Apparatus for supplying a stack of carton blanks form a pallet to the magazine of a carton-packing machine

An apparatus for supplying a stack of carton blanks from a pallet to the magazine of a carton-packing machine in which the carton blanks are arranged vertically adjacent to each other, in particular for the tobacco industry, comprises an unloading carriage which is pivotable about a horizontal axis from a substantially vertical position into a substantially horizontal position and has an unloading fork which is movable along the unloading carriage and the prongs of which in the vertical position of the unloading carriage and thus in the horizontal position of the unloading fork can be inserted beneath the stack into the gaps between the boards at the upper side of the pallet. A drive displaces the unloading carriage and thus the prongs in the direction of the gaps between the boards at the upper side of the pallet; a retaining device provided on the unloading carriage holds, in the substantially horizontal position of said unloading carriage, the stack of carton blanks in the vertical position; a conveyor for the transfer of the individual blanks from the unloading carriage to the magazine is integrated into the unloading carriage.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates to an apparatus for supplying a stack of carton 
blanks from a pallet to the magazine of a carton-packing machine in which 
the carton blanks are arranged vertically adjacent to each other. 
2. Description of the Prior Art 
In particular in the tobacco industry, but also in other fields of packing 
technology, carton blanks are delivered on pallets in such a manner that 
the folded-out, still flat carton blanks are stacked horizontally one 
above the other. The individual blanks are then removed from this stack 
and supplied to the magazine of the carton-packing machine. 
Attempts have already been made to automate the individual steps of the 
blank supply; thus German Offenlegungsschrift 3,001,733 discloses an 
apparatus for filling a blank magazine with carton blanks in which a 
reserve magazine with a stack of horizontally disposed carton blanks is 
arranged vertically above the actual magazine of the carton-packing 
machine. From the stack of the reserve magazine the individual carton 
blanks drop vertically downwardly into the magazine so that the latter is 
continuously filled with carton blanks up to a predetermined height. This 
apparatus is not suitable for transferring carton blanks from a pallet. 
Furthermore, published European patent application 33,799 discloses an 
apparatus for removing carton blanks from a blank stack in which the 
entire blank stack including its support is pivotable about a horizontal 
axis so that the individual carton blanks are disposed on each other and 
thereby spread out in the manner of a fan. The respective lowermost carton 
blank lies on a conveying means so that the carton blanks are carried away 
individually from below and placed on a stack from where they are again 
individually withdrawn from below. However, this apparatus also cannot be 
used to transfer a stack of carton blanks from a pallet because the 
necessary pivot movement of the pallet with the blank stack is 
problematical. In addition, this apparatus requires a lot of space. 
It is therefore still usual to remove individually by hand carton blanks 
arranged in a stack on a pallet and to place said blanks in vertical 
position into the magazine of the carton-packing machine. This manual 
loading is, however, tedious and complicated; in addition, the working 
speed of the carton-packing machine can vary at any time because it 
depends inter alia, on the production speed of the product to be packaged 
and is influenced, for example, by production interruptions. There is no 
continuous predetermined rhythm for feeding the carton blanks to the 
carton-packing machine so that the magazine must be constantly observed 
and filled up again when necessary. 
SUMMARY OF THE INVENTION 
The invention is therefore based on the problem of providing an apparatus 
for supplying a stack of carton blanks from a pallet to the magazine of a 
carton-packing machine in which the aforementioned disadvantages do not 
occur. In particular, an apparatus is to be proposed which can be 
integrated into the carton-packing machine and when necessary 
automatically loads the magazine of the carton-packing machine with the 
carton blanks from the pallet. 
The invention solves this problem by an improvement comprising 
an unloading carriage pivotable about a horizontal axis out of a 
substantially perpendicular position into a substantially horizontal 
position and having an unloading fork movable along the unloading 
carriage, 
the prongs of said fork in the vertical position of the unloading carriage 
and thus in the horizontal position of the unloading fork being insertable 
beneath the stack into the gaps between the boards at the upper side of 
the pallet, 
a drive means displacing the unloading carriage and thus the prongs of said 
fork in the direction of the gaps between the boards and the upper side of 
the pallet, and 
a conveying means integrated into the unloading carriage for the transfer 
of the individual blanks from the unloading carriage to the magazine. 
