Apparatus for applying labels to objects having a helically grooved gluine roller

An apparatus for applying labels to bottles or the like comprises at least one moveable gluing palette 7 which coacts with a rotary gluing roller 1 so as to be coated with glue, and which thereafter transfers the glue to a label 17 which is transported by the palette from a label magazine 11 to a gripper 12 which grips the glue-coated label and presses it onto a bottle 15. The outer cylindrical surface of the gluing roller is provided with helical grooves 2 which are kept filled with glue, and the outer layer 10 of each gluing palette is slightly elastic so that when the palette is urged into contact with the ridges 3 extending between the grooves on the gluing roller, parts of the outer layer will be pressed partially into the grooves so as to come into contact with the glue present in the grooves.

BACKGROUND OF THE INVENTION 
The present invention relates to an apparatus for applying labels to 
objects, such as bottles or the like, comprising at least one moveable 
gluing palette which is intended to coact with a rotary gluing roller so 
as to be coated with glue and thereafter to transfer glue to a label which 
is transported by the palette from a label magazine to a gripper which is 
intended to grip the glue-coated label and press the label onto the object 
concerned. 
Devices of the aforedescribed kind are used, among other things, to apply 
labels to bottles in breweries, soft-drink bottling plants and like 
plants, which require the labelling devices to operate at high speed. The 
majority of these devices include a rubber gluing roller, aluminium gluing 
palettes and an adjustable glue scraper which is operative in determining 
the thickness of the glue on the gluing roller. 
These known devices must be produced with extreme accuracy and any 
subsequent adjustments to the devices in operation must be effected very 
precisely, since, for instance, the gluing palettes may only partially 
penetrate the glue layer on the gluing roller without making contact with 
the outer surface of the roller itself, since such contact would force the 
glue layer carried by the roller out onto the edges of the palette. This 
would cause glue to splash or squirt onto the palette surroundings, and 
would also result in glue fastening to the front side of the labels, 
causing the labels to be drawn off the bottles. Loose labels which fasten 
to the gluing roller are difficult to remove and may result in damage to 
the roller, particularly when using foil labels, since such labels can 
cause wear on the roller when fastening between the glue scraper and the 
roller. A certain amount of wear can also be caused when the operator 
scrapes away labels that have fastened to the gluing roller with the aid 
of a sharp tool. 
Another serious drawback with the known apparatus is that labels which 
fasten between the glue scraper and the gluing roller are liable to 
prevent the application of a fresh layer of glue on the roller, meaning 
that subsequent labels will not be completely coated with glue and that 
these glue-depleted labels will not stick to the very fast moving bottles. 
This may make it necessary to remove from the production line a very large 
number of bottles which lack labels. 
Another factor is that the clearance between the gluing palettes and the 
gluing roller must not be excessive, since an excessive clearance will 
prevent the palettes from coming into contact with the glue, with the 
result that the labels will not be adequately coated. 
The known apparatus are thus very sensitive to non-roundness of the gluing 
roller and also to wear on said roller, and require precise and play-free 
journalling of the roller. 
DE-A1-3 131 164 describes a gluing machine or apparatus in which the gluing 
palettes are permitted to make contact with the gluing roller, wherein 
both the palettes and the roller are provided with mutually intersecting 
grooves. This arrangement, however, suffers several drawbacks, since, 
among other things, the ridges located between the grooves become coated 
with intersecting glue beads which are pressed out onto the edges of the 
palettes as the ridges come into contact with one another and splash down 
onto the surroundings and also result in glue fastening to the front side 
of the label. 
SUMMARY OF THE INVENTION 
The prime object of the present invention is to provide labelling apparatus 
with which the aforesaid drawbacks of known techniques are eliminated, 
among other things. 
The invention is based on the realization that this object are achieved 
when the gluing roller and the gluing palette can be constructed so that 
the palettes are able to contact the outer surface of the roller without 
causing glue to splash down onto the surroundings. In this way, the 
extremely high tolerance requirements of known apparatus, with which the 
palettes are only permitted to penetrate partially into the actual glue 
layer, are avoided. 
Accordingly, an apparatus in accordance with this invention is primarily 
characterized in that the cylindrical outer surface of the gluing roller 
is provided with grooves which are intended to be kept filled with glue; 
and in that at least the outer layer of each gluing palette is somewhat 
elastic so that when the palette is pressed into contact with the ridges 
located between the grooves on the gluing roller, parts of said outer 
layer will be pressed slightly into said grooves so as to come into 
contact with the glue present therein. 
By using, in accordance with the invention, a grooved gluing roller in 
combination with gluing palettes having an elastic outer layer, the 
palettes, although they make contact with the surface of the roller,will 
not force out glue which penetrates up to the side edges of the palettes, 
while ensuring effective glue transfer at the same time. 
It is preferred that the apparatus will include at least one nozzle by 
means of which glue is delivered to the roller, and that the grooves in 
the surface of the roller are held filled with glue with the aid of a 
scraper which coacts with the roller and which lies against the ridges 
extending between said grooves, so as to keep the ridges free from glue. 
The gluing roller is conveniently vertically oriented, and the glue nozzle 
is arranged at the upper end of the roller. The grooves provided in the 
gluing roller are preferably helical grooves which extend adjacent one 
another. Among other things, this provides a self-cleaning roller, since 
any labels which might stick to the roller will be "screwed" towards one 
end of the roller by the action of the glue scraper. 
