The present invention concerns an improved picker designed to pick labels from the magazine of a labelling machine.

Prior art discloses units designed to pick labels from the magazines of labelling machines and consisting of starwheels peripherally equipped with paddle-like picking means. During work, each "paddle", whose contact surface is curved, moves past a gluing unit where it receives a thin film of glue, and then towards a label magazine. On reaching the magazine, it is rotated about a vertical axis and its rotational motion causes the contact surface of the paddle to roll on the label (without sliding) and (because of the glue on it) to pick up the label from the magazine.

According to the prior art, the full length of the label must stick to the curved contact surface of the paddle. In other words, the size of the label to be picked must not exceed the length of the curved contact surface of the paddle.

With conventional pickers of standard dimensions (that is, with starwheels approximately 400 mm in diameter, to limit the overall dimensions of the labelling machines where they are installed) label size may not usually exceed 180 to 220 mm.

At present, for labels larger than this, the diameter of the picker starwheel must be increased. Increasing the size of the picker, however, has practical and economic disadvantages. Fitting a picker with a larger diameter means increasing the overall dimensions of the labelling machine as a whole and production, transport and related costs inevitably rise accordingly.

In order to eliminate these disadvantages, a special label picker has been made which, while being of standard size, is capable of picking labels that are considerably longer than the curved contact surface of conventional starwheel paddles. This picker formed the subject matter of European patent application No. 94830108.0, filed on 15.03.1994, by the same applicant as that for the present invention patent.

In brief, the subject matter of the said patent application concerns a unit for picking labels from a magazine and consists of a starwheel peripherally equipped with a number of paddles designed to be smeared with glue as they move past a gluing unit and to then pick labels from a magazine. Each paddle is capable of partially rotating about its mounting shaft, the said shaft being equipped with a gear wheel that meshes with a sector gear capable of rotating partially in both directions around a pivot. Through its mounting shaft, the paddle is attached to a movable element that is mounted peripherally with respect to the starwheel and that has rigidly fixed to it a curved element, whose curvature is similar to that of the paddle and which is mounted in such a manner as to follow the rotational path of the starwheel. The said curved element is designed to receive the glue when it passes by the gluing unit and to support the part of each single label picked up that extends beyond the curved contact surface of the paddle itself. In addition, two runners which slide in two corresponding tracks are envisaged for the following purposes: (i) to enable the aforesaid movable element to move towards the outer side of the starwheel so as to allow the paddle to come into contact with the label and pick it from the magazine; and (ii) to enable the aforesaid sector gear to rotate the mounting shaft.

The picker disclosed in the aforesaid patent application effectively overcomes the disadvantages of previous pickers but itself presents certain disadvantages. The main disadvantage is due to the vibrations which the picker is subjected to during operation at high speeds and caused by the two shaped tracks: this is because high inertial forces are produced by the sudden movement of the paddle away from the magazine accomplished by a sharp change in the direction of the track in which the paddle itself runs. As a result, the productivity of the machine is limited because the vibrations prevent it from operating above a certain speed.

The principal aim of this invention is to eliminate the disadvantages of the prior art by providing an improved label picker which allows high speeds and, hence, high productivity, to be attained by considerably reducing the vibrations through the use of a single track.

Another aim of this invention is to provide an improved label picker that is simpler to construct than those disclosed by the prior art, thus allowing a reduction in production and running costs.

These and other aims are all achieved by the improved label picker forming the subject matter of the present invention, whose main technical characteristics are laid out in the claims below.

Further characteristics and advantages of the invention are apparent from the detailed description which follows, with reference to the accompanying drawings, which illustrate a preferred embodiment of the invention by way of example and in which:

• Figure 1 is a schematic plan view of a labelling machine equipped with the improved label picker disclosed by the present invention;
• Figures 2 and 3 are top and rear views, respectively, of the movable paddle modified according to the present invention;
• Figure 4 is a schematic plan view of the drive mechanism which moves the paddle near the label magazine.
• Figures 5 to 9 schematically illustrate the movable paddle during five consecutive stages in the process of picking up a label.

With reference to Fig. 1, the numeral 1 indicates a feed conveyor carrying bottles, jars or similar containers (not illustrated for convenience) to a starwheel 2 by way of an infeed starwheel 3. The starwheel is the structure on which labels are applied to the bottles or other containers by a labelling drum 4. After being labelled, the containers are placed on a conveyor 6 by an outfeed starwheel 5.

With reference to all the accompanying drawings, the numeral 7 indicates the label picker disclosed by the present invention, the numeral 8 indicates a gluing unit and 9 a label magazine.

The parts of a labelling machine just listed, with the exception of the improved label picker made according to the present invention, are known to the trade and are not therefore described in any further detail.

The label picking unit 7 (the labels are indicated with the numeral 10) consists of a starwheel 11 peripherally equipped with paddles 12 each of which has a curved contact surface 13 designed to pick up the labels 10 from the magazine 9 one by one after moving past the gluing unit 8.

Each paddle 12 can rotate partially about its mounting shaft 18 to which a gear 19 is keyed, the said gear being driven by a sector gear 22 which is capable of rotating partially in both directions about a pin 23 attached to the starwheel 11.

The partial rotation of the sector gear 22 is achieved by a sliding runner 24 mounted by the sector gear 22 itself and designed to run in a substantially circular track 25 made in the fixed base under the starwheel 11.

As shown in Fig. 4, near the magazine 9, the curvature of track 25 changes its substantially circular form and the track 25 runs towards the inner side of the fixed base (see top part of Fig. 4). This change in the direction of the track causes runner 24 in that section of the track to run in an approximately radial centripetal direction (with respect to the centre of the starwheel 11) and this causes a partial rotation of sector gear 22 around the pin 23. As a result, the paddle 12 also rotates about its shaft.

In addition to the paddle 12, the starwheel 11 also has rigidly attached to it a curved element 28, with a contact surface 29 having a curvature similar to that of the surface 13 of the paddle 12, and mounted on the circular path of the paddle 12 which is mounted in such a manner as to follow the rotational path of the starwheel 11.

The said curved element 28 is designed to receive the glue when it passes by the gluing unit 8 and to support on its surface 29 the part of each single label 10 picked up that extends beyond the curved contact surface 13 of the paddle 12. This function is illustrated in Figs. 7, 8 and 9.

As shown in Figs. 8 and 9, the contact surface 13 of the paddle 12 is appropriately shaped, so as to enable the paddle 12 to come into contact with the label 10 inside the magazine 9 (rolling on the label without sliding on it thanks to the rotation of the sector gear 22) and then to move away without interfering with the magazine 9.

The innovation consists in the fact that the front end 30 (with respect to the direction of rotation of starwheel 11) of the curved contact surface 13 of the paddle 12 is positioned in such a way as to be within an angle α of between 6° and 23° measured (in a direction opposite the direction of rotation of the starwheel 11) starting from a reference line R joining, and perpendicular to, the axis of rotation A of the starwheel 11 and the axis of rotation B of the mounting shaft 18.

This condition is illustrated in Fig. 9.

Fig. 2, in particular, shows the configuration of the paddle 12 according to the present invention (continuous line) compared to the configuration of a traditional paddle (dashed line).

The aims of the invenion are achieved by the fact that the contact surface 13 of the paddle 12 is further back with respect to the direction of rotation of the starwheel 11 by an angle α falling within the aforementioned limits (6° < α < 23°).