Printing – Rolling contact machines – Rotary
Reexamination Certificate
2000-05-22
2001-10-02
Yan, Ren (Department: 2854)
Printing
Rolling contact machines
Rotary
C101SDIG029
Reexamination Certificate
active
06295925
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates generally to flexography and, more particularly, it relates to a method and apparatus for mid-driven infeed for Webtron Model 650 and 750 flexographic printing presses.
2. Description of the Background Art
In the flexographic printing field, a typical flexographic web-fed tag and label press has several sections which are (1) the unwind and infeed section; (2) the printing and drying section; (3) the die-cutting or converting section; and (4) the rewind section. Variations and additions to these sections allow such presses to be adaptable to many different in-line operations.
Two known flexographic web-fed tag and label presses are the Webtron Model 650 and 750 presses made by the Webtron Corporation, 2030 W. McNab Road, Fort Lauderdale, Fla. 33309. In general, these presses have (1) an infeed tension control which isolates the unwinding/infeed section from the printing/drying and converting sections and (2) a total tension zone for both the printing/drying and converting sections thereof. In these presses, proper tension on the web is important to prevent slack, wrinkles, stretch and/or breakage as well as creating proper registration. However, since such tension is created in the converting section and the rewind section, it is difficult to maintain accurate overall tension and registration upstream in the printing/drying section of these presses.
SUMMARY OF THE INVENTION
The present invention is designed to overcome the above limitations that are attendant upon the use of known tag and label presses, and toward this end, it contemplates the provision of a novel method and apparatus for providing for mid-driven infeed for Webtron Model 650 and 750 flexographic printing presses.
It is an object of the present invention to provide a retrofitable attachment which tensionally isolates the printing/drying section from the converting section of the press.
A further object is to provide an apparatus that is compatible with conventional Webtron Model 650 and 750 presses and is generally compatible in physical size, form and configuration with such presses, to be readily adaptable for the same use without disadvantage.
It is a general aim of the invention to provide such an apparatus which may be readily and economically fabricated and will have long life in operation and significantly greater flexibility in use.
It has now been found that the foregoing and related objects can be readily attained in a method and apparatus in accordance with the present invention which utilizes a retrofitable mid-driven infeed unit to control the tension of the web material in the printing/drying section of the flexographic tag and label press.
According to the invention, a flexographic tag and label press for processing a web material following a web path therethrough has a printing/drying section in the web path for providing color on the web material and a converting section in the web path downstream of the printing/drying section for cutting the web material to form tags or labels. The converting section has a driven mechanism which is connected to a mid-driven infeed tension control apparatus in the web path between the printing/drying section and the converting section for use in controlling tension in the web material passing through the printing/drying section.
The mid-driven infeed tension control apparatus has a driving mechanism drivingly engaged by the driven mechanism of the converting section, a pacing roll, a nip roll and an idler roll. The pacing roll is rotatable about an axis and drivingly engaged by the driving mechanism to rotate the pacing roll. The nip roll is rotatable about an axis substantially parallel to the axis of the pacing roll and is adjacent the pacing roll to create a nip therewith through which the web material passes. The nip roll and the pacing roll cooperate to exert a force on the web material passing through the nip. A mechanism is provided to adjust the force on the web material passing through the nip and thus control tension in the web material passing through the printing/drying section. The idler roll is spaced from the nip for guiding the web material into the nip point.
Conveniently, the driving mechanism has a gear adjustably adapted to be drivingly engaged by the driven mechanism of the converting section. The driving mechanism can be a swing gear assembly which includes a swing gear mounted on a swing gear mounting plate. The swing gear mounting plate is adapted to be adjusted to move the swing gear into driving engagement with the driven mechanism of the converting section. The driving mechanism can also include a pacing roll gear mounted on an end of the pacing roll about the axis thereof as well as an intermediate drive gear between the pacing roll gear and the driven mechanism of the converting section.
Ideally, one of the nip roll and the pacing roll has a resilient outer surface for engaging the web material. The other of the nip roll and the pacing roll has a friction finish on an outer surface thereof for engaging the web material.
According to the invention, the mechanism to adjust the force on the web material passing through the nip relatively moves the nip roll and the pacing roll. The force adjusting mechanism includes at least one pneumatically actuated cylinder for moving the nip roll. Air pressure to the at least one pneumatically actuated cylinder can be varied to adjust the force on the web material passing through the nip thus controlling tension in the web material passing through the printing/drying section.
In a further feature of the invention, a pair of spaced apart support plates are provided to which the pacing roll and the nip roll are rotatably mounted. At least one of the pair of spaced apart support plates is mounted adjacent the converting section. In addition, at least a portion of the driving mechanism drivingly engaged by the driven mechanism of the converting section is mounted on one of the pair of spaced apart support plates.
The invention will be fully understood when reference is made to the following detailed description taken in conjunction with the accompanying drawings.
REFERENCES:
patent: 4722275 (1988-02-01), Taguchi et al.
patent: 4878427 (1989-11-01), Washchysnky et al.
patent: 5438926 (1995-08-01), Hudyma et al.
patent: 5490461 (1996-02-01), Beaudoin
patent: 5511712 (1996-04-01), Holm et al.
patent: 5636567 (1997-06-01), Mucha et al.
patent: 5806418 (1998-09-01), Dillinger
patent: 5904094 (1999-05-01), Bredenberg
Roto Press International product line specification sheet for 3500 PF “Primeflex” Series, 3500 VF “Versaflex” Series, 6000 EF “Econoflex” Series and 6500 EC “Econoflex 16” Series.
Roto Press International product specification sheet for VersaFlex Models 3510 & 3513, Aug., 1998.
Webtron Performance Presses 1000, 1013, 1618 & 1620 product specification brochure, Copyright 1994, 3 pages.
Webtron Tag & Label Press 750 HQV product specification brochure, Copyright 1994, 3 pages.
Bria Peter A.
Sarni Michael P.
Sarni/Bria Flexographic LLC
Ware Fressola Van der Sluys & Adolphson LLP
Yan Ren
LandOfFree
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