DE69714093T2 - Feed hopper for sensitive, cylindrical objects, in particular for cigarettes and in particular in cigarette packaging machines - Google Patents

Description

The invention relates to a feed hopper for delicate cylindrical objects, in particular cigarettes or the like, and particularly for use in cigarette packaging machines with a space for a random quantity of cigarettes arranged parallel to one another, which has at least one outlet opening in its base with at least one outlet channel, in particular several outlet channels, which extend next to one another and in the same essentially vertical direction, each of these channels being intended to receive a vertical row of individual cigarettes with an essentially vertical arrangement, one lying above the other, an air flow being fed within the channel or channels or at least partially within them to the outlet of the cigarettes in the direction of the discharge of the cigarettes and this air flow in the direction of the outlet opening being formed by air blown in under pressure from a point which lies in front of the outlet opening of the channel or channels, according to the preamble of claim 1.

A feed funnel of this type is known from the publication DE-A 20 06 425. According to this state of the art, the air flow in the cigarette channels is only generated by blowing air under pressure into these channels.

These funnels, which are widely used in well-known packaging machines, do not ensure that the cigarettes fall sufficiently safely and quickly and are therefore an obstacle to the possibility of increasing the working speed of packaging machines.

The invention is therefore based on the object of creating a feed funnel of the above-mentioned type in such a way that the above-mentioned retraction can be avoided by simple and inexpensive means, a rapid and safe fall of the cigarettes into the feed station is possible in order to lead to a considerable increase in the working speed of packaging machines without the risk of malfunctions due to incorrect or faulty feeding of cigarettes.

The invention solves the above-mentioned problems by a feed hopper of the type described above, which is characterized by means for combining blown air and suction in the entire channel or channels or in a part or parts thereof and even alternately in some sections of the channel or channels, so that in some sections of the channel or channels the air flow is blown in and in some other sections suction is generated.

According to a preferred embodiment, each outlet opening has a plurality of outlet channels into which the cigarettes fall by gravity in a substantially vertical position, and means are provided for blowing air or other gases into each channel separately from a predetermined point at the upper end of the channels from the suction side of the cigarette to the exit region of the cigarettes.

In particular, when feeding the cigarettes by a movement transverse to their axis, the means for injecting air consist of a plurality of streams distributed along the axial length of the cigarettes and oriented so as to be inclined with respect to the sliding movement of the cigarettes within the channels. Advantages can be taken of the air injected, which are formed by streams branching off from the lateral walls delimiting the outlet channels and arranged parallel to the axis of the cigarettes, these streams being inclined with respect to the sliding movement and converging towards the outlet end of the channels.

A funnel according to the embodiment described above comprises, on the opposite side walls which delimit the channels, rows of injection nozzles arranged opposite one another, the axis of which is inclined with respect to the direction of displacement of the cigarettes towards the opposite wall, each of the rows of nozzles coming from a distribution chamber.

In the case of a plurality of channels connected to each opening for the exit of the cigarettes, a common distribution chamber for the blow-out nozzles is provided, which opens into two adjacent channels, this distribution chamber being provided in the corresponding partition between the two adjacent exit channels.

The advantages of the present invention are obvious in the means described above. The air flow has, in addition to exerting a certain impact movement, on the cigarettes within the individual channels, the additional function of limiting friction between the cigarettes and the side walls of the channels. Therefore, the fall of the cigarettes within the channels is uniform, that is, without delay or inhibition and takes place at the necessary speed, and therefore an increase in the working speed downstream of the machine is possible.

An air flow, usually obtained by blowing, can also be modulated and/or controlled in terms of flow rate, speed and power, with a consequent possible control of the movement exerted on the cigarettes to the maximum extent and according to the current needs.

According to a further improvement of the invention, a station is provided for the formation of at least one coplanar row of cigarettes, called an array of cigarettes, in which the aforementioned are arranged neatly next to each other and the station comprises a support surface for this array provided below the outlet of the funnel.

