EP3351482B1

EP3351482B1 - Plate for labelling machine and carousel labelling machine comprising a plurality of plates

Info

Publication number: EP3351482B1
Application number: EP17209111.8A
Authority: EP
Inventors: Giovanni Saccardi
Original assignee: Kosme SRL
Current assignee: Kosme SRL
Priority date: 2017-01-24
Filing date: 2017-12-20
Publication date: 2019-03-13
Anticipated expiration: 2037-12-20
Also published as: EP3351482A1; ES2727301T3; IT201700007577A1

Description

This invention relates to the field of container labelling. In particular, it relates to a plate according to the preamble of claim 1 for a labelling machine with a carrousel, as well as to a labelling machine comprising a plurality of plates.
The labelling machine according to this invention is included in the type of labelling machines comprising a plurality of plates mounted on a rotary carrousel. Machines of this type are used for labelling containers, for example bottles, enabling one or more labels to be stuck in the desired position on the lateral surface of those containers.
However, some containers are asymmetrical relative to their axis of extension, therefore, correct positioning of each label on a particular zone of the outer surface of such containers could be very complicated. In other cases the sequential positioning of multiple labels on the same container is required. Correct centring of these labels relative to one another may be complicated.
In order to overcome such problems, in the prior art, at the time of making the containers, a recess is made in the bottom of them. That recess is eccentric relative to the axis of extension of the container. The purpose of the recess is to enable correct orientation of the container thanks to recognition of the position of the self-same recess, by means of suitable devices, in order to be able to subsequently apply the labels on the container in the correct position.
One example of a labelling machine that uses said recess for container orientation is described for example in the publication of international patent application No. WO 2015/008304 A1 , which also includes comments about several prior art machines that came before it. This document discloses a plate in accordance with the preamble of claim 1.
However, in particular in the case of deformable or light containers (for example, plastic bottles), recognition of the correct position of the container thanks to a recess in the bottom may be problematic and sometimes erroneous. In fact, it may be the case that a tooth intended to be inserted in the recess in order to allow recognition of the position does not successfully remain housed in the recess due to deformations or oscillations of the container. In practice, the tooth may jump out of the recess in an unexpected or uncontrolled way, with consequent loss of position control.
Another example of a labelling machine that uses said recess for container orientation is described in German patent application No. DE 10 2007 030 917 A1 . A groove or notch is molded in the container by blow molding at a transition between a container body and a container base. Said groove or notch is used as a feature to be detected by an opto-electrical detection system when the container is rotated and moved on a container support in a transfer direction. An opto-electrical detection system is more complex and more expensive than a system using a tooth intended to be inserted in the recess.
In this context, the technical purpose which forms the basis of this invention is to provide a labelling machine with a carrousel, which at least partly overcomes these disadvantages.
The technical purpose is substantially achieved by a plate for a labelling machine with a carrousel according to the independent claim 1 and by a labelling machine with a carrousel according to claim 9. Particular embodiments of this invention are defined in the corresponding dependent claims.
According to one aspect of this invention, the position of a container to be labelled is recognised using at least three hooking teeth, which are intended for insertion in respective recesses made in the bottom of the container. The hooking teeth are angularly spaced from one another along an arc of a circle that is centred on an axis of rotation relative to which the container has a rotating movement relative to the hooking teeth. Therefore, during use of the labelling machine the container to be labelled rotates relative to the hooking teeth until the hooking teeth are located at the recesses and are inserted in them, thereby hooking the container.
The use of a plurality of hooking teeth (in particular, three or more teeth) is useful because it creates a more stable connection between the container and the hooking teeth even if the container is deformable. In fact, the interference of parts between the container bottom and the position recognition system in multiple regions along an arc of the bottom of the container rather than in a single region significantly reduces the possibility that the bottom of the container may accidentally come unhooked from the recognition system.
In a specific embodiment, the arc of a circle on which the hooking teeth are arranged has an angular amplitude that is greater than or equal to 180° That is useful for having an even more stable connection thanks to hooking points that are distributed on a large part of the circumference of the bottom of the container.
According to another aspect of this invention, relative to the axis of rotation the hooking teeth are in positions that are angularly spaced from one another, in such a way that, overall, they do not have rotary symmetry. Basically, when all of the hooking teeth are rotated about the axis of rotation together, the positions that they initially occupied are all occupied again only after a 360° rotation. Therefore, if the respective recesses in the bottom of the container are distributed in the same way without rotary symmetry and with corresponding angular distances, there is only one mutual angular position of the container in which the hooking teeth are simultaneously inserted in the respective recesses. This is useful for ensuring that the angular position of the container can be univocally identified.
