Sheet feeding or delivering – Feeding – By means to convey sheet
Reexamination Certificate
2001-04-13
2004-03-30
Matecki, Kathy (Department: 3654)
Sheet feeding or delivering
Feeding
By means to convey sheet
C271S258010
Reexamination Certificate
active
06712357
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to document handling systems, and more particularly, to the control of entrance transport element pinch force on documents of various lengths.
2. Discussion
Document handling systems, such as check processors, tag printers and ticket printers, are used to process a variety of documents at high speeds.
FIG. 1
illustrates a conventional system used in a document handling system for stopping a document in a high speed transport so it can be printed on with a printer. As shown, the conventional system typically includes an entrance transport element
12
having a drive roller element
14
and a corresponding pinch roller element
16
. The system also includes a capstan element
18
, a pinch roller element
20
corresponding to the capstan element
18
, an edge sensor
22
, a hammer bank
24
, a print drum
26
, a ribbon
28
, and an exit transport element
30
. The exit transport element includes a drive roller element
32
and a corresponding pinch roller element
34
. In the example shown, MICR amount fields are being printed on a check
10
.
Documents come in a variety of weights and lengths. For example, in check processing, the document lengths range from about 5 inches to 9 inches.
FIG. 1
illustrates the case of a relatively short document
10
. In particular,
FIG. 1
a
shows a document
10
moving toward a print station. As shown, the entrance drive element
14
and pinch roller element
16
are in contact with the document
10
. Typically, a document
10
is moved at high speed up to a print station by the entrance transport element
12
. When the document
10
is in the grip of the capstan element
18
only, the capstan element
18
, and hence the document
10
, is decelerated to the desired stop position, shown in
FIG. 1
b
. For precise positioning, the leading edge
10
a
of the document is sensed by the edge sensor
22
. The edge sensor
22
is a known distance from the desired stop position. The motion of the capstan element
18
is controlled by a single motor (not shown) which is part of a servo loop.
After printing, the document
10
is accelerated up to the speed of the exit transport element
30
by the capstan element
18
. The exit transport element
30
, usually running at high, constant speed, moves the document
10
to other devices for further processing shown in
FIG. 1
c.
As is conventionally known, each of the pinch roller elements
16
,
20
and
34
are normally spring loaded against the entrance
12
and exit
30
drive roller elements and against the capstan element
18
, respectively, in order to provide drive force for the document. A pinch force F
p
is generated by the interaction of the drive roller element
14
or
32
or capstan element
18
and the respective pinch roller element. The pinch force F
p
is applied to the document
10
generally perpendicular to the path of travel.
If the document
10
is short enough, it will not be under the influence of the entrance transport element
12
while the capstan element
18
is decelerating it and holding it in the print position.
However, because some document processing, such as check processing, requires that multiple documents of varying length be processed, reliable document transporting dictates that at least one drive or capstan roller element be contacting the document at all times. As such, drive roller and capstan element spacing needs to be small to reliably transport short documents. Unfortunately, this results in long documents being under the influence of a drive roller and capstan element for a greater period of time, which has an undesirable effect on document handling apparatus performance.
FIG. 2
illustrates printing on a relatively long document
10
′ using conventional methods. As best shown in
FIG. 2
b
, a long document
10
′ is under the influence of the entrance transport element
12
when the capstan element
18
is decelerating and attempting to maintain the document position during printing. To keep the document
10
′ from buckling, from slipping forward during deceleration, and to help the capstan element
18
hold the document
10
′ in position, the small pinch forces F
p
are typically used at the entrance transport element
12
to allow the drive roller element
14
to slip. Unfortunately, this action usually compromises document transport reliability since there is still some force on the document due to the friction between the document
10
′ and the entrance drive roller
14
when the document
10
′ is being driven by
12
with low drive force during its approach to the print station.
SUMMARY OF THE INVENTION
It is an thus object of the present invention to provide shorter stopping and starting times to improve throughput in document processing equipment.
Another object of the present invention is to remove the entrance transport pinch force during document deceleration and stop during document processing, and then return the pinch force just after processing is completed and the document is delivered to the exit transport.
The present invention is directed to an apparatus for providing pinch force control to the entrance transport element in a document handling system. The document handling system includes an entrance transport element comprising a drive roller element and a pinch roller element. A pinch force relief mechanism is coupled to the pinch roller element and is positionable between a pinch force mode and a non-pinch force mode. The apparatus also includes a control element adapted to control actuation of the pinch force relief mechanism between the pinch force mode and the non-pinch force mode. When the control element places the pinch force relief mechanism in the pinch force mode, the pinch roller element is positioned such that a pinch force is exerted on a document. Conversely, when the control element places the pinch force relief mechanism in the non-pinch force mode, the pinch roller element is positioned such that no pinch force is exerted on the document.
Accordingly, depending upon document length, the pinch force is automatically removed from entrance transport element, preventing external forces from affecting the positioning of the document.
Furthermore, a dashpot may be added to better control motion of the pinch force relief mechanism.
REFERENCES:
patent: 4842110 (1989-06-01), Luckhurst
patent: 5239904 (1993-08-01), Yamaguchi et al.
patent: 5249795 (1993-10-01), Nishimoto
patent: 5253862 (1993-10-01), Acquaviva et al.
patent: 5575466 (1996-11-01), Tranquilla
patent: 6065746 (2000-05-01), Tranquilla
patent: 6206368 (2001-03-01), Kobayashi et al.
patent: 6338483 (2002-01-01), Andela et al.
Harness & Dickey & Pierce P.L.C.
Haugland Scott J.
Matecki Kathy
Rode Lise A.
Starr Mark T.
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