1 A device for supplying products arranged in series to a-successive work
station is ?0
The present invention relates to a device by means of which products arranged in series are fed to a successive work station. Such a device can be utilized advantageously, for example, to supply rolls of material to a wrapping machine, or containers of cigarettes to a packaging machine. The art field of automatic machines, and especially of machines by which commodities are wrapped in material uncoiled from rolls, embraces the use of magazine loaders capable of carrying a plurality of rolls of the wrapping material and supplying them automatically to a successive work station. Considering, by way of example, a magazine of the type conventionally used for such rolls of wrapping material, the single rolls are ordered in series one beside the next, coaxial one with another and forming an unbroken row or column extending along a continuous conveyor that consists, for example, in a pair of belt loops.
2 In effect, the conveyor belts establish a cradle by and along which the rolls are supported and indexed prior to their passage singly and in succession to the work station. The particular characteristic required of magazines of the type in question is that at least one roll of wrapping material should be available at any given moment for pick-up by the loading device of the work station. Clearly enough, this level of availability cannot altogether be ensured by such a cradle structure; not only do the conveyor belts lack the strength necessary to meet any given operating requirement, but also, their lack of perfect rigidity occasions elongation and the tendency to sag, with the result that the header roll is distanced from the loading device of the work station and angled marginally away from the nominal axis of coaxiality of the entire column of rolls, which would lie parallel to the axis of an undistorted belt cradle. The importance of maintaining coaxial alignment of the rolls is considerable, as the loading device will be provided normally with a swing arm capable of rotating about and reciprocating along an axis disposed parallel to the axis of coaxial alignment 3 in question. The arm is provided at one end with a shank designed to engage an axial bore afforded by the core of the roll,' and thus lift and transfer the roll from the belts to the work station served by the magazine. To effect the pick-up of a roll, the arm is positioned in readiness with its shank coaxial to the nominal axis of coaxiality of the rolls, before approaching in such a way that the shank locates in the core of the header roll. Naturally enough, if the belts sag and cause the rolls to drop out of coaxial alignment, the shank of the swing arm will fail to insert into the core and instead impinge on the wound material, with the result that the material itself may be damaged and the inability of the arm to effect a pick-up will trigger shut-down of the machine. The simplest method of reducing the tendency of the belts to sag is to increase their rigidity through the addition of fixed supports. The type of support which offers best results from the point of view of increasing rigidity consists in a rectilinear guide, for example a longitudinal member, positioned beneath each of the belts. Such an arrangement can be adopted only where products of substantially lightweight embodiment are to be 4 conveyed, however, otherwise the coefficient of friction between support and belt might reach such high values as to occasion early wear on the belts and an inordinately high requirement in respect of the energy needed for their propulsion. The problem is aggravated further by the fact that the conveying surfaces of the belts are disposed not within a common plane, but rather, angled in relation to one another so as to form the cradle. In this instance, each longitudinal members must also be offered to one edge of the relative belt, with the result that the coefficient of friction between support and belt is increased yet further. One method of reducing friction might be to support the belts on a bank of freely revolving rollers, although the rigidity of the belts would also be reduced in this instance. Given that the loads to be supported and conveyed are not inconsiderable, the transverse dimensions of the pivots carrying the freely revolving rollers, hence of the rollers themselves, naturally must be of a certain order to ensure adequate mechanical strength. Consequently, the distance between successive rollers might again be sufficient to allow the belt to sag, upsetting the coaxial alignment of the rolls and giving rise 'Y is to the problems already described above. Besides failing to overcome the difficulties in question, moreover, the solutions mentioned thus far involve considerable costs, to the extent of rendering the magazine over- expensive. Accordingly, the object of the invention is to provide a device capable of performing the function of a magazine in correct fashion, i.e. of ensuring the constant availability of a roll of continuous strip wrapping material or of whatever product in general, facing in a prescribed direction, for transfer to a successive work station. The stated object is realized, according to the invention, in a device by which products arranged in series such as rolls of material in a wrapping machine, or containers of cigarettes in a cigarette packaging machine, are supplied to a successive work station in readiness for pick- up by a loading device associated with the station, characterized in that it comprises: -rigid, fixed means affording static support to the products; -means designed to lift and feed the products along the lengthwise direction of the rigid and fixed static support means, parts of which at least are 6 destined to enter into contact with the products and capable of movement through a looped trajectory defined by at least four successive positions: a at rest, occupying a level lower than that of the static support means and retracted from the loading device of the work station, in which the products rest exclusively on the static support means; a contact, occupying a level higher than that of the at-rest position, in which the products are supported exclusively by the lift and feed means and distanced from the static support means; a transfer, in which the column is indexed forward and the leading product, considered in relation to the feed direction, lies in close proximity to the loading device; a release, in which the products are replaced on the static support means and the leading product of the column lies within reach of and in readiness for pick-up by the loading device; and in that the lift and feed means move from the contact to the transfer position while supporting the products, whereas movement from the release to the at-rest position is effected with the products distanced from the lift and feed means and resting on the static support means.
