Abstract:
A cigarette packing machine has a first drive normally transmitting motion to packing units which are employed to advance a series of arrays of cigarettes or other rod-shaped articles of the tobacco processing industry and to confine each array in a discrete packet by providing each of successive arrays of the series with one or more envelopes, labels and the like. The first drive is decelerated and brought to a halt in the event of malfunctioning of one or more packing units of the machine and/or for other reasons, and this initiates or prevents an interruption of operation of at least one second drive which transmits motion to one or more packing units during deceleration and/or during a period following stoppage of the first drive. The second drive(s) causes or cause the respective packing unit(s) to complete operations which, if not carried out prior to restarting of the first drive, would entail the making of numerous defective packets.

Description:
CROSS-REFERENCE TO RELATED CASES 
     This application claims the priority of commonly owned German patent application Serial No. 199 47 709.4 filed Oct. 4, 1999. The disclosure of the above-referenced German patent application, as well as that of each U.S. and foreign patent and patent application identified in the specification of the present application, is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     The invention relates to a method of and to an apparatus for packing discrete commodities, for example, commodities which constitute arrays of parallel rod-shaped articles (such as plain or filter cigarettes) of the tobacco processing industry. More particularly, the invention relates to improvements in methods of and in apparatus for packing arrays of cigarettes or the like wherein a drive is utilized to operate various units of the packing machine until the machine receives or generates a stop signal which initiates a stoppage of the drive. 
     An apparatus of the above outlined character is disclosed in published German patent application Serial No. 21 15 505 of Kruse et al. The apparatus comprises a first drive which advances a series of successive arrays of plain or filter cigarettes along an elongated path in stepwise fashion. Successive arrays receive blanks which are converted into envelopes surrounding the respective arrays. Each step of the method which can be carried out by resorting to such apparatus can begin while the array is in motion and can be completed during the immediately following interval of stillstand of the array. If the apparatus receives a signal which initiates a stoppage of the first drive, such signal does not entail immediate stoppage of all units which form part of the packing apparatus and participate in the making of successive finished packs each of which contains an array of rod-shaped articles. Instead, various units of the packing apparatus remain operational to thus ensure that certain packing or wrapping operations are completed before all units of the apparatus come to a standstill. This is desirable and advantageous because any prolonged stoppage of an array which is on its way along a path defined by a standard packing apparatus is likely to result in drying or setting of adhesive which is utilized to position various panels, walls, flaps, tucks and/or other foldable parts of successive converted blanks; therefore, the packets or envelopes constituted by such blanks are defective and must be discarded together with their contents. 
     Otherwise stated, the German patent application of Kruse et al. proposes to terminate various packing operations which must be completed without delay in order to turn out a satisfactory pack (such as a so-called soft pack or a so-called hinged-lid pack) which can be confined in a carton and/or otherwise processed rather than being dumped into a receptacle or onto a take-off conveyor for the gathering of defective packs. 
     The published German patent application of Kruse et al. further discloses that, in addition to the first drive (which serves to advance a series of successive arrays stepwise into and along a first path), the packing apparatus can employ a second drive which serves to supply blanks along a second path and into a selected portion of the; first path, as well as a third drive which is put to use subsequent to the generation of a stop signal and the ensuing stoppage of the first and/or second drive. The operations of such drives are regulated by a control circuit which ensures that the apparatus can complete a series of successive operations in order to achieve a reduction of the number of rejects. The control circuit is set up to ensure that the apparatus completes a series of treatments upon each constituent of a partly finished (future) pack so that the completion of partly finished packs can be carried out upon renewed starting of the drives. 
     A drawback of the aforediscussed conventional packing method and apparatus is that the number of rejects which are turned out during deceleration of the first drive and during operation of the second drive is still high or very high. Moreover, the aforediscussed prior proposal does not encompass the manipulation of all packing units which are likely to cause the making of unsatisfactory final products, such as packs of plain or filter cigarettes, cigars, cigarillos and/or other rod-shaped smokers&#39; products. Furthermore, the control circuit which is proposed by Kruse et al. is rather complex and expensive. 
     OBJECTS OF THE INVENTION 
     An object of the present invention is to provide a method of packing arrays of cigarettes or the like or other types of commodities into envelopes of metallic foil, transparent plastic sheet stock, cardboard, paper and/or other wrapping materials in such a way that the number of rejects caused by a stoppage of the packing apparatus is well below that turned out by resorting to presently known methods. 
