Abstract:
A conveyor apparatus includes first and second conveyors for moving products from a receiving station to a first transfer station and a plurality of product-carrying elements mounted on the conveyors. The product-carrying elements of the first and second conveyors form respective first and second groups of product-carrying elements. The products are conveyable from the receiving station to the first transfer station alternatingly by the two conveyors. A first discharge mechanism at the first transfer station includes a plurality of product-pushing elements for displacing products transversely to the advancing direction. The product-pushing elements are spaced identically to the spacing of the product-carrying elements. A third conveyor extends from the first transfer station to a second transfer station. Receiving elements are mounted on the third conveyor for carrying containers from the first transfer station, where products are placed into the containers by the product-pushing elements, to the second transfer station.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the priority of Swiss Application No. 1156/98 filed May 26, 1998, which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     International Application WO 96/41760 describes an apparatus for conveying products to a packing machine. The apparatus has two parallel, separately driven endless conveyor chains which carry, along less than one half of their circumferential lengths, carrier elements arranged at uniform distances from one another and extending from the respective chains. The carrier elements advance the products on a slotted slide plate from a receiving station through a work section to a discharge station where the products are packed in a tubular bag. 
     International Application WO 97/42108 describes a similar apparatus in which the two parallel conveyor elements are toothed belts. 
     U.S. Pat. No. 4,577,453 describes a conveyor apparatus which has but a single conveying element and wherein the products are, at the transfer station, first pushed in groups onto a table and are thereafter deposited by separate pushers into a packing container perpendicularly to the discharging direction. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provide an improved conveyor apparatus of the above-outlined type with which packing containers may be charged with products in a rational manner. 
     This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the conveyor apparatus includes first and second parallel-spaced endless conveyors extending from a receiving station to a first transfer station for moving products in an advancing direction from the receiving station to the first transfer station and a plurality of product-carrying elements mounted on the first and second conveyors at a uniform spacing from one another. The product-carrying elements mounted on the first conveyor form a first group of product-carrying elements and the product-carrying elements mounted on the second conveyor form a second group of product-carrying elements. The first and second groups extend over one part of the length of the respective first and second conveyors. A drive moves the first and second conveyors independently from one another such that products are conveyable from the receiving station to the first transfer station alternatingly by the first and second conveyors. A discharge mechanism, situated at the first transfer station, includes a plurality of product-pushing elements for displacing products transversely to the advancing direction away from the product-carrying elements. The product-pushing elements are spaced identically to the spacing of the product-carrying elements. A third conveyor extends from the first transfer station to a second transfer station. Receiving elements are mounted on the third conveyor for carrying containers from the first transfer station, where products are placed into the containers by the product-pushing elements, to the second transfer station 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIGS. 1 and 2 are schematic side elevational views of a preferred embodiment of the invention. 
     FIG. 3 is a schematic end elevational view of a transverse product-discharging device forming part of the preferred embodiment. 
     FIG. 3 a  is a schematic end elevational view of a transverse product-discharging device according to a variant of the FIG. 3 construction. 
     FIG. 4 is a schematic end elevational view of a container-positioning and discharging device-forming part of the preferred embodiment. 
     FIG. 5 is a schematic side elevational view of a further preferred embodiment of the invention. 
     FIG. 6 is a schematic sectional end elevation of yet another preferred embodiment of the invention. 
     FIG. 7 is a schematic side elevation of the structure shown in FIG.  6 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Turning to FIGS. 1 and 2, a supply belt  10  is arranged upstream of a conveyor apparatus  1  as viewed in the direction A in which wafer-like products  12  (such as biscuits) are advanced in a column  11 . The products  12  may be spaced at random from one another. While the conveyor belt  10  is driven to preferably run at constant speed, in case it runs at variable speed, its drive motor is connected with an angular position transmitter which, in turn, is connected with a control device  13  of the apparatus  1 . Above the conveyor belt  10  a product sensor  14  is disposed which measures the dimensions and shape of the product  12  passing thereunder and compares the sensed magnitudes with inputted and/or learned desired values. Such a measuring step determines not only the outer shape (footprint) of the product  12  and its length on the conveyor belt  10 , but also the upper face thereof. In case the deviations from the desired product configuration exceed predetermined tolerances, a signal is directly applied to an ejection unit  15  which pushes the respective product  12  downstream of the sensor  14  in a direction transverse to the conveying direction A from the conveyor belt  10  into a non-illustrated receptacle. The ejection unit  15  may include a pusher  16  which is briefly operated by an actuator  17  or may include a nozzle which emits a short air blast to remove the defective product  12 . Downstream of the ejection unit  15  and immediately upstream of a receiving station  20  of the apparatus  1  a further sensor  18  is arranged which may be an optical barrier operating with reflected light and which, by means of the control unit  13 , ensures an accurate, cycled introduction of the products  12  into the apparatus  1  at the receiving station  20 . 
