Abstract:
Apparatus for transporting cartons of cigarette packets or analogous block-shaped commodities employs an indexible turret which advances a series of successive equidistant commodities along an arcuate horizontal path into the inlet of a straight horizontal second path defined by an elongated reach of an endless belt conveyor. The conveyor carries spaced-apart receptacles each defined in part by an outwardly extending retaining element affixed to the belt conveyor, and in part by a two-armed lever which is pivotably mounted on the conveyor and is biased by one or more springs to an idle position in which the respective receptacle can receive a commodity from the turret during travel past the inlet of the second path. A commodity which is in the process of entering a receptacle at the inlet bears upon one arm of the lever against the spring bias to thus move the other arm to a position in which the other arm cooperates with the retaining element to advance the commodity along the second path. The other arm and the retaining element cooperate with one or more fixed rails to confine the commodity in a filled receptacle to movement along the second path.

Description:
CROSS-REFERENCE TO RELATED CASES 
     This application claims the priority of German patent application Serial No. 199 07 579.4 filed Feb. 23, 1999. The disclosure of the above-referenced German patent application, as well as that of each U.S. and foreign patent and patent application mentioned in the specification of the present application, is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to transporting apparatus in general, and more particularly to improvements in apparatus for transporting discrete commodities along a first path, from the first path into a second path, and along the second path. Typical examples of commodities which can or which must be transported in an apparatus of the type to which the apparatus of the present invention belongs are block-shaped objects such as packets containing plain or filter cigarettes or other rod-shaped articles of the tobacco processing industry and/or so-called cartons which contain predetermined numbers of packets. 
     It is already known to transport cartons of cigarette packets along a first path having an outlet which is inclined relative to the inlet of a second path. The second path is defined by or is adjacent a transporting unit having a series of discrete receptacles each of which can receive at the outlet of the first path at least one carton for advancement along the second path, e.g., to a station where sets of cartons are introduced into discrete boxes or to a station where the cartons are draped into envelopes of paper or other suitable wrapping material. Each receptacle comprises at least two spaced-apart carton-engaging elements at least one of which is movable toward and away from the other engaging element, namely between a position in which a carton can readily enter into or leave the receptacle and a position in which the carton is reliably held in the receptacle for the purpose of advancing along the second path. 
     Conventional apparatus of the just outlined character are often employed in apparatus wherein cigarette packets, cartons of cigarette packets or other block-shaped commodities must be supplied to, transferred at and advanced from a transfer station with a high degree of accuracy and predictability. For example, the first conveyor which supplies block-shaped commodities to the transfer station can constitute an indexible turret, and the second conveyor which receives successive commodities of a series of successive commodities from the turret can include or constitute an endless belt, band or chain conveyor. The latter can be provided with a set of equidistant receptacles in the form of pockets destined to accept and to transport discrete commodities each of which can constitute a carton confining a number of properly distributed or arrayed cigarette packets or the like. 
     Published German patent applications Serial Nos. 43 00 149 A1 and 195 32 092 A1 disclose transporting apparatus of the above outlined character. The receptacles of the second conveyor are provided with pairs of mobile jaws which are shiftable by disc cams and/or other types of cams in order to ensure that a receptacle can receive a commodity while it advances along the inlet of the second path and that such receptacle can thereupon retain the commodity in a desired position during advancement along and toward the outlet of the second path. The movements of the jaws must take place with a rather high degree of accuracy for a number of reasons, namely to ensure predictable entry of successively delivered commodities into the receptacles or pockets of the second conveyor (i.e., an entry which does not entail damage to—such as deformation of—the commodities), to ensure the advancement of commodities with the respective receptacles in optimum positions for predictable evacuation, and to ensure predictable and rapid transfer of commodities from their receptacles upon arrival at the outlet of the second path. Furthermore, successive commodities should not collide with each other and they should not jam the transfer station between the outlet of the first conveyor (such as the aforementioned turret) and the inlet of the second conveyor. 
     A drawback of the apparatus which are disclosed in the aforementioned published German patent applications is that the controls for the mobile jaws of the receptacles are very complex, expensive and prone to malfunction. Furthermore, such complex controls necessitate frequent inspection, adjustments, cleaning and/or other time-consuming maintenance work during which the apparatus, or an entire production line employing such transporting apparatus, is idle with attendant huge losses in output. Moreover, the controls take up substantial amounts of space which is at a premium in a modern cigarette making and/or processing (such as packing) plant. 