     Another object of the invention is to provide a method of reducing the cost of recovering tobacco from defective packs or boxes of plain or filter cigarettes or other smokers&#39; products. 
     A further object of the invention is to provide a method which renders it possible to salvage partially finished packs of cigarettes or other rod-shaped smokers&#39; products which are, being turned out or processed by a packing apparatus subsequent to the generation of a signal serving to initiate deceleration and eventual stoppage of the packing apparatus. 
     An additional object of the invention is to provide a method which renders it possible to reduce the number of rejects caused by decelerations and stoppages of a packing apparatus to a small fraction of the number of rejects being turned out under such circumstances by presently known packing apparatus including those disclosed in the published German patent application Serial No. 21 15 505. 
     An additional object of the invention is to provide a method which renders it possible to achieve substantial savings in metallic foil and/or other wrapping materials for arrays of rod-shaped smokers&#39; products or other types of commodities. 
     Still another object of the invention is to provide a novel and improved packing apparatus for the practice of the above outlined method. 
     A further object of the invention is to provide a packing machine or apparatus with novel and improved means for driving various packing units including that or those serving to advance or transport arrays of rod-shaped smokers&#39; products as well as those serving to supply and to manipulate blanks for conversion into envelopes or other constituents of packets for arrays of rod-shaped smokers&#39; products. 
     Another object of the instant invention is to provide a packing machine or apparatus which can be utilized with equal advantage to achieve reductions in the numbers of defective packs or other types of containers for block-shaped commodities due to any and all known causes of deceleration and stoppage of a packing machine. 
     An additional object of the invention is to provide a packing machine or apparatus which exhibits the above-enumerated features and advantages and can be incorporated in presently known production lines for the making and processing of rod-shaped smokers&#39; products as a superior substitute for presently known packing apparatus. 
     SUMMARY OF THE INVENTION 
     One feature of the present invention resides in the provision of a method of packing successive arrays of a series of arrays of rod-shaped articles of the tobacco processing industry. The improved method comprises the steps of employing at least one first drive to carry out a plurality of consecutive packing operations upon each of successive arrays of the series, generating at times (i.e., when necessary) signals each of which entails a deceleration and ensuing stoppage of the at least one first drive, and utilizing at least one second drive to carry out (at least in part) at least one of the packing operations during an interval covering at least one of (a) the deceleration, (b) the deceleration and a period of the ensuing stoppage, and (c) a period of the ensuing stoppage of the at least one first drive. 
     The packing operations can include the following steps: advancing successive arrays of the series along a predetermined path, and confining each array in at least one envelope in a predetermined portion of the path. The advancing step preferably comprises moving the arrays stepwise. 
     Alternatively, the packing operations can include the steps of advancing successive arrays of the series along a predetermined path, supplying to a portion of the predetermined path blanks for conversion into envelopes for successive arays, applying an adhesive to selected portions of the blanks, converting the blanks into envelopes surrounding the respective arrays, and withdrawing successive arrays and the respective blanks from the predetermined path. The converting step can include folding the blanks around the respective arrays. 
     The step of utilizing at least one second drive can include employing at least one differential gear. 
     The employing step can include resorting to a first drive which is arranged to rotate a first output element (such as a shaft) at a first RPM prior to the signal generating step, and the utilizing step can comprise utilizing at least one second drive which is arranged to rotate a second output element (e.g., a shaft) at a second RPM which at most matches the first RPM. 
     The method can further comprise the step of synchronizing the operation of the first drive with the operation of the at least one second drive. 
     Another feature of the present invention resides in the provision of a machine or apparatus for packing successive arrays of rod-shaped articles of the tobacco processing industry. The improved apparatus comprises a primary driving arrangement including at least one first drive, a plurality of mobile packing units which receive motion from the at least one first drive and are arranged to provide each of the series of arrays with at least one envelope, means for generating at times signals each of which entails a deceleration and ensuing stoppage of the at least one first drive, and a secondary driving arrangement including at least one second drive which is arranged to transmit motion to at least one of the packing units during an interval covering at least one of (a) the deceleration, (b) the deceleration and a period of ensuing stoppage, and (c) a period of ensuing stoppage of the first drive. 
