Document feed apparatus

Abstract

A document, which is fed by a single belt, is prevented from