Patent Publication Number: US-6220591-B1

Title: Apparatus for processing flexible, sheet-like products

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an apparatus for processing flexible, sheet-like products and which is intended for slowing down the products fed to a receiving region of the apparatus and then conveying the products to a transfer region. 
     An apparatus of this general type is known from EP-B-0 638 503. The apparatus disclosed therein has a decelerating drum which is driven in rotation about its axis and on which there are arranged, at regular intervals one behind the other in the circumferential direction, conveying elements which are formed in each case by a pair of rollers. A feed conveyor introduces a signature sheet tangentially, in relation to the decelerating drum, into the roller gap of the pair of rollers respectively moving through a receiving region. In this case, the speed of circulation of the pair of rollers about the drum axis and the circumferential speed of the rollers oriented in the direction of circulation in the roller gaps are brought into line with the conveying speed of the feed conveyor. The leading edge of the signature sheet is then driven by a desired distance into the roller gap before the rotation of the pairs of rollers about the axes thereof is stopped. In a transfer region, the rollers are then driven in a direction of rotation counter to the direction of rotation in the receiving region, in order to release the relevant signature sheet from the roller gap. This results in the signature sheets being additionally slowed down and makes it possible for the signature-sheet speed to be adapted to the speed of a removal conveyor which receives the signature sheets. The reversing drive of the pairs of rollers, on the one hand, requires considerably outlay and, on the other hand, results in the products being subjected to considerable stressing, which limits the processing capacity of the apparatus. 
     It is thus an object of the present invention to provide an apparatus of the described type wherein, in the case of a high processing speed, careful handling of the products is ensured. 
     SUMMARY OF THE INVENTION 
     The above and other objects and advantages of the present invention are achieved by the provision of an apparatus which has a plurality of conveying elements arranged in a circular array one behind the other on a support member. The support member is rotated about a central axis, so that the conveying elements each move along a circulatory path from a receiving region to a transfer region. Each conveying element includes a continuously driven roller segment and a mating element. The periphery of the roller segment includes at least one circumferentially running surface section and at least one recess section. This configuration, in association with the mating element, forms, during movement through the receiving region, an introduction gap which, for the introduction of a product, has a large width which then decreases continuously and thus stabilizes the product. The leading, closed end of the introduction gap moves in the introduction direction as a result of the rotation of the roller segment, and this contributes to the products being carefully decelerated when they reach the end of the introduction gap. The approximately simultaneous formation of a conveying gap prevents the products from springing back, which contributes to reliable functioning of the apparatus along with a high processing capacity. The continuous driving of the roller segments results in the products being conveyed through the conveying elements, which are formed in each case by the roller segment and the mating element, in order to be discharged in the transfer region. There is thus no need for the products to be slowed down to a standstill, and then accelerated again in relation to the conveying elements. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is explained in more detail with reference to several exemplary embodiments illustrated in the accompanying drawings, in which, purely schematically: 
     FIG. 1 is a view, partially in section, of a first embodiment of the apparatus, having conveying elements which, during circulation, maintain a mutually parallel position; 
     FIG. 2 shows, in the same illustration as FIG. 1, a second embodiment, in the case of which, during circulation, the conveying elements maintain an unaltered position in relation to the circulatory path; and 
     FIG. 3 shows, in the same illustration as FIGS. 1 and 2, a third embodiment of the apparatus, with directing elements which are assigned to the conveying elements and which are arranged in the manner of a paddle wheel. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. 
     The apparatus illustrated in FIG. 1 has a conveying arrangement  10  which is designed in the manner of a drum, is driven continuously in the direction of the arrow U and has conveying elements  12  arranged in a cage-like manner. Said conveying elements are intended for receiving, during movement through a receiving region  14 , in each case one flexible, sheet-like product  19  from a feed conveyor  18 , which in the example shown is designed as a belt conveyor  16 , for slowing down said product, conveying it further and transferring it, in a transfer region  20 , to a removal conveyor  22 , which is arranged downstream of the conveying arrangement  10 . 
