A device for changing the angular relation between a carousel conveyor and a kinematically-linked labelling group of a labelling machine

Abstract: The device disclosed comprises a support frame (1) to which an internal hollow shaft (2) and an external hollow shaft (9) are constrained, the shafts (2 and 9) being coaxial and connected by cogwheels (7 and 12) to the command shaft of the conveyor line and to the command shaft of the labelling group, and being further connected to each other by a coaxial joint (8), which is movable along an axis common to the shafts (2,9) in order to vary the angular relationship between the shafts.

Description: The invention relates to a device for changing the angular relation between a kinematically-connected carousel conveyor and a labelling group of a labelling machine. Specifically, but not exclusively, the device is useful in labelling machines where the label application position has to be changed. Such label application is performed by special applicator tools on moving objects on a motorised carousel conveyor. The need to change the label application position arises, for example, in cases where objects of different shapes and sizes are to be labelled: obviously, the labelling machine organs have to be repositioned to the new references required by the shape of the new objects. Such a repositioning operation is complicated, however, since the labelling group must stay synchronised with the movement of the carousel: it is usually achieved through mechanical transmissions connecting the labelling machine to the carousel motorisation. At present the labelling group is adapted to a new shape of object to be labelled by rephasing the angular position of a command shaft of the labelling machine organs with respect to the command shaft of the conveyor. Known devices of this type exhibit some drawbacks, however, regarding their constructive complexity, which is due to the fact that they cannot be applied in cases where the labelling group can only rotate about a vertical axis. WO-A-91/14625 discloses an equipping machine for treating vessels of different shape. The machine has a revolving platform provided with rotary plates, each with an associated positioning element which cooperates with radial cams. The positioning elements and/or the radial cams must be adjusted when it is necessary to change the form or the type of vessels. Said document does not overcome the above mentioned drawbacks of the prior art. A principal aim of the present invention is to provide a constructionally simple but economical and practical device which, in a very short time, enables the labelling machine organs to be repositioned to correspond with the shape and size of an object transiting on the conveyor. One advantage of the present invention is that it enables the labelling machine organs to be repositioned continuously and without the need to stop the machines. These aims and advantages and others besides are all achieved by the device of the invention, as it is defined in the claims, wherein two coaxial shafts are connected to a joint by means of pawls engaging in guide grooves in the joint. Further characteristics and advantages of the present invention will better emerge from the detailed description that follows, of an embodiment of the invention, illustrated in the form of a non-limiting example in the accompanying drawings, in which: figure 1 shows a schematic section in vertical elevation; figure 2 shows a frontal view of a detail of figure 1; figure 3 shows a lateral view of the detail of figure 2. With reference to the drawings, 1 denotes a support frame provided with a vertical-axis cylindrical support 3. A first, internal hollow shaft 2 is rotatably coupled to tie support 3 by means of bearings 4 distanced by a spacer 5. A collar 6 is screwed on a bottom end of the support 3, to support the first shaft 2. A cogwheel 7 is solidly keyed on the first shaft 2. A second, external hollow shaft 9, coaxial to and external of the internal hollow shaft 2, is rotatably coupled to the internal hollow shaft 2 by means of two bearings 10. An elastic safety ring 11, mounted on the internal hollow shaft 2, supports the external hollow shaft 9. A cogwheel 12, arranged inferiorly to the wheel 7, is solidly keyed on the external hollow shaft 9. The two hollow shafts 2 and 9 are connected to each other by a cup-shaped cylindrical joint 8 which is rotatably coupled to a cylindrical support 13. A pair of bearings 14 permits of rotating the joints 8 about the cylindrical support 13. The lower bearing 14 rests on a shoulder 15. A collar 16 is screwed to the cylindrical support 13 to prevent the cylindrical support 13 from sliding out of the joint 8. The cylindrical support 13 is rigidly constrained to a vertical-axis screw-jack 17 which is vertically translated by a motor. The motor 18 is fixed to the base of the frame 1. The screw-jack 17 translation distances are measured by a transducer of the potentiometer type 23, provided with a cursor 24 made solid to the screw-jack 17 by a staff 25 and a clamp 26. Figures 2 and 3 show the conformation of the joint 8. On its cylindrical part the said joint 8 exhibits several vertical straight grooves 20 as well as several helical grooves 19, arranged symmetrically with respect to the rotation axis. In the illustrated example the joint has two straight grooves 20 and two helical grooves 19. The joint 8 is external of the first hollow shaft 2 and internal of the second hollow shaft 9. Two pawls 21 are solidly connected to the second hollow shaft 9 and arranged symmetrically with respect to the rotation axis. The pawls 21 project internalwise of the shaft 9 and engage in the helical grooves 19. Two other pawls 22 are solidly connected to the first hollow shaft 2 and are arranged symmetrically to the rotation axis. The pawls 22 project externalwise of the shaft 2 and engage in the vertical grooves 20. Figure 1 shows only part of one of the pawls 22. The above-described device is destined to be connected with applicators of a labelling machine. Precisely, applicators are the tools of the labelling machines which apply labels on an object, such as a bottle, in movement on a conveyor. The cogwheel 12 is destined to mesh with a further cogwheel connected to a mechanical transmission system of known type, by means of which the above-mentioned label applicator organs are activated. The cogwheel 7 is moved by a cogwheel connected to gearing which move the wheel of the labelling machine. The motor can be the same as the one which moves the objects to be labelled on the transport line. The cogwheel 7 transmits the movement that it receives from the wheel of the labelling machine to the cogwheel 12 through the joint 8. The movement of the objects to be labelled is thus synchronised with the movements of the applicator tools of the labelling machine. The above applies to objects having the same size and shape. For objects having varying sizes and shapes, obviously the point of application has to be changed. In order to do this, first the reciprocal angular position of the cogwheels 7 and 12 has to be changed, producing a displacement of the transmission downstream of the cogwheel 12 which finally results in a relative displacement of the applicator tools with respect to the conveyor bearing the objects to be labelled. This relative displacement of the cogwheel 7 and the cogwheel 12 is made possible even while the same wheels 7 and 12 are in movement by a vertical translation of the joint 8, activated by the motor 18. During the translation, the pawls 21 and 22 slide one pair in the helical grooves 19 and the others in the vertical grooves 20. The different conformation of the grooves 19 and 20 causes the shafts 2 and 9 to rotate with respect to one another, the entity of the rotation (deriving from the vertical displacement of the joint 8) being measured by the potentiometer 23. Thus, every different shape of object to be labelled corresponds to a position of the joint 8, through a signal provided by the potentiometer 23.

