Packaging apparatus for producing and feeding blanks to a packaging station

The efficient machine conveyance of inexpensive, very thin-walled packaging material, especially plastic foils, presents special problems because of the low degree of firmness of these foils. In the present apparatus, the front end of a sheet of such material and blanks severed from it are transported continuously by suction air conveying members. These consist of a suction drum and perforated belts directly adjoining the drum, with no interruption occurring in the retention of the packaging material.

BACKGROUND OF THE INVENTION 
The invention relates to a packaging apparatus for producing blanks by 
severing them from a sheet of material and for feeding them to a packaging 
station by means of a blank-conveyor which consists of revolving laterally 
perforated belts with a conveying side for the blanks which is under a 
vacuum as a result of suction chambers arranged on the rear face. 
For the processing of packaging materials with "critical" properties in 
packaging technology, special measures are necessary to fix sufficiently 
the foils or blanks made from them during conveyance. At the same time it 
is important to guarantee uninterrupted retention both of the continuous 
sheet of material and of the blanks severed from it, until they are 
wrapped round the article to be packaged. 
A first solution to this problem can be found in German Pat. No. 1,169,361 
issued on Apr. 30, 1964. In this proposal the sheet of material is fed to 
a suction roller, on the outer shell surface of which suction bores open. 
The blanks are severed from the sheet of material on this suction roller 
by a revolving severing knife. The individual blanks are then transferred 
from the suction roller to lateral suction discs on the same axis, which 
likewise fix the blank laterally by means of suction bores. The article 
(pack) can be moved through between these suction discs in a radial 
direction, specifically carrying with it the blank which is pulled off 
from the suction discs as a result of slipping. 
The use of suction discs as a retaining and conveying member for the blanks 
has proved unfavourable because they are expensive to produce and are tied 
to specific maximum dimensons. In addition, when the blank (of 
appropriately large dimensions) loops substantially round the suction 
discs, it becomes more difficult for the conveyed pack to pull it off from 
the suction discs. 
Consequently, more recent solutions (U.S. Pat. No. 4,151,699 and German 
Offenlegungsschrift No. 2,949,685 of Dec. 11, 1979) work with laterally 
perforated belts, the conveying side of which is likewise exposed via 
suction chambers fixed in place to a vacuum which retains the blank and 
carries it along. A vertical plane conveying path for the blanks is 
possible by means of the perforated belts. This path can have sufficient 
length for separating the necessary conveying and packaging members from 
one another. Also, it is easier to pull a blank off from the vertical 
perforated belts by means of a pack conveyed transversely to it. 
However, in the known apparatuses with perforated belts of this type, the 
problem of severing the blanks from the sheet of material, whilst keeping 
them fixed continuously, has not yet been solved in the best possible way. 
SUMMARY OF THE INVENTION 
Consequently, the object on which the invention is based is to propose 
measures, by means of which, on the one hand, uninterrupted conveyance of 
the sheet of material and of the severed blanks until they are received by 
a pack or the like is guaranteed, with, at the same time, a simple and 
functionally reliable construction, and, on the other hand, a 
straightforward cut severing the blank completely from the sheet of 
material can be made. 
To achieve this object, the apparatus according to the invention is 
characterised in that located in front of the blank-conveyor is a suction 
drum known per se, in the region of which the blanks can be severed from 
the sheet of material and by means of which the blanks can be transferred 
directly to the perforated belts. In particular, the suction drum is 
located in the region of an (upper) deflecting roller for the perforated 
belts, in such a way that the peripheral surface of the suction drum or 
the blank conveyed thereon can be transferred directly to the peripheral 
surface of the deflecting roller of the perforated belts or to the belts 
themselves. At the same time, the invention ensures that the deflecting 
roller for the perforated belts is subjected to suction air at least in a 
peripheral region serving for transporting the blank. 
In the invention, therefore, two different conveying systems, namely a 
suction roller for making the severing cut when the blank is produced, on 
the one hand, and perforated belts for conveying the blank up to the 
packaging station, on the other hand, are placed in such a spatial 
relationship to one another that the blank severed on the suction drum can 
be transferred directly and without an intermediate conveyor to the 
suction belts appropriately closely adjacent thereto. The transition from 
conveyance of the blanks along a path in the form of a circular arc (over 
part of the periphery of the deflecting roller) to a plane conveying path 
(by means of the perforated belts) takes place in an especially favourable 
way in the invention since the perforated belts already run underneath the 
blank in the region of the deflecting roller. 