     For example, the arrays can consist of quincunx formations of rod-shaped articles. 
     The improved, apparatus can further comprise means for separably coupling the at least one first drive with the at least one second drive. 
     The at least one second drive can comprise one or more differential, gears. 
     The at least one packing unit is or can be one of a plurality of, packing units including means for supplying to successive arrays of the series of arrays blanks for conversion into envelopes for the respective arrays, means for applying to selected portions of the blanks one or more, films of hotmelt or another suitable adhesive substance, means for converting blanks into envelopes, and means for evacuating packed arrays (i.e., finished packs). 
     If the at least one packing unit is one of a plurality of units including means for supplying to successive arrays of the series blanks for conversion into envelopes for the respective arrays, the secondary driving arrangement can comprise a plurality of second drives including a drive for the blank supplying means. 
     If the packing units include at least one means for supplying to successive arrays foldable blanks for conversion into envelopes for the respective arrays and folding means which is operable to drape the blanks around the respective arrays, the at least one second drive can include means for operating the folding means. Such folding means can include at least one rotary or otherwise movable folding member. 
     The at least one first drive can comprise at least one rotary first driving member which is rotatable at a plurality of different speeds, and the at least one second drive can comprise at least one second driving member which is rotatable at a plurality of different speeds; such packing apparatus can further comprise means for synchronizing the speed of the at least one first driving member with that of the at least one second driving member. 
     The improved packing apparatus can further comprise means for assembling rod-shaped articles into the aforementioned series of successive arrays. 
     The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved packing 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 partly schematic perspective view of a packing apparatus for arrays of plain or filter cigarettes which embodies one form of the present invention; and 
     FIG. 2 is a coordinate system wherein the RPMs of rotary members of the first and second drives are measured along the ordinate and the times are measured along the abscissa. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIG. 1 shows a twin-track packing machine or apparatus for, the making of so-called hinged-lid packs  130  each of which is assumed to contain an array of 19 or 20 plain or filter cigarettes, cigars, cigarillos or other rod-shaped articles of the tobacco processing industry, e.g., in the so-called quincunx formation. The following part of this description will refer, for the sake of simplicity and convenience, to arrays of cigarettes; however, it is to be understood that the improved method can be practiced, and the improved apparatus can be utilized, with equal or similar advantage, for the packing of all or practically all types of rod-shaped smokers&#39; products as well as for the packing of many other types of successive block-shaped commodities which are to be confined in single or plural envelopes made of paper, metallic foil, cardboard, transparent plastic sheet material or the like. 
     FIG. 1 shows only those constituents of the twin-track packing apparatus which are deemed to be necessary for a full understanding of all aspects of the present invention. 
     The reference character  100  denotes a unit which serves to assemble arrays of cigarettes in a manner well known in the art of cigarette packing machines. One presently known packing apparatus or machine which employs an assembling unit of the type shown at  100  is known as COMPAS  500  packer and is distributed by the assignee of the present application. The illustrated assembling unit  100  comprises three hoppers  101  which supply layers of cigarettes into the receptacles of an endless conveyor  102  serving to, advance empty receptacles into the range of the first hopper  101  which deposits therein a first layer of cigarettes, thereupon into the range of a second hopper which inserts a second layer of cigarettes so that the cigarettes of the second layer are parallel to but laterally offset relative to the cigarettes of the first layer, and thereafter into the range of the third hopper which delivers a third layer of cigarettes in such a way that the cigarettes of the third layer are parallel to the cigarettes of the first and second layers but are laterally offset relative to the cigarettes of the second layer. This completes the assembly of successive arrays which are thereupon delivered into two elongated paths at a transfer station  104  for stepwise advancement or transport past a series of packing units each of which carries out at least one of a series of operations necessary to provide each array with one or more envelopes and to thus form a series of finished hinged-lid packs 
     The first packing unit  105  is designed to provide successive arrays in the two tracks with first or inner envelopes which can constitute converted blanks of a metallic foil, e.g., tinfoil. Each blank is draped around the respective array to constitute the outer envelope of a partially finished pack  106 . 
     The next step includes advancement of successive partly finished packs  106  into the range of a second packing unit including one or more rotary and/or otherwise movable deforming or folding tools  108  for the application and deformation of preformed collars  107  of the type customary in hinged-lid packs. 
