Abstract:
The present invention is generally directed to providing a method and apparatus for accurately and efficiently folding a flat product (e.g., a web of paper or signatures obtained therefrom) during its delivery. Exemplary embodiments provide a single device for performing the two functions of folding and decelerating flat products. Rotatable seizing elements of a deceleration drum interface with any known folding cylinder having a known tucker blade assembly. As such, the accurate and mark-free folding of a conventional jaw folder can be achieved with any desirable paging, including the wide maximum paging range typically associated with rotary tucker blade folders. A deceleration drum according to the present invention can interface with any folding cylinder having a tucker blade assembly used to create a cross-fold, and can thereby replace any conventional combination of a folder (e.g., rotary tucker blade folder or jaw folder) and associated downstream deceleration device. Seizing devices associated with the deceleration drum create a fold off of a fixed (e.g., a non-retractable) or a retractable tucker blade of the folding cylinder, each seizing element acting as a jaw which removes the signature, and creates the fold during product deceleration and delivery.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a method and apparatus for the delivery of flat products, and more particularly, to a method and apparatus for the delivery of flat products which are to be folded during delivery in a printing press. 
     2. State of the Art 
     Conventional printing presses include devices for delivering flat printed products from one stage of the press to another. For example, a web of flat material which has been sliced along its length into multiple ribbons, is typically transported to a location where the ribbons are subsequently cut along their width into signatures. The signatures are then folded one or more times to form the multiple pages of, for example, a magazine or newspaper. A typical newspaper folder may receive a collection of ribbons which have already been previously folded one or more times, and be required to implement an additional fold, such as a half fold. The number of pages which the newspaper folder is required to fold can vary widely up to, on the order of 100 broadsheet pages or more. The devices used to implement these folds include jaw folders and rotary tucker blade folders. 
     Jaw folders, such as jaw folders which use a jaw to interface with a fixed tucker blade, have the advantage of providing a relatively accurate, mark-free cross-fold, such as an accurate half fold. However, jaw folders are constrained in the number of pages which they can fold due to limited engagement of tucker blades and jaws used to implement the folds, as well as by the space between the tucker blade and jaw cylinders. For example, typical jaw folders are limited to folding 64 pages or less. 
     Rotary tucker blade folders which use a rotating cylinder having either fixed or retractable tucker blades, can accommodate a large range of paging when implementing a fold. However, rotary tucker blade folders are less accurate than jaw folders, and create more marking on the printed product. 
     Thus, the newspaper folders used in conventional printing presses have resulted in the accurate folding of only a limited number of pages, or have resulted in folding a larger number of pages with less accuracy. Accordingly, it would be desirable to provide a newspaper folder which can provide the accuracy and absence of marking associated with a jaw folder, without being subject to the maximum paging range typically associated with a jaw folder. Further, it would be desirable to achieve such advantages in a relatively simple configuration which can provide positive and accurate delivery of a folded product, using for example, a gripping transport device. 
     Although gripping transport devices are available, these devices have not been suitable for transporting folded product of, for example, a printing press used in printing newspaper. For example, U.S. Pat. No. 4,132,403, U.S. Pat. No. 4,290,595, U.S. Pat. No. 4,629,175, U.S. Pat. No. 4,767,112, U.S. Pat. No. 4,629,175, U.S. Pat. No. 5,452,886 and U.S. Pat. No. 5,560,599 disclose the use of gripping elements associated with a rotatable gripper drum for grasping a product and transporting the product to a second location. Further, these patents disclose that during transport, the product can be decelerated from a first speed to a second speed. In addition, in co-pending U.S. application Ser. No. 08/707,518, entitled “Method and Apparatus For Conveying Flat Printed Products”, a conveying device for flat printed products is disclosed which includes plural arms, each having a seizing device for seizing signatures emerging from a transport device. 
     However, the foregoing documents do not address the inability of conventional folders to provide accurate, mark-free folding of a wide maximum paging range, or the transport of folded products from such a folder to a downstream location of a printing press. 
     SUMMARY OF THE INVENTION 
     The present invention is generally directed to providing a method and apparatus for accurately and efficiently folding a flat product (e.g., a web of paper or signatures obtained therefrom) during its delivery. Exemplary embodiments provide a single device for performing the two functions of folding and decelerating flat products. Rotatable seizing elements of a deceleration drum interface with any known folding cylinder having a known tucker blade assembly. As such, the accurate and mark-free folding of a conventional jaw folder can be achieved with any desirable paging, including the wide maximum paging range typically associated with rotary tucker blade folders. A deceleration drum according to the present invention can interface with any folding cylinder having a tucker blade assembly used to create a cross-fold, and can thereby replace any conventional combination of a folder (e.g., rotary tucker blade folder or jaw folder) and associated downstream deceleration device. Seizing devices associated with the deceleration drum create a fold off of a fixed (e.g., a non-retractable) or a retractable tucker blade of the folding cylinder, each seizing element acting as a jaw which removes the signature, and creates the fold during product deceleration and delivery. 
