Abstract:
Bundles of banknotes are directed singly and in succession along an infeed duct toward a station located at the top of a channel, where they are formed into a block; the channel functions as a guide along which the block is conveyed by means of a companion element, following a predetermined feed path, at the same time as a continuous strip of banding material is fed along a path transverse to this same path. The leading end of the strip is taken up and restrained by a gripper device, and as the block progresses along the channel, the strip is intercepted and forced to wrap around three faces of the block, assuming a U shape, whereupon the leading end is flattened against the remaining face and a further portion of the strip is drawn by a diverter mechanism into overlapping contact with the leading end. The strip is then cut by a knife, leaving a discrete length of which the ends are joined by a heat seal bit to form a band around the block.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a method of banding groups of sheets, in particular banknotes. 
     The invention finds application to advantage in machines by which banknotes are ordered into groups and transferred to a strapper/bander by which at least one band is looped around each single group of notes and made secure. 
     It is well known that banks need to move notable amounts of paper money around on a daily basis, whether central banks by which new banknotes are issued, or trading banks through which the notes are circulated. To this end, banknotes are first sorted into groups and then placed for the purposes of transportation into relative bags or cassettes. 
     To ensure they can be ordered and transported without the risk of breaking up and to prevent their being tampered with, the groups are secured with bands serving to keep the notes together and minimize opportunities for robbery or pilfering. 
     Generally speaking, banknotes are fed singly and in succession into machines of the aforesaid type and, having been examined and sorted according to denomination and/or type, are directed separately toward the outlets of respective channels along which the groups are formed. 
     In this way stacks of single banknotes are formed at each of the outlets, and as the single notes are accumulated and ordered in predetermined numbers, each stack is taken up and transferred to a station at which it will be suitably strapped or banded. 
     Alternatively, still with machines of the type in question, notes that have been checked and sorted beforehand can be fed into the formation channels already bundled and strapped or banded, so that the stacks which form at the outlet of each channel are stacks of bundles rather than of single notes, and these same stacks of bundles are taken up similarly and transferred to the aforementioned strapping or banding station. 
     For the reasons mentioned above, the strapping or banding operation must be fast and accurate and ensure an end product characterized by strength and quality. In the case of central banks, especially, newly printed notes must be handled with extreme care in order to avoid any accidental damage that might prevent their being issued. 
     The prior art embraces machines for strapping and banding banknotes comprising a feed unit by means of which a continuous strip of material decoiling from a respective roll is cast toward a gripper and placer device that moves along a path following the periphery of the group of notes, offering the strip to one side of the group after another and keeping the material tensioned against the notes until the point of engaging further devices which secure and cut the strip, thus bringing the strapping/banding operation to completion. 
     It will be evident that the solution of utilizing an active mechanism to place and tension the strip around the stack of notes is liable to prejudice a correct execution of the wrapping step, especially at the edges of the stack, where an incorrectly controlled tension can have the effect of damaging and/or displacing the notes, should the strip be overtensioned, or on the other hand of rendering the strapping or banding action ineffective if the strip is too slack. 
     The method in question has been found especially unsuitable, especially with regard to correct and uniform tensioning of the strip, when adopted for strapping or banding notably thick or tall stacks consisting in a number of notes greater than that of a standard bundle, or in a plurality of bundles stacked together. 
     Another drawback of such machines is encountered during the operation of making the strip secure, accomplished generally by overlapping the ends and sealing them together. The tensioned state of the strip tends to render the operation difficult. 
     Accordingly, and for the reasons outlined above, machines of the type in question are limited in terms of operating capacity, lacking in precision and not altogether reliable. 
     The object of the present invention is to provide a machine for banding groups of sheets, banknotes in particular, such as will apply the bands swiftly and accurately and produce an end result assuring strength and quality. 
     A further object of the invention is to provide a machine capable of strapping or banding groups of single banknotes and groups of bundled banknotes with equal ease. 