Expedient embodiments are defined by the features of the subsidiary claims. 
The advantages achieved with the invention are based on the fact that by 
means of a very compact apparatus, thus requiring only little space, the 
blank stack is lifted from the pallet, pivoted through 90.degree. and 
thereby brought into such a position that the individual carton blanks now 
held in the vertical position, i.e. a position exactly plumb to the earth, 
can be supplied to the magazine of the carton-packing machine individually 
and thus in accordance with the requirements. By corresponding conception 
of the travelling movement of the unloading carriage in conjunction with 
the conveying means for the pallet it is also possible to lift two blank 
stacks consecutively off the pallet. After removal of the second blank 
stack the pallet must be replaced by a new pallet with blank stacks. 
Adequate time is available for this purpose, especially since the actual 
supply apparatus serves as a sort of buffer between the blank supply on 
the pallet on the one hand and the magazine of the carton-packing machine 
on the other, i.e. the new pallet must arrive in the removing position at 
the latest when (a) all the blanks have been taken from the buffer and (b) 
the magazine of the carton-packing machine is also substantially empty. 
As mentioned, it is expedient to place each pallet on a conveying means, 
generally roller conveyors, so that the pallet can be brought into the 
actual removal position. For aligning the or each pallet in the removal 
position, centering rails and a transverse pushing means are provided on 
the conveying means which push the pallets during their transport 
perpendicularly to their transport direction and bring said pallet exactly 
into the removal position. 
In this position the prongs of the removal fork, the dimensions and spaces 
of which are adapted to the gaps between the boards in the upper side of 
the pallet, engage into the clearances formed by the gaps between the 
lowermost blank of the stack and the pallet so that the blank stack as a 
whole can be lifted off the pallet, transported away and finally pivoted 
by a pivotal movement of the removal carriage about approximately 
90.degree. into a position in which the individual blanks of the stack are 
in the vertical position. The blanks are then held on one side by the 
removal fork and on the opposite side by a retaining means which can be 
formed for example by a pneumatically actuable cylinder or by a retaining 
roller. 
When a cylinder is used, said cylinder is lifted in accordance with the 
demand for blanks by the carton-packing machine so that the respective 
foremost carton blank drops forwardly into the magazine of the 
carton-packing machine. It must be ensured here that not all the carton 
blanks fall forward at the same time; consequently the cylinder is moved 
forwardly only a certain distance synchronously to the rhythm of the 
machine and entrains at least the foremost carton blank whilst the 
remaining carton blanks are retained by a further retaining means, for 
example a brush lying on the upper edge of the carton blanks. 
With this construction of the retainIng means, in a preferred embodiment 
the unloading carriage is not pivoted into the horizontal position but is 
kept in a somewhat inclined or oblique position in which the carton blanks 
engage by their own weight the unloading fork. 
It is alternatively possible to pivot the unloading carriage into the 
horizontal position so that the foremost carton blanks assume a slightly 
inclined or oblique position wIth respect to the vertical and bear on the 
retaining roller. 
If the conveying means provided at the unloading carriage, generally a 
conveying belt, is now set in motion the lower edge of the foremost carton 
blanks will be entrained and said blanks will drop down below the 
retaining roller onto the conveying means of the magazine of the 
carton-packing machine.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The apparatus shown in the Figures and denoted generally by the reference 
numeral 10 serves for supplying one stack 12 of carton blanks from a 
pallet 14 to the magazine 16 of a carton-packing machine (not shown) and 
comprises a base 18 into which a roller conveyor 20 with driven rollers is 
integrated. On the roller conveyor 20 (see FIG. 2) a pallet 14 having two 
stacks of dispatch-carton-blanks can be deposited by means of a driverless 
transport system, a fork truck or lifting truck and then brought into the 
removal position shown in the Figures. 