     Generally speaking, exemplary embodiments of the present invention relate to an apparatus and associated method for conveying flat products, where the apparatus comprises: a folding cylinder for use in folding a flat product; and at least one arm mounted at a first end for rotation about an axis, and having a seizing device located at a second end for establishing a fold in said flat product while seizing said flat product from said folding cylinder. 
     Exemplary embodiments are also directed to an apparatus and associated method for conveying flat products, wherein the apparatus comprises: a transport device for rotational transport of a flat product; and at least one arm mounted at a first end for rotation about an axis, and having a seizing device located at a second end, said seizing device being oriented relative to said transport device for seizing said flat product from said transport device in a radial direction with respect to said rotational transport of said flat product. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other features of the present invention will become apparent to those skilled in the art upon reading the following description of preferred embodiments of the invention in conjunction with the accompanying drawings, wherein like elements have been designated by like reference numerals, and wherein: 
     FIG. 1 shows an exemplary interface between a cutting cylinder, a folding cylinder and a deceleration drum configured in accordance with an exemplary embodiment of the present invention; 
     FIG. 2 illustrates details of an interface between the exemplary FIG. 1 folding cylinder and deceleration drum; and 
     FIG. 3 shows an interface between the deceleration drum of FIG. 1 and a downstream conveyor for further transport of a flat product from the deceleration drum. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows a portion of a printing press which includes an apparatus for conveying flat products, such as the web, ribbon or signatures, processed in a rotary printing press. The FIG. 1 apparatus is illustrated as a folder portion  100  of a rotary printing press. The folder portion  100  shows how a web or ribbon used to create a printed medium, such as a magazine or newspaper, can be cut off between a cutting cylinder  102  and a folding cylinder  104 . 
     In the FIG. 1 embodiment, the lead edge of, for example, a web  106  is established by interaction of the cutting cylinder and the folding cylinder. More particularly, the cutting cylinder  102  can be considered to include two knives  108  which rotate in a counterclockwise direction with the cutting cylinder  102 . The folding cylinder  104  can be configured in any known fashion. In the FIG. 1 embodiment, the folding cylinder includes two anvils  110  which rotate in a clockwise direction with the folding cylinder  104 . Movement of the cutting cylinder and the folding cylinder is synchronized in known fashion, such that a portion of the web  106  enters a nip between the cutting cylinder and the folding cylinder, where it is severed by a knife  108  which presses through the web and into a corresponding anvil  110 . As a leading edge of the web  106  is established, it is impaled by pins in known fashion, using one of two cam actuated pin assemblies  112  which operate in known fashion to fix the lead edge to a surface of the folding cylinder  104 . 
     The folding cylinder  104  can be considered a transport device for transporting a flat product, such as the web  106  or any portion thereof, from the nip between the cutting cylinder and the folding cylinder to a deceleration drum  114 . The general operation of a deceleration drum is, for example, described in co-pending U.S. application Ser. No. 08/707,518, entitled “Method and Apparatus For Conveying Flat Printed Products”, the disclosure of which is hereby incorporated by reference in its entirety. 
     The folding cylinder  104  can be configured to include any known tucker blade assembly to create a cross-fold. For example, the folding cylinder can include at least one fixed (e.g., extended, non-retractable) or retractable tucker blade, such as tucker blade  120 . In the FIG. 1 embodiment, two tucker blades  120  are illustrated in conjunction with an optional, stationary cam  116  for retracting and extending the tucker blades during operation. Rollers  118  which rotate with the folding cylinder  104  move along an outer periphery of the cam  116 . The rollers  118  interface with tucker blades  120 . Because the FIG. 1 folder portion  100  is configured to accommodate transport of a single signature which has been severed from the web  106  to the deceleration drum  114 , the folding cylinder  104  includes two pin assemblies. Thus, a succeeding lead edge severed from the web  106  can be pinned while an immediately preceding signature is removed from the folding cylinder by the deceleration drum. 
     Where the two tucker blades are retractable, the folding cylinder  104  can include two opposing rollers  118 . To illustrate the manner by which each roller  118  and an associated tucker blade  120  interact with the deceleration drum, six successive positions of a roller  118  and associated tucker blade  120  have been illustrated in the lower half of the folding cylinder  104 . As can be seen therein, when the roller  118  rotates with the folding cylinder  104  along a periphery of the cam  116 , the roller  118  and associated tucker blade  120  are moved radially away from the rotational axis of the folding cylinder  104 , in a direction toward a nip between the folding cylinder  104  and the deceleration drum  114 . This movement of the tucker blade pushes the signature  122  radially outward from the folding cylinder so that it can be positively seized by a seizing device of the deceleration drum  114 . 
