Method and a device for positioning cylindrical items

A method for rotating and orienting cans in a multipack configuration pushes the cans off a conveyor belt to a scanning and rotating stations where the cans are rotated until the sensors detect that the cans are facing the correct direction. The cans are then shifted back to the conveyor belt. This is useful to prevent unintentional reading of e.g. bar codes on a single item.

BACKGROUND OF THE INVENTION 
In today's distribution of e.g. beverages and food in cylindrical cans or 
bottles, in the text below referred to as cylinders, selling of 
multipacked products occurs. It happens, during these circumstances, that 
the multipack does not cover the EAN-code that each separate cylinder has 
in the multipack. An EAN-code is a bar code, which for example identifies 
the price of a product and the type of product. This code is used when one 
separate products is to be sold. At the same time, the multipack has a 
code, which is intended for the number of items in the multipack, e.g. six 
beer-cans. Randomly, it occurs that the multipack simultaneously shows two 
different codes, which both are readable. When handling the multipack at 
the cash register there is a risk that the multipack is registered as if 
one single item only has been sold. 
This problem has forced forth that e.g. a 12-pack of beer-cans must now be 
sold in a completely enclosed carton package, which must be seen as a 
certain waste of resources plus that the consumer is left with the waste. 
In order to minimize the quantity of packaging material required, several 
solutions have been presented to the market. All these solutions have the 
drawback that the codes on each specific item in the multipack are left 
fully visable and readable and the risk for errors when handling these 
multipacks at the cash register is greater than with the solutions 
presently used. An example of a multipack with a small quantity of 
packaging material is described in EP-A-0 496 807, in this text only 
referred to as a reference. 
In order to decrease the amount of packaging material in a good way at the 
same time eliminating the above problem, each specific can or bottle must 
be put in such an internal order that the markings, such as the EAN-codes, 
on the product packages of the cans or bottles are placed between each 
specific product package in such a way that these codes cannot be read 
from the outside but only the code on the multipack proper. It is also 
suitable that the product package is fixed in this position. This can be 
done with a small amount of adhesive between the product package and the 
carrying element or that the multipack or product package is so designed 
that rotation of the cans after the assembling of the carrying element 
over the product packages is made impossible. Alternatively, the cylinders 
can be turned so that the codes can be read one after the other. 
SUMMARY OF THE INVENTION 
The above problem is solved by the invention in that before one or more 
rows of product packages are provided with a carrying element, the 
cylindrical objects are rotated and stopped in a predetermined position. 
The cylindrical objects, which are provided with a mark or a marking 
readable by a choosen sensor, are placed upon a surface having low 
friction against the bottom of each cylinder, respectively. Somewhere on 
the jacket or the vertical side of each cylinder at least one stop or 
blocking beam is mounted. On the opposite side of the cylinder in relation 
to the stop there is placed either at least one rotating wheel or at least 
another stop. If a rotating wheel is used, this is placed on such a height 
relatively the stop that rotation of the cylinder can occur, when the 
distance between the contact-point, or contact-points, of the stop against 
the cylinder and the contact-point of the rotating wheel against the 
cylinder is less, or at the most, equal to the double radius of the 
cylinders, measured horizontally through the centre of the cylinder. The 
surface of the stop, which is in contact with the cylinder, has low 
friction, or at the highest, the same friction as the surface of the 
cylinder, while the rotation wheel has a high friction against the surface 
of the cylinder. 
The distance between the front edge of the stop and the front edge of the 
rotation wheel is, when placing the cylinders, greater than the diameter 
of the cylinder. The stop and/or the rotation wheel is then before the 
actual rotation moved so that the distance becomes less than, or at the 
most, equal to the diameter of the cylinder, i.e. the front edge of the 
rotation wheel is pressed against the cylinders. 
In such a case, when two stops are used, see above, the rotation wheel must 
be mounted either in connection with one of the stops or under the bottom 
of the cylinder. If two rows of cylinders are standing next to each other, 
one of the cylinder rows can function as a stop for the other cylinder 
row. 
The guidance of the rotation functions in such a way that a sensor, e.g. a 
photocell, reads a marking on a cylinder. This sensor controls the 
rotation stop of this cylinder in such a way that it stops the cylinder at 
the desired position. For each cylinder in a row, where carrying elements 
are to be mounted, there are a sensor and a rotation wheel. A computer 
controls each separate pair of sensor/rotation wheel to the desired 
position. Each cylinder can be programmed to get its own position. A 
suitable position for the sensor/cylinder marking is close to a stop. The 
number of cylinders that can be rotated at the same time in a row is 
suitably a multiple of different, actual packaging sizes. To produce a 
high capacity in a machinery several rows can be rotated/mounted at the 
same time, alternatively this is done in a single, elongate row. 