     Each conveying element  12  has a roller segment  24 , which is driven such that it rotates continuously in a direction of rotation D—which is counter to the direction of circulation U—about its roller axis  24 ′, and a mating element  26 , which interacts with said roller segment. In the example shown, the mating element  26  is designed as an endless belt  28  which is guided around two deflecting rollers  30 . The belt  28  is of elastomeric design and, by way of its active strand, which is directed toward the roller segment  24 , interacts, between the deflecting rollers  30 , with said roller segment. 
     The deflecting rollers are mounted in a freely rotatable manner at both ends on triangular carrier plates  32  which, for their part, are mounted in a freely rotatable manner on the shaft  34  of the roller segment  24 . The carrier plates  32  are driven, for example, via a planet gear mechanism such that, during circulation along the circulatory path  35  formed by the circle  36 , the conveying elements  12 , which are formed by the belt  28  and roller segment  24 , maintain a mutually parallel position or, in other words, the straight lines through the axes of the deflection rollers  30  assigned to a conveying element  12  remain parallel to other another. The shafts  34 , which are coaxial with the roller axes  24 ′, are distributed uniformly along a circle around a common axis of circulation  38  and are mounted in a freely rotatable manner on disc-like bearing plates  40  which, for their part, are seated in a rotationally fixed manner on a hollow shaft  42 , which is coaxial with the axis of circulation  38 . While one bearing plate  40  is assigned the drive means which are intended for keeping the conveying elements  12  parallel and are designed, for example, as planet gear mechanisms, the other bearing plate  40  is assigned the drive means which are intended for driving the roller segments  24  continuously in the direction of rotation D and are likewise designed, for example, as planet gear mechanisms. For this purpose, the hollow shaft  42  may have a rotationally fixed shaft engaging through it, the center wheels of the planet gear mechanisms being wedged onto said rotationally fixed shaft. During rotation of the bearing plates  40 , the planet wheels, which are mounted on said bearing plates, mesh with the stationary center wheels and, for their part, act on the carrier plates  32  and/or shafts  34 , are driven. It is also possible for the belts  28  to be driven, counter to the direction of rotation D, at the same time as the roller segments  24 . As far as a possible embodiment of the drive for the roller segments  24  and mating elements  26  is concerned, and also for the purpose of keeping the conveying elements  12  parallel, reference is expressly made to CH Patent Application No. 1998 1283/98, which is incorporated herein by reference. 
     Each of the roller segments  24  shown in FIG. 1 has three recess sections  44  and, between in each case two recess sections  44 , a circumferentially running lateral-surface section  46 , which is coaxial with the roller-segment axis  24 ′. Each recess section  44 , which is of concave design, is thus followed by a lateral-surface section  46 . The cross section of the roller segment  24  is similar to a three-point star, of which the blunt points end on a circle. 
     The rotary position of the conveying elements  12  is selected such that, in the receiving region  14 , the conveying elements  12  are arranged at least more or less in the radial direction in relation to the axis of circulation  38 . Furthermore, the roller segments  24  are synchronized in relation to the bearing plates  40  such that, when a conveying element  12  moves into the receiving region  14  in the direction of circulation U, in each case one lateral-surface section  46  butts against the belt  28 , and forces the latter back. The recess section  44  which follows the lateral-surface section  46  thus forms, together with the active strand of the belt  28 , a wide, narrowing introduction gap  48  in which the feed conveyor  18  can introduce, without obstruction, a product  19  with the edge  52  leading, as seen in the feed direction Z. The rotation of the roller segment  24  means that, in the receiving region  14 , the introduction gap  48 , which is closed downstream, as seen in the direction of rotation D, becomes longer and longer and, at the same time, becomes narrower in the radially outward direction in relation to the roller axis  24 ′. The feed conveyor  18  and the conveying arrangement  10  are synchronized such that in each case the transition from the recess section  44  which bounds the introduction gap  48  into the following lateral-surface section  46  closes the introduction gap  48 , with the product  19  which has been introduced into the introduction gap  48  being clamped firmly between it and the belt  28 , in a region which is remote from the leading edge  52  at least more or less at that point in time at which the product  19  comes into abutment, by way of the leading edge  52 , against the leading end region of the recess section  44 , said end region acting as a stop  62 , i.e. against the closed end of the introduction gap  48 , and the lateral-surface section  46  forms, together with the belt  28 , a conveying gap  54  for the gripped product  19 . 
