.
[0035] More specifically, the faster and narrower movement allows the transversal scoring
to be eliminated from the panels, as it produces a sanding free of any preferential
abrasion direction; on the other hand, the second rotation, which is slower and wider,
renders the abrasion homogeneous over the entire sanding area.
[0036] The orbiting support or element 12 of the second sanding unit 10 is therefore able
to reproduce on the workpiece to be sanded the same movement which would be performed
by a manual orbiting platen actuated by a skilled operator.
[0037] During the operation of the sander machine 1, the panels transported by the conveyor
belt 3 according to an advancing direction A pass, initially, beneath the first sanding
unit 4 where they undergo a first sanding operation by the sanding members 9, which
contribute to conferring to the upper surface of the panels a first degree of finish
thanks to the multi-directional action generated by the rotation of the sander members
9, by the rotation of the supporting plates 8 and by the translational oscillating
movement of the base 7 on which the latter are mounted.
[0038] After undergoing the sanding action of the first sanding unit 4, the panels are transported,
by the conveyor belt 3, beneath the second sanding unit 10 where they undergo a further
sanding which is even finer.
[0039] In fact, once a predetermine panel has reached the position beneath the second sanding
unit 10, the orbiting support or element 12, which is already at the same level of
the upper surface of the panel or which lowers until reaching it, starts the second
sanding operation, during which the surface is finely sanded thanks to the above-mentioned
complex movement of the orbiting support or element 12 and of the underlying abrasive
element or substance 13.
[0040] Surprisingly, it has been found that the combination of the two sanding operations
performed by the first 4 and by the second 10 sanding units produces considerable
effects on the workpieces sanded in terms of uniformity and quality of the surface
finish obtained.
[0041] This invention is described by way of example only, without limiting the scope of
application, according to its preferred embodiments, but it shall be understood that
the invention may be modified and/or adapted by experts in the field without thereby
departing from the scope of the inventive concept, as defined in the claims herein.
1. Sander machine (1) for sanding workpieces or elements made of wood or other materials,
which is configured to be mounted in a supplying line (2) for supplying elements or
workpieces according to an advancing direction (A), said sander machine (1) comprising:
at least one frame (5, 11),
a first sanding unit (4) comprising:
a base (7) which is configured to oscillate in translation along a predetermined direction,
at least one support (8) which is connected with said base (7) such as to be rotatable,
when in use, about a first axis which is substantially vertical,
at least one sander member (9) for sanding, when in use, at least one surface of a
element or a workpiece being transported by said supplying line (2), said at least
one sander member (9) being mounted on said at least one support (8) such as to be
rotatable, when in use, about a second axis which is substantially parallel to said
first axis, e
first motor means for activating said base (7), said at least one support (8) and
said at least one sander member (9); and
a second sanding unit (10) comprising:
an abrasive element (12, 13) for abrading, when in use, at least one surface of a
element or a workpiece being transported by said supplying line (2),
a first movement system (14) which is provided with at least one eccentric member
(17a, 17b) which is rotatable, when in use, about a substantially vertical axis and
connected with said abrasive element (12, 13) such that the rotation of said at least
one eccentric member (17a, 17b) causes said abrasive element (12, 13) to move according
to an orbital trajectory on a predetermined plane, and
second motor means for activating said at least one eccentric member (17a, 17b).
2. Sander machine (1) according to claim 1, characterized in that said predetermined direction is substantially orthogonal with respect to said advancing
direction (A).
3. Sander machine (1) according to claim 1 or 2, characterized in that said at least one support (8) and said at least one sander member (9) rotate, when
in use, in the same sense or in senses being opposite to each other.
4. Sander machine (1) according to any one of the preceding claims, characterized in that said first sanding unit (4) comprises four sander members (9) which are placed substantially
equidistant to one another.
5. Sander machine (1) according to any one of the preceding claims, characterized in that said second sanding unit (10) comprises a second movement system (15) which is provided
with at least one second eccentric member (19a, 19b) which is connected with said
abrasive element (12, 13) and rotatable, when in use, about a substantially vertical
axis according to a circular trajectory which is narrower than a circular trajectory
for the rotation of said at least one first eccentric member (17a, 17b).
6. Sander machine (1) according to any one of the preceding claims, characterized in that said abrasive element comprises an abrasive surface (13) which is substantially flat.
7. Sander machine (1) according to any one of the preceding claims, characterized in that said second sanding unit (10) is placed, when in use, downstream from said first
sanding unit (4) with respect to said advancing direction (A).
8. Sander machine (1) according to any one of the preceding claims, characterized in that said first sanding unit (4) and said second sanding unit (10) are placed adjacent
to each other with respect to said advancing direction (A).