The present invention relates to a unit for feeding panels
of wood or the like.
In the wood panel machining sector, it is known to provide
a feeding unit comprising a lower loading surface for a panel to be fed to an operating
unit adapted to machine the panels and an upper unloading surface for receiving
the panel machined by the operating unit itself.
The two loading and unloading surfaces are substantially
horizontal and parallel to each other and are fixed to a rectilinearly reciprocating
mobile support frame in a vertical direction to move the loading surface between
a lowered position and a raised position for feeding the panel to be machined to
the operating unit and to move the unloading surface between a raised position and
a lowered position for receiving the machined panel from the operating unit.
Since the panels to be machined are loaded one at a time
onto the loading surface from a stack of panels arranged by the side of the feeding
unit, the known feeding units of the above-described type are relatively cumbersome,
require relatively large installation spaces and relatively high installation costs,
and introduce relatively long dead times.
It is an object of the present invention to provide a unit
for feeding panels of wood or the like which is free from the above-described drawbacks
and which is simple and cost-effective to implement.
According to the present invention, there is provided a
unit for feeding panels of wood or the like as claimed in claims from 1 to 11.
The present invention further relates to a method for feeding
panels of wood or the like.
According to the present invention, there is provided a
method for feeding panels of wood or the like as claimed in claims from 12 to 22.
A preferred non-limiting embodiment of the invention will
now be described by way of example with reference to the accompanying drawings,
- figure 1 is a diagrammatic side view, with parts removed for clarity, of a preferred
embodiment of the feeding unit of the present invention and of an operating unit
- figure 2 is a diagrammatic side view, with parts removed for clarity, of the
feeding unit of figure 1; and
- figure 3 is a diagrammatic side view, with parts removed for clarity, of a detail
of figure 2.
With reference to figure 1, numeral 1 indicates as a whole
a feeding unit for feeding panels 2 of wood or the like to be machined to an operating
unit 3 of known type and to receive the machined panels 2 from unit 3 itself.
Unit 3 is connected to unit 1 at an inlet station 4 having
a resting surface P1 for panels 2, and comprises an elongated base 5, which extends
in a certain direction 6, and is limited on top, in the case in point, by a supporting
panel (not shown), which is commonly called a "sacrificial board", is fastened to
base 5, is substantially coplanar with surface P1, and is made of air permeable
material so as to allow the locking of panel 2 onto surface P1 itself.
Unit 3 further comprises a gantry 7 comprising, in turn,
a vertical pillar (not shown), which is coupled in known manner to base 5 to perform
rectilinear movements in direction 6, along base 5 itself and under the bias of
an actuating device (known and not shown), and carries a horizontal crossmember
8 connected thereto and extending over base 5 in a direction 9 transversal to direction
6 and perpendicular to the sheet plane in figure 1.
Gantry 7 supports an operating head 10, which is coupled
in a known manner to crossmember 8 to perform, along crossmember 8 itself, rectilinear
movements in direction 9, and normally comprises at least one spindle of a known
type and not shown, which is mounted on operating head 10 itself to be moved in
a direction 11 vertical and orthogonal to directions 6 and 9, and is mobile over
base 5 to allow a corresponding tool (not shown) fitted on the spindle (not shown)
itself to obtain from each panel 2 a plurality of panels (not shown) of smaller
dimensions than those of panel 2 itself.
As shown in figure 2, unit 1 comprises four vertical pillars
12 (only two of which are shown in figure 2), each of which extends in direction
11 and is aligned to the two adjacent pillars 12 in directions 6 and 9.
Pillars 12 support a lower supporting plate 13, which extends
between pillars 12, defines a lower loading surface P2 substantially horizontal
and orthogonal to direction 11, is adapted to support a stack 14 of panels 2 reciprocally
overlapping in direction 11, and is slidingly coupled to pillars 12 to perform rectilinear
movements in direction 11 itself, with respect to pillars 12 themselves and under
the bias of an actuating device 15.
Plate 13 presents a substantially rectangular shape, and
supports four scrolls 16 at its vertexes, each of which is coupled, by means of
a screw/nut-screw coupling, to a corresponding screw 17 of device 15, a motor of
which (of known type and not shown) puts screws 17 into rotation by means of a chain
drive 18 of a known type to give rectilinear movements in direction 11 to scrolls
16 and thus to plate 13.
Unit 1 further comprises an upper supporting plate 19,
which extends between two pillars 12, defines an upper unloading surface P3 substantially
parallel to surface P2, and is slidingly coupled to pillars 12 to perform rectilinear
movements in direction 11 with respect to pillars 12 and according to modalities
which will be illustrated in greater detail below.
Plate 19 is normally maintained in a lowered position (figure
2), in which surface P3 is substantially coplanar with surface P1, by means of four
supporting blocks 20 mounted on pillars 12 to support the bottom of plate 19 itself.
Plate 19 is mobile from its lowered position to a first
raised position (figure 3), in which the distance between plate 19 and surface P1
of inlet station 4 of operating unit 3 approximates by excess the total height of
panels 2 which must be fed from time to time onto surface P1 itself, and is adapted
to be locked in its first raised position by means of a stop assembly 21.
With reference to figure 3, assembly 21 comprises a plurality
of stop devices 22 (four stop devices 22 in the case in point), each of which is
associated to a corresponding pillar 12, and comprises a rocker arm 23 hinged to
plate 19 to oscillate, with respect to plate 19 and under the bias of an actuator
cylinder 24, about a fulcrum axis 25 substantially parallel to direction 9.