     OBJECTS OF THE INVENTION 
     An object of the invention is to provide a novel and improved apparatus wherein the changes in the condition of receptacles (e.g., changes in the size and/or shape of the receptacles) do not necessitate the utilization of any automated and/or other complex equipment. 
     Another object of the invention is to provide an apparatus wherein the commodities which must leave a first conveyor or transporting unit for the purpose of entering the receptacles of a second conveyor or transfer unit are caused to share all movements of the respective receptacles in a novel and improved way. 
     A further object of the invention is to provide the receptacles with novel and improved means for triggering a reduction in the sizes of the respective receptacles when such receptacles reach optimum positions for reception of commodities in the form of cigarette packets, cartons containing sets of cigarette packets or other substantially block-shaped commodities. 
     An additional object of the invention is to provide a production line which embodies one or more apparatus of the above outlined character. 
     Still another object of the invention is to provide an apparatus wherein the conveyed commodities can perform certain important functions which contribute to simplicity, reliability, compactness and reduced cost of the improved apparatus. 
     A further object of the invention is to provide a novel and improved method of transferring block-shaped commodities from a first path into a different second path at a high frequency, without damage to the commodities, and with a pronounced reduction of rejects. 
     SUMMARY OF THE INVENTION 
     The invention is embodied in an apparatus for transporting commodities, such as so-called cartons which contain soft or hinged-lid packets of plain or filter cigarettes or other rod-shaped smokers&#39; products. The improved apparatus comprises a first transporting unit including guide means defining a first path having an inlet. The first transporting unit further includes driven receptacles which are movable along the first path in a predetermined direction past and beyond the inlet, and each receptacle comprises a plurality of commodity engaging elements including first and second elements. At least one of the first and second elements is movable relative to the other of the first and second elements between a first position in which the receptacle can accept a commodity and a second position in which a commodity being received in the receptacle is compelled to move with the receptacle along the first path beyond the inlet. The improved apparatus further comprises a second transporting unit including second guide means defining a second path having a portion arranged to deliver successive commodities of a series of commodities to the inlet of the first path. The aforementioned portion of the second path and the inlet of the first path are oriented to permit entry of commodities from the second path into a receptacle at the inlet of the first path in the first position of the respective at least one engaging element. Each receptacle further comprises means for effecting a movement of the at least one engaging element of such receptacle at the inlet of the first path toward the other engaging element of the receptacle in response to impingement upon by a commodity at the aforementioned portion of the second path. 
     It is clear that, instead of serving as cartons for packets of plain or filter cigarettes or the like, the commodities which can be manipulated by the improved apparatus can constitute other types of block-shaped objects preferably having at least substantially identical sizes and shapes. 
     The inlet of the first path and the aforementioned portion of the second path preferably make an acute or an obtuse (i.e., an oblique) angle. 
     The first and second engaging elements of each receptacle can be (and preferably are) spaced apart from each other, and the movement effecting means of each receptacle preferably includes means for moving the at least one engaging element toward the other engaging element of such receptacle. The arrangement is or can be such that the at least one engaging element of each receptacle is movable relative to the other engaging element in and counter to the predetermined direction; such movement takes place while the respective receptacle is located at the inlet of the first path. 
     Each receptacle can be constructed, assembled and mounted in such a way that its movement effecting means is movable by a commodity at the inlet of the first path from an idle position to an operative position to thus effect the aforementioned movement of the at least one engaging element toward the other engaging element of such receptacle. The apparatus preferably further comprises hold-down means for maintaining the commodity which has moved the movement effecting means at the inlet to the operative position in engagement with the respective movement effecting means; such hold-down means can form part of the guide means which defines the first path. The hold-down means is arranged to engage the commodity in the first path at or at least downstream of the inlet (as seen in the predetermined direction). It is presently preferred to employ a stationary hold-down means which defines a portion of the first path. 
     The hold-down means and the receptacle (or each of several receptacles) advancing along the first path define a chamber for a commodity in the first path; the hold-down means and the movement effecting means of the receptacles in the first path face each other and confine the commodities in such receptacles to movement along the first path. 
     In accordance with a presently preferred embodiment, the hold-down means comprises at least one elongated stationary rail along which successive commodities slide during movement along the first path. 
