Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This invention relates to a conveyor for feeding sheet
material to a user machine.
More particularly, the present invention relates to
a continuous belt conveyor for feeding preshaped or punched
pieces of cardboard or the like from a feed and accumulation
apparatus for said preshaped or punched pieces to an intermitt-
ent machine for packaging cigarettes into hinged lid packets.
In the aforesaid feed and accumulation apparatus,
the preshaped pieces for feeding to said packaging machines
are generally stacked inside a column vessel down which they
descend by gravity, and from the lower end of which they are
- individually withdrawn by extractor means and deposited on an
inlet conveyor of a packaging machine.
A particularly effective example of such an apparatus
is described in Italian patent No. 922,092 of the same applicant.
In this apparatus, the preshaped pieces are continuously fed
~` into a vertical accumulation vessel and are extracted one by
one from the bottom thereof by suckers, which deposit them in
8uccession on a conveyor which feeds them in the same order to
an intermittent packaging machine.
Conveying the shaped pieces by a conveyor from an
accumulation vessel such as that heretofore described to an
intermittent packaging machine presents no substantial problem
when the operating frequency of the machine is relatively low.
However, considerable problems arise when a conveyor
is required to feed the preshaped pieces to a packaging machine
of very high operating frequency, for example an intermittent
packaging machine with an operating frequency of seven steps
per second or more.
In general, the technical specification which such
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a conveyor has to satisfy is extremely severe, in that it
must not only feed the preshaped pieces stepwise at a feed
frequency equal to the operating frequency of the packaging
machine to be fed, but must also ensure that the preshaped
pieces are positioned extremely precisely both longitudinally
and transversely at the end of each step, as these latter are
- generally subjected during their travel both to pre-folding
operations and to changes in direction. The terms "longitudinal"
and "transverse" are used herein to indicate a direction parallel
0 and a direction perpendicular respectively to the direction
in which the preshaped pieces are fed along the conveyor.
Presently known conveyors for feeding intermittent
packaging machines haveproved incapable of satisfying the
aforesaid requirements. These known conveyors are generally
, constituted by a continuous belt the upper branch of which
slides in contact with a flat support plate, and from the
outer surface of which project transverse projections defining
conveying compartments for the preshaped pieces. In the
aforesaid known conveyors, the width of the continuous belt is
substantially equal to the transverse dimensions of the preshaped
pieces conveyed.
Because of the width of the belt and the corresponding
weight of the moving parts, these conveyors are unsuitable
for feeding intermittent packaging machines at very high
operating frequency because of the inertia forces generated
during their stepwise movement, and which result in belt
vibration and an unacceptable imprecision in the position of
the preshaped pieces at the end of each step.
Furthermore, in the said known conveyors the belt
surface in contact with the preshaped pieces is generally rough
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and does not allow precise transverse positioning of the
preshaped pieces by the guide elements disposed along the belt
and arranged to cooperate with the transverse ends of~shaped
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pieces. ~:
. The object of the present invention is to provide a
conveyor which, in contrast to known conveyors, may be used for :~
feeding preshaped pieces to an intermittent packaging machine
. and in particular a machine for packaging cigarettes into hinged :
.: lid packets operating at very high speed.
The said obiect is attained by a continuous belt .:
conveyor for feeding portions of sheet material, particularly - .
., preshaped or punched pieces of cardboard or the like, to a
user machine, particularly to a machine for packaging cigarettes
into hinged lid packets, in which said belt is configured so
as to define conveying compartments for said preshaped pieces
and is arranged for use in combination with a vertical vessel,
. from the base of which said preshaped pieces are arranged to be ~ .
withdrawn individually, each to be deposited in a respective
conveying compartment and to be fed in.rhythmic succession to .
said user machine, wherein said belt is formed from at least
two continuous toothed belts each would endlessly around gear
wheels at least one of which is a drive wheel; a beam comprising
an upper
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flat surface extending between each pair of adjacent toothed
belts so that said flat surface projects above said belts; tie
bars extending above said beam to connect said belt together and
define said conveying compartments and slide shoes extending
laterally from each belt and engage slidably in a groove pro-
vided along the lateral surface of said beam to support the
respective belt relative to said beam in such a position that ~ -
the belt is disposed at a level lower than that of the upper
surface of said beam, said tie bars being disposed above said
beam at a certain distance therefrom.
The present invention will be further illustrated by
way of the accompanying drawings in which:
Figure 1 is a three-quarter perspective view from above
of a conveyor constructed in accordance with one embodiment of
the present invention;
Figure 2 is a plan view to an enlarged scale of a detail
; of Figure l; and
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Figure 3 is a section on the line II~-III of Figure 2.
