Information
-
Patent Grant
-
6244591
-
Patent Number
6,244,591
-
Date Filed
Friday, September 24, 199925 years ago
-
Date Issued
Tuesday, June 12, 200124 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Foley & Lardner
- Kleinke; Bernard L.
-
CPC
-
US Classifications
Field of Search
US
- 271 184
- 271 185
- 271 186
- 271 902
- 271 225
-
International Classifications
-
Abstract
A shunt is described for reversing the direction of conveyance of a document or the like. The document is accepted by a front-end roller and supplied to a reversing roller. As soon as the trailing rear edge of the document has left the front-end roller, the direction of rotation of the reversing roller is reversed and this guides the document, with the rear edge leading, to an output roller which is disposed offset in height relative to the front-end roller and outputs the document in the opposite direction.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
REFERENCE TO A “MICROFICHE APPENDIX”
Not Applicable
BACKGROUND OF THE INVENTION
1. Technical Field
The field of the present invention is transporting sheets in an office machine. More specifically, the invention relates to a shunt for reversing the conveyance direction of a document or the like.
2. Background Art
With office machines such as printers, copiers and the like, it is frequently desirable to reverse the conveyance direction of a document. The document is, for example, a paper sheet or the like provided with recordings. Reversing the document needs to be accomplished such that the document is transported first with its front edge leading, and is then further conveyed with its rear edge leading.
Others have addressed reversing the conveyance of a sheet of paper. For example, it is known from DE 32 17 115 A1 to accept the leading edge of an arriving document with a reversible roller pair whose direction of rotation can be reversed. In front of the reversible roller pair is disposed a pivotable guidance roller. When the document has been pulled in by the reversible roller pair such that the document's rear edge has reached the guidance roller, the direction of rotation of the reversible roller pair is reversed and the guidance roller is pivoted such that the document is steered by the guidance roller into the desired direction for further conveyance with the document's rear edge leading. This known shunt has the disadvantage that a succeeding next document can only be supplied to the reversing roller pair when the preceding document has been completely output by the reversing roller pair. Consequently the shunt hinders the conveyance of the documents and limits the continuity of document conveyance.
In another known example, DE 195 06 181 A1 shows a shunt where a sheet is supplied by front-end rollers to a reversible roller pair whose direction of rotation is reversible. The reversible roller pair accepts the sheet supplied by the front-end rollers and conveys it until the rear edge of the sheet is released by the front-end rollers and has been pulled over a wedge-form shunt element. The direction of rotation of the reversing roller pair is subsequently reversed such that the rear edge of the document is now leading and is transported past the shunt element to the output rollers. As soon as the output rollers have taken hold of the sheet and are conveying it in the output direction, the reversing roller pair is opened such that the next succeeding sheet can be guided by the front-end rollers into the open gap of the reversing roller pair. It is thereby possible to guide the particular succeeding next sheet into the reversing roller pair before the preceding sheet is completely pulled out of the reversing roller pair. The front-end roller and the output roller cooperates with a common pressure roller such that the drawing-in speed of the front-end roller and the output speed of the output rollers are, by necessity, equal. The output speed thereby limits the drawing-in speed of the front-end roller.
Thus, there exists a need for a shunt which makes possible a closer continuity sequence of the conveyed documents.
SUMMARY OF THE INVENTION
In a shunt for reversing the conveyance direction of a document, the document is completely drawn in by a front-end roller pair and are output again in the opposite direction via a separate output roller pair. After the front-end roller pair, the leading edge of the document is accepted by a reversing roller. After the document is released from the front-end roller pair, the direction of rotation of the reversing roller is reversed. The document is then transported to an output roller pair which continues to transport the document. A pressure roller, which can be pivoted toward the document, holds the document in engagement with the reversing roller. When the reversing roller has conveyed the document such that its rear edge, now leading, has been taken hold of by the output roller pair, the pressure roller can be pivoted away from the revering roller so that a succeeding document, which has already been taken hold of by the front-end roller pair, can be guided between the reversing roller. The pressure roller can thereby be pivoted away. While the output roller pair outputs the preceding document in the opposite direction, the front-end roller pair can already be drawing in the succeeding document.