     SUMMARY OF THE INVENTION 
     The stated object is realized according to the present invention in a method for securing at least one band of strip material around a substantially parallelepiped block of sheets, in particular banknotes, which comprises the steps of causing at least one continuous strip decoiling from a roll to advance along a first predetermined path through the agency of first feed means; restraining one end of the continuous strip through the agency of gripping means designed to interact with a leading portion of the strip that coincides with a first end of the band; causing the block of sheets, through the agency of second feed means, to advance along a second path transversely to the first path in such a way as to enter into contact with the strip and, continuing to advance along the second path, cause the strip to decoil further from the roll and bend to a “U” profile; engaging the leading portion of the strip through the agency of bending means and flattening it against a face of the block positioned rearwardmost relative to the direction followed along the second path; drawing the strip into overlapping contact with the first end of the band, through the agency of diverter means located on the side of the second path opposite to the bending means; cutting the strip at the overlap through the agency of cutter means, to define a second end of the band; securing the second end of the band to the first end through the agency of sealing means. 
     The stated object is realized similarly according to the invention in a machine for securing at least one band of strip material around a substantially parallelepiped block of sheets, in particular banknotes, comprising first feed means by which at least one continuous strip decoiling from a roll is caused to advance along a first predetermined path; a channel serving to guide the block of sheets and establishing a second predetermined path transverse to the first path; gripping means positioned externally of the channel and in such a way as to interact with a leading portion of the continuous strip and restrain one end of the selfsame strip; second feed means by which a block of sheets is made to advance along the channel and enter into contact with the strip; bending means operating in conjunction with the gripping means, by which the leading portion of the strip is flattened against a face of the block positioned rearwardmost relative to a direction followed along the second path; diverter means located on the side of the channel opposite to the bending means, by which the strip is engaged and drawn into overlapping contact with at least a part of the leading portion; cutter means by which the strip is severed at the overlap to define a second end of the band; sealing means by which the second end of the band is secured to the first end. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will now be described in detail, by way of example, with the aid of the accompanying drawings, in which: 
     FIGS. 1,  4  and  9  illustrate a machine embodied according to the present invention for strapping or banding groups of banknotes, viewed schematically in a side elevation and seen in a succession of operating steps; 
     FIGS. 2 to  8  illustrate a portion of the machine as in FIGS. 1,  4  and  9 , viewed schematically in a side elevation and seen in a succession of operating steps; 
     FIGS. 10 and 11 show a detail of the machine as in FIGS. 1,  4  and  9 , viewed respectively in plan from above and in elevation from the front, with certain parts omitted for clarity, and illustrating a succession of operating steps; 
     FIG. 12 illustrates a block of bundled banknotes banded by a machine as illustrated in FIGS. 1 to  11 , viewed in perspective. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to the accompanying drawings and to FIG. 4 in particular,  1  denotes a portion of a machine, in its entirety, by which bands  2  of a strip material  3  are secured around blocks  4  of sheets, one block  4  consisting in an ordered stack either of single banknotes  5 , or alternatively of banknotes  5  sorted previously into a plurality of bundles  6 , as in the example illustrated. 
     The machine  1  comprises a frame  7  supporting a vertical bulkhead  8 . The vertical bulkhead  8  in turn supports a temporary storage area  9  indicated fragmentarily and schematically in the drawings, being of familiar embodiment, where the bundles  6  are allowed to gather, also a station  10  at which the block  4  is formed, a banding station  11  at which the strip  3  is secured around the block  4 , and an outfeed station  12  from which the finished block  4  emerges with at least one band  2 . 
     The temporary storage area  9  holding bundles  6  of banknotes  5  is placed in the topmost part of the machine  1  from where the bundles  6  are fed toward the forming station  10  by way of an infeed duct  13 , extending along a feed path denoted P, of which the end nearest the forming station  10  is equipped with a shutter  14  capable of movement between a position in which the duct  13  is closed, as in FIGS. 1,  2 ,  4  and  9 , and a position in which the duct  13  is open as indicated in FIG.  3 . 
