Conveying device, in particular wheel for forming packaging envelops for cigarettes, or similar

Abstract: A conveying device, in particular of a wheel forming packaging envelops for cigarettes, or similar comprising at least one peripheral cavity (a) open on the radially external side, preferably a plurality of said cavities (A) for housing a group of cigarettes (G) and for conveying the same from a feeding station (SA) to at least one further discharge station (SC) along a circular or substantially circular track, said cavities (A) being at least partially open also on their radially internal side, for passage through the same of follower means (6) and pusher means (7) displaceable in a radial direction relative to the circular track and provided in the feeding station (SA) and discharge station (SC) respectively. According to the invention the pusher means and the follower means (6, 7) are activated by means of a kinematic motion like an articulated polygon.

Description: The invention relates to a conveying device consisting of a stepwise rotating wheel forming packaging envelops for cigarettes, or similar, and comprising a plurality of peripheral cavities open on the radially external side and provided for housing each a group of cigarettes and for conveying the same from a feeding station to a discharge station along a circular track, said cavities being partially open also on their radially internal side for passage through the same of a follower in the feeding station and off a pusher in the discharge station, whereas the follower and the pusher are displaceable in a radial direction relative to said circular track and are actuated each by means of an associated articulated polygon being mounted on radial supporting rods which form part of said articulated polygons and which are given alternating motion in direction of their longitudinal axis, and whereas each articulated polygon comprises a four-bar linkage with a first and a second oscillating lever pivoted with one end to the supporting rod carrying the follower or the pusher and pivotably interconnected by a connecting rod which extends in a substantially parallel direction to said supporting rod, the first of said oscillating levers being pivoted in to a driven lever. A conveying device of this kind is known from the document GB-A-2191166. In this known device the follower and the pusher along with the respective articulated polygons are mounted on the conveyor wheel. In particular in cigarette packing machines, the internal envelop of the packet is made by envelopping a sheet of wrapper, especially foil, around a group of cigarettes having a predetermined number of cigarettes for the packet, these cigarettes are furthermore arranged in an orderly position foreseen in the packet. This is carried out by feeding an arranged group of cigarettes together with a sheet of wrapper into a cavity of a so-called forming wheel. The forming wheel is put into motion in steps and conveys the group of cigarettes and wrapping envelop of the same from one folding station to another of said wrapping sheet around the group of cigarettes, up to a discharge station where the group of cigarettes enveloped in the wrapper is transferred to a further pack forming station. This one can also be formed by a forming wheel which, in particular for making soft pack packets, is substantially the same as the wheel for forming the external envelop. Since the packing machines operate at very high speeds, each unit of the same is activated with great rapidity and frequency. In these conditions , it becomes necessary to sufficiently lubricate the moving parts of the operational units. This necessity is in contrast with the necessity, as a rule, to keep the tobacco and the cigarettes clean avoiding contamination. Also, taking into account the fact that the moving parts are subject to considerably heating, the necessary lubrication entails the possibility of staining the cigarettes both directly as well as by fumes of the lubricant. Therefore, one is always compelled to find a satisfactory balance between the two contrasting requirements, that is to keep the operating units sufficiently lubricated and protect the product as much as possible from contamination. In particular, up to now the follower means and the pusher means discharging in the feeding and discharge station of the forming wheel were supported displaceable thanks to racks which came out of and went back into a central box in the area near the hub of the forming wheel. These and the gears transmitting the motion in cooperation with the same require considerable lubrication. Consequently, every time the racks enter into position of maximum extraction, they cause lubricant to be carried out. The motion in radial direction towards the cavities and which is executed with extreme rapidity and the stop in said extreme position cause, however, a further inconvenience in that the lubricant deposited on the rack is in a way accelerated and eventually projected in direction of the product. A further limitation to the possibility of avoiding the aforesaid inconvenience is given by the fact that due to the considerable quantity of operating parts which must all operate in perfect synchronism and at considerable speed, as well as with motions of continued acceleration and deceleration, each part must necessarily be created with a mass and in a manner to offer the smallest possible inertia. The invention has therefore the purpose to create a conveying device of the kind described in the beginning and