Method of and apparatus for the wrapping of palletized units

A pallet unit consisting of a stack of articles on a pallet is wrapped both vertically and horizontally with a foil band by orbiting a wrapping satellite in a vertical plane while the unit is supported on a pair of support arms which pass through the orbit for vertical wrapping and the orbit is swung into a horizontal position and raised and lowered for horizontal wrapping of the unit. The vertical wrapping is only effected along two vertical sides of the stack and the foil wrap passes between the skids of the pallet.

CROSS REFERENCE TO RELATED APPLICATION 
This application is related to my copending application Ser. No. 07/712,156 
filed Jun. 6, 1991. 
FIELD OF THE INVENTION 
My present invention relates to a method of wrapping a stack of articles on 
a pallet, hereinafter referred to as a palletized unit, with a foil band. 
The invention also relates to an apparatus for carrying out this method 
and, in particular, to an apparatus which has a frame upon which at least 
one satellite can orbit as driven by a motor and which holds a supply of 
the foil band and, under tension resulting from the braking of the supply 
of the foil, can wind that foil around the palletizec unit. The principles 
of wrapping a foil around an article such as a palletized unit with 
braking of the foil supplied, are discussed in the above mentioned 
copending application. 
BACKGROUND OF THE INVENTION 
Systems wherein a stack of articles or goods upon a pallet can be packaged 
by wrapping a foil around therein substantially horizontally in a 
generally spiral pattern or in annular sections so that the foil will 
extend around the vertical sides of the palletized unit are, of course, 
known. The foil bands which are used are generally so called stretch foils 
which are already prestretched and thus have been strengthened by a 
stretching process. 
The apparatus for applying such foil wraps can comprise a substantially 
toroidal frame which is vertically displaceable and carries a support ring 
which can extend in a horizontal plane. A rotating ring can be driven 
about a vertical axis on the support ring and can carry a satellite 
provided with means for receiving a roll of the foil band and a means for 
braking the delivery of the foil from that roll. 
For the winding operation, the support frame is initially lowered to its 
bottom-most position and a free end of the foil band is applied to the 
stack. The satellite is then caused to orbit the stack as the support 
frame is gradually raised so that, as the satellite orbits the stack in a 
generally helical pattern, the foil band will be wrapped around the 
vertical sides of the stack and, because the delivery of the foil is 
braked, an additional stretch will be applied to the foil which thus 
engages the stack of articles under tension. 
To avoid shifting of the articles of the stack it is also known to provide 
a fixing plate on the apparatus which can be lowered onto the top of the 
stack to hold the articles in place as the foil is wrapped therearound. 
Furthermore, a cover sheet applying device can be provided which can 
overhang the top of the palletized unit in an outrigger fashion to apply a 
foil sheet to the stack which can be held in place by the last turns of 
the foil band. 
A drawback of this wrapping method is that it does not always ensure a good 
connection between the stack of articles and the pallet. Furthermore, the 
wrapping system does not provide a residual vertical force on the stack 
which can assist in holding the articles against one another and against 
the pallet. 
It is also known to wrap palletized units with substantially vertical turns 
of foil which pass over the head and under the foot of the unit and also, 
therefore, are wound around the vertical sides thereof. After winding the 
palletized unit in the vertical direction along two vertical sides, the 
unit is rotated through 90.degree. about its vertical axis and the foil 
wrap is then applied in a direction crosswise to the first direction, also 
in the vertical sense so that all six sides of the unit will be wrapped. 
In this method, a vertical stress is applied to the stack of articles to 
hold the stack against the pallet and the articles of the stack against 
one another. However, in this case, the positioning of the articles in the 
horizontal direction is not always satisfactory. Indeed, horizontal 
shifting of the articles frequently cannot be avoided. 
Furthermore, this latter method results in winding of the foil wrap around 
the skids of the pallet so that frequently the packaged unit cannot be 
transported by means of a manually operated lift or, for that matter, a 
mechanically driven forklift. In transportation of the palletized wrapped 
unit there is always the danger that the foil segments in the region of 
the skids will be damaged or ruptured and hence the connection of the 
stack of articles to the pallet will be weakened or broken. 
OBJECTS OF THE INVENTION 
It is, therefore, the principal object of the present invention to provide 
a method of packaging a palletized unit of the type described whereby the 
aforementioned drawbacks are eliminated. 