In the base 18 a chain drive 22, indicated schematically in FIG. 1, for a 
removal means 24 is arranged parallel to the conveying direction of the 
pallet 14 with the two blank stacks 12 on the roller conveyor 20 so that 
the removal means 24 can be reciprocated parallel to the conveying 
direction of the pallets 14 adjacent the roller conveyor 20. 
The removal means 24 comprises a base member 26 coupled to the chain drive 
22 and having two vertical supports 28 which at their upper ends carry an 
unloading carriage 32 pivotable about a horizontal axis 30. As apparent 
from FIG. 1 the unloading carriage 32 is formed substantially by a 
frame-like structure which at one end, the upper end in the illustration 
of FIG. 1, is formed with a projecting rod 35 which carries a rod 37 
projecting perpendicularly to rod 35 and having a retaining roller 38 
still to be explained. 
At the opposite end an unloading fork 34 projects perpendicularly from the 
frame-like structure of the unloading carriage 32 and in the embodiment 
illustrated has four prongs 36 (see FIG. 3), the spacings and dimensions 
of which are adapted to the gaps between the boards at the upper side of 
the pallet 14. The pallets 14 are standardized industrial and Euro 
pallets; both types of pallets can be used on the apparatus by 
correspondingly adapting the pitch of the fork and the pallet delivery. 
The unloading fork 34 can be moved in the direction shown by arrow 39 in 
FIG. 4 by means of a spindle drive indicated schematically in FIG. 5 along 
the frame-like structure of the unloading carriage 32, the guidance being 
via a linear ball bushing (not shown). In the position of the unloading 
carriage 32 shown in FIG. 1 this displacement of the unloading fork 34 
results in a movement upwardly or downwardly whilst in the pivoted 
position of the unloading carriage 32 a substantially horizontal movement 
of the unloading fork 34 results. 
Furthermore, a conveying means 40 indicated schematically in FIGS. 8 and 9 
formed, for example, by a conveying belt is integrated into the unloading 
carriage 32 and furnishes a transport movement in the plane of the 
unloading carriage 32 as indicated by the arrows in FIGS. 8 and 9. 
On the apparatus 10, in particular on the actual removal means 24, various 
sensors, generally light barriers, are provided and control the individual 
functions in a manner still to be explained. 
As apparent from FIG. 4 a schematically indicated pallet-centering device 
comprising a transverse pushing means 42 is integrated into the roller 
conveyor 20 so that the pallets 14 placed on the roller conveyor 20 can be 
shifted perpendicularly to their conveying direction and thereby brought 
into the correct removal position. The transverse pushing means 42 can be 
adjusted via a spindle drive (not shown). 
Hereinafter the mode of operation of the embodiment according to FIGS. 1 to 
8 will be discussed. 
As already mentioned, at the beginning one pallet 14 with two blank stacks 
12 is placed on the roller conveyor 20 and then brought by means of the 
roller conveyor 20 on the one hand and the transverse pushing means 42 on 
the other into the removal position shown in the Figures. In FIG. 1 the 
removal position of the pallet 14 is represented by a single stack 12, 
rendering visible the horizontal prongs 36 of the removal fork 34 with the 
removal carriage 32 in the vertical position. 
As soon as the pallet 14 with the blank stacks 12 has reached the removal 
position, as can be monitored if necessary by sensors (not shown), the 
removal means 24 with the removal carriage 32 is also in the position 
apparent from FIGS. 1 and 2, i.e. the prongs 36 of the removal fork 34 lie 
in a horizontal plane at the level of the gaps between the upper boards of 
the pallet 14. The base member 26 of the removal means 24 is now displaced 
to the right in accordance with the illustration in FIGS. 1 and 2, the 
prongs 36 thereby moving into the gaps between the upper boards of the 
pallet 14 and beneath the left blank stack according to the illustration 
of FIG. 2, as shown in FIG. 5. A light barrier 44 (see FIG. 3) monitors 
this movement and responds when the leading edge of the stack 12 reaches 
the end of the prongs 36. 
On removal of the right blank stack 12 shown in FIG. 1 the removal means 24 
must of course move further to the right until the prongs 36 are located 
beneath said stack 12. 