Figure 1 shows a conveyor 1 for preshaped packaging
pieces 2 indicated in the figure by dashed and dotted lines. The
conveyor 1 is supported in a substantially horizontal position by
a base 3 which extends between an inlet station 4 and an outlet
station 5 at which the preshaped pieces 2 are transferred to a
second conveyor 6 connected to an intermittent machine (not shown)
for packaging cigarettes into hinged lid packets. A folding sta-
tion 7 is disposed in the path of the conveyor 1, and folds a
flap constituting one of the ends of the preshaped pieces 2. The
conveyor 1 comprises a longitudinal support and guide member 8
disposed in a substantially horizontal position above the base 3,
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and supporting, by its two ends, two shafts 9 and 10 disposed
horizontally and transversely to the axis o~ the longitudinal
.- member 8.
By way of bearings 11, two gear wheels 12 are rotat-
ably mounted on the two ends of the shaft 9 and each supports
and engages, together with a corresponding gear wheel 13 keyed :
. on the shaft 10, with a respective endless toothed belt 14
extending parallel to the axis of the longitudinal member 8.
~ne end of the shaft 10 extends rotatably through a sleeve 15 :
rigid with the base 3, and comprises keyed thereon a gear
wheel 16 which engages with a gear wheel 17 rigid and coaxial
with a Maltese cross 18 mounted rotatably on a shaft 19 carried
by the base 3. The Maltese cross 18 is engaged by the idle
rollers 20 carried by the device of known type 21 rigid with a
.. drive shaft 22 for driving stepwise the shaft 10, the relative .
gear wheels 13 and the belts 14.
As shown in Figures 2 and 3, bars 23 are mounted
transversely on the longitudinal member 8 and are substantially
of U cross-section, comprising two lateral flanges 24 extending
:;1 20 upwards from a substantially horizontal web 25 and provided with
a central longitudinal rib 26. Together with the flanges 24,
this latter defines two longitudinal grooves 27 disposed
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symmetrically about the longitudinal axis of the member 8, and
along which the upper branches of the belts 14 extend.
To the top of the flanges 24 there are connected, by
; screws 28 and 29 respectively, two flat plates 30 and 31 extend~
ing along the longitudinal member 8 and projecting laterally
therefrom in opposite transverse directions. A longitudinal
beam 33 is connected to the top of the central rib 26 by screws
32, and upperly comprises a flat surface coplanar to the upper .
flat surfaces of the plates 30 and 31 to constitute with these
latter two surfaces a support surface for the preshaped pieces 2.
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Each of these latter is disposed inside a respective conveying
compartment defined by two tie bars 34 extending transversely
to the belts 14 and connected thereto.
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Each tie bar 34 is configured substantially as an
inverted U and comprises a web extending above the upper
surface of the beam 33 and two lateral flanges extending inside
. the grooves 39 and each connected to one of the belts 14 by
way of a guide shoe 35.
This connection is made by a pin 36 locked between -
the guide shoe 35 by the washer 37 and provided with threaded
ends on which nuts are mounted for tightening together the tie
bar 34, shoe 35 and belt 14.
~The shoe 35 comprises laterally a flat surface in
.` contact with a lateral flat surface of the beam 33, and a
substantially rectangular lateral appendix 38 engaged slidably
in a respective lateral longitudinal groove 39 in the beam 33.
:,The upper and lower surfaces of each appendix 38 are
disposed in contact with the upper and lower surfaces respective-
ly of the relative groove 39 so as to keep the respective tie
bar 34 at a determined distance above the upper surface of the
.beam 33. The transverse position of the belts 14 and relative
tie bars 34 is controlled both by the shoes 35 and by a lateral
appendix 40 extending from each tie bar 34 above the plate 31
and comprising an end tooth 41 extending into a longitudinal
groove 42 provided on the upper surface of the plate 31.
The transverse position of the preshaped pieces 2
in the relative conveying compartments is controlled on one
side by a guide rib or shoulder 43 connected to the upper
surface of the plate 30 by screws 44, and on the other side by
a guide rib or shoulder 45connected tb the uppersurfaceofthe
plate 31 by screws 46. Whereas the shoulder 43 extends longi-
tudinally along the entire plate 30, the shoulder 45 is at
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least partially intexrupted bo;~h at the inlet station 4 and
the folding station 7.