The choice of material for the stop and the rotation wheel, respectively, 
is determined by the demand for as much difference in friction as possible 
between the stop/cylinder and the rotation wheel/cylinder. Also the size 
of the contact surface between the stop/cylinder and the rotation 
wheel/cylinder is adjusted to get the best possible difference in 
friction. If good conditions in this matter are achieved, the rotation 
wheel will be able to rotate the cylinder and stop it with a good 
precision. It is necessary to be able to vary the difference in friction, 
along with the difference in material, weight, height, etc., with 
different kinds of cylinders. It is also necessary to be able to vary the 
placing of both the stop and the rotation wheel from what each separate 
product demands. For the reasons above, the machine that will be used for 
these operations is constructed in such a way that the stop and/or the 
rotation wheel can be moved towards each other, when the cylinders are in 
position for rotation. Further, the stop must be exchangeable in order to 
fit different diameters on different cylinders and the rotation wheel must 
be exchangeable in order to give different friction, diameter and size of 
the contact surface of the wheel against the cylinder. There can also be 
other reasons for the change of stop and rotation wheel. Both the stop and 
the rotation wheel can be adjusted sidewise, lengthwise and vertically. It 
can occur that the cylinders are moved lengthwise and/or sidewise before 
or after the rotation takes place.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
As shown in the drawings a device for rotation of three cylinder objects 1, 
1' and 1" is shown, according to a preferred embodiment. The drawings also 
show, with thicker lines, partly integral details, partly the position of 
the cylinder objects before and during the rotation thereof. According to 
the preferred embodiment the cylinder objects 1, 1', 1" are displaced 
90.degree. to the side relative to the movement direction that they had 
before the rotation, when they were transported forwards on a conveyor 
belt 11 in the direction marked with an arrow 6. When alternative 
embodiments are used, a suitable rotation wheel, which is in contact with 
the bottom surface of the cylinder objects, can naturally be used or the 
cylinder objects 1, 1', 1" do not have to be displaced sidewise before or 
in connection with their rotation. 
In FIGS. 1 and 2 the cylinder objects 1, 1', 1" are shown in a position, 
before which a movable stop 2 places them in the position for rotation, 
which is closer illustrated in FIGS. 3 and 4. FIGS. 1 and 2 also show 
examples of placing sensors 3, 3', 3", which read the markings 4, 4', 4", 
which have been placed on the surface area of the cylinder objects 1, 1', 
1". Further, a safety and removal beam 5 is shown. This device makes sure 
that the cylinder objects do not fall over, when being displaced from the 
position shown in FIGS. 1 and 2, to the position shown in FIGS. 3 and 4. 
Thereafter the beam 5 takes the cylinder objects back to the starting 
position on the conveyer belt 11 after rotation of the cylinder objects 
and mounting of the carrying element having been done. Hereby the cylinder 
objects are moved back from the position shown in FIGS. 3 and 4 to the 
position shown in FIGS. 1 and 2. It is, of course, also possible to mount 
the carrying element over the cylinder objects both before and after the 
sidewise displacement has occured. It is also possible that the movement 
of the rotation zone is attained as a continuation of the movement that 
brought the cylinders into the zone and this provided that the cylinders 
cannot be moved from their taken position after the rotation. 
The direction of the cylinder objects has in FIGS. 1 and 2 been marked with 
the arrow 6 and the movement of the stop 2 with an arrow 7. In FIGS. 3 and 
4 the cylinder objects 1, 1', 1" are shown in their position before 
rotation. This means that the stop 2 is in its front position. The sensors 
3, 3', 3" are activated by the markings 4, 4' and 4" and the movement beam 
5 is waiting in its back position. Rotation wheels 8, 8' and 8" rotate and 
transfer their rotation to the cylinder objects 1, 1' and 1". The sensors 
3, 3' and 3" are in different phases. The sensor 3 just reads the marking 
4 on the cylinder object 1, the sensor 3' has stopped the rotation of the 
cylinder object 1' in its intended position and the sensor 3" has not yet 
read the marking 4" on the cylinder object 1". The direction of rotation 
of the cylinder objects 1, 1' and 1" is shown with an arrow 9. To get the 
cylinder objects to rotate more easily they are placed upon a surface 10 
having low friction. 
A second embodiment of the invention, which is not shown on the drawing, is 
to move the cylinders perpendicularly towards the lengthwise direction of 
the row with e.g. a gripping means at the top to a surface provided with a 
stop. This surface with the stop is moved to the position of rotation and 
thereafter, without changing the relative position of the cylinders, to a 
mounting position of the carrying elements in direct connection. This 
embodiment of the invention differs from the earlier one in that a 
displacement is attained between rotation and mounting of the multipack.