Apparatus for feeding cigarettes to a packaging station
BACKGROUND OF THE INVENTION 
     I. Field of the Invention 
     The present invention relates to the information of cigarette packages and particularly to the transfer of completed cigarettes to packaging apparatus with inspection and rejection of defective cigarettes during the transfer procedure. More specifically, this invention is directed to apparatus for delivering completed cigarettes to a packaging station, the apparatus detecting and ejecting defective cigarettes. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character. 
     II. Description of the Prior Art 
     Apparatii for feeding unpackaged cigarettes to a packaging station of a cigarette packaging machine are known in the art. An exemplary prior art cigarette feed apparatus is disclosed in published European application No. 0,100,537. This exemplary prior art cigarette feed apparatus has a delivery shaft which is subdivided into individual guide channels by partitions. A sensor for checking cigarette qualify is associated with each guide channel. A transfer roller, provided with a pair of oppositely disposed cigarette receiving troughs or grooves in its periphery, is positioned in registration with the exit end of each guide channel. The cigarettes move along the guide channels under the influence of gravity and are subsequently individually transferred by the rollers to further guide or delivery channels. An ejector, which may be in the form of an air blast, is positioned to remove defective cigarettes from each roller during the rotation thereof, i.e. the defective cigarettes will be blown out of the receiving troughs in the rollers and thus will not reach the further guide channels through which the cigarettes are delivered to the packaging station. 
     Continuing to discuss exemplary prior art apparatus such as disclosed in the above-referenced European application, the layers of cigarettes which will define a cigarette block to wrapped are formed at the end of the further guide channels. There must, accordingly, always be sufficient cigarettes in the lower portions of the further guide channels to form a complete layer. Since defective cigarettes occur variably in the guide channels, it is necessary to exercise control over the transfer rollers individually to ensure that all of the further guide channels will be populated with a sufficient number of acceptable cigarettes. This requires relatively sophisticated control hardware and results in comparatively complex and expensive apparatus. This control hardware includes filling-level indicators for sensing the presence of an adequate supply of cigarettes in the further guide channels and for controlling the rotational speed of the transfer rollers associated with each guide channel. Even with such comparatively complex apparatus, operational problems have been known to occur when several defective cigarettes occur in succession in a given guide channel. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the above-briefly discussed and other deficiencies and disadvantages of the prior art by providing a novel technique for the simultaneous inspection of and transfer of cigarettes to a packaging station. The present invention also encompasses apparatus for use in the practice of this novel technique which is characterized by uncomplicated and thus reliable construction, the apparatus guaranteeing the delivery of sufficient quantities of acceptable cigarettes to the packaging station. 
     Apparatus in accordance with the preferred embodiment of the present invention includes a feed shaft which is divided into individual elongated guide channels. A quality sensor is associated with each channel. The guide channels terminate adjacent and in vertical alignment with the periphery of a common transfer drum or wheel which is rotatable in steps. The transfer wheel is provided on its periphery with groups of receiving grooves which are spaced so as to be alignable with the exit ends of the guide channels. A retention or blocking device is provided for closing the exit ends of the guide channels during rotation of the transfer wheel. The apparatus also includes means for ejecting defective cigarettes at a location displaced from the exit ends of the group of guide channels. This permits defective cigarettes to be ejected during a period of time when the transfer wheel is stationary. A receiving funnel, which provides communication to a further or downstream array of guide channels, is positioned to receive cigarettes of acceptable quality from the transfer wheel. 
     In accordance with a second embodiment of the invention, the transfer wheel is horizontally offset from the discharge ends of the guide channels and a slide mechanism is employed to push the cigarettes in all of the guide channels horizontally into the transfer wheel when the wheel stops between steps. The second embodiment is otherwise substantially the same as the above-described preferred embodiment. 
