Background of the invention
[0001] The invention relates to an operating unit according to the preamble of claim 1.
[0002] Specially, but not exclusively, the invention can be advantageously used in an edgebanding
machine for operating on a workpiece, for example in the shape of a panel. In particular,
the invention can be used for performing at least one machining on an edge of a workpiece
to which a laminar edge element has been applied (machining can comprise, for example,
trimming the edge, scraping the edge, scraping the glue, etc), more in particular
when a tool has to follow the edge of a panel provided with one or more recessed or
lowered zone, such as, for example, the recessed seats for housing the hinges in a
panel intended for forming a piece of furniture.
[0003] When edgebanding a workpiece - in particular a panel-shaped workpiece (such as, for
example, a wall, a hatch, a door, a shelf) made of wood or a composite wood-based
material or another material that is similar to wood - a laminar element is applied
to one or more edges of this workpiece.
[0004] In general, after the laminar element has been applied to the edge of the workpiece
by gluing, subsequent machinings are performed to remove material. Particularly, such
machinings can be performed by a trimming unit for trimming the laminar element with
respect to the workpiece by removing the excess material from the workpiece and/or
by an edge-scraping unit to finish the connection between the laminar element and
the workpiece and/or by a glue scraping unit to eliminate glue residues.
[0005] Each known operating unit is associated with an edgebanding machine - in particular
a trimming unit or an edge scraping unit or a glue scraping unit - generally comprises
a tool set up for removing material from the workpiece. For example, the tool of the
trimming unit is in general a milling unit that can be, for example, of the radiating
type, having a radius of curvature equal to the connecting radius of the trimmed laminar
element.
[0006] Each operating unit further comprises a copying device that guides the tool to follow
the profile of the element to be trimmed and/or scraped by means of contact between
one or more surfaces of the copying device with the workpiece and/or with the laminar
element.
[0007] In use, the trimming and scraping operations are performed during a workpiece edgebanding
process. If the workpiece is, for example, a hatch, door or shelf, i.e. a workpiece
that has to be mounted on other elements to form a piece of furniture, the workpieces
can have a plurality of recesses or lowered zones arranged in an end portion of at
least one face of the workpieces. Such zones can comprise holes made to receive fixing
elements (for example threaded screws) and/or breaks for housing hinges. In general,
the end portion that has the recessed or lowered zones is adjacent to one of the edges
to which the laminar edge element has to be applied.
[0008] Generally, the plurality of recessed or lowered zones is arranged along the path
of the copying device that operates on the workpiece. Thus, when a lowered zone is
below the copying device, the latter can be lowered to cause consequently lowering
of the entire operating unit, and thus also of the tool, with respect to the workpiece.
This entails a risk of damage to the workpiece and of significant machining imprecision.
The workpiece, for example, can be damaged because the cutting parts of the tool no
longer operate on the connection between the laminar element and the workpiece, but
in a lower position, thus removing an excessive quantity of material.
[0009] Italian patent application ITMO
20090127A1, in the name of the applicant, discloses an operating unit which offers a solution
to the aforesaid problem. Certain aspects of this known operating unit can be improved.
[0010] GB 1 044 483 A discloses an operating unit made according to the preamble of claim 1.
Summary of the invention
[0011] One object of the invention is to make an operating unit with a copying device that
is able to machine a workpiece with great precision.
[0012] One advantage is to provide an operating unit of great reliability and high productivity.
[0013] One advantage is to make available an operating unit, in particular for an edgebanding
machine, of great flexibility, that is, for example, able to perform machinings, such
as trimming and/or scraping the edges of a workpiece, also near zones of the workpiece
in which there are holes, cavities, lowered zones or other recesses with respect to
the flat surface of the workpiece.
[0014] One advantage is to enable the edge of a workpiece to be trimmed and scraped even
after holes or cavities or lowered zones have been made on end portions of the workpiece,
thus with the possibility of ample freedom in setting the desired machining cycle.