     The station  10  at which the blocks  4  are formed incorporates a barrier  15  positioned to halt the bundles  6  and marking the end of the duct  13 , also a pair of support elements  16  located one on either side of the duct relative to the plane of FIG. 1, each embodied as an arm  17  appearing substantially L-shaped in section and offering a flat contact surface  17   a  to each bundle  6  as it reaches the end of the infeed duct  13 . 
     The arms  17  are rotatable about respective axes A between a first position in which a bundle  6  is restrained, and a second open position in which the surfaces  17   a  are distanced from the bundle  6  held hitherto. 
     The aforementioned shutter  14  connects the end part of the infeed duct  13  conveying the bundles  6  with a vertical channel  18  of which the function is to guide the movement of the block  4  accumulating in the forming station  10 . 
     The strip  3 , a continuous material made to decoil conventionally from a roll (not illustrated), is directed through the agency of first feed means  19  along a first substantially rectilinear path Q that intersects the channel  18  transversely at the level of the banding station  11 . The block  4  of bundles  6  is caused in turn to advance along the channel  18  following a second feed path R extending parallel to the selfsame channel. 
     The channel  18 , considered positionally relative to a direction F 1  followed by the strip  3  along the first path Q, comprises a rear vertical wall  18   a  and a front vertical wall  18   b.    
     Considered in relation to a direction F 2  followed along the second path R, the block  4  of bundles  6  presents a rear face  4   a  and a front face  4   b , also two mutually parallel side faces  4   c  and  4   d  disposed perpendicular to the first path Q. 
     The first feed means  19  comprise a first slide  20  located in the vicinity of the banding station  11  and capable of movement along the first rectilinear path Q on a relative track  21  between a retracted first position shown in FIGS. 1,  2 ,  4 ,  8  and  9 , remote from the channel  18 , and an extended second position shown in FIGS. 2,  5 ,  6  and  7 , in which its forwardmost end  20   a  occupies the channel  18 . 
     The slide  20  comprises a rack  22  engaged in mesh with a pinion  23  mounted to a shaft  23   a  that is carried by the bulkhead  8  and set in rotation by a motor of conventional type (not illustrated) in such a way as to reciprocate the slide  20  between the first and second positions. 
     The first feed means  19  further comprise a pair of pinch rolls  24  and  25  mounted to the slide  20  and rotatable about respective axes  24   a  and  25   a . The two rolls  24  and  25 , of which at least one  25  is power driven by means of conventional embodiment (not illustrated), are disposed tangentially one to the other between the roll and the station  11 , one in contact with either side of the strip  3 , in such a way as to draw the strip  3  along the first feed path Q. 
     The slide  20  comprises an upright bracket  26  at the end remote from the forwardmost end  20   a , also an arm  27  anchored pivotably to an intermediate part of the bracket and capable of angular movement in relation to the bracket about an axis denoted B, induced by an actuator  28  anchored similarly to the free top end of the bracket  26 . The free end  27   a  of the arm  27  directed toward the channel  18  carries a heat seal bit  29 . The actuator  28  serves to rotate the arm  27  between a raised at-rest position (see FIGS.  5  and  6 ), and a lowered operating position (see FIG. 7) in which the bit  29  is brought into contact with the strip  3  to effect a seal. 
     Also associated with the first slide  20 , at the aforementioned forwardmost end  20   a , is a diverter element  30  embodied in such a way as to displace the strip  3  when the slide  20  is caused to move forward from the retracted first position. 
     The slide  20  further comprises a clamp element  31  mounted translatably to the underside and connected dynamically by way of a spring  32 , through which the movement of the slide  20  is transmitted to the selfsame element  31 . 
     The end of the clamp element  31  directed toward the channel  18  presents a surface  31   a  positioned to enter into contact with the block  4  and thus pin the strip  3  against the corresponding side face  4   c , also a lip  31   b  positioned to engage the corner edge of the block  4  along which the rear face  4   a  meets the side face  4   c.    
     The banding station  11  also comprises a gripper device  33  positioned on the side of the second feed path R opposite from the first feed means  19 , of which the function is to interact with a leading portion  34  of the strip  3  and restrain the relative leading end  3   a.    
