Abstract:
A feeder device for printed products is provided including at least one first drum rotatable about a first axis; at least one second drum rotatable about a second axis; and an actuator coupled to the at least one first drum and the at least one second drum for reciprocating the at least one first drum and the at least one second drum axially. A printed product conveying device and a method of transporting printed products are also provided.

Description:
The present invention relates generally to feeder devices and more particular to feeder devices used in finishing equipment in the graphics industry to feed printed products to a moving conveyor. 
     BACKGROUND 
     In finishing equipment in the graphics industry, sheet feeder devices may drop signatures perpendicularly to a conveying apparatus, such as a chain conveyor, moving below the feeder device. Signatures leaving the feeder grippers may only be moving downwards and are not translated tangentially with respect to the conveying apparatus (i.e., in the horizontal direction). So, just before the signatures contact the conveying apparatus the signatures may have a tangentially velocity of zero. When each signature contacts the conveying apparatus, due to the velocity difference the signature may slide a very small distance, then begin traveling at the same tangential velocity as the surface of the conveying apparatus. Conveying apparatuses may have lugs to positively register and align the signatures. The immediate tangential acceleration of the signatures by the conveying apparatus may cause the lugs or the surface of the conveying apparatus to mark or damage the signatures. As a result, the velocity of the conveying apparatuses may sometimes be limited to minimize the tangential velocity difference between the signatures and the conveying apparatus. 
       FIG. 1  schematically shows a perspective view of a conventional signature transporting device  110 . Signature conveying device  110  includes a feeder device  112  and a collecting apparatus  114 . Feeder device  112  includes a pair of transfer drums  116 ,  118  rotatable in one direction about a first axis  120  and a pair of opposing transfer drums  126 ,  128  rotatable in the opposite direction about a second axis  130 . Drums  116 ,  118  may have grippers that grip an open edge of a folded signature and drums  126 ,  128  may have grippers that grip the other open edge of the folded signature. Drums  116 ,  118 ,  126 ,  128  may receive the open edges of each signature first and transport the signature downward while moving the open edges away from one another to open the signature. The signature is then released downwardly by the drums  116 ,  118 ,  126 ,  128  to collecting apparatus  114 , which may be a chain or a saddle conveyor. 
     Axes  120 ,  130  are aligned horizontally with respect to a direction Y and drums  116 ,  118 ,  126 ,  128  transport signatures vertically downward in a direction Z. Collecting apparatus  114  receives signatures traveling vertically downward in direction Z and transports the signatures horizontally in direction Y. Axes  120 ,  130  are rotatably fixed in position, such that drums  116 ,  118 ,  126 ,  128  are not translatable in a direction X, direction Y or direction Z. Therefore, drums  116 ,  118 ,  126 ,  128  only convey signatures in direction Z and just before signatures contact collecting apparatus  114 , signatures have no velocity in direction Y. 
     SUMMARY OF THE INVENTION 
     A feeder device for printed products is provided including at least one first drum rotatable about a first axis; at least one second drum rotatable about a second axis; and an actuator coupled to the at least one first drum and the at least one second drum for reciprocating the at least one first drum and the at least one second drum axially. 
     A printed product conveying device is also provided including a device for transporting printed products in a first direction; a conveyor downstream from the device traveling in a direction perpendicular to the first direction for receiving the printed products from the device; and an actuator coupled to the device for translating the device in the second direction. 
     A method of transporting printed products including the steps of receiving a printed product and transporting the printed product in a first direction with at least one first drum rotating about a first axis and at least one second drum rotating about a second axis; translating the at least one first drum and the at least one second drum in a second direction that corresponds to a direction of the first axis and a direction of the second axis to accelerate the printed product in the second direction; and releasing the printed product from the at least one first drum and the at least one second drum to a conveyor traveling in the second direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is described below by reference to the following drawings, in which: 
         FIG. 1  schematically shows a portion of a conventional signature transporting device; 
