Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Th-l~ inYention relate~ to an apparatu~ .~or
joining piece~ of laminar material and in particular
plywood core strips.
- ~lachines have been proposed which join together
wood strips intended ~or m~{ing up the co~e plies o~
plywood, or ve~eex strip~ in general, by applying
thereon the jointing material such as adhesive tapes
or threads in a perpendicular directio~ to the strip
edges~ a~d utilize a technique con~isting 1~ providing
a succession of entraining con~eyor floor~ hereon
the strips to be jointed edgewise are placed,and
~uitable pre~sure mechanisms capable o~ maintaining
~he strip~ in contact with such co~veyor ~loors; these
¢onve~or...~loors, which are compo~ed each of a serie~
o~ coplanar parallel con~eyor belts arranged in ~paced
~ide-b~side relatio~ship are characteristically driven
at decreasing speeds, thersby the e~tr~inment o~ the
wood strips to be joi~ted towards the jointing material
applying mean~ iB perîormed with a progre~sive slowi~g
20 down of the ~oremost strips and consequent contacting
therewith of the strips sequentially advanced from the
ieeding cenveyor ~loor ~o the subsequent crowding
co~veyor floor coplanar therewith.
E~own pre ssure mechanisms include pressing
conveyor ~loors arranged above the entraining conveyor
floors and adapted to press the wood strips against
the underlying conveyor floors.
An example ~or thls technique is described, ~or
example, i~ U5 Patent~ 2~705,514 or 2,4B8,759.
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T~e use o~ pres~ing conveyor $100rs of the above
d~scribed type had among others the ~ollowing
dra~back~:
a) The strips to be proce~sed were clamped between
the belts of the conveyor floor~ and e~rained by both
of them 80 that a sliding movem~nt between the strips
and the belts was dif~icult, thereby the ~rowding of
the strip~ at t~e ~lower advancing conveyor floor
wa~ e.ither impo3sible or caused excessive stresses both
on the strips and the conveyor belt~.
b) The pressing conveyor floors require a
complicated energy consumi~g driving and supporting
meohanism, which occupied precious ~pace above the
entraining conveyor floors, thereby preventing ade~uate
arrangement of devices for the transverse slignment
of the strips and the devices for the application of
the ~ointing material on the strips~ in addition to
the increased costs of the apparatus.
Thi~ invention is aimed at resolving the problems
inherent in the removal of the above indicated draw-
back~ from the apparatuses ~or joining pieces of
laminar material to bet~er the efficency, increa~e the
output and to reduce the manufacturing~ msi~tenance
and operational costs.
~or the purpose there is provided according to
the inve~tion sn apparatus for joining pieces of
lamin~-r material, in particular wooden strips for
! plywood cores, including a plurality of successiv0
¢oplanar oon~eyor iloors~ each consisting oi a series
3 of coplanar and parallel conveyor belt~ arr~lged in
spa¢ed side-by-side relation~hip, said plurality o~
~ucces~ive coplanar conveyor floors including at least
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one feeding conveyor ~loor and at least one crowding
con~eyor ~loor arr~nged a~ter the feeding conveyor
floor and ha~ing it~ conveyor belt~ moving at a speed
slower than that of the feeding conveyor ~loor belt~
S to allow the orowding thereon o~ the strip~ to be
joi~ed~ and pressure mechani~m3 for holding the ~trip~
in contact ~ith the convegor floors~ wherein according
to the improvement the apparatus is characterized ~n
that the pressure mechanism~ comprise at lea~t one
rod-like element arranged o~er at least paxt o* the
long~tudinal extension o~ said succe~sive con~eyor
floor3, ~aid rod-like ele~ent having a smooth lower
~urface ~acing the conveyor ~loors and mechanically
controlled support mean~ for the rod-like element
allo~ing said rod element to lie under co~trolled
. pres~ure against the strips to be joined entrained by
the conveyor ~loor~ alignment means arranb~ed betwee~
said rod-like element~ ~or aligning the strips to be
~oi~ed in a direction perpendicular to the longitudinal
extension of the conveyor ~loor~ an~ joi~ting material
applging means.
~ hese and other functlonal and constructional
~eature~ of the invention will be more apparent from
the detailed de#cription which follows relating to a
2~ pos~ible prefe~red embodiment of the invention, where-
in a single crowding conveyor floor i~ provided an~
.. th~ jointing material is a~ adhesive-coated thread,
the embodiment being shown in the accompanying
drawing~, in which:
3 Figure 1 i~ a diagrammatic plan view of the appa-
ratus according to the inventio~; and
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Figure 2 is a seotional v~ew o~ the apparatu~
t~en along the plane II-II o~ ~ig. 1.
