Transfer device, particularly in packaging machines for cigarettes

Abstract: A transfer device according to the invention comprises a transfer tool (5, 17, 21) which is activated by a rectilinear guide, i.e. by a mechanism made such that a point of attachment (11) of the transfer tool (5, 17, 21) describes a rectilinear trajectory, whereas the drive element (7) is provided with non-rectilinear motion, and in particular with angular motion, which rectilinear guide consists of an articulated multilateral (7, 8, 10; 7, 8, 10, 20), and in particular an articulated quadrilateral or pentalateral. The subject of the invention is also a packaging machine for cigarettes or the like, in which, whenever possible, for each transfer of product into the processing path of the machine, rectilinear transfer units for the products are used, which transfer units are actuated by means of transfer devices activated by articulated multilaterals (7, 8, 10; 7, 8, 10, 20).

Description: This invention relates to a transfer device, particularly in packaging machines for cigarettes, with a transfer tool which is activated by a rectilinear guide, i.e. by a mechanism made such that a point of attachment of the tranfer tool describes a rectilinear trajectory, whereas the drive element is provided with non-rectilinear motion, and in particular with angular motion, which rectilinear guide consists of an articulated multi-lateral. A transfer device of this type is known from the document US-A-1.769.650. In particular, in machine tools which have a plurality of processing units through which the product is passed, for example in packaging machines for cigarettes or the like, in order to guarantee a high output, i.e. a large number of finished products per unit of time, the transfer means have to operate at very high speeds and frequencies, and in a way which is perfectly synchronized with the mechanisms of all the operative units. The various types of rectilinear transfer units currently known are unreliable in terms of both operating speed, and longterm accuracy and consistency of synchronization, so that specific mechanical solutions must be planned according to the various requirements. Often, and in particular in machines for the production and packaging of cigarettes, problems of speed and synchronization are solved by transferring the products along arcuate paths, with the assistance of drums or the like. In addition to extending the path travelled, the means for transferring products along arcuate paths are relatively heavy, and thus give rise to considerable inertia of motion, which necessitates oversized motorization means. Additionally, each transfer unit requires specific transfer means which are specially produced, and in order to obtain longer and more complex paths, a series of successive transfer means may need to be provided. The object of the invention is thus to provide a transfer device of the type initially described, which permits transfer along a rectilinear path, and which, despite a relatively simple structure and lower inertia of motion, permits accuracy of rectilinear movement of the transfer tool within tolerances which are also acceptable for long transfer paths, high frequency of operation, and a high level of adaptability to a wide range of transfer requirements, requiring minimal, inexpensive structural variations. The above-described aims are achieved according to the invention by means of a transfer device of the type initially described, and corresponding to the preamble of claim 1, in which - according to the characterizing part of claim 1 - the articulated multilateral consists of an articulated quadrilateral which comprises two oscillating end arms pivoted around stationary axes, which are parallel to one another, at least one oscillating end drive arm being provided which can be activated, and one oscillation end driven arm which is idle, and the two end drive and driven arms being connected to one another by an intemediate coupling arm, whereas the transfer tool is articulated to the intermediate coupling arm at a point other than the point at which the two end drive and driven arms are articulated to said coupling arm. The invention also relates to other features which further improve the aforementioned transfer device, and which are the subject of the sub-claims. The specific features of the invention and the resulting advantages will become apparent in greater detail from the description of some preferred embodiments, illustrated by way of non-limiting example in the attached drawings, in which: Figs 1 and 2 illustrate schematically a lateral view of a transfer device according to the invention in its configuration in which it can perform alternate movements of advance and return along a rectilinear path, and in particular in the form of a device for transferring rows of cigarettes from a station which forms the rows, into a tubular housing for forming ordered groups of cigarettes in a cigarette packaging machine; Figs 3 to 6 illustrate lateral views in the different end positions of a transfer device according to the invention, which can execute a combined movement according to two components of motion at right angles, and is in the form of a device for transferring an ordered group of cigarettes from the tubular housings of a conveyor with boxes on a guide for transferring the latter to a folding wheel supply station; Figs 7 to 9 illustrate a lateral view in three different positions of a variant embodiment of a transfer device which