This support surface for the arrangement of cigarettes is formed at least partially by a suction process.

The suction means may act on all the cigarettes in the arrangement or only on some of them, for example on those which are themselves arranged at the end of the arrangement.

According to a preferred embodiment, the support surface comprises several rows of holes through pipes to suction means, the latter communicating, these rows being aligned and spaced such that at least some of the cigarettes fall out of the outlet of the funnel, each outlet being able to be arranged to its corresponding row of holes.

The holes are relatively small in relation to the size, especially the diameter of the cigarettes. The individual row of suction holes can extend over the entire length of the corresponding cigarette.

The above-mentioned suction means allow both a downward acceleration of the cigarettes in the last downward section of the channels of the funnel (4 mm) on the support surface and to prevent rebound in order to maintain correct reception of the cigarettes' arrangement on the surface. All this can be achieved without mechanical guidance or a slight lateral retention movement by mechanical guides to avoid damage to the cigarettes caused by compression.

Furthermore, the suction means keep the support surface clean against deposits of material, the accumulation of which can, over time, create obstacles to the free sliding movement of the cigarettes on the support surface.

As an alternative to that described above, the support surface can be designed at least partially for suction operation, at least partially for blowing operation and at least partially balanced with atmospheric pressure or at least partially variable in relation to the suction movement.

This advantage can be achieved in various ways. In particular, a connection can be provided, thanks to switching means, between some or all of the holes of the support surface, alternatively to a vacuum source and to an atmospheric pressure or to a pressurized gas or air source. Otherwise, it is also possible to modulate the suction movement so that the holes operate within a range between predetermined maximum and minimum values. The whole can be synchronized with the phase of the cigarettes falling onto the support surface, the waiting phase and the phase of removal from the support surface to the tray conveyor, as well as with any phases corresponding to dead times in which the support surface is idle and busy with the blowing and suction phases in the channels of the hopper. The compressed air can in particular be blown out of the holes during a dead time in which the support surface is idle, in order to blow out the waste material instead of sucking it in. Furthermore, the suction can be increased during the falling of the cigarette onto the support surface and decreased in a discontinuous or continuous manner or even stopped during the phase in which the cigarettes are moved from the support surface to the subsequent conveyor.

In combination with the downward air flow and the suction exerted in the channels of the funnel at its lower end, the suction exerted on the support surface holds the cigarette in a predetermined position against any residual downward flow not compensated by the suction means in the lower part of the channels.

Further improvements of the invention are the subject of the dependent claims.

The characteristics of the invention and the advantages derived therefrom will become more apparent from the following description of an illustrated embodiment, which is not limited to the example of the accompanying drawings. They show:

Fig. 1 is a sectional view in relation to a vertical plane transverse to the axis of the cigarettes from an outlet opening of a funnel according to the invention,

Fig. 2 is a sectional view in relation to a vertical plane parallel to the axis of the cigarettes running from the outlet opening according to Fig. 1,

Fig. 3 shows an enlarged detail of the exit area, which comprises the exit opening according to a different embodiment of the invention,

Fig. 4 is a front view of a shaping feed station for cigarette assemblies, which is provided in combination with the funnel according to the previous figures,

Fig. 5 is a corresponding plan view of the station according to Fig. 4,

Fig. 6 is a sectional view of the station according to the previous Figs. 4 and 5.

A cigarette feed hopper according to Figures 1 to 3, in particular for feeding a unit from a packaging machine with the function of forming a sequence of ordered groups of cigarettes, comprises at least one, generally three cigarette outlet openings 1, which are supplied with a predetermined number of downwardly directed channels 2.

The cigarettes S are provided with their axes aligned horizontally and arranged parallel to each other, with the sloping channels essentially are arranged vertically. In particular, the latter converge at a slight angle towards the lower outlet of the cigarettes. Each downwardly extending channel 2 is slightly wider or, within tolerance limits, substantially identical to the diameter of the cigarettes S, so that in each downwardly extending channel 2 a substantially vertical line of individual cigarettes S is formed which fall by gravity onto a transfer plate 3 associated with the lower end of the outlet opening 1.