The suction air retaining the blank on the deflecting roller can be brought 
up to the blank in various ways. According to an advantageous embodiment, 
the deflecting roller is provided with (radial) suction bores which 
preferably correspond to suction holes in the perforated belts. In this 
case, the suction air is transferred to the blank through or via the 
perforated belts in the region of the deflecting roller also. 
According to an embodiment which is also advantageous, the suction chambers 
assigned to the perforated belts are prolonged into the region of the 
deflecting roller for the perforated belts, to form suction segments in 
the form of circular arcs. These extend in a peripheral groove of the 
deflecting roller in such a way that the outwardly open side of the 
suction segments can take hold of the blank (directly or via the 
perforated belts). 
Finally, it is possible to place the suction drum directly on the vertical 
conveying side of the perforated belts, in such a way that the severed 
blanks are transferred from the suction drum directly to the perforated 
belts conveying downwards.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The devices illustrated are parts of a packaging machine for producing 
cigarette packs 10 provided with an outer wrapping of an inexpensive 
plastic foil which presents packaging problems. For this purpose, a blank 
11 of packaging material is kept ready on a pack track 12 in a plane 
transverse to the direction of transport of the cigarette pack 10, in such 
a way that the blank 11 wraps itself in the form of a U round the 
cigarette pack 10 as a result of the relative movement. The cigarette pack 
provided with a blank 11 in this way is then conveyed into a folding 
turret 13 which makes the further necessary folds of the blank 11 in a 
known way. 
The blanks 11 are severed successively from a sheet of material 14 conveyed 
continuously (or intermittently). This sheet of material is conveyed by 
means of a pair of drawing rollers 15, 16 mounted above following 
conveying members. After the sheet of material 14 has been conveyed along 
approximately half the periphery of one drawing roller 16, it is 
transferred to an adjoining, parallel axis suction drum 17. 
On the suction drum 17, the blank 11 is severed from the following sheet of 
material 14. In the present embodiment, an approximately radially directed 
severing knife 18 is embedded in the suction drum 17 in such a way that 
its outer cutting edge projects beyond the shell surface of the suction 
drum 17. The severing cut is made by means of a revolving counter-knife 19 
at a predetermined and recurring cutting point, so that blanks of always 
the same length are severed. The above-mentioned severing device can also 
be designed in a different way. 
The revolving suction drum 17 is equipped with radial suction bores 20 
which open onto the shell surface of the suction drum 17 in several, 
preferably three suction rows 21 located at a distance from one another 
and which, when subjected appropriately to suction air, fix the sheet of 
material 14 or the blank 11. The suction bores 20 of the three suction 
rows 21 are each connected to common parallel axis suction channels 22 
which lead to an axial end of the suction drum 17 and communicate 
periodically with a suction groove 23 formed in a fixed distributor disc 
24 mounted next to the suction drum 17. The suction groove 23 extends over 
the entire approximately semi-circular conveying region of the sheet of 
material 14 or of the blank 11 on the suction drum 17. Advantageously, in 
the lower region, there is formed in the distributor disc 24 a vent bore 
25 (FIG. 9) which is separate from the suction groove 23 and which, as a 
result of venting the suction channels 22 and consequently the suction 
bores 20 in this region, makes it easier to transfer the blank 11 to a 
following blank-conveyor 26. 
By means of this blank-conveyor 26, the blank 11 is transported in a 
straight line, namely in a vertical plane. For this purpose, the 
blank-conveyor 26 consists of two perforated belts 27 and 28 arranged at a 
distance from one another. These are guided over upper and lower 
deflecting rollers 29 and 30. In the present case, the arrangement is such 
that the deflecting rollers 29 and 30 are disposed approximately at equal 
distances above and below the pack track 12. 
