EP1883319B1

EP1883319B1 - A unit for transferring sticks of rod material used to manufacture tobacco products

Info

Publication number: EP1883319B1
Application number: EP06744503A
Authority: EP
Inventors: Marco Esposti; Fiorenzo Draghetti
Original assignee: GD SpA
Current assignee: GD SpA
Priority date: 2005-04-19
Filing date: 2006-04-18
Publication date: 2009-06-17
Anticipated expiration: 2026-04-18
Also published as: CN101287385A; WO2006111814A3; DE602006007341D1; EP1883319A2; ATE433677T1; WO2006111814A2; ITBO20050252A1; CN101287385B

Abstract

Sticks of rod material used in the manufacture of tobacco products are transferred from one machine to another by a unit comprising two parallel feed channels (2a, 2b) spaced apart at a set pitch (p) , along which two lines of sticks (S) emerge from a dual rod maker, and a drum (3) rotatable about an axis (X) parallel to the feed channels (2a, 2b) , of which the revolving surface affords a succession of flutes (4) alignable in pairs with the two feed channels (2a, 2b) and positionable thus to take up the respective sticks (S) of rod material from the two feed channels (2a, 2b) . Each flute (4) of the drum (3) is separated from the adjacent flute by a distance less than the pitch (p) between the two feed channels (2a, 2b) .

Description

Technical Field

The present invention relates to a unit for transferring sticks of rod material used in the manufacture of tobacco products.
A stick of rod material, where referred to in the following specification, can be taken to mean any given element of elongated cylindrical appearance as used in the manufacture of tobacco products. The sticks in question could be cigarette sticks, for example, turned out by a dual rod type of cigarette making machine designed to generate two successions of cigarette rods, simultaneously and in parallel, which are cut subsequently by suitable devices into discrete lengths. Alternatively, the rods might be rods of filter material.

Background Art

In a system for manufacturing tobacco products, whatever the particular type of rod material from which the sticks are cut, these same sticks must be released from the machine on which they are made and transferred to another machine. Thus, by way of example, cigarette sticks produced by a dual rod cigarette maker, and likewise filter plugs cut from a rod, are transferred to a filter tip attachment machine that will proceed to assemble one double length filter plug with two cigarette sticks.
In the art field of systems for the manufacture of tobacco products, accordingly, the prior art embraces units by means of which to transfer sticks of rod material from one machine to another, see e.g. EP-A-0682881 .
A first conventional type of transfer unit takes the form of a rotating platform furnished with a plurality of arms, each equipped at the outer end with a gripper mechanism such as will take up two cigarette sticks emerging side by side from the dual rod cigarette maker and transfer them to the next machine. The sticks thus transferred are kept parallel one with another and carried through an angle of 90° along a path describing an arc to a circle, to a position where they can be placed in flutes afforded by an infeed roller serving the filter tip attachment machine.
Whilst extremely efficient and reliable, transfer units of this type are somewhat costly, difficult to implement and complicated to set up.
Moreover, given the very high output capacity of modern machines used in the manufacture of tobacco products (16,000 - 18,000 cigarettes per minute or thereabouts), the type of transfer unit in question will not always be able to handle a sufficiently high number of sticks per unit of time.
The prior art also embraces a second type of transfer unit, designed specifically to overcome the drawbacks mentioned above.