~ Yith refere~ce to the cited drawing figures, there
are indicated at 1 th~ belt~ which form the feeding
conve~or floor, whereon an operator, located at the
machine input end~ dispo~e~ the strips to be joined
edgewise, such belts, being equipped with a belt
tensioner 2, are run betwee~ drive pulleys, such as
the one indicated at 3 i~ ~igure 2, which are ~eyed
rigidly to a shaft 4~ and pulleys, ~uch as the one
indicated at 5, also in ~igure 2, which. are idly
~ou~ted to the shaft 6.
The belt~ o~ the crowdi~g conveyor floor are
indicated at 7 and are run between drive pulleys which
are keyed r~gldly to the shaft 6-and pulleys which are
idly mounted to a shaft 8, neither being shown in
~iguxe 2~ since they remai~ hidden respectively behind
the pulley 5 and one o~ the splicing rollers which,
as explained hereinafter, is also mounted to the ~h~ft
8; the belt~ 7 are equipped with a belt tensioner 9.
Bars 10 and 11, being carried by the structuxe 12
- o~ the machine, form a supporting and abutment element,
re~pectively for the belts 1 and 7 of the feeding and
crowding conveyor ~loors.
The motio~ is derived, for either con~eyor floors,
~rom an electric motor 13; a ~procket chain 14
;. trans~er~ the motion to a sprocket wheel 15 which i~
keyed rigidly to the sha~t 4, a chain 16 transmitting
the motion, through a speed reducer, between the
sproc~ets 17 and 18; the latter is rigid with the
sprocket wheel 19, wherefrsm motion is derived through
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a chain 20 for the sprocket wheel 21, which is
keyed riæidly to the sha~t 6.
Overlyin~ each of the belts 1 of the feedi~g
conveyor floor and each of the belts 7 of the cro~dinæ
conveyor floor, are re3pective pressure elements which
are operative to pre3s or bias the wooden ~trip~
against said conveyor ~loors, ~uch as to cause the
same to mo~e under frictional en~agement. ~ach o~ the
pressure elements overlying the ~eeding conveyor ~loor
consist~ of a rod 22 kinem~tac~lly connected to a
statio~ary arm 22a, which e~tends ~rom a crossmember
23 o~ the machine frame, through ~ rocker arm 22b
pi~oted in 22k a~d on which the rod 22 is hinged in
22h by means o~ a lug 22i rigid therewith. ~he rod 22
i~ pushed towards the belt 1 by a pneumatic cylinder
22¢~ the pressure o~ which may be adjusted. ~rom the
rod 22, there extends a lug 22d which i~ slidably
guided by ~ork-liXe guides 22e, rigid with the arm
22a to preve~t lateral inclinations o~ rod 22. The
front end 22f of the rod 22, bent upwardly to provide
a ~laring inlet for the strips to be proce3~ed, i8
positioned æub3tantial1y at the wood strip ~ligning
mechanism~ which will be e~plained h~reina~ter, wherea3
the rear end 22~ protrudes with respect to the belt 19
to e~tend o~er a contiguous end portion of the belt 7.
The rod 22 has a ~mooth lower surface faci~g the strips
to be ~oined.
Quite similar to the above is the constructio~
of the pressure element~ or pushers overlyiDg the
belts of the cro~ding con~-eyor floor. One thereo~
~hown in ~ig. 2 i~ formed by a rod 24 kinema~ically
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supported by the stationary arm 24a, connect~d to the
crossme~ber 25 throu~h a rocker arm 24b,.and pu~hed
by pneumatic cylinder 2~c. From rod 24 a lug 24d ex-
tends W~li chis slidablyguidedby the ~ork-likeguides
24e. It will be understood that the kinematic
connection o~ the rod 24 is analoguous ~o that of
rod 22. The front end 24f o~ the rod 24 i~ positioned
substantially at the pulleys which are keyed to the
~haft 6, and the rear end 24~ is in a more forwardl~
loca~ed p~sition with respect to the jointing roller~
which will be de~cribed hereinafter.
The aligning mechanism ~or the strips to be
joined together edgewise comprises a shaft 26 with
~top pa~ls 26' rigid therewith and shoWn in the
drawing figures in a strip stopping position. ~he
. rotational movement of the mechanism is controlled by
~E se known strip contacting sensors 27 and 28,
which are adjustably supported by sliders 29 a~d 30
~lidably supported on the guidss 31 and 32, ~ollowing
consent by the sensors 33 and 34 which are removably
attached to a rod 35, in co~formity with the modes
explained hereina~ter, with re~erence to the machine
operation.