     The apparatus (e.g., each receptacle) preferably further comprises means for mechanically coupling the at least one element of each receptacle to the respective movement effecting means. For example, the at least one element of each receptacle can be mounted for pivotal movement relative to the guide means of the first transporting unit. The means for mechanically coupling can be designed in such a way that the at least one engaging element of each receptacle is rigidly connected with the respective movement effecting means. For example, each receptacle can comprise a lever which is pivotable relative to the guide means of the first transporting unit; each such lever can include a first arm constituting the at least one element and a second arm constituting the movement effecting means of the respective receptacle. Each such receptacle can further comprise a fulcrum for the respective lever, and the arm of each lever can extend at least substantially at right angles to the axis of the respective fulcrum. Each of the levers can be mounted for pivotal movement about a substantially horizontal axis. Moreover, the pivot axes of the levers are or can be at least substantially normal to the predetermined direction. The first arms of the levers can be at least substantially normal to the respective second arms. For example, each first arm can be provided with a first commodity-contacting surface, and each second arm can be provided with a second commodity-contacting surface which is at least substantially normal to the first surface. 
     The first and second engaging elements of each receptacle are, or can be, at least substantially parallel to each other in the second position of the at least one element of the respective receptacle. 
     The first and second engaging elements of each receptacle can be provided with commodity-contacting surfaces which are at least substantially parallel to each other and are at least substantially normal to the predetermined direction in the second position of the respective at least one engaging element. Such commodity-contacting surfaces can constitute at least substantially plane surfaces which are at least substantially parallel to each other while in contact with a commodity in the first path. Furthermore, such commodity-contacting surfaces can be at least substantially normal to the first path (i.e., to the predetermined direction) while in contact with a commodity in the first path. 
     The second path is or can constitute an arcuate path and can be located in a predetermined (e.g., at least substantially horizontal) plane. As already mentioned hereinbefore, the first and second entraining elements of each of the receptacles can constitute the arms of a lever which is pivotable about an axis extending at least substantially at right angles to the predetermined plane. The second path can constitute a circular path (or a portion of a circular path), and the second transporting unit which defines such second path can constitute an indexible turret, e.g., an upright turret. 
     The first transporting unit can constitute or form part of an endless belt or band or chain conveyor. The first path can constitute a straight path, and the first and second entraining elements of a receptacle in the first path are (or can be) located one behind the other (as seen in the predetermined direction). Each of the receptacles is preferably arranged to accept at least one commodity during advancement of the respective first and second entraining elements along the inlet of the first path. 
     The endless conveyor is or can be indexed in synchronism with the turret conveyor. 
     The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved apparatus itself, however, both as to its construction and the modes of assembling and operating the same, together with numerous additional important and advantageous features and attributes thereof, will be best understood upon perusal of the following detailed description of certain presently preferred specific embodiments with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a fragmentary schematic side elevational view of a transporting apparatus which embodies one form of the present invention, an elongated block-shaped commodity being confined and held in a receptacle at the inlet of the first path and additional commodities being confined and held in the receptacles located downstream of the inlet; 
     FIG. 2 is a plan view of that portion of the apparatus which is shown in FIG. 1; 
     FIG. 3 a  is an enlarged view of a detail of the structure shown in FIG. 1, a commodity being shown during the last stage of indexing of the second transporting unit in a direction to introduce such. commodity into an empty receptacle at the inlet of the path defined by the guide means of the first transporting unit; 
     FIG. 3 b  shows the structure of FIG. 3 a  but with a commodity already received and about to be locked in the receptacle at the inlet of the first path; and 
     FIG. 3 c  shows the structure of FIG. 3 b  but with the commodity fully received and also locked in the receptacle at the inlet of the first path. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     The apparatus which is shown in the drawings is designed for the transport of elongated block-shaped commodities each of which can constitute a so-called carton containing an array of, for example, ten packets of plain or filter cigarettes or other rod-shaped articles of the tobacco processing industry. Such commodities (hereinafter called cartons for short) can be turned out by a machine known as B90 or G90 (both distributed by the assignee of the present application), and the improved apparatus can serve to transport a series of successive cartons from a B90 or G90 machine directly to a boxing machine which confines groups of cartons in boxes (e.g., to a so-called CP 90 case packer (distributed by the assignee of the present application) or to machine which confines successive cartons in films of transparent plastic material (e.g., a machine which is known as Pewo-Fold overwrapper and is also distributed by the assignee of the present application). 