     The apparatus  1  includes a sheet metal slide  21  and two endless, parallel toothed belts  24 ,  25  supported on end sprockets  22 ,  23  and positioned above the slide  21 . A group  26  of uniformly spaced product-carrying elements  27  extends from each belt  24 ,  25 . The group length is shorter than one-half of the circumferential length of each belt  24 ,  25 . The two sprockets  22  situated at the receiving station  20  are driven by separate motors  28  each having an angular displacement sensor  29 . The motors  28  are controlled by the control apparatus  13  in such a manner that in each instance one product-carrying element  27  arrives immediately in front of a product  12  at the receiving station  20  and a successive, second product-carrying element  27  of the same group  26  arrives immediately behind the product  12 , and such second product-carrying element  27  advances the product  12  on the slide  21 . The motors  28  are controlled in such a manner that at the receiving station  20  in each instance the leading product-carrying element  27   a  of one group  26  adjoins the trailing product-carrying element  27   b  of the other group  26  immediately without an intermediate space as shown in FIG.  1 . The control of the motors  28  may be effected, for example, as described in the earlier-noted International Application WO 96/41760. As soon as the trailing product-carrying element  27   b  of one group  26  engages a product  12  (FIG.  1 ), the corresponding belt  25  is accelerated (FIG. 2) until the group  26  is aligned on the horizontal work portion  31  with the groups  32  of packing containers  33  which are disposed at a transfer station  30  laterally of the slide  21  and parallel thereto. When such an alignment is reached, the belt  25  is stopped and the products  12  of the entire group  26  are simultaneously laterally pushed into the containers  33  by a mechanism to be described later. For maintenance work, the two toothed belts  24 ,  25  may be individually or together pivoted about the axis of the sprocket wheels  22  as illustrated in phantom lines in FIG.  1 . If a pivotal motion about the downstream end sprockets  23  is preferred, then expediently it is the end sprockets  23  which are driven by the motors  28 . 
     FIG. 3 schematically illustrates an exemplary mechanism for pushing out the products  12  at the transfer station  30 . The slide  21  has, at the transfer station  30 , a series of transverse slots  38  spaced identically to the spacing of the product-carrying elements  27 ; in any case, two slots  38  are provided for every intermediate space between adjoining product-carrying elements  27 . An upwardly bent end  39  of a pusher  40  projects through each of the slots  38 . The pushers  40  are affixed to a joint bar  41  which is swingably supported at its opposite ends by two pivotal levers  42 . The two levers  42  are connected rigidly to one another by a joint shaft  43  which extends parallel to the conveying direction A. The levers  42  are pivotal about the axis of the shaft  43 . The bar  41  is rigidly connected with one end of a lever  44  whose other end is jointed to a carriage  45 . The carriage  45  is horizontally shiftably guided on a carriage support  46  which, in turn, is vertically displaceably guided in a housing  47  of the conveyor apparatus  1 . A disk  51  is connected with a shaft  52  which extends parallel to the shaft  43 . During the ejecting motion, a motor  53  rotates the shaft  52  in each instance through one revolution. On the disk  51 , on one side thereof, an eccentric pin  54  is mounted which is coupled with the carriage  45  by means of a link rod  55 . On the opposite side of the disk  51  a cam disk  56  is mounted which, by means of a follower roller  57 , a pivotal two-arm lever  58  and a linkage rod  59 , causes the vertical motion of the carriage support  46 . During the ejection motion, the corresponding belt  25  is at a standstill and the carriage support  46  is in its shown raised position, so that the upwardly bent end  39  of the pushers  40  displaces the column of the products  12  within the group  26  from the product-carrying elements  27  transversely to the conveying direction A into the containers  33  (not shown in FIG.  3 ). The elements  44 ,  45  and  46  as well as  55 - 59  are offset in the axial direction of the shaft  53  in such a manner that the containers  33  have sufficient space adjacent the slide  21 . For executing a return stroke, the carriage support  46  is lowered by means of the cam disk  56  and the lever  58  so that as early as the duration of such a return stroke, the product-carrying elements  27  of one group  26  may be moved away by means of the belt  25  from the region of the transfer station  30 . During the ejection of the products  12  at the transfer station  30 , the products  12  are, at the receiving station  20 , introduced between the product-carrying elements  27  of the second group  26  of the then advancing other belt  24 . The ejecting operation is repeated thereafter for the second group  26 . 
