Method and device for centring labels during application onto small surfaces

Abstract: Method and device for centring labels (2) while applying them to small surfaces includes picking up a label (2) from a feeding line (6) by vacuum operated picking up means (13) connected to a tubular body (10) which communicates with suction means. These picking up means are subsequently introduced into a sized-apertured member (17) coaxial therewith and connected to a sleeve (14) which slides on the tubular body (10) thus limiting, in a transitory step, the above mentioned depression in order to centre the label (2) with respect to the picking up means (13). The sized-apertured member (17) is set centred axially on a container (3) by axial movement of the sleeve (14). Subsequently, the picking up means (13) are moved with respect to the sleeve (14), so as to apply the label (2) onto the container (3).

Description: The present invention relates to application of labels to containers having sides of small surfaces and the like. It is necessary, e.g. in cosmetics, to apply a label to the bottom or to the cover of small cylindrical or similar containers, to indicate some product characteristics or similar specification. In particular, such a label, of a circular shape, is usually applied on the bottom of lip-stick casings. The labels are applied to the containers automatically during a packaging cycle by machines that take over the labels from a feeding line and transfer them to the corresponding container surfaces. One problem deriving from the application of the above mentioned labels is a proper centring of the labels with respect to the container surfaces, where they are to be attached. Small deviations of the labels from the position taken in the packaging step, e.g. upon advancement along the feeding line, result in deviations from the correct centring position. This deviation, often very big, considerably jeopardises the package aspect, which obviously leads to a damage to the product image. Moreover, sometimes, particularly when the label size is very similar to the size of the surface to which it is to be applied, the label can protrude from the surface edge. From the publication GB1437463 a labelling device is known which applies a self-adhesive label to an article fed to a labelling station. The device includes a label support for receiving a label released from a backing strip acted upon by pneumatic means aimed at displacing the label into engagement with the label receiving surface. Guide means are arranged to effect displacement of a misaligned label parallel to the label receiving surface, this means serving to position the label in an accurately defined position on the receiving surface. A locator means, optionally constituted by the guide means, locates an article in the labelling station in an accurately defined position relative to the accurately defined position on the label receiving surface. The label support is displaceable in a direction perpendicular to the label receiving surface thereof, close to or in engagement with the article disposed in the labelling station to transfer the label from the said label receiving surface to the accurately define position on the article. In the device disclosed by GB1437463, the label support is located outside of the label guide means when the label is applied to a container or other label receiving surface. The object of the present invention is to propose a method that allows to automatically apply labels onto small surfaces, in particular of circular or similar shape, with precise centring of the labels on the surfaces. Another object of the present invention is to provide a device that carries out the above mentioned method by structurally simple and practical means. Yet another object of the invention is to provide a versatile centring device for application of labels of different shapes and sizes to correspondingly different surfaces. The above mentioned objects are achieved in accordance with the contents of the claims. The characteristics of the invention will become apparent from the following description with specific reference to the enclosed drawings, in which: Figures 1, 2, 3, and 4 show in a schematic plan view, subsequent working steps of the subject method for centring labels on the small surfaces; Figure 5 shows, in a longitudinal section, the device for centring labels; Figure 6 shows, in the same longitudinal section, an enlarged particular of this device; Figures 7, 8 and 9 show the above mentioned device in a cross sectional view taken respectively along plans VII-VII, VIII-VIII and IX-IX of fig. 6; Figures 10, 11 and 12 show respective schematic views of the above mentioned particular, in different working steps. The above drawings show the device 1 for centring labels 2 while they are applied to relative surfaces, in particular to the bottom or the cover of cylindrical or similar containers 3. During the application step of label 2, the containers 3 are carried inside respective housings made radially in a carrousel 4, which rotates stepwise. The device 1 is supported by a turret 5 mounted rotatably beside a feeding line 6 of the labels 2 to be applied and driven in an alternate oscillatory movement in a suitable phase relation with the carrousel 4 stepwise movement. Along the feeding line 6, the labels 2 are arranged, regularly spaced apart, on a band 8, which, near the label delivering area, follows the contour of an angled piece 9 so as to facilitate the labels 2 detachment. The turret 5 operates the device 1 rotation between a position in which the labels 2 are taken over from the feeding line 6 and in which the device 1 is perpendicular to this feeding line 6, and a position in which the labels 2 already detached from the band are applied to the containers 3 and in which the same device 1 is lined up with a relative container 3 carried by the carrousel 4. The second position is substantially orthogonal with respect to the first one. More precisely, as seen in fig. 5, the device 1 is equipped with a tubular body 10, rigidly fastened to a slide member 11 carried by the turret 5. A suitable reciprocating actuator, only a stem 7 of which is visible, drives the slide member 11 in a linear way with respect to the turret 5. A broken line indicates the position of the slide member 11 at the end of the label 2 application stroke, as will be better explained later. A suitable coupling 12 connects the rear end of the tubular body 10 with known, not shown, suction means which create depression in the channel 100 defined by the same tubular body 10. At its fore end, the above mentioned channel 100 of the tubular body 10 defines a receiving housing for a label picking up head, indicated with 13. The tubular body 10 is introduced into a sleeve 14, in coaxial relation thereto. Near a threaded tang 14a, the sleeve 14 features, screwed thereto, a correspondingly tubular terminal part 15, acting as centring means. At its end turned outside, the terminal part 15 features a conical mouth 16, aimed at centring the container 3; a broken line indicates the position assumed by the terminal part 15 during the centring of the container 3. A sized-apertured bushing 17 for centring