     Referring in particular to FIGS. 2,  3 ,  5  and  8 , the gripper device  33  comprises a first jaw  35  and a second jaw  36  mounted coaxially to a shaft  37  supported by the bulkhead  8  and centered on an axis of rotation denoted C, each affording a respective flat surface  35   a  and  36   a  by which the strip  3  is engaged. The jaws  35  and  36  rotate as one with the shaft  37 , which is coupled to and driven by a motor of conventional embodiment indicated schematically as a block  38 , and can also be rotated one relative to another through the agency of an actuator  39  of which the body  39   a  is rigidly associated with the second jaw  36  and the rod connected in such a way as to rotate the first jaw  35  about the shaft  37  toward and away from the second jaw  36 . 
     The first jaw  35  of the gripper device  33  carries a knife  40  positioned so as to locate in a slot  30   a  afforded by the diverter element  30 , which extends substantially parallel to the axis C of rotation and is shaped to admit the knife  40 , causing the strip  3  to be cut as illustrated in FIG.  6 . 
     The machine also comprises second feed means  41  operating in the channel  18 , including a companion element  42  by which the block  4  of sheets is caused to advance along the second path R. 
     The companion element  42  comprises cantilevered members  43 , each of which affording a platform  43   a  offered in direct contact to the front face  4   b  of the block  4 . 
     Each of the members  43  is rigidly associated with a second slide  44  capable of movement on a track (not shown) extending vertically along the rear wall  18   a  of the channel  18 . 
     The second slide  44  is set in motion along the second path R by transmission means  45  consisting in a belt looped around a live wheel  46  positioned at the bottom end of the channel  18 , driven by a relative motor  45   a , and a loose wheel  47  positioned at the top end of the channel  18 ; the two wheels  46  and  47  are mounted to respective shafts  46   a  and  47   a  carried by the bulkhead  8 . 
     The block  4  of bundled banknotes  5  is compacted by a device  48  located near the banding station  11 ; the device  48  in question functions substantially as a gripper, comprising a pair of first reaction arms  49  placed on either side of the second path R (one only is visible in the drawings), and a second arm provided by the companion element  42 . 
     Each of the two first reaction arms  49  presents a substantially L-shaped outline and comprises a flat surface  49   a  offered in direct contact to the rear face  4   a  of the block  4 , pivotable about an axis D is lying parallel to the first path Q between a first operating position of contact with the block  4  and a second at-rest position distanced from the second feed path R, in which the block  4  of banknotes  5  is able to advance along the path R. 
       50  denotes a push rod  50  located in the vicinity of the outfeed station  12  where the block  4  emerges from the channel  18 , which is caused by a relative actuator  51  to reciprocate between a first at-rest position, distanced from the channel  18 , and a second operating position assumed when the block  4  is pushed out of the channel  18 . 
     As discernible from FIG.  10  and FIG. 11, the shaft  37  to which the jaws  35  and  36  of the gripper device  33  are mounted is capable also of axial motion brought about by an actuator  52  between a first position, in which the device  33  engages the strip  3  (shown by phantom lines in FIG.  10 ), and a second position in which the device  33  releases the strip  3  (solid lines in FIG.  10 ). 
     The actuator  52  is connected to the shaft  37  by way of a bellcrank  53  mounted to a fixed pivot  54  and coupled articulatedly with the shaft  37  and the actuator  52  respectively by two further pivots  53   a  and  53   b.    
     In operation, with reference to the foregoing and to the illustrations of the accompanying drawings, groups or bundles  6  of banknotes  5  gathering in the temporary storage area  9  are fed by gravity down the infeed duct  13  toward the forming station  10  at predetermined intervals, along the relative path P. The passage of the bundle  6  along the duct will be halted by the obstacle offered to one side face  6   d  by the barrier  15 . 
     The shutter  14  is incorporated into the final stretch of the duct  13  along which the bundles  6  proceed, to the end that in the closed position of FIG. 1 the bundle  6  can be effectively prevented by the shutter  14  from leaving the duct  13  and at the same time supported by the selfsame shutter up to the moment of locating against the barrier  15 . 
