Abstract:
A device for folding printing copies in a web-fed rotary printing machine includes a folding knife, controls for reciprocatingly moving the folding knife at least approximately in one plane, the controls including a first and a second toggle lever, which, at one of the ends thereof, respectively, are movably attached to frame-fixed parts of the printing machine and at the other ends thereof, respectively, are movably attached to the folding knife, and a rotary element simultaneously actable upon both the first and the second toggle levers for operating the controls; a folder including the folding device; and an assembly including the folder with the folding device.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to a device for folding printing copies. 
     The published German Patent Document 40 18 707 A1 discloses a driving device for folding knives, which is used in polygraphic knife folding machines. Proceeding from an effort to obtain a wide-range adjustment of the height of a folding knife driven by a crank drive, the crank drive including the drive shaft thereof is vertically adjustably disposed. The changes in position of gears of a spur gear transmission associated therewith are assured by supporting rollers, by a connecting lever and by the influence of a pre-stressable compression spring. It is thereby possible to adjust the thus oscillating folding knife over a wide range without affecting the kinematics of the drive. 
     The published German Patent Document 29 17 616 C2 relates to a drive unit for a folding knife for folding planar items. This drive unit includes a linearly acting drive aggregate, which is represented by a traveling-field linear motor that is formed of a reaction part and a secondary part and that is movably mounted in a frame-fixed guide. The movable part of the traveling-field linear motor is arranged so as to be displaceable during the folding cycle, the linear motor being formed so as to be controllable by the sheet to be folded, and devices for dampening and counter-braking the movable part are provided in front of the return or reversal points of the movable part. 
     Due to the use of the linear motor in this improved arrangement, the resulting construction is not suitable for high speeds such as can occur in web-processing rotary printing presses, such as rotary newspaper web presses or jobbing or commercial rotary printing machines. With the improved embodiment according to the aforementioned published German Patent Document 29 17 616 C2, tilting of the folding knife cannot be completely prevented with respect to an off-center folding of sheets. 
     The published German Patent Document 30 46 051 A1 discloses a folding device for web-fed rotary printing presses. A folding device for web-fed rotary printing presses is proposed with which a longitudinal fold extending in the longitudinal direction of printing copies is formed in the printing copy. The longitudinal fold is formed in the printing copy after a cross-fold has been formed therein. A folding knife extending parallel to the transport direction of the printing copies is provided, and is suspended from two driving cranks rotating with the same rotary speed and being moved reciprocatingly. In a lower position thereof, the printing copies to be folded longitudinally are pushed between two driven folding rollers. 
     The suspension of the folding knife from the driving crank is effected via an additional crank. The latter is borne coaxially with pivot pins thereof at the crank pin of the driving crank. The additional crank is driven via a gear transmission at the same rotary speed as that of the driving crank, but in a direction opposite thereto, the crank pin of the additional crank executing a substantially or at least approximately vertical lifting motion. 
     This construction is precise because the gear transmission that is used is associated with a considerable production outlay, particularly with respect to gear teeth accuracy, which is to be produced in an involved and costly manner. This construction is therefore associated with high production costs. 
     SUMMARY OF THE INVENTION 
     Starting from the constructions of the prior art aforedescribed herein, it is an object of the invention to provide a device for folding printing copies which, moreover, generates a linearly extending lifting movement of the folding knife and which is associated with a minimal construction outlay. 
     With the foregoing and other objects in view, there is provided, in accordance with the invention, a device for folding printing copies in a web-fed rotary printing machine, comprising a folding knife, controls for reciprocatingly moving the folding knife at least approximately in one plane, the controls including a first and a second toggle lever, which, at one of the ends thereof, respectively, are movably attached to frame-fixed parts of the printing machine and at the other ends thereof, respectively, are movably attached to the folding knife, and a rotary element simultaneously actable upon both the first and the second toggle levers for operating the controls. 
     In accordance with a special feature of the invention, the folding knife serves for producing a second longitudinal fold in a printing copy in the transport direction of the respective printing copy. 
     In accordance with another feature of the invention, the rotary element is constructed as a double crank. 
     In accordance with a further feature of the invention, the toggle levers are connected to the double crank so that the toggle levers are driven at least approximately in parallel. 
     In accordance with an added feature of the invention, the rotary element is actable via a push rod upon the toggle levers, respectively. 
     In accordance with an additional feature of the invention, the rotary element is constructed as a single crank. 
