Abstract:
To permit high-speed operation of a longitudinal folding apparatus in which a folding blade engages between two folding rollers (11), the folding blade and the folding rollers of the folding apparatus (7) are made sufficiently long to accomodate a plurality of essentially immediately adjacently positioned printed products. The printed products are supplied by a transport system (1, 20) with spacing by about the length of a product therebetween, and, in accordance with the invention, are repositioned immediately adjacent each other, with gaps between immediately adjacent products longer than the spacing between products as supplied. Repositioning is effected by removing selected products from the transport system, guiding them in an auxiliary transport path formed by the circumference of a gripper drum, or of an auxiliary belt system, located along the transport system and repositioning the products, after transporting in the auxiliary transport path, at the selected position back on the transport system and immediately adjacent a subsequently supplied product which was not deflected into the auxiliary transport path.

Description:
REFERENCE TO RELATED PUBLICATION 
     German Published Patent Application DE-AS No. 1 204 689. 
     The present invention relates to folding apparatus, and more particularly to high-speed folding apparatus to form a transverse fold in a plurality of printed products, simultaneously, received for example from a rotary printing machine, or longitudinal folding apparatus coupled thereto. 
     BACKGROUND 
     Increasing the output speed of rotary printing machines is sometimes limited by the output apparatus to which the machines are coupled. One such output apparatus is a longitudinal folding apparatus. Longitudinal folding apparatus usually are so constructed that the material to be folded is passed transversely with respect to its supply direction through folding rollers. It is important that the rear or trailing edge of the product to be folded, during the folding operation, which no longer moves in the supply direction, has left the plane of the next product to be folded before the next product to be folded arrives. The time which is required for the product which is being folded until its trailing edge leaves the plane of the supply or transport belts--which are usually provided--is considerable and, upon high-speed production, the transport system may pass over a substantial distance. During that time, and as this distance is passed, a subsequent printed product may be supplied. The subsequent printing product, however, must be prevented from engaging or impinging on the product which is just being folded since, otherwise, the products may be damaged, or shifted in position, that is, the product then being folded may no longer be folded along the predetermined folding line. 
     It has previously been proposed--see the referenced German Patent Publication DE-AS No. 1 204 689--to split the stream of the products to be folded to two paths, each one being directed to an individual longitudinal folding apparatus. This solution, while providing for high-speed output, is expensive since it requires duplication of the folding apparatus, additional space for the additional folding apparatus, and for the additional transport path. 
     THE INVENTION 
     It is an object to provide a folding apparatus permitting longitudinal folds which is suitable for high production speeds while requiring only small modification of existing apparatus and little or no additional space. 
     Briefly, an auxiliary transport path is formed on or above or adjacent the main transport path which supplies printed products to a folding apparatus, the auxiliary transport path having a path length which is longer by at least the length of one of the products than the direct transport path. The auxiliary transport path receives, for example, every second or every third sheet or product to be folded, and redeposits that sheet, at a different position along the main transport path. The folding apparatus itself is made at least as long as the overall length of adjacently positioned products which are supplied thereto after the products in the auxiliary transport path have been returned to the main transport system. 
     The invention utilizes the feature customary in many high-speed transport systems that the printed products, as derived for example from a rotary printing machine, are spaced along the transport path with gaps which are, usually, about the length of the printed product itself, usually slightly more. The invention, thus, provides for repositioning of the printed products so that at least two of them will then be located adjacent each other, with a longer gap between adjacently positioned products, the adjacently positioned products then being folded in a common folding apparatus which, however, is axially longer than the one originally provided, for example in accordance with the prior art. 
     The system has the advantage that mere repositioning of the products being supplied to the longitudinal folding apparatus permits saving of a second individual folding apparatus and the associated transport system, including all space therefor. The relocation of the printed products on an existing belt can be carried out easily and simply by well-known apparatus customary in the printing industry. 
    
    
     DRAWINGS 
     FIG. 1 is a schematic side view of one embodiment of the folding and supply apparatus in accordance with the present invention; 
     FIGS. 2, 3 and 4 are fragmentary illustrations of a portion of the system of FIG. 1, showing the system in different operating phases; 
     FIG. 5 illustrates another embodiment of the invention; 
     FIG. 6 illustrates the apparatus of FIG. 5 in a different operating phase; and 
     FIGS. 7, 8 and 9 are schematic illustrations showing possibilities for repositioning of printed products on a transport path. 
    
    
     DETAILED DESCRIPTION 
     A transport system 1, which, for example, is constructed of a plurality of adjacently positioned narrow belts 2 and 3 beneath the products as well as upper hold-down belts 4 and 5 supplies printed products 6 to a longitudinal folding apparatus 7. Rather than using separate narrow belts 2, 3, continuous lower belts having the extent of the belts 2, 3, can be used. The transport system 1 feeds products 6, 6a, 6b, 6c . . . in the direction of the arrow a. The products 6, 6a . . . are received from a transverse folding apparatus--not shown--which, in turn, is coupled to a rotary printing press (not shown) and are supplied in distances which are about the length of one of the products. The belts 3, 5 extend through the longitudinal folding apparatus 7. 