The downwardly falling channels 2 of each opening are separated by intermediately arranged knife-shaped openings 4 which taper from the upper inlet end of the channels 2 to the lower outlet end of the channels themselves to form thin foils. By this design, a horizontal arrangement SC of adjacent cigarettes S is formed on the transport plate 3 in order to feed them to means (not shown in detail) for forming ordered groups of cigarettes, which are known for example as tray conveyors or the like.

Immediately above each upper end of the lateral walls 4 of the channels 2, means 6, in particular rollers, are provided, which preferably comprise a rounded or polygonal, in particular square profile, which are driven in a reciprocating and rotating movement about their axes. The rollers 6 are aligned with their axes parallel to one another and arranged alternately in two different planes to one another. These are driven by a rack 7 in a reciprocating movement in the direction of their longitudinal axes. The rack 7 is slidably received behind the rear wall of the hopper and engages toothed extensions 106 arranged axially behind the shafts 6.

In the side walls 4, 101 delimiting the channels 2, nozzles for supplying air streams under pressure are provided essentially in their upper ends. These nozzles, designated with number 8, are for example transverse holes in the side walls 4 delimiting the channels 2, which open into the inner section of the corresponding channel and branch off from a chamber 9 for supplying compressed air. The nozzles designed as holes 8 are arranged with their axes in accordance with the direction according to which they overlap the air stream and converge slightly rising in a V-shape with respect to the nozzles of opposite side walls 4, 101 or the same channel and towards the outlet end of the same channel.

Preferably, a row of holes or nozzles 8 is provided, preferably on each side wall of each channel, extending along the entire axial length of the cigarettes or at least partially thereof. The nozzles or holes 8 of each line may be equally spaced from each other or may be arranged more or less concentrated in different areas.

The distribution chambers 9 in the walls 4 separating two adjacent channels preferably comprise recesses which extend in the axial direction of the cigarettes through the thickness of the walls 4 separating the channels 2. This arrangement allows one distribution chamber to simultaneously supply air to the nozzles or bores 8 of one of the two adjacent channels 2.

On the back side, transverse to the axis of the cigarettes of the funnel 1 or the outlet opening 1, in a position which axially coincides with the corresponding end of the distribution chambers 9, an additional feed chamber 10 with a compressed air channel coming from its free back side is provided.

In the compressed air feed circuit, means are provided for adjusting the pressure and/or flow rate, as well as means for switching off the feed operation in such a way as to alternate blowing states and rest states. The blowing, which is produced by rows of nozzles, in this case by each lateral pair of holes 8, creates a downwardly falling air flow inside each channel 2. This air flow, which exerts a force in the same downwardly falling direction of the cigarettes in the channels, also allows a reduction in the friction between the cigarettes S and the walls and prevents the effect of slightly rising arrangements of the cigarettes, which leads either to their catching up in the channel or at least to a slower fall. By this arrangement, the air penetrates between the cigarette S and the lateral wall of the channel 2, keeping the cigarette itself in position.

According to the invention shown in Fig. 3, the air flow directed downwards in the channels 2 is partially formed by a vacuum, i.e. by suction. For this purpose, suction nozzles 12 are provided in an area which is essentially provided at the lower end of the channels 2, i.e. the exit area of the channels themselves. provided in order to generate the downward air flow, through which the cigarettes S are also drawn downwards.

The two means according to Figs. 1 and 2 and Fig. 3 are intended to be combined and to operate either simultaneously in the same area of the channels 2 or alternately in different areas, etc.

Any combination and configuration of suction and/or blowing nozzles is of course possible in order to ensure the best and fastest fall of the cigarettes. The suction nozzles can be adapted exactly as described above in relation to the blowing nozzles 9.