     In accordance with yet another feature of the invention, the single crank is directly actable upon one of the toggle levers. 
     In accordance with yet a further feature of the invention, the second toggle lever is coupled via a push rod with the toggle lever upon which the single crank is directly actable. 
     In accordance with yet an added feature of the invention, the folding device includes vertical guides wherein the folding knife is guidable. 
     In accordance with yet an additional feature of the invention, the folding knife is movable at least approximately vertically up and down. 
     In accordance with still another feature of the invention, the toggle levers, respectively, are disposed by the one end thereof at a frame-fixed cross bar. 
     In accordance with still a further feature of the invention, the rotary element is cooperatively connected with the toggle levers so that when the rotary element rotates, the folding knife executes a reciprocatory motion. 
     In accordance with still an added feature of the invention, the rotary element is arranged centrally along an imaginary center line of the folding knife, and the two toggle levers are disposed on mutually opposite sides in vicinity of outer edges of the folding knife and are actable upon the folding knife. 
     In accordance with another aspect of the invention, there is provided a folder including a device for folding printing copies in a web-fed rotary printing machine, comprising a folding knife, controls for reciprocatingly moving the folding knife at least approximately in one plane, the controls including a first and a second toggle lever, which, at one of the ends thereof, respectively, are movably attached to frame-fixed parts of the printing machine and at the other ends thereof, respectively, are movably attached to the folding knife, and a rotary element simultaneously actable upon both the first and the second toggle levers for operating the controls. 
     In accordance with a concomitant aspect of the invention, there is provided an assembly including a folder having a longitudinal folding device for forming a second longitudinal fold in printing copies in a transport direction of the printing copies, the folder being preceded by a web-processing web-fed rotary printing machine, and the second longitudinal fold being producible after a cylinder crossfold is formed, the folding device comprising a folding knife accepted at two control members and being movable vertically up and down thereby, the folding knife, in a lower position thereof, serving to push printing copies between two driven folding rollers, the two control members being two driven toggle lever pairs disposed between a frame-fixed cross bar and the folding knife, and a rotary element for simultaneously controlling the toggle lever pairs, the rotary element being rotatable over one rotation thereof per one stroke of the folding knife. 
     The suspension of the folding knife, which is reciprocatingly movable in one plane, from driven toggle levers on frame-fixed parts of the printing machine enables an extremely high speed with great folding precision for a simple and cost-efficient structure by foregoing the use of gearing therein. Due to the drive introduction into the toggle levers, for example, at respective centrally disposed articulating points thereof, assurance is provided that identical motions extending in a horizontal plane are executed at both toggle levers, the motions being followed by a corresponding strictly linear reciprocatory motion of the folding knife. Because gearing or toothed wheel work is not used, the production costs for the folding device proposed in accordance with the invention can be reduced significantly; the linking points or articulating points of the components at the frame-fixed parts of the printing machine, at the rotary element producing the drive, as well as at the upper side of the folding knife, can be realized by bearing bushings, which are simple to produce and which have a long service life. 
     In an advantageous embodiment of the folding device according to the invention, the rotary element driving the toggle levers can be constructed as a double crank. The double-crank component makes it possible to link a number of driven elements at the circumference thereof and can be advantageously realized with respect to the linking points of the transmission elements at the circumference thereof with respect to the occurring knee forces. The two driven toggle levers can be driven in parallel by a double crank, so that identical vertical stroke paths result at both toggle levers. A stroke or lifting rod, which serves as a connecting rod at the same time and which can be manufactured quite simply, can be used advantageously as a power transmission element between the rotating double crank and the toggle levers which can be extended horizontally. By this construction, the rotation of the double-crank rotary element can be transformed into a vertical motion of the articulating point of a bipartite toggle lever. 
     In a further advantageous embodiment of the invention, the rotary element driving the toggle levers can be constructed as a single crank. The single crank can act directly upon one of the toggle levers to be driven. The second toggle lever, which is not directly driven, can be indirectly driven via a push rod proceeding from the directly driven toggle lever. 
     In an advantageous embodiment of the invention, the folding knife can be guided in vertical guides at both short side surfaces, so that no play can occur with respect to the folding knife guide, which would negatively influence the folding precision. 
     In an advantageous embodiment of the driven toggle levers, they have upper and lower parts, respectively, extending symmetrically from a linking point that can be outwardly extended in a horizontal plane, the upper parts being arranged in a frame-fixed cross bar of the folder, and the lower parts of the toggle levers being linked at the upper side of the folding knife that is reciprocable. 
