Sheet feeding or delivering – Delivering – By pneumatic conveyor
Patent
1990-10-22
1993-06-29
Olszewski, Robert P.
Sheet feeding or delivering
Delivering
By pneumatic conveyor
34156, 226 97, B65H 2924
Patent
active
052227260
DESCRIPTION:
BRIEF SUMMARY
In spite of the most varied devices for suspended conveying working on the principle of the air cushion or the supporting surface, the suspended conveying of material in sheets or bands is still a problem today, especially when thin material with a surface that is sensitive to contact has to be conveyed over paths with different curvatures. In sheet offset printing presses the speeds used today are such that the sheets are caused to flutter. The conveying time from press to storage is so short that the colorant oil cannot dry fast enough, especially with two-sided 4-color printing on smoothed and flattened paper so that smudging of the impression through contact due to fluttering is avoided. Conveying the sheets over aerated conveying surfaces is problematic because the centrifugal forces acting upon the sheet due of different curvatures of the conveying path vary. One-sided support of the sheets against air-cushion nozzles can therefore not prevent contact between sheets and conveying surfaces with certainty. Supporting-surface nozzles also cannot prevent contact because such nozzles blowing in the conveying direction push the sheets together and those blowing against the conveying direction increase the fluttering of the sheets.
In a known device for suspended conveying (DE-GM 60 30 363) the conveyed material is alternately supported on an air cushion and subjected to negative pressure. The device consists of a perforated nozzle body through which air is blown out to constitute air cushions and through which air is alternately aspired. In this manner a strict separation is ensured in conveying direction between zones in which the conveyed material is subjected exclusively to pressure forces and zones in which the conveyed material is subjected exclusively to suction forces. As a result, only material under band traction can be conveyed without contact by such a device. Sheets conveyed free would however be aspired at their forward and rear ends in those zones in which only suction forces take effect, so that contact would be unavoidable.
It is the object of the instant invention to create a device for suspended conveying of material in sheets of bands in which the material can be transported without fluttering and absolutely without contact even with the most varied curvatures of the conveying path.
The invention is based on a process for suspended conveying of material in sheets or bands over a conveying path in which the material is supported on one side on air cushions and is subjected to negative pressure between the air cushions. In this process the problem is solved in that the adjoining air cushions are constituted by free jets streaming past each other and crossing each other at sufficient intervals and in that the negative pressure is built up on the side of the material away from the free jets, said negative pressure reaching through the free jets.
The invention is furthermore based on a device for suspended conveying of material in sheets or bands over a conveying path made up of suspension nozzles supplied by blowing means and arranged at intervals between whose nozzle bodies and the material an overpressure in form of air cushions can be built up by the blowing means and between whose adjoining nozzle bodies means are provided for the production of a negative pressure acting upon the material. In such a device the problem is solved in that free-jet nozzles are formed in rows in the nozzle bodies at intervals and at a distance from the opposite nozzle bodies whereby the free-jet nozzles formed in one nozzle body are offset in direction of the row by approximately one half interval (distance between adjoining free-jet nozzles) in relation to the free-jet nozzles formed in the other nozzle body so that the free jets flow past each other and cross each other and in that suction shafts for the production of the negative pressure are provided between the nozzle bodies to build up the negative pressure acting on the material to produce the negative pressure against the material away from the free-j
REFERENCES:
patent: 3622058 (1971-11-01), Vits
patent: 3680223 (1972-08-01), Vits
patent: 4085522 (1978-04-01), Stroszynski
patent: 4148476 (1979-04-01), Brekell
patent: 4290210 (1981-09-01), Johansson
patent: 4572071 (1986-02-01), Cappel et al.
patent: 4804125 (1989-02-01), Vits
patent: 4836429 (1989-06-01), Nakashima et al.
patent: 4837946 (1989-06-01), Hella et al.
patent: 4843731 (1989-07-01), Vits
patent: 4848633 (1989-07-01), Hagen et al.
patent: 4893416 (1990-01-01), Vits
patent: 5016363 (1991-05-01), Krieger
patent: 5028173 (1991-07-01), Vits
Olszewski Robert P.
Reiss Steven M.
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