Abstract:
Cigarettes entering a packer are directed en masse into a device comprising a hopper with a number of distinct feed sections, each having a dedicated inlet and outlet and enclosed on one side by an access door, from which the single cigarettes are transferred to respective assembly stations and thereupon formed into ordered groups. Located alongside each inlet is a suction field provided by an array of holes allowing a fluid connection between the hopper and a vacuum duct; a chamber forming part of the vacuum duct houses a valve element able to alternate between an extended active position in which the holes are shut off, and a retracted inactive position in which the holes are able to attract and immobilize the cigarettes, thereby allowing inspection of the feed section by an operator; movement of the valve element is interlocked to the access door.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to a device for feeding ordered groups of cigarettes in a packaging machine.  
         [0002]     The device according to the present invention is described in the following specification, albeit with no limitation in scope implied, as applicable to a cigarette packer in which its function is to feed cigarettes and form them into a succession of ordered groups, each providing the contents of one packet of cigarettes.  
         [0003]     The feed device disclosed comprises a hopper, embodied typically as a flow chamber designed to accommodate cigarettes en masse and associated with a plurality of feed sections.  
         [0004]     Each feed section is furnished with an inlet and a plurality of feed channels, delimited by pairs of baffles, along which the cigarettes advance toward an outlet positioned alongside an assembly station where the single cigarettes are formed into ordered groups.  
         [0005]     The assembly station generally comprises a pusher mechanism by which the ordered groups of cigarettes are transferred into respective conveying elements; the groups are then carried on these same elements toward further processing stations.  
         [0006]     It has been found in certain cases, during the operation of the packer, that cigarettes advancing along the feed channels can become positioned incorrectly and thus impede the smooth progress of the other cigarettes.  
         [0007]     As a direct consequence of this drawback, groups formed from cigarettes transferred to the assembly station may emerge incomplete, and will have to be rejected during the course of subsequent burdensome checking operations.  
         [0008]     Self-evidently, therefore, any impediment to the smooth progress of the cigarettes must be removed as swiftly as possible.  
         [0009]     Ideally, moreover, at the moment when action is taken by the operator to remove the aforementioned impediment, it should be possible to immobilize the advancing cigarettes internally of the affected feed section.  
         [0010]     Cigarette packers of prior art design are not devoid of drawbacks in this regard.  
         [0011]     With machines of conventional design, in effect, cigarettes advancing internally of the single feed sections cannot be brought to a halt effectively and promptly.  
         [0012]     The object of the present invention is to provide a device for feeding ordered groups of cigarettes that will be unaffected by the drawbacks mentioned above in connection with the prior art.  
       SUMMARY OF THE INVENTION  
       [0013]     The stated object is realized according to the invention in a device for feeding ordered groups of cigarettes in a packaging machine, comprising: a hopper incorporating a plurality of feed sections from which cigarettes are directed into respective assembly stations to be formed into ordered groups, each feed section comprising an inlet and an outlet through which the cigarettes are directed, and a plurality of feed channels located between the inlet and the outlet and delimited by pairs of dividing baffles; pusher mechanisms associated one with each assembly station and serving to transfer each of the ordered groups to respective conveying means by which the groups are then directed toward further processing stations, each pusher mechanism singly deselectable in the event of defects being detected in the formation of the groups of cigarettes; means affording access to the feed sections for inspection and maintenance purposes; and means, interlocked to the pusher mechanism or to the access means, by which to block the movement of the cigarettes along the channels toward the assembly station. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     The invention will now be described in detail, by way of example, with the aid of the accompanying drawings, in which:  
         [0015]      FIG. 1  shows a portion of a cigarette packing machine, viewed schematically in a side elevation with certain parts cut away for clarity, and equipped with a device according to the invention illustrated in a preferred embodiment;  
         [0016]      FIG. 2  is a schematic plan view illustrating a portion of the machine in  FIG. 1 , shown with certain parts omitted for clarity and others in section;  
         [0017]      FIG. 3  shows a detail of the feed device in  FIG. 1 , viewed schematically in a front elevation with certain parts cut away for clarity;  
         [0018]      FIG. 4  shows the device of  FIG. 1 , viewed schematically in a side elevation with certain parts in section and others cut away for clarity;  
         [0019]      FIG. 5  shows a second embodiment of the feed device according to the present invention, viewed schematically in a front elevation with certain parts cut away for clarity. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0020]     With reference to  FIG. 1 , numeral  1  indicates a feed device, in its entirety, integrated into a cigarette maker-packer line. The device  1  serves to form single cigarettes  3  into ordered groups  2 , each ultimately providing the contents of a single packet (not illustrated).  