     The folding device according to the invention for forming the second longitudinal fold in the transport direction of the printing copies can be utilized for folders for web-processing rotary printing machines which may be jobbing or commercial wed-fed rotary printing machines presses or newspaper web-fed rotary printing machines, and the folders can be realized as format-variable combination folders or as pinless folders. 
     Other features which are considered as characteristic for the invention are set forth in the appended claims. 
     Although the invention is illustrated and described herein as embodied in a device for folding printing copies, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. 
     The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, wherein: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a fragmentary side elevational view of a vertically movable folding knife, which is suspended from drivable toggle lever pairs; 
     FIG. 2 is an enlarged fragmentary front elevational view, mostly in section, of FIG. 1, showing a rotational element thereof formed as a double crank; and 
     FIG. 3 is an enlarged fragmentary front elevational view of FIG. 1, showing the folding knife suspension with toggle-lever upper and lower parts, respectively, in section. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings and, first, particularly to FIG. 1 thereof, there is represented therein in detail, in a side elevational view, a folding knife accommodated on driven toggle lever pairs. 
     A so-called second longitudinal folding device  2  including a folding knife  3  that is vertically movable at least approximately upwardly and downwardly is provided in an otherwise non-illustrated folder  1 . The folding knife  3  having a folding edge  5  by which it pushes printing copies, which are transported in a copy transport direction  35 , into a nip between two folding rollers  37  (note FIG. 3) otherwise non-illustrated in FIG.  1 . The copy to be longitudinally folded is at rest at the time that it is pushed into the nip between the otherwise non-illustrated folding roller; because the folded spine of the copy is pushed into the nip between the two driven folding copies, the folding copy to be longitudinally folded, on one hand, is transported out of the printing-copy conveying plane of the second longitudinal folding device  2 , and the folded spine, on the other hand, is further formed on the printing copy, due to the folded spine being pushed between the jackets of the two driven folding rollers. 
     The folding knife  3 , the lower folding edge  5  of which pushes the printing copies into the nip between the two driven folding rollers, is accommodated at two transmission elements  10 , which are constructed as driven toggle levers in the exemplary embodiment shown in FIG.  1 . The driven toggle levers  10 , respectively, have an upper part  12  and a lower part  13 , which are connected to one another at an articulating point  11 . The upper part  12  of each toggle lever  10  is accepted in a linking point  8  at a stationary cross bar in the folder  1 , whereas the lower parts  13  of the toggle levers  10  are rotatably accepted in the vicinity of the upper edge  7  of the folding knife  3  in respective linking points  9 . As shown in FIG. 1, double-headed arrows in the vicinity of the articulating points  11  correspond to the horizontal plane wherein the articulating points  11  of the driven toggle levers  10  oscillate. As shown in the exemplary embodiment of FIG. 1, the articulating points  11  are connected via push rods  14  to a rotary element  15 . 
     The rotary element  15  of FIG. 1 can be constructed, for example, as a double crank rotating around a rotational axis  16  in the direction of rotation represented by the curved arrow  17 . The double-crank rotary element  15  which introduces the drive into the transmission elements  10  that are constructed as toggle levers, is driven via a drive which is not otherwise shown in detail. The push rods  14  are rotatably accommodated in mutually oppositely disposed linking points  18  of the push rods  14  at the double crank  15 . 
     A rotation of the double crank  15  in the direction of rotation represented by the arrow  17  effects a rotation of the linking points  18  in a clockwise direction, so that the push rods  14  and, therefore, the articulating points of the driven toggle levers  10  accepting the folding knife  3 , in the course of a complete rotation of the double crank  15 , are synchronously moved towards one another during a half-rotation and are synchronously moved away from one another during the further half-rotation. Therefore, the rotational motion of the double crank  15  is transformed via the push rods  14  into a translational motion of the articulating points  11  in the translational plane (note the double-headed arrows). A strictly vertical motion is thereby impressed upon the folding knife  3 , so that the folding knife  3 , guided at the folding knife guides  4 , executes a vertical upward and downward motion. 
     FIG. 2 shows the double crank  15  of FIG. 1 in greater detail. 
