Abstract:
An apparatus for opening and depositing a signature onto a transporting device includes a continuously rotating gripper cylinder having a first shaft and carrying at least one signature. First and second opening cylinders are arranged below the gripper cylinder to open the signature carried by the rotating gripper cylinder and deposit the opened signature with the opened side facing downward onto the transporting device. The first and second opening cylinders each have a second and third shafts, respectively, extending substantially parallel to the first shaft. The first and second opening cylinders each have a peripheral section with a peripheral surface, the peripheral section of the first opening cylinder engaging in a region of rotation of the gripper cylinder to grip a signature on the side to be opened such that the signature can be released again. The first opening cylinder includes a guide element that cooperates with the peripheral surface of the second opening cylinder to aid in conveying the signature when it is positioned between the first and second opening cylinders.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims the priority of European Patent Application No. 05405234.5-2314, filed on Mar. 10, 2005, the subject matter of which is incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     The invention relates to an apparatus for opening a signature or printed sheet and depositing it on a transporting device, the apparatus comprising a continuously rotating gripper cylinder, as well as a first and a second opening cylinder arranged below the gripper cylinder, the shafts of which extend substantially parallel to the gripper cylinder shaft. These opening cylinders respectively open one signature and deposit it with the opened side facing downward onto the transporting device, wherein the first opening cylinder engages with a section of its circumference in the region of rotation for the gripper cylinder to grip a signature on the side to be opened, such that it can be released again.  
         [0003]     An apparatus of this type is disclosed, inter alia, in Swiss patent document CH 408 065. This apparatus, called a depositing machine therein, functions to remove signatures from a stack and transfer them from the continuously rotating gripper cylinder to opening cylinders, which open the signatures and deposit them onto a circulating transporting device, wherein this transporting device can be a gathering chain which is known per se.  
         [0004]     A different apparatus of the aforementioned type is disclosed in Swiss patent document CH 652 103 A. With this apparatus, one opening cylinder is driven with a peripheral speed that is periodically accelerated above and/or delayed below its mean speed. The first opening cylinder passes with a peripheral section and increased speed through the peripheral region of the gripper cylinder and is subsequently delayed, so that the downward speed of the signature reaches a minimum. This is intended to achieve a further increase in the processing. However, this apparatus has the disadvantage that the drive elements are subjected to comparably high wear as a result of the changing loads on the drive. A further disadvantage is that the suction elements of the opening cylinders impact at maximum lag speed with the signatures, thus making it considerably more difficult to maintain the functional safety of the suction opening. Finally, as a result of the delay in the drop speed, large-format signatures cannot be deposited without problems.  
       SUMMARY OF THE INVENTION  
       [0005]     It is therefore an object of the present invention to provide an apparatus of the aforementioned type that avoids the above-mentioned disadvantages.  
         [0006]     The above and other objects are achieved according to the invention wherein according to an exemplary embodiment there is provided an apparatus for opening and F depositing a signature onto a transporting device, the apparatus comprising: a continuously rotating gripper cylinder having a first shaft and carrying at least one signature; and first and second opening cylinders arranged below the gripper cylinder to open the signature carried by the rotating gripper cylinder and deposit the opened signature with the opened side facing downward onto the transporting device, the first and second opening cylinders each having second and third shafts, respectively, extending substantially parallel to the first shaft, the first and second opening cylinders each having a peripheral section with a peripheral surface, the peripheral section of the first opening cylinder engaging in a region of rotation of the gripper cylinder to grip a signature on the side to be opened such that the signature can be released again, the first opening cylinder including a guide element that cooperates with the peripheral section of the second opening cylinder to aid in conveying the signature when it is positioned between the first and second opening cylinders.  
         [0007]     Thus, according to the invention, the peripheral section of the first opening cylinder, which engages in the rotational region of the gripper cylinder, is provided with a guide element that cooperates with the peripheral section of the second opening cylinder to convey a signature that is positioned between the first and second opening cylinders. A movable guide element is therefore provided, which is driven about the periphery of the first opening cylinder for transporting the signature by cooperating with the second opening cylinder. If a signature is transported between the two opening cylinders, the guide element, so-to-speak, forms an extension of the peripheral section of the first opening cylinder. As a result, it is possible to transport even large-format signatures between the two opening cylinders, essentially by providing guidance up to the fold. Since the guide element is movable, it can be displaced to fit against the peripheral section of the first opening cylinder when gripping an additional signature.  