~he jointing materiæl applying means comprise
three mechanisms, indicated i~ ~ig. 1 at 36~37 and
38~ whereof the one indicated at 37 will be described
in detail with re~erence to ~ig. 2. Such a mechanism
consists o~ one of the roller~ 39 rigidly keyed to
the shæft 8, which i~ driven to rot&te by a variable
30 ~peed electric motor 40 through a chain 41, and a
rolier 42 which is suppo.rted idly on the arm 43,
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~ournaled and slidable on the shaft 44. The arm 43
carries~ moreover, a coil 45 o~ adhesiYe coated
thread 46, constituting the jointing material ~ se
known and ultrasonic welding dev~ce or sono-trode 47
effecting the melting of the adhesive by means of
~ ultrasolmds emitted by a generator included in the
machine. At the end o~ the ~rm 43, there is provided
a pneumatic cylinder 48 carried by a shaft 49, which
performs the dual function of allowi~g the arm to be
rai~ed~ and accordingly separation of the roller 42
from the sheet for carryin~ out ad~ustment operations,
and of pressing the roller 42 again~t the sheet or strip
with a force the amount of which is con~idered to be
most ~uitable for proper operation.
15~or applyi~g the jointing material 46 to th~
. lower fac0 of the wood strip~, a coil 50 of adhesi~e
material coated thread i~ provided which is carried
b~ the arm 51 rigid with the slee~e 52, slidably
mounted on the crossmember 53 of the machins structure;
the sono-trode 54 being also connected to said arm 51.
~ explained hereinabove, the deqcribed joi~ti~g
material applying mechanisms are slidable transversely
to the machine~ by virtue of the sleeve 52 and cross
member 53~ thereby they can be carried at any point
of the roller~ 39 for applying the jointing material
to the most suitable looation.
~ inally, there is indicated at 55 a ~ se known
sensor adapted to detect the pas~ing by of the wood
strips~ and controlling a microswitch not shown
provided on the supply side o~ the electric motor 40;
&aid sensor 55 being supported by a slider 56 slidable
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on the guide 32.
~he appar~tus operates as follows.
Onl~ when ~e fir~ ~trip laid by the operator
onto the belts ~ o~ the feeding conveyor floor
contact~ both se~sors 33 and 34, the strip is suffi-
ciently aligned i.e. perpendicular to the longitudinal
feeding direction o~ the apparatus a~d only then
a conse~t i~ emitted by them for the raising rotation
of the stop pawls 26' of the aligner 26~ following
a short time interval which is controiled by a timer
operati~e to permit the strip to rea~h contact with said
stop pawls 26'. Re~erse sinking rotatiGn of the stop
pawls 26~, to block the passing of the ~ollowing
#trip which has to be aligned, occurs a~ the trail~ng
edge of the ju~t considered strip pa~se~ under the
sensor 27.
It will be appreciated that the raising and
si~king rotatio~ of the stop pawls 26' is obtained by
the action of a pneumatic cylinder (not sho~n), which
acts on the ~haft 26 through a crank mechanism
causing rotation through about 90 of this shaft irA
one or the other direction. The cyli~der is actuated
through a ~E se known controlling electric circuit
controlled b~ the above described ~ensors 33,34 a~d 27.
It will be understood that, when the ~trip to be
entrained by the feeding con~eyor floor is not aligned~
i.e. is not perfectly perpendlcular, one of the senso~s
33 or 34 i8 not actuated and no consent is given for
the raising rotation of the stop pawls 26'.
3 Consequertly the strip is further entrained by the
feeding conveyor floor until it reaches one of the
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~top pawl~ 26' with one point thereof which i~
prevented from moving further and slides with respect
to the conveyor floor while the other portion oi the
strip is ~urther entrained until alignment with the
perpendicular direction occurs and also the other of
the sensors 33 or 34 is actuated, giving thereby
consent ~or the rai 9ing rotation of the stop pawls 26'
after the described short time interval allowing
the relevant strip portion to travel the ~hort
distance between the sensors 33 or 34 and the stop
pawl~ 26~, such distance being normally shor~er than
the width of the processed strip. 0~ continuing it~
advance movement and with the stop pawls 26' in
blocking positio~ the considered strip gets i~to
contact with the sensor 28 which-releases the rai~ng
rotation of the stop pawls 26' ~uch as to allow the
following strip to pass past it only i~ consent is
gi~en by the se~sor~ 33 and 34, i.e. only if the
following strip is in contact with both sen~ors 33
and 34, i.e. is ali~ned. An automatic control cycle
of ~he aligner is thus established.
As the strips are transferred from the ~oading
con~eyor floor to the crowding conveyor floor, owing
to the ~ower speed of the lattsr with respect to the
former, the strips tend to crowd i.e. to approach
each other. It will be apparent that the prsssure
elements 22,24 pressi~g the wood strips against the
belts of the con~eyor floors ensure agai~st the risk
of exce~sive slipping of the same with respect to the
3 belt3, and a~-oid overlapping of two con ecutive strips
or cli~bing o~ one ~trip above the other.
