Note: Descriptions are shown in the official language in which they were submitted.
~043690
A STACKING AND TRANSFERRING DEVICE FOR
CELLOWRAPPERS FOR CIGARETTE PACKS :- -
This invention relates to machines for pack-
ing articles, in particular, cigarette packing machines.
More specifically, the invention relates to cello-
wrappers which rewrap packs of cigarettes in a
cellophane sheet or other similar material.
These machines, to automatically cellowrap
cigarette packs or other similar packs at a uniform rate,
commonly use a so-called star wheel consisting of a
certain number of radial pockets which are angularly
equidistant from each other. This wheel is jog-operated
by an intermittent motion mechanism. During the dwell
between each ~og, the mouth of one of the radial
pockets stops in alignment with the outlet of a coupling
station to receive a cigarette pack together with a
cellophane sheet which is engaged by the pack during
transfer from the station outlet to the mouth of the ~
pocket. The appropriate folding of the cellophane sheet ;
round the pack will be completed in successive rotary
; steps of the star wheel. The packs to be cellowrapped
must be fed in an orderly manner to the coupling
station where each pack is engaged by transferring
means, which lead it to the insertion into the relative
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star wheel pocket, after being orderly coupled to a :
cellophane sheet, located in position on the transfer
path from the station to the pocket aligned with it.
The problem of the pack feed to the coupling
station, and the one, concomitantly correlated with it,
of the transfer of the pack, coupled to a relative
sheet, in the mouth of the pocket which is stationary
at the station outlet, is, generally speaking, solved,
in the following two manners:
D a) By means of an endless conveyor, of the
chain type with pushing paddles or cross-
bars, aligned with the stationary pocket
and located unter a feed hopper, from
which the stacked packs are successively
taken by the conveyor crossbars.
b) By means of a feed belt, which delivers ~ .
on a plunger head each successive
leading pack of the row of packs conveyed
by the belt itself. This plunger
. constitutes a first transferring means,
which sequentially lifts each row leading
pack, in order to form from the bottom a
stack of packs of which the top one is
sequentially transferred into the
~: corresponding pocket of the star wheel,
by a second plunger transferring means : : .
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which is operatively aligned with the
pocket and whose motion is in phase
opposition in relation to the motion
of the first plunger transferring means.
Both the above systems are inadequate when
the speed or production rate of the cigarette packing
machine exceeds certain values, considered so far as
barrier values. For instance, in the first system as
above, the descent by gravity of the packs from the
feed hopper on the underlying chain conveyor gives
rise to catching and transferring irregularities,
when the cellowrapper operating rate exceeds a certain
maximum safety value. In the second system, as above,
there exist, under the same conditions, limitations to
the rate itself due to the existence of idle times
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between the linked phases of transfer, and to the fact
that the motions of the two plunger transferring means
cannot obviously exceed the limit of the interference or
crossing of the respective strokes. In fact, the
lifting plunger cannot lift a pack if the overlying
transferring means has not completed its return stroke
after the insertion of a previous pack into the mouth
of the pocket aligned at a given moment with it.
Furthermore, the feeding belt cannot feed a new pack
if the lifting plunger has not first completed its
return or descent stroke. Finally, the cellophane
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sheet which must be coupled to a pack coming out of the
coupling station obviously cannot be fed in posit~on
transverse to the pack in~ertion path if the trans- -
ferring plunger has not first completed its return ;~stroke, a condition which, as previously pointed out,
conditions also the lifting of the pack to the top of
the stack.
These conditions of the correlated inter-
calation of the motions of the lifting plunger and of
the transferring plunger involve, in the respective
alternate rectilinear motions, peaks of acceleration `~
ant relative forces of inertia, which, when the
production rate exceeds certain limit values, are
decidedly incompatible with the delicate nature of the
packs to be cellowrapped~ in the case in point, the
cigarette packs.
An ob3ect of this invention is to increase
beyond predetermined limits the~production rate of a
cellowrapping machine comprising a lifting plunger
and a transferring plunger without exceeding the
safety limits in the accelerations and in the forces
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of inertia, but by reducing the idle times of the in- -
; tercalatet operations ant thereby increasing th,e
number of operating cycles of the cellowrapping
machine~per unit o~ time.
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Su tantially, according to this invention,
this purpose is achieved with a characteristic
stacking-transferring device for cellowrapping machine,
comprising stacking or lifting means and transferring
or inserting means, in which the stacking means and the
transferring means are susceptible of alternate motions
intercalated between each other and are both provided
with pack engaging means, capable of operatively inter-
fering with the feed path of the packs arriving at the
basis of the stacker, respectively with the path of
the pack transfer from the top of the stack into the
stacker, only in the respective active travels, while
they are driven to accomplish the correlative return
travels in conditions of substantial non-interference
with the paths themselves, so that the lifting of a
pack in the stack can be started by the stacking means,
before the associated transferring means have completed
their return travel, relating to the transfer of the
previous pack, thus obtaining an increase of the
cellowrapper rate of production, without exceeding
critical values of acceleration in the alternating
components of the device itself.
According to a further broad aspect of the
present invention, there is provided a transferring and
stacking device for a cigarette pack cellowrap machine
having conveying means for delivering packs one after
another to be cellowrapped and a step by step rotatably
driven star wheel with a plurality of radial pockets
receiving successive cigarette packs each with an asso-
ciated cellophane sheet. The device comprises means for
retaining a plurality of cigarette packs one above the
other in a stack. First and second transferring means
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are continuously reciprocated each in phase opposition
to the other and have a transverse component of dis-
placement during reciprocation causing each transferring
means to pass through the path of movement of the packs
during the forward operating strokes and to prevent in-
terference with the path of movement of the packs during
the return strokes. The first transferring means removes
cigarette packs one after another from the conveying means
and delivers each such pack to the bottom of the stack
held by the retaining means causing the uppermost pack of
the stack to rise. The second transferring means removes
the uppermost pack from the stack and delivers such packs
each with a sheet of cellophane to successive pockets of
the star wheel.