     As shown in FIG. 1, the signature  122 , after having been severed by the knife  108 , is transported 180° by the folding cylinder. At this position, the cam operated tucking blade  120  drives a portion (typically the center) of the signature radially outward from the folding cylinder&#39;s surface, where it can be seized by a seizing element of the deceleration drum  114 . 
     The deceleration drum  114  includes at least one arm  124  mounted at a first end for rotation with the deceleration drum about an axis  134 . The arm itself is also rotatably mounted about an axis  126 . The arm  124  has a seizing device  128  located at a second end for establishing a fold in the signature  122  while seizing the signature  122  from the folding cylinder  104 . In accordance with the present invention, the seizing device  128  includes a gripper having a movably mounted gripper finger  130  and a fixedly mounted gripper bar  132 , which interact with a radially outward extending tucker blade  120  of the folding cylinder  104  to grasp the signature  122  at a location at which the signature is to be folded. 
     In contrast to conventional gripper elements, the arm  124  and associated seizing device  128  of the exemplary FIG. 1 embodiment are configured such that the seizing device  128  is radially oriented in a first position relative to the folding cylinder  104  and thus, to a surface of the signature  122  which faces the seizing device. This first position is maintained over at least a predetermined range of rotation of the arm about an axis of rotation  134  of the deceleration drum. In the FIG. 1 embodiment, the seizing device is oriented such that the gripper bar  132  is aligned with respect to a radial axis of the folding cylinder; that is, an axis normal (i.e., perpendicular) to a surface of the folding cylinder  104  and to the surface of the signature  122 . This radial orientation is maintained over an arc of rotation of the deceleration drum which is sufficient for the seizing device to properly orient itself relative to signature  122 , to then seize the signature  122  at the location at which it is to be folded, and to then radially withdraw the signature from the folding cylinder  104 . In the FIG. 1 embodiment, this arc is shown to be about 45°, but as those skilled in the art will appreciate, can be any angle deemed sufficient in aligning the seizing device and performing the seizing operation given the rotational velocities of the deceleration drum and the folding cylinder. 
     The deceleration drum  114  as shown in FIG. 1 includes four arms  124 . Although not specifically illustrated, each of the four arms would, of course, include an associated seizing device  128 . Each of the arms  124  is mounted at its rotational axis  126  with a pin  136  to an eccentric  140  that moves about the deceleration drum&#39;s axis  134 . 
     The eccentric mounting will cause the arm  124  to have a velocity which varies during its rotation about the axis  134  of the deceleration drum  114 . More particularly, the arms  124  will be at their maximum rotational velocity when oriented at the position where a signature  122  is grasped. The arms will then decelerate as they rotate in a counterclockwise direction from this location (i.e., as they rotate from the position at the top of the deceleration drum as oriented in FIG. 1 to a position at the bottom of the deceleration drum as oriented in FIG.  1 ). At their point of lowest velocity (i.e., when oriented at the bottom of FIG.  1 ), a grasped signature is transferred to a gripper of a downstream conveyor. A gripper-to-gripper exchange is conducted between the deceleration drum  114  and conveyor grippers  144  of the downstream conveyor  146 . Thus, exemplary embodiments provide a positive control over a signature in its transfer from the folding cylinder  104  to the downstream conveyor  146 . 
     Each of the arms  124  includes a linkage  139  which has a roller that moves along a periphery of a stationary cam  138 . In addition, a linkage  142  is used to achieve interaction between the linkage  139  and the eccentric  140 . The stationary cam  138  is used in conjunction with linkage  139 , to either close or open the movably mounted gripper finger  130  of each seizing device. For this reason, the recess of the cam  138  transitions at the point at which the seizing device  128  is to grasp a signature, and then transitions again at a point at which the seizing device is to release the signature to the downstream conveyor. As shown in FIG. 1, the recessed portion of cam  138  extends over a range of about 120°, or more or less. 
     To ensure that the seizing devices are oriented with a radial axis of the folding cylinder  104  over a predetermined range of rotation of the deceleration drum, each seizing device can be articulated about an axis independently of the arm  124 . Articulation of each seizing device is also controlled in response to the combined lateral and radial movement of the linkage  139  as it rotates with the deceleration drum. To illustrate this, three positions of a given seizing device  128  are illustrated at, and about, a position of the arm  124  at which the signature  122  is seized. These three illustrated positions are shown in greater detail in FIG.  2 . 
     Referring to FIG. 2, the seizing device  128  is illustrated as being articulated about an axis  202 . Again, articulation about the axis  202 , in accordance with exemplary embodiments of the present invention, is configured such that the fixedly mounted gripper bar  132  maintains a radially aligned position with respect to a normal to a surface of the folding cylinder  104  and a surface of the signature to be folded. In accordance with exemplary embodiments, maintenance of this orientation is achieved using the linkage  139  to control rotation of the seizing device  128  about the axis  202 . As shown in FIG. 2, the linkage  139  also interacts with the cam  138  to control an opening and closing of the movably mounted gripper finger  130  via additional linkages  204 ,  206  and  208 . 