can execute a combined movement according to two components which are at right angles to one another, in the form of a device for transferring ordered groups of cigarettes along a transfer guide, to a station for supplying a folding wheel of a cigarette packaging machine; Fig. 10 illustrates schematically the operating mechanisms of part of a cigarette packaging machine, in which the rectilinear transfers of the products in the initial processing stages are shown; and Fig. 11 illustrates schematically a plan view of a cigarette packaging machine, with the corresponding path of the products being processed, from the hopper for supplying the cigarettes to the station for supplying the latter to the folding wheel. Figures 1 and 2 illustrate a transfer device according to the invention for transferring rows of cigarettes which are adjacent to one another, from a station 1 for forming the rows beneath a hopper 2, into a tubular housing 3 of a so-called box-type conveyor belt 4. According to this embodiment, the transfer device is made so that a thrust pallet 5 performs an alternate rectilinear movement in the axial direction of the cigarettes, in order to take the row of cigarettes from the formation station 1 into the tubular housing 3. The thrust pallet 5 projects from the end of a tool-holder rod 6. The rod 6 is activated axially by means of an articulated quadrilateral which comprises two oscillating end arms 7 and 8, one of which, a drive arm 7, is attached to a motorized, stationary drive shaft 9, whereas the other driven arm 8, is pivoted such as to oscillate freely around a stationary axis A1 which is parallel to the axis of the drive shaft 9. The end drive arm 7 is connected to the end driven arm 8 by means of an intermediate coupling arm 10, whereas to the latter, at a point of articulation 11 other than those of the end arms 7 and 8, and in particular to an extension 110 of the intermediate coupling arm 10, there is attached the rear end of the tool-holder rod 6. The two end, drive and driven arms 7, 8 are oriented according to straight lines which converge towards one another, i.e. which intersect one another, and the dimensions of the assembly are such that the point of articulation 12 of the drive arm 7 to the intermediate coupling arm 10 passes from one side to the other of the joining line of the drive shaft 9 and the axis 11 of pivoting of the driven arm 8. The drive shaft 9 and the fulcrum axis A1 of the driven arm 8 are disposed on the same side of the rectilinear path of the thrust pallet 5, i.e. of the tool-holder rod 6, the drive shaft 9 being closer to the said rod 6, and offset slightly forwards in the direction of advance of the thrust pallet 5, relative to the axis of pivoting A1 of the driven arm 8. On the side opposite the drive shaft 9, the drive arm 7 has an extension 107, with which it forms part of an associated articulated parallelogram, which consists of a rocker arm 13, which is pivoted such as to rotate idly around a stationary axis A2 which is parallel to the drive shaft 9, which axis passes through the median point of the rocker arm 13. The rocker arm 13 is parallel to the end drive arm 7 with its extension 107, and is connected to the said extension 107 by means of a connection arm 14, which is parallel to the tool-holder rod 6, and with its end on the same side of the said tool-holder rod 6. The opposite end of the rocker arm 13 is articulated to the tool-holder rod 6 by means of a guide arm 15, which is parallel to the extension 110 of the intermediate coupling arm 10, whereas the final element of the articulated parallelogram consists of the tool-holder rod 6 itself. The axis of pivoting A2 of the rocker arm 13 is disposed in a plane parallel to the rectilinear path of the thrust pallet 5, i.e. to the tool-holder rod 6, and which also contains the axis of the drive shaft 9. As is apparent from the figures, the alternate angular motion in one direction or the other of the drive shaft 9 for a predetermined angle, gives rise to movement of the thrust pallet 5 along a rectilinear path, in a direction of advance and return. The dimensions of the arms which constitute the articulated quadrilateral and the articulated parallelogram are such that the assembly has the lowest possible inertial mass. In addition, the ratio between the length of the arms is chosen so as to obtain very low tolerances of deviation from the rectilinear path during advance and return, this being for a path of approximately the length of a cigarette or even slightly longer. When producing a transfer device with a larger or smaller transfer course, and which has similar relative tolerances, it is sufficient to produce a device which has the same geometry as that described above, and in which the length of the arms is increased or decreased in accordance with the ratio between the paths, and such as to maintain the ratio between the length of the individual arms constant. In other words, it is sufficient to produce a device which is similar in the geometric sense of the term, which corresponds to the ratios between the courses. In this condition, the considerable advantage is obtained of having the same angular amplitudes of rotation of the drive shaft 9 for any type of device, thus avoiding adaptation of the drive mechanisms, which can be maintained unchanged. According to a further feature of the transfer device, and as illustrated in Figs 3 to 6, it may be necessary to have a transfer device which has a rectilinear course of advance, and a