METHOD OF OPERATING A DOCUMENT FEEDING MECHANISM TO REDUCE CHANCE OF A DOCUMENT JAM CONDITION AND AN APPARATUS THEREFOR

Abstract

A method is provided of operating a document feeding mechanism having a document transport path which passes through an extended nip defined between an advance belt disposed on one side of a document transport path and a retard belt disposed on an opposite side of the document transport path. The method comprises controlling operation of the advance belt to pick sheets from a document stack and to feed picked sheets one-by-one through the extended nip from an upstream end of the document transport path to a downstream end of the document transport path, and controlling operation of the retard belt to hold back other sheets of the document stack from being fed through the extended nip as one sheet is being picked from the document stack and fed through the extended nip from the upstream end of the document transport path to the downstream end of the document transport path and thereby to reduce chance of a document jam condition.

Description

BACKGROUND

The present invention relates to document feeding along a document transport path, and is particularly directed to a method of operating a document feeding mechanism to reduce chance of a document jam condition and an apparatus therefor.

A known type of document feeding mechanism 10 is illustrated in FIG. 1. The mechanism 10 includes an advance drive roller 12 which lies on one side of a document transport path 14. The advance drive roller 12 is driven to rotate about its longitudinal central axis to drive an advance belt 16. The advance belt 16 picks sheets of documents from a document stack 18, and feeds the sheets one-by-one along the document transport path 14. Typically, the advance belt 16 has a high coefficient of friction to pull sheets off the top of the document stack 18.

The mechanism 10 further includes a retard drive roller 20 which lies on the opposite side of the document transport path 14 and faces the advance drive roller 12 to form a nip 22 therebetween. The retard drive roller 20 is driven to rotate about its longitudinal central axis so that it is counter rotating relative to the advance drive roller 12 in the nip 22. The counter rotation of the retard drive roller 20 acts to hold back other sheets when a single sheet is being fed through the nip 22 along the document transport path 14.

A drawback in using the known document feeding mechanism 10 of FIG. 1 is that a very limp or soft sheet 30 (such as a used banknote for example) may fold over at the separation point, such as shown FIG. 2, when the sheet is being separated away from the document stack 18. This folding over of the limp sheet 30 may cause a document jam condition to occur along the document transport path 14. If the folding over of the limp sheet 30 rolls along the sheet, such as shown in FIG. 3, the sheet may even flip over. It would be desirable to provide a document feeding mechanism in which a very limp or soft sheet can be fed through the nip 22 along the document transport path 14 with reduced chance of the sheet either flipping over or causing a document jam condition.

SUMMARY

In accordance with one embodiment of the present invention, a method is provided of operating a document feeding mechanism having a document transport path which passes through an extended nip defined between an advance belt disposed on one side of a document transport path and a retard belt disposed on an opposite side of the document transport path. The method comprises controlling operation of the advance belt to pick sheets from a document stack and to feed picked sheets one-by-one through the extended nip from an upstream end of the document transport path to a downstream end of the document transport path, and controlling operation of the retard belt to hold back other sheets of the document stack from being fed through the extended nip as one sheet is being picked from the document stack and fed through the extended nip from the upstream end of the document transport path to the downstream end of the document transport path and thereby to reduce chance of a document jam condition.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIGS. 1-3 is a schematic view of a known document feeding mechanism;

FIG. 4 is a schematic view of a document feeding mechanism constructed in accordance with one embodiment of the present invention;

FIGS. 5 and 6 are views similar to FIG. 4 and showing parts in different positions.

DETAILED DESCRIPTION

The present invention is directed to a method of operating a document feeding mechanism to reduce chance of a document jam condition and an apparatus therefor. The specific use and construction of the document feeding mechanism may vary. By way of example, a document feeding mechanism 50 constructed in accordance with one embodiment of the present invention is illustrated in FIG. 4.

The document feeding mechanism 50 has an upstream end 52, a downstream end 54, and a document transport path 56 extending between the upstream end and the downstream end. The document feeding mechanism 50 includes an advance drive roller 60 which is adjacent to one side of the document transport path 56. The advance drive roller 60 has a longitudinal central axis and an outer circumferential surface 62. The advance drive roller 60 is rotatably mounted on a first shaft 64 for rotation about its longitudinal central axis.

The document feeding mechanism 50 further includes a retard drive roller 70 which is adjacent to an opposite side of the document transport path 56 and faces the advance drive roller 60. The retard drive roller 70 has a longitudinal central axis and an outer circumferential surface 72. The retard drive roller 70 is rotatably mounted on a second shaft 74 for rotation about its longitudinal central axis. A nip 58 is defined between the outer circumferential surface 62 of the advance drive roller 60 and the outer circumferential surface 72 of the retard drive roller 70.

The document feeding mechanism 50 also includes a first endless continuous belt 80 which is drivingly coupled between the advance drive roller 60 and a first idler roller 66, and a second endless continuous belt 90 which is drivingly coupled between the retard drive roller 70 and a second idler roller 76. The first belt 80 is referred to herein as the “advance belt”, and the second belt 90 is referred to herein as the “retard belt”. The first belt 80 has an outer circumferential surface 82, and the second belt 90 has an outer circumferential surface 92. An extended nip 88 is defined between the outer circumferential surface 82 of the first belt 80 and the outer circumferential surface 92 of the second belt 90.