         [0021]     The device  1  comprises a hopper  4 , which in turn incorporates a flow chamber  5  of substantially familiar type, delimited at the front and rear by two flat walls parallel to the viewing plane of  FIG. 1 , of which one only, a rear wall denoted  6 , is indicated in  FIG. 4 ; the hopper  4  is designed to accommodate cigarettes  3  en masse, positioned substantially horizontal and perpendicular to the front and rear walls of the flow chamber  5 .  
         [0022]     Still referring to  FIG. 1 , the hopper  4  further comprises a plurality of feed sections  7 , each of which presenting an inlet  8  and an outlet  9 .  
         [0023]     As illustrated in  FIG. 3 , each feed section  7  comprises a plurality of feed channels  10  arranged side by side and converging toward the outlet  9 , which are delimited laterally by pairs of dividing baffles  11 , likewise mutually convergent.  
         [0024]     Each channel  10  is designed to allow the descent of a relative column of cigarettes  3  along a feed direction denoted F.  
         [0025]     The feed section  7  as a whole is also delimited laterally by respective side walls  12  of which the relative inside faces  12   a  are inclined convergently toward the outlet  9 .  
         [0026]     To ease the passage of the cigarettes  3  through the flow chamber  5  and toward the channels  10 , as illustrated in  FIGS. 3 and 4 , the feed device  1  comprises an agitator device located internally of the chamber  5  and denoted  13  in its entirety. The device  13  in question incorporates a plurality of agitator elements  14 , substantially polygonal in section, activated by drive means  15  in familiar fashion (not illustrated) and in such a way as to rock on relative axes A 1  extending substantially horizontal and perpendicular to the aforementioned walls of the hopper.  
         [0027]     As illustrated in  FIG. 2 , and in accordance with the prior art, the device  1  further comprises a plurality of assembly stations  16 , each located near the outlet  9  of a respective feed section  7 , in which the aforementioned groups  2  of cigarettes are formed.  
         [0028]     Each assembly station  16  comprises a pusher mechanism  17  positioned on one side of the outlet  9  and a guide  18  placed on the side opposite.  
         [0029]     The function of the pusher mechanism  17  is to transfer the ordered groups  2  of cigarettes  3  into respective pockets  19  of a conveyor  20  (familiar in embodiment and not described further) advancing along a feed direction denoted D 1 .  
         [0030]     The pocket conveyor  20  constitutes feed means  21  by which the groups  2  of cigarettes  3  are directed toward further processing stations not illustrated in the drawings.  
         [0031]     Referring to  FIGS. 1 and 3 , each feed section  7  comprises a removable front wall  22  that provides the device  1  with means  23  affording access to the selfsame section  7 , such as will enable an operator to make an inspection and allow the removal of any obstacle to the smooth passage of the cigarettes  3  along the channels  10 .  
         [0032]     In particular, the removable wall  22  consists in a door  24  capable of movement between a first or closed configuration indicated in  FIGS. 1 and 3 , and a second or open configuration, not indicated, in which the inside of the feed section  7  is made accessible.  
         [0033]     The door  24  presents a bottom edge  24   a  coinciding with the top of the outlet  9 , a first side edge  24   b  connected by way of a hinge  25  to one of the side walls  12  of the feed section  7 , and a second side edge  24   c  opposite to the first side edge  24   b.    
         [0034]     The hinge  25  is substantially conventional in embodiment and illustrated in outline only.  
         [0035]     With reference to  FIGS. 1 and 4 , numeral  26  denotes a handle  26  fastened to an outer face  24   d  of the door  24 . Using the handle  26 , the door  24  can be swung on an axis A 2  of the hinge  25  between a closed position, illustrated in  FIG. 3 , and an open position (not illustrated in the drawings) in which the relative feed channel  10  is accessible from the outside for maintenance purposes.  
         [0036]     Mounted to one of the side walls  12  of the feed section  7  is a sensor, denoted  27 , connected to a computerized control unit illustrated schematically in  FIG. 3  as a block  28 .  