7 The invention will now be described in detail, by way of example, with the aid of the accompanying drawings, in which: -fig 1 shows a perspective of the device according to the present invention, from which certain parts are omitted and certain cut away better to reveal others; - fig 2 is a side elevation of the device of fig 1, from which certain parts are omitted and certain cut away better to reveal others; -fig 2a is a side elevation of detail A in fig 2; -fig 3 affords a frontal elevation of the device of fig 1; -fig 4 is a frontal elevation of a device similar to that of fig 1, structured for the handling of products dissimilar to those of fig 1; -fig 5 illustrates an alternative embodiment of detail A in fig 2, viewed in side elevation. With reference to fig 1 of the drawings, 1 denotes a device according to the present invention, by means of which to supply products 3 to a successive work station, denoted 17 in its entirety, of which 33 denotes a pick-up and transfer arm 33 that is conventional in embodiment and thus described no further. The products 3, which in the example of 8 fig 1 consist in rolls 3 of wrapping or packaging material, are arranged in series one alongside the other in such a way as to form a column denoted 6. The device 1 comprises means 4 of fixed and rigid embodiment affording static support to the column 6 of products 3, and lift and feed means 5 by which the line is raised and indexed forward. It will be observed from figs 2 and 3, that the feed means 5 are embodied as a self- contained unit, and mechanically independent of the static support means 4. The static support means 4 consist essentially in a pair of straight horizontal beams 7 lying mutually parallel and associated with a fixed bed 8. 18 denotes a plurality of brackets associated with the beams 7 (see fig 1) and providing mounts for a pair of restraint rails 19 disposed parallel with and above the respective beams 7. 1 As discernible from figs 1, 2 and 3, the beams 7 and restraint rails 19 combine in effect to create a fixed cradle such as will support and contain the column 6 of rolls 3. The lift and feed means 5 comprise a pair of bars 9 disposed parallel with and between the beams 7 and interconnected by cross members 20, thus affording 9 a frame of ladder-like appearance. The bars 9 are associated with support and propulsion means 10 by which the ladder frame is carried and manoeuvred through a looped trajectory incorporating at least four positions, as will be described in due course. In the case of the embodiment illustrated, the propulsion means 10 consist in a slide 11, capable of movement along a pair of guide rods 12 disposed parallel to the beams 7, and a pair of shafts 13 disposed transversely to the rods 12; the two guide rods 12, singly denoted 12a and 12b, are anchored at each end to the bed 8. The slide 11 and the bed 8 are interconnected by actuator means 15 embodied in the example of figs 1 and 2 as a fluid power cylinder 25, by which the slide 11 is shuttled along the rods 12 between two limit positions in the direction denoted FA (see fig 2). The slide 11 consists essentially in a pair of hollow cylindrical members 29 and 30 slidable axially along the guide rods 12'and interconnected by a pair of cross pieces 31. The shafts 13 are supported by the slide 11 and rotatable about their respective longitudinal axes (see fig 1, which shows the shafts 13 freely and rotatably inserted through corresponding lugs 32 is afforded by the two cylindrical members 29 and 30) and capable thus of being set in notion by relative actuator means 14. 21 denotes an arm rigidly associated by one end with each of the shafts 13 and projecting downward between the two cylindrical members 29 and 30; the proecting ends of the arms 21 are linked together pivotably by a tie-rod 22 in such a way that the two shafts 13 can be rotated as one. In the example shown in the drawings, the actuator means 14 are embodied as a fluid power cylinder 23 anchored to a cross member 34 of the slide 11 and impinging on one of the two arms 21 in such a way as to permit of rotating the two shafts 13 together at one and the same time and in either direction (arrow FR, fig 2 a). 24 denotes a pin projecting from each end of each shaft 13, disposed parallel with but offset from the axis of the shaft and inserted freely into the relative bar 9 (see figs 2, 2a and 5, in which the pin 24 is shown associated with a radial arm 35 extending from the shaft 13). Thus, by rotating the shafts 13, the bars 9 can be raised or lowered between two limit positions of dissimilar height (arrow FS, figs 2a and 5).