return course which does not coincide with the course of advance, i.e. a transfer device, the transfer tool of which performs combined movements according to two components of motion which are perpendicular to one another. In this case, according to a first embodiment, it is sufficient to provide drive means for translation of the axis of pivoting A2 of the rocker arm 13, for movement thereof at least along a component which is transverse or perpendicular to the rectilinear motion of advance. Advantageously, in the articulated parallelogram, the rocker arm 13 is disposed in a front position with reference to the advance movement, whereas the articulated quadrilateral is disposed in a rear position. With reference to the example in Figures 3 to 6, at its axis of pivoting A2, the rocker arm 13 is articulated to an oscillating, transverse movement arm 16, which is attached so as to rotate together with the latter, on a motorized drive shaft 16. The drive shaft 16 is connected to motorized rotational drive means 116, which are synchronized with the motorized drive means of the end drive arm 7 of the articulated quadrilateral. The example illustrated in Figures 3 to 6 shows a transfer device, the structure of which is substantially similar to that in Figs 1 and 2, and the parts with the same functions are indicated with the same reference numbers. The said transfer device is shown in the form of a unit for transferring ordered groups of cigarettes from a tubular housing 3 of a conveyor with boxes 14 into a guide 18 for transferring the latter to a station for supplying the ordered group of cigarettes, together with a wrapping sheet, to a so-called folding drum 24 (Fig. 10), by means of which the said sheet is folded around the group of cigarettes. The tool-holder rod 6 supports a transverse thrust plate 17 with a surface which is complementary to the transverse section of the tubular housings 3. The plate is attached to the tool-holder rod 6 by means of a thin bracket 19 which projects at an angle downwards from the end of the tool-holder rod 6, and which during advance movement passes through a slot 103 in the opposite wall of the tubular housing 3. In order to enable the box-type conveyor 4 to advance immediately after the rectilinear movement of transfer of the group of cigarettes from the position in Fig. 6 to the position in Fig. 3, before the angular motion of the drive arm 7 is inverted in order to execute the return course, there is rotated in a synchronized manner the drive arm 16 for transverse movement of the tool 17, which is thus brought into a position which is offset relative to the box-type conveyor 4 (Fig. 4), such that the return course can be executed along a path which does not interfere with the box-type conveyor 4. At the end point of the return end of travel (Fig. 5), the transverse movement arm 16 is activated in the opposite direction, thus realigning the tool 17 on the path of rectilinear movement of transfer, behind the corresponding head side of the new tubular housing 3. However, this solution does not permit execution of transverse movement which is perfectly perpendicular to the rectilinear path of advance of the tool. A solution in which this is possible at least for an initial partial section of the transverse course, according to the perpendicular component of motion, is shown in Figs 7 to 9. In this variant, the articulated multilateral used is an articulated pentalateral which extends from the articulated quadrilateral of the preceding variants, by means of an articulated rod 20 between the intermediate coupling arm and the oscillating end driven arm 8. In addition, in this case also, the tool-holder rod 6 and the end drive arm 7 form part of an articulated parallelogram which is similar to those previously described, but which differs from the latter in that the articulated pentalateral is provided in a front position with reference to the course of advance, relative to the rocker arm 13, which is pivoted such as to oscillate freely around a stationary axis A2, similarly to the examples in Figs 1 and 2. When only one 7 of the oscillating end arms 7, 8 can be activated, the drawing tool 21 performs rectilinear motion of advance and return along the same path. In this case, in order to establish a further component of motion in a direction perpendicular to that of the rectilinear motion of advance, it is sufficient to render mobile also the oscillating end driven arm 8, which thus becomes the motion drive along the perpendicular component. The motorized drive means 22 of the transverse movement oscillating drive arm 8 are independent and synchronized with the drive means 23 of the advance motion drive arm 7. In the example in Figs 7 to 9, the transfer device is used to transfer the group of cigarettes along the rectilinear transfer guides 18, from the end of collection of an ordered group of cigarettes from the box-type conveyor 4, into a station for supplying the said group of cigarettes, together with a first wrapping sheet, into a folding drum 24. The drawing tool 21 is supported such as to project from the front end of the tool-holder rod 6, which, as in the other examples, is parallel to the direction of advance, i.e. to the direction of transfer. The latter has a collection recess 121 for the group of cigarettes, which is superimposed on the latter from above. In the position of the return end of travel (Fig. 7), the drawing tool 21 forms together with the guides 18 a housing which is coaxial to the tubular housings 