     Each roller segment  24  is assigned a guide element  56 , which crosses the belt  28  downstream of the conveying gap  54  in order for the product conveyed through the conveying gap  54  to be deflected, around the roller segment  24 , in the radially outward direction in relation to the axis of circulation  38 . 
     In the example according to FIG. 1, the removal conveyor  22  is designed as a clamp-type transporter  58 , of which the successive transporting clamps  60  are moved, synchronously with the conveying elements  12 , through the transfer region  20  in the removal direction W—which in this case is oriented in the same direction as the direction of circulation U. In this case, the transporting clamps  60  are directed toward the conveying arrangement  10  in order that the radially outwardly deflected products  19  can be conveyed by the conveying elements  12  into the transporting clamps  60  with the edge  52  in front. The transporting clamps  60  are closed approximately at the same time as the conveying gap  54  is eliminated, in that the last lateral-surface section  46 , which bounds a conveying gap  54  for the relevant product  19 , runs off the belt  28 . 
     In the example shown, during one revolution of the bearing plates  40  in the direction of circulation U about the axis of circulation  38 , the roller segments  24  rotate twice about their roller axes  24 ′ in the opposite direction of rotation D, and thus three times in relation to the bearing plates  40 . 
     In the case of that embodiment of the apparatus which is shown in FIG. 2, the conveying arrangement  10  is likewise designed in a cage-like manner. Arranged on the bearing plates  40 , which are arranged on the hollow shaft  42 , are six bearing shafts  64 , which are parallel to the axis of circulation  38 , distributed uniformly along a coaxial circle. Deflecting rollers  30  are mounted in a freely rotatable manner on the bearing shafts  64 . In each case two mutually associated deflecting rollers  30  of adjacent bearing shafts  64  have a continuous elastomeric belt  28 ′ gripping around them. A plurality of tapes  28 ′ arranged one beside the other correspond to the belt  28  of the embodiment shown in FIG.  1 . The roller segments  24  are distributed uniformly on the circle  36  around the axis of circulation  38 . They are seated on the shafts  34 , which, as seen in the direction of circulation U, are mounted on the bearing plates  40 , centrally between in each case two bearing shafts  64  and radially outside the tapes  28 ′. The roller segments  24 , in turn, are driven continuously in the direction of rotation D, which is counter to the direction of circulation U, for example by means of a planet gear mechanism. 
     Each roller segment  24  has a recess section  44 , which is of concave design. The distance between the tape  28 ′ and the shafts  34  is selected such that, with the recess section  44  directed toward the relevant tape  28 , the roller segment  24  butts, by way of the two transitions from the recess section  44  to the lateral-surface section  46 , against the tape  28 ′—if there is no product  19  there—and, if appropriate, forces said tape back. In any case, the tape is forced back when it interacts with the lateral-surface section  46 . 
     Each roller segment  24  is assigned a guide element  56  which runs through between adjacent tapes  28 ′ and engages around the relevant roller segment  24  at a distance therefrom. Downstream of the associated roller segment  24 , as seen in the direction of circulation U of the conveying arrangement  10 , the guide element  56  runs coaxially with the roller axis  24 ′ and ends approximately 30° in front of a radial line through the roller axis from the axis of circulation  38 . Upstream of the roller segment  24 , the guide element  56  runs approximately in a straight line and forms a tangent to the downstream, radially outwardly directed section of the guide element  56  assigned to the following roller segment  24 . 
     The feed conveyor  18 , which is likewise designed as a belt conveyor  16 , is aligned at least more or less with the upstream, straight-line section of the guide element  56  when the latter is moved past the end of the feed conveyor  18  in the receiving region  14 . 
     The roller segments  24  are driven such that, during movement past the feed conveyor  18  in the direction of the arrow U, they butt against the tape  28 ′ by way of the lateral-surface section  46 . As soon as they have been moved past the feed conveyor  18 , the latter introduces in each case one product  19 , with the edge  52  in front, between the relevant roller segment  24  and the trailing section of the associated guide element  56 . As a result of the rotation of the roller segment  24 , the leading end of the recess section  44  has reached the tape  28 ′ and forms, together with the latter, the introduction gap  48 , into which the product  19  can be introduced, with play, with the edge  52  in front. The leading end region of the recess section  44 , in turn, forms the stop  62  for the leading edge  52 . At least more or less at the same time as the leading edge  52  comes into contact with the stop  62 , the trailing end of the recess section  44 , as seen in the direction of rotation D, and the start of the lateral-surface section  46  run onto that flat side of the product  19  which is located opposite the tape  28 ′ and clamp said product firmly, and the lateral-surface section  46  forms, with the tape  28 ′, the conveying gap  54 . 