This transfer unit consists substantially in a drum, rotatable about an axis parallel to the feed direction followed by the sticks of rod material and presenting a succession of peripheral flutes by which the sticks are taken up seriatim and conveyed toward the filter tip attachment machine.
More precisely, the rotating drum is positioned momentarily with two adjacent and successive flutes aligned on the outfeed point at which the sticks of rod material emerge from the dual rod maker. Two sticks are directed into the two flutes without any pause in the rotation of the drum, and another two mutually adjacent flutes next in sequence to the flutes filled previously are brought into alignment with the outfeed point of the dual rod maker. Given the high transfer speeds expected of the unit, and the need for compactness, the drum must necessarily rotate at high angular velocities.
Since high angular velocities tend to damage the sticks of rod material entering the flutes of the drum (due to the notable difference in transverse velocity between flute and stick), the drum of the transfer unit is equipped with an impeller device serving to transmit a transverse velocity component to the sticks. The impeller device also performs a function of distancing each pair of sticks leaving the dual rod maker from the next pair in sequence, by inducing a longitudinal acceleration in the pair passing onto the drum. More exactly, the impeller device is embodied as a roller, rotatable about an axis normal to the feed direction followed by the sticks of rod material and furnished with a helical groove extending the full length of its developable periphery. As the roller turns, the helical groove engages the successive pairs of sticks, investing them with a transverse velocity component and with a longitudinal acceleration component so as to ease their passage into the flutes of the drum.
Nonetheless, even when equipped with the impeller roller, the drum cannot always be made to rotate at the requisite angular velocities.
In effect, the higher the rotational speed of the drum, and consequently the greater the centripetal acceleration on the sticks of rod material, the more difficult it becomes to retain the sticks in the flutes.
Furthermore, the transverse velocity components induced by the impeller roller in the transferred sticks can lead in extreme cases to the stick being broken, or in any event damaged, as a result of the excessive stresses in play.
Another significant drawback stems from the fact that a change in the type of sticks being handled, for instance involving a change in the length of the single stick, dictates that the impeller roller likewise must be changed, and a different speed of rotation selected for the replacement roller. In practice, if the stick of rod material is increased in length, then the helical groove of the impeller roller will no longer be able to complete the step of guiding a pair of sticks into two corresponding adjacent and consecutive flutes of the revolving drum before the next pair of flutes has begun to draw into alignment with the impeller roller, and the sticks of rod material will be destroyed.
In this context, the main purpose of the present invention is to set forth a unit for transferring sticks of rod material used in the manufacture of tobacco products, such as will be unaffected by the drawbacks mentioned above.
More particularly, the object of the invention is to provide a unit for transferring sticks of rod material used in manufacturing tobacco products, capable of operating at high transfer speeds.
A further object of the invention is to provide a transfer unit of which the operating capacity will remain independent of the dimensions presented by the sticks of rod material being transferred.

