Cutting – With product handling means – Means to move – guide – or permit free fall or flight of product
Reexamination Certificate
1998-09-15
2001-01-09
Rachuba, M. (Department: 3724)
Cutting
With product handling means
Means to move, guide, or permit free fall or flight of product
C083S155100, C083S426000, C083S435200
Reexamination Certificate
active
06170371
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and apparatus for the dynamic guidance of flat products, such as flat products which are cut from a continuous web of material by a transversal cutting operation.
2. State of the Art
U.S. Pat. No. 5,029,842 discloses a signature handling apparatus including a first conveyor which sequentially moves signatures to a discharge station. At the discharge station, the signatures are sequentially transferred to a receiving conveyor. To increase the speed at which signatures can move between the first conveyor and the receiving conveyor, one or more corrugations are formed in the signatures to stiffen them. Accordingly, a corrugator assembly is located at the discharge station to stiffen the signatures by forming corrugations which extend between leading and trailing end portions of the signatures. Although the corrugations are only temporarily maintained in a signature, the corrugator assembly is close enough to the receiving conveyor that a corrugation is maintained in the signature, as the leading end portion of the signature moves to the receiving conveyor. That is, the corrugator assembly is spaced from the receiving conveyor by a distance which is less than the distance between the leading and trailing end portions of the signatures.
U.S. Pat. No. 5,107,733 discloses an apparatus for cutting and transporting a paper web in a folding apparatus of a printing press. The apparatus includes a pair of cutting cylinders for cutting web sections from the web, and a transporting device for transporting the web sections away from the cutting cylinders. The first cutting cylinder has at least one cutting anvil, and the second cutting cylinder has at least one cutting knife which meets the cutting anvil at a nip between the cutting cylinders to cut the web moving through the nip. A plurality of strips are supported on each of the first and second cutting cylinders. The strips have positions on the cutting cylinders in which they impress a temporary reinforcing profile onto each of the newly formed leading portions of the web when the strips move through the nip. The reinforcing profile is imparted to each leading portion of the web to assist in guiding the leading portion as it moves from the nip between the cutting cylinders toward the transporting device. In addition to the strips, at least one smoothing surface is also supported on each of the first cutting cylinder and the second cutting cylinder. The smoothing surfaces have positions on the cutting cylinders wherein the smoothing surfaces remove the temporary reinforcing profile from the leading portions of the web when the smoothing surfaces move through the nip.
Despite the existence of signature handling devices as described above, there has been encountered the technical problem that upon severing signatures from a continuous web during its transport to conveyor tapes, positive control of the signature is lost. After the lead edge of the signature is cut, it is fed into the in-running nip of the conveying tapes. However, geometric constraints preclude the conveying tapes from gaining control of a signature until the signature has travelled past the cutting cylinders. A crucial zone for each signature's lead edge therefore extends from behind the cutting nip to a point before the conveyor tapes gain control of the lead edge. The lead edge of the signature is unconstrained during this distance, so it can deviate from a desired straight path into the transport tapes. Particularly, in pinless folders, the signatures often deviate along curved paths instead of following an intended straight path from the cutting cylinders to the conveying tapes. These deviations can result in variations of distance between the signatures conveyed, thereby causing difficulties in further processing the signatures in a pinless folder.
Another drawback of existing cutting cylinder to tape transfers is the signatures' lead edges being blown open. This unintended opening of a signature's leading edge can cause processing jams or product damage, such as dog ears or the like.
Additional corrugating devices, such as those disclosed in U.S. Pat. No. 5,107,733, have also been used with cutting cylinders. Furthermore, the use of electrostatic tackers upstream from the cutting cylinders has been proposed to address the problems which occur during the transfer of signatures. However, these solutions cause other problems, and render the signature transfer area between cutting cylinders and conveyor tapes a rather sensitive area within a pinless folder.
SUMMARY OF THE INVENTION
Given the state of the art as described above, and the associated problems encountered in the technical field, it is accordingly an object of the present invention to provide positive control of signatures severed from a web of material while the signatures travel between a cutting nip and an in-running nip of conveyor tapes.
A further object of the present invention is to maintain relatively constant distance between signatures severed from the web of material during their transport through the conveyor tapes.
Another object of the present invention is to prevent lead edges of signatures from blowing open during their transport.
According to exemplary embodiments of the present invention, an apparatus for transporting signatures within a folding apparatus comprises at least one pair of cooperating cutting cylinders, each of said cutting cylinders having at least one of a knife and an anvil bar; a conveying plane which extends substantially vertically during operation; and a first conveyor assembly and a second conveyor assembly, said cooperating cutting cylinders being integrated into paths of conveying elements of said first conveyor assembly and said second conveyor assembly for seizing a web of material prior to a cutting operation performed by said cooperating cutting cylinders.
Exemplary embodiments also relate to a method for transporting signatures of a folding apparatus comprising the steps of conveying said web of material through a transverse cutting plane using at least first and second conveyor assemblies which seize said web of material in both an input area and an output area of said transverse cutting plane; and actively driving said seized web of material into a finger-shaped guide located downstream of said first and second conveyor assemblies.
Exemplary embodiments according to the present invention allow for positive control of the web from both sides thereof, prior to severing signatures from the leading edge of the web of material in the cutting nip. Since longitudinally folded signatures are seized and kept together, blowing open of signature lead edges is reduced and/or eliminated. Further, since an area extending from the cutting nip to an in-running nip of conveyor tapes is bridged by the conveyor assemblies, a deviation of signature lead edges is eliminated, and a constant distance between each sequential signature is maintained.
According to further details of the present invention, the conveying elements can either be arranged in groups of any number (e.g., two or three), each group of conveying elements being spaced apart from the following group of conveying elements—and/or the conveying elements can be individually arranged on the paths of the conveyor assemblies.
The arrangement of conveying elements in groups of at least two or three conveying elements has advantages in the lower region of the conveying plane, at the out running nip thereof. The second and/or third conveying elements of each group exert a positive drive upon signatures when travelling into a lower pair of belts.
The conveying elements—either arranged in groups and/or individually—are connected to each other by linking elements forming a closed loop on each conveyor assembly. The conveyor elements can, for example, be cross bars extending over the width of the web of material, the cross bars having guiding discs spaced apart from each other. Alternately, the conveyor elements can, for
Belanger James Richard
Cote Kevin Lauren
Curley Richard Daniel
Burns Doane , Swecker, Mathis LLP
Heidelberger Druckmaschinen AG
Rachuba M.
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