A more specific object of the invention is to provide an improved method of 
packaging a palletized unit with a foil wrap whereby horizontal shifting 
of the articles or goods of the stack is precluded in a highly effective 
manner and simultaneously a good connection is ensured between the stack 
and the pallet without interfering with the ability to transport the unit 
to lift or otherwise handle the unit utilizing conventional pallet 
handling equipment, such as a forklift truck or a manual palletized-goods 
transport. 
Another object of the invention is to provide an improved apparatus for 
wrapping a palletized unit so that the resulting package is more reliable 
and less prone to damage in the transporting of the package unit. 
SUMMARY OF THE INVENTION 
These objects and others which will become more readily apparent 
hereinafter are attained, in accordance with the invention, in a method of 
packaging a stack of articles on a pallet forming a palletized unit, the 
palletized unit comprising a top formed by the stack, vertical sides 
formed by the stack, and a bottom adapted to support the unit, the pallet 
having skids along the bottom extending parallel to a first pair of the 
sides and being accessible to a fork for lifting and moving the unit at a 
second pair of the sides, the method comprising the steps of: 
(a) wrapping the unit substantially horizontally by winding a foil band in 
a plurality of generally horizontal turns around the sides; and 
(b) wrapping the unit substantially vertically by winding a foil band 
around the unit in a plurality of generally vertical turns from the top to 
the bottom and along one of the pairs of the sides. 
This method, in which the palletized unit is wrapped substantially 
horizontally around all of its vertical sides and is wrapped substantially 
vertically over the head and foot or top and bottom of the unit and over 
at least one pair of opposite vertical sides has been found to provide 
surprising advantages over the conventional methods described. On the one 
hand, it ensures a reliable connection between the pallet and the stack of 
articles and goods while, on the other hand, it ensures that a lateral or 
horizontal slip of individual layers of the articles will be avoided. 
The improved package also is completely protected from the weather without 
the need for a special device for covering the stack. Since the vertical 
wrap can be applied effectively only along two sides of the package 
essentially parallel to the skids, local damage to sections of the foil 
can be avoided or, at the very least, damage to the foil in transporting 
the unit can be greatly reduced by comparison to earlier methods. One of 
the great advantages of the system of the invention is that the horizontal 
wrap cannot be effected by the engagement of a fork or other lifter with 
the bottom of the unit and thus at least the horizontal wrap will remain 
intact even though there might be some damage to the vertical wrap from 
the handling of the pallet unit. 
An advantage of the invention is, moreover, that the changes of the 
sequence in which the steps of the method can be carried out, can be 
selected to satisfy the particular needs. For example, if the connection 
between the stack and the pallet and thus the vertical wrap is most 
important for a particular palletized unit, I initially will apply the 
horizontal wrap and thereafter the vertical wrap. In this manner, the 
horizontal wrap serves to presecure the stack in place so that, in 
application of the vertical wrap, a significantly higher foil tension can 
be applied. 
When, however, for a particular packaged unit it is more important to 
secure the layers against shifting in the horizontal sense, I prefer to 
apply the vertical wrap first to presecure the stack and the pallet and 
then to wrap the unit horizontally so that, for the horizontal wrap a 
higher pretension can be applied to the foil than is the case, for 
example, in conventional methods of horizontal wrapping. The method of the 
invention, therefore, increases the possibility of combining the 
advantages of the two wrapping steps. 
According to a feature of the invention, the pallet unit is wrapped 
exclusively in parallel to the skids of the pallet in the vertical 
wrapping step. In this manner, the foil band segments running along the 
bottom of the unit can be disposed exclusively between the skids although 
the vertical turns can spread out outwardly to cover the entire top of the 
stack. Thus a space is maintained between the skids to enable the wrapped 
palletized unit to be handled with a manual carrier or transporter in a 
particularly advantageous manner. 
Since the foil band in the region of the foot of the palletized unit is 
disposed exclusively between the skids, there is less danger of damage to 
the vertical wrap and hence any likelihood toward loosening of the 
connection between the stack and the pallet can be reduced. 
For this vertical wrapping step, the pallet unit can be moved horizontally 
and transverse to the direction of elongation of the skids so that the 
foil band can pass, in the region of the foot of the unit, between the 
skids of the pallet while over the remaining portions can spread uniformly 
over the stack. In this manner, the head of the unit can be completely 
covered and thus the vertical prestress applied by the stretched vertical 
wrap can be distributed over the entire area of the top of the unit. 