Disclosure of the Invention

The stated objects are substantially realized in a unit for transferring sticks of rod material used in the manufacture of tobacco products, of which the features are as recited in one or more of the claims appended.
The invention will now be described in detail, by way of example, with the aid of the accompanying drawings, in which:

figure 1 shows a unit for transferring sticks of rod material as used in the manufacture of tobacco products, seen in elevation and embodied according to the present invention;
figure 2 is a perspective view of the transfer unit in figure 1;
figure 3 shows the transfer unit of figure 1 in a view from above, with certain parts omitted better to reveal others;
figure 4 is an elevation view of the transfer unit as in figure 1, shown with certain parts omitted better to reveal others;
figure 5 illustrates the transfer unit of figure 1 in operation;
figure 6 is a perspective view of the transfer unit in figure 1, shown with certain parts omitted better to reveal others.

Referring to the accompanying drawings, numeral 1 denotes a unit according to the present invention, in its entirety, for transferring sticks S of rod material (as defined in the foregoing preamble) used in the manufacture of tobacco products.
The unit 1 comprises two feed channels 2a and 2b extending parallel one with another and spaced apart at a predetermined pitch p, along which to direct respective successions of sticks S emerging from a dual rod maker (not illustrated). The two feed channels 2a and 2b are connected, for example, to the outfeed stage T of a dual rod type machine (as illustrated schematically in figures 3 and 6) by which continuous cigarette or filter rods are first fashioned and then cut into discrete lengths. The predetermined pitch p, between centres of the two feed channels 2a and 2b, is therefore dictated by the distance between the two channels T1 and T2 of the outfeed stage T and cannot be altered.
The unit 1 further comprises a drum 3 rotatable about an axis X parallel to the feed channels 2a and 2b; the drum 3 presents a plurality of flutes 4 ordered consecutively around its peripheral surface of revolution and alignable in pairs with the feed channels 2a and 2b in such a way as to take up the sticks S emerging from the dual rod maker.
The sticks S are thus directed repetitively into the flutes 4 and caused to advance as one with the rotating drum 3, before being released in ordered and consecutive sequence to a further machine on which they will undergo further processing steps.
The further machine in question might consist in a filter tip attachment machine (not illustrated), by way of example, in which case the sticks of rod material could consist either in sticks cut from a tobacco rod or sticks cut from a filter rod.
As depicted clearly in the accompanying drawings, the single flutes 4 of the drum 3 are set apart one from the next at a distance less than the pitch p between the feed channels 2a and 2b.
Moreover, the single flutes 4 of the drum 3 are identical one to another, equispaced, and occupy the full longitudinal dimension of the drum 3. Each flute 4 presents a flared entry portion 5 to the advancing stick S, on the side of the drum facing the feed channels 2a and 2b, so that the sticks S are guided naturally into the relative flutes 4. The drum 3 is also equipped with aspirating means 6 operating along each flute 4 in such a way as to retain the sticks S during the transfer step, that is to say during the rotation of the drum 3. More exactly, such aspirating means 6 comprise a vacuum pump (not illustrated), which might be installed internally of the drum 3 or remote from the drum 3, also a plurality of holes 7 (visible in figure 2) located in the flutes 4 and in fluid communication with the vacuum pump, in such a way as to generate a negative pressure at the surface of the flutes 4 and thus retain any sticks S placed therein.
To advantage, the two flutes 4 of each successive pair presented to the feed channels 2a and 2b will always be separated by two intermediate flutes 4. In other words (see figures 1, 3 and 4), when two flutes 4 are positioned in alignment with the feed channels 2a and 2b, these same two flutes are not directly adjacent, but spaced apart by a distance equivalent to the width of two further flutes.
The rotation of the drum 3, that is, the motion by which sticks S are transferred from one machine to another, occurs at a constant angular velocity and in such a way as to induce a displacement p1, equivalent to 2/3 of the pitch p between the two feed channels 2a and 2b, each time a pair of sticks is taken up by a pair of flutes 4.
For convenience of illustration, as evident in figure 5, the dimensional and directional symbols adopted in the specification are referred to the drum 3, and accordingly, the displacement p1 of the single flute 4 is measured along an arc coinciding with a circumference R passing through the centres of the flutes 4; similarly, the pitch p dividing the two feed channels 2a and 2b is measured along an arc of the same circumference R. The same result could be obtained nonetheless adopting a different system of reference, based for example on the two feed channels 2a and 2b, provided that all of the various distances are measured concordantly with the system selected.
To enable a smooth passage of the sticks S into the flutes 4, the drum 3 rotates tangentially to the two feed channels 2a and 2b so that the pairs of flutes 4 will be positioned at the same height as the channels when in alignment.
The transfer unit 1 also incorporates impeller means 8 operating on the feed channels 2a and 2b in such a way as to gain a further enhancement of the effectiveness with which the sticks S are directed into the flutes 4 of the drum 3.
The impeller means 8 comprise a first pair of rollers 9 and a second pair of rollers 10 located downstream of the feed channels 2a and 2b, by which respective sticks S of rod material are taken up, accelerated and directed into the flutes 4 of the rotating drum 3.
