Winding – tensioning – or guiding – Convolute winding of material – With particular drive
Reexamination Certificate
2002-01-18
2002-10-15
Jillions, John M. (Department: 3654)
Winding, tensioning, or guiding
Convolute winding of material
With particular drive
C242S530300, C242S909000
Reexamination Certificate
active
06464162
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention-relates to a web processing system for slitting a wider web into a plurality of narrower webs for use as photographic photosensitive webs (films), and winding the narrower webs.
2. Description of the Related Art
Generally, web processing systems have a web slitting device for slitting a wider web of film, paper, metal foil, or the like into a plurality of narrower webs, and a winding device for winding the narrower webs.
The web processing systems also have a side edge delivery device for delivering side edges that are severed off the wider web when it is slit. Heretofore, the side edge delivery device comprises delivery rollers and nip rollers for nipping and delivering the side edges. For details, reference should be made to Japanese laid-open patent publication No. 8-257990, for example.
When the wider web is slit into the narrower webs by rotary blades, it is necessary for the side edge delivery device to apply a predetermined level of tension to the side edges in order to give highly accurate transverse dimensions to the narrower webs.
If the side edges were not tensioned or were tensioned excessively, then the wider web that reaches the rotary blades would be flexed, resulting in a reduction in the accuracy of the transverse dimensions of the narrower webs.
One conventional side edge delivery device which is capable of applying tension to side edges (hereinafter referred to as “conventional side edge delivery device”) is disclosed in Japanese laid-open patent publication No. 10-6126, for example.
The conventional side edge delivery device comprises nip rollers that are pressed against delivery rollers under a constant pressure by cylinders, and motors operatively coupled to the delivery rollers by respective clutches. The clutches are supplied with exciting currents that are variable to apply a desired tension to the side edges.
As described above, for imparting a desired tension to the side edges, the cylinders are connected to the respective nip rollers and the clutches are operatively coupled between the delivery rollers and the motors. However, the clutches are responsible for an increase in the manufacturing cost of the conventional side edge delivery device.
The motors are rotated at a constant speed at all times, and the exciting currents of the clutches are controlled to set the side edge tension to a desired value. Therefore, while the slitting process is being suspended, the clutches slip at an increased speed, and hence tend to generate an increased amount of heat.
Winding devices that are in practical use for winding narrow webs having a small thickness ranging from 10 to 20 &mgr;m, e.g., ½-inch and 8 mm magnetic tapes, have a tension fluctuation ratio of ±5% or less.
However, winding devices for winding wide webs having a large thickness ranging from 100 to 150 &mgr;m, e.g., photographic photosensitive webs (films), with a low tension fluctuation ratio, have not yet been developed in the art.
As shown in
FIG. 15
of the accompanying drawings, a conventional film winding device
500
comprises a drive shaft
504
with an air tube
502
disposed therein, and a winding core
512
rotatably mounted on the drive shaft
504
by bearings
506
,
508
, for winding a film
510
therearound. The conventional film winding device
500
also includes a displacement transmitting member
516
disposed around the air tube
502
within the winding core
512
and having a felt pad
514
mounted on a radially outer surface thereof.
When compressed air is introduced into the air tube
502
, the air tube
502
is expanded to displace the displacement transmitting member
516
radially outwardly for thereby pressing the felt pad
514
against an inner wall surface of the winding core
512
for slipping contact therewith.
The torque that is generated when the felt pad
512
slips against the winding core
512
is used as a tension applied to the film
510
when the film
510
is wound around the winding core
512
.
However, the conventional film winding device
500
is disadvantageous in that the tension applied to the film
510
is not stable and the tension fluctuation ratio can only be lowered to about ±15% even if the conventional film winding device
500
is well conditioned. Furthermore, the conventional film winding device
500
is unable to produce large tension because of its principles of operation. The maximum tension that can be generated by the conventional film winding device
500
is about 10 N at the most, when the width of a narrow web to be wound is 35 mm, for example. If more tension is produced, then the film
510
that is wound tends to be deformed due to the heat. Moreover, since the air tube
502
is mounted in the drive shaft
504
and the felt pad
514
is attached to the radially outer surface of the displacement transmitting member
516
, the conventional film winding device
500
is complex in structure and its maintenance needs to be carried out by skillful operators.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a web processing system for winding relatively wide webs having a large thickness ranging from 100 to 150 &mgr;m, e.g., photographic photosensitive webs (films), with a low tension fluctuation ratio of ±5% or less, while producing large tension easily and stably, the web processing system being constructed for easy maintenance.
Another object of the present invention is to provide a web processing system which can be manufactured inexpensively and is capable of slitting a wider web into a plurality of narrower webs having highly accurate transverse dimensions.
According to an aspect of the present invention, a winding device of a web processing system has a drive shaft having a flange, and a holder rotatably mounted on the drive shaft in covering relation to the flange, for winding the web therearound, the holder comprising a first torque adjustment unit rotatably mounted on the drive shaft and having a surface disposed in facing relation to a surface of the flange, the first torque adjustment unit supporting a plurality of magnets on the surface thereof, and a second torque adjustment unit rotatably mounted on the drive shaft and having a surface disposed in facing relation to an opposite surface of the flange, the second torque adjustment unit supporting a plurality of magnets on the surface thereof.
When the relative position of the first and second torque adjustment units is varied, the density of magnetic fluxes produced between the first and second torque adjustment units is varied.
When the drive shaft is rotated about its own axis, the flange positioned between the first and second torque adjustment units cuts the magnetic fluxes produced between the first and second torque adjustment units, generating eddy currents in the flange. Secondary magnetic fluxes produced in the flange by the eddy currents and the magnetic fluxes produced between the first and second torque adjustment units attract each other, producing a torque substantially proportional to a slipping speed, for example.
According to another aspect of the present invention, a winding device of a web processing system comprises a drive shaft having a ring, an annular conductor pressed against and secured to an outer circumferential surface of the ring, and a holder rotatably mounted on the drive shaft in covering relation to the ring, for winding the web therearound, the holder supporting on an inner circumferential surface thereof a magnet row of a plurality of magnets, the magnet row facing the annular conductor.
When the drive shaft is rotated about its own axis, the annular conductor cuts the magnetic fluxes produced between magnet rows, generating eddy currents in the annular conductor. Secondary magnetic fluxes produced in the flange by the eddy currents and the magnetic fluxes produced between the magnet rows attract each other, producing a torque substantially proportional to a slipping speed, for example.
According to stil
Kuwabara Fujio
Sanda Akihiro
Watanabe Kenji
Yamazaki Tsuneo
Fuji Photo Film Co. , Ltd.
Jillions John M.
Sughrue & Mion, PLLC
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