The perforated belts 27, 28 are subjected to suction air in the region of a 
conveying side 31, specifically either by means of individual elongate 
suction chambers 32 and 33 for each conveying side 31 or by means of a 
common suction box 34 (FIGS. 6, 7 and 8). The suction chambers 32, 33 are 
provided on the side facing the conveying side 31 with orifices or a 
continuous suction slit 35 which is covered by the conveying side 31 of 
the perforated belts 27, 28. In the region of the suction slit 35, the 
perforated belts 27, 28 are provided with suction holes 36 which enable 
the vacuum to be made effective by means of the suction chambers 32, 33 or 
the suction box 34 on the opposite face of the conveying side 31, so that 
the blank 11 is fixed during transport. 
As is evident especially from FIG. 4, in this embodiment the suction 
chambers 32 and 33 are formed in vertical supporting elements 37, between 
which a recess 38 is formed for pushing through the cigarette pack 10. 
During this pushing-through movement, the blank 11 is pulled off from the 
conveying sides 31 of the perforated belts 27,28 by the cigarette pack 10. 
The perforated belts 27, 28 run in trough-like depressions 39 in the 
suction chambers 32, 33 or the suction box 34. The narrow depressions 39 
are calculated so that the perforated belts 27, 28 running in them 
terminate approximately flush with the contact surface 40 facing the blank 
11. The suction holes 36 in the perforated belts 27, 28 and the suction 
slits 35 for the suction chambers 32, 33 are arranged offset inwards in 
relation to the longitudinal centre planes of these parts. 
The perforated belts 27, 28 are provided, on the inner face turned towards 
the deflecting rollers 29 and 30, with transversely directed rib-like 
elevations 41, as a result of which the perforated belts 27, 28 are 
designed as toothed belts. At least the upper deflecting roller 29 is 
equipped with corresponding depressions 42 into which the elevations 41 
engage positively. Because of this, an exact movement of the perforated 
belts 27, 28 which is slip-free in relation to the deflecting rollers 29, 
30 is guaranteed. The depressions 42 are formed in the region of turned-in 
portions 43 of the deflecting rollers 29, 30. These turned-in portions 43 
or flat grooves are designed so that the perforated belts 27, 28 fit in 
them and terminate essentially flush with the shell surface of at least 
the deflecting roller 29. A suction hole 36 is located between every two 
elevations 41. 
The present embodiments are designed so that from the take-over of the 
sheet of material 14 by the suction drum 17 up to the transfer of the 
blank 11 to the cigarette pack a continuous and uninterrupted fixing of 
the sheet of material 14 and of the blank 11 to the conveying members 
concerned by means of suction air is guranteed. The transfer of the blanks 
11 formed on the suction drum 17 to the blank-conveyor 26 is achieved in a 
special way. 
In the embodiment according to FIG. 1 and the following figures, the upper 
deflecting roller 29 of the blank-conveyor 26 is subjected to suction air 
in the region of the shell surface, specifically at least in a peripheral 
region serving for conveying the blank 11. Preferably, the suction air is 
here brought up to the blank 11 via the perforated belts 27, 28 so that 
the blank 11 is already decisively transported by the perforated belts 27, 
28 in the region of the deflecting roller 29. 
In this embodiment, the deflecting roller 29 consists of a hollow cylinder 
44 which is mounted rotatably on a fixed supporting axle 45. This has, at 
the same time, the task of supplying vacuum to the deflecting roller 29. 
The hollow cylinder 44 is equipped with radially directed suction bores 46 
which respectively open onto the shell surface of the hollow cylinder 44 
in the region of the suction holes 36 in the perforated belts 27, 28. The 
suction bores 46 are connected to a vacuum system in the supporting axle 
45, namely to a segmental groove 47 extending in a peripheral direction in 
the region of the suction bores 46. This is arranged and calculated so 
that the suction bores 46 are connected to the segmental groove 47 over 
the region of transport for the blank 11. This segmental groove is, in 
turn, connected via a radial bore 48 to a central axial bore 49 in the 
supporting axle 45. Consequently, by connecting the latter to a vacuum 
source, the segmental groove 47 is subjected constantly to suction air. 
The blank 11 is taken over by the deflecting roller 29 in the upper region 
of the latter in the closest proximity to the suction drum 17. Conveyance 
on the deflecting roller 29 extends approximately along a quarter circle. 