In the figure, each wall of each downwardly falling channel 2 comprises a pair of blowing nozzles and/or suction nozzles 8 and the pairs of nozzles and the corresponding distribution chambers for the outer side walls 101 of the end channels of the opening 1 are provided in the outer side walls of the outlet opening 1.

The possibility of adjusting the pressure or flow rate of the exhaust and/or suction flows allows control of the main characteristics of the downward air flow and therefore of the movement exerted by the latter on the cigarettes. Therefore, the operating conditions of the devices can be easily adapted to the current conditions of the plant, i.e. of the packaging machines.

According to a further improvement of the invention with respect to Figs. 4 to 6, the funnel 15 and its lower three outlets 102 are suitably spaced apart from one another and associated with a common vertical plane.

Below the outlet openings 102 and corresponding thereto, many support surfaces 20 are provided at different heights, with a proper arrangement SC of cigarettes S resting next to one another on each of the support surfaces.

In a laterally staggered position, in which the cigarettes are arranged in an axial direction with respect to the support surface 20, a straight conveyor belt 17 is provided, the two ends of which are open and the axes of which are aligned parallel to the cigarettes lying on the support surfaces 20, the conveyor belt 17 being equipped with means for step-by-step forward movement and with a plurality of box-shaped housings 18.

Near and coaxially opposite the support surfaces and the conveyor belt 17, there are provided a plurality of ejector plates 19 which are moved with a reciprocating motion. Each of the ejector plates 19 moves its corresponding array SC of cigarettes from the adjacent support surface 20 to the corresponding housing 18 of the conveyor belt 17.

The height of the housings 18 and the vertical stacking of the support surfaces 20 enable, during the three successive steps of the transport conveyor, the introduction of three superimposed arrangements SC of cigarettes into the individual housing 18 in such a way that ordered groups of cigarettes are formed, which are fed to a packaging means (not shown) for wrapping them in a package.

Each of the support surfaces 22 has suction means for the cigarettes provided thereon. These suction means can be of any type and in particular comprise a plurality of parallel rows 21 of suction holes 121. These holes are relatively small in relation to the diameter of the cigarettes S, the rows being provided on the surface, and each row corresponds to a row of cigarettes lined up along the surface.

The suction holes 121 of each row 21 on each support surface 20 are connected to a pipe 22, whereby all pipes 22 are connected to a main pipe 23, which is connected to a connecting channel to suction means 24. Each row 21 of the suction holes 121 can extend over the entire length of the corresponding cigarette or at least part of it.

The rows 21 of suction holes 121 in the support surfaces 20 have a number of functional advantages, among which are:

- Control and acceleration of the falling movement of the cigarettes S from the outlet openings 102 and the funnel 15 onto the corresponding support surfaces 20;

- correct sequencing and exact alignment of the cigarettes S on the support surfaces 20, even if a residual flow of air falling downwards in the channels of the funnel reaches them and exerts an arc-shaped movement away from them;

- very well controlled guidance of the arrangements SC of the cigarettes during their transport from the support surfaces 20 to their housings 18 of the conveyor belt 17,

- Cleaning the contact surfaces 20.

These advantages are achieved by very reliable pneumatic means. In this design there is no need for the use of mechanical devices such as oscillating proximity devices, guides or the like, which are not suitable for the very high working speeds of cigarette packaging machines.

The device according to the invention is obviously not limited to the embodiment described here, but it can be modified in many ways, especially in terms of construction. For example, the rows 21 of suction holes 121 can be combined with only some cigarettes of an array SC on the single support surface, in particular those located at the ends of the same array, so that the suction means can be simplified considerably without substantially losing the above-mentioned advantages.