in which the follower in the feeding station, the pusher in the discharge station and the respective articulated polygons are made in such a way as to prevent the aforesaid inconveniences, limiting considerably the need for lubrication and the danger to stain and/or contaminate the product and offering the smallest inertia possible, the whole without resulting constructional excessively complex or costly. The invention attains the aforesaid purposes by the combination of the following features: a) the follower, the pusher and the associated articulated polygons are provided in stationary positions, b) the driven lever is fixed on a stationary positioned drive shaft which is actuated with an alternating rotary motion, and for suppression/correction of the tangential component c) the second oscillating lever is fulcrumed with its end opposite to the supporting rod at an eccentric fulcrum point on a circular or annular plate provided in a stationary position and revolving around its own axis, said fulcrum point forming a crank button, d) the drive lever is pivotably connected to an eccentric fulcrum point of said circular or annular plate by means of a connecting rod, e) the first oscillating lever is pivoted with its end opposite to the supporting rod to an end rod which extends in a substantially parallel direction to the supporting rod and is fulcrumed at a fixed shaft in a freely oscillating manner. Further improvements of the conveying device according to the invention are contained in the dependent claims. The features of the invention and the advantages arising from the same will better result from the following description of an executive example illustrated in the attached drawings, in where: Fig. 1, illustrates a perspective view of the follower and pusher devices associated with one part of the forming wheel. Figs. 2 and 3, illustrate two axial schematic views of the follower and the pusher devices according to fig. 1 in the radially retracted position and in the maximum radial advanced position respectively. Fig. 4 is a schematic view of the assembly, partially a cross-section of the forming wheel and of the follower and pusher activating means. Fig. 5 is an enlarged view in the radial direction of the wheel of one of the two pusher and follower devices. Fig. 6 shows schematically the drive transmission of the shafts activating the device of the follower and the one of the pusher. With reference to fig. 4, a forming wheel 1 of the envelop, for example of foil, around an ordered group of cigarettes G, is formed by two coaxial discs which have no rigid connection between them, but are supported revolving one in front of the other and at a previously established distance around a common axis on separate shafts 2, connected only dynamically between each other. The two discs are driven in steps, for instance by a common drive shaft (not shown) from which two identical kinematic drive chains depart terminating in a Maltese cross 3. This arrangement allows to leave an intermediate space completely free between the two discs forming the wheel. The discs 101 are provided in axially coinciding positions with shaped cavities 201 which form two end cradles, these constitute the housings in which the group of cigarettes G are inserted into the feeding station A together with the respective sheets F. Each disc is mounted on the front end extremity of a tubular shaft 2, the opposite extremity of which carries the Maltese cross in a manner to revolve together. Between the discs the drive kinematics 5 of the follower means 6 and the pusher means 5 which act in an radial sense of the wheel on the tangential radially more internal side of the group of cigarettes G with the associated sheet. As can be better understood from fig. 2 and 3, the follower has the function to cooperate with the tangential side of the group of cigarettes turned towards the forming wheel, holding the sheet F against them, while the conveyor acts on the opposite end of the group of cigarettes. The follower 6 and the conveyor 4 which is part of the station combining the group of cigarettes with the sheet F without disturbing the formation of said group of cigarettes G and retaining the sheet F in the present relative position with respect to the cigarette group G, necessary to guarantee during the successive folding phases the complete wrapping of the group of cigarettes G in the envelopping sheet F. The discharge pusher means are driven in the discharge station SC which is arranged diametrically opposite to the feeding station SA and which are used to transfer the group of cigarettes G completely envelopped in the wrapping sheet F out of the forming wheel to a successive operating station, as for example to a station forming the outer envelop, soft or hard, of the cigarette packet (not shown). The arrangement of the two feeding and discharge stations SA, SC, allows to make the follower and pusher devices in a substantially identical manner as the drive kinematics 5 of the devices are arranged in a rational symmetry relative to each other and with regards to the axis of rotation of the wheel 1. Therefore, in the following description of the said drive kinematics only one of the two devices will be described in detail, referring to the other only when that should be necessary. The follower and the pusher 6, 7 are fixed on the front extremity of a substantially radial supporting rod 8 which is part of an articulated polygon, the axes of articulation of which are parallel to the axis of rotation of the forming