Equipment for transferring rod-like articles

Technical Field The present invention relates to equipment for transferring rod-like articles, such as cigarette filters, by way of example. More particularly, the invention relates to an item of equipment for transferring filters from an in-line storage unit, located at the outfeed stage of a filter maker, to the mouth of a pneumatic feed duct connected to a feed hopper forming part of a filter tip attachment machine.

Background Art The prior art embraces equipment, as disclosed for example in US 3,827,757, comprising a magazine filled with a mass of filters stacked horizontally alongside one another; the filters are transferred singly to the mouth of the pneumatic feed duct, from where each one is propelled along the duct in a direction parallel to its own axis. The aforementioned transfer of the filters from the bottom end of the magazine to the mouth of the duct is effected typically by means comprising a drum rotatable about a horizontal axis, disposed parallel to the axes of the single filters, and affording peripheral aspirating flutes extending parallel to the axis of rotation, each able to accommodate a single filter. The filters drop by gravity from the magazine into the flutes of the drum, and after rotating on the periphery through 180°, or thereabouts, are brought singly and in succession into a transfer station where each one in turn is invested by a flow of compressed air and directed thus along the pneumatic duct toward the filter tip attachment machine. The equipment disclosed in US 3,827,757 further comprises a sealing block interfaced with a bottom portion of the drum and presenting a cylindrically concave surface matched to the cylindrical surface of the selfsame drum. The sealing block is capable of vertical motion between a raised first position substantially in contact with the cylindrical surface of the drum, enclosing the flutes of the drum when the equipment is in operation, and a lowered second position, distanced from the drum in order to enable routine cleaning, or other servicing operations such as the removal of a blockage that can occur when a filter sticks fast in one of the flutes of the drum or in the mouth of the pneumatic duct. It has been found that with certain types of blockage, however, in particular when the filters are inserted completely or almost completely in the mouth of the duct, it can be especially difficult to remove the filters, even when the sealing block is distanced from the transfer station. The object of the present invention is to provide equipment for the transfer of rod-like articles, typically filters for cigarettes, such as will be unaffected by the drawbacks in question and will also be of simple and straightforward embodiment.