The foregoing and other objects and
advantages will appear more fully hereinafter from a
consideration of the detailed description which follows,
taken together with the accompanying drawing wherein
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one embodiment of the invention is illustrated by way
of exampleO It is to be expressly understood, however,
that the drawing is for illustration purposes only and is
not to be construed as defining the limits of the
inventionO
FIGURE 1 is a schematic side elevation of a
stacking-transferring device according to the present
invention, fitted to a cigarette pack cellowrapping
machineO
FIGURE 2 is a perspective view of the device
of FIGURE 1 with the stacker at the beginning of its
operating phase; and
FIGURE 3 is a perspective view similar to
FIGURE 2 with the stacker at the end of its stacking
phaseO
With reference to the drawings, in the
illustrated embodiment, pack feed means at the bottom
of the stacker is provided by the conveyor comprising
- the pair of endless belts 1 and 2, which sequentially
transfer packs (receîved, for instance, from a feed
hopper, not illustrated) to the stacker lifting means.
In the stacker, the sequential lifting of the
packs is accomplished by a pair of lifting mechanisms ~ .
3, each of which consists substantially of an
~rOta~
A articulated parallelo~ram system, composed of two~crank
discs 4 and 5 coupled to each other by means of
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connecting rod 6. This connecting rod carries a fork
element 7 which always remains parallel to itself in
its different positions of elevation since connecting
rod 6 is continuously driven by cranks 4 and 5 in a
motion of translation in closed circuit. Fork 7 extends
horizontal-ly:in front of the delivery end of belt 2, and
the vertical component of its total displacement i~
designed to have a value corresponding to twice the
thickness of cigarette pack P to be cellowrapped. The
horizontal component of the same displacement has such `~;~
a value as to bring the fork 7, in certain intervals of
its operating cycle, in conditions of non-interference
with the pack di~charged by belt 2 and, consequently,
al90 with the stack P2, P3 (Fig. 1 and 3) which moves up
in the area of thi 9 pack Pl.
Under operating conditions, at every worXing
travel of the two forks 7 which operate in timed
relationship, moving towards and away from each other,
symmetrically from opposite sides in relation to the
position of pack Pl, a stack of two packs P2, P3 is
formed of ~hich the bottom pack P2 is supported by
retaining means 8, which may comprise a spring retain-
ing slide block, which is already known. The transfer
of the top pack P3 of stack P2, P3 into pocket 109 of
the star wheel 9 is operated by a pair of transferring ~.
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mechanisms or devices 10, each of which is substantially
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an articulated parallelogram, consisting of two~crank
disks 11, 12 and of a connecting rod 13 articulated
to themO Each of the two connecting rods 13 has a
plunger 14, the two plungers 14 being staggered in
height between each other as to enable them to superim-
posed.
The joint motion of the two lifting mechanisms
3 occurs in phase opposition in relation to the joint
motion of the two transferring mechanisms 10. This
means that, when forks 7 are at the lower stroke end
the plungers 14 are at the outer stroke end, that is,
towards the mouth of pocket 109.
As it will be clearly understood from the
comparative examination of FIGURES 2 and 3, forks 7
can lift a pack without waiting for plungers 14 to
complete their return stroke~ This is possible because
the return stroke of plungers 14, similarly to that of :
forks 7, move outwardly away from one another or
occurs in conditions of non-interference with the ~:~
transfer path of pack P3 to pocket 109 whereby the
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upper.pack P3 of the stack ~P~, rJ) can be brought on
this path by means of lifting devices 3 without waiting
far pushers 14 to complete their return stroke since
they do not interere with this pack due to their
8pacing :or interdistance~ For the same reason, a
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cellophane sheet C can be fed in advance in the po~
A tion in which pack ~ will engage it, dragging it in
the transfer stroke to pocket 109.
Furthermore, because of the non-interference
with forks 7 during their return stroke, belts 1 and 2
can feed a new pack Pl without having to wait for the -
forks to complete their return stroke. In fact, pack
Pl passes under forks 7 which are reciprocally moved
away from each other in their descent motion till the
point where they do not interfere with the new fed pack.
Thus, according to the invention, the
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possibility of anticipating the presetting of a pack -
P3 in relation to the end of the return stroke of~
plungers I4 which have operatet the transfer of the
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previous~pack, and the correlative, intercalated
a~nticipated~feed o~f a new pack Pl,~ 1D relation-to the
~; return~stroke of~forks 7, after the lifting of the
previou~pack~P3, allow;a considerable increase iD the
cell ~ pper ru ming~rate, because~of the substantial
20~ reduct~ion~of the~ma~hine idle times, a~ preannounced
in~thé~introductive~part of this specification. It is
how:ever~ evid ~ ~that~this~increase involves accele-
ration~peaks,~in the reciprocating~ tLon ~parts oP the
device,~much~lower th~Ln~those~;which~would be
exFeriencéd,~ith~the~same~increase,~in a~traditional
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stacking-transferring device, which does not use the
said idle times for the anticipated pack feed. This is
the point from which there derives one of the main
advantages of the proposed device.
Although but a single embodiment of the ~ -
invention has been illustrated and described in detail, -
it is to be expressly understood that the invention is
not limited thereto. Various changes may also be made
in the design and arrangement of the parts without
departing from the spirit and scope of the invention
as the same will now be understood by those skilled in
the artO
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