     The removal conveyor  22 , which is designed as a belt conveyor  65 , is arranged beneath the conveying arrangement  10 . The removal direction W is counter to the direction of circulation U in the transfer region  20 . The products  19  conveyed through the conveying gap  54  with the edge  52  in front are deflected by means of the guide elements  56  and then deposited, in the transfer region  20 , on the removal conveyor  22 , an imbricated formation S being formed in the process. The speed of circulation of the roller segments  24 , and thus of the conveying elements  12 , about the axis of circulation  38 , the circumferential speed of the roller segments  24  and the speed of the removal conveyor  22  are coordinated with one another such that, during release from the conveyor gap  54 , the speed of the leading edge  52  in the removal direction W corresponds at least more or less to the conveying speed of the removal conveyor  22 . This makes it possible to form a precise imbricated formation. 
     The conveying elements  12 , which are formed by the roller segments  24  and associated tapes  28 ′, maintain their position in relation to their circulatory path  35 . 
     In the case of that embodiment of the apparatus which is shown in FIG. 3, the conveying arrangement  10  is designed in the manner of a paddle wheel  66 . Paddle wheels  66  are used, for example, in rotary printing machines for delivering the folded products  19 . In the same way as in the case of the embodiment shown in FIG. 2, the roller segments  24  are mounted on the bearing plates  40  and, during rotation of the bearing plates about the common axis of circulation  38  in the direction of circulation U, are driven continuously in the opposite direction D. The mating element  26  for each roller element  24 , in turn, is formed by tapes  28 ′ which are guided around deflection rollers  30 . The deflection rollers  30  which follow the roller segment  24 , as seen in the direction of circulation U, are arranged further outward in the radial direction, in relation to the axis of circulation  38 , than the leading deflection rollers  30 . The mating element  26 , which maintains its position in relation to the circulatory path, is thus arranged in an inclined manner in relation to the circulatory path. 
     Each roller segment  24 , in turn, is assigned a guide element  56  which crosses the tape  28 ′ downstream of the conveying gap  54 , as seen in the direction of rotation D of the roller segments  24 , and runs in the radially outward direction in order for the products  19  conveyed through the conveying gap  54  to be deflected, around the roller segment  24 , in the radially outward direction. The guide element  56  ends at the trailing deflection rollers  30 , as seen in the direction of circulation U, of the respectively preceding conveying element  12 . Mounted on the bearing shaft  64  of said deflecting rollers  30 , furthermore, is a directing-element section  68  which can be changed over from a guide-element position  70 , in which it forms an extension of the guide element  56  in order for the product  19  conveyed in the conveying gap  54  to be deflected in the radially rearward direction, into a directing-element position  72 . In the directing-element position  72 , the directing-element section  68  forms a tangent, by way of its free end, to the periphery of the following roller segment  24 . For this purpose, the roller segment  24  is formed by axially spaced-apart roller-segment elements, between which the tines of the rake-like directing-element section  68  can engage. 
     In the directing-element position  72 , the directing-element section  68  is aligned with a directing element  74 , which is assigned to each roller segment  24 . Said directing element is arranged firmly on the bearing plates  40  and starting from its leading end, which is located at the roller segment  24 , runs rearwardly counter to the direction of circulation U, with the distance from the axis of circulation  38  increasing, to the following roller segment  24 , from which it is spaced apart in the radial direction. 
     Respectively adjacent directing elements  74  form, with the appropriate directing-element section  68  and the mating element  26 , a pocket  78  which, as seen in the direction of circulation U, is open to the recess and is closed at the front by means of the appropriate roller segment  24 . 