In addition, this wrapping technique applies diagonally effective prestress 
to the wrapped package affording additional security against slipping of 
the load upon the pallet. 
While the vertical horizontal wrapping can be effected in two different 
devices provided respectively for the vertical and horizontal wrapping and 
with transfer of the partly wrapped package from one device or apparatus 
to the other, I can provide a single apparatus especially intended to 
carry out the method of the invention with its two distinct wrapping 
modes. 
According to the invention the support for the satellite or satellites is 
swingable into a horizontal plane and into a vertical plane, selectively, 
so that the orbit of the satellite can lie in either plane. The apparatus 
thus permits selectively a vertical and a horizontal wrapping of the 
pallet units by simply swinging the orbit or circulatory travel path of 
the satellite or satellites through 90.degree. from one position to the 
other. In this case, any need to transport the unit between two wrapping 
stations is avoided. 
With the apparatus of the invention, the satellite or the satellites are 
preferably mounted to orbit on a support frame which is swingably mounted 
about a horizontal axis on one side of a support upon which that frame can 
be vertically raised and lowered. It has been found to be especially 
advantageous to provide the satellite or satellites on a rotating ring 
which is rotatably mounted on the support ring. This configuration has 
been found to simplify essentially the vertical wrapping of the pallet 
unit. 
According to a further feature of the invention, the apparatus includes a 
carriage provided with a support arm which is cantilevered on the carriage 
and can engage the palletized unit for displacing same into position 
beneath the support ring and which can pass through the support ring and 
rotating ring of the satellite for the horizontal and vertical wrapping of 
the palletized unit, respectively. By corresponding back and forth 
movement of the carriage, moreover, I can ensure that as the band passes 
downwardly to the bottom of the palletized unit, the unit can be shifted 
to ensure that the band will pass only between the skids in the manner 
described previously. After the vertical wrapping of the unit, the 
carriage can be withdrawn, e.g. after the palletized unit has been 
deposited upon a transfer device capable of forwarding the palletized unit 
to a conveyor or the like. 
The cantilevered support arm can be provided with a vertical spacing above 
the track for the carriage or the surface upon which the carriage is 
displaced, in the vertical position of the satellite orbit, to permit the 
satellite to travel with the support arm and the surface therebeneath. 
This greatly simplifies the configuration of the carriage and its path or 
guide surfaces. 
According to a feature of the invention, the apparatus comprises a support 
table for the pallet unit which can be provided with means for shifting 
the pallet unit perpendicular to the plane of the satellite orbit in its 
vertical position. The transport means simplifies the placing of the 
pallet unit upon the support arm of the carriage. The support table can be 
vertically displaceable and can have a width significantly less than the 
free spacing between two support arms of the carriage.

SPECIFIC DESCRIPTION 
The coiling apparatus 1 shown in the drawing comprises a portal-like frame 
member 2 having two uprights 3 and a cross-piece 4, only the front upright 
3 being 5 visible in FIGS. 1-5. The frame or support 2 is fixed on the 
foundation or round 30 and constitutes a post as mentioned previously. 
On each of the uprights 3, a respective slide 5 is vertically shiftable by 
a means represented at 31 in FIG. 6 and constituting a vertical shifter of 
the type conventional in wrapping mean capable of horizontally wrapping 
the palletized unit (see, for example, the aforementioned copending 
application). In the two slides, the two ends of a U-shaped support frame 
6 are pivotally connected on respective pivots 7 defining a horizontal 
pivot axis 32. The free ends can be formed as gear segments 8, each of 
which meshes with a pinion 9 which can be driven by electric motors as 
represented diagrammatically at 33 in FIG. 3 to enable the support frame 6 
to be swung from the vertical plane as shown in FIGS. 1-3 into the 
horizontal plane of FIGS. 4 and 5 and vice versa. 
On the underside of the support frame 6 is suspended a circular support 
ring 10 which defines a track for a rotating ring 11 mounted therebelow. 
On the ring 11 at least one satellite 12 can be mounted and can carry a 
roll of the foil to be wound around the stack and a brake device, also 
represented at 12 utilizing, for example, the principles of the 
aforementioned application. 
Opposite the coiling unit formed by the roller foil and its foil brake 12 
on the ring 11 is a counterweight 13 to compensate for the mass of the 
coiling unit. Instead of the counterweight 13 a further satellite coiling 
unit can be provided so that the stack can be represented simultaneously 
with two foil bands. 