         FIG. 2  schematically shows a signature transporting device in accordance with an embodiment of the present invention; 
         FIG. 3  schematically shows a perspective view of a dual direction conveying apparatus and a saddle conveyor of the signature transporting device shown in  FIG. 2 ; and 
         FIG. 4  schematically shows a perspective view of a dual direction conveying apparatus according to an embodiment of the present invention; and 
         FIG. 5  shows shows a graph of a displacement and velocity of drums shown in  FIGS. 2 to 4  versus positions of cams shown in  FIGS. 2 to 4  for a cam profile according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 2  schematically shows a side view of a signature transporting device  10  according to an embodiment of the present invention. Signature transporting device  10  includes a feeder  11 , which includes pick-up drum  13  and a dual direction conveying apparatus  50 , and a conveyor, which in this embodiment is a saddle conveyor  14 . Pick-up drum  13  may include a suction device and grippers  52  and may pull folded signatures  15  from a signature stack. Dual direction conveying apparatus  50  may include first transfer drums  16 ,  18 , second transfer drums  26 ,  28  and an actuator  100 . In an alternative embodiments, first transfer drums  16 ,  18  may be replaced by a single transfer drum or more than two transfer drums and second transfer drums  26 ,  28  may be replaced by a single transfer drum or more than two transfer drums. Pick-up drum  13  may rotate in a first direction (e.g., clockwise) to grip a folded edge  15   a  of each signature  15  and pass each signature  15  to first transfer drums  16 ,  18  by open edges  15   b ,  15   c . First transfer drums  16 ,  18  may include at least one gripper  54  to receive signatures  15  from pick-up drum  14 . First transfer drums  16 ,  18  may be fixedly coupled to a shaft  21  rotatable in a second direction (e.g., counterclockwise) about an axis  20  to grip one or both of open edges  15   b ,  15   c  and transport each signature  15  towards second transfer drums  26 ,  28 . Second transfer drums  26 ,  28 , which may include at least one gripper  56 , may be fixedly coupled to a shaft  31  rotatable in the first direction (e.g., clockwise) about an axis  30 . Second transfer drums grip open edge  15   c  as first transfer drums  16 ,  18  grip open edge  15   b  and via rotation, transfer drums  16 ,  18 ,  26 ,  28  open each signature  15 . Open signatures  15  are released downward to saddle conveyor  14  so that open edges  15   b ,  15   c  straddle saddle conveyor  14 . Saddle conveyor  14  is traveling perpendicular to signature  15  (e.g., out of the page) in direction Y ( FIG. 3 ) and may include lugs  25 . 
     After pick-up drum  13  releases each signature  15  to first transfer drums  16 ,  18 , actuator  100 , which is coupled to shafts  21 ,  31 , may translate transfer drums  16 ,  18 ,  26 ,  28  in the direction of travel of saddle conveyor  14  (e.g., out of the page). In a preferred embodiment, after signature  15  is released to first transfer drums  16 ,  18  by pick-up drum  13 , actuator  100  may accelerate drums  16 ,  18 ,  26 ,  28  from a zero velocity in direction Y ( FIG. 3 ). Actuator  100  may accelerate drums  16 ,  18 ,  26 ,  28  up to a velocity of an outer surface of saddle conveyor  14  for the release of signature  15  to saddle conveyor  14 . As a result, each signature  15  may travel at the same velocity as the outer surface of saddle conveyor  14  as each signature  15  contacts the outer surface of saddle conveyor  14 . After one signature  15  is released by drums  16 ,  18 ,  26 ,  28 , actuator  100  translates drums  16 ,  18 ,  26 ,  28  back into the initial position for receiving another signature  15  from pick-up drum  13 . 
       FIG. 3  schematically shows a perspective view of dual direction conveying apparatus  50  and saddle conveyor  14  shown in  FIG. 2 . Transfer drums  16 ,  18  are rotatable in the second direction (e.g., counterclockwise) about axis  20  and transfer drums  26 ,  28  are rotatable in the first direction (e.g., clockwise) about axis  30 . Drums  16 ,  18 ,  26 ,  28  may receive signatures  15  ( FIG. 2 ), and transport each signature  15  ( FIG. 2 ) downward to saddle conveyor  14  in an open arrangement. 
     Axes  20 ,  30  are aligned horizontally with respect to direction Y and drums  16 ,  18 ,  26 ,  28  transport successive signatures  15  ( FIG. 2 ) vertically downward in direction Z. Saddle conveyor  14  receives each signature  15  ( FIG. 2 ) traveling vertically downward in direction Z and transports each signature  15  ( FIG. 2 ) horizontally in direction Y. Shafts  21 ,  31  are configured such that drums  16 ,  18 ,  26 ,  28  are translatable in direction Y. Therefore, dual direction conveying apparatus  50  may convey signatures in direction Y and direction Z. 