In one embodiment, the plate comprises a disk-shaped support for in use supporting a container to be labelled, the disk-shaped support comprising two parts that are concentric and axially movable relative to one another. A first part comprises an annular first resting surface, a second part is surrounded by the first part and comprises a substantially frustoconical second resting surface. That is useful for adapting the disk-shaped support surface for contact with the bottom of the container, so that the container does not slip relative to the disk-shaped support when the latter is rotating. If necessary, this aspect relating to the two-part disk-shaped support could be protected separately from the use of a plurality of hooking teeth.
In one embodiment, the plate comprises an outer body relative to which a disk-shaped support for the container is rotatable about the axis of rotation and is slidable along an axial line, parallel to the axis of rotation. The disk-shaped support has a bottom surface that, in a position in which the disk-shaped support is axially shifted towards the bottom of the outer body, is intended to make contact with the bottom of the outer body for creating a friction force that makes the outer body and the disk-shaped support rotate together with one another. If necessary, this aspect too could be protected separately from the use of a plurality of hooking teeth.
Finally, it is also disclosed a container comprising a body with a central axis and a bottom, wherein the outer face of the bottom comprises at least three recesses that are located in an annular region that is centred on the central axis. The at least tree recesses are in positions that are angularly spaced from one another in such a way that overall the recesses on the outer face of the bottom do not have rotary symmetry relative to the central axis. That container is useful because it is suitable for being labelled by a labelling machine according to this invention.
Further features and the advantages of this invention will be more apparent in the detailed description of a preferred, non-limiting embodiment of a plate for a labelling machine with a carrousel, illustrated in the accompanying drawings, in which:

Figure 1 is a perspective view of a plate according to this invention;
Figure 2 is a top view of the plate of Figure 1;
Figure 3 is a top view of the plate of Figure 1, in which some parts are not shown;
Figure 4 is an exploded perspective view of the plate of Figure 1;
Figure 5 is a side view of the plate of Figure 1, in section according to the line V-V in Figure 2;
Figure 6 is a perspective view of the plate of Figure 1, in section according to line VI-VI in Figure 2;
Figure 7 is a perspective view of a component of the plate of Figure 1;
Figure 8 is a perspective bottom view of the component of Figure 7;
Figure 9 is a sectional view of the component of Figure 7;
Figure 10 is an exploded perspective view of the component of Figure 7;
Figure 11 is a side view of a detail of the plate of Figure 1, in section according to line XI-XI in Figure 2, in a first condition;
Figure 12 is a side view of a detail of the plate of Figure 1, in section according to line XI-XI in Figure 2, in a second condition;
Figure 13 is a side view of a detail of the plate of Figure 1, in section according to line XI-XI in Figure 2, in a third condition;
Figure 14 is a side view of a detail of the plate of Figure 1, in section according to line XI-XI in Figure 2, in a fourth condition;
Figure 15 is a schematic top view of a part of a labelling machine with a carrousel comprising a plate of Figure 1, the machine being shown without the labelling devices;
Figure 16 is a side view of a container which can be labelled by the labelling machine of Figure 15;
Figure 17 is a bottom view of the container of Figure 16;
Figure 18 is a sectional view, corresponding to Figure 11, of a first operating step of the plate of Figure 1;
Figure 19 is a sectional view, corresponding to Figure 12, of a second operating step of the plate of Figure 1;
Figure 20 is a sectional view, corresponding to Figure 13, of a third operating step of the plate of Figure 1;
Figure 21 is a sectional view, corresponding to Figure 14, of a fourth operating step of the plate of Figure 1.

With reference to the above-mentioned figures, the reference numeral 1 denotes a plate according to this invention in its entirety. That plate 1 is intended for a labelling machine with a carrousel, such as the one partly illustrated in Figure 15 and labelled with the reference numeral10.
Similarly to prior art labelling machines, the labelling machine 10 comprises a supporting structure, a carrousel 11 and a plurality of plates 1 (only one of which is shown in Figure 15) mounted on the carrousel 11. The carrousel 11 is rotatably mounted on the supporting structure about an axis of rotation of the carrousel 11 and in use is rotatable driven by a main motor connected to the carrousel 11.