     As further illustrated in FIG. 2, a stop point of the movably mounted gripper finger  138  is controlled via a spring bias stop  210 . The spring bias stop  210  includes a spring  212  which biases a spring rod  214  against a movable roller  216  mounted to the linkage  208 . This feature permits the seizing device  128  to accommodate a wide maximum paging range without readjusting the folder portion  100 . In addition, the movably mounted gripper finger  138  can itself, be spring biased to further enhance the flexibility of the seizing device in accommodating a wider maximum paging range. 
     Once a signature has been seized by a seizing device of the deceleration drum, the arm  124  rotates in a counterclockwise direction about the axis  134  to decelerate the signature. In accordance with exemplary embodiments, the arm and associated seizing device decelerate to a velocity which is approximately 20% of the peak velocity at the time a signature is grasped. However, those skilled in the art will appreciate that any desired variations in velocity of the deceleration drum can be implemented in accordance with a specific press operation. Increased deceleration of the arm  124  is illustrated by an increase in the angle between the arm  124  and the linkage  142 . For example, note that an angle between these elements is relatively wide (e.g., on the order of 145°) when the linkage  142  is at a position designated “ 8 ” with respect to the outer circle of numbers  1 - 24  in FIG. 1 (the inner circle of numbers constituting positions  1 - 24  of the arms  124 ). To the contrary, the angle between the arm  124  and the linkage  142  is much smaller during an acceleration mode (such as that where the linkage  142  is at position “ 20 ” in FIG.  1 ). 
     After the arm  124  has rotated to a position at which it is to release a signature, the movably mounted gripper finger  130  is opened. In the FIG. 1 illustration and as more clearly shown in FIG. 3, a seizing device  128  can be seen to move into a position adjacent a conveyor gripper  144 . At this location, the movably mounted gripper finger  130  is opened via interaction of the linkage  139  and the cam  138 . A corresponding cam device, which does not constitute a part of this invention and which is therefore not illustrated, can be used to concurrently cause the conveyor gripper  144  to close on the signature, and thereby positively transport it to a downstream location of the printing press. 
     Although exemplary embodiments of the present invention have been described in the context of the elements shown in the Figures, numerous variations will be apparent to those skilled in the art. For example, rather than using a folding cylinder with a retractable tucker blade, a cylinder configured with a fixed tucker blade can be used to interface with the seizing elements of the deceleration drum. 
     In addition, rather than implementing a half fold as was illustrated with respect to FIG. 1, any type of fold can be implemented in accordance with exemplary embodiments of the present invention including, but not limited to double parallel folds. Further, although exemplary embodiments have been described in conjunction with transfer of a flat product of a folding cylinder, those skilled in the art will appreciate that a deceleration drum configured in accordance with the present invention can be used in conjunction with any cylindrical transfer device of a printing press. Further, exemplary embodiments can be used in conjunction with the transport of individual signatures, or webs. 
     Those skilled in the art will appreciate that the FIG. 1 embodiment is shown in cross section. As such, each of the arms  124  and associated seizing devices appear in cross section. Those skilled in the art will appreciate that each such arm and associated seizing device can be configured as a plurality of aligned arms and seizing devices which extend across a width of a given signature to be grasped from the folding cylinder  104 . Alternately, the arms and/or seizing devices can be configured as a single arm and/or seizing device having a width which corresponds to a width of a given signature, or any desired width. In addition, those skilled in the art will appreciate that to provide gripper-to-gripper transfer during a handoff of a signature from the deceleration drum  114  to the downstream conveyor  146 , some provision for interleaving the seizing devices  128  and the conveyor grippers  144  can be provided to ensure that positive control is maintained over a signature during the entire handoff operation. For example, the seizing devices  128  can be interleaved with the conveyor grippers  144  across the width of a signature. 
     In accordance with exemplary embodiments, a relatively compact, positive control transfer device can be achieved. Exemplary embodiments can provide the accuracy of a conventional jaw folder, yet provide enhanced flexibility in paging capability, and provide relatively mark-free transfer of flat products. In the exemplary embodiments illustrated herein, a single device can be used to both fold a flat product and to provide controlled slowdown of the flat product, with a controlled transfer to a downstream gripper conveyor. A gripper-to-gripper transfer eliminates the space typically associated with a pickup station required for the downstream conveyor, and minimizes misses between a belt conveyor of a conventional folder and the pickup station. 
     It will be appreciated by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential character thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the appended claims rather than the foregoing description and all changes which come within the meaning and range of equivalents thereof are intended to be embraced therein.