[0015] One advantage is to decrease the cost of producing workpieces having at least one
edge to which a laminar element is applied to cover the edge itself.
[0016] One advantage is to provide an operating member and/or an edgebanding machine and/or
a copying device that is able to machine a wide range of workpieces, including workpieces
such as, for example, hatches, doors, shelves, panels, on which holes, cavities, lowered
zones or other zones are obtained that are recessed with respect to a flat surface
of the workpiece, near at least one edge thereof.
[0017] Such objects and advantages, and still others, are achieved by the operating unit
according to one or more of the claims set out below.
Brief description of the drawings
[0018] The invention can be better understood and implemented with reference to the enclosed
drawings that illustrate some embodiments thereof by way of non-limiting example.
Figure 1 is a perspective view of a copying device made according to the invention
for an operating unit for machining a panel.
Figure 2 is a perspective view of an operating unit comprising the copying device
in figure 1.
Figure 3 is the section view in figure 2.
Figure 4 is a side view of the section in figure 3.
Figure 5 is a perspective view of the operating unit in figure 2 without the copying
device.
Figure 6 is a vertical raised side view of an edgebanding machine having a glue-scraping
operating unit made according to the invention.
Figure 7 is a perspective view of the glue-scraping operating unit of the machine
in figure 6.
Figure 8 is a side view of the glue-scraping operating unit in figure 7.
Detailed description
[0019] With reference to the aforesaid figures 1 to 5, with 1 an operating unit for machining
a workpiece 2 made of wood or a similar material has been indicated overall. The operating
unit 1 may comprise, as in this case, a trimming unit for trimming the edge of a workpiece
to which a laminar covering element has been previously applied. The operating unit
1 may be included in an edgebanding machine for edgebanding the workpiece. The workpiece
2 being machined may comprise, as in this case, a panel having at least one flat (upper)
surface that has one or more recessed or lowered zones such as, for example, a break
3 that defines a housing seat of a hinge for furniture.
[0020] The operating unit comprises at least one tool 4 for performing a machining on the
workpiece. This tool 4 may comprise, as in this case, a trimming miller of the edge
of the workpiece 2.
[0021] During the machining there is a relative supplying movement between the tool 4 and
the workpiece 2 in a supplying direction F parallel to the flat surface of the workpiece
2. The edgebanding machine will be provided with movement means, of substantially
known type (which is for this reason not disclosed in detail) to provide the aforesaid
supplying movement. In the specific case, the supplying movement is supplied to the
workpiece 2 that advances on a (horizontal) conveying or advancing plane in the direction
F.
[0022] The operating unit 1 is provided with supporting means, indicated overall with 5,
for supporting the tool 4 during machining on the workpiece 2.
[0023] The operating unit 1 comprises a copying device 6 for following at least one profile
of the workpiece 2 being machined. The supporting means 5 on which the tool 4 is fitted
is connected to the copying device 6 in such a manner as to position the tool 4 in
the desired work configuration in relation to the workpiece 2 being machined.
[0024] The copying device 6 comprises, as in the case in point, two (or more) feeling wheels
7 that are able to interact simultaneously in contact with the flat surface of the
workpiece 2 being machined.
[0025] The feeling wheels 7 are arranged substantially one after the other in the supplying
direction F and rotate around two distinct rotation axes that are parallel and suitably
spaced apart from one another in the supplying direction F. The distance between the
two wheels 7 in direction F is preset. This distance has to be, in particular, greater
than the dimension (considered in the supplying direction F) of a recessed or lowered
zone on the flat surface of the workpiece being machined. In the case in point the
wheels 7 are exactly aligned one after the other in the supplying direction F, although
it is possible to provide a staggered arrangement. In this case, the wheels 7 are
arranged above the conveying plane on which the workpiece 2 being machined advances
in a direction F. The wheels 7 are arranged, in the case in point, for contact with
the (flat) upper surface of the workpiece 2 being machined. The wheels 7 are rotatably
coupled (in an idling manner) on the same supporting body. The two wheels 7 may have,
as in the case in point, the same diameter.