         [0008]     A quieter running apparatus and thus less wear can furthermore be achieved since the first opening cylinder does not have to be accelerated. The uniform driving speed furthermore facilitates the takeover from the gripper cylinder and the deposit of the signatures on the transporting device, for example a gathering chain. The maximum transporting distance can be extended in this way. Owing to the fact that the signature is transferred with uniform speed onto the first and second opening cylinders, the operation of the grippers and the suction openings is ensured even at high speeds. It is furthermore advantageous that the gripper cylinder can be embodied with a comparably small diameter, even if it is provided with two diametrically opposite-arranged grippers.  
         [0009]     According to another exemplary embodiment of the invention, the guide element comprises at least one roller which can be placed against the second opening cylinder for transporting the signature. It is preferable if two rollers of this type are provided, arranged at a lateral distance to each other. As a result, a secure guidance of the signatures during the transport can be achieved with relatively simple means.  
         [0010]     According to exemplary embodiment of the invention, a mechanical drive is used for moving the guide element. A drive of this type can be realized with comparably few and robust parts and results in a secure operation.  
         [0011]     According to a further exemplary embodiment of the invention, the roller movement is controlled by a cam for a control device. A control of this type can be realized cost-effectively and is functionally secure.  
         [0012]     Further advantageous features follow from the following description taken in conjunction with the drawing. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     These and other features and advantages of the invention will be further understood from the following detailed description of the exemplary embodiments with reference to the accompanying drawings.  
         [0014]      FIG. 1  is a three-dimensional representation of the first opening cylinder.  
         [0015]      FIG. 2  is a view of the arrangement according to  FIG. 1 .  
         [0016]      FIG. 3  is a different view of the arrangement according to  FIG. 1 .  
         [0017]      FIG. 4  is a three-dimensional representation of the drive for the guide element.  
         [0018]     FIGS.  5  to  8  show a schematic view of individual stages, depicting the gripping and transport of a signature with the aid of the apparatus. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]     Referring initially to  FIG. 5 , an exemplary embodiment of the invention comprises a gripper cylinder  3  for withdrawing, in a manner known per se, signatures  23  and  23 ′ from a signature stack for a feeder that is not shown herein and transferring these to the opening cylinders  1  and  2 . The gripper cylinder  3  comprises a shaft A, which is driven in counterclockwise direction as shown with the arrow  29 . Separate grippers  28  hold the signatures  23  and  23 ′ by gripping along a fold  23   a  and/or  23   a ′. Grippers  28  are arranged diametrically opposite each other on the gripper cylinder  3 , so that respectively two signatures  23  and  23 ′ can be transported with the cylinder. One of the two signatures  23 ,  23 ′ positioned on the gripper cylinder  3  is gripped by grippers  32  on the first opening cylinder  1  and is pulled away from the gripper cylinder  3 . In  FIG. 5 , the signature  23  is gripped and pulled away by the first opening cylinder  1 . Once the gripper  32  securely grips the signature  23 , the gripper  28  releases the signature  23 , so that the opening cylinder  1  can now transport it. The signature  23  is then transported in a downward direction between the two opening cylinders  1  and  2  and is simultaneously opened up. Finally, the opened signature  23  is dropped onto a transporting device, not shown herein, which may be a conveying chain. The non-shown transporting device can be, for example, a gathering chain of a gathering and wire-stitching machine which can extend approximately parallel to the shaft A of the gripper cylinder  3  and/or parallel to the shafts B and C of the first opening cylinder  1  and the second opening cylinder  2 , respectively. The signatures  23  and  23 ′ may be printed sheets, for example used for producing books, magazines, newspapers and the like.  
         [0020]     FIGS.  1  to  3  show the first opening cylinder  1  in greater detail, with one end in a bearing plate  4 . The bearing plate  4  is fixedly connected with fastening components  5 , only indicated herein, to a machine frame that is also not shown herein. The other end of shaft B is positioned in a similar manner on the machine frame. The shaft B and the shafts A and C are driven in a manner known per se, for example by a drive chain not shown herein.  