wheel. The articulated polygon, an articulated pentalateral or eventually a hexalateral allows to carry out a displacement of the follower and of the pusher which is perfectly rectilinear and radial, correcting the components of the motion in the tangential direction of the wheel 1. Said articulated polygon is formed by the supporting rod 8 of the follower 6 and the pusher 7. At the opposite end the rod 8 is pivoted at 109 to a lever 9 which in its central area is pivoted at 209 to a driven lever 10, while the other extremity of the lever 9 is pivoted at 309 to a second end lever 11 which extends towards the supporting end of the pusher and follower 6, 7 and which at an intermediate level of the same is fulcrated on a fixed axis 12 in a freely oscillating manner. The fixed axis 12 of the end lever 11 is fixed on a stationary support plate which can be supported by a stationary element integral with the framework of the machine which protrudes at the inner side of the wheel 1 through the tubular support shaft 2 of the disc 101 and/or by a supporting element connected to the framework of the machine which protrudes radially from below between the two discs, namely from a zone of the wheel were no work station is foreseen and where the cavities travel empty, this said part forming the return path of the cavities from the discharge station SC to the feeding station SA. A further connecting rod 13 is pivoted to the driven oscillating lever 10 which extends in a substantially parallel position to the one of the supporting rods 8 and the end rod 11 and the other end of which is fulcrated in eccentric position 114 to a circular 14 or in particular annular plate, revolving around its proper axis like a crank button. A further oscillating lever 15 connects in an articulated manner an intermediate point of the lever 8 which carries the follower or the pusher 6,7 with an eccentric fulcrum point of the circular plate or ring 14 and which in the example shown is coaxial to the eccentric fulcrum 114 of the connecting rod 13. Thanks to this construction, the driven oscillating lever 10 activates both the motion in the radial sense of the rod 8 as well as the button of the crank 114 constituted by the circular plate 14 and which does displace or rather oscillate transversally the front end of the support rod 8 in order to compensate in sense of its suppression the component of the tangential displacement relative to the forming wheel 1 which otherwise the extremities ,on which are the follower and the pusher 6, 7, would carry out. The end rod 11 causes a further suppressive compensation of the tangential motion component. In fig. 1 the follower is shown in a radially retracted position, while the pusher 7 is in radially outwards extended position. The figs. 2 and 3 however show the real working conditions, where the follower 6 and the pusher 7 are both in the retracted and in the outward extended position, reaching the controlled operating condition of the feeding phases of a new group of cigarettes and the discharging of one group of cigarettes G wrapped in a finished envelop carried out contemporaneously. With reference to figures 4 and 5, the driven oscillating levers 10 are fixed with their extremity opposite to the articulated one to the remaining components of the articulated polygon on the extremity of a drive shaft 18, 18' separate for the follower 6 and the pusher 7. The shafts 18, 18' are guided in a revolving manner parallel to each other through the tubular drive shaft of the disc 101 of the forming wheel and connect with one extremity to the oscillating levers 10 through a window 119 in the support plate 19. The other extremity protrudes from the head of the tubular support shaft of the disc 101 and connects dynamically to a drive transmission or rather to the output shafts 120 of a group 20 transforming a continuos motion into an alternating rotary motion with a prefixed angular amplitude, the input shafts of which are connected to the kinematic chain of the machine drive. The said group 20 can be constituted by a so-called oscillator, where the input shafts 220 drive a cam 320 of the desmodromic type and with which a set of rollers 420 cooperate supported by small radial arms 520 arranged at a prefixed relative angular distance and which are keyed on the output shaft 120. The output shafts 120 each carry a small radial arm 21 which by means of a connecting rod 22 are articulated to radial arm 23 fixed on the respective drive shaft 18, 18' of the follower 6 and pusher 7. As evidenced in fig. 6, the rotary symmetrical arrangement of kinematic motions of the articulated polygons associated with the follower 5 and pusher 6 is also reflected in the arrangement of the cams 320 and the rollers 420, and the transmissions 21, 22, 23 for the two shafts 18, 18'. Advantageously, the group 20 may present only one single input shaft 220, on which both cams are mounted offset by 180 degrees to each other and each cooperating with a set of rollers 420 carried by one of the two exit shafts 120. Naturally, the invention is not limited to the executive form here described and illustrated but can be amply varied, above all constructional. In particular it is possible to foresee any other equivalent type of articulated polygon or of the drive transmission of the same, while the forming wheel according to the invention can be used for whatever type of wheel or circular conveyor, in particular also for the soft packets. All without abandoning the informatory principle shown above and claimed hereafter.