[0026] The two wheels 7 are shaped and arranged in such a manner as to define a contact
line (parallel to the supplying direction F of the workpiece 2 with respect to the
tool 4), i.e. the line that unites the lower edges of the two wheels 7 in which contact
with the workpiece 2 occurs.
[0027] The copying device 6 comprises a movable supporting element 8 on which the feeling
wheels 7 are rotatably mounted.
[0028] The supporting element 8 is connected to a (fixed) frame 9 with the constraint of
performing straight movements with at least one (vertical) component of motion perpendicular
to the (horizontal) flat surface of the workpiece 2 being machined. In particular,
the supporting element 8 of the wheels 7 is in turn supported by the frame 9 by means
of at least one articulated connection that is suitable for constraining the supporting
element 8 to perform, with respect to the frame 9, movements (translations) both in
a direction parallel to the supplying direction F, and in a direction perpendicular
to the flat surface of the workpiece. The frame 9 may support, as in this case, the
supporting element 8 of the wheels 7 by means of the interposition of an articulated
parallelogram connecting structure that enables the supporting element 8 to perform
the aforesaid movements (translations).
[0029] The supporting element 8 comprises, as in this case, a contact surface 10 that is
flat (horizontal) and parallel to the flat surface of the workpiece 2. The supporting
element 8 will in particular be constrained to perform translations in such a manner
as to maintain the contact surface 10 parallel (horizontal) to itself. The supporting
means 5 of the tool 4 comprises, as in this case, at least one contact element 11
arranged in a resting relationship on the contact surface 10. The tool 4 adopts a
preset work position with respect to the workpiece being machined when the contact
element 11 interacts in contact with (resting on) the contact surface 10. The contact
element 11 is placed in contact above the contact surface 10. The contact surface
10 thus has the function of being a reference element to enable the tool 4 to be positioned
correctly (carried by the supporting means 5) with respect to the workpiece 2 (which
is felt by contact by the feeling wheels 7).
[0030] In the case in point the (flat and horizontal) contact surface 10 is interposed between
two connecting rods 12 that are opposite and parallel to one another that are part
of the articulated parallelogram of the aforesaid connecting structure. With 13 the
articulations of the articulated parallelogram have been indicated. The supporting
element 8 is articulated at the two connecting rods 12 in such a manner that the contact
surface 10 is parallel to the direction defined by the other two mutually opposite
elements of the articulated parallelogram (articulated at the connecting rods 12)
that are substantially constituted by the movable supporting element 8 and by the
(fixed) frame 9.
[0031] The contact element 11 may comprise, as in the case in point, scraping means that
can in turn comprise at least one sliding contact zone for scraping and brushing away
dust or sawdust from the contact surface 10 through the (translation) movement of
the supporting element 8. In the case in point the contact element 11 is rotationally
coupled with the supporting means 5 around a pivot X with a, for example, horizontal
rotation axis. The contact element 11 can have, for example, two sliding (scraping)
contact zones arranged on opposite sides to the aforesaid pivot X. The contact element
11, that in the case in point is made in the shape of a slidable slide with one or
two or more scraping blades 14 (two in this case), that can nevertheless be made in
other shapes, for example in the shape of a bearing or of another rotatable element
(which is possibly also provided with scraping means). The contact element 11 may
be made of a material (for example in polyzene) that is suitable for ensuring over
time effective sharpening of the scraping blades 14.