     The longitudinal folding apparatus 7 is constructed, basically, as well known and includes a carrying cylinder 8 on which a folding blade 9 is pivotably secured. The folding cylinder 8 is journaled between two side walls 10. Two folding rollers 11 are located in the side walls 10. The folding rollers 11, of which only the forward one is shown, are located behind each other, with respect to the plane of the drawing. The length of the folding rollers 11 and of the folding blade 9 is so dimensioned that, at one time, at least two of the printed products 6 can be folded. Thus, the folding rollers 11 and the blade 9 have a length which corresponds at least to the overall length of adjacently supplied products, typically two adjacently supplied products, including a clearance space between the respective products. The longitudinal folding apparatus 7 further includes a fixed stop member 12 for the leading or forward product--in the direction of the feed, arrow a--and further a movable stop 13 for the rearward product. The stop 13 is longitudinally movable up and down, that is, in the direction of the arrow b, or counter the direction, by a suitable reciprocating mechanism, for example a rotary eccenter 15, moving the stop 13 up and down, the stop 13 being retracted by a spring 14 coupled thereto. The stop 13 is longitudinally guided in a suitable guideway, not shown, and of any standard construction. Upon rotation of eccenter 15, stop 13 is moved, in dependence on the supply speed, and in synchronism therewith, of the transport belt system 2, 3 into the plane of the belt system 2, as seen in FIG. 1, and thereafter pulled away from that plane to permit the next product to be fed to the stop 12, then to be moved upwardly to separate the next two products from each other. 
     In accordance with a feature of the invention, an auxiliary path is provided for selected products, by switching selected products into the auxiliary path. As seen in FIG. 1, the auxiliary path is defined by the circumference of a deflection drum 16, which is rotatably journaled above the transport belt 2. The deflection drum 16 is driven by a suitable drive--not shown--with a circumferential speed which corresponds to the speed of the transport system 1. The circumference of the drum 16 corresponds approximately to three times the length of one of the products 6. The drum 16 includes three rows of grippers 17, 18, 19 which are pivotably located at the circumference thereof. 
     Operation: As seen in FIG. 1, the grippers 17 grip a product 6a, pick up the product--see FIG. 2--and remove it from the transport path 1, and thus move the product 6a in the auxiliary path. As the drum 16 rotates, the transport belts of the transport system 1 feed the next product 6b in the direction of the arrow a. As best seen in FIGS. 3 and 4, the next product 6b will pass beneath the drum 16, since the grippers 18, 19 in those positions, are controlled to match the circumference of the drum 16, and do not pick up any product. After the product 6b has passed beneath the drum, the drum 16 will have reached the position of FIG. 4, and the product 6a is again returned to the transport system 1. Only a small gap will remain between the products 6b, 6a--that now being the position in which they will be transported on the system 1--just enough in order to permit the movable stop 13 on the folding apparatus 7 to separate the two products. Starting from the position shown in FIG. 4, the rows of grippers 18 then will grip the next product 6c, deflect the product around the drum 16 and deposit the product 6c behind the then following product 6d (not shown), product 6d being fed along the path 1 without deflection. 
     The repositioning of the respectively staggered and spaced products which are supplied on the belt system 1 is best seen in FIG. 7. Product 6a is deflected and repositioned behind product 6b, thus forming an essentially continuous path between products 6b, 6a--in that order--for feeding to the folding apparatus 7, closely adjacent each other. Thereafter, the deflection drum 16 will grip the product 6c, and deposit it behind the product 6d. Consequently, a distance will be formed between the products 6a and 6d which is about twice the distance between any two products initially supplied by the belt system 1. Consequently, the folding process of the two, now quite closely adjacent products 6a, 6b will be longer until the leading edge of the next two closely positioned products 6d, 6c runs between the folding rollers 11 and the folding blade 9. This insures that the trailing edge of the product 6a reliably has been pulled out of the way of the leading edge of the following product 6d, when the product 6d reaches the region of the folding rollers 11. 
     The system is versatile and can be readily changed; as described, the deflection drum 16 deflects alternately supplied products and deposits the so deflected products behind the intermediate ones which are fed, undeflected, through the transport path 1. The longitudinal folding apparatus, thus, will receive two closely spaced products, for simultaneous folding and handling, behind which two products will be a gap or distance to the next subsequent two products of not quite double the length of the products. 