         [0021]     At a distance to the bearing plate  4 , the first opening cylinder  1  comprises a first segment  20  and a second segment  21 , which are arranged at a distance to each other and are fixedly connected to the shaft B. Both segments  20  and  21  are provided with a clamping element  22 , for example made of plastic, which operates jointly with a gripper  32  (see  FIG. 5 ) for gripping a signature  23  and/or  23 ′. A signature  23  and/or  23 ′, which must be withdrawn, is therefore gripped at two spaced-apart locations between respectively one clamping element  22  and a gripper  32 . The control of the grippers  32  is known per se to a person skilled in the art and is therefore not explained in further detail herein.  
         [0022]     Each of the two segments  20  and  21  has a section  34 , which essentially extends from the clamping element  22  to a recess  13  (see  FIG. 1 ), wherein the angle between the clamping element  22  and the end of the recess  13  is approximately 120°. Between the clamping element  22  and the recess  13 , the segments  20  and  21  respectively have a peripheral surface  33  that forms a circular arch with the center located on the longitudinal axis of the shaft B, as shown in  FIG. 5 . The rotational direction for shaft B is indicated in  FIG. 1  with an arrow  35 . The two clamping elements  22  thus take the lead and the recesses  13  follow. The peripheral surface  33  extends over an angle that is substantially smaller than 180° and is preferably in the range of 90° to 130°.  
         [0023]     As shown in  FIG. 1 , the two recesses  13  each accommodate one roller that forms a guide element  12 . Both guide elements  12  can be swiveled in the rotational direction and counter to the rotational direction, relative to the segment  20 ,  21 , wherein the radial distance to the longitudinal axis of shaft B remains constant.  
         [0024]     At the distance between a roller for the guide element  12  and the rotational axis of the first opening cylinder  1 , the roller moves fairly precisely along the rotational path for the first opening cylinder  1 . A drive  8  may be used for swiveling the guide elements  12  and/or the rollers, wherein this drive preferably is a mechanical drive. In principle, the illustrated drive  8  can be replaced with a different drive. For example, the transport rollers  12  can also be swiveled with the aid of a suitable motor control, wherein a mechanical drive is preferred. According to  FIG. 4 , the drive  8  is provided with a rod  15  that extends parallel and at a distance to the shaft B, as also shown in  FIG. 1 . One end of the rod  15  is provided with a roller  14  for positioning the rod  15  in a bearing part  36 , such that rod  15  can rotate. A lever  19  is clamped immovably onto the other end of rod  15 , so as to rotate along, wherein a cam roller  18  is attached to this lever. The cam roller  18  travels along a cam  6  which is fixedly connected to the bearing plate  4  and thus to the machine frame. The cam roller  18  is pressed with the aid of a spiral spring  17  onto a running surface  7  of the cam  6 . The spiral spring  17  rests on the rod  15 , as can be seen, and is fixedly connected to a clamping element  37  at one end. The clamping element  9  is fixedly connected to the shaft B and forms an additional bearing for the rod  15 . The clamping element  37  is fixedly connected to the rod  15 . The clamping element  37  can be loosened and turned in order to adjust the tension of spring  17 . The clamping element  37  transmits the tension of the spring  17  to the rod  15 , which then transmits the tension via the single-arm lever  19  onto the roller  18  that is pressed against the surface  7  of the cam  6 , as previously mentioned.  
         [0025]     According to  FIG. 5 , the cam  6  is not round, so that the spacing between the cam roller  18  and the longitudinal axis of shaft B correspondingly changes during the rotation of shaft B, and the rod  15  is rotated around longitudinal axis B via the lever  19 .  
         [0026]     A hook-shaped driver  16  is attached to the rod  15 , such that it can rotate along, at a distance to the bearing roller  14 . During the rotation of rod  15 , the driver  16  is swiveled around the longitudinal axis of rod  15 . As shown in  FIG. 4 , the driver  16  engages between two rotating bearings  24  of a roller holder  10 , arranged at a distance to each other, which serve to position this roller holder such that it can rotate on the shaft B. The roller holder  10  is provided with a yoke  11  on which the two rollers for the guide elements  12  are positioned, spaced apart from side to side, as shown in  FIG. 4 . A roller  25  is positioned on the holder  10  in an intermediate space  38  between the two rotating bearings  24  on the holder  10 , at a distance to the longitudinal axis for shaft B.  FIG. 4  shows that the driver  16  encircles this roller  25 , positioned inside a recess  27 , with its hook-shaped end  26 . If the driver  16  is swiveled, then the roller holder  10  is also swiveled in one or the other rotational direction around the longitudinal axis of the shaft B. In the process, the hook-shaped end  26  grips the roller  25  that is connected to the holder  10 . As previously mentioned, the radial distance for the two transport rollers  12  relative to the shaft B does not change in that case. The rollers for the guide elements  12  therefore move along a circular path, for which the center is positioned on the longitudinal axis of shaft B.  