[0032] In use, the workpiece 2 is supplied in a direction F towards the operating unit 1,
such that the tool 4 can machine the entire edge of the workpiece 2. During machining,
the workpiece 2 is guided, in a known manner, along the (horizontal) conveying plane,
whilst the tool 4 is maintained in the desired position with respect to the workpiece
2 (which in the meantime is supplied with the supply motion) owing to the copying
device 6. In fact, the feeling wheels 7 touch (both simultaneously or almost simultaneously)
the upper flat surface of the workpiece 2, so the contact surface 10 remains in a
parallel position to the workpiece 2. The supporting means 5 interacts with the contact
surface 10 (by means of the resting relation of the contact element 11) so that the
tool 4 (connected to the supporting means 5) adopts the correct work position. When
the break 3 (or other recess or lowered zone that the workpiece 2 may have) reaches
the operating unit 1, the tool 4 maintains the correct work position, even if one
wheel 7 loses contact with the upper flat surface of the workpiece 2 because it meets
the break 3. There is in fact the other wheel 7 that, being arranged at the appropriate
distance from the wheel that has lost contact, maintains contact with the workpiece
2. The supporting element 8, which thus always rests on the workpiece 2 with at least
one feeling wheel 7, does not suffer movements such as to compromise correct positioning
of the tool 4 with respect to the workpiece 2, because the supporting element is constrained
to perform only translations according, in the case in point, to the coupling with
the fixed frame 9 by means of the parallelogram articulated structure. In substance,
the contact surface 10 does not suffer substantial movements.
[0033] With reference to figures 6 to 8 with 15 an edgebanding machine has been indicated
overall comprising an operating unit 16 that, in this case, is a glue scraping unit
that operates simultaneously both on an upper edge zone of the workpiece 2, and on
a lower edge zone. The operating unit 16 is provided, in this case, with two copying
devices 16 that are similar to those shown previously. For the sake of simplicity,
the similar elements have been indicated by the same reference symbol. In this case
the tool 4 will comprise a glue-scraping blade. Two tools 4 are provided of the glue-scraping
type that are arranged on two sides (one above and the other below) of the workpiece
2. In this case each tool 4 is fitted on the movable supporting element 8 of the respective
copying device.
[0034] The operating unit 16 comprises in this case an elastic element that is fixed to
the frame 9 and which, in the case in point, comprises an elastic element of pneumatic
type, like, for example, an actuator 17. The actuator 17 may comprise, as in the example,
an actuator of linear type. It is possible to provide an elastic element of other
type, for example an elastic element that uses the elasticity of a solid body. The
elastic element (in this case the actuator 17) is connected to the movable supporting
element 8 to make the above supporting element 8 perform movements having at least
one motion component in a normal (vertical) direction to the (horizontal) flat surface
of the workpiece 2. The glue-scraping blade will be mounted elastically with the possibility
of slight movements so as to keep itself always in contact with the workpiece to follow
scraping.
[0035] The edgebanding machine 15 will be provided with other elements (not disclosed in
detail) with which known edgebanding machines can be provided for edgebanding workpieces
made of wood or similar material, such as for example a (substantially horizontal)
conveying plane configured for receiving in a resting manner the workpiece and conveying
the workpiece.
[0036] In use, the workpiece 2 will be supplied to the glue-scraping operating unit 16.
Upon the arrival of the workpiece 2 the actuators 17 will move the respective supporting
elements 8 that take the tools to the workpiece (the upper tool will be moved downwards
and the lower tool will be moved upwards), until the two pairs of feeling wheels 7
(upper pair and lower pair), by meeting the (upper and lower) surfaces of the workpiece,
indicate that the desired (upper and lower) work position of the glue-scraping tools
has been reached.
[0037] It will be possible to provide the operating unit 16 with sensors that are suitable
for indicating that the feeling wheels 7 have made contact (for example force or other
types of sensors connected to the actuators 17).
[0038] Also in this case if a feeling wheel 7 meets a lowered zone of the (upper or lower)
flat surface of the workpiece, the other feeling wheel 7 of the pair of wheels can
remain in contact with this flat surface, so the movable tool-holding supporting element
8 is not moved and the glue-scraping tool remains in the correct work position.
