Acoustics – Sound-modifying means – Housing or enclosure
Reexamination Certificate
2001-02-01
2003-10-14
Nappi, Robert E. (Department: 2837)
Acoustics
Sound-modifying means
Housing or enclosure
C181S205000, C101S232000, C101S480000, C101S216000
Reexamination Certificate
active
06631784
ABSTRACT:
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a device for reducing noise emissions of a machine for printing flat materials, particularly a rotary printing machine wherein the flat materials are transportable over an impression cylinder.
Printing machines of this type, particularly offset printing machines, generate noise in the region of the impression cylinder in printing the flat material and emit this noise into the environment. In this regard, so-called paper-tearing noise is involved, a noise which arises in the printing of paper sheets which are used as flat printing material when they are through-transported between an impression cylinder and an ink applicator element, namely a rubber blanket cylinder, and when they disengage from the ink depositing element. It is possible to reduce noise by primary measures only to a limited extent. But because excessive noise emission from the printing machine is uncomfortable or even hazardous to the operating personnel, the dispersal of airborne noise must be minimized by secondary noise insulation measures. Muffling, on one hand, and damping, on the other hand, are secondary sound insulation measures that come into consideration. Muffling is the conversion of sound energy into heat; it is accomplished by using fibrous or porous absorption materials. Damping is the blocking of sound dispersal; for airborne noise it is preferably achieved by using baffles. Heretofore, the noise arising during the printing of flat material has not been purposefully counteracted as such, but rather only in the context of general sound insulation measures affecting the overall printing unit.
In the German Published Non-prosecuted Patent Application (DE-OS) 34 23 272 A1, a sheet offset printing machine is disclosed including a conveyor mechanism for paper sheets in the form of a chain conveyor having noise emissions which are reduced by using a muffler and a partial encapsulation at the top and bottom sides. The printing machine comprises printing units that have pivoting protective plastic hoods. The protective hoods form an outer cover for the respective printing unit and make it possible to access the elements of the unit easily by swinging the hoods away. In addition, other units of the printing machine such as the drive, delivery and feeder, and the footstep are encapsulated and are constructed damped and, if necessary or desirable, muffled using sound insulation elements. Besides hoods, plates (preferably perforated) which are connected to elements which are formed of muffling material are also provided as sound insulation elements. Fiberglass and foam are suggested muffling materials. What is known as anti-drone material is applied to the walls of the printing machine to attenuate structure-borne noise.
The German Utility Model (DE-GM) 7 325 088 discloses a buckle folding device having a folding unit wherein paper sheets are processed. The paper sheets slide with the aid of transport cylinders along sheet guide rails which are disposed in so-called buckle plates or folding pockets. The buckle plates are surrounded by a swinging multipartite sound insulation mechanism that virtually encapsulates the folding unit. The sound insulation mechanism is formed of steel panel walls which are covered on the exterior side by an open-pored muffling material. In turn, the muffling material is sealed on the interior side by a dustproof foil.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide, by a simple and most economical construction, an optimally effective reduction of the noise emissions arising at the impression cylinder during printing of the flat material.
With the foregoing and other objects in view, there is provided, in accordance with one aspect of the invention, a device for reducing the noise emissions of a machine for printing flat material, wherein flat material is transportable across an impression cylinder, comprising at least one muffling element disposed across a portion of a transport path of the flat material extending along the impression cylinder, directly behind or downline from a nip, as viewed in the direction of the transport path, and at a spaced distance from the impression cylinder.
In accordance with another feature of the invention, the muffling element serves for shielding the nip on at least one side of the transport path of the flat material.
In accordance with a further feature of the invention, the muffling element is affixed to a bearing element.
In accordance with an added feature of the invention, the bearing element is movably mounted.
In accordance with an additional feature of the invention, the bearing element has a hollow interior wherein the muffling element is disposed.
In accordance with yet another feature of the invention, the bearing element is rigid with a footstep for accessing the machine.
In accordance with yet a further feature of the invention, the footstep is pivotably mounted.
In accordance with yet an added feature of the invention, the bearing element comprises a baffling arrangement which is connected to the muffling element.
In accordance with yet an additional feature of the invention, the bearing element is constructed as a baffling arrangement connected to the muffling element.
In accordance with still another feature of the invention, the bearing element is constructed at least partly as a muffling element.
In accordance with still a further feature of the invention, the bearing element comprises a guide element for the flat material, and a muffling element is arranged on a side of the guide element facing away from the impression cylinder.
In accordance with still an added feature of the invention, the bearing element is formed by a perforated plate at least approximately following the curvature of the surface of a jacket of the impression cylinder.
In accordance with still an additional feature of the invention, the device comprises a lateral part for covering an interspace between the muffling element and the impression cylinder at least on one side of the transport path of the flat material.
In accordance with another feature of the invention, the bearing element comprises a lateral part for shielding the impression cylinder at least at one end face thereof.
In accordance with a further feature of the invention, the bearing element comprises a lateral part for shielding a nip on at least one side of the transport path of the flat material.
In accordance with an added feature of the invention, the muffling element is disposed at the lateral part.
In accordance with another aspect of the invention, there is provided a machine for printing flat material, wherein flat material is transportable across an impression cylinder, including a device for reducing the noise emissions of the machine, comprising at least one muffling element disposed across a portion of a transport path of the flat material extending along the impression cylinder, directly behind or downline from a nip, as viewed in the direction of the transport path, and at a spaced distance from the impression cylinder.
In accordance with a concomitant feature of the invention, the machine for printing flat material is an offset printing machine.
The object of the invention is achieved by providing a device for reducing noise emissions wherein at least one muffling element is disposed across a portion of the transport path of the flat material, which extends along the impression cylinder, directly behind a nip and spaced a distance from the impression cylinder.
The portion of the transport path of the flat material which is provided with a sound insulation element is situated directly behind the nip (as viewed in the transport direction) between the impression cylinder and an ink applicator or depositing element, the flat material being transportable through the nip. A portion of the transport path of the flat material extending along the impression cylinder is shielded by at least one muffling element that is disposed at a slight distance from the impression cylinder. The
Conzelmann Daniel
Hieb Christian
Stephan Günter
Greenberg Laurence A.
Heidelberger Drucksmaschinen AG
Martin Edgardo San
Maybeck Gregory L.
Stemer Werner H.
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