The labelling machine 10 also comprises at least one conveying lane that is substantially adjacent to the carrousel 11 for in use conveying the containers to be labelled towards the carrousel 11, at least one infeed pickup starwheel that is positioned substantially between the carrousel 11 and the conveying lane for in use picking up the containers from the conveying lane and positioning them on one of the plates 1, and at least one labelling device that is positioned or positionable adjacent to the carrousel 11 for in use sticking one or more labels on each container to be labelled.
The labelling machine 10 further comprises at least one outfeed pickup starwheel that is adjacent to the carrousel 11, for in use picking up the labelled containers from the plates 1 and positioning them on an outfeed path that is positioned substantially adjacent to the carrousel 11 and is defined by the conveying lane.
It should be noticed that the conveying lane, the outfeed path, the infeed pickup starwheel and the outfeed pickup starwheel are in themselves known and, therefore, are not illustrated herein and are not described in detail.
The labelling machine 10 also comprises an upper section mounted on the supporting structure, which is positioned substantially above the carrousel 11 and is rotatable relative to the supporting structure about the axis of rotation of the carrousel 11, substantially synchronised with the carrousel 11. Mounted on said upper section there are thrust devices which in use are positioned or positionable above each container to be labelled. Those thrust devices may be of the known type, for example bell-shaped elements operated by elastic means, by jacks or by hydraulic or pneumatic cylinders, and in use rotate together with the upper section.
The aspects relating to the upper section, to the thrust devices and to other general operating aspects of the labelling machine 10 may be considered substantially belonging to the prior art and, in particular, reference should be made to the above-mentioned publication of international patent application No. WO 2015/008304 A1 .
The labelling machine 10 differs from prior art labelling machines mainly as regards the individual plate 1 and in particular as regards a system for controlling or managing the angular position of the container to be labelled on the plate 1.
An example of a container that can be labelled by the labelling machine 10 is shown in Figures 16 to 18, in which it is labelled with the reference numeral 9. In Figures 19 to 21 only a portion of the bottom 91 of the container 9 is shown. The container 9 is, for example, a bottle, of the type used to hold distilled water or other products. In particular, the container 9 is made of plastic material and has a volume of five litres. However, it shall be understood that this invention is not in any way limited to this type of container.
The container 9 has a substantially cylindrical body and has an outer bottom face 92, shown in an enlarged view in Figure 17. In the embodiment illustrated, the outer bottom face 92 has a central region 93 that is sunken in a cone shape and an annular region 94 for resting on a surface. A plurality of hollows 95 are made in the annular region 94. The hollows are angularly spaced equidistant from one another and may have a function of reinforcing the bottom 91 of the container 9. Some of those hollows 95 have a portion widened relative to the rest of the hollow 95.
As shown in Figure 17, thanks to said widened portions of the hollows 95 in the outer face of the bottom 92 of the container 9, therefore, recesses (or grooves) are formed, there being four in the embodiment illustrated, which are labelled 961, 962, 963, 964. Those recesses are located in an annular region that is centred on the central axis 90 of the container 9. Therefore, they are equidistant from the central axis 90, and they are in positions that are angularly spaced from one another in such a way that overall they do not have rotary symmetry relative to the central axis 90. That means that, if one imagines rotating the view of Figure 17 about the central axis 90, it is only after a 360° rotation that the recesses occupy all of the angular positions occupied in the view of Figure 17.
In contrast, if the four recesses were angularly spaced at 90° from one another, they would have rotary symmetry relative to the central axis 90 because, overall, they would occupy the same angular positions even after a rotation of 90°, of 180°and of 270°.
In other words, since the recesses in the bottom face 92 do not have rotary symmetry, each angular position of the bottom face 92 relative to the central axis 90 can be distinguished from a reference angular position, for example, the position shown in Figure 17.
In particular, in the illustrated container the absence of rotary symmetry is obtained by angularly spacing only three recesses 961, 962, 963 at 90°from each other, whilst the fourth recess 964 is angularly spaced at 45°from the third recess 963.
In alternative comparative examples, there could be a different number of those recesses (for example three, or more than four) and they could even be made in the absence of the hollows 95 or interposed between the latter instead of being at them.
For example, using only three recesses, the absence of rotary symmetry could be obtained with only the recesses 961, 962, 963 that are at 90° to one another, therefore, without the fourth recess 964, or by not having any one of the recesses 961, 962, 963, or in any case by positioning the three recesses in such a way that they are not all 120°f rom each other. The same principles also apply with a larger number of recesses.