     When practising the method of the present invention, employing either of the above-breifly described embodiments, groups of cigarettes are transferred from the lower ends of the guide channels into receiving grooves of a transfer wheel which is rotated intermittently. Defective cigarettes are preferabbly ejected when the transfer wheel is in a standstill position. Cigarettes which are not ejected are delivered into a funnel from which they are extracted to form the layers which define cigarette blocks which are to be wrapped. Cigarettes located at the bottom ends of the guide channels are isolated from the transfer wheel during the rotation thereof. The means which achieves this isolation includes a moveable member which is activated to transfer, or permit transfer under the influence of gravity, the lowermost cigarettes in the guide channels onto the transfer wheel substantially simultaneously. 
     A particularly significant advantage of the present invention is that it may be installed directly on conventional cigarette funnels by which cigarettes are delivered to a packaging station of a wrapping machine. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The present invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawing wherein like reference numerals refer to like elements in the several figures and in which: 
     FIG. 1 is a schematic front elevational view, partly in section, of apparatus for feeding cigarettes to a packaging station of a cigarette packaging machine in accordance with the present invention. 
     FIG. 2 is a cross-sectional side elevation view of the apparatus represented by FIG. 1. 
     FIG. 3 is a view similar to FIG. 1 which depicts apparatus in accordance with a second embodiment of the present invention; and 
     FIG. 4 is a cros-ssectional side elevation view of the apparatus represented by FIG. 3. 
    
    
     DESCRIPTION OF THE DISCLOSED EMBODIMENTS 
     With reference now to the drawing, in both disclosed embodiments of the invention cigarettes 11 are delivered via a feed belt 10 to a supply funnel 12, the direction of movement of the cigarettes along belt 10 being generally transversely with respect to their axes. The cigarettes fed into funnel 12 move downwardly, under the influence of gravity, to the entrance end of a shaft 13. The shaft 13 is divided into a plurality of individual guide channels 15 by partition walls 14. Each of the guide channels 15 has a width commensurate with the diameter of the cigarettes being packaged and a length which corresponds to the length of the cigarettes being packages. Accordingly, the cigarettes 11 will be arranged individually one above another in the channels 15 as shown. Plural vibrating rollers 16 are positioned at the entrance ends to the channels 15 to assist the delivery of the cigarettes into the channels. Pairs of aligned sensors 17, which extend through the side walls of shaft 13, are associated with each of guide channels 15. The sensors 17 are located just above the exit ends of the channels 15 and are positioned such that cigarettes moving down the channels will successively assume a position where they are axially in line with the sensors as may best be seen from FIGS. 2 and 4. The sensors 17 will be optical devices of a type known in the art for checking the degree of filling of the cigarettes and will provide electrical output signals commensurate with defective cigarettes. 
     In the embodiment of FIGS. 1 and 2, a transfer wheel 18 is located immediately beneath the shaft 13. The transition wheel 18 is provided, in its periphery, with groups of receiving grooves or troughs 19. The number of receiving grooves 19 in each group will correspond to the number of guide channels 15 in shaft 13 and the grooves 19 will be spaced apart by a distance commensurate with the spacing between the exit ends of the channels. The depth of the receiving grooves 19 corresponds to the diameter of the cigarettes 11. In the disclosed embodiments, there are four separate groups of seven receiving grooves 19. The lower end of shaft 18, which in part defines the exit ends of the channels 15, is shaped to be complimentary to the convex peripheral surface of the transfer wheel 18 whereby each cigarette passing from the shaft 13 into a groove in the transition wheel 18 will travel the same distance. The transfer wheel 18 is coupled to a stepping drive, not shown. In the disclosed embodiment, the transfer wheel 18 will be indexed in steps of 90 degrees each by the stepping drive. 