     As shown in FIG. 2, the double crank  15  of FIG. 1 has two outer double crank disks  24 . A double crank center disk  27  is accommodated therebetween. The two outer double crank disks  24 , respectively, are provided with a journal  28  and a drive pin  20 , respectively. A spur gear  21  provided with outer toothing is accepted at the driving pin  20 , which is rotatably received in a bearing  22  in a wall  23 . Via the outer gear teeth thereof, the spur gear  21  combs or meshes with a further drive gear  19 , so that the rotational drive is introduced into the double crank  15  via the drive gear  19 . An outer double crank disk  24  is accommodated at the end of the driving pin  20  located opposite the spur gear  21 . A push-rod yoke  25  is rotatably borne on a pin between the middle double crank disk  27  and the outer double crank disk  24 , one of the push rods  14  of FIG. 1 being rotatably borne on the double crank  15  via the push-rod yoke  25 . The double crank pin  26  represents a linking point  18  as shown in FIG.  1 . 
     The further push rod  14 , which, at the double crank  15 , is also rotatably borne on a double crank pin  26 , is rotatable between the second double crank disk  24  and the double crank center disk  27 . The further double crank disk  24  is borne by a journal pin  28  in a further wall  30 . The journal pin  28  is accepted by a bearing  29 . 
     In a simplified embodiment of the invention of the instant application, a single crank directly driving one of the toggle lever pairs  10  of FIG. 1 can also be used instead of the double crank  15  serving as a rotary element as shown in FIG.  2 . In this embodiment that is not otherwise shown in detail, a connecting rod proceeding from the directly driven toggle lever  10  extends to the oppositely disposed toggle lever  10 , the connecting rod being linked in the articulating point  11  thereof. Therefore, the motion of the further toggle lever  10  is coupled to the motion of the toggle lever  10  that is directly driven via a single crank, so that an up-and-down motion of the folding knife  3  extending in the vertical direction represented by the double-headed arrow  6  (note FIG. 1) results at the guide surfaces  4  thereof in the so-called second longitudinal folding device  2  of the folder  1 . 
     FIG. 3 is a front elevational view, partly in section, of the folding knife drive according to the invention. 
     In a cross bar that is stationarily accommodated in the folder  1 , the upper part  12  of the driven toggle lever  10  is rotatably borne at a linking point  8 . For example, the linking point  8  can be formed by a bolt  31 , which is screwed into the cross bar and is provided with an outer collar. At the opposite end of the upper part  12  of the toggle lever  10 , the latter is rotatably borne at an articulating hinge bolt  32  representing the articulating point  11 . The lower part  13  of the toggle lever, which is rotatably borne with the oppositely disposed end thereof at the linking point  9  in the vicinity of the upper edge  7  of the folding knife  3 , is also borne at the hinge bolt  32  forming the articulating point  11 . The eyes of the upper part  12  and the lower part  13 , respectively, of the driven toggle levers  10  accommodated at the hinge bolt  32  are enclosed by a forked shoulder of a push rod  14 , which is also rotatably borne at the hinge bolt  32 . A translational motion according to the double arrows of FIG. 1 is impressed onto the hinge bolt  32  of the articulating point  11  via the push rod  14  which, though not shown in FIG. 3, is accommodated in linking points  18  at a double crank  15  serving as a rotary element, for example. As a result thereof, the folding knife accommodated at the lower parts  13  of the toggle levers  10  undergoes a vertical motion in the direction of the double-headed arrow  6  (note FIG. 3, for example). The folding edge  5  of the folding knife  3 , therefore, performs a strictly vertical up-and-down motion and, in the downward motion thereof, pushes a printing copy  36 , which is to be longitudinally folded, into the nip between two driven folding rollers  37 , so that the folded spine of the printing copy  36  can be realized therebetween. 
     As shown in FIG. 3, the push rod  14  linked at the hinge bolt  32  of the articulating point or joint  11  of the toggle lever  10  can also be configured as a connecting rod which extends from a toggle lever  10  that is driven via a single crank to the oppositely disposed driven toggle lever  10 . 
     With either of the embodiments according to the invention, i.e., with a double crank  15  as shown in FIG. 2 or with a single crank directly driving a toggle lever  10 , an up-and-down motion extending in vertical direction can be impressed onto the folding knife, so that a strictly linear up-and-down motion can be obtained during a rotation of the double-crank element or the single-crank element of the folding knife lower edge  5  forming the fold, wherein the double-crank element or the single-crank element translates the rotational motion into linear motion.