Returning to the individual plate 1, it comprises an outer body 2 and, inside this, a disk-shaped support 3 that in use is intended to support the container 9 to be labelled. The disk-shaped support 3 is associable with the bottom 92 of the container and is rotatable about an axis of rotation 30 that is a central axis of the disk-shaped support 3. In particular, when the container 9 is on the disk-shaped support 3, the central axis 90 of the container 9 basically corresponds to the axis of rotation 30 of the disk-shaped support 3. Moreover, specifically, the disk-shaped support 3 is rotatable relative to the outer body 2 about the axis of rotation 30.
Furthermore, the outer body 2 is mounted on the carrousel 11 in such a way that it is rotatable about the same axis of rotation 30, so that the entire plate 1 can rotate relative to the carrousel 11 about the central axis 30 of the disk-shaped support 3.
Specifically, the outer body 2 comprises a top ring 21, a base 23 and a bottom 25. Those parts are fixed to each other by means of screws. Moreover, a containment half-ring 27 is fixed on the top ring 21. The plate 1 can be completely disassembled.
The top face of the disk-shaped support 3 constitutes a resting surface for the bottom 92 of the container 9. Moreover, the disk-shaped support 3 has the function of making the container 9 rotate about its central axis 90. For this purpose, the top face of the disk-shaped support 3 preferably has knurled surfaces in order to increase the friction with the container 9 so as to drag it in a rotating motion.
In the embodiment illustrated, the disk-shaped support 3 comprises two parts that are concentric and axially movable (that is to say, parallel to the axis of rotation 30) relative to one another: a first part 31 comprises an annular first resting surface 311, a second part 32 is surrounded by the first part 31 and comprises a substantially frustoconical second resting surface 321. Basically, the first resting surface 311 is flat and intended to receive the annular region 94 of the bottom 92 of the container 9, whilst the second resting surface 321 is intended to receive the conical central region 93 of the bottom 92 of the container 9, which it is at least partly shaped to match. The first resting surface 311 and the second resting surface 321 are both knurled. As shown in the figures, in practice the first part 31 is an outer ring that is positioned around the inner second part 32 and is slidable relative to the latter. The first part 31 comprises radial projections 312 that project radially inwards and are slidably inserted in corresponding guiding hollows or tracks 322 made in the second part 32. The interaction between the radial projections 312 and the guiding tracks 322 only allows an axial sliding movement between the parts 31, 32 and prevents them from rotating relative to one another.
Moreover, elastic means axially push the first part 31 upwards, away from the second part 32. Those elastic means are, in particular, springs 33 which are positioned in the guiding tracks 322, each between the bottom of a guiding track 322 and the respective radial projection 312. A locking ring or locking plate 34, fixed with screws to the top of the second part 32, prevents the first part 31 from coming off the second part 32.
A home condition is shown in Figure 9, in which the first resting surface 311 is substantially level with the top of the second resting surface 321. Basically, the frustoconical surface does not project from the first resting surface 311. When a container 9 is resting on the disk-shaped support 3, its annular region 94 is on the first resting surface 311.
When the thrust devices of the upper section of the labelling machine 10 apply a downward force on the container 9, the first part 31 and the container 9 itself slide axially, causing the second resting surface 321 to project until it makes contact with the conical central region 93 of the container 9. Thanks to this, the contact surface and the friction between the container 9 and the disk-shaped support 3 are adaptable and adjustable by suitably controlling the thrust devices. In practice, thanks to the two parts 31, 32 which are axially movable relative to each other, the overall resting surface provided by the disk-shaped support 3 adapts to the bottom 92 of the container 9, enabling the contact surface to be maximised.
Even the bottom surface 323 of the disk-shaped support 3, that is to say, the opposite face to the top face on which the container 9 rests, is knurled. In particular, that bottom surface 323 is an annular region that belongs to the second part 32. In an operating step that will be described below, the bottom surface 323 makes contact with a rubber ring 29 that is fixed to the bottom 25 of the outer body 2.
The disk-shaped support 3 (in particular, its second part 32) is fixed to a respective support 36 that is mounted at the end of a shaft 37 that is coaxial with the axis of rotation 30 and extends below the plate 1. A pulley 38 is fixed to the opposite end of the shaft 37.