The lifting means for the unloading fork 34 is now briefly set in operation 
so that the prongs 36 and thus also the left stack 12 of carton blanks are 
raised just above the upper edge level of the pallet 14. After raising of 
said stack 12 the removal means 24 again moves to its left end position 
shown in FIG. 6 so that the left stack 12 is now located adjacent and 
above the pallet 14. Then the lifting means is again set in operation so 
that the unloading fork 34 moves upwardly until the uppermost blank of the 
stack 12 has reached the highest position for pivoting and approaches the 
retaining roller 38 as shown in FIG. 7. This actual position is detected 
by means of a light barrier 46 indicated in FIG. 7. 
In this upper end position the unloading carriage 32 is now turned 
counterclockwise as in the illustration of FIGS. 8 and 9 into a 
substantially horizontal position so that the individual carton blanks of 
the stack 12 assume substantially a vertical position; the carton blank 
which has formed the bottom of the stack 12 on the pallet 14 now lies on 
the vertical prongs 36 of the unloading fork 34 whilst the uppermost 
carton blank bears on the retaining roller 38 and is held in an 
approximately vertical position. 
In the horizontal position of the removal carriage 32 shown in FIG. 8 the 
horizontal lower edge of the blank stack 12 is somewhat above the 
conveying means of the magazine 16 of the carton-packing machine. 
The individual blanks of the stack 12 are also arranged vertically in said 
magazine 16. The conveying direction of the blanks in the magazine 16 is 
indicated in FIGS. 8 and 9 by the arrow. 
Associated with the trailing edge of the stack 12 in the magazine 16 is a 
light barrier 47 which responds when the individual blanks in the magazine 
16 have been removed to such an extent that the light beam of the light 
barrier 47 is no longer interrupted; this is an indication that blanks can 
again be supplied to the magazine 16 from the unloading carriage 32. 
At this instant the conveying means 40 integrated into the unloading 
carriage 32 is actuated so that the lower edges of the blanks of the stack 
12 are entrained and drop downwardly past the front edge of the conveying 
means 40, thereby the upper edges of the blanks slipping past the 
retaining means 38 move downwardly onto the convey means of the magazine 
16. As soon as these new blanks have arrived the light barrier 47 responds 
again so that the conveying means 40 of the unloading carriage 32 is again 
stopped and thus the replenishment of the blanks is interrupted. 
Synchronously with the movement of the conveying means 40 the unloading 
fork 34 is displaced to the left in the illustration of FIG. 8 until all 
the blanks have been transferred from the conveying means 40 of the 
unloading carriage 32 onto a conveying means of the magazine 16. The light 
barrier 44 provided at the unloading fork 32 detects the transfer of the 
last blank; as soon as said light barrier 44 responds thereto and the 
light beam of the light barrier 47 is not interrupted the unloading fork 
34 is again driven into the right position according to the illustration 
of FIG. 8 and the unloading carriage 32 is pivoted back to its vertical 
position so that the starting position according to FIGS. 1 and 2 is again 
reached. 
The right blank stack 12 according to the illustration in FIG. 1 can now be 
lifted in corresponding manner, only with associated greater displacement 
of the removal means 24, pivoted and then supplied to the magazine 16. 
FIG. 9 shows a modification of the retaining means for the left end of the 
stack 12 according to the illustration of said FIG. 9. In this case the 
retaining roller 38 is replaced by a pneumatically actuable cylinder 49 
which can be reciprocated in the direction of the double arrow and is 
inserted in each case behind the foremost blank or at least behind the 
foremost blanks to supply them to the magazine 16 in conjunction with the 
displacement by the conveying means 40. 
To prevent the unintentional sliding-up of the other blanks of the stack 12 
a brush 48 bears on the upper edges of the front blanks and retains the 
other blanks of the stack 12 not engaged by the cylinder 49. 
As soon as the second blank stack 12 has been raised, too, the empty pallet 
14 is moved back on the roller conveyor 20 to the transfer point and a 
command for pallet exchange is generated or displayed; said pallet is then 
engaged by the driverless transport system, a fork truck or a lifting 
truck, and replaced by a new pallet 14 with two blank stacks.