According to one preferred embodiment, the rotational speed of the gluing 
roller and the working cycle of the gluing palettes is chosen so that the 
ridges between the roller grooves will coact with at least partially 
different parts of respective palettes after each preceding contact 
occasion. This rotational speed of the gluing roller and the pitch of the 
grooves are preferably so selected that the ridge-contacting surfaces of 
the palettes are shifted slightly downwards on the palette between 
mutually sequential contacts of said palette surfaces with said ridges.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
In the drawings, the reference numeral 1 identifies a vertically oriented, 
rotary gluing roller whose outer cylindrical surface is made of a hard 
material and provided with helical grooves 2, which are separated by 
intermediate ridges 3, conveniently flat ridges. The grooves are held 
filled with glue which is delivered to the grooves by means of an upper 
nozzle 4 and is distributed in the grooves and scraped from the ridges by 
means of a vertically oriented glue scraper 5 which resiliently abuts the 
ridges 3 separating the grooves 2 on the outer surface of the roller 1. 
This ensures that the ridges 3 will be kept free from glue. 
The reference numeral 6 identifies a carousel, which in the illustrated 
case is provided with three glue palettes 7, each of which is mounted for 
limited pivotal rotation about an associated pivot shaft 8. The whole of 
the carousel 6 rotates about a centre shaft 9. The gluing palettes may be 
made of a solid elastic material or of metal and coated with an elastic 
outer layer 10, see FIG. 1, having a flat label-contacting surface. 
The reference numeral 11 identifies a magazine for labels 17, while the 
reference numeral 12 identifies a rotary gripper provided with foam-rubber 
pads 13 having label-gripping devices. The reference numeral 14 identifies 
a carousel for bottles 15 which shall be labelled with labels taken from 
the magazine 11. The entire apparatus can be supported on a stand 16 which 
includes a gearbox having appropriate output shafts for the various 
rotational movements. 
When the aforedescribed arrangement is in operation, each gluing palette 7 
will pivot in relation to the gluing roller 1, in a conventional manner as 
the carousel 6 rotates, so that a layer of glue is applied to respective 
palettes 7 as they pass the roller. The palette then performs a 
corresponding movement as it passes the label magazine 11, wherein the 
first of the labels 17 in the magazine 11, in which the rear sides of the 
labels face forwards, fastens temporarily to the palette 7. When the label 
arrives at the gripping cylinder 12, as the carousel 6 rotates, the 
gripping devices in coaction with a foam-rubber pad 13 take the label from 
the palette 7 and, as the cylinder 12 rotates, press the glue-coated 
surface of the label against the appropriate bottle 15 on the bottle 
carousel 14, in a conventional manner. Transfer of the label from the 
palette 7 to the gripping cylinder 12 and pressing of the label onto the 
bottle 15 may also take place in a conventional manner. 
In accordance with the present invention, the aforedescribed apparatus is 
primarily characterized in that the gluing roller is provided with grooves 
2 and that the gluing palettes 7 have an elastic outer layer 10. As before 
mentioned, this enables the gluing palettes 7 to make contact with the 
gluing roller and to perform a rolling movement in relation thereto, 
without glue being forced out onto the edges of the palettes and while 
ensuring that glue will be effectively transferred as a result of the 
aforesaid partial penetration of the elastic outer layer on the gluing 
palettes into the glue-filled grooves on the roller. 
This greatly reduces the necessary manufacturing and adjustment tolerances, 
which, among other things, also reduces both manufacturing costs and 
operating costs and provides an apparatus which is much more reliable in 
operation and which ensures that a good result will be achieved. 
The grooves 2 on the gluing roller 1 will preferably have the form of 
helical grooves so that, among other things, a label or some other object 
which might fasten to the gluing roller will be automatically "screwed" 
downwards along the roller by the action of the scraper 5 as it moves 
along the ridges. The roller thus becomes self-cleaning, which is highly 
advantageous. Scrap and surplus glue can be collected at the bottom end of 
the roller. 
In order to avoid the ridges 3 located between the grooves 2 on the roller 
1 from becoming coated with glue, the gluing palettes 7 will preferably 
coact with essentially the same surface on the gluing roller on each 
rolling occasion. In order, however, to avoid uneven wear on the outer 
surface of the gluing palettes, it is preferred that the rolling surface 
is shifted slightly between sequential contact of a gluing palette with 
the roller. To this end, the rotational speed of the gluing roller is 
adapted in relation to the working cycle of the gluing palettes, so that 
the roller will not rotate through a complete revolution or through 
several complete revolutions between each palette rolling movement. 
However, it is necessary that the peripheral speeds of the roller and the 
palette essentially coincide. 
The rotational speed of the gluing roller and the pitch of the glue grooves 
are conveniently chosen so that the palette-contacting surfaces of the 
ridges will engage the palette successively at locations which are 
slightly displaced downwards in relation to preceding engaging locations. 
The distance through which the contact surfaces are displaced between each 
contact occasion may be on the order of some hundredths of a millimeter. 
The grooves may be relatively shallow, on the order of some tenths of a 
millimeter, depending on the desired thickness of the glue layer and on 
the quality of the glue used. The grooves may have a width of some 
millimeters, depending on the size of the label surface required to be 
coated with glue. By allowing the pitch of the grooves to vary along the 
gluing roller, the amount of glue can be varied between different parts of 
a label or between labels that are located at different heights. In 
addition to helical grooves, horizontal, circumferential grooves may also 
be used for instance, and the pitch between these grooves may be varied as 
desired. 
The novel features of the present invention can be applied with different 
types of labelling apparatus, for instance irrespective of the number of 
palettes used, the type of label magazine used, and the construction of 
the gripping devices mounted on the gripper. Furthermore, the palette 
carousel may be arranged to rotate in one direction or to pivot backwards 
and forwards between two positions.