The impeller rollers of each pair 9 and 10 rotate tangentially to the stick S on which they operate, and occupy respective planes Z1 and Z2 (indicated by phantom lines in figure 4) inclined in relation to the plane Z0 (indicated by a phantom line in figure 1) occupied by the two feed channels 2a and 2b. Thus, each pair of impeller rollers 9 and 10 will interact with a predetermined portion of the relative stick S of rod material. More precisely, since each of the sticks S advancing along the two channels 2a and 2b presents a gummed joint line in a predetermined position, extending along its full length, the rollers 9 and 10 are angled in such a way as to avoid any contact with the gummed joint and ensure that the integrity of the stick S is not degraded. In effect, and to reiterate, the sticks S of rod material are received directly from a dual rod type machine, and since the two rods are also gummed simultaneously by the machine, the sticks S will arrive at the unit 1 with the gum still not completely dried.
Moreover, and to advantage, the impeller rollers of the second pair 10 lie parallel to those of the first pair 9, and the two pairs overlap at least in part.
Accordingly, the two pairs of impeller rollers 9 and 10 interact with relative longitudinal portions of sticks S that are identical one to another, that is, engaging in contact at identical distances from the ends of two stick S advancing side by side, so that both of the sticks S advancing along the two feed channels 2a and 2b are subjected to the same axial acceleration, applied at identical points and at the same instant.
To this end, the two impeller rollers 9a-9b and 10a-10b of each contrarotating pair 9 and 10 are driven at a peripheral velocity at least equal to the linear velocity of the sticks S advancing along the two feed channels 2a and 2b. Preferably, the peripheral velocity of the rollers will be greater than the linear velocity of the sticks S, so that the sticks can be accelerated toward the drum 3. The impeller rollers 9a-9b and 10a-10b are set in rotation by one or more drive means, coupled to suitable transmission components.
In the preferred embodiment illustrated, more precisely, the drive means consist in an electric motor 11, whilst the transmission consists in a drive pulley 12 keyed to the motor 11 and linked to respective pulleys 13 and 14 associated with each impeller roller 10a and 10b of the second pair 10. As illustrated in figure 6, the pulleys 12, 13 and 14 are interconnected by a belt 15 in such a way that the two rollers 10a and 10b are made to rotate in opposite directions. To be precise, of the two rollers 10a-10b making up the second pair 10, only the roller denoted 10b is indicated in figure 6 for convenience of illustration.
In like manner, the impeller rollers 9a and 9b of the first pair 9 are power driven, coupled by way of a belt (not illustrated) to the aforementioned motor 11 driving the second pair 10 of rollers.
To advantage, the transfer unit 1 also comprises inspection means 16 that will allow of exposing the impeller rollers 9a-9b and 10a-10b and the two feed channels 2a and 2b to view.
In particular, such inspection means 16 include a bottom plate 17 presenting the feed channels 2a and 2b, which can be mounted or integral, and carrying the two impeller rollers of the first pair 9, also a top plate 18 on which the rollers of the second pair 10 are mounted. The top plate 18 can be moved between an operating position (shown in figures 1, 4 and 5), placed over the bottom plate 17, and an inspection position (shown in figure 2) distanced from the selfsame bottom plate 17.
With this arrangement, should a malfunction of the unit 1 occur, corrective action can be taken directly on the impeller rollers 9a-9b and 10a-10b and/or on the feed channels 2a and 2b.
The aforementioned drive means can be installed directly on the face of the bottom plate 17 and/or of the top plate 18, or internally of the plates. In a preferred solution, as indicated in figure 6, the electric motor 11 is housed internally of the bottom plate 17.
To enable movement between the operating position and the inspection position, the bottom plate 17 and top plate 18 are connected by a hinge 19; with this arrangement, the top plate can swing away from the bottom plate 17, opening in the manner of a book to allow inspection of the impeller means 8 and the feed channels 2a and 2b.
In operation, the transfer unit 1 functions as indicated schematically in figure 5. Two sticks S1 of a first pair are guided into two first flutes 4 presented to the feed channels 2a and 2b, whereupon the drum 3, rotating at constant angular velocity in the direction of the arrow F in figure 5, will bring two further flutes 4 into alignment with the feed channels 2a and 2b as soon as these are ready to release a second pair of sticks S2. The second flutes 4 are distanced from the first flutes which took up the first pair of sticks S1, by a gap 2/3 of the pitch p between the feed channels 2a and 2b. The sticks S2 of the second pair are duly transferred to the rotating drum 3, which then brings two third flutes 4 into alignment with the feed channels 2a and 2b. Likewise in this case, the third flutes 4 are distanced from the second flutes by a gap 2/3 of the pitch p between the feed channels 2a and 2b. The process of filling the drum continues in the manner described, and each flute 4 of the drum 3 is thus able to admit a respective stick S of rod material.
Importantly, by displacing the pairs of flutes 4 through a distance 2/3 of the pitch p between the feed channels, with each pair of sticks S taken up, the rotational speed of the drum can be reduced by 1/3 compared to that of drums in prior art units, or alternatively, maintaining the same speed of rotation, the number of sticks transferred can be increased by 1/3.