     In the disclosed embodiments, the transfer wheel 18 is indexed in steps of 90 degrees in the counter-clockwise direction. After one step, the last filled group of grooves 19 will be in registration with an array of ejectors 20. Through the use of logic circuitry which receives the outputs of the sensors 17, the ejectors will be selectively activated to cause the ejection of defective cigarettes from grooves 19 during the period between steps when the transfer wheel is stationary. The ejectors 20 can be mechanical push-type devices or pneumatic ejectors which employ a jet of compressed gas to blow defective cigarettes from the grooves 19. 
     Cigarettes which are not defective remain in the grooves 19 and, when the transfer wheel 18 has been indexed a second 90 degree step, will fall into a supply funnel 21 which is positioned beneath transfer wheel 18. Funnel 21 provides communication with a shaft 24 which, like shaft 13, is subdivided into an array of parallel guide channels 23 by means of partition walls 22. The number of guide channels 23 will typically be commensurate with the number of cigarettes which are to form the layer of a &#34;block&#34; to be wrapped. Also, the lower or exit ends of the channels 23 will be positioned closely adjacent to one another and arranged that the axes of the cigarettes disposed thereon will be parallel. As indicated in FIG. 2, the cigarettes will be removed layer-by-layer, from shaft 24 by a pusher-type device 25. Vibrating rollers 26 are provided at the entrance ends to the channels 23 to facilitate the even distribution and the separation of the cigarettes 11 so that they enter the guide channels 23 individually. 
     A filling-level controller 32 is associated with the supply funnel 21 for shaft 24. The transfer wheel 18 will be activated to deliver cigarettes to funnel 21 whenever the controller 32 senses that there are an insufficient number of cigarettes within funnel 21 to ensure adequate supply for the wrapping machine via the shaft 24. Thus, under normal operation, the supply funnel 21 will remain partly filled with cigarettes of acceptable quality. 
     Apparatus in accordance with the embodiment of FIGS. 1 and 2 includes a retention device which has been indicated generally and schematically at 27. The purpose of the retention device 27 is to support the lowest level of cigarettes in the plural guide channels 15 after a group of cigarettes has been transferred from the guide channels into the grooves 19 in transfer wheel 18. Accordingly, the retention device 27 functions to prevent the feed of cigarettes to the transfer wheel as it moves during steps and thus ensures that the grooves 19 are not filled successively from the first of the guide channels 15 encountered during the counter-clockwise movement of the transfer wheel. Restated, the retention device 27 guarantees that there will be transfer only from all of the channels 15 substantially simultaneously into the grooves 19 on the transfer wheel 18. 
     The retention device 27 may take the form of a fork-shaped lever 28 which is pivoted about a pivot pin or axle 29. The side edges of the lever 28 which cooperate with the descending cigarettes is curved so as to have a radius which approximates that of transfer wheel 18. Lever 28 is pivotal between a position in which the curved sides thereof rest against the underside of the shaft 13, and thus close the exit ends of the guide channels 15, and a position in which the lever is pivoted away from the underside of shaft 13, thus opening the exit ends of the guide channels and permitting the transfer of cigarettes from all of the guide channels into the receiving grooves 19 on transfer wheel 18. It has been found desirable to separate the groups of receiving grooves 19 from one another by a circular arc, as indicated at 30, having a length which corresponds to the length of that portion of a circle which encompasses a group of the receiving grooves 19. If the arcuate portions 30 are shortened, in order to reduce the diameter of the transfer wheel 18, it is necessary to design the lever 28 so that it closes the exit ends of the guide channels 15 progressively rather than simultaneously. 
     As an alternative construction, the retention device 27 can be in the form of circular segments, which may be fork-shaped, corresponding in number to the number of groups of receiving groups 19 on the transfer wheel 18. These circular segments will be spring biased toward the axis of rotation of transfer wheel 18 and will be camed outwardly such that, during the indexing of the transfer wheel 18, the circular segment passing into the region of the exit ends of the guide channels 15 is caused to move outwardly against the spring bias to a position where it is aligned with the outer periphery of the transfer wheel and thus closes the guide channels 15. The caming arrangement will be such that, when the transfer wheel reaches its stationary position between steps, where the guide grooves will be aligned with the exit ends of the guide channels 15, the circular segment which has been cammed outwardly will be released so that it will move back to its retracted initial position under the influence of the spring bias. The retraction of the circular segment will, in the same manner as the pivoting of the lever 28 of the embodiment of FIGS. 1 and 2, permit a simultaneous transfer from all of guide channels 15 into the guide grooves 19. 