Advantageously, successive documents can thus overlap preceding documents within the shunt. In such a manner a closer sequential continuity of document conveyance is possible. The output roller pair and the front-end roller pair are independent of one another so that, for example, the output roller pair can guide the document away at a higher velocity than that achieved by the front-end rollers. The shunt thereby does not introduce a delay to document conveyance.
BRIEF DESCRIPTION OF DRAWINGS
The above mentioned and other objects and features of this invention and the manner of attaining them will become apparent, and the invention itself will be best understood by reference to the following description of the embodiment of the invention in conjunction with the accompanying drawings, wherein:
FIG.
1
. is a schematic vertical section showing the shunt made in accordance with the present invention in the acceptance position.
FIG. 2
is a schematic of the shunt of
FIG. 1
showing the shunt in the reversing position, and
FIGS. 3-4
are schematic of the short of
FIG. 1
showing the overlapping of acceptance and output of two successive documents.
BEST MODE FOR CARRYING OUT THE INVENTION
Referring now to
FIG. 1
, there is shown a shunt made in accordance with the present invention. The shunt receives a sheet-form document
10
from an office machine, for example a printer, which the document
10
supplied to the shunt from the left as shown in FIG.
1
. In the document supply path is disposed a first sensor
12
. As indicated by the arrow
11
in
FIG. 1
, the arriving document
10
arrives at a front-end roller
14
. The front-end roller
14
is driving at the circumferential speed V
1
. A pressure roller
16
cooperates with the front-end roller
14
in order to bring the document
10
and the front-end rollers
14
into frictional engagement. Those skilled in the art will recognize that the front-end roller
14
can comprise a cylinder, extending over the width of the document, or several rollers disposed on a common shaft.
An output roller
18
, offset in height, is disposed below the front-end roller
14
and axis-parallel with it. The output roller
18
is drivable with the circumferential speed V
2
, and cooperates with a pressure roller
20
. The output roller
18
can also comprise a continuous cylinder or several discrete rollers disposed on a common shaft. Typically, the circumferential speed V
2
will be greater than the circumferential speed V
1
.
The pressure rollers
16
and
20
are each freely rotatable and supported on legs of a brace
17
. The pressure rollers
16
and
20
are held in contact on the front-end roller
14
and the output roller
18
by a spring
19
. The pressure roller
16
consequently rotates at speed V
1
while the pressure roller
20
rotates at speed V
2
.
A drivable reversing roller
22
is disposed axis-parallel with the front-end roller
14
and with the output roller
18
. More specifically the reversing roller
22
is positioned on the side facing away from the arriving side of the front rollers behind the front-end roller
14
and the output roller
18
and, spaced apart therefrom This reversing roller
22
can also comprise a continuous cylinder or several discrete rollers disposed on a common shaft. The reversing roller
22
can be reversed under control and is drivable in both directions of rotation. A pressure roller
24
cooperates with the reversing roller
22
which is supported freely rotatably on the free end of a roller lever
26
. The roller lever
26
is pivotably supported at
27
in such a way that the pressure roller
24
can be pivoted between a position shown in
FIG. 1
away from the reversing roller
22
and a position shown in
FIG. 2
resting on the reversing roller
22
.
Adjacent to the roller lever
26
is connected a pivot flap
28
which extends substantially over the width of the document
10
and extends generally from a pivot bearing
29
in the region of the front-end roller
14
to the pressure roller
24
.
Adjacent to the output roller
18
is a guidance flap
30
, which is articulated pivotably about an axle
32
. The free end of the guidance flap
30
extends beyond the reversing roller
22
and comprises cutouts
33
in which the reversing roller
22
can extend through. The guidance flap
30
is pivotable between an upper position as depicted in
FIG. 1 and a
lower position as depicted in FIG.