The support 36 is mounted on the shaft 37 in such a way that the support 36 is capable of axial sliding along the shaft 37, but cannot rotate relative to it. Therefore, the disk-shaped support 3 and the pulley 38 are made to rotate together, by means of the shaft 37 and the support 36, about the axis of rotation 30. Moreover, the entire disk-shaped support 3 is axially slidable relative to the outer body 2. A spring 39, positioned between the support 36 and the bottom 25 of the outer body 2, pushes the disk-shaped support 3 axially upwards. The shifting of the disk-shaped support 3 in an upward direction is limited at the top by a stop element 28 fixed to the outer body 2. The plate 1 also comprises four hooking teeth 41, 42, 43, 44 which are arranged on a teeth-holding member 40, in positions spaced along an arc of a circle that is centred on the axis of rotation 30. In practice, the hooking teeth 41, 42, 43, 44 are positioned one after another relative to a path along said arc of a circle.
In particular, said four hooking teeth 41, 42, 43, 44 are positioned outside the disk-shaped support 3: the arc of a circle on which said hooking teeth are positioned is around the periphery of the disk-shaped support 3 and, specifically, the hooking teeth are located around the first part 31 of the disk-shaped support 3.
As shown in the figures, the four hooking teeth 41, 42, 43, 44 extend upwards from the teeth-holding member 40, that is to say, towards the container 9 on the plate 1. Each hooking tooth 41, 42, 43, 44 is, in use, intended to be inserted in a respective recess 961, 962, 963, 964 in the bottom 92 of the container 9 that is supported by the disk-shaped support 3. For example, each hooking tooth 41, 42, 43, 44 is substantially shaped to match the shape of the respective recess 961, 962, 963, 964 in the bottom of the container 9 and its distance from the axis of rotation 30 is the same as the distance of the recess from the central axis 90 of the container 9. Moreover, each hooking tooth has dimensions larger than the hollows 95, therefore, in use, each hooking tooth can be inserted in the respective recess but not in the other hollows 95.
The teeth-holding member 40 is movable relative to the disk-shaped support 3 along an axial line (that is to say, along a line parallel to the axis of rotation 30), therefore, the four hooking teeth 41, 42, 43, 44 are movable relative to the disk-shaped support 3 between an engaged position and a disengaged position. In the engaged position, shown in Figures 13, 14, 20 and 21, the hooking teeth project upwards relative to the first resting surface 311 and, in use, they are inserted in the respective recesses 961, 962, 963, 964 of the container 9, thereby hooking the container 9 to the teeth-holding member 40. In the disengaged position, shown in Figures 11, 12, 18 and 19, the hooking teeth are level with the first resting surface 311 and, in use, they are not associated with the respective recesses 961, 962, 963, 964.
Moreover, the disk-shaped support 3 is angularly shiftable relative to the teeth-holding member 40. In particular, the disk-shaped support 3 is rotatable about the axis of rotation 30 whilst the teeth-holding member 40 is stationary. Therefore, in use, the container 9 supported by the disk-shaped support 3 is angularly shiftable relative to the hooking teeth 41, 42, 43, 44, for positioning the hooking teeth at the respective recesses 961, 962, 963, 964.
The four hooking teeth 41, 42, 43, 44 are mounted (or if necessary made) on the teeth-holding member 40 in positions that are angularly spaced from one another in such a way that overall they do not have rotary symmetry relative to the axis of rotation 30, similarly to what was described above concerning the recesses 961, 962, 963, 964 in the bottom 92 of the container 9.
The angular distances between the hooking teeth 41, 42, 43, 44 correspond to the angular distances between the recesses 961, 962, 963, 964 in the bottom of the container 9.
Therefore, in the embodiment illustrated, three hooking teeth 41, 42, 43 are angularly spaced at 90°from each other (that is to say, the angular distance A1 between the hooking teeth 41, 42 and the angular distance A2 between the hooking teeth 42, 43 are both 90°), whilst the fourth hooking tooth 44 is at an angular distance A3 of 45° from the third hoo king tooth 43. Advantageously, the arc of a circle on which the hooking teeth are arranged has an angular amplitude A0 that is greater than or equal to 180° and, in particular, in the embodiment illustrated that angular amplitude A0 is 225° Since the hooking teeth 41, 42, 43, 44 move rigidly with the teeth-holding member 40 along the axial line 30 and they are not movable independently of one another, they are only insertable in the recesses simultaneously, that is to say, when each hooking tooth is located below a respective recess and at it. In fact, if even one of the hooking teeth is located at the annular region 94 and not at a recess, the movement of the hooking teeth towards the engaged position is prevented and, therefore, they remain in the disengaged position. In contrast, when all of the hooking teeth are at the recesses, they can pass from the disengaged position to the engaged position.