Claims: Conveying device consisting of a stepwise rotating wheel (1) forming packaging envelops for cigarettes, or similar, and comprising a plurality of peripheral cavities (201) open on the radially external side and provided for housing each a group of cigarettes (G) and for conveying the same from a feeding station (SA) to a discharge station (SC) along a circular track, said cavities (201) being partially open also on their radially internal side for passage through the same of a follower (6) in the feeding station (SA) and off a pusher (7) in the discharge station (SC), whereas the follower (6) and the pusher (7) are displaceable in a radial direction relative to said circular track and are actuated each by means of an associated articulated polygon (8, 9, 15) being mounted on radial supporting rods (8) which form part of said articulated polygons and which are given alternating motion in direction of their longitudinal axis, and whereas each articulated polygon comprises a four-bar linkage with a first and a second oscillating lever (9, 15) pivoted with one end (109, 108) to the supporting rod (8) carrying the follower (6) or the pusher (7) and pivotably (114, 209) interconnected by a connecting rod (13) which extends in a substantially parallel direction to said supporting rod (8), the first (9) of said oscillating levers being pivoted in to a driven lever (10), characterized by the combination of the following features: a) the follower (6), the pusher (7) and the associated articulated polygons are provided in stationary positions, b) the driven lever (10) is fixed on a stationary positioned drive shaft (18, 18') which is actuated with an alternating rotary motion, and for suppression/correction of the tangential component c) the second oscillating lever (15) is fulcrumed with its end opposite to the supporting rod (8) at an eccentric fulcrum point on a circular or annular plate (14) provided in a stationary position and revolving around its own axis, said fulcrum point (114) forming a crank button, d) the drive lever is pivotably connected to an eccentric fulcrum point (114) of said circular or annular plate (14) by means of a connecting rod (13), e) the first oscillating lever (9) is pivoted with its end (309) opposite to the supporting rod (8) to an end rod (11) which extends in a substantially parallel direction to the supporting rod (8) and is fulcrumed at a fixed shaft (12) in a freely oscillating manner. Device according to claim 1, characterized by the fact that the crank button fulcrum point (114) of the second oscillating lever (15) to the circular or annular revolving plate (14) is coaxial to the fulcrum point of the connecting rod (13) to said revolving plate (14). Device according to claim 1 or 2, characterized by the fact that the forming wheel (1) is constituted by two coaxial discs (101) which have no rigid connection between them and are supported revolving in a synchronized manner one in front of the other at a previously established distance around a common axis on separate shafts (2) at least one of which is tubular, whereas the follower (6), the pusher (7) and the associated articulated polygons are provided in the intermediate space between said discs (101) and the drive shafts (18, 18') pass through the interior of said tubular shaft (2) and are dynamically connected each with its extremity outside the wheel (1) to a drive unit (20) and with its extremity protruding between the discs (101) of the wheel (1) to the driven lever (10) of the associated articulated polygon. Device according to claim 3, characterized by the fact that the drive shafts (18, 18') are connected by means of a transmission (21, 22, 23) to the output shafts (120) of an oscillator with parallel axis (20). Device according to claim 4, characterized by the fact that the parallel axis oscillator (20) has one input shaft (220) and two output shafts (120) each for the drive shafts (18, 18'), each of the output shafts being dynamically connected to one of two cams (320) supported by the same input shaft (220) by means of a set of rollers (420) on angular offset cams (520). Device according to the preceding claims, characterized by the fact that the circular or annular plates (14) of the two articulated polygons and