2
. In the upper position (
FIG. 1
) the plane of the guidance flap
30
is outside of the circumference of the reversing roller
22
. In the lower pivot position (
FIG. 2
) the plane of the guidance flap
30
intersects the reversing roller
22
such that the latter extends through the cutouts
33
of the guidance flap
30
. In such a manner, the reversing roller
22
projects with its circumference above the top side of the guidance flap
30
. The roller lever
26
is preferably coupled with the pivot flap
28
and the guidance flap
30
such that these are pivoted jointly between the positions shown in
FIGS. 1 and 2
.
The operation of the shunt will now be discussed. A document
10
arrives from a printer in the direction of the arrow
11
as shown in FIG.
1
. The arriving document
10
is detected at its front edge by the sensor
12
whereupon the driving of the front-end roller
14
is started. The front-end roller
14
is driven in the drawing-in direction i.e. in the drawing in the counterclockwise rotation. The pressure roller
24
is raised by means of the roller lever
26
from the reversing roller
22
and pivoted upward. The guidance flap
30
is also pivoted upward such that it is located above the outer circumference of reversing roller
22
. The front edge of the incoming document
10
is taken hold of between the front-end roller
14
and its pressure roller
16
. As the document
10
is drawn in, the document
10
actuates a second sensor
34
which is disposed in the region of the entry gap of the front-end roller
14
. A signal from the second sensor
34
initiates the driving of the output roller
18
, in the counterclockwise direction as shown in FIG.
3
.
As soon as the trailing rear edge of document
10
has passed the first sensor
12
, a signal from sensor
12
causes both the roller lever
26
(with the pressure roller
24
) and the guidance flap
30
to be lowered from the position depicted in
FIG. 1
into the position as shown in FIG.
2
. The driving of the reversing roller
22
is set such that the reversing roller
22
rotates in the clockwise direction and has the same circumferential speed V
1
as the front-end roller
14
. The rpm of the front-end roller
14
can simultaneously be increased and thus the conveyance of the document
10
can be accelerated. With the lowering of the pressure roller
24
the leading front edge of document
10
can be clamped between the pressure roller
24
and the reversing roller
22
, and together with the front-end roller
14
, can convey the document farther to the right, as shown in the figures.
As soon as the trailing rear edge of document
10
has passed the second sensor
34
and is thus released from the front-end roller
14
, the signal of sensor
34
causes the pivot flap
28
to be pivoted downward. In such a manner, the rear region of the document
10
is pushed by the pivot flap
28
downwardly onto the guidance flap
30
, as is shown in FIG.
2
. The signal from the second sensor
34
also reverses the direction of rotation of the reversing roller
22
so that the reversing roller
22
now rotates, in the representation of the drawing, in the counterclockwise direction and thereby conveys the document
10
to the left, as is shown in
FIG. 2
by the arrow
13
. The rear edge of document
10
arrives thereby at the output roller
18
and is taken hold of by this output roller
18
and its pressure roller
20
and conveyed further. The driving of the reversing roller
22
takes place at the same circumferential speed V
2
as the driving of output roller
18
.
Now roller lever
26
, the connected pivot flap
28
, and the guidance flap
30
are pivoted upwardly as is shown in FIG.
3
. Thereby the shunt is ready to accept the succeeding next document
10
′.
As is shown in
FIG. 3
the succeeding next document
10
′ can already be accepted and drawn in through the front-end roller
14
while the preceding document
10
is still being conveyed and output by the output roller
18
. Indeed, with the guidance flap
30
raised beyond the circumference of the reversing roller
22
, which is now driven again in the clockwise direction, does not hinder the drawing-off of document
10
by the output roller
18
. The succeeding next document
10
′ can thus be drawn into the reversing roller
22
overlapping the preceding document even though the preceding document
10
has not been output completely via the output roller
18
. Further, the document can be drawn with the higher speed V
2
from the reversing roller
22
, as is shown in FIG.
4
. Thereby a higher document sequential throughout can be attained. In such a manner the shunt does not delay the usual conveyance documents output from an office machine.
