[0001] The invention refers to a device to be fitted to automatic presses for packing tobacco
parcels, which substantially permits, by means of a permanent pressure effect on the
heap about to be formed in the charging boxing, to employ considerably lower boxing
than the ones required at present: in this way, a consistent reductions of the plants
are reached and a better adaptability to the contingent requiments. The tobacco, either
in the free leaf state or in the one of the foil separated from the rib, for commercial
and technological reasonsis brought on the mar ket in wood or paperboard containers-having
a capacity from 200 to 500 Kgs.
[0002] For filling the tobacco into. the containers and compressing it at approx. 250-350
Kgs./Cubic meter, loading devices are at present used which perform tamping by means
of oildynamic presses operating in charging boxings positioned on the containers.
The descending press plug then tamps the tobacco in the containers; however, since
the tobacco in free state is highly bulky, these plants require considerably hight
boxings. This, in general, makes the plant setting-up in buil dings problematic.
[0003] The invention permits the problem solution by means of an auxiliary device, which
contemporary phase with the tobacco loading, submits the heap which is being formed
in the boxing, with alternate motion to a permanent pressure effect. The said device
can be fitted integral on the boxing outside and, on the fixed setting-up part, a
motor reducer with self-braking motor is employed driving a horizontal shaft: this
one acts as the articolation of the lever system bearing the tamping device. On the
said shaft, a pair of pinions is fitted which drive an arm pair bearing a tamping
fork in synchronism and with an alternating motion. With an alternating motion too
from outside, through a slit, the fork penetrates with a razing motion into the boxing
and compresses the heap which in the meantime has been formed; the fork is then lifted
and gets out again. In this way, the fork does not interfere on the descending tabocco
of the charging phase.
[0004] The proceeding foresees the tobacco arrival on ribbon 1 which dischar ges on the
reversible ribbon 2 driven by the motorreducer 3. From this ribbon, by means of the
rotating distributor 4, which guarantees uniform distribution and stratification,
the tobacco falls into the hopper 5 which fits it into boxing 6. The distributor rotating
device 4 is fitted with motorreducer 7 which lets it rotate by means of belt 8. The
boxing is in steel plate and is properly reinforced to withstand the side pressures
made by the tobacco during the pressure phase. The boxing is mounted on a special
truck 9 foreseen for this purpose travelling on trail 10 by means of motorreducer
11 with pinion-chain Iran smission on the wheel axle 12 to enable its transfer from
the loading zone above scale 13 to the pressing zone 14. The consentnent to the truck
movement is determined by the proximity contact fitted on scale 13. The operation
principle of the tamping device is as follows: on structure 15 integral with boxing
6, a motorreducer 16 is mounted with a self-braking motor, which by means of pinion
17 and chain 18, drives shaft 19 on which pinions 20 and 21 are keyed. Through chains
22 and 23 fitted on the free running pinions 24 and 25, the said pinions 20 and 21
drive the couple of arms 26 and 27 bearing fork 30 on articolation joints 28 and 29.
The fork has at first a sinking movement in order to perform a pressing effect, but
then it is lifted to get out of the boxing. This allows a continuous flux of the descending
tobacco. The chains 22 and 23 are connected to arms 26 and 27 by means of arti culated
pins 31 and 32 and, in this way, the chains when rotating let the arms 26 and 27 and
consequently the fork 30 horizontally move on the top and bottom dead points which
permits the connection and disconnection of the forks inside the boxing in the corresponding
slit system 33. While the transmission system of chains and pinions is fixed on the
bearing structure 15, the arms 26 and 27 jointly to fork 30 are anchored on a roller
shutter 34 which, therefore, moves alternatively in vertical sense along the whole
travel between the top . and bottom dead points of the pinions 20, 21, 24 and 25.
On scale 13 three proximity contacts are fitted which give the consentments to the
sequence transition of the whole system consisting of the truck and boxing 6. The
first proximity contact lets the motorreducer 16 start which controls the movement
of the tamping device. This occurs when in the boxing already 50 to 100 Kgs. of tobacco
are heaped, which corresponds to a height of an adjustable boxing of 1.50 m. The second
proximity contact stops the whole system when the heap weight is appro ximately 5
- 10 Kgs. less the final weight fixed in advance. This stop avoids oscillations to
the scale 13 which would cause troubles to the weighing system; these oscillations
are generally caused by the movements of the tamping system.