     The feed conveyor  18 , which in turn is designed as a belt conveyor  16 , is arranged above the conveying arrangement  10 , and its conveying direction Z is aligned with the pocket  78  moved past it in each case. The feed conveyor  18  is intended for introducing a product  19  with the edge  52  in front into each pocket  78  moved past it. 
     A lever projects from each directing-element section  68 , and a rolling element  80  is mounted in a freely rotatable manner at the free end of said lever. Said rolling element is guided in a stationary, groove-like guide  82  which runs around the axis of circulation  38 . By means of this guide control, the directing-element section  68  is changed over between the guide-element position  70  and the directing-element position  72 . In the receiving region  14 , the directing-element section  68  is located in the directing-element position  72  and together with the directing element  76 , which is located on the outside in the radial direction, bounds an introduction gap for the product  19 . In the receiving region  14 , the concave recess section  44  of the roller segment  24  forms, with the associated tapes  28 ′, the narrowing introduction gap  48 , the directing element  76  being intended for directing the leading edge  52  into the recess section  44 . The leading end region of the recess section  44 , as seen in the direction of rotation D, in turn forms the stop  62  for the leading edge  52  of the product  19 . The rotation of the roller segment  24  in the direction D is, in turn, synchronized such that the trailing end of the recess section  44 , and thus the leading end of the lateral-surface section  46 , come into abutment against the flat side of the product  19  and clamp the latter firmly with the mating element  26 , approximately at the same time as the leading edge  52  comes into abutment against the stop  62 . As a result of the continuous further rotation of the roller segment  24 , the product  19  is then conveyed through the conveying gap  54  with the edge  52  in front and by means of the guide element  56  and the directing-element section  68  assigned thereto, which in the meantime has been changed over into the guide-element position  70 , is deflected, around the roller segment  24 , in the radially outward direction and in the rearward direction in relation to the direction of circulation U. 
     The removal conveyor  22 , which is designed as a belt conveyor  65 , in turn runs beneath the conveying arrangement  10 , and its removal direction W is oriented in the same direction as the direction of circulation U in the transfer region  20 . In the transfer region  20 , the products  19  are conveyed out of the conveying gap  54  and deposited on the removal conveyor  22 , an imbricated formation S being formed in the process. The inertia of the products  19  causes the latter, following release from the conveying gap  54 , to slide out of the gap formed by the roller segment  24 , guide element  56  and directing-element section  68 ; the speed of circulation of the conveying elements  12 , the axis of circulation  38  and the circumferential speed of the roller segments  24  as well as the conveying speed of the removal conveyor  22  are coordinated with one another such that in the transfer region, as seen in the removal direction W, the products  19  which are to be transferred from the conveying arrangement  10  to the removal conveyor  22  are approximately at a standstill in relation to the active strand of said conveyor. It is also conceivable to arrange in the transfer region  20  additional known guides or conveying elements, such as chains or rollers, for conveying the products  19  precisely out of the gap. 
     Once they have left the transfer region  20 , the directing-element sections  68  are changed over from the guide-element position  70  into the directing-element position  72 . 
     In the case of all the embodiments shown, the products  19  are fed to the receiving region  14  at a distance one behind the other by means of the feed conveyor  18 . The feed conveyor  18  may be, for example, part of a folding or cutting arrangement of a rotary printing machine. 
     It is possible, in the case of the embodiment shown in FIG. 1, for the clamp-type transporter  58  to be replaced by a different transporting arrangement, for example a belt conveyor. It is also conceivable, in the case of the embodiments shown in FIGS. 2 and 3, for the removal conveyor  22  to be designed as a clamp-type transporter  58 . 
     Depending on the removal direction W of the removal conveyor  22 , it is possible to form, in the transfer region  20 , an imbricated formation S in which the leading edge  52  in the conveying arrangement  10  is trailing or leading in relation to the removal direction W. 
     Common to all the embodiments is the fact that the products  19  are introduced in a closed introduction gap  48 , decelerated there and conveyed through the conveying element  12 . It is thus not necessary at any time for them to be slowed down to a standstill in relation to the conveying arrangement  10 , which ensures careful handling along with a high processing capacity. Furthermore, the products  19  are not subjected to any abrupt changes in direction. 
     The mating elements  26  may be designed differently; they may thus have rollers arranged, for example, in a resilient manner.