         [0037]     The operation of the sensor  27  and of the control unit  28  will be described more fully in due course.  
         [0038]     As illustrated in  FIGS. 3 and 4 , the hinge  25  of the door  24  is mounted to a glide element  29  coupled slidably with three small guide rollers  30  carried by one of the side walls  12  and rotatable freely on respective pivots  31 .  
         [0039]     Accordingly, the opening movement of the door  24  is generated by a combination of movements, with the door  24  itself swinging on the axis A 2  of the hinge  25 , and the hinge  25  sliding together with the glide element  29  in the direction of the arrow denoted F 2 .  
         [0040]     In effect, the compound movement described above is intended to ensure that when the door  24  assumes the open position, it will not encroach on a given area in front of the outlet  9  presented by the feed section  7  of the hopper  4 , which must remain free in order to allow the passage of the aforementioned pockets  19  of the conveyor  20 .  
         [0041]     Still observing  FIGS. 3 and 4 , the rear wall  6  of the hopper  6  presents a plurality of through holes  32  located near to the inlet  8  of each feed section  7 , arranged in a rank and file formation that occupies substantially the full width of the section  7  between the two side walls  12 .  
         [0042]     The holes  32  serve to create a fluid connection between the hopper  4  and a vacuum duct denoted  33 , which is connected in turn to a conventional source of negative pressure illustrated schematically in  FIG. 4  as a block  34 .  
         [0043]     More exactly, the holes  32  combine to create a suction field  35  by means of which a plurality of cigarettes  3  can be held in contact with the flat rear wall  6  of the hopper  4 .  
         [0044]     The suction field  35 , its constituent holes  32  and the vacuum duct  33  together establish means  36  of pneumatic type by which to block the movement of the cigarettes  3  along the feed channels  10 .  
         [0045]     With reference to  FIG. 4 , the vacuum duct  33  comprises a chamber  37  in communication with the holes  32  and accommodating a valve element  38  such as will cut off the fluid connection between the hopper  4  and the vacuum duct  33 .  
         [0046]     To this end, the valve element  38  is capable of movement, in a direction denoted D 2 , between a first active position, extended and disallowing aspiration through the holes  32 , and a second inactive position, retracted as shown in  FIG. 4  and allowing aspiration; the movement of the valve element  38  between the first and second positions is induced, through the agency of relative actuator means (not indicated), in response to a signal indicating the status of the pusher mechanism  17  and/or the door  24  aforementioned.  
         [0047]     The valve element  38  furnishes the device  1  with means  39  by which to shut off the suction field  35 . In normal operation, as evident from  FIG. 1 , cigarettes  3  occupying the flow chamber  5  of the hopper  4  will gravitate toward each of the feed sections  7  presented by the selfsame hopper  4 .  
         [0048]     With reference to  FIGS. 3 and 4 , the movement of the cigarettes  3  is assisted by the agitator elements  14 , which are able to prevent the flow from clogging upstream of the inlet  8  at each of the feed sections  7 ; in effect, any such congestion could create a void in the flow of cigarettes  3  and break its continuity.  
         [0049]     Thus, the subsequent passage of the cigarettes  3  into and along the single channels  10  will also be assisted by a relative agitator element  14  located internally of the flow chamber  5 , near the top end of the channel  10 .  
         [0050]     The agitator elements  14  are coupled in familiar fashion to the aforementioned drive means  15  and caused to rock on their axes A 1 , alternating at a predetermined frequency and amplitude.  
         [0051]     It can happen on occasion, having passed into the feed channels  10 , that certain of the cigarettes  3  become positioned incorrectly within the selfsame channels  10 ; in this situation, the flow of single cigarettes  3  along a given channel  10  may be halted completely.  
         [0052]     In order to exclude any possibility that groups  2  of cigarettes  3  could emerge incomplete from the assembly station  16 , the machine can be equipped with conventional means (not illustrated) such as will detect a substandard group  2  of cigarettes  3  and respond, for example, by stopping the pusher mechanism  17 .  