Disclosure of the Invention The stated object is realized according to the present invention in equipment for transferring rod- like articles, typically cigarette filters, of which the characterizing features are as recited in claim 1 appended. The invention will now be described in detail, by way of example, with the aid of the accompanying drawings, in which: -figure 1 illustrates equipment for transferring filters, embodied in accordance with the present invention, viewed schematically in elevation with parts in section and shown in a first operating position; -figures 2 and 3 show the equipment of figure 1 in two further and different operating positions; -figure 4 shows a detail of figure 1, illustrated schematically and in perspective, in an exploded view; -figure 5 shows the equipment of figure 1 viewed from letter F, schematically and in elevation, with certain parts omitted better to reveal others; -figures 6 and 7 show the detail of figure 4 in a plan view, illustrated schematically and in two operating positions corresponding to figure 1 and figure 2. With reference to figure 1 and figure 5 of the drawings, 1 denotes equipment, in its entirety, by which rod-like articles 2 consisting in filters for cigarettes are transferred from dispensing means 3 to a user machine represented schematically by a block 4 and consisting in a filter tip attachment machine, by way of a pneumatic feed duct 5. The dispensing means 3 in question comprise a hopper 6 with front and rear walls denoted 7 and 8, respectively, interconnected by two side walls 9 and 10. The filters 2 are stacked transversely to the side walls 7 and 8 of the hopper 6, which is enclosed at the bottom by a drum 11 set in rotation about an axis 12 extending transversely to the side walls 7 and 8 and furnished peripherally with a plurality of aspirating axial flutes 13, each able to accommodate a single filter 2. As illustrated also in figure 4, the equipment 1 further comprises a body 14 of elongated appearance located beneath the drum 11, diametrically opposed to the hopper 6 and aligned on an axis A parallel to the axis 12 of rotation, of which the bottom presents a flat horizontal surface 15 and the sides present two vertical surfaces 16 parallel with the axis A, whilst the opposite ends present a vertical rear face denoted 17 and a vertical front face denoted 18. The body 14 presents a first portion, or sealing block 19, positioned directly beneath the drum 11, and a second portion 20 extending beyond the right end face 21 of the drum 11, as viewed in figures 1 and 4, in the direction followed by the pneumatic feed duct 5. The aforementioned sealing block 19 is delimited uppermost by a cylindrically concave surface 22 breasted with and matched to the cylindrical face of the drum 11 in such a way as to function as a radial closure element masking all the flutes 13 compassed by an arc denoted 23 (see figure 4) . The second portion 20 is delimited uppermost by a flat horizontal surface 24 and, at the end offered to the drum 11, by a vertical surface 25 adjoining the concave surface 22; observing figures 1 and 4, this same surface 25 is breasted substantially in contact with a lower portion 26 of the right end face 21 presented by the drum 11. In particular, the concave surface 22 affords an element by means of which to enclose and seal the lower part of the drum 11 at a transfer station 27 into which the single filters 2 are directed by the drum 11, preferably indexing in rotation, and from which each one is ejected pneumatically into the feed duct 5 when the relative flute 13 occupies the station 27, by way of an inlet portion 28 in the form of a channel 29 incorporated into the second portion 20 and aligned axially with the flute 13. In particular, the channel 29 afforded by the second portion 20 of the body 14 coincides with a movable portion 29 of the pneumatic feed duct 5 and functions, in the operating position of figure 1, as an inlet portion 28 connecting a flute 13 of the drum 11 with a fixed portion 5a of the pneumatic feed duct 5. As illustrated in figures 4, 6 and 7, the body 14 is mounted together with interposed sliding means denoted 30 in their entirety, and capable thus of reciprocating motion parallel with the axis A, to support means denoted 31 in their entirety, which in turn are capable of vertical movement between two limit positions illustrated in figures 1 and 3. More precisely, the sliding means 30 comprise a slide 32 fixed to the underside of the body 14, and two slide rails 33 extending parallel to the axis A of the selfsame body and secured at the opposite ends to the support means 31. The slide 32 appears substantially rectangular in shape, with a predominating dimension that extends parallel to the axis A of the body 14, and presents two transverse blocks 34a and 34b, each affording a pair of clearance holes 35 to receive the rails 33. The two blocks 34a and 34b are interconnected by a web 36. The support means 31 comprise a skeleton frame 37 of substantially elongated rectangular appearance, consisting essentially of two longitudinal bars 38 extending parallel to the axis A and interconnected by two transverse bars 39a and 39b, one at either end, to which the opposite ends of the two slide rails 33 are anchored. The support means 31 further comprise a vertical shaft 40, capable of reciprocating movement induced by actuator means illustrated schematically as a block 41, which is inserted through a slot 42 in the web 36 of the slide 32 and secured at the top end to an intermediate transverse bar 43 of the frame 37. The intermediate transverse bar 43 is extended externally beyond the longitudinal bars 38 to form two lugs 44 affording respective bushes 45 slidably accommodating two vertical guide rods 46 parallel to the vertical shaft 40 (see figures 5, 6 and 7) . By virtue of the arrangement described above, the actuator means 41 are able to translate the body 14 in a vertical direction toward and away from the drum 11 (see figures 1 and 3, respectively), while the body 14 itself remains free to slide parallel with the axis A. Located between the transverse bar 39a on the left, as seen in figures 4, 6 and 7, and the corresponding block 34a of the slide, are spring means 47 embodied as compression coil springs 48 ensheathing the slide rails 33 and able thus to exert a pushing force on the slide 32, hence on the body 14, directed from left to right as seen in figure 1. Also forming part of the equipment is a coupling portion 49 positioned immediately downstream of the aforementioned second portion 20 and establishing a pneumatic connection between the movable channel 29 afforded by the second portion 20 of the body 14 and the fixed portion 5a of the duct 5, whenever the channel 29 occupies the position of figure 1 in which it serves as an inlet portion of the feed duct 5. The coupling portion 49 is rendered capable of axial movement along the axis A of the body 14, and in particular, slidable on a tubular element 50 incorporating the mouth of the fixed portion 5a and inserted into the selfsame coupling portion 49. The aforementioned axial movement is induced by respective actuator means 51, shown as a block, and occurs between two limit positions of which one, illustrated in figure 1, is a position of air-tight contact between the coupling portion 49 and the transverse front face 18 presented by the second portion 20 of the body 14; in the other position, illustrated in figure 2, the coupling portion 49 is distanced from the transverse front face 18 and the pneumatic continuity of the feed duct 5 therefore broken. Observing figures 2 and 7, it will be seen that the separation of the coupling portion 49 from the transverse front face 18 occurs when the slide 32, loaded against the spring 48, registers against a stop element 52 projecting toward the block 34b from the corresponding bar 39b of the frame 37. In operation, filters 2 descending by gravity from the hopper 6 are taken up by the flutes 13 of the drum 11, which rotates intermittently in an anticlockwise direction as viewed in figure 4, and conveyed singly into the transfer station 27 where each is brought to a halt in alignment with the outlet port 53 of a duct 54 connected to a source of compressed air 55. With reference to figure 1, and assuming normal operation of the transfer equipment 1, the single filters 2 are propelled pneumatically from the flute 13 along the feed duct 5, passing through the channel 29, the coupling portion 49 and the fixed portion 5a of the duct 5, thence toward the filter tip attachment 4. In the event of a blockage occurring, for example as the result of a filter 2 lodging completely or partially in the mouth of the feed duct 5 and thus internally of the channel 29, the operator will be able to remove the impediment from the equipment 1, in view of the configuration described above, by performing the following succession of steps. Starting from the situation of normal operation illustrated in figure 1, hence with the movable portion 29 and a flute 13 of the drum 11 connected one to another, the coupling portion 49 is caused by the actuator means 51 to shift away from the drum 11 by sliding on the tubular element 50. During a first stage of this sliding movement, the body 14 shifts under the force of the spring means 47 and follows the coupling portion 49, with which the transverse front face 18 initially stays in contact, causing the surface 25 of the second portion 20 to separate from the corresponding end face 21 of the drum 11 . As the surface 25 of the second portion 20 is distanced from the end face 21 of the drum 11, the movable portion 29 separates from the flute 13 of the drum 11, with the result that the pneumatic continuity of the feed duct 5 is broken. During a second stage of the sliding movement, after the body 14 has reached its travel limit and caused the block 34b of the slide 32 to register against the stop element 52, the transverse front face 18 of the body 14 separates from the coupling portion 49 as illustrated in figure 2. In this situation, the body 14 is rendered free of constraints and can be directed by the relative actuator means 41 into the position of figure 3. The position now occupied by the channel 29 is such that the ends are left free and accessible, allowing the operator to carry out any necessary maintenance work, for example with the aid of pneumatic or mechanical tools. Importantly, this same step of distancing the body 14 from the transfer station 27 facilitates the removal of filters that may jam between the movable channel 29 and the mouth of the coupling portion 49.