     The drawings merely show a small fraction of a long series of successive cartons including a foremost carton  2  which is on the way, e.g., to a CP 90 case packer, a second carton  2   a  which is also in the process of being advanced to the case packer, a third carton  2   b  at a transfer station  18  between a first or foremost transporting unit or conveyor  20  of the improved apparatus and a second or rear transporting unit or conveyor  4 , and a fourth carton  2   c  (shown in FIGS. 3 a  to  3   c ) which is supported by the conveyor  4  and is in the process of advancing toward the transfer station  18 . However, it is clear that the improved apparatus can be designed for the transport of other types of commodities, for example, soft or hinged-lid packets of plain or filter cigarettes or other rod-shaped articles of the tobacco processing industry as well as commodities which have nothing in common with the making of smokers&#39; products. 
     The illustrated second conveyor  4  is a turret conveyor which is indexible about the horizontal axis of a shaft  8 . The shaft  8  carries three equidistant discs  6  having peripheral surfaces provided with radially inwardly extending recesses  10  for portions of cartons. Each of the illustrated discs  6  is provided with four equidistant recesses  10 , and each recess  10  of any given disc  6  registers with a recess  10  of each other disc. The dimensions of all recesses are identical and each such recess has a rectangular outline correponding to that of a carton  2  or  2   a  or  2   b  or  2   c , and so on. 
     The carton  2   b  is received in those recesses  10  of the three discs  6  which are about to reach (see FIGS. 3 a  and  3   b ) or are already located at the transfer station  18  (see FIGS. 1,  2  and  3   c ). The carton  2   c  has portions received in those recesses  10  of the three discs  6  which immediately follow the recesses  10  confining portions of the carton  2   b . Successive cartons of the series (i.e., those following the carton  2   c ) are preferably inserted into those recesses  10  which are located at the three o&#39;clock positions of the respective discs  6  (as seen in FIG.  1 ). 
     The dimensions of the recesses  10  are preferably selected in such a way that a carton is snugly received therein during transport along a circular path in a direction indicated by the arrow A. The cartons are inserted radially inwardly toward the axis of the shaft  8  and are held by the discs  6  against undesirable movement radially or axially of the shaft  8  during indexing from the inlet of the conveyor  4  toward the transfer station  18 . A carton (see the carton  2   b  in FIGS. 1,  2  and  3   c ) which has arrived at the transfer station  18  is extracted from the respective recesses  10  of the three discs  6  while moving radially of and away from the axis of the shaft  8 . 
     It is clear that the number of discs  6  can be changed without departing from the spirit of the invention (as long as the thus modified conveyor  4  can properly coact with the conveyor  20  to ensure reliable transfer of cartons from the circular path defined by the conveyor  4  into a preferably straight path defined by the guide means of the conveyor  20 ). Furthermore, the conveyor  4  can be modified if the conveyed commodities are not cartons. 
     The conveyor  4  comprises guide means for maintaining the cartons  2   b ,  2   c  and the next-following cartons in the arcuate (preferably circular) path ending at the transfer station  18 . Such guide means includes the radially outer portions of the discs  6  and an arcuate shroud  12  which can extend all the way from the station where the recesses  10  accept successive cartons of a short or long series of cartons and on to the transfer station  18 . The shroud  12  can constitute a stationary piece of suitably configurated sheet metal, and the dimensions and mounting of this shroud are such that the turret including the shaft  8  and the discs  6  can be readily indexed (in the direction indicated by the arrow A) and that succesive cartons  2   b ,  2   c , etc. can reach the transfer station  18  and can be transferred into the straight first path defined by the guide means of the conveyor  20  in the direction indicated by the arrow B. 
     The transporting unit  20  is a conveyor employing one or more endless flexible elements  22  in the form of belts, bands or chains. The illustrated conveyor  20  employs two endless flexible elements (hereinafter called belts for short) one of which is located between the planes of the upper and median discs  6  (as seen in FIG. 2) and the other of which is located between the planes of the median and lower discs  6  (again as seen in FIG.  2 ). The upper reaches or stretches  22   a  of the belts  22  form part of the aforementioned guide means which ensures that successive cartons  2 ,  2   a , etc. remain in the straight path during movement in the direction of arrow B from the transfer station  18  toward the locus of transfer of cartons from the conveyor  20 , e.g., to a wrapping station or to a boxing station. The other constituent of the guide means for the cartons being advanced by the conveyor  20  includes three lower guide rails  34  (see FIG. 2) and at least one upper guide rail  36  (shown only in FIG.  1 ). The guide rails  34  flank the cartons from below during advancement in the direction indicated by the arrow B, and the guide rail or rails  36  flanks or flank such cartons from above in a manner as shown in FIG.  1 . 