The main lines can furthermore be connected alternately to suction means at atmospheric pressure or to means for producing air or gas under pressure. In this arrangement, the suction effect can be reduced thanks to the simple multi-way switching valves, for example during the movement of the cigarettes from the support surface 20 onto the conveyor or a cleaning blow-out through the holes during the dead times when the surface is unused. In a further alternative, means can be provided for controlling suction flow or power, which can be controlled in such a way as to modulate the suction operation within a range between predetermined maximum and minimum values in a discontinuous or continuous manner by synchronizing the phases of falling and displacement of cigarettes, the phases of blowing and suction of the falling air flow in the channels and with possible dead times. In this way, for example, an increase in suction in the phase of falling and a steady decrease in the phase of displacement of the cigarettes can be provided. The above is without to abandon the leadership principle, as set out above and claimed below.

The invention is of course not limited to the embodiments described and illustrated herein, but can be modified, for example, in terms of constructions, without departing from the guiding principle described above and claimed below.

Claims (21)

1. Feed funnel for sensitive cylindrical objects, in particular cigarettes or the like and especially for use in cigarette packaging machines, with a space for a random number of cigarettes aligned parallel to one another, which has at least one outlet opening (1) at its bottom, with at least one outlet channel (2), in particular several outlet channels (2) which extend next to one another and in the same, essentially vertical direction, each of these channels being provided for receiving a vertical row of individual cigarettes with an essentially vertical arrangement in which one lies above the other, an air flow being fed (8, 9) in the direction of the exit of the cigarettes (S) within the channel or channels (2) or at least partially within them to the exit of the cigarettes (S) and this flow in the direction of the exit opening is formed by air blown in under pressure from a point which lies in front of the exit opening of the channel or channels (2), characterized in that means are provided for combining blown air and suction in the whole of the ducts or parts thereof and even alternately in some sections of the duct(s) (2), so that in some sections of the duct(s) the air flow is blown in and in some other sections suction is created. 2. Funnel according to claim 1, characterized in that each outlet opening (1) has a plurality of outlet channels (2) into which the cigarettes fall by gravity in a substantially vertical position and means are provided for blowing air or other gases into each channel (2) separately from a predetermined point at the upper end of the channels (2) from the suction side of the cigarettes (S) to the outlet area of the cigarettes (S). 3. Funnel according to claim 1 or 2, characterized in that the cigarettes (S) are fed by movements transverse to their axis and the means for blowing air comprises a plurality of streams distributed along the axial length of the cigarettes and oriented in such a way that that they are inclined with respect to the sliding movement of the cigarettes within the channels. 4. Funnel according to claim 3, characterized in that the blown-in air is generated by streams coming from the side walls delimiting the outlet channels (2) and running parallel to the axis of the cigarettes (S), these streams being oriented in such a way that they are inclined with respect to the sliding movement and approach a V-shaped configuration in the direction of the outlet end of the channels (2). 5. Funnel according to one or more of the preceding claims, characterized in that on the opposite side walls which delimit the channels, there are provided rows of injection nozzles (8) arranged opposite one another, the axis of which is inclined in relation to the pushing direction of the cigarettes (S) in the direction of the opposite wall (4, 101), each of the rows of nozzles (8) coming from a distribution chamber (9). 6. Funnel according to claim 5, characterized in that, in the case of a plurality of falling channels (2) connected to each opening (1) for the exit of the cigarettes (S), a common distribution chamber (9) is provided for the blow-out nozzles (8), which opens into two adjacent channels (2) and this distribution chamber (9) is provided in the corresponding partition wall (4) between the two adjacent falling exit channels (2). 7. Funnel according to one or more of the preceding claims, characterized in that the distribution chambers (9) are formed by recesses extending parallel to the axis of the cigarettes (S) in the corresponding walls (4, 101) which delimit the falling outlet channels (2) and come out of the rear and enter a common feed chamber (10) which can be connected to a pressure source. 