Below the support frame 6 in the horizontal position therefore (see 
especially FIGS. 4 and 5) is a support table 14 (FIG. 6) equipped with a 
conveyor belt which can be displaced via a drive wheel 16. As can be seen 
from a comparison of FIGS. 1 and 2, a palletized unit 17, comprised of a 
pallet 18 and a stack 19 of articles on the pallet, can be delivered to 
the support table 14 from a conveyor unit 20 by driving the belts of this 
conveyor unit and the support table 14. 
The coiling apparatus also comprises a carriage 21 which has a travelling 
undercarriage 22 and, at its rear end, a support frame 23 from an upper 
side of which project cantilevered support arms 24. The width of the 
carriage is such that it can pass between the uprights 3 of the portal 
frame 2 of the apparatus. The undercarriage 22 can travel via wheels on 
tracks 34 (see FIG. 6) inwardly of the posts 3. 
The apparatus can effect a wrapping operation as follows: 
Before the palletized unit 17 is advanced into the wrapping apparatus 1, 
the support frame 6 with its support ring 10 and rotating ring 11 is swung 
downwardly into its vertical orientation (FIG. 1). 
The carriage 21 is then shifted to the left so that its cantilevered arms 
24 above the undercarriage 22 pass over the support frame 6 while the 
undercarriage 22 passes below the support frame. The support frame 6 with 
its support ring 10 and rotatable ring 11 thus lie between the arms 24 and 
the undercarriage 22. The support table 14 thus lies in the plane of the 
conveyor 20 and below the plane of the arms 24. The pallet unit 17 is 
displaced onto the support table 14 so that the arms 24 can engage through 
holes or gaps 35 in the skids 25, 26, 27 of the pallet 18. The support 
table 14 is then lowered by means of a table lowering device represented 
only at 36 in FIG. 3 so that the pallet unit 17 comes to rest on the 
support arms 24. 
In FIG. 7, I show that the skids, for example, the skid 25, can be 
interrupted at 37 to accommodate the arms 24 and further that, between the 
skids, channels 38 can be provided in the underside of the pallet to be 
spanned by the turns of the foil band 39 wrapped around the bottom of the 
pallet as will be described. 
When the pallet unit is seated on the support arms 24, the apparatus is in 
the position shown in FIG. 2. 
From the satellite 12, an end of the foil band is affixed on the pallet 
unit 17 and the ring 11 is set in rotation so that the satellite 12 will 
orbit the pallet unit. As a consequence, the pallet unit 17 is vertically 
wrapped. With slow displacement of the carriage 12, in the view shown in 
FIG. 2 to the right, the foil band is applied in a helical or spiral 
pattern around the pallet unit 17. 
The displacement of the carriage 21 is effected by an oscillating drive 
which, as the band is in position to undersling the unit, disposes the 
region between the skids 25, 26 and 27 in the path of the band so that the 
pallet 18 is vertically wrapped at its underside only between the pairs of 
skids 25 and 26, 26 and 27 respectively. The skids 25 to 27 remain free of 
the turns 39 of the foil passing around the bottom of the pallet on the 
upper surface of the pallet unit 17, however, the unit is so moved that 
the foil wrap is applied uniformly to completely cover the surface. 
After the vertical wrapping is complete (FIG. 3), the pallet unit 17 is 
withdrawn by the carriage 21 to the right out of the plane of the ring 11. 
The support frame 16 is then swung into the horizontal plane. Then the 
carriage 21 is shifted again to the left to place the partially wrapped 
unit 17 below the support 6, the ring 10 and the rotating ring 11 (FIG. 
4). The support table 14 is lifted to accept the pallet unit 17, whereupon 
the arms 24 are retracted (FIG. 5) and coiling is commenced by rotation of 
the ring 10 and lowering of the assembly 6, 10, 11, 12. A helical wrap is 
applied horizontally beginning from the upper edge of the stack 19. The 
stack can be wrapped downwardly and then again upwardly as desired. After 
the horizontal wrapping is complete, the support frame 6 is raised until 
the pallet unit 17 can be displaced by the table 14 onto the conveyor 20 
from which it can be transferred away from the apparatus. The carriage 21 
is then returned to its original position (FIG. 1) and a new pallet unit 
can be wrapped.