     The belts  22  are toothed belts and are trained over at least two pulleys (one shown in each of FIGS. 1 and 3 a  to  3   c , as at  23 ). The pulleys  23  which define the righthand end turns of the belts  22  are located in the spaces between the neighboring pairs of discs  6  so that the upper reaches of these belts are located beneath the recesses  10  confining portions of a carton ( 2   b  in FIGS. 3 a  and  3   b ) which is in the process of being delivered to the transfer station  18 . The means for indexing the shaft  8  and for intermitently driving the pulleys  23  can comprise two discrete electric or other suitable stepping motors (not shown). FIG. 2 shows that the belts  22  are spaced apart from the respective pairs of discs  6  so that the belts can be driven while the turret of the conveyor  4  is idle and vice versa. 
     In accordance with a novel and important feature of the present invention, each belt  22  carries a set of equidistant holding means or receptacles  32  (hereinafter called receptacles for short) of identical sizes and shapes. The receptacles  32  are mounted and assembled in such a way that they are located at the outer (upper) sides of the upper reaches  22   a  while advancing from the transfer station  18  (i.e., from the inlet of the path defined at least in part by the guide members  34  and  36 ) in the direction indicated by the arrow B and on to the outlet (not shown) of such path. Each receptacle  32  comprises two spaced apart carton engaging elements in the form of jaws or holders  24   a ,  30  and means  24   b  for effecting a movement of at least one jaw ( 24   a ) toward the other jaw ( 30 ) when the respective receptacle is located at the inlet of the path defined by the conveyor  20 , i.e., at the transfer station  18 . 
     The jaw  24   a  and the respective movement effecting means  24   b  (hereinafter called trigger for short) constitute two arms of a bell crank lever  24  which is fulcrumed at  26  on the respective belt  22 . The arms  24   a ,  24   b , the jaw  30  and the pintle  26  which defines the fulcrum for the lever  24  are normal to the direction indicated by the arrow B when the respective receptacle  32  is located at the transfer station (inlet)  18 . The arm (jaw or engaging element)  24   a  has a preferably plane surface which confronts a complementary plane surface of the jaw  30 , and such plane surfaces are parallel to each other when the respective receptacle  32  is located in the path defined by the conveyor  20  and its chamber  33  receives a portion of a carton (such as the carton  2   b  shown in FIGS. 1 and 3 c ). When a receptacle  32  is located at the transfer station  18 , the arm  24   a  of its lever  24  extends at least substantially vertically upwardly and the trigger or arm  24   b  then extends at least substantially horizontally and rearwardly, i.e., in a direction toward the jaw  30  (counter to the direction indicated by the arrow B). 
     Each lever  24  is biased in a counterclockwise direction (as viewed in FIG. 1) by a torsion spring  28  which is coiled around the pintle  26  and has a first leg reacting against the respective belt  22  and a second leg bearing upon a pin carried by the respective jaw  24   a . Other types of resilient means can be employed with equal advantage as long as they ensure that the aforementioned plane surfaces of the jaws  24   a ,  30  of the receptacle  32  at the transfer station  18  define a chute or an analogous downwardly narrowing pathway for predictable entry of an approaching (descending) carton ( 2   b  in FIG. 3 a ) into the chamber  33  of such receptacle. The jaws  30  of the receptacles  32  are rigidly connected to (e.g., of one piece with) the respective belts  22 . Each jaw  30  can constitute a plate-like external projection of the respective belt  22  and is normal to the direction indicated by the arrow B during advancement of the respective receptacle and a portion of a carton (such as  2  or  2   a  or  2   b ) therein along the horizontal path defined by the guide means  34 ,  36 . 
     Each chamber  33  is open from above when the respective receptacle  32  is located at the transfer station  18 , and such chamber is then bounded by the aforementioned plane surfaces of the jaws  24   a ,  30  as well as by a portion of the upper side of the upper reach or stretch  22   a  of the respective belt  22 . Actually, the underside of such chamber is bounded by the upper side of the respective trigger  24   b  which is then located in the path of downward movement of a descending carton (such as the carton  2   b  shown in FIGS. 3 a  and  3   b ). Each of the FIGS. 3 a  to  3   c  merely shows a single receptacle  32 ; however, and as can be seen in FIG. 1, each of the belts  22  carries a set of equidistant receptacles  32 . 