     Instead of the above-described crank and cam disk drive shown in FIG. 3, it is feasible to operate the carriage support  46  and the carriage  45  by linear motors  60 ,  61  as shown in FIG. 3 a.    
     FIG. 4 illustrates the transfer station  30  without the elements  44 - 59  (which are axially offset). At the transfer station  30  on that side of the slide  21  which is oriented away from the pushers  40 , a conveyor member  64  is arranged which is formed of two parallel endless chains  65 , each supported by two end sprockets  66 ,  67 . The two end sprockets  66  and the two end sprockets  67  form respective coaxial sprocket pairs. The sprocket pair composed of the sprockets  66  is driven by a motor  68  having an angular displacement sensor  69 . The motor  68  and the sensor  69  are connected to the control device  13 . Carriers  70  are mounted on the chains  65  and extend uniformly spaced therebetween. Receiving elements  71  for accommodating the packaging containers (trays)  33  are selectively secured to the carriers  70  such that the open end  73  of the containers  33  is oriented at the transfer station  30  approximately horizontally or vertically. In FIG. 4, for purposes of illustration, the receiving elements  71  are shown alternatingly in these two positions. In reality, all receiving elements  71  of the conveyor member  64  are mounted only in the one or in the other orientation. In a first case the groups  74  of products  12  are formed in the containers  33  in such a manner that the edge of each product  12  of the formed groups  74  touches the bottom  75  of the container  33 . In a second case, the flat large surface of one product lies on the container bottom  75 . In the first case, after each ejecting process, the chains  65  are incrementally moved forward one step corresponding to the thickness of the products  12  until the respective containers  33  are filled. Thereafter, a feeding step follows, corresponding to the division of the carrier  70  less the thickness of the groups  74 . In the second case, the chains  65  are advanced in such a manner that the opening  73  at the transfer station  30  in each instance arrives just underneath the upper side of the slide  21 . As soon as the respective container  33  is filled, a feeding step takes place which corresponds to the length of the division (spacing) of the carriers  70 . 
     At the lower sprockets  67  the containers  33  are caught at a transfer station  77  by a group of fingers  78  which project through non-illustrated slots provided in the receiving elements  71 . The filled containers  33  slide on the sloping upper face  79  of the fingers  78  onto a removal conveyor belt  80 . At the upper sprockets  66  the empty containers  33  are introduced into the receiving elements  71  by means of known, non-illustrated means. 
     FIG. 5 illustrates a further embodiment according to which the product-carrying elements  27  are T-shaped as viewed laterally; that is, at their free ends horizontal product-supporting elements  84  extend which fully carry the products  12  from the receiving station  20  to the transfer station  30  and therefore the slide  21  is dispensed with. FIGS. 6 and 7 show a further variant in which the toothed belts  24 ,  25  or the conveyor chains are situated underneath the working section  31 . The product-carrying elements  27  are mounted on carrier bodies  85 ; one group  26  of carrier bodies  85  is secured to the belt  24 , while the other group  26  of carrier bodies  85  is secured to the belt  25 . The carrier bodies  85  have product supporting surfaces  86  on either side of the product-carrying elements  27  (with the exception of the two ends of the groups  26 ). 
     A great extent of flexibility may be achieved with the apparatus according to the invention. The products  12  may be placed into the containers  33  selectively in an edgewise or in a flatly stacked orientation. A modular construction of the apparatus  1  is feasible. The filling of groups  74  into the containers  33  requires only a few steps resulting in a gentle handling of the products  12 . A large output rate of up to 800 pieces per minute may be achieved. A series of packing containers  33  may be simultaneously charged with products. In FIGS. 1,  2  and  5  the containers to be charged with the products are shown as four side-by-side arranged container groups  89 , wherein each group  89  is composed of three interconnected containers  33 . The distance between adjoining containers belonging to different groups  89  is somewhat greater than the container distance within one and the same group  89 . Accordingly, the pusher groups  26  too, are subdivided by the product-carrying elements  27  into three subgroups which are separated from one another by correspondingly thicker product-carrying elements  27   c . These periodically non-uniform intervals between the product-carrying elements  27  are programmed in the control device  13 , so that with signals from the sensor  18 , an angular sensor relating to the drive of the belt  10  and an angular sensor  29 , a cycling of the products  12  between the product-carrying elements  27  is effected in an accurate manner. Thus, in case of a supply rate of the products  12  on the belt  10  of approximately 720 pieces per minute, the clock frequency of the ejection step is 1 Hz. In case of longer group  32  of containers  33  and a longer work section  31  the clock frequency may be further reduced. 
     It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.