3 of the box-type conveyor 4 in the station for collection of the group of cigarettes from the housings, and in which the group of cigarettes is transferred from the tubular housing 3 by means of the transfer device according to Figs 3 to 6. In a first stage, only the drive arm 7 of the transfer device is activated, and the drawing tool 21 performs a movement of advance which is rectilinear and parallel to the latter along the guides 18, taking the group of cigarettes into the station for supplying the group of cigarettes to the folding drum 24. In this station, there are provided further mechanisms, not shown in detail, which collect the group of cigarettes and take them into a radial pocket of the folding drum 24. Activation of these mechanisms requires the drawing tool 21 to be moved away from the group of cigarettes, i.e. to be withdrawn from the cigarettes without upsetting the pre-established order of the group. For this purpose, the other transverse movement end drive arm 8 is also activated, so that the drawing tool 21 follows a lifting course according to a path which is perfectly perpendicular to the path of advance, at least for the initial section of disengagement or withdrawal from the group of cigarettes, i.e. substantially corresponding to the height of the latter (Fig. 9). Synchronized and suitably phase-shifted activation in the opposite direction of the two end arms 7 and 8, takes the drawing tool 21 once more into the position shown in Fig. 7, for collection of a new group of cigarettes. Also in the case of the transfer devices according to the examples in Figs 3 to 9, the courses of advance can be adapted by using geometries of the articulated quadrilaterals and parallelograms which are similar to one another in the sense of the geometric definition of the term, corresponding to the ratios of variation of the required courses, and obtaining the same advantage of using similar angular activation movements of the drive arms. The articulated pentagram in the example according to Figs 7 to 9 has the specific feature that the distances from the point of attachment of the tool-holder rod 6 to the intermediate coupling arm, or to its extension 110 and the axes of pivoting A1, of the oscillating end arms 7, 8, are different from one another. In addition, the articulated rod 20 and the intermediate coupling arm 10 together form an angle, the apex of which is always facing substantially outwards. Figs 10 and 11 show schematically part of a cigarette packaging machine, and more specifically that part relating to the specific examples of transfer devices illustrated in the preceding figures. It will be appreciated that the use of rectilinear transfer paths for the products during the processing stage, with the assistance of transfer devices of the type according to the preceding description or the like, can also be extended to subsequent stages and parts of the machine which are not specifically illustrated, to replace any arcuate paths and means for actuating the latter. The transfer devices according to the invention can be used in any type of machine, and in particular in any type of machine tool which is provided with a plurality of processing units which operate alternately, and which require high operating speeds and a high level of accuracy and long-term consistency of reciprocal synchronization of the equipment.

Claims: Transfer device particularly in packaging machines for cigarettes, with a transfer tool (5, 17, 21) which is activated by a rectilinear guide, i.e. by a mechanism made such that a point of attachment (11) of the transfer tool (5, 17, 21) describes a rectilinear trajectory, whereas the drive element (7) is provided with non-rectilinear motion, and in particular with angular motion, which rectilinear guide consists of an articulated multilateral (7, 8, 10; 7, 8, 10, 20), characterized in that the articulated multilateral consists of an articulated quadrilateral which comprises two oscillating end arms (7, 8) pivoted around stationary axes (A1, 9), which are parallel to one another, at least one oscillating end drive arm (7) being provided which can be activated, and one oscillating end driven arm (8) which is idle, and the two end drive and driven arms (7, 8) being connected to one another by an intermediate coupling arm (10), whereas the transfer tool (5, 17, 21) is articulated to the intermediate coupling arm at a point (11) other than the points at which the two end drive and driven arms are articulated to said coupling arm. Device according to Claim 1, characterized in that the transfer tool (5, 17, 21), or a tool-holder rod (6) is articulated (11) to an extension (110) of the intermediate coupling arm (10). Device according to Claim 2, characterized in that the extension (110) of articulation to the tool-holder rod (6) or to the tool (5, 17, 21) is on the side opposite the end driven arm (8) relative to the point of articulation (12) of the drive arm (7) to the intermediate coupling arm (10). Device according to one of the preceding claims, characterized in that the oscillating drive and driven end arms (7, 8) are oriented in directions which are divergent from or convergent towards one another. Device according to one of the preceding claims, characterized in that the geometry of the articulated quadrilateral is such that the point of articulation (12) of the end driven arm (7) to the intermediate coupling arm (10) passes from one side to the other of the joining line of the stationary axes of pivoting (A1, 