8. Funnel according to one or more of the preceding claims, characterized in that the compressed air supply circuit can have means which prevent a compressed air filling process of the nozzles and/or are provided for adjusting the pressure and/or the flow rate. 9. Funnel according to one or more of the preceding claims, characterized in that one or more suction nozzles (12) are provided in the lower end of the walls delimiting the falling channels (1), which are arranged in the same way and connected to a suction source as the blow-out nozzles (8) according to one or more of the preceding claims. 10. Funnel according to one or more of the preceding claims, characterized in that it is provided in connection with a station for the formation of at least one coplanar row (SC) of cigarettes (S), called an array of cigarettes, in which the aforementioned are arranged neatly next to one another, and the station comprises a support surface (20) for this array (SC) provided below the outlet of the funnel, the support surface for the array (SC) of cigarettes (S) being formed at least partially by a suction process (21, 121, 22, 23, 24). 11. Funnel according to claim 10, characterized in that the suction-operating support surface (20, 21, 121, 22, 23, 24) comprises suction means for controlling and accelerating the falling movement of the cigarettes (S) from the outlet (102) of the channels (2) onto the support surface (20), for forming and regulating the arrangement (SC) of the cigarettes (S) on the surface (20), for guiding this arrangement (SC) in a measured manner while the latter is being moved from the support surface (20) into its associated packaging (18) by a conveyor device (17) and for eliminating the at least partially blowing air flow in the channels (2) which keeps the cigarettes (S) in their correct position. 12. Funnel according to claim 10 or 11, characterized in that the suction means (21, 121, 22, 23, 24) comprises a plurality of parallel rows (21) of suction bores (121) provided on the support surface (20), these rows (21) of bores (121) being aligned and spaced in length to coincide with the support area in the support surface (20) of at least some of the cigarettes (S) in their intended position within the arrangement. 13. Funnel according to claim 12, characterized in that pipes (22, 23) are provided which connect at least some of the rows (21) of the bores (121) or some of the bores (121) of the different rows (7) to a common vacuum source (24). 14. Funnel according to one or more of the preceding claims 10 to 13, characterized in that a row (121) of holes (21) can be provided only for some cigarettes (S) of the arrangement (SC) of cigarettes or for each cigarette (S) of the arrangement of cigarettes (SC) and these arrangements (21) are arranged in such a way as to coincide with the contact area of the corresponding cigarette on the support surface (20). 15. Funnel according to claim 14, characterized in that a row (21) of holes (121) is provided only for each of the two cigarettes (S) at the end of the arrangement (SC) of the cigarettes on the support surface (20). 16. Funnel according to one or more of the preceding claims 10 to 15, characterized in that at least some of the rows (21) of bores (121) on the support surface (20) or each of them extends at least partially or substantially over the entire length of the corresponding cigarette (S). 17. Funnel according to one or more of the preceding claims 10 to 16, characterized in that the suction bores (121) of each row (21) open into corresponding pipes (22), it being provided that all of these pipes (22) are connected to a main line, which in turn is connected to a suction opening (24). 18. Funnel according to one or more of the preceding claims 10 to 17, characterized in that the support surface (20) can be alternately manufactured for alternating action by at least partial suction, at least partial blowing and at least partial uniform atmospheric pressure or by at least partially variable suction and/or blowing process. 19. Funnel according to claim 18, characterized in that switching means are provided which alternately open at least some of the bores (121) of the Connect rows (21) or old holes (121) of rows (21) to a vacuum source, to atmospheric pressure or to a pressurized gas or air source. 20. Funnel according to claim 19, characterized in that the vacuum source can be variable in terms of flow rate and suction power and that means are provided for continuous or step-by-step adjustment and modulation of the suction process taking into account one or more predetermined values. 21. Funnel according to one or more of claims 17 to 20, characterized in that the connection of at least some of the holes (121) of the rows (21) to the vacuum source, to the air pressure or to the compressed air source or the suction power supplied by the vacuum source (24) is synchronized with the phase of the cigarettes (S) falling onto the support surface (20), with the transport phase and with the remaining phase in which the support surface (20) is inactive and with the blowing and suction of the air flow in the channels (2), the suction process being reduced or stopped during the conveyance of the cigarettes preferably immediately or in a continuous manner and the compressed air being blown out through the holes (121) in the remaining phase in which the support surface (20) is inactive.