m 11 The bearing surface afforded by the beams 7 lies at a height above that afforded by the bars 9 when the latter are in the lowered limit position, whereupon rotation of the shafts 13 and consequent movement of the bars 9 to the raised limit position has the effect of lifting the rolls 3 and distancing them from the beams 7. The fluid power cylinders 23 and 25 are interlocked to automatic control means (not illustrated) and kept in a normally at-rest position whereby the slide 11 is distanced from the loading device 2 and the bars 9 are distanced from the rolls 3, so that the column 6 is cradled entirely and exclusively by the beams 7 and the restraint rails 19. During operation of the device 1, the bars 9 are cycled through a looped trajectory characterized by at least four positions: at-rest, contact, transfer and release, respectively, which coincide with the extension and retraction of the actuator means 14 and 15, as will shortly become clear. Departing from the at-rest configuration of the device 1, the cylinder denoted 23 is activated to rotate the shafts 13 (arrow FR, fig 2a) and lift the bars 9 to their raised limit position (phantom line 91 of fig 2a), thus achieving the position of 12 contact. In rising, more exactly, the bars 9 enter into contact with the rolls 3, lifting them from the beams 7 and rails 19 as illustrated in fig 3, where the raised position of the rolls is shown by the phantom line denoted 3f. Thereafter, with the rolls 3 supported exclusively by the bars 9, the remaining cylinder 25 is activated to direct the slide 11, and with it the rolls 3, closer to the collection device 2 (arrow FA, fig 2); this is the transfer configuration of the device, in which the slide 11 occupies an extended position illustrated in fig 2 by the phantom line denoted ill. With the slide 11 fully forward, the first cylinder 23 is again activated to rotate the shafts 13, this time in the opposite direction (arrow FR, fig 2a), thus lowering the bars 9 (arrow FS, fig 2a) and bringing the device to the release configuration. With the bars 9 lowered, the rolls 3 come to rest once again on the beams 7 and the restraint rails 19. Finally, the second cylinder 25 is activated to return the slide 11 to the original retracted position (arrow FA, fig 2), distanced from the loading device 2 of the work station. At this point, the device has regained the at-rest position as before.
c 13 is The advantages of a device according to the present invention will be evident. In effect, by adopting an independent embodiment of the means by which the rolls 3 are respectively supported and indexed, each can be structured in the manner best suited to a correct implementation of the designated task. For example, the beams 7 and rails 19 serve solely to provide a substantially permanent support for the rolls 3, and therefore can be embodied with a particularly strong and rigid structure cap.able of bearing considerable weight essentially without flexing. By contrast, the structure of the feed means 5 will be sufficiently robust to support the rolls 3 for a brief interval while bringing about their movement through a rectilinear direction. In each operating cycle, the bars 9 are displaced through a given travel L in one direction and then returned in the opposite direction through the identical distance L to their initial position; accordingly, by ensuring that this travel L is not less than the width S of the roll 3, as measured along the direction of movement of the slide 11, the column 6 can be compressed marginally against the loading device 2 to facilitate a more secure pick-up.
14 Given that the rotational movement of the shafts 13 causes the bars 9 to describe a circular arc, i.e. shifting not only in the vertical direction but also a short distance through the horizontal, the distance L travelled by the slide 11 can be matched to the width S of the single roll 3 of material, the horizontal movement of the descending bars 9 being directed toward the loading device 2. In the event that the products being handled are of different shape, for example parallelepiped as in the case of containers filled with cigarettes ready for packaging (fig 4), the geometry of the support means 4, and even of the feed means 5, might be different to that illustrated in fig 1 in order to guide and restrain the products to better effect. Accordingly, the beams 7 and bars 9 of the device shown in fig 4 are substantially vertical, rather than angled and convergent as in figs 1 and 3. Fig 5 illustrates an alternative embodiment of the detail denoted A in fig 2, in which the pins 24 of the rotatable shafts 13 are slidably accommodated in longitudinal slots 26 afforded by the bars 9 and the bars 9 in their turn are associated with the slide 11 by way of vertical guide means 16. Such guide means 16 appear in fig 5 as vertical posts 27 1 c i is rigidly associated with the bars 9, accommodated by and axially slidable within respective sockets 28 afforded by the slide 11. With an arrangement of this type, the movement of the bars 9 produced by rotation of the shafts 13 can be kept within the vertical axis, such that the longitudinal distance indexed by the column of rolls 3 with each cycle is dependent exclusively on the travel L accomplished by the slide 11. In an alternative embodiment of the device, the travel of the slide 11 might be varied readily, and with greater continuity, by adopting a motor driven lead screw in place of the fluid power cylinder 25. Likewise in an alternative embodiment, at least one of the beams 7 could be associated with the fixed bed 8 in such a way as to allow freedom of parallel movement, thus enabling its adjustment for position to suit the diameter of the rolls 3 being handled; similarly, at least one of the two bars 9 might be adjustable in relation to the slide 11.
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