1. Operating unit comprising:
- at least one tool (4) for performing a machining on a workpiece (2) having at least
one flat surface, wherein during machining there is a relative supplying movement
between said tool and the workpiece in a supplying direction (F) parallel to the flat
surface of the workpiece;
- a copying device (6) for following a profile of the workpiece being machined, said
at least one tool (4) being guided by said copying device to take up a desired position
with respect to the workpiece being machined, said copying device (6) having at least
two feeling wheels (7) that are able to interact in contact with the flat surface
of the workpiece being machined;
wherein said copying device (6) comprises a movable supporting element (8) on which said
at least two feeling wheels (7) are rotatably mounted, said supporting element (8)
being guided to perform movements with at least a first motion component perpendicular
to the flat surface of the workpiece (2) and at least a second motion component parallel
to said supplying direction (F);
characterized in that said supporting element (8) comprises a contact surface (10)
that is flat and parallel to the flat surface of the workpiece, said tool (4) being
carried by supporting means (5) having at least one contact element (11) arranged
in a sliding resting relationship in contact on said contact surface (10), said contact
surface (10) having the function of being a reference element to enable said tool
(4) to assume a preset machining position in relation to the workpiece (2) being machined
2. Operating unit according to claim 1, wherein said copying device (6) comprises a frame
(9) to which said supporting element (8) is connected by an articulated parallelogram
connecting structure that enables said supporting element (8) to perform said movements.
3. Operating unit according to claim 1 or 2, wherein said at least two feeling wheels
(7) are arranged substantially one after the other in the supplying direction (F)
and are rotatably mounted on said supporting element (8) around two distinct rotation
axes that are parallel and spaced apart from one another in the supplying direction
(F).
4. Operating unit according to claim 2 or 3, wherein said contact surface (10) is interposed
between two connecting rods (12) of the articulated parallelogram of said connecting
structure that are opposite and parallel one another, said supporting element (8)
being articulated on said two connecting rods.
5. Operating unit according to any preceding claim, wherein said contact element (11) comprises at least one scraping contact
zone (14) to eliminate dust or sawdust from said contact surface (10) through the
effect of the sliding due to the movement of said movable supporting element (8).
6. Operating unit according to claim 5, wherein said contact element (11) is rotatably coupled with said supporting means
(5) around a rotation axis (X), said contact element (11) having at least two scraping
contact zones (14) arranged on opposite sides of said rotation axis.
7. Operating unit according to any preceding claim, wherein said tool (4) is carried
by said movable supporting element (8) and wherein said copying device (6) comprises
at least one elastic element (17) arranged for enabling said movable supporting element
(8) to perform elastic movements in a direction that is perpendicular to the flat
surface of the workpiece (2) being machined.
8. Edge-banding machine (15) comprising at least one operating unit for machining on
a workpiece made of wood or of a material that is similar to wood, characterised in that said operating unit is made according to any preceding claim.
1. Bedieneinheit, umfassend:
- wenigstens ein Bearbeitungsgerät (4) zum Durchführen einer Bearbeitung eines Werkstücks
(2) mit wenigstens einer flachen Oberfläche, wobei es während der Bearbeitung eine
relative Zuführbewegung zwischen dem Bearbeitungsgerät und dem Werkstück in einer
Zuführrichtung (F) parallel zu der flachen Oberfläche des Werkstückes gibt;
- ein Nachformgerät (6) zum Folgen eines Profils des zu bearbeitenden Werkstücks,
wobei das wenigstens eine Bearbeitungsgerät (4) durch das Nachformgerät geführt wird,
um eine gewünschte Position bezüglich des zu bearbeitenden Werkstücks einzunehmen,
wobei das Nachformgerät (6) wenigstens zwei Tasträder (7) aufweist, die in Kontakt
mit der flachen Oberfläche des zu bearbeitenden Werkstückes interagieren können;
wobei das Nachformgerät (6) ein bewegbares Tragelement (8) umfasst, auf dem die wenigstens
zwei Tasträder (7) drehbar angebracht sind, wobei das Tragelement (8) geführt ist,
um Bewegungen mit wenigstens einer ersten Bewegungskomponente senkrecht zur flachen
Oberfläche des Werkstückes (2) und wenigstens einer zweiten Bewegungskomponente parallel
zur Zuführrichtung (F) auszuführen;
dadurch gekennzeichnet, dass das Tragelement (8) eine Kontaktfläche (10) umfasst, die flach und parallel zur flachen
Oberfläche des Werkstückes ist, wobei das Arbeitsgerät (4) von einem Tragmittel (4)
getragen wird, das wenigstens ein Kontaktelement (11) aufweist, das in einer Gleit-/Rastbeziehung
in Kontakt mit der Kontaktfläche (10) angeordnet ist, wobei die Kontaktfläche (10)
die Funktion eines Referenzelementes hat, um dem Arbeitsgerät (4) zu ermöglichen,
eine vorgegebene Bearbeitungsposition bezüglich des zu bearbeitenden Werkstücks (2)
einzunehmen.