the fixed shafts (12) at which are fulcrumed the end rods (11) are mounted on a support plate (19) supported by a stationary element which is integral to the framework of the machine and protrudes on the inside of the wheel (1) between the discs (101) through the tubular shaft (2) supporting one of the discs (101) or by a supporting element connected to the framework of the machine and which radially protrudes into the wheel (1) between the discs (101) from below, that is from a zone of the wheel where no operating station is provided and in where the cavities travel empty, said zone constituting the return route from the discharge station (SC) to the feeding station (SA). Device according to the preceding claims, characterized by the fact that the feeding station (SA) and the discharge station (SC) are arranged diametrically opposed to each other, while the articulated polygons associated with the follower (6) and the pusher (7) are identical to each other and arranged symmetrically in rotation between them relative to the axis of rotation of the wheel (1). Device according to one or more of the preceding claims, characterized by the fact the parallel axis oscillator (2) has one input shaft (220) and two output shafts (120) each for the drive shaft (18, 18') each of the output shafts being dynamically connected to one of the of the two cams (320) supported by the same input shaft (220) by means of a set of rollers (420) on angular offset cams (520). Device according to one or more of the preceding claims, characterized by the fact that the articulated polygons for the follower (6) and the pusher (7) have a radially oriented support rod (8) and which at the opposite extremity corresponding to the follower (6) or pusher (7) is pivoted to a lever (9) which in the median area is articulated to a second end rod (1) which extends itself towards the extremity of the supporting rod (8) associated with the pusher (7) or follower (6) and which is fulcrated to fixed shaft (12) in a freely oscillating manner, which said shaft (12) is integral to a stationary support plate (19), while a further connecting rod (13) is pivoted to the driven oscillating lever (10) and which extends itself in a substantially parallel position to the one of the support rods (8) and of the end rod (11) and the other extremity of which is eccentrically fulcrated (114) to a circular or annular plate (14) revolving around its own axis, like a crank button, as a further oscillating lever (15) is provided which connects in an articulated manner at an intermediate point (108) of the rod (8) which carries the follower or the pusher (6, 7) with an eccentric point of fulcrum of the circular plate or ring (14), in particular coaxial to the eccentric fulcrum (114) of the connecting rod (13). Device according to claim 9, characterized by the fact that the plate (19) can be supported by a stationary element integral to the framework of the machine which protrudes on the inside of the wheel (1) through the tubular shaft (2) supporting the wheel (1, 101) or by a supporting element connected to the framework of the machine which radially protrudes from below into the wheel, that is from a zone of the wheel where no operating station is provided and in where the cavities travel empty, said part constituting the return route from the discharge station (SC) to the feeding station (SA), as the wheel is composed of two discs (101) side by side without mechanical connections between them but are driven in a synchronized manner by a common drive shaft. Device according to one or more of the preceding claims, characterized by the fact that the feeding station (SA) and the discharge station (SC) are arranged diametrically opposed to each other, while the articulated polygons (5) of the follower (6) and pusher (7) are created identical to each other and arranged symmetrically in rotation between them relative to the axis of rotation of the wheel (1). Device according to one or more of the preceding claims, characterized by the fact that an outer envelop forming unit is provided, in particular soft, of a cxigarette packing machine.

Inventors: SPADA VALTER, SPADA, VALTER
Applicants: SASIB SPA, SASIB S.P.A.
Application year: 1997
Main classification: B65B11
IPC codes: B65B11