     In like manner to the block  4 , and with reference to the direction F 2  followed by the block  4  along the second feed path R, the bundle  6  presents a rear face  6   a  and a front face  6   b , mutually opposed. The shutter  14  opens subsequently and allows the bundle  6  to drop freely onto the flat surfaces  17   a  of the support elements  16 , which will be occupying the aforementioned first position with the selfsame surfaces  17   a  lying substantially in a common plane. 
     The arms  17  are able to rotate about their axes A and thus to assume the open position in which the flat surfaces  17   a  no longer disallow the passage of the bundle  6 , which thus becomes free to advance down the channel  18  and along the feed path R. 
     Once free of the support elements  16  as indicated in FIG. 2, the bundle  6  is able to drop under its own weight onto the companion element  42 , settling on the two platforms  43   a  afforded by the respective members  43 . 
     The companion element  42  is now set in motion down the channel  18  which, it will be remembered, stands substantially vertical and determines the second feed path R followed by the block  4 . The channel  18  is compassed by the aforementioned rear and front vertical walls  18   a  and  18   b , disposed respectively upstream and downstream in the feed direction F 1  of the first rectilinear path Q, as well as by side panels (not illustrated) located on opposite sides of the bundles  6 , parallel to the viewing plane of FIG.  2 . The barrier  15  consists effectively in an extension of the front vertical wall  18   b , located beyond the longitudinal compass of the channel  18 . 
     The movement of the companion element  42  takes in a first receiving step, identifiable as a plurality of receiving positions assumed by the element  42  in the upper part of the channel  18  (FIGS. 2 and 3) during which the bundles  6  released from the infeed duct  13  are deposited one on top of another on the members  43  to form an ordered stack that becomes a block  4 , also a second operating position assumed in the central part of the channel  18 , in which the strip  3  is secured around the block  4  (FIG.  4 ), and a third outfeed position assumed at the bottom of the channel  18  (FIG.  9 ), in which the block  4  is ejected from the channel  18  by the push rod  50 . 
     In the course of the receiving step, as indicated in FIGS. 2 and 3, the companion element  42  moves intermittently in the direction denoted F 2  along the second feed path R in such a way as to advance, each time a new bundle  6  of banknotes  5  is added to the forming stack, through a distance substantially equal to the thickness of the single bundle  6 . 
     In this way the rear face  6   a  of the last bundle  6  added to the stack will always be positioned at the same optimum distance from the shutter  14 . It is in fact important that the distance in question should not be too great, since an excessively long fall of the bundle  6  when released from the duct  13  could jeopardize the correct alignment of the bundle  6  with others of the block already stacked beneath. 
     For this very reason, the support elements  16  are proportioned in such a manner as to accommodate no more than one or two bundles  6  received from the infeed duct  13 . If the arms  17  of the elements  16  were made longer, they would be able to accommodate a greater number of bundles  6  while waiting for the companion element  16  to complete the handling of the previous block  4 , and this undeniably would be advantageous in speeding up the banding cycle; unfortunately, the distance covered by the first bundle  6  in this instance when dropping onto the flat surfaces  17   a  of the support element  16  would be too great, and liable to jeopardize its correct alignment with the following bundles  6 . 
     Observing FIG. 2 it will be seen that while the companion element  42  is in the receiving position, the step of advancing the strip  3  along the first rectilinear path Q also takes place. The peripheral surfaces of the contrarotating pinch rolls  24  and  25  possess a high coefficient of friction, and the high angular velocity of the rolls will ensure that the leading portion  34  of the strip  3  is propelled forward along the first feed path Q in the relative direction F 1  at a velocity sufficient to ensure its timely arrival at the gripper device  33 , located externally of the channel  18  in alignment with the banding station  11 . 
     The strip  3  is also guided along the first path by the first slide  20 , of which the functions include accompanying the strip  3  in its movement toward the gripper device  33  by traveling likewise along the first path Q. The movement in question is brought about by rotation of the pinion  23  engaged in meshing contact with the rack  22  afforded by the slide  20 . 