     A further packing unit includes a conveyor  111  which delivers a discrete second blank  110  (e.g., a cardboard blank) to a station where one or more rotary and/or otherwise movable folding tools  109  convert the second blanks  110  into outer envelopes each of which surrounds a partly finished pack  106  and the respective collar  107 . Each second blank  110  which reaches the respective path for successive partly finished packs  106  must be provided with one or more films of a suitable adhesive coating those portions (such as walls, panels, flaps, tucks or the like) of the respective second blanks  110  which must be bonded to the adjacent walls, panels or like parts in order to advance or complete the making of finished packs  130 . The adhesive can be a hotmelt and/or a cold-bonding glue. It is customary to apply adhesive films to the lateral flaps  112  of the blanks  110  so that such flaps are compelled to adhere to the adjacent sidewalls of the thus obtained outer envelopes. 
     The thus obtained converted partly finished packs  106  (each of which is partly surrounded by a collar  107  and is further surrounded by a partly converted cardboard blank  110 ) are thereupon introduced into the receptacles of a rotary wheel-shaped conveyor  113  which comprises and/or cooperates with means for completing the conversion of blanks  110  into outer envelopes of hinged-lid packs  130 . The thus obtained packs  130  dwell in the receptacles of the rotary wheel-shaped conveyor  113  for periods of time which are necessary to complete the setting of the adhesive (such as cooling of the hotmelt) so that the packs  130  retain their desired sizes and shapes, i.e., that the parts which are bonded to each other by films of adhesive cannot move relative to each other. As a rule, the adhesive which is utilized in one or more packing units of the improved apparatus is a hotmelt or a cold-bonding adhesive. 
     The last packing unit of the illustrated apparatus comprises drying columns or shafts  114  wherein the packs  130  remain until advanced to the next apparatus or machine of a production line, e.g., to a machine known as C  90  film wrapper which confines each pack  130  in a transparent film constituting a third or outermost envelope and can be provided with a customary tear strip or tape. The C  90  film wrapper can deliver successive packs to a machine known as B  90  cigarette pack boxer which confines groups of normally ten packs in cardboard boxes known as cartons. The C  90  and B  90  machines are distributed by the assignee of the present application. 
     The reference characters A to D denote various stations of the improved packing apparatus. Thus, the array forming station A accommodates the assembling unit  100  and its hoppers  101 . The station B accommodates the means ( 105 ) for supplying and folding blanks (such as precut sheets of metallic foil) which can form the inner envelopes of the packs  130  (i.e., the envelopes of the partially finished packs  106 ). The station C accommodates the unit or units (such as  108 ,  109 ,  111 ) for the supplying and folding of second blanks  110 , and the station D provides room for the packing unit including the wheel-shaped conveyor  113  and the associated means for completing the conversion of blanks  110  into the outer envelopes of the finished packs  130 . 
     The apparatus of FIG. 1 further comprises a primary driving arrangement which includes a single or composite first drive  103 . The illustrated drive  103  comprises a first part  120  which transmits motion to a toothed belt  115  and hence to one or more conveyors  115 A serving to advance two files of arrays from the station A to the station B. The first drive  103  further serves to transmit motion to mobile constituents of the assembling unit  100  at the; station A. A second part  121  of the first drive  103  transmits motion to the folding members  107 ,  108  and to other mobile parts at the station C, and a third part  122  of the first drive  103  transmits motion to the wheel-shaped conveyor  113  and to other mobile parts at the station D (FIG. 1 shows that the third part  122  of the first drive  103  transmits motion to the respective driven parts by way of two toothed belts  115   a ,  115   b ). The belt  115   a  receives motion from a transmission  123  which, in turn, receives motion from a rotary output shaft  103 A of the first drive  103  and drives a conveyor  115   a′  for the partly finished packs advancing into the range of the wheel-shaped conveyor  113 . The belt  115   b  at the station D receives motion from a transmission  124  which is driven by the shaft  103 A and drives the conveyor  113 . 