Since the hooking teeth are in angular positions that overall do not have rotary symmetry, there is only one mutual angular position of the container 9 relative to the hooking teeth in which the latter are simultaneously insertable in the respective recesses and, therefore, can go into the engaged position. In practice, in use the engaged position is only possible when, at the same moment, the first hooking tooth 41 is at the first recess 961, the second hooking tooth 42 is at the second recess 962, the third hooking tooth 43 is at the third recess 963 and the fourth hooking tooth 44 is at the fourth recess 964.
In the embodiment illustrated, the teeth-holding member 40 is mounted on the outer body 2 in such a way that it is slidable along the axial line 30. In particular, the teeth-holding member 40 comprises a top ring on which the hooking teeth and guiding columns 46 are fixed. The guiding columns 46 extend axially below the top ring to which they are fixed. The guiding columns 46 are slidably inserted in corresponding holes 236 made in the base 23 of the outer body 2. Therefore, the teeth-holding member 40 can translate axially relative to the outer body 2 but it cannot rotate relative to the latter.
The plate 1 also comprises elastic elements which are designed to push the teeth-holding member 40 towards the engaged position, that is to say, axially upwards. Specifically, those elastic elements are springs 47 which are interposed between the top ring of the teeth-holding member 40 and the base 23 of the outer body 2.
A top ring 21 of the outer body 2 forms an upper contact element against which the teeth-holding member 40 makes contact in the upward movement, thereby preventing removal of the teeth-holding member 40 from the plate 1. An operating method of the plate 1 is described below.
A container 9 is positioned on the plate 1 in the known ways. In the initial condition shown in Figures 5, 6, 11 and 18, the disk-shaped support 3 and the teeth-holding member 40 are both held in position at the maximum height by the respective springs 39, 47. The top faces of the hooking teeth 41, 42, 43, 44 and the first resting surface 311 of the disk-shaped support 3 are on the same level ("level zero" L0) of the operating plane. The second resting surface 321 is below that level zero. The annular region 94 of the bottom 92 of the container 9 rests on the first resting surface 311 and the hooking teeth, not projecting from level zero, cannot engage in the recesses. In this initial step, the carrousel 11 rotates about its axis but the outer body 2 and the disk-shaped support 3 are not rotating about the axis of rotation 30. After the container 1 has been positioned on the plate, a thrust device located above it presses the container 9 downwards, for example acting on the cap 97 of the container 9. Specifically, the thrust device presses the container 9 downwards with an 11 mm stroke. Therefore, as it is pushed by the container 9, the disk-shaped support 3 is lowered and its spring 39 is compressed. Moreover, the annular first part 31 of the disk-shaped support 3, on which the downward thrust applied by the container 9 acts immediately, is lowered more than the central second part 32. Consequently, the second resting surface 321 projects relative to the first resting surface 311 and makes contact with the sunken central region 93 of the bottom 92 of the container 9, despite also being lowered relative to level zero.
The hooking teeth 41, 42, 43, 43 are also pushed downwards by the annular region 94 of the bottom 92 of the container 9, except the rare case in which they are already at the respective recesses. Therefore, the teeth-holding member 40 is lowered, compressing the springs 47. The top faces of the hooking teeth 41, 42, 43, 44 and the first resting surface 311 of the disk-shaped support 3 are on the same level. The condition described here is shown in Figures 12 and 19.
Again in this step, the carrousel 11 continues rotating about its axis, whilst the outer body 2 and the disk-shaped support 3 are not rotating about the axis of rotation 30. At some point of the rotation of the carrousel 11, the pulley 38 encounters an arc-shaped contact element 18 that is fixed to the supporting structure of the labelling machine 10 and that does not rotate with the carrousel 11. That starts the centring step for the container 9.
With the further rotation of the carrousel 11, the pulley 38 rolls on the arc-shaped contact element 18 and causes the disk-shaped support 3 to rotate. Thanks to the friction between the knurled surfaces 311, 321 and the bottom of the container 9, the container 9 is made to rotate about the axis of rotation 30 (which coincides with its own axis 90).
The friction between the bottom of the container 9 and the top faces of the hooking teeth is very minor and is not sufficient to transmit a rotating movement to the teeth-holding member 40 and to the outer body 2, which therefore do not rotate about the axis of rotation 30.