     As can be seen in FIG. 2, each of the lower guide means  34  registers with one of the three discs  6  and each thereof has an upper side extending in the direction of the arrow B. The rear end portions of the guide means  34  are spaced apart from the respective discs  6  so that they cannot interfere with the descent of a carton (such as  2   b ) into the two receptacles  32  then located at the inlet of the path defined by the conveyor  20 , i.e., at the transfer station  18 . The upper sides of the guide means  34  are flush with the upper sides of the upper reaches  22   a  so that they can slidably support portions of the carton  2   b  when the latter is properly received in the receptacles  32  dwelling at the station  18 . While the carton  2   b  approaches (i.e., descends toward) the station  18 , the upper sides of the triggers  24   b  then disposed at such station are located slightly above the upper sides of the guide means  34  so that the descending carton  2   b  must pivot the respective levers  24  against the opposition of the respective torsion springs  28  during downward movement between the then mutually inclined confronting plane surfaces of the jaws  24   a ,  30 . 
     The upper guide means  36  can comprise one, two or more guide rails which serve as hold-down means for the cartons (such as the cartons  2  and  2   a  shown in FIG. 1) then located in the path defined by the conveyor  20 . FIG. 1 shows that the right-hand end portion of the guide rail  36  shown therein has an underside which slopes downwardly toward the passage between the two guide means  34 ,  36  to thus ensure predictable entry of successive cartons into the path between the guide means  34 ,  36 . The distance between the underside of the upper guide means  36  and the upper side of the lower guide means  34  equals or slightly exceeds the height of a carton so that the upper guide means  36  prevents the torsion springs  28  in the first path from dissipating energy at such times when the plane surfaces of the jaws  24   a  in the channel between the guide means  34 ,  36  should be parallel with the plane surfaces of the respective jaws  30 . In accordance with a presently preferred embodiment, the apparatus (and more specifically the conveyor  20 ) comprises lower guide means  34  composed of three equidistant parallel rails, and upper guide means  36  also comprising three elongated equidistant guide rails each of which is coplanar with one of the lower guide rails. 
     FIG. 1 shows that the right-hand portions of the lower guide rails  34  are spaced apart from the transfer station  18  and that the lower end portion of the shroud  12  terminates at the level of the undersides of the upper guide rails  36 ; all this constitutes additional safety or precautionary undertakings to ensure predictable transfer of successive cartons from a set of three aligned recesses  10  into two receptacles  32  at the transfer station  18  even though the portion of the second path at the transfer station  18  is inclined relative to the inlet of the first path. 
     The mode of operation of the improved apparatus, with emphasis upon the mode of transferring cartons from the recesses  10  into the receptacles  32 , is as follows: 
     The prime mover which indexes the conveyor  4  is set to turn the shaft  8  through angles of 90° and in a counterclockwise direction (as indicated by the arrow A shown in each of FIGS. 1 and 3 a  to  3   c ). The means for driving the pulleys  23  for the belts  22  is set to advance the belts through distances corresponding to that between two neighboring jaws  30 ; the pulleys  23  are set to rotate in a counterclockwise direction (as viewed in FIG. 1) so that the upper reaches  22   a  of the belts  22  are caused to move in the direction indicated by the arrow B. A suitable control circuit (not shown) is employed to synchronize the operation of the prime mover for the shaft  8  with the operation of the prime mover for the pulleys  23  in such a way that two aligned empty receptacles  32  (one on each of the belts  22 ) are located at the transfer station  18  (i.e., at the inlet of the path which is defined by the guide means  34 ,  36  of the conveyor  20 ) not later than when a carton ( 2   b ) approaches the transfer station (see FIG. 3 a ). 
     As already mentioned above, the inlet of the arcuate path defined by the guide means (including the shroud  12 ) of the conveyor  4  is preferably located diametrically opposite the transfer station  18 , i.e., a carton which has been introduced into three aligned recesses  10  at the inlet of the arcuate path must be indexed twice (through 90° angles) in order to enter two aligned receptacles at the inlet of the straight path. The exact construction of the means for introducing cartons into the recesses  10  of the conveyor  4  forms no part of the present invention; such means can form part of the aforementioned Pewo-Fold overwrapper. 