a relative label 2, is joint to the terminal part 15. This sized-apertured bushing 17 is cylindrical and the internal rim of one of its extremities is bevelled so as to define a conical surface that is a continuation of the conical mouth 16. The sleeve 14 supports a pair of rollers 18, diametrically opposite and rotating, designed to engage respective sections of a stationary cam 19. This cam 19 causes relative sliding of the sleeve 14 with respect to the tubular body 10, in contrast to elastic action performed by a helical spring 20 mounted on the same tubular body 10 near an axial cavity of the sleeve 14. The sleeve 14 is equipped with a transversal pin 21 that engages a groove 22 made longitudinally with respect to the tubular body 10, so as to prevent reciprocal rotation of the sleeve 14 and the tubular body 10. As can be seen in detail from fig. 6, the picking up head 13 includes a tubular stem 23 guided tightly through a tube 24, screwed to the end of the tubular body 10. The tubular stem 23 is axially pushed by a spring 25 acting on a shoulder 26, which acts as a stop for the tube 24. At its free extremity, the tubular stem 23 carries a head 27, equipped with an axial hole, for taking over the label 2 to be applied. Upstream of the area of the picking up head 13 receiving seat, the tubular body 10 features a first pair of holes 28 and a second pair of holes 29, suitably spaced apart. The holes 28 and 29 are made along crossing diametrical lines of the tubular body 10, on two planes transversal to the tubular body 10 axis, so as to open into the tubular body axial channel 100 (see figs 7 and 8). In a working step, which will be better described in the following, the holes 28, 29 communicate with a corresponding series of holes 30 made along crossing lines of the sleeve 14 lying on a plane transversal to the sleeve axis, near the tang 14a. The holes 30 communicate with respective longitudinal grooves 31, made on the external surface of the tang 14a of the sleeve 14 and open at the front end of this latter (see also fig. 9). According to the method for centring the labels 2, a label to be applied is taken over from the feeding line 6, operated stepwise in the direction indicated with arrow A (fig. 1). To carry it out, the device is brought to the picking up position, with the axis perpendicular to the feeding line 6, in the region of the outlet of the same line 6. During the turret 5 rotation, the rollers 18 follow the stationary cam 19 path and move the sleeve 14 backward with respect to the tubular body 10 and in contrast with the elastic action of the elastic means 20. As a consequence, the picking up head 13 is extracted from the terminal part 15. During the taking over step, the picking up head 13 is set in depression by the channel 100 of the same tubular body 10, so as to grip a label 2. During this step in which the label 2 to be applied is taken over, the carrousel 4 is rotated stepwise in direction indicated by arrow B, so as to prepare a container 3 in the label application station. Then, the turret 5, supporting the device 1, is rotated in the direction indicated with arrow C in fig.2. During this rotation, the action of the spring 21 keeps the rollers 18 in contact with the cam 19, so as to determine the movement of the sleeve 14 with respect to the tubular body 10. Due to the relative movement between the tubular body 10 and the sleeve 14, the picking up head 13 is brought to a retracted position inside the terminal part 15 of the sleeve, until the label 2 is introduced into the sized-apertured bushing 17. When the rotation is completed, the device 1 is axially aligned with the container 3 held by the carrousel 4 in the label application position. The label is inserted into the sized-apertured bushing 17. It is to be pointed out that during the transitory step in which the label 2 is introduced into the sized-apertured bushing 17, the depression acting through the picking up head 13 is suitably limited, so as to allow a controlled movement of the label 2 in order to centre it with respect to the picking up head 13. In fact, during the label 2 taking over, when the picking up head 13 is extracted from the terminal part 15, the cross-like holes 28 and 29 of the tubular body 10 are closed by sleeve 14 with this tubular body 10 inserted therein, as is seen in detail in fig. 10. A bearing 32 is suitably inserted between the tubular body 10 and the tag 14a of the sleeve. Thus, the whole depression created by suction means connected to the channel 100 of the tubular body 10 is applied through the picking up head 13. On the other hand, when the picking up head 13 is brought to the retracted position inside the terminal part 15, the above mentioned cross-like holes 28 and 29 are set in communication with corresponding discharge holes 30 of the sleeve 14 (see fig. 6). In this way, a part of suction action applied through the channel 100, is neutralised by the grooves 31 communicating with the holes 30. Therefore, during introduction of the label 2 into the sized-apertured bushing 17, the depression in the region of the picking up head 13 is suitably reduced. Therefore, the label 2 can move slightly, taking a perfectly centred position with respect to the picking up head 13 due to the sized-apertured bushing 17, which reproduces the shape and dimensions of the same label. Subsequently, the slide member 11 is moved with respect to the turret 5, so as to bring the device 1 until it strikes against the container 3, as seen in fig. 4. Operation of the slide member 11 determines movement of the tubular body 10, integral thereto and carrying the sleeve 14. During a first step of the slide member 11 stroke, the terminal part 15 of this sleeve 14 is brought to engage frontally, by the conical mouth 16, the container 3, so as to obtain a centred position of the same container with respect to the axis of the sized-apertured bushing 17, as shown in detail in fig. 11. Further movement of the slide member 11, in the stop position indicated in fig. 5 with 11a, determines relative sliding of the tubular body 10 with respect to the sleeve 14, overcoming the elastic action of the spring 20, until the head 27 of the picking up head 13 is brought to contact the bottom of the container 3, as shown in detail in fig. 12. Thus the label 2 carried by the picking up head 13 is applied to the container 3. It is to be noted that, during the application of the label 2 to the container 3, the action of the picking up head 13 is elastically pushed by the spring 25, that acts on the shaft 23, so as to guarantee a gradual and constant pressure on the container 3. Therefore, the illustrated method and device allow best application of labels onto containers, assuring that the labels are set perfectly centred on the surfaces. An important feature of the subject device is that it allows an easy change of size of containers and relative labels, i.e. application of labels of different shapes and sizes to correspondingly different surfaces. In fact, it is sufficient to change the terminal part 15 of the sleeve 14 carrying the sized-apertured bushing 17, whose cross-section matches the labels cross-section. This substitution is very cheap and quick to perform.