Cylinder 24 presents an outlet rod 26, which is hinged
to a first arm 27 of rocker arm 23, and is mobile between a retracted position (figure
3), in which rod 26 moves a second arm 28 of rocker arm 23 to a fastening position
of a supporting block 29 fixed to corresponding pillar 12, and an extracted position
(not shown), in which rod 26 moves arm 28 to a release position from block 29 itself.
Plate 19 is further mobile in a second raised position
arranged over the first raised position, and is adapted to be locked in its second
raised position by means of four devices 22, each of which cooperates with a supporting
block 30 fastened to corresponding pillar 12 over a corresponding block 29.
Plate 19 is finally provided with a transfer assembly 31,
which feeds panels 2 of stack 14 in direction 6, and cooperates with a gripping
and conveying assembly of known type associated to crossmember 8 of operating unit
3 to complete the transfer of panels 2 themselves onto surface P1.
Assembly 31 comprises at least one actuator cylinder 32,
which is fixed to plate 19 parallelly to direction 6, and presents a telescopic
outlet rod 33 on which there is mounted a bar 34, which extends in direction 6,
and supports a plurality of transfer devices 35 distributed along bar 34 itself.
Each device 35 comprises a crank 36, which is hinged to
bar 34 to oscillate in a known manner, with respect to bar 34 itself, about an axis
37 of fulcrum substantially parallel to direction 9 between a raised rest position
and a lowered operative position, is provided with a supporting wheel 38 adapted
to be arranged in contact with upper panel 2 of stack 14, and is further provided
with a pushing element 39 adapted to engage the rear edge of panels 2 to be transferred
onto surface P1.
The operation of unit 1 will now be described assuming
the feeding, the machining and the unloading of a single panel 2 from the moment
- lower plate 13 is arranged in a lowered position (figure 2);
- one stack 14 of panels 2 is loaded on lower loading surface P2;
- upper plate 19 is arranged in its lowered position (figure 2);
- outlet rod 33 of actuator cylinder 32 is arranged in a retracted position (not
- transfer devices 35 are arranged in their raised rest positions;
- outlet rods 26 of actuator cylinders 24 are arranged in their extracted positions;
- stop devices 22 are arranged in their release positions.
Lower plate 13 is raised by means of actuating device 15
and from its lowered position to firstly move upper panel 2 from stack 14 into contact
with a plurality of supporting pads 40 protruding downwards from upper plate 19
to thus raise plate 19 itself from its lowered position to its first raised position.
At this point, outlet rods 26 of actuator cylinders 24
are moved into their retracted positions and stop devices 22 are moved into their
fastening positions so as to lock plate 19 in its first raised position; plate 13
is lowered again by means of actuating device 15 and stopped in a raised position
(not shown), in which panel 2 to be transferred onto surface P1 is substantially
coplanar with surface P1 itself.
The transfer of panel 2 considered on surface P1 is performed
by firstly moving transfer devices 35 into their lowered operative positions so
as to rest wheels 38 on panel 2 and thus moving outlet rod 33 of actuator cylinder
32 into its extracted position to allow one of pushing elements 39 to engage the
rear edge of panel 2 and to advance panel 2 itself in direction 6 and on surface
According to a variant (not shown), transfer devices 35
are normally arranged in their lowered operative positions. When plate 13 is raised,
some transfer devices 35 are engaged by upper panel 2 of stack 14 and are thus moved
into their raised rest positions, while the remaining transfer devices 35 remain
in their lowered operative positions to feed panel 2 in direction 6.
During the machining of the considered panel 2 by operating
unit 3, plate 13 is firstly raised in direction 11 from its raised position so as
to move the new upper panel 2 of stack 14 into contact with pads 40 and to allow
the release of plate 19 from supporting blocks 19 and is thus lowered again to move
plate 19 itself into its lowered position.
After ending the machining, machined panel 2 is unloaded
in a known manner onto surface P3 and the above-described operative sequence is
repeated to feed panels 2 to be machined from surface P2 onto surface P1 and to
unload newly machined panels 2 from surface P1 to surface P3.
When all panels 2 from stack 14 have been machined by operating
unit 3 and unloaded by feeding unit 1, plate 19 is moved by means of plate 13 to
its second raised position to allow a feeding carriage of a known type and not shown
to be arranged between plates 13 and 19 to load a new stack 14 of panels 2 onto
lower surface P2.
From the above, it is understood that the second raised
position of plate 19 depends on the maximum height of stack 14 of panels 2 which
must be loaded onto lower surface P2.
According to a variant (not shown), feeding unit 1 further
comprises a cavity which is obtained underneath pillars 12, opens outwards at the
ground, and is adapted to accommodate therein stacks 14 of panels 2 presenting heights
higher than the length of pillars 12 themselves. In this case, once stack 14 is
loaded on surface P2, plate 13 is lowered into the cavity so as to lower upper panel
2 of stack 14 to a position substantially coplanar with surface P1 and to start
feeding of panels 2 to operating unit 3.
As plate 19 may be locked into two fixed raised positions
in direction 11 and plate 13 is mobile with respect to plate 19 with a law of motion
at least partially different from the law of motion of plate 19 itself, it must
be said that:
- the lowered position of plate 13 is variable in direction 11 and its height
from the ground gradually increases as panels 2 from stacks 14 arranged from time
to time on surface P1 are fed to operating unit 3; and
- the length of the outward and return strokes of plate 13 between its lowered
position and its raised position gradually decrease as panels 2 of stack 14 are
fed to operating unit 3 introducing relatively short dead times.
According to a variant (not shown), plate 19 is mobile
between its raised positions and its lowered position under the bias of a lifting
device entirely independent from plate 13 and device 15 and according to a law of
motion entirely independent from the law of motion of plate 13 itself.
Feeding unit 1 thus presents relatively small dimensions
and considerably reduces the interventions of personnel responsible of controlling
units 1 and 3.