     When the carton  2   b  reaches the position which is shown in FIG. 3 a , it is located rather close to but still away from the transfer station  18 . The conveyor  4  is still in motion and two receptacles  32  are already located at the inlet of the straight path, i.e., at the station  18 . FIG. 3 a  shows only one of these receptacles  32 ; the other receptacle is located in front of or behind the illustrated receptacle. The lever  24  of FIG. 3 a  is biased by the respective torsion spring  28  so that the plane surface of the arm or jaw  24   a  is not parallel to the plane surface of the jaw  30 , and the plane upper side of the trigger  24   b  of the lever is located at a level above the upper sides of the upper reaches  22   a , i.e., above the level of the upper sides of the three lower guide rails  34 . At such time, the conveyor  20  is at a standstill and the two receptacles  32  at the station  18  are in optimum positions to accept the oncoming carton  2   b . The belts  22  are provided with or carry suitable stops (not specifically shown in the drawings) which ensure that the springs  28  can dissipate energy only until the respective levers  24  assume angular positions corresponding to that of the lever shown in FIGS. 3 a  and  3   b . This enables the,triggers  24   b  at the station  18  to-extend into the respective chambers  33 , i.e., into the path of movement of the oncoming carton  2   b . At the same time, the jaw  24   a  of the receptacle  32  shown in FIG. 3 a  is located outside of the broken-line circle  38  denoting the path of movement of two radially outermost portions  2   b ′ of the carton  2   b . Of course, and as actually shown in FIG. 1, if the depth of the recesses  10  is selected to match or even exceed the corresponding dimension of a carton, the radially outermost portions  2   b ′ are located at the peripheries or radially inwardly of the peripheries of the discs  6 ; the plane surface of the jaw  24   a  shown in FIG. 3 a  is then tangential (or can be tangential) to the peripheral surfaces of the discs  6 . All that counts is to select the positions of the aforementioned stops (which limit the extent to which the springs  28  can dissipate energy) in such a way that the (retracted) jaws  24   a  at the transfer station  18  cannot prevent the underside of the descending carton  2   b  from reaching and depressing the triggers  24   b.    
     FIG. 3 a  further shows that the jaw  30  of the receptacle  32  at the transfer station  18  is held in a position in which it permits unimpeded entry of the radially innermost portion of the carton  2   b  into the pocket  33  of such receptacle. 
     FIG. 3 b  shows that stage of indexing of the conveyor  4  which follows the stage shown in FIG. 3 a . The lower portion of the carton  2   b  has already entered the chamber  33  of the receptacle  32  and is about to contact (or already contacts) the plane upper side or surface of the trigger  24   b . By way of example, the angular position of the conveyor  4  must be changed through two additional degrees in order to complete the respective indexing step, i.e., to move the carton  2   b  to the position shown in FIGS. 1 and 3 c . This last stage of indexing of the conveyor  4  causes the underside of the carton  2   b  to pivot the lever  24  from the angular position of FIG. 3 a  or  3   b  to the angular position of FIG. 3 c . The underside of the carton  2   b  then lies flush against the upper side of the trigger  24   b  and also flush against the horizontal upper sides of the three lower guide rails  34 . The spring  28  of FIGS. 3 a  to  3   c  is caused to store energy (or to store additional energy) so that it can return the respective lever  24  to the angular position of FIG. 3 a  or  3   b  as soon as the carton  2   b  is removed from the conveyor  20 . 
     While pivoting (clockwise) from the angular position of FIG. 3 a  or  3   b  to the angular position of FIG. 3 c , the trigger  24   b  causes the jaw  24   a  of the respective lever  24  to pivot in the same direction and to thus cause at least some shifting of the carton  2   b  radially inwardly toward the shaft  8  of the conveyor  4 . This, in turn, causes the jaws  24   a  and  30  to clamp the respective portion of the carton  2   b  between them so that the carton is held against movement relative to the belts  22  in and counter to the direction indicated by the arrow B when the conveyor  20  is thereupon-set in notion to advance the carton by a step away from the transfer station  18 . While moving in the direction of arrow B, the carton  2   b  is received in the chambers  33  of two receptacles  32  and lies flush against the plane surfaces of two jaws  24   a , two jaws  30  and two triggers  24   b , as well as against the undersides of the guide rails  36  and against the upper sides of the guide rails  34 . On its way from the transfer station  18 , the carton  2   b  advances beneath the adjacent lowermost portion of the shroud  12  and beneath the adjacent chamfered right-hand end portions of the upper guide rails  36 . The three recesses  10  which served to deliver the carton  2   b  to the station  18  are aligned with the cartons  2  and  2   a , and the shaft  8  is or can be indexed again as soon as the carton  2   b  is fully withdrawn from such recesses in response to starting of the conveyor  20  in a sense to advance the cartons  2 ,  2   a  and  2   b  in the direction of the arrow B. 