     The apparatus of FIG. 1 further comprises a signal generator  103 B which is operatively connected with one or more sensors (not specifically shown) which cause the signal generator  103 B to transmit to the first drive a stop signal serving to decelerate and eventually stop the first drive. For example, the signal from the signal generator  103 B can be processed at  103 B to arrest or to no longer drive the moving parts at the stations A to D upon elapse of two or three successive cycles of the packing operation. Each such cycle includes a first part during which the conveyor  115 A is in motion and a second part during which the conveyor  115 A is at a standstill. 
     In accordance with heretofore known proposals, the various units of conventional packing apparatus come to a halt upon completion of a preselected number of cycles following the transmission of a stop signal by the signal generator. Such signal is generated in response to faulty operation of one or more packing units, in response to detection of malfunctioning of one or more makers serving to supply cigarettes to the assembling unit  100 , in response to detection of malfunctioning of the machine or machines receiving finished packs  130  from the station D, and/or for any other compelling reason which warrants temporary stoppage of a modern high-speed cigarette packing apparatus. 
     The just discussed stoppage of all packing units in a standard packing machine or apparatus entails the making of huge quantities of rejects due to the failure of already applied films of adhesive to bond or to adequately bond neighboring parts of the blanks (such as the blanks corresponding to those shown, at  110 , in FIG.  1 ). Moreover, the just described mode of operation of conventional packing apparatus renders it necessary to discard large numbers of blanks which are already provided with films of adhesive but cannot be converted into finished envelopes within two or three cycles following the transmission of a signal (such as a defect signal) by the signal generator(s) of the conventional packing apparatus. 
     Still further, conventional packing apparatus turn out additional rejects which are constituted by partially finished packs (such as those shown at  106  in FIG. 1) because, when a conventional packing apparatus is restarted (e.g., (upon elimination of the defect(s) of one or more packing units), partially finished packs already located in the path or paths leading from the source (such as  100 ) of arrays to the outlet of the conventional packing apparatus are brought into contact with blanks carrying already dried or partially dried films of adhesive so that such blanks cannot be converted into satisfactory envelopes. For example, if a blank  110  which carries one or more films of activated adhesive remains on the conveyor  111  for a certain period of time subsequent to the application of adhesive thereto, such blank cannot be converted into an envelope which properly confines the respective partially finished pack  106 . 
     In accordance with the method of the present invention, the numbers of rejects can be reduced to a significant extent in that the improved packing apparatus is provided with a secondary driving arrangement which, in the apparatus of FIG. 1, comprises two second drives  125  and  126 . The drive  125  can transmit motion to the transmission  123  and hence to the moving parts driven by the toothed belt  115   a  at the station D. The drive  126  can transmit motion to the transmission  124  and hence to the wheel-shaped conveyor  113  and associated moving parts at the station D (by way of the respective toothed belt  115   b ). 
     At least one of the second drives  125 ,  126  can constitute a differential gear (also called differential). These drives cooperate to complete the bonding of various parts of the blanks  110  to each other and to the representative collars  107  (if necessary) prior to setting of adhesive films carried by such blanks. The second drive  125  and/or  126  can be set in operation during the interval of deceleration of the first, drive  103  to zero speed, or during such deceleration and a following interval of idleness of the drive  103 , or only during such interval of idleness. This will depend upon the nature of the adhesive coating selected for use on part of the blanks  110  and/or upon the duration of deceleration of the first drive  103  from normal operating speed to zero speed. At any rate, the arrangement is preferably such that those lateral flaps  112  of the blanks  110  which carry films of still active adhesive, or which are to adhere to such films of adhesive, are properly bonded to the neighboring parts of the respecting blanks  110  and the adhesive films have set before the second drive  125  and/or  126  is brought to a halt. For example, the drives  125 ,  126  can be brought to a halt when the wheel-shaped conveyor  113  is empty, i.e., when all of the packs located downstream of the station B are confined in the drying unit  114 . 
     The transmission  123  can also constitute a differential gear. The control circuit of the improved apparatus can decelerate (disconnect) the transmission  123  prior to renewed starting of the first drive  103 , and such control unit can start the second drive  125  to ensure that the, blanks  110  which are advanced by the restarted first drive  103  are already provided with freshly applied adhesive films so that the packing apparatus can turn out satisfactory packs  130  as soon as the first drive  103  is restarted. The interval of operation of the second drive  125  is preferably selected in such a way that the path for the advancement of adhesive-carrying blanks  110  from the paster to the folding members  108 ,  109  is filled with blanks  110  carrying films of fresh adhesive before the first drive  103  is restarted. 