While particular embodiments of the present invention have been disclosed, it is to be understood that various different modifications are possible and are contemplated within the true spirit and scope of the appended claims. There is no intention, therefore, of limitations to the exact abstract or disclosure herein presented.
Claims
- 1. A shunt for reversing the conveyance direction of a document, comprising:a front-end roller pair for accepting the incoming document at its front edge; an output roller pair disposed axis-parallel and offset with respect to the front-end roller pair, the output roller pair for outputting the document with its rear edge leading in the opposite direction; a reversing roller disposed axis-parallel on the side opposing the incoming side of the front-end roller pair and of the output roller pair; and a guidance flap for raising the document from a circumference of the reversing roller when the rear edge of document has been taken hold of by the output roller pair and the document is being conveyed by the output roller pair, wherein the reversing roller takes hold of the document conveyed by the front end roller pair and transports the document further until the rear edge of document has left the front-end roller pair and subsequently reverses direction of rotation of the reversing roller to transport the rear edge of document to the output roller pair.
- 2. The shunt according to claim 1, wherein the reversing roller is associated with a pressure roller, the pressure roller being pivotable toward the reversing roller and away from the reversing roller, and wherein the pressure roller is pivoted against the reversing roller at least during the time interval before the rear edge of the document has left the front-end roller pair until the rear edge of document has been taken hold of by the output roller pair.
- 3. The shunt according to claim 2 wherein the guidance flap pivots, and the pivot motion of the guidance flap is coupled with a pivot motion of the pressure roller.
- 4. The shunt according to claim 1, further including a pivot plate for urging the rear edge of document toward entry to the output roller pair after the document leaves the front-end roller pair.
- 5. The shunt according to claim 4 wherein the pivot plate pivots, and the pivot motion of the pivot plate is coupled with a pivot motion of a pressure roller.
- 6. The shunt according to claim 1, wherein a circumferential speed of the output roller pair is greater than the circumferential speed of the front-end roller pair.
- 7. A shunt for reversing the conveyance direction of a document, comprising:a front-end roller pair for accepting the incoming document at its front edge; an output roller pair disposed axis-parallel and offset with respect to the front-end roller pair, the output roller pair for outputting the document with its rear edge leading in the opposite direction; a reversing roller disposed axis-parallel on the side opposing the incoming side of the front-end roller pair and of the output roller pair; and a pivot plate for urging the rear edge of document toward entry to the output roller pair after the document leaves the front-end roller pair, wherein the reversing roller takes hold of the document conveyed by the front end roller pair and transports the document further until the rear edge of document has left the front-end roller pair and subsequently reverses direction of rotation of the reversing roller to transport the rear edge of document to the output roller pair, and wherein the pivot plate pivots, and the pivot motion of the pivot plate is coupled with a pivot motion of a pressure roller.
- 8. The shunt according to claim 7, wherein the reversing roller is associated with the pressure roller, the pressure roller being pivotable toward the reversing roller and away from the reversing roller, and wherein the pressure roller is pivoted against the reversing roller at least during the time interval before the rear edge of the document has left the front-end roller pair until the rear edge of document has been taken hold of by the output roller pair.
- 9. The shunt according to claim 7, further including a guidance flap for raising the document from a circumference of the reversing roller when the rear edge of document has been taken hold of by the output roller pair and the document is being conveyed by the output roller pair.
- 10. The shunt according-to claim 9, wherein the guidance flap pivots, and the pivot motion of the guidance flap is coupled with a pivot motion of the pressure roller.
- 11. The shunt according to claim 7, wherein a circumferential speed of the output roller pair is greater than the circumferential speed of the front-end roller pair.
Priority Claims (1)
Number |
Date |
Country |
Kind |
198 44 230 |
Sep 1998 |
DE |
|
US Referenced Citations (7)
Foreign Referenced Citations (3)
Number |
Date |
Country |
011 85 994 |
Jan 1965 |
DE |
32 17 115 A1 |
Nov 1983 |
DE |
195 06 181 A1 |
Feb 1995 |
DE |