     As already mentioned above, the upper guide rails  36  further serve as a hold-down means in that they prevent the springs  28  from returning the levers  24  along the upper reaches  22   a  of the belts  22  to the angular positions (with reference to the belts) corresponding to those of the levers shown in FIGS. 3 a  and  3   b . The guide rails  36  can perform such functions because the height of the passage between the upper sides of the lower rails  34  and the undersides of the upper rails  36  is at least close to the corresponding dimensions of the carton  2 ,  2   a ,  2   b  and so on. However, the springs  28  are free to dissipate at least some energy as soon as the cartons reach the outlet of the path defined by the guide rails  34 ,  36  so that each lever  24  which returns to the transfer station  18  is again in an optimum position to permit entry of a carton in a manner as described above with reference to FIGS. 3 a ,  3   b  and  3   c.    
     The extent of pivotal movement of each trigger  24   b  between its idle (FIGS. 3 a ,  3   b ) and operative (FIGS. 1 and 3 c ) positions can be readily selected in such a way that, once the trigger is depressed by a carton in the chamber  33  of the respective receptacle, such carton is held with a requisite force to prevent any undesirable movements relative to the belts  22  during advancement along the straight path defined by the conveyor  20 . Since the movements of the trigger  24   b  between idle and operative positions are effected by the cartons (i.e., by the commodities which are to be transported by the improved apparatus), this contributes significantly to simplicity, reliability, versatility and lower cost of the apparatus. Furthermore, the apparatus can readily compensate for unavoidable minor departures of the dimensions of transported cartons from ideal dimensions. Still further, the apparatus can prevent undesirable localized deformation of conveyed cartons, e.g., under excessive bias of the springs  28 , because the combined upper guide rails and hold-down means  36  limit the extent of required pivoting of the levers  24  and maintain the upper sides of the triggers  24   b  in angular positions in which the upper sides lie flush against the underside of the respective carton. 
     It is clear that the triggers  24   b  need not be of one piece with the respective jaws  24   a . All that is necessary is that the mechanical connection between the trigger  24   b  and the jaw  24   a  be sufficiently reliable to guarantee proper engagement and retention of the carton (such as  2   b ) which is in the process of arriving at the transfer station  18 . 
     Still further, the apparatus can be modified by providing each receptacle  32  with a plurality of mobile jaws. For example, the jaws  30  can be replaced by jaws which are suitably coupled (e.g., by link trains) to the respective triggers  24   b  so that each of the several mobile jaws is pivoted, shifted and/or otherwise moved into engagement with the freshly arrived carton as soon as the carton engages and pivots and/or otherwise displaces the trigger. 
     In the illustrated apparatus, the shaft  8  is horizontal and the discs  6  are caused to rotate in vertical planes, However, it is also possible to employ a vertical shaft  8  and provide the shaft with a requisite number of horizontal discs  6 . The illustrated embodiment, wherein the axes of the pintles  26  are normal to the planes of the discs  6 , is preferred at this time. The discs  6  introduce a carton into the receptacles  32  at the transfer station  18  in such direction and in such orientation that the weight of the transferred carton also contributes to retention of the triggers  24   b  in optimum positions in which the triggers ensure that the jaws  24   a  bear upon the adjacent external surface of the carton at the station  18  with a force which is required to ensure that the carton is forced to bear against the adjacent side or surface of each of the jaws  30  at the transfer station and thereupon in the passage between the upper guide rails  36  and the lower guide rails  34 . 
     The illustrated apparatus can be modified still further by replacing one-piece jaws  24   a  and/or  30 , and/or one-piece triggers  24   b , with composite jaws and/or triggers. Furthermore, the carton-contacting surfaces of the jaws  24   a ,  30  and/or triggers  24   b  can be treated (e.g., coated with suitable linings) in such a way that the surfaces can engage and hold the adjacent portions of a carton with a requisite amount of friction. This further enhances the reliability of transport of the cartons along the path which is defined by the conveyor  20 , i.e., in the passage between the upper guide rails  36  and the lower guide rails  34 . The carton contacting surfaces of such guide rails can be treated to a finish which ensures that the frictional engagement between the guide rails and the adjacent sides of the cartons being compelled to advance along the first path is reduced to a minimum. 
     Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic and specific aspects of the above outlined contribution to the art of apparatus for transporting block-shaped commodities or the like and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the appended claims.