     The second drive  125  and/or  126  can be on while the first drive  103  is on, as long as the second drive(s) does or do not interfere with the operation of the packing apparatus prior to generation of a stop signal by the signal generator  103 B. It is particularly desirable to ensure that the adhesive applying unit or units be brought to a timely halt in response or subsequent to the generation of a stop signal for the first drive  103 , and that such adhesive applying unit(s) be started in good time prior to restarting of the drive  103  (i.e., during the interval of idleness of the conveyor  115 A). Thus, it is highly advisable to ensure that those lateral flaps of the blanks  110  which have already advanced beyond the respective adhesive applying unit or units be caused to adhere to the adjacent panels of the outer envelopes (converted blanks  110 ) prior to stoppage of the packing unit including the folding member  108  and/or  109 , as well as that the blanks  110  be set in motion prior to restarting of the first drive  103  to thus ensure that each partly finished pack  106  which comes into contact with a blank  110  upon restarting of the drive  103  will be confined in a blank  110  which carries films of adhesive prior to setting of such adhesive. Otherwise stated, each partly finished pack  106  which is set in motion in response to restarting of the first drive  103  should form part of a satisfactory pack  130 . 
     The above also applies for the wheel-shaped conveyor  113 , i.e., this conveyor should be driven (by the second drive  126 ) until all of the packs in its receptacles can retain their desired shapes at the time of entry into one of the drying units  114 . 
     Thus, the second drives  125 ,  126  can be set to operate during deceleration of the first drive  103 , during deceleration of the drive  103  and during the immediately following period of idleness of the drive  103 , and preferably also for a selected period of time preceding restarting of the drive  103 . 
     Though FIG. 1 shows a multiple-track packing apparatus, the invention can be embodied with equal advantage in single-track packing apparatus. An advantage of a multiple-track packing apparatus is that the number of rejects is reduced to a greater extent than in a single-track packing apparatus. 
     Furthermore, though the packing apparatus of FIG.  1  is set up to operate in stepwise fashion, it is also possible to employ an apparatus wherein the arrays are in continuous motion. An advantage of the illustrated intermittently operated packing apparatus is that the shift from operation with the first drive  103  to operation with the second drive(s)  125  and/or  126  (or vice versa) is simplified. 
     In accordance with a presently preferred embodiment, the secondary driving arrangement comprises second drives which are designed to operate (when necessary) the blank feeding unit  111 , the paster or pasters for the blanks  110 , the folding member  108  and/or  109 , and/or the conveyor  113 . This renders it possible, in a manner as fully described hereinbefore, to complete the application of adhesive films to a requisite number of blanks  110 , to complete the assembly of such blanks with the partly finished packs  106 , and to evacuate the thus obtained finished packs  130  from the conveyor  113 , i.e., into the drying unit  114 , after the adhesive sets so that the condition (such as configuration) of the respective finished packs  130  remains unchanged and matches the desired (optimum) configuration. 
     It is further within the purview of the present invention to expel from the improved packing apparatus those blanks  110  which cannot be converted into satisfactory outer envelopes of finished packs  130 . Such blanks can include those blanks which have received films of adhesive paste but cannot be converted into satisfactory outer envelopes of packs  130  subsequent to the generation of a stop signal for the first drive  103 . The ejection of selected blanks  110  from the improved packing apparatus can be carried out by resorting to suitable pneumatic ejector(s) which becomes or become active at the time of generation of a stop signal for the first drive  103  or upon elapse of a preselected interval of time following such signal generation. 
     Still further, it is possible to operate the paster or pasters for the blanks  110  in such a way that a blank which is about to be advanced into the range of the folding member  107  or  108  is provided with a fresh film of adhesive (e.g., over a previously applied and already hardened or set film) prior to conversion of the respective blank into the outer envelope of a finished pack  13 . 
     In accordance with a modification, the second drive  125  can be set in motion in response to the generation of a stop signal for the first drive  103 , and such second drive then ensures that at least one of the folding members  107 ,  108  remains operative during gradual deceleration of the drive  103  and/or during a period of complete stoppage of the drive  103 . This ensures the conversion of at least some of the partly finished packs  106  into finished packs  130  with resultant savings in blanks  110  and/or tobacco to be recovered from unsatisfactory packs  130 . 