     The pinch rolls  24  and  25  cease rotating as soon as the leading portion  34  of the strip  3  reaches the gripper device  33 . 
     At the moment the strip  3  is directed forward, the flat surface  35   a  of the first jaw  35  will be positioned substantially tangential to the first path Q as indicated by phantom lines in FIG. 2; as the pinch rolls  24  and  25  cease rotation, the leading portion  34  of the strip  3  will be disposed facing the flat surface  35   a  and lying outside the dimensional compass of the channel  18 . From this position, identifiable as the open position of the jaws, the first jaw  35  is caused by the actuator  39  to rotate counterclockwise as viewed in FIG. 2, relative to the second jaw  36 . The body  39   a  of the actuator  39  is rigidly associated with the second jaw  36 , whereas the rod  39   b  is connected to the first jaw  35  and thus brings about its rotation. During this same rotation, the flat surface  35   a  of the jaw  35  interferes with the strip  3 , displacing it and pushing it against the flat surface  36   a  of the second jaw  36 . The position in which the flat surfaces  35   a  and  36   a  are brought ultimately into mutual contact with the strip  3  interposed between them is identifiable as the closed position of the jaws  35  and  36 , in which the strip  3  is restrained by the gripper device  33 . 
     The surfaces  35   a  and  36   a  will either be fitted with rubber inserts, or exhibit surfaces machined in such a way as to ensure a high coefficient of friction and thus maximize the grip on the strip  3 . 
     Once the strip  3  is held by the gripper device  33  the first slide  20  will begin retracting, as the rack  22  is driven by the pinion  23  now rotating in the direction opposite to the direction mentioned previously, and moves in the direction opposite to that of the arrow F 1  so as to regain its original position outside the dimensional compass of the channel  18  occupied by the bundles  6  (FIG.  3 ). 
     The strip  3  is thus placed across the channel  18 , tensioned between the roll on the one hand and the jaws  35  and  36  of the gripper device  33 , which restrains the leading portion  34 , on the other. 
     With the strip  3  in this configuration and the bundles  6  continuing to accumulate on the companion element  42  after dropping from the infeed duct  13 , the companion element  42  itself in advancing along the second path R will ultimately impinge on the strip  3  as illustrated in FIG.  3 . 
     Once the bundles  6  accumulating on the companion element  42  have collected in the requisite number for the formation of a block  4 , the shutter  14  closes so that no more bundles  6  can drop from the duct  13  and the companion element  42  assumes the second operating position, with the rear face  4   a  of the block  4  aligned substantially in the same plane as the first feed path Q (see FIG.  4 ). 
     Another function of the first feed means  19  is to ensure that the continuous strip  3  will continue to decoil from the roll when diverted by the block  4  and assume a profile substantially of “U” outline, hugging three faces of the block  4 , namely the front face  4   b  and the two mutually parallel side faces  4   c  and  4   d . More exactly, the side faces  4   c  and  4   d  lie respectively upstream and downstream in the direction F 1  followed by the strip  3  along the first feed path Q. 
     With the block  4  occupying this position and the companion element  42  at a standstill, the first reaction arms  49  of the compacting device  48  assume their aforementioned first operating position of contact with the block  4 , each rotating about the relative axis D from the at-rest position outside the dimensional compass of the channel  18 , to a position in which the respective flat surface  49   a  lies parallel to the first feed path Q and breasted with the rear face  4   a  of the block  4 . 
     The operating position thus described is shown in FIG. 4, where it will be seen that the first arms  49  oppose and prevent any movement of the block  4  of bundles  6  toward the top end of the channel  18 , i.e. in the direction opposite to the direction F 2  followed along the second path R. 
     The companion element  42  ceases movement in the normal feed direction F 2 , whereupon the direction of rotation of the motor  45   a  is reversed and the members  43 , functioning as the second arm of the compacting device  48 , begin applying a compressive force to the block  4  which in turn is prevented from moving upward by the flat surfaces  49   a  of the reaction arms  49 . 