2. Bedieneinheit nach Anspruch 1, wobei das Nachformgerät (6) einen Rahmen (9) umfasst,
an dem das Tragelement (8) durch eine angelenkte Parallelogrammverbindungsstruktur
verbunden ist, die dem Tragelement (8) ermöglicht, die Bewegungen auszuführen.
3. Bedieneinheit nach Anspruch 1 oder 2, wobei die wenigstens zwei Tasträder (7) im Wesentlichen
hintereinander in der Zuführrichtung (F) angeordnet sind, und auf dem Tragelement
(8) um zwei getrennte Drehachsen drehbar angebracht sind, die parallel und in der
Zuführrichtung (F) voneinander beabstandet sind.
4. Bedieneinheit nach Anspruch 2 oder 3, wobei die Kontaktfläche (10) zwischen zwei Verbindungsstangen
(12) des angelenkten Parallelogramms der Verbindungsstruktur eingefügt ist, die gegenüberliegend
und parallel zueinander sind, wobei das Tragelement (8) an den beiden Verbindungsstäben
angelenkt ist.
5. Bedieneinheit nach einem der vorhergehenden Ansprüche, wobei das Kontaktelement (11)
wenigstens einen Schabekontaktbereich (14) umfasst, um Staub oder Sägespäne von der
Kontaktfläche (10) durch die Wirkung des Gleitens aufgrund der Bewegung des bewegbaren
Tragelementes (8) zu entfernen.
6. Bedieneinheit nach Anspruch 5, wobei das Kontaktelement (11) um eine Drehachse (X)
drehbar mit dem Tragelement (5) gekoppelt ist, wobei das Kontaktelement (11) wenigstens
zwei Schabekontaktbereiche (14) aufweist, die an gegenüberliegenden Seiten der Drehachse
angeordnet sind.
7. Bedieneinheit nach einem der vorstehenden Ansprüche, wobei das Bearbeitungsgerät (4)
durch das bewegbare Tragelement (8) getragen ist, und wobei das Nachformgerät (6)
wenigstens ein elastisches Element (17) umfasst, das ausgestaltet ist, dem bewegbaren
Tragelement (8) das Durchführen elastischer Bewegungen in einer Richtung zu ermöglichen,
die senkrecht zu der flachen Oberfläche des zu bearbeitenden Werkstücks (2) ist.
8. Kanteneinfassungsmachine (15), die wenigstens eine Bedieneinheit zum Bearbeiten eines
Werkstückes umfasst, das aus Holz oder einem Material hergestellt ist, das holzähnlich
ist, dadurch gekennzeichnet, dass die Bedieneinheit nach einem der vorhergehenden Ansprüche ausgestaltet ist.