Claims: A device for changing an angular relation between a carousel conveyor and a kinematically-linked labeling group of a labeling machine, comprising: a support frame (1); a first hollow shaft (2) and a second hollow shaft (9) constrained to the support frame (1) with freedom to rotate about a same axis, the first hollow shaft being connected to a command shaft of a conveyor line and the second hollow shaft being connected to a command shaft of a labeling organ assembly; a joint (8), coaxial with the first hollow shaft (2) and the second hollow shaft (9) and constrained to the support frame (1) with freedom to rotate about the axis as well as freedom to slide along the axis on command; the joint (8) exhibiting at least one longitudinal guide groove (20) developing along a same direction as the axis and at least one oblique guide groove (19) developing inclinedly to the axis; at least one pawl (22), solid to the first hollow shaft (2) and one pawl (21) solid to the second hollow shaft (9), which pawl (21) and at least one pawl (22) engage in one of the guide grooves (19, 20) and means for displacing the joint (8) along its axis to make the pawls (21, 22) move in their respective guide grooves (19, 20) in order to vary the angular relation between the first and the second shaft. A device as in claim 1, wherein the joint (8) is rotatably coupled to a support (13), the support (13) being solid with a screw-jack (17) activated by a motor (18) to translate parallel to the axis. A device as in claim 1, comprising a measuring instrument of an axial displacement of the joint (8). A device as in claim 3, wherein the instrument of measurement is a potentiometer (23), comprising a cursor (24) solid to the joint (8). A device as in claim 1, comprising a cogwheel (7) keyed on the first hollow shaft (2) and another cogwheel (12) keyed on the second hollow shaft (9). A device as in claim 1, wherein: the first hollow shaft (2) is rotatably coupled to a support (3), the support (3) being solid to the support frame (1) by means of two bearings (4); the external hollow shaft (9) is arranged externally and coaxially to and is rotatably coupled to the first hollow shaft (2) by means of two bearings (10); the joint (8) is cup-conformed and has a cylindrical portion arranged between the first hollow shaft (2) and the second hollow shaft (9); the guide grooves (19, 20) are predisposed on the cylindrical portion. A device as in claim 1, wherein the joint (8) comprises two helical guide grooves (19) arranged symmetrically with respect to the axis and two longitudinal guide grooves (20) in opposite positions to each other.

Inventors: ORLANDI IRENEO, PEDERCINI MAURIZIO, ZACCHE VANNI, ORLANDI, IRENEO, PEDERCINI, MAURIZIO, ZACCHE', VANNI
Applicants: ALFA COSTR MECC SPA, ALFA COSTRUZIONI MECCANICHE S.P.A.
Application year: 1993
Main classification: B65C9
IPC codes: B65C9