     As a further alternative to the fork-shaped retention device 27 of FIGS. 1 and 2, it is possible to employ a single arcuate segment which is rotatable in a direction which is opposite to the direction of rotation of the transfer wheel 18 by a distance, i.e. length of a circular arc, which corresponds to the length of the circular arc defined by a group of the receiving grooves 19. Such a single arcuate segment will then be rotated with transfer wheel 18, and in registration with its outer periphery, to a position beneath shaft 13 and the segment will then be rotated back to an initial position to permit the transfer from the guide channels 15 into the grooves 19. 
     During their movement with the transfer wheel 18, the cigarettes 11 are mechanically retained in the receiving grooves 19 by a wall 31 which is in the form of a circular arc extending from shaft 13 to funnel 21. However, it is to be noted that the receiving grooves 19 in transfer wheel 18 may be provided with apertures which are connected to a vacuum pump whereby the cigarettes will be held in the grooves 19 by suction. If the cigarettes are retained by suction in the grooves 19, it is possible to selectively interrupt the connection between the vacuum pump and the apertures in the grooves thereby allowing acceptable cigarettes to be released where they will fall into funnel 21 and retaining the defective cigarette in the grooves until a desired release point, either upstream or downstream of funnel 21, is reached. Obviously, if the cigarettes are held in grooves 19 by suction, it is possible to eliminate the ejectors 20. 
     In the embodiment of FIGS. 3 and 4, the shaft 13 and the funnel 21 are not in vertical alignment as is the case in the embodiment of FIGS. 1 and 2. Thus, in the embodiment of FIGS. 3 and 4 there is an offset, which is preferably approximately the same distance as the length of the cigarettes being packaged, at the interface between the guide channels 15 and the transfer wheel 18. The shaft 13 is provided with a bottom which defines an arc corresponding to the arc defined by the bottoms of the grooves 19 in the transfer wheel 18. The shaft 13 is also open at the opposite sides adjacent the bottom thereof. A reciprocal slide 33, which also has an arcuate shape, is arranged to enter the base of shaft 13 through the open sides and to engage the lowermost cigarettes 11 in the guide channels 15 to push them into registered guide grooves 19 on the transfer wheel 18, this pushing action being to the right as the apparatus is depicted in FIG. 4. The embodiment of FIG. 4 has the advantage that, when the transfer wheel 18 is indexed, the cigarettes in the grooves 19 do not contact the lowermost cigarettes in the guide channels 15, the downwardly directed force being commensurate with the weight of the number of cigarettes in each guide channel. Other than not employing a retention device 27, the embodiment of FIGS. 3 and 4 includes the same components and operates in the same manner as the embodiment of FIGS. 1 and 2. 
     It is to be noted that the number of guide channels 15 in the shaft 13 may be made greater than the number of guide channels 23 in the shaft 24 in the interest of slower rotation of the transfer wheel 18. Also, if the funnel 21 has the appropriate width, two transfer wheels 18, which cooperate with respective shafts 13, can be employed. Use of a pair of transfer wheels 18 increases the time which is available for the quality control procedure, i.e. the examination of the cigarettes by means of sensors 17 and the subsequent ejection of defective cigarettes. 
     It is to be understood that the present invention is not limited to the embodiments described and shown herein, which are deemed to be merely illustrative of the best modes of carrying out the invention, and which are susceptible to modification as to form, composition and details of operation. The invention rather is intended to encompass all such modifications which are within its spirit and scope as defined by the claims.