         [0053]     In this situation, that is to say with the pusher mechanism  17  idle and no groups  2  of cigarettes  3  being transferred to the pocket conveyor  20 , the aforementioned control unit  28  will pilot the valve element  38 , by way of the aforementioned actuator means (not illustrated), to shift from the active first position (not illustrated), extended and disallowing aspiration, to the inactive second position shown in  FIG. 4 , retracted and allowing aspiration.  
         [0054]     Still referring to  FIG. 4 , the retraction of the valve element  38  causes the holes  32  to connect with the chamber  37 , and the hopper  4  is able to communicate with the vacuum duct  33  connected to the negative pressure source  34 . In this situation, the cigarettes  3  positioned nearest to the suction field  35  are attracted to the holes  32  and become attached stably, by way of their respective butt ends, to the rear wall  6  of the hopper  4  in which the holes  32  are located.  
         [0055]     As a result of the aspirating force generated through the suction field  35 , accordingly, a given number of cigarettes, denoted  40  in  FIG. 4 , will remain substantially locked against the rear wall  6  of the hopper  4  and impede any downward shift of the mass of cigarettes, denoted  41 , occupying the part of the flow chamber  5  immediately above the feed section  7  affected by the blockage.  
         [0056]     In like manner to the situation described above, the control unit  28  will pilot the opening movement of the valve element  38  on receiving a signal from the sensor  27  to indicate that the door  24  is open. In practice, on becoming aware of a malfunction in any of the feed sections  7 , the operator opens the door  24  and the sensor  27  will immediately relay a signal to the computerized control unit  28 , which in turn activates the valve element  38  so that the cigarettes  3  can be immobilized at the inlet of the feed section  7 .  
         [0057]      FIG. 2  shows the operational connection between the control unit  28  and the pusher mechanism  17 , also the connections linking the control unit  28  to the valve element  38  and the sensor  27 , represented in this instance as blocks.  
         [0058]      FIG. 3  shows the operational connection between the control unit  28  and the sensor  27  indicating the open/closed status of the door  24 , also the connections linking the control unit  28  to the pusher mechanism  17  and the valve element  38 , again represented by blocks.  
         [0059]      FIG. 4  shows the operational connection between the control unit  28  and the valve element  38 , also the connections linking the control unit  28  to the pusher mechanism  17  and the sensor  27 , represented by blocks.  
         [0060]     In short, the movement of the valve element  38  between the first and second positions is piloted, through the agency of the aforementioned actuator means, by a change in the operating status of the pusher mechanism  17  and/or of the door  24 .  
         [0061]      FIG. 5  illustrates an alternative embodiment of the present invention in which means  36  by which to block the movement of the cigarettes are mechanical in embodiment.  
         [0062]     More particularly, such means comprise agitator elements  14  rendered capable of movement between a normal operating configuration, in which motion is transmitted to the cigarettes  3  occupying the flow chamber  5  so as to ease their passage toward the feed channels  10 , and a configuration in which the feed channels  10  are occluded and the cigarettes  3  unable to advance.  
         [0063]     In other words, the agitator elements  14  can be displaced, by means of actuator devices neither illustrated nor described further in the present specification, in such a manner as to create the aforementioned occluding configuration in which cigarettes  3  occupying the flow chamber  5  of the hopper  4  will be prevented from entering a given feed channel  10 , at least in some measure, by the respective agitator element  14 .  
         [0064]     In the example of  FIG. 5 , the movable agitator elements  14  are illustrated in solid lines when positioned to create the occluding configuration, and in phantom lines when positioned for operation in the normal agitating configuration.  
         [0065]     Thus, in the device according to the invention, means  36  by which to block the movement of the cigarettes  3 , whether pneumatic or mechanical, are interlocked to the pusher mechanism and/or to the means  23  affording access to the feed section  7 , which in the embodiments described and illustrated are provided by the door  24 .  
         [0066]     To advantage, moreover, the blocking means  36 , whether pneumatic or mechanical, can be operated selectively and independently for each of the feed sections  7  of the hopper  4 . Halting the advance of the cigarettes  3  within a given section  7  does not therefore impact negatively on the operation of the feed device  1  as a whole, since each section  7  is completely independent of the other sections  7 , and these in effect can continue to feed cigarettes  3  to the respective stations  16  where they are formed into ordered groups  1 . Consequently, there is no break in the continuity with which ordered groups  2  of cigarettes  3  are fed to subsequent processing stations (not illustrated) of the cigarette packer.