Claims: Method for centring labels while they are applied to small surfaces, including: taking over a label (2) from a feeding line (6) by vacuum operated picking up means (13) fastened to a tubular body (10) slidingly inserted in a sleeve (14); introducing said picking up means (13) into a sized-apertured member (17), located in coaxial relation therewith, while limiting, in a transitory step, the action of depression created by the vacuum in order to centre said label (2) with respect to the same picking up means (13); coaxial centring of a container (3) with respect to said sized-apertured member (17); driving said picking up means (13) to move axially until they are situated inside said sleeve, to apply said label (2) to said container (3). Device for centring labels while they are applied to small surfaces, the device including: a tubular body (10), aimed at being set in communication with suction means and equipped, on one end, with vacuum operated picking up means (13) for taking over a single label (2); means (5,11) for reciprocating motion of said tubular body (10) between a position, in which a label (2) is taken over from a feeding line (6) and a position, in which this label (2) is applied to a relative container (3) ; a sleeve (14) slidingly mounted on said tubular body (10) and aimed at being moved axially with respect to said tubular body (10) between two extreme positions, namely a label taking over position and label application position, with said picking up means (13) being situated outside said sleeve (14) in the taking over position; sized-apertured means (17) axially connected to said sleeve (14), into which said picking up means (13) pass through in a transitory step to centre the label (2) being applied with respect to said picking up means (13); the device being characterised in that said picking up means (13) are situated inside said sleeve (14) in said label application position. Device, according to claim 2, characterised in that upstream of the area where said picking up means (13) enter, the tubular body (10) features transversal holes (28,29), which are set in communication, during said transitory label (2) centring step, with corresponding discharge holes (30) made on the sleeve (14),in order to reduce the depression created in the picking up means (13). Device, according to claim 2, characterised in that said sleeve (14) supports, axially mounted thereto, a changeable terminal part (15), having similar tubular shape and carrying said sized-apertured means (17). Device, according to claim 4, characterised in that, at its end turned outside, said terminal part (15) features a conical mouth (16) for axial centring of said container (3). Device, according to claim 4, characterised in that said sized-apertured means (17) feature a cylindrical bushing, whose cross-section matches the contour of a label (2) to be applied; an internal rim of one extremity of the cylindrical bushing is bevelled so as to define a conical surface that is a continuation of a conical mouth (16) made in said terminal part (15). Device, according to claim 2, characterised in that said tubular body (10) is rigidly fastened to a linearly moving slide member (11) carried by a turret (5), that rotates between a position in which said label (2) is taken over from said feeding line (6) and position in which the label (2) is applied to a container (3), with said slide member (11) being moved axially in order to centre said container (3) with respect to said sleeve (14) and subsequently, to apply said label (2) onto said container (3). The device, according to claim 2, characterised in that said sleeve (14) supports a pair of rollers (18), that engage a stationary cam (19) which causes the relative sliding of the sleeve (14) on the tubular body (10), in contrast with elastic action performed by a helical spring (20) mounted on the same tubular body (10). The device, according to claim 2, characterised in that said picking up means (13) feature a tubular stem (23) guided tightly inside said tubular body (10) and equipped, externally with respect to said body (10), with a head (27) for taking over the label (2) to be applied on the container (3), with said tubular stem (23) axially pushed by a spring (25), that acts elastically against the pressure performed during the label (2) application step.

Inventors: GUCCI GIACOMO, LABARDI PAOLO, GUCCI, GIACOMO, LABARDI, PAOLO
Applicants: NERI S P A, NERI S.P.A.
Application year: 1997
Main classification: B65C9
IPC codes: B65C9