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In ~act, it will be appreciated that the pre~sing
action of the pre~ing rods 22,2~ which are
- preferably made of steel should not sxceed a cer~ain
degree,si~ce in the crowding con~eyor floor a
slipping o~ the proces~ed strips wlth respect to the
con~eyor belts of thè conveyor ~loors should be
allo~ved, as hereinPfter described. On the other hand
the pressing action should not be excessively low,
since otherwise in the feeding conveyor an uneven
slipping o~ the ~trips wilh re~pect to the conveyor
belts may occur and an inclination thereof with respect
to the alignment direction may happen after the align-
ment deYice 26, 26'
Moreover in the crowding conveyor floor the
climbing of the strips one o~er the other ~hould be
prevented as above described. It will be appreciatedthat this controlled pressure de~ree of the pres~ing
rod~ 22~24 against the strips to be processed i~
obtained on the one hand by the weight itself of the
~0 pre~sing rods 22~24 and the roclcing support the~eof
and on the other hand by the controlled pressing
-action o~ the inclined pneumatic cylinders 22c and
24c. It will be under~tood that the point in which the
cylinders 22c and 24c act i~ selected in the area
where the danger of ~rregular slipping
or ¢limbing of the strips is greater. In fact, owing
.. to the oscillatable support o~ the pressing rods 22
and 24 on the respective rocker axms 22b and 24b the
pres~ing action is greater in the area of the point
of action of the piston rods of the cyli~ders 22c
and 24~. ~oweYer this localized greater pressinæ
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action i~ compen~ated by the horizont~l component of
the inclined piston forcet which create~ an anti-
cloc~qi~e movament o~ rotation about the pivot 22h,
22k and 24h, 24k as will appear clear to tnose ~kllled
in the art~
As the first strip while sliding get~ in contact
with sensor 55, the latter is raised and releases
the ~tarting of the motor ~0, which drives the
jointing materiRl applyin~ rollers 3~, which by
rotating with a lower peripheral speed t~an the
crowding conveyor floor, exert on the strip a braking
action, causing a slippage thereof with re~pect to the
¢o~Yeyor belt~ 7, and conseauently a deceleration
thereof such as t¢.produce contact with the oncomni~g
following strip~ to thu~ produce the continuous sheet
or ply which is join~ed.
Upon rotation o~ the roller 39, the adhesiYe-
coa~ed threads 46 are progressively pressed on the
one side by the driving roller~ 39 and on the other
side by ~he.idle rollers 42 against the advancing
jointed strips, which, ~hile advanci~g under the
- ¢ontrolli~g action o~ the rollers 39 cause rotation
o~ the idle rollers 42, thereby to exert a pulling
a¢tio~ on the adhesive-coated threads which are thu~
25 unwound ~rom their coils 4~ and 50 and caused to pas~
through the heating device~ 47 and 54 thereby to cause
t~e adhesive coating of the thread to attain a melted
condition be~`ore being ~pplied to the strips by the
pressing action thereon o~ the rollers 39 and 42~
3 It will be understood that the heating devices 47 and
54 may be of con~entional electric resistance type.
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Under normal conditions, the motor 40 is kept
movi~g constantly on account of the achie~ed
continuity o~ the sheet or ply u~1der the sensor ~5.
However, i~ for a reason whatever, the strip suppiy i8
momentarily discontinued, and a gap is formed under
the sensor 55, then the sensor 55 is lowered and the
motor 40 stops to cause the jointing material applying
rollers 39 to stop thereby stopping in turn the
contacti~g sheet or ply. Si~ce said rollers 39 will
only resume their moYement upon arrival o~ a ~resh
~trip, it will be apparent how no discontinuity is
created in the jointed sheet or ply.
It is to be noted that ~he output speed o~ the
joi~ted ply~ and accordingly the machine own output,
~s proportional to the ~peed of the joint material
applying rollers 39, which as me~tioned above al~o
perform the ~unction of friotional rollers.
In ~act, as Yisible in ~ig. 1 rollers 39 are
large enough to per~orm such double function, taking
into account that t~e adhesiYe threads are sufficiently
thin for the purpose.
~ i~ally~ provision i~ made in the controlling
¢ircuitry for cancelling the automatic cycle de~cribed
aboYe, when it i8 desired to remove an undesired
strip processed by the machine.
The machine de~cribed hereinabove ~ill obviously
include means for supplying the strips to this
apparatu~, a cutter for reducing the resulting
continuous ply to size, and discharging and quic~
3 pili~g means.
The inYention as described hereinabo-ve is
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suscep-tible to many mod-i~ications and variations~
all o~ which fall within the scope of this inventive
concept: for example, the adhesive provided on the
splicing ~hxead could be melted by mean~ o~ the heat
genexated by a spirally wound, and possibly encased,
electrical re~istor, throug~l the inside whereof the
thread is pa~sed in the presence of a co~pre~sed air
jet .