[0005] Therefore the final phase of the loading operation is performed when the boxing is
at a standstill. The stop through the second proximity contact occurs but when the
fork 30 out of the boxing 6. With a view to avoiding that the pressing plug, when
sinking, meets the fork inser ted inside the boxing, the third proximity contact is
regulated accor ding to the net final weight fixed in advance. Its intervention causes
the inversion of the reversible ribbon 2 towards the other boxing and, at the sime
time, starts the truck 9 to transfer the filled boxing in the pressing zone 14.
[0006] A not limiting execution form is illustrated by the drawings of Tables 1 and 2. Fig.
1 represents a boxing under the press during the pressing phase, while the other boxing
is in loading phase. Fig. 2 is a scheme of the operation principle of the tamping
device. Fig. 3 is a front view of the transmission chains controllong the movement
of the fork arms. Fig. 4 is a view of the fork when passing through the slit.
[0007] The above mechanical system for the fork drive can be replaced with an oildynamic
or pneumatic system controlled by special electric valves foreseen for this purpose,
the consentment of which is given by the proximity contacts already mentioned of the
scales.
1) Tamping device to fit to an automatic pressing machine for tobacco parcel packaging,
characterized by the fact that permits by means of an Auxiliary device which, with
contemporary phase with the tobacco loading, submits the head which is being formed
in the boxing, with alternate motion to a permanent pressure effect. The said device
can be fitted integral on the boxing outside and, on the fixed settin-up part, a motor
reducer with self-braking motor is employed driving a horizontal shaft: this one acts
as the articolation of the level sy stem bearing the tamping device. On the said shaft,
a pair of pinions is fitted which drive an arm pair bearing a tamping fork in synchronism
and with an alternating motion. With an alternating motion too from outside, through
a slit, the fork penetrates with a razing motion into the boxing and compresses the
heap which in the meantime has been formed; the fork is then lifted and gets out again.
In this way, the fork does not interfere on the descending tobacco of the charging
phase.
2) Tamping device to fit to an automatic pressing machine for tobacco parcel packaging,
according to the previous claim, characterized by the fact that on structure 15 integral
with boxing 6, a motorreducer 16 is mounted with a self-braking motor which, by means
of pinion 17 and chain 18, drives shaft 19 on which pinions 20 and 21 are keyed. Through
chains 22 and 23 fitted on the free running pinions 24 and 25, the said pinions 20
and 21 drive the couple of arms 26 and 27 bearing fork 30 on articulation joints 28
and 29. The fork has at first a sin king movement in order to perform a pressing effect,
but then it it lifted to get out of the boxing.
3) Tamping device to fit to an automatic pressing machine for tobacco parcel packaging,
according to the previous claims, characterized by the fact that the chains 22 and
23 are connected to arms 26 and 27 by means of articulated pins 31 and 32 and, in
this way, the chains when rotating let the arms 26 and 27 and consequently the fork
30 horizontally move on the top and bottom dead points which permits the connection
and disconnection of the forks inside the boxinf in the corresponding slit system
33. While the transmissions system of chains and pinions is fixed on the bearing structure
15, the arms 26 and 27 jpin tly to fork 30 are anchored on a roller shutter 34 which,
therefore, movers alternatively in vertical sense along the whole travel between the
top and bottom dead points of the pinions 20, 21, 24 and 25.
4) Tamping device to fit to an automatic pressing machine for tobacco parcel packaging,
according to the previous claims, characterized by fact that the first proximity contact
lets the motorreducer 16 start which controls the movement of the tamping device.
This occurs when in the boxing already 50 to 100 Kgs. of tobacco are heaped, which
cOr responds to a height of an adjustable boxing of 1.50 m.
5) Tamping device to fit an automatic pressing machine for tobacco parcel packing,
according to the previous claims, characterized by the fact that the second proximity
contact stops the whole system when the heap weight is approximately 5 - 10 Kgs. less
the final weight fixed in advance. This stop avoids oscillations to the scale 13 which
would cause troubles to the weighing system; these oscillations are generally caused
by the movements of the tamping system. Therefore the final phase of the loading operation
is performed when the boxing is at a standstill. The stop through the second proximity
contact occurs but when the fork 30 out of the boxing 6.
6) Tamping device to fit to an automatic pressing machine for tobacco parcel packaging,
according to the previous claims, characterized by the fact that with a view to avoiding
that the pressing plug 35, when sinking, meets the fork inserted inside the boxing,
the third proximi ty contact is regulated according to the net final weight fixed
in advance. Its intervention causes the inversion of the reversible ribbon 2 towards
the other boxing and, at the same time, starts the truck 9 ti transfer the filled
boxing in the pressing zone 14.