         [0027]     With the aid of FIGS.  5  to  8 , the mode of operation of the apparatus according to the invention is explained in further detail in the following.  
         [0028]      FIG. 5  shows that the first opening cylinder  1  and the second opening cylinder  2  are arranged below the gripper cylinder  3 . The first opening cylinder  1  is embodied and arranged so that during rotation of gripper cylinder  3  and the first opening cylinder  1 , section  34  of opening cylinder  1  engages in a gap between the signatures  23  and  23 ′ and into the region of the gripper cylinder  3 , as shown, so that it can grip the signature  23  with the grippers  32 , in a manner known per se.  FIG. 5  shows the first opening cylinder  1  immediately after picking up the signature  23  at the open end. The two rollers of the guide element  12  are simultaneously swiveled in clockwise direction, such that they finally come to rest in the recesses  13 , as shown in  FIG. 6 . The rollers  12  also pass through the region of gripper cylinder  3 . According to  FIG. 6 , the grippers  32  in this case are positioned approximately in the three o&#39;clock position.  
         [0029]     With the first opening cylinder  1 , the second opening cylinder  2  is driven simultaneously and moves in counter-clockwise direction, as indicated with arrow  31 . The second opening cylinder  2  has a curved outer surface  39  that forms an approximate semi-circle. In the operating phase shown in  FIG. 6 , the two surfaces  33  and  39  meet, so that the lower end of the signature  23  is gripped with grippers  32  between these two surfaces  33  and  39 , along a projecting edge of a facing leg of a signature  23 ,  23 ′, and is then transported downward. As shown in  FIG. 7 , in the process the leading side  23   b  of the signature  23  is opened, in a manner known per se, for example by means of suction elements not shown herein.  
         [0030]     The two surfaces  33  and  39  jointly transport the signature  23 ,  23 ′ across an angular region of approximately 90°. Once the end of the surface  33  on the segments  20 ,  21  is reached, as shown in  FIG. 7 , the roller guide elements  12  take over the joint further transport. For this, the two rollers are swiveled relative to the shaft B, so that they remain in the illustrated three o&#39;clock position for transporting the signature  23 , wherein the drive  8  is used as explained above. The signature  23  is then transported with the aid of the two rollers and the adjacent peripheral surfaces  39  of the second opening cylinder  2 . For this, the rollers  12  can rest with tension against the peripheral surfaces  39  and can roll off these surfaces. Once the signature  23  has been transported downward far enough, so that essentially the fold  23   a  of the signature  23  has reached the guide elements  12 , the signature  23  that has been opened in the meantime is deposited facing downward onto the transporting device, not shown herein. The two rollers  12  then move with accelerated speed in clockwise direction and finally reach the recesses  13  at the back end of segments  20 ,  21 , as illustrated in  FIG. 6 . As a result, the following signature  23 ′ can be withdrawn by the gripper cylinder  3 , opened and transported in the downward direction. During the complete cycle, the opening cylinder  1  is always driven in the direction indicated with arrow  30 .  
         [0031]     The gripper cylinder  3  and the opening cylinders  1  and  2  are driven uniformly and with correspondingly high smoothness of running. The guide rollers  12  permit transporting a signature  23  and/or  23 ′ along the peripheral sections  39  of the second opening cylinder  2 , up to the ends, even with comparably short peripheral surfaces  33 . As a result, even large-format signatures  23  can be transported with guidance over the complete length, for example over a length of 310 mm. According to  FIG. 5 , the speed of the first opening cylinder  1  when gripping a signature  23  is lower than with a known apparatus having a drive that accelerates and delays, and the signatures  23  can be gripper easier and more securely.  
         [0032]     The invention has been described in detail with respect to preferred embodiments, and it will now be apparent from the foregoing to those skilled in the art, that changes and modifications may be made without departing from the invention in its broader aspects, and the invention, therefore, as defined in the appended claims, is intended to cover all such changes and modifications that fall within the true spirit of the invention.