     The block  4  of bundles  6  is thus compacted by the compressive force, which will be varied according to whether the banknotes  5  being processed are new or soiled; more exactly, soiled banknotes tend to exhibit more irregularities precisely by reason of their prolonged use, so that the distance covered by the companion element  42  when compacting soiled banknotes, indicated schematically by phantom lines in FIG. 4, will be greater than when compacting new notes. 
     When the block  4  has been compressed to a certain degree, the compacting device  48  will remain in place to maintain the compacted condition. 
     The machine further comprises a bending device  55  located in the vicinity of the banding station  11 , by which the leading portion  34  of the strip  3  is flattened against the rear face  4   a  of the block  4 . The device  55  in question is provided by the two jaws  35  and  36  of the gripper device  33 , which are caused to rotate together as one about the common axis C once the leading portion  34  of the strip  3  has been gripped firmly between them. 
     When performing the function of bending device  55  therefore, the two jaws  35  and  36  are rotated as one by the motor  38  about the relative axis C in such a manner that the leading portion  34  of the strip  3  is bent over and flattened against the rear face  4   a  of the block  4 , as illustrated in FIG.  5 . 
     In this situation the thin plate constituting the flat surface  36   a  of the second jaw  36  is interposed between the strip  3  and the rear face  4   a  of the block  4 . The strip  3  is thus pinned against the second jaw  36  by the gripping action of the first jaw  35 , of which the flat surface  35   a  overlaps the flat surface  36   a  of the second jaw  36  only in part. The non-overlapping area left by the jaws  35  and  36  is positioned to accommodate a sealable overlapping portion  56  of the strip  3  coinciding with the ends of the band  2 , as will shortly be described. 
     The function of the clamp element  31 , positioned immediately beyond the diverter element  30  in the direction F 2  followed along the second feed path R and capable also of movement parallel to the first feed path Q, is to pin the strip  3  against the side face  4   c  of the block  4  of banknotes  5 . To this end, the clamp element  31  is mounted translatably to the first slide  20 , connected dynamically by way of a spring  32  such as will transmit the movement of the slide  20  to the element  31  and extend deformably as the element  31  locates against the side face  4   c  and the slide  20  continues its movement along the first path Q. 
     As the slide advances in the direction F 1  of the first feed path Q, in effect, the clamp element  31  is urged against the block  4  in such a way that the contact surface  31 a restrains the strip  3  breasted with the side face  4   c , and the lip  31   b  engages the corner edge along which the side face  4   c  meets the rear face  4   a.    
     As intimated above and shown clearly in FIG. 5, the first slide  20  continues to advance along the first feed path Q after the clamp element  31  has come to a stop against the block  4 . In the course of this same movement, the strip  3  is engaged by the diverter element  30  associated with the end  20   a  of the slide  20  nearer the channel  18  and, wrapping around the element  30 , caused to form a loop  57  of which a first branch  57   a  is breasted with the rear face  4   a  of the block  4 , partly overlapping the leading portion  34  of the selfsame strip  3 , and a second branch  57   b  extending substantially parallel with the first remains connected to the roll. 
     As mentioned previously, the slot  30   a  afforded by the diverter element  30  is disposed substantially parallel to the axis C of rotation of the gripper element  33  and shaped so as to accommodate part of the knife  40  associated with the first jaw  35 . 
     As discernible from FIG. 6, the forward motion of the first slide  20  terminates when the knife  40  enters the slot  30   a , striking against one edge and making a scissor cut through the strip  3  at the point where the loop  57  is formed. 
     The effect of cutting the continuous strip  3  is to separate a discrete length  58  that provides the band  2 . 
     It will be seen from FIG. 6 that the rotation of the pinch rolls  24  and  25  is now inverted, as indicated by the arrows, thereby drawing the second branch  57   b  of the loop  57  away from the channel  18  through a distance such that when the arm  27  is lowered into the operating position, the heat seal bit  29  can enter into contact with the overlapping portion  56  of the discrete portion  58  and effect a join (see FIG.  7 ). The second branch  57   b  of the loop thus becomes the leading portion  34  of the strip  3  offered to the next block  4  of bundles  6 , while the first branch  57   a  constitutes the trailing end  59  of the band  2  currently in place. 