     Though the utilization of differential gears as second drives  125 ,  126  and/or as transmissions  120 ,  121 ,  122 ,  123  and/or  124  is preferred at this time, other types of second drives and/or transmissions can be utilized with equal or similar advantage. Differential gears are preferred in many instances because their utilization entails savings in initial cost and contributes to simplicity and reliability of the control unit which is employed in the improved packing apparatus. 
     An advantage of a secondary driving arrangement which employs a plurality of discrete second drives (such as  125  and  126 ) is that it is possible to operate such second drives independently of or in synchronism with each other. Substantial savings in blanks  110  and/or a reduction of the number of defective packs  130  can be achieved when the second drive or drives controls or control at least one folding member ( 107  or  108 ) and at least one conveyor, for delivery of blanks (such as the conveyor  111  for the blanks  110 ). 
     In the coordinate system of FIG. 2, the RPMs of rotary output elements (such as shafts) of the first drive  103  and of the second drive  125  and/or  126  are measured along the ordinate, and the durations of intervals or periods of operation of various drives are measured along the abscissa. 
     The RPM of the shaft (such as  103 A) which receives motion from the first drive  103  is denoted by the curve  200 , and the RPM of the output shaft of one of the drives  125 ,  126  (e.g., of the output shaft  125 A of the second drive  125 ) is denoted by the curve  201 . The signal generator  103 B transmits a stop signal at the instant t 1  and the deceleration of the shaft  103 A from maximum or normal RPM to zero RPM takes place during the interval between the instants t 1  and t 3 . The drive  125  is started (e.g., by the signal generator  103 B or by the aforementioned control circuit) at the instant t 2  and the RPM of its shaft  125 A increases from zero to its maximum value at the same rate at which the RPM of the shaft  103 A decreases between the instants t 2  and t 3 . The broken line  202  denotes an RPM which is the sum of RPMs of the shafts  103 A,  125 A during the interval between the instants t 2  and t 3 . Thus, the operation of parts at the station D takes place at a rate which is also denoted by the curve  202 , and such operation can proceed beyond the instant t 3 , i.e., beyond the instant of actual stoppage of the first drive  103 . 
     The second drive  125  and/or  126  is started prior to restarting of the drive  103  and is brought to a halt at the exact moment of restarting the drive  103  or with a preselected delay subsequent to such restarting. The second drive(s) need not be actually arrested, as long as it or they is or are disconnected from the respective transmission  123  and/or  124  in good time for smooth transition from transmission of motion by the second drive  125  and/or  126  to renewed transmission of motion by the first drive  103 . 
     It has been found that the improved packing apparatus and the method which can be practiced by resorting to such apparatus render it possible to greatly reduce the number of rejects (defective packs) and the number of blanks which must be discarded. It is further clear that additional savings can be achieved by providing a (third) second drive for the transmission  122  which drives the folding member  109  (the transmission  122  of such packing apparatus can constitute and preferably constitutes a differential gear). The same applies for the transmission  121  which drives the folding member  108 . The provision of a second drive for each of the transmissions  121 ,  122 ,  123 ,  124  entails a pronounced reduction of the number of rejects. 
     It is advisable to select the normal RPM of the shaft  103 A in such a way that it at least equals but can exceed the RPM of the shaft receiving motion from the second drive  125  or  126 . This renders it possible to turn out satisfactory packs  130  (with properly glued converted blanks  110 ) even in the event of a malfunction, e.g., in the event of a malfunction which necessitates the generation (by  103 B) of a stop signal for the first drive  103 . All that is necessary is to select the RPM of the output element of the second drive  125  and/or  126  in such a way that all adhesive-carrying blanks  110  can be converted into finished outer envelopes of packs  130  prior to setting of adhesive films on such blanks  110 . The operation of the control unit (which can be installed in or with the signal generator  103 B) for the drives  103 ,  125 ,  126  can be selected in such a way that the operations of the first and second drives can be synchronized with a view to ensure that the deceleration of various units of the packing apparatus and the restarting of such units can be carried out in an optimum manner as far as the quality of finished packs  130  and/or the number of rejects is concerned. 
     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 packing machines for cigarettes and other commodities and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the appended claims.