     The deflection drum can be so arranged that the grippers thereof are controlled to grip, for example, each third product, as shown in the schematic arrangement of FIG. 9. First, a product 6u is gripped by the grippers 17 of the deflection drum 16 and, after one revolution, is deposited behind the product 6v, and immediately adjacent the product 6w. The drum 16 then revolves by one complete revolution without picking up a product from the belt system 1. Consequently, the products 6v, 6u and 6w are supplied, sequentially, to the longitudinal folding system 7 and can be folded in one operating folding step. In this arrangement, the folding apparatus 7 must have a length to accept three products, and two separating elements 13 are needed. 
     After one revolution of the drum 16, without having deflected or gripped any products, the grippers 17 then grip the product 6x, and deposit it after a further revolution behind the product 6y, and immediately in front of the product 6z. The next folding operation for the products 6y, 6x, 6z will again occur simultaneously, similar to the arrangement described in connection with the products 6z, 6u, 6w. This arrangement, of course, presupposes that the folding blade 9 and the rollers 11 are sufficiently long to be able to accept three products at the same time. The stops 12, 13 are not strictly necessary, but desirable. If the stops 12, 13 are used, the system should be so arranged that the spacing of the trailing edge of one product to the leading edge of the next product be slightly longer than the length of a product. This may require slight increase of the spacing between the products, which is readily obtainable by suitable adjustment of a previously connected transverse folding apparatus, or output belt systems from a rotary printing machine. 
     Embodiment of FIGS. 5 and 6: The belt system 20 is constituted of a plurality of adjacently located narrow lower belts 21, 22, and upper belts 23, 24. Products 25, 25a, 25b, 25c, . . . are transported in the direction of the arrow c from a transverse folding system (not shown) to a longitudinal folding system 7, not shown in FIG. 5, and similar to the longitudinal system 7 illustrated in FIG. 1. 
     The upper belts 23 are lifted off the lower belts 21 during a zone defined by the distance between deflection rollers 26, 27. Within this zone, a plurality of narrow deflection rollers 28 are located adjacent each other, which are guided about rollers 29, 30, 31, 32. The belts 28 are driven with the same speed as the belt of the system 20, so that the upper run 28a of any belt 28 runs in the same direction as the deflected run 23a of a belt system. Two transport paths are provided for products which arrive in the direction of the arrow c, by a deflection switch 33. One of the paths is straight through along the lower belts 21; the other path is first along the lower belts 21, and then along and beneath the upper belts 23, and the upper run 28a of the deflection belt system 28. The other path, then, is between the deflected run 23a of the upper belt 23 and the upper run 28a of the belts 28, then at an angular inclination along the path defined by the deflection rollers 31, 32 and back to the lower belts 21. 
     The deflection switch 33 controls the path which the respective products are to take, deflection switch 33 being located just behind deflection roller 26, as best seen in FIG. 5, in which the deflection switch is shown in the position in which a product is deflected in the upward or auxiliary path. The deflection switch, when moved counter the direction of the arrow d, permits deflection of a product into the auxiliary path; upon pivoting the deflection switch in the direction of the arrow d, a straight-through path of the products on the lower belts 21 will be commanded. To hold the products upon straight-through passage against the lower belts 21, further contact belts 35, guided about rollers 34, are provided. The speed of the belts 35 is the same as the speed of the belts 21, and 23, respectively. 
     The deflection rollers 26, 27, 29-32 are so arranged that the length of the auxiliary supply path of the belts 23 between the switch 33, which defines a removal position, and the return position in the region of the deflection roller 27 is longer by about the length of one product than the length of the supply path of the belt system between the removal position at the switch 33 and the resupply position at the roller 27. 
     The arrangement as illustrated in FIG. 5 shows one operating condition, in which the product 25a is fed between the belts 28 and the deflected run 23a of the upper belts 23. As soon as the trailing end of the product 25a has left the switch 23, switch 23 is moved in the direction of the arrow d in the undeflected position, so that the next product 23b will be fed in straight-through line on the belts 21. Since the feed length of the auxiliary path of the deflection belts 28 is longer by about the length of one product than the feed path of the lower belts 21--as best seen in FIG. 6--product 25a is fed shortly in advance of the product 25b back to the lower belts 21, at the return position just before the deflection roller 27. As small distance will be left between the products 25a, 25b, just sufficient in order to permit the movable stop 13 of the longitudinal folding system 7 to be inserted between the two products 25a, 25b. The switch 23 will be reset immediately after the product 25b has passed the switch 33 into the position of FIG. 5, so that the next arriving product 25c is again fed into the auxiliary path--see FIG. 5. 
     The feed diagram is best seen in FIG. 8, which shows that every other product 25a, 25c is deflected and again redeposited in advance of the subsequent product 25b, 25d, respectively. Thus, two products will be immediately adjacent each other, and fed in that position to the longitudinal folding apparatus 7. A distance of about double the length of the products will obtain behind the two closely adjacent products until the next pair of products arrives. 
     Various changes and modifications may be made, and any features described herein may be used with any of the others, within the scope of the inventive concept.