     To reiterate, a portion of the trailing end  59  is placed over a portion of the leading portion  34  of the strip  3  to establish the overlapping portion  56  of the discrete length  58 . 
     During the sealing step, as shown in FIG. 7, the flat surface  36   a  of the second jaw  36  remains squarely in contact with the rear face  4   a  of the block  4 , providing a reaction element onto which the heat seal bit  29  can descend, and an insulating element by which the block  4  is protected from the heat generated through the bit  29 . 
     The arm  27  remains permanently associated with the first slide  20  throughout all its movements along the first path Q, including the step of directing the strip  3  toward the gripper device  33 , but will be lowered by the actuator  28  into the operating position only when the leading portion  34  of the strip  3  has been overlapped by the trailing end  59  of the discrete length  58  following the cut. 
     As discernible readily in FIG. 8, the slide  20  is retracted to a position remote from channel  10  once the strip  3  has been sealed, and with the knife  40  now free of the slot  30   a , the first jaw  35  could be rotated clockwise so to return the flat surface  35   a  to the former position substantially tangential to the first feed path Q. 
     The second jaw  36  on the other hand is prevented from rotating as the relative flat surface  36   a  remains trapped between the sealed band  2  and the rear face  4   a  of the block  4 . Accordingly, the grip between the jaws  35  and  36  is slackened initially by causing the one to rotate relative to the other through the agency of the actuator  39 , whereupon the flat surface  36   a  is made to translate axially in the manner now to be described. 
     Observing FIG. 11, the shaft  37  supporting the jaws  35  and  36  is capable of axial motion produced by the actuator  52  and the bellcrank  53  which, to reiterate, is anchored to a fulcrum pivot  54  and coupled articulatedly to the shaft  37  on the one hand and the actuator  52  on the other. 
     The linear movement of the actuator  52  causes the bellcrank  53  to rotate about the fulcrum pivot  54  and thus translate the shaft  37 . The two jaws  35  and  36  translate as one with the shaft  37  until the flat surface  36   a  of the second jaw  36  has cleared the band  2  completely, as indicated by the solid lines in FIG. 10, leaving the block  4  of notes free to proceed further along the second path R. 
     The shaft  37  is now rotated by the motor  38  in such a manner as to return the gripper device  33  to an angular position outside the dimensional compass of the channel  18 , indicated by the phantom lines of FIG.  11 . Thereafter, the shaft is translated in the opposite direction and the gripper device  33  thus repositioned axially in readiness to receive the strip  3 , as illustrated by the solid lines in FIG.  11 . 
     With reference to FIG. 9, the first reaction arms  49  are distanced from the operating position of contact with the block  4 , rotating about the respective axes D to resume the at-rest position externally of the channel  18 . 
     The block  4  of bundled banknotes  5  secured by the band  2  of strip material  3  is now free to advance with the companion element  42  as it continues along the second path R toward a discharge position at the outfeed station  12 , where the push rod  50  is caused to extend by the corresponding actuator  51  and eject the block  4  from the channel  18 . 
     The companion element  42  is then able to reascend (FIG. 1) toward the upper part of the channel  18  in readiness to receive more bundles  6  and begin forming another block  4 . 
     Importantly, it will be seen that the machine in the embodiment disclosed can be used to apply more than one band  2  to each block  4 , performing the same set of operations described and illustrated simply utilizing two strapping or banding units in parallel, as illustrated in FIG. 10. A unit in this context will include the full set of parts needed in accordance with the present invention to apply one band, namely the first feed means  19  for positioning the strip  3 , the gripper device  33 , the bending device  55 , the knife  40  and the heat seal bit  29 . 
     FIG. 12 illustrates a block  4  of bundles  6  secured by two parallel bands  2 . 
     As alternatives to the solution described in the foregoing specification, the machine according to the present invention might be configured with the rectilinear second feed path R, and therefore the channel  18 , positioned horizontally or obliquely; such arrangements might be adopted in order to meet space saving requirements dictated by the design of the currency processing system in which the machine disclosed is utilized.