The design of the transport apparatus described this far permits a 
favourable arrangement of the conveying members, in such a way that the 
sheet of material and blanks are transported, until they are received by 
the perforated belts, on arcuate tracks adjoining one another. For this 
purpose, in the embodiments according to FIGS. 1 to 8, the deflecting 
roller 29, suction drum 17 and drawing roller 16 are arranged above one 
another in a common axial plane. As a result, a favourable synchronous 
drive of these conveying members is also possible, as is evident 
especially from FIG. 5. The suction drum 17 and deflecting roller 29 are 
directly engaged operatively with one another via gear wheels 50, 51. A 
further gear wheel 52, serves for driving the drawing roller 16. The 
suction drum 17 is mounted at both ends on a continuous axle 53. Here, the 
supporting axle 45 of the deflecting roller 29 is mounted on one side. 
The embodiment according to FIGS. 6 to 8 is, in principle, designed in the 
same way as that according to FIGS. 1 to 5. Here, the blank 11 is fixed to 
the upper deflecting roller 29 by means of suction air in a different way. 
As is evident especially from FIG. 6, the suction box 34 provided here is 
prolonged into the region of the deflecting roller 29, specifically by 
narrow suction segments 54, 55, shaped in the form of circular arcs and 
adjoining the suction box 34. These are designed, here, as relatively 
narrow trough-like air-conveying members of actually U-shaped 
cross-section. The fixed suction segments, 54, 55 extend in 
correspondingly shaped and dimensioned peripheral grooves 56 and 57 
respectively in the deflecting roller 29. The differences in dimension are 
selected so that the deflecting roller 29 is freely rotatable relative to 
the suction segments 54, 55. The radially outer side of the suction 
segments 54,55 is open, thus forming a suction slit 58. 
In the embodiment according to FIG. 7, the suction segments 54 extend 
underneath the perforated belts 27, 28, namely in the region of the air 
suction holes 36. Here, therefore, in a way similar to the embodiment 
according to FIGS. 1 to 5, the perforated belts 27, 28 are subjected to 
suction air in the region of the deflecting roller 29 also, so that they 
can even here fulfil their conveying and fixing function in relation to 
the blank. 
In the embodiment according to FIG. 8, fixing of the blank and the 
conveyance thereof are separated from one another in the region of the 
deflecting roller 29. Here, the suction segments 55 are arranged offset 
laterally, namely inwards, in relation to the perforated belts 27, 28. For 
this purpose, the suction segments 55 terminate essentially flush with the 
shell surface of the deflecting roller 29, so that here the suction slits 
58 can act directly on the blank 11. 
Moreover, here, the conveying members 16, 17, 29 are in the same or similar 
positions relative to one another as in the embodiment previously 
described. The suction box 34 is designed in a similar way to the suction 
chambers 32, 33 as regards the guidance of the perforated belts 27, 28. 
FIG. 9 shows an alternative embodiment in which the blanks 11 produced 
likewise by means of a severing cut on the suction drum 17 are transferred 
directly by the suction drum 17 to the perforated belts 27, 28 in the 
region of the (vertical) conveying side 31. For this purpose, the suction 
drums 17 is mounted underneath the upper deflecting roller 29 closely 
adjacent to the perforated belts 27, 28 in the upper region of the 
conveying side 31, in such a way that the blanks 11 running off from the 
periphery of the suction drum 17 are transferred directly to the conveying 
side 31 of the perforated belts 27, 28. 
Located in front of the suction drum 17 in the conveying direction is a 
separate additional feed roller 59 which is located approximatly 
underneath the suction drum 17 and, as a result, provides the sheet of 
material 14 and the blank 11 with a generally larger surface of contact 
against the suction drum 17 (approximately three quarters of the 
periphery). The drawing rollers 15, 16 are arranged correspondingly offset 
laterally, specifically above the deflecting roller 29. An especially 
accurate and fault-free guidance of the sheet of material 14 and 
consequently of the blank 11 is thereby guaranteed even at high speeds. 
Moreover, the perforated belts 27, 28 and deflecting roller 29 have a 
similar design to those of the preceding embodiments.