Therefore, during the rotation of the container 9, the bottom 92 slides on the hooking teeth, which are held in the lowered position (that is to say, in the disengaged position) by the pressing force applied by the annular region 94, the container 9 being held down by the thrust device located above it. At some point of the rotation of the container 9, at most after having completed just less than a rotation of 360° the recesses 961 , 962, 963, 964 are located precisely at the hooking teeth 41, 42, 43, 44. Since in that configuration there is no longer any force pressing the hooking teeth downwards, the teeth-holding member 40 is thrust upwards by the springs 47 and the hooking teeth enter the respective recesses, moving into the engaged position. This is shown in Figures 13 and 20.
In this condition, the bottom 92 of the container 9 is hooked by the hooking teeth 41, 42, 43, 44, which by means of the teeth-holding member 40 make it rotate together with the outer body 2. In other words, relative to the outer body 2 of the plate 1 the container 9 is locked in a desired position, which is linked to the positioning of the hooking teeth 41, 42, 43, 44 relative to the outer body 2 and is univocally defined thanks to the positioning without rotary symmetry of the hooking teeth and of the corresponding recesses.
The labelling machine 10 is made in such a way that the friction between the pulley 38 and the arc-shaped contact element 18 is less than the friction between the disk-shaped support 3 and the container 9. Therefore, when the hooking teeth are in the engaged position the disk-shaped support 3 is held stationary by the friction with the container 9 and the pulley 38, being unable to roll any more, slides along the arc-shaped contact element 18 until it reaches the end of the latter.
Once the movement beyond the arc-shaped contact element 18 is also complete, the thrust device further presses the container 9 downwards. With the hooking teeth in the engaged position, the teeth-holding member 40 and the disk-shaped support 3 are also pushed downwards, until the bottom surface 323 of the disk-shaped support 3 makes contact with the rubber ring 29 fixed to the outer body 2, as shown in Figures 14 and 21.
At this point, thanks to the friction between the disk-shaped support 3 and the rubber ring 29, the disk-shaped support 3 also rotates together with the outer body 2. The container 9 remains in the desired position relative to the outer body 2. Then the step of labelling the container 9 can begin, during which the outer body 2 (and with it the disk-shaped support 3 and the container 9), by means of known systems, for example, sector cam and pinion systems, is synchronised in a predetermined position and a label is applied on the container 9 in the correct position. These aspects in themselves are known and are not described in further detail.
The invention described above with reference to a specific embodiment may be modified and adapted in many ways, without thereby departing from the scope of the appended claims.
For example, there could be only three hooking teeth instead of four, which are also in positions that are angularly spaced from one another and that overall do not have rotary symmetry. In this case, the container could have only three recesses, corresponding to the hooking teeth, or it could have four or more recesses provided that there is only one possible angular position for hooking with the three hooking teeth.
With regard to this, it should be noticed that, with a container 9 that has four recesses 961, 962, 963, 964 as described above, the labelling machine 10 could operate in a similar way even if, for example, the third hooking tooth 43 were not present. In fact, there would still be only one mutual angular position in which all of the hooking teeth can simultaneously enter the recesses in order to hook the container.
Therefore, in general, the bottom of the container may have a number of recesses that is greater than the number of hooking teeth of the plate, provided that the requirement of having only one mutual angular position for hooking is complied with.
In the embodiment illustrated, the hooking teeth 41, 42, 43, 44 are identical to each other, as are the recesses in the bottom of the bottle. However, in alternative embodiments the hooking teeth could be different from each other, provided that the respective recesses were shaped for receiving them. If necessary, the hooking teeth (and, in the corresponding way, the respective recesses) might not be equidistant from the axis of rotation of the plate.
In alternative embodiments, the teeth-holding member might not be able to translate along an axial line and in this case the achievement of the hooking position would correspond to the possibility of pushing the container and the disk-shaped support further downwards.
In alternative embodiments, the teeth-holding member might not rotate together with the outer body. For example, during the centring step the disk-shaped support and the container might remain stationary relative to the outer body, whilst the teeth-holding member might rotate relative to the disk-shaped support until it reaches the mutual angular position corresponding to hooking. In that configuration, the angular shifting of the disk-shaped support relative to the teeth-holding member may be performed by rotating the teeth-holding member relative to the outer body, rather than rotating the disk-shaped support.
In alternative embodiments, rotation of the disk-shaped support and of the container may be performed in a different way to the system with pulley and arc-shaped contact element, for example, there could be a dedicated motor. This invention may be useful particularly for labelling "yielding" containers, for which the system with a single notch has proved quite unreliable. In any case, thanks to more stable hooking of the container, this invention is also useful for containers that are not yielding.