At the station 4, the shoulder 45 is replaced by a
control gate 47 rotatably mounted on a pin 48 carried by the
plate 41.
In order to prevent the preshaped pieces 2 separating
vertically from the plates 30 and 31 and from the beam 33, ~
brackets 49 are connected to the shoulder 45and projectabove -
the plate 31 to support a vertical guide knife 50 extending
along the space lying between the stations 4 and 7. --.
At the inlet station 4 there is provided a device
which comprises a horizontal shaft 51 arranged to retain the
preshaped pieces 2 on the said support surface defined by the
plates 30 and 31 and by the beam 33 before their insertion .
below the guide knife 50, the preshaped pieces 2 having been
extracted in succession from the bottom of a vessel (not shown)
described in said Italian patent No. 992,092 and disposed
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vertically above the station 4. :~
The preshaped pieces 2 are extracted from said vessel
by an extractor unit (for the description of which reference :~ .
; should be made to Italian patent No. 992,092) comprising
three suckers 52, visible in Figure 1, connected to a suction
unit 53 and mobile upwards through holes 54 provided respective-
ly through the plates 30 and 31 and the beam 33. In order to
allow the suckers 52 to rise before an empty conveying compart-
ment is positioned below said vessel, each tie bar 34 laterally -
comprises a semi-circular notch 55 arranged to allow the passage ,~
of the central sucker 52.
In use, the belts 14 and relative tie bars 34 are fed
stepwise at a feed frequency determined by the drive unit ~:~
comprising the drive shaft 22 and Maltese cross 18.
The depositing of a new preshaped piece 2 on the.:
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conveyor 1 is carried out by the suckers 52, which rise upwards
- as soon as the periphery of the notch 55 in the fronttie bar 34
of said empty conveying compartment coincides with the periphery
of the central hole 54. On adhering to the preshaped piece 2
lying at the bottom of said vessel, the suckers 52 move
downwards and deposit this preshaped piece 2 on the conveyor 1
as soon as said empty conveying compartment is halted at the
end of the feed step in a central position relative to the holes
54, i.e. in the position shown in Figure 2.
The structural characteristics of the conveyor 1 enable
it not only to feed stepwise with a very high frequency (up to
seven steps per second or more), but also allow the preshaped
pieces 2 to be positioned extremely precisely both in the
longitudinal and transverse directions at the end of each step.
In this respect, in the conveyor 1 the inertia of
the moving parts is much less than that of known conveyors used
up to the present time for the same purpose, as the continuous
conveying belt of these latter has been replaced by the two
belts 14 of much smaller cross-section.
Furthermore, the belts 14 instead of sliding in contact
with a flat support surface are supported by the beam 33 via the
shoes 35, which reduce the friction forces acting on the mobile
elements of the conveyor 1 to a minimum. In this respect it
should be noted that the shoes 35 not only support the tie
bars 34 in such a manner that they never come into contact with
the beam 33, but also support the belts 14 inside the grooves
27 without them coming into contact with the tie bars 23.
This latter structural characteristic makes it
possible to use toothed belts 14. In this respect it is important
to note that in known conveyors, the lower surface of the conveyor
belt has to slide in contact with a support surface and is
therefore generally free from teeth in order to reduce friction
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to a minimum and guarantee a certain stability to the support
surface for the preshaped pieces.
Thus, the relatively low weight of the moving parts,
; the relatively small frict~on forces acting upon these moving
parts, and the use of toothed belts give the described conveyor
1 a feed precision which is much greater than that of known
conveyors, and allows it to operate stepwise at the necessary
frequencies of forward movement for feeding modern intermittent
'f packaging machines.
With regard to the transverse positioning precision
of the preshaped pieces 2 during their feeding, this is ensured
.~ by the relatively low friction between the preshaped pieces
~ and their support surface. This latter is constituted not by
. the rough surface of a belt as in the case of known conveyors,
but by a preferably polished or lapped metal surface.
As is evident from Figure 3, the belts 14 are supported `
by the shoes 35 at a level always lower than the level of the
upper coplanar surfaces of the two plates 30 and 31 and of the
. beam 33 constituting the support surface for the preshaped pieces
2.
Consequently, these latter never come into contact ~- .
with the belts 14 and may be continuously positioned transversely
by guide elements constituted at least partly by the guide
' shoulders 43 and 45. ~.-.
Numerous modifications may be made to the described
conveyor 1 within the inventive idea without leaving the scope
of the present invention. For example, it would be possible to
use three or more parallel belts 14 by interposing between
each pair o$ adjacent belts a guide beam similar to the beam 33. :
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