1. Unité d'usinage comprenant :
- au moins un outil (4) destiné à réaliser un usinage sur une pièce de travail (2)
possédant au moins une surface plane, dans laquelle pendant l'usinage il y a un mouvement
d'avance relatif entre ledit outil et la pièce de travail selon une direction d'avance
(F) parallèle à la surface plane de la pièce de travail ;
- un dispositif suiveur (6) destiné à suivre un profil de la pièce de travail en cours
d'usinage, ledit au moins un outil (4) étant guidé par ledit dispositif suiveur pour
adopter une position souhaitée par rapport à la pièce de travail en cours d'usinage,
ledit dispositif suiveur (6) possédant au moins deux roues de palpage (7) qui sont
aptes à interagir en contact avec la surface plane de la pièce de travail en cours
d'usinage ;
dans laquelle ledit dispositif suiveur (6) comprend un élément de support mobile (8)
sur lequel lesdites au moins deux roues de palpage (7) sont montées rotatives, ledit
élément de support (8) étant guidé pour effectuer des déplacements selon au moins
une première composante de déplacement perpendiculaire à la surface plane de la pièce
de travail (2) et au moins une seconde composante de déplacement parallèle à ladite
direction d'avance (F) ;
caractérisée en ce que ledit élément de support (8) comprend une surface de contact (10) qui est plane et
parallèle à la surface plane de la pièce de travail, ledit outil (4) étant porté par
des moyens de support (5) comportant au moins un élément de contact (11) agencé dans
une relation d'appui coulissant en contact sur ladite surface de contact (10), ladite
surface de contact (10) remplissant la fonction d'élément de référence pour permettre
audit outil (4) d'adopter une position d'usinage préréglée par rapport à la pièce
de travail (2) en cours d'usinage.
2. Unité d'usinage selon la revendication 1, dans laquelle ledit dispositif suiveur (6)
comprend un bâti (9) auquel ledit élément de support (8) est relié par une structure
de liaison à parallélogramme articulé qui permet audit élément de support (8) d'effectuer
lesdits déplacements.
3. Unité d'usinage selon la revendication 1 ou 2, dans laquelle lesdites au moins deux
roues de palpage (7) sont agencées sensiblement l'une après l'autre selon la direction
d'avance (F) et sont montées rotatives sur ledit élément de support (8) autour de
deux axes de rotation distincts qui sont parallèles et espacés l'un de l'autre selon
la direction d'avance (F).
4. Unité d'usinage selon la revendication 2 ou 3, dans laquelle ladite surface de contact
(10) est interposée entre deux bielles (12) du parallélogramme articulé de ladite
structure de liaison qui sont en regard et parallèles entre elles, ledit élément de
support (8) étant articulé sur lesdites deux bielles.
5. Unité d'usinage selon l'une quelconque des revendications précédentes, dans laquelle
ledit élément de contact (11) comprend au moins une zone de contact de raclage (14)
pour éliminer de la poussière ou de la sciure de bois de ladite surface de contact
(10) par l'effet du coulissement dû au déplacement dudit élément de support mobile
(8).
6. Unité d'usinage selon la revendication 5, dans laquelle ledit élément de contact (11)
est couplé en rotation avec lesdits moyens de support (5) autour d'un axe de rotation
(X), ledit élément de contact (11) comportant au moins deux zones de contact de raclage
(14) agencées sur des côtés opposés dudit axe de rotation.
7. Unité d'usinage selon l'une quelconque des revendications précédentes, dans laquelle
ledit outil (4) est porté par ledit élément de support mobile (8) et dans laquelle
ledit dispositif suiveur (6) comprend au moins un élément élastique (17) agencé pour
permettre audit élément de support mobile (8) d'effectuer des déplacements élastiques
dans une direction qui est perpendiculaire à la surface plane de la pièce de travail
(2) en cours d'usinage.
8. Plaqueuse de chants (15) comprenant au moins une unité d'usinage destinée à usiner
une pièce de travail réalisée en bois ou en un matériau qui est similaire au bois,
caractérisée en ce que ladite unité d'usinage est réalisée selon l'une quelconque des revendications précédentes.