It should also be noticed that this invention is relatively easy to produce and that even the cost linked to implementing the invention is not very high.
All details may be substituted with other technically equivalent elements and the materials used, as well as the shapes and dimensions of the various components, may vary according to requirements.

Claims

A plate (1) for a labelling machine (10) with a carrousel, comprising:
- a disk-shaped support (3) for in use supporting a container (9) to be labelled, the disk-shaped support (3) being associable with a bottom (92) of the container (9) and being rotatable about an axis of rotation (30) that is a central axis of the disk-shaped support (3); characterized by

- at least three hooking teeth (41, 42, 43, 44) which are arranged on a teeth-holding member (40) in positions spaced along an arc of a circle that is centred on the axis of rotation (30), each hooking tooth (41, 42, 43, 44) being intended in use for being inserted in a respective recess (961, 962, 963, 964) made in the bottom (92) of the container (9) supported by the disk-shaped support (3);
the teeth-holding member (40) being movable relative to the disk-shaped support (3) along an axial line parallel to the axis of rotation (30), so that the at least three hooking teeth (41, 42, 43, 44) are movable relative to the disk-shaped support (3) between an engaged position, in which in use the at least three hooking teeth (41, 42, 43, 44) are inserted in said respective recesses (961, 962, 963, 964) of the container (9) thereby hooking the container (9), and a disengaged position, in which in use the at least three hooking teeth (41, 42, 43, 44) are not associated with said respective recesses (961, 962, 963, 964) of the container (9);
the disk-shaped support (3) being angularly shiftable relative to the teeth-holding member (40), whereby in use the container (9) supported by the disc-shaped support (3) is angularly shiftable relative to the at least three hooking teeth (41, 42, 43, 44) for positioning the at least three hooking teeth (41, 42, 43, 44) at said respective recesses (961, 962, 963, 964) of the container (9);
the at least three hooking teeth (41, 42, 43, 44) being in positions that are angularly spaced from one another and that overall do not have rotary symmetry relative to the axis of rotation (30), whereby in use, with respective recesses (961, 962, 963, 964) in the bottom (92) of the container (9) that are spaced at corresponding angular distances from each other, the at least three hooking teeth (41, 42, 43, 44) are simultaneously insertable in the respective recesses (961, 962, 963, 964) for a single mutual angular position of the container (9) relative to the at least three hooking teeth (41, 42, 43, 44).
The plate (1) according to claim 1, wherein the at least three hooking teeth (41, 42, 43, 44) are positioned outside the disk-shaped support (3), said arc of a circle being around the periphery of the disk-shaped support (3).
The plate (1) according to claim 1 or 2, comprising an outer body (2) relative to which the disk-shaped support (3) is rotatable about the axis of rotation (30), the teeth-holding member (40) being mounted on the outer body (2) in such a way that it is slidable along the axial line (30).
The plate (1) according to any of claims 1 to 3, comprising elastic elements (47) designed to push the teeth-holding member (40) relative to the disk-shaped support (3) towards the engaged position.
The plate (1) according to any of claims 1 to 4, comprising four of said hooking teeth (41, 42, 43, 44), which are mounted on the teeth-holding member (40) in positions spaced along an arc of a circle.
The plate (1) according to any of claims 1 to 5, wherein said arc of a circle has an angular amplitude (A0) greater than or equal to 180°.
The plate (1) according to any of claims 1 to 6, wherein the disk-shaped support (3) comprises two parts (31, 32) that are concentric and axially movable relative to one another, a first part (31) comprising an annular first resting surface (311), a second part (32) being surrounded by the first part (31) and comprising a substantially frustoconical second resting surface (321).
The plate (1) according to any of claims 1 to 7, comprising an outer body (2) relative to which the disk-shaped support (3) is rotatable about the axis of rotation (30) and is slidable along the axial line (30), the disk-shaped support (3) comprising a bottom surface (323) that, in a position in which the disk-shaped support (3) is axially shifted towards a bottom (25) of the outer body (2) of the plate (1), is intended to make contact with the bottom (25) of the outer body for creating a friction force that makes the outer body (2) and the disk-shaped support (3) rotate together with one another.
A labelling machine (10) with a carrousel, comprising a carrousel (11) and a plurality of plates (1) according to any of claims 1 to 8, each plate (1) being rotatably mounted on the carrousel (11).