9) of the two end drive and driven arms (7, 8), from one to the other of the two extreme end of travel positions. Device according to Claim 1, characterized in that the articulated multilateral consists of an articulated pentalateral which extends from an articulated quadrilateral according to one or more of the preceding claims, the end driven arm (8) being articulated to the intermediate coupling arm (10) by means of a further articulated rod (20). Device according to Claim 6, characterized in that the geometry of the articulated pentalateral (7, 8, 10, 20) is such that the distances between the point of attachment (11) of the tool (21) or of the tool-holder rod (6) to the extension (110) of the intermediate coupling arm (10) and the axes of pivoting (A1, 9) of the oscillating end drive and driven arms (7, 8), are different from one another. Device according to Claim 6 or Claim 7, characterized in that the geometry of the articulated pentalateral is such that the intermediate coupling arm (10) and the articulated rod (20) form between one another an angle, the vertex of which is always oriented outwards from the articulated pentalateral. Device according to one of the preceding claims, characterized in that the articulated multilateral, together with the end drive arm (7), the intermediate coupling arm (10) or their extensions (107, 110), and the tool-holder rod (6), forms part of an articulated parallelogram (7, 107, 10, 110, 6, 13, 14, 15). Device according to Claim 9, characterized in that the articulated parallelogram consists of the end drive arm (7) with an extension (107) thereof on the side opposite the intermediate coupling arm (10), of the intermediate coupling arm (10) with an extension (110) thereof beyond the point of articulation (12) to the end drive arm (7), both arms (7, 10) forming part of the articulated multilateral, of the tool-holder rod (6), and of a rocker arm (13) which is parallel to the end drive arm (7) and is pivoted so as to oscillate freely around a transverse median axis (A2) thereof which is parallel to the axis of pivoting of the drive arm (7), which rocker arm (13) is articulated on the one side to a connection arm (14) which is articulated to the drive arm (7), or to its extension (107), and on the other side is connected to the tool, i.e. to the tool-holder rod (6), by means of a guide arm (15). Device according to Claim 10, characterized in that the articulated quadrilateral is disposed in a rear position relative to the axis of pivoting (A2) of the rocker arm (13) with reference to the course of advance. Device according to claim 10 or 11, characterized in that means are provided which can be activated in a manner synchronized to the drive arm (7) of the articulated quadrilateral, and which move transversely, and in particular perpendicularly, to the rectilinear path of advance of the axis of pivoting (A2) of the rocker arm (13). Device according to Claim 12, characterized in that at the axis of pivoting (A2), the rocker arm is articulated to a transverse movement drive arm (16) which can be activated, which arm is attached to a drive shaft for angular drive means (116), which are synchronized with the angular drive means of the drive arm (7) of the articulated quadrilateral. Device according to Claim 10, characterized in that the articulated pentalateral is disposed in a front position relative to the axis of pivoting (A2) of the rocker arm (13), with reference to the rectilinear course of advance. Device according to Claim 14, characterized in that Claim 16, characterized in that means (8, 22) are provided for imparting to the tool (21) a further component of motion in a direction perpendicular to the rectilinear path of advance. Device according to Claim 15, characterized in that the means for moving the tool (21) according to the further perpendicular component, consist of the end driven arm (8) which can also be activated and synchronized with the drive arm (7), the said end driven arm (8) being pivoted on a drive shaft which can be moved angularly by motorized means (22). Device according to one of the preceding claims, characterized in that the axis of the drive shaft (9) of the drive arm (7) for rectilinear advance motion, is laterally offset adjacent to the plane in which the rectilinear path is provided, whereas the axis (A1) of pivoting of the end driven arm (8) is provided on the same side of the rectilinear path as the axis of the drive shaft (9), but at a greater distance and slightly offset rearwards, with reference to the course of advance. Device according to one of the preceding claims, characterized in that, at least along the course of advance, the axis of the drive shaft (9) and the axis of pivoting (A2) of the rocker arm define a plane which is parallel to the rectilinear path of advance. Device according to one of the preceding claims, characterized in that variations in the rectilinear maximum course of advance are obtained by maintaining the angles of activation of the drive shaft (7) and of the means (16, 116, 8, 22) of transverse movement of the tool constant, and by using articulated multilaterals and associated articulated parallelograms which are similar according to the geometric meaning of the term, corresponding to the ratio of variation of the maximum course of advance.

Inventors: DI CAMILLO ORAZIO, SPADA WALTER, DI CAMILLO, ORAZIO, SPADA, WALTER
Applicants: SASIB TOBACCO SPA, SASIB TOBACCO S.P.A.
Application year: 1995
Main classification: B65B65
IPC codes: F16H21, B65B65