As shown in FIG. 4, the extended nip 88 is disposed along the document transport path 56 approximately between the longitudinal central axis of the second idler roller 76 and the longitudinal central axis of the retard drive roller 70. The extended nip 88 overlies the relatively smaller nip 58, and is disposed over a linear portion of the document transport path 56. Accordingly, the document transport path 56 passes through both the nip 58 and the extended nip 88.

A controller 100 provides a control signal via line 102 to the advance drive roller 60 to control operation of the advance drive roller and thereby to control operation of the advance belt 80. The controller 100 also provides a control signal via line 104 to the retard drive roller 70 to control operation of the retard drive roller and thereby to control operation of the retard belt 90.

During operation of the document feeding mechanism 50 (as shown in FIG. 4), the controller 100 controls the advance drive roller 60 to rotate about its longitudinal central axis in the counter-clockwise direction (as viewed looking at FIG. 4). The controller 100 controls the retard drive roller 60 to rotate about its longitudinal central axis also in the counter-clockwise direction. As the advance drive roller 60 and the retard drive roller 70 both rotate in the counter-clockwise direction, the advance and retard belts 80, 90 co-operate to pick and feed a single document 110 from a document stack 108 through the extended nip 88 along the document transport path 56.

More specifically, due to frictional engagement of the outer circumferential surface 82 of the advance belt 80 with the single document 110, the leading edge 112 of the document 110 is transported from the position shown FIG. 4 to the position shown in FIG. 5. In FIG. 5, the leading edge 112 of the document 110 is shown positioned between the outer circumferential surface 82 of the advance belt 80 and the outer circumferential surface 92 of the retard belt 90. As the document 110 continues to move downstream along the document transport path 56 from the position shown in FIG. 5 to the position shown in FIG. 6, the leading edge 112 of the document 110 exits the extended nip 88. The document 110 continues to move downstream along the document transport path 56 for further handling and processing at the downstream end of the document transport path.

It should be apparent that the operation of the document feeding mechanism 50 described hereinabove enables the document 110 to be fed through the relatively larger extended nip 88 which is defined between the advance and retard belts 80, 90 instead of being fed through just the relatively smaller nip 88 which is defined between the advance drive roller 60 and the retard drive roller 70. By feeding the document 110 through the linearly-extending nip 88, the tendency of the leading edge 112 of the document 110 to fold over, and thereby possibly causing a document jam condition, is reduced. The tendency of such a fold to roll along the length of the document 110, and thereby possibly causing the document to flip over, is also reduced.

The particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention. From the above description, those skilled in the art to which the present invention relates will perceive improvements, changes and modifications. Numerous substitutions and modifications can be undertaken without departing from the true spirit and scope of the invention. Such improvements, changes and modifications within the skill of the art to which the present invention relates are intended to be covered by the appended claims.

Claims

1. A method of operating a document feeding mechanism having a document transport path which passes through an extended nip defined between an advance belt disposed on one side of a document transport path and a retard belt disposed on an opposite side of the document transport path, the method comprising: controlling operation of the advance belt to pick sheets from a document stack and to feed picked sheets one-by-one through the extended nip from an upstream end of the document transport path to a downstream end of the document transport path; andcontrolling operation of the retard belt to (i) hold back other sheets of the document stack from being fed through the extended nip as one sheet is being picked from the document stack and fed through the extended nip from the upstream end of the document transport path to the downstream end of the document transport path, and (ii) reduce tendency of a leading edge of the one sheet to fold over and roll along its length as the leading edge is being fed into the extended nip and thereby to reduce chance of a document jam condition.

2. A method according to claim 1, wherein the extended nip is disposed along a linear portion of the document transport path.

3. A method according to claim 2, wherein the extended nip overlies a relatively smaller nip which is disposed between an advance drive roller driving the advance belt and a retard drive roller driving the retard belt.

4-9. (canceled)

10. A method of operating a banknote feeding mechanism having a banknote transport path which passes through an extended nip defined between an advance belt disposed on one side of the banknote transport path and a retard belt disposed on an opposite side of the banknote transport path, the method comprising: locating the retard belt relative to a stack of used banknotes to enable the retard belt to reduce tendency of a leading edge of a used banknote which has been picked from the stack to fold over and roll along its length as the leading edge is being fed into the extended nip and thereby to reduce chance of a banknote jam condition along the banknote transport path.

11. A method according to claim 10, wherein the extended nip is disposed along a linear portion of the banknote transport path.

12. A method according to claim 11, wherein the extended nip overlies a relatively smaller nip which is disposed between an advance drive roller driving the advance belt and a retard drive roller driving the retard belt.

13. A method of operating a banknote feeding mechanism having a banknote transport path which passes through an extended nip defined between an advance belt disposed on one side of the banknote transport path and a retard belt disposed on an opposite side of the banknote transport path, the method comprising: locating the advance belt relative to a stack of limp, used banknotes to pick limp, used banknotes from the stack and to feed limp, used banknotes one-by-one through the extended nip from an upstream end of the banknote transport path to a downstream end of the banknote transport path; andlocating the retard belt relative to the advance belt and the stack of limp, used banknotes to enable the retard belt to reduce tendency of a leading edge of a limp, used banknote which has been picked from the stack to fold over and roll along its length as the leading edge is being fed into the extended nip and thereby to reduce chance of a banknote jam condition along the banknote transport path.

14. A method according to claim 13, wherein the extended nip is disposed along a linear portion of the banknote transport path.

15. A method according to claim 14, wherein the extended nip overlies a relatively smaller nip which is disposed between an advance drive roller driving the advance belt and a retard drive roller driving the retard belt.