     Shafts  21 ,  31  are translatable in direction Y by actuator  100 , which may include two cylindrical cams  32 ,  34  having respective grooves  36 ,  38  for cam followers  40 ,  42 . Grooves  26 ,  28  may extend between the ends of the respective cams  32 ,  34  so that cams  32 ,  34  may be axially displaced during rotation. Cam followers  40 ,  42 , which may be coupled together via a connector  41 , are fixed in position, for example via a connection to a side support frame. As cams  32 ,  34  rotate about respective axes  20 ,  30  cam followers  40 ,  42 , via interaction with grooves  36 ,  38  cause cams  32 ,  34 , shafts  21 ,  31 , and drums  16 ,  18 ,  26 ,  28  to reciprocate in direction Y. Ends of shafts  21 ,  31  may rotate in bearings that are configured to allow shafts  21 ,  31  to be axially reciprocated by the interactions between cam followers  40 ,  42  and cams  32 ,  34 . In order to accelerate signatures  15  ( FIG. 2 ), cams  32 ,  34  are phased such that portions of grooves  36 ,  38  that are closest to drums  16 ,  18 ,  26 ,  28  interact with cam followers  40 ,  42  as drums  16 ,  18  receive signatures  15  and portions of grooves  36 ,  38  that are furthest from drums  16 ,  18 ,  26 ,  28  interact with cam followers  40 ,  42  as drums  16 ,  18  release signatures. Grooves  36 ,  38  (i.e., profiles of cams  32 ,  34 ) may be varied in design to dictate the velocity in direction Y that signatures  15  ( FIG. 2 ) are released from drums  16 ,  18 ,  26 ,  28  to saddle conveyor  14  and the duration that drums  16 ,  18 ,  26 ,  28  are in each position through the axial reciprocation (i.e., signature receiving position and signature releasing position). 
     In an alternative embodiment, a single cam follower may be positioned between cams  32 ,  34  for interacting with both grooves  36 ,  38  to reciprocate shafts  21 ,  31  as cams  32 ,  34 , shafts  21 ,  31 , and drums  16 ,  18 ,  26 ,  28  are rotated. 
     In order to convert dual direction conveying apparatus  50  into conventional form, such that drums  16 ,  18 ,  26 ,  28  are not reciprocated in direction Y during rotation, cam followers  40 ,  42  may simply be disengaged from cams  32 ,  34 . 
       FIG. 4  schematically shows a perspective view of a dual direction conveying apparatus  70  according to another embodiment of the present invention. Dual direction conveying apparatus  70  is configured in substantially the same manner as dual direction conveying apparatus  50  shown in  FIGS. 2 and 3 , except that shafts  21 ,  31  are each coupled to respective resilient elements, which in this embodiment are return springs  72 ,  74  that provide a force on cams  32 ,  34  and cam followers  40 ,  42 , acting to center drums  16 ,  18 ,  26 ,  28  and maintaining positive contact between cam followers  40 ,  42  and respective cams  32 ,  34 . 
       FIG. 5  shows a graph of a displacement and velocity of drums  16 ,  18 ,  26 ,  28  by cams  32 ,  34  and cam followers  40 ,  42  of actuator  100  shown in  FIGS. 2 to 4  versus positions of cams  32 ,  34  for a cam profile according to an embodiment of the present invention. For this cam profile, a quarter revolution of cams  32 ,  34  is used to accelerate drums  16 ,  18 ,  26 ,  28  and a signature gripped by drums  16 ,  18 ,  26 ,  28  to a velocity of conveyer  14 , at which time drums  16 ,  18 ,  26 ,  28  release the signature, which is illustrated in  FIG. 5  as release point  200 . A next quarter revolution of cams  32 ,  34  is used to decelerate shafts  21 ,  31  and drums  16 ,  18 ,  26 ,  28  to a zero velocity. A third quarter revolution is used to accelerate shafts  21 ,  31  and drums  16 ,  18 ,  26 ,  28  in the opposite direction and a fourth quarter revolution is used to decelerate shafts  21 ,  31  and drums  16 ,  18 ,  26 ,  28  so drums  16 ,  18 ,  26 ,  28  can receive and transport a subsequent signature. 
     In other embodiments, different cams with different profiles may be used. For example, cams may be provided that only accelerate drums to a percentage of the velocity of saddle conveyor  14 , to minimize, but not completely eliminate the tangential velocity difference between saddle conveyor  14  and signatures. 
     The following equations may be used to match 100% of the tangential velocity of saddle conveyor  14  using a cycloidal cam profile.
 
 y=L/π[θ− ½sin(2θ)]  (equation 1);
 
 y′=L/π[θ− cos(2θ)]  (equation 2);
 
 y″= 2 L /π[sin(2θ)]  (equation 3);
 
 y′″= 4 L/π [cos(2θ)]  (equation 4);
 
 y′=dy/dθ   (equation 5);
 
 y*=dy/dt=dy/dθ*dθ/dt=y′ω   (equation 6);
 
     where: 
     L=cam rise; 
     θ=cam angle; 
     ω=cam angular velocity; 
     y=cam displacement; 
     y*=cam velocity (tangential velocity); 
     y′=rate of change of y with respect to θ; 
     y″=rate of change of y′ with respect to θ; and 
     y′″=rate of change of y″ with respect to θ. 
     In the preceding specification, the invention has been described with reference to specific exemplary embodiments and examples thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative manner rather than a restrictive sense.