Claims

A unit for transferring sticks of rod material used to manufacture tobacco products, comprising two parallel feed channels (2a, 2b) spaced apart at a predetermined pitch (p), along which to direct and convey respective successions of sticks (S) of rod material emerging from a dual rod maker, also a drum (3) set in rotation about an axis (X) disposed parallel to the feed channels (2a, 2b), presenting a plurality of flutes (4) ordered consecutively around a relative peripheral surface of revolution and alignable in pairs with the feed channels (2a, 2b) so as to take up the sticks (S) advancing along the selfsame channels (2a, 2b), characterized in that each flute (4) of the drum (3) is separated from the adjacent flute by a distance less than the pitch (p) between the two feed channels (2a, 2b).
A unit as in claim 1, wherein the flutes (4) are equispaced one from the next.
A unit as in claim 1 or 2, wherein the drum (3) presents two flutes (4) between each pair of flutes alignable with the feed channels (2a, 2b).
A unit as in claim 3, wherein the drum (3) rotates through an angle that induces a displacement (p1) of each flute (4) equivalent to two thirds of the pitch (p) between the two feed channels (2a, 2b), each time a pair of sticks (S) of rod material is taken up by a pair of flutes (4).
A unit as in preceding claims, wherein the drum (3) rotates at a constant angular velocity.
A unit as in preceding claims, comprising impeller means (8) operating along the feed channels (2a, 2b) and serving to direct the sticks (S) of rod material into the flutes (4) of the drum (3).
A unit as in preceding claims, wherein the drum (3) rotates tangentially to the feed channels (2a, 2b), thereby rendering the pairs of flutes (4) alignable at the same height as the feed channels (2a, 2b).
A unit as in preceding claims, wherein the single flutes (4) incorporate respective flared entry portions (5) offered to the feed channels (2a, 2b), along which the sticks (S) of rod material are guided naturally into the corresponding flutes.
A unit as in preceding claims, wherein the drum (3) comprises aspirating means (6) operating along each of the flutes (4), by which the sticks (S) are retained during the rotation of the drum (3).
A unit as in claim 6, wherein impeller means (8) comprise a first pair of rollers (9) and a second pair of rollers (10) located downstream of the feed channels (2a, 2b), by which respective sticks (S) of rod material emerging from the feed channels (2a, 2b) are engaged, accelerated and directed into the flutes (4) of the rotating drum (3).
A unit as in claim 10, wherein the single impeller rollers (9a, 9b, 10a, 10b of each pair (9, 10) rotate tangentially to the stick (S) with which they interact, occupying respective planes (Z1 Z2) inclined in relation to the plane (Z0) occupied by the two feed channels (2a, 2b), and positioned in such a way as to engage predetermined portions of the sticks (S).
A unit as in claim 11, wherein the rollers (10a, 10b of the second pair (10) are disposed parallel to and at least partially overlapping the rollers (9a, 9b) of the first pair (9), so as to engage the same portions of corresponding sticks (S) of rod material as are engaged by the rollers of the first pair (9).
A unit as in claims 10 to 12, wherein the impeller rollers (9a, 9b, 10a, 10b) rotate at a peripheral velocity at least equal to the linear velocity of the sticks (S) of rod material advancing along the feed channels (2a, 2b).
A unit as in claims 10 to 13, comprising means (16) allowing inspection of the impeller rollers (9a, 9b, 10a, 10b) and the feed channels (2a, 2b).
A unit as in claim 14, wherein inspection means (16) are composed of a bottom plate (17) presenting the feed channels (2a, 2b), mounted or embodied integrally, and carrying the first pair of impeller rollers (9), and a top plate (18) carrying the second pair of impeller rollers (10), of which the top plate (18) is capable of movement between an operating position, placed over the bottom plate (17), and an inspection position distanced from the bottom plate (17).
A unit as in claim 15, wherein the bottom plate (17) and/or the top plate (18) comprise respective drive means by which the first pair (9) of impeller rollers and the second pair (10) of impeller rollers, respectively, are set in rotation.
A unit as in claim 15 or 16, wherein the top plate (18) is hinged to the bottom plate (17) and capable thus of movement between the operating position and the inspection position.
A unit as in preceding claims, wherein the sticks (S) of rod material are cigarette sticks.
A unit as in claims 1 to 17, wherein the sticks (S) of rod material are filter plugs.
A system for the manufacture of tobacco products, comprising at least one transfer unit (1) as in one or more of the preceding claims.
A method of transferring sticks of rod material used to manufacture tobacco products, including the step of feeding a first pair of sticks (S1) of rod material into two peripheral flutes of a drum (3) presenting a plurality of such flutes (4) alignable with feed channels (2a, 2b) along which the sticks are advanced, characterized in that it includes the further steps of rotating the drum (3) about an axis of rotation (X) disposed parallel to the two channels (2a, 2b) through an angle equivalent to two thirds of the pitch (p) between the two feed channels (2a, 2b), so as to align two further flutes with a second pair of sticks (S) emerging from the feed channels (2a, 2b), and directing the second pair of sticks into the two further flutes.
A methods as in claim 21, wherein the drum (3) rotates at constant speed.
A method as in claim 21 or 22, including the step of accelerating the sticks (S) of rod material when directed into the flutes.
A method as in claim 23, wherein the acceleration induced in the sticks of rod material is longitudinal only.
A method as in claim 21, wherein the sequence of steps by which sticks of rod material are directed into the flutes of the drum (3) is repeated a predetermined number of times in such a manner that a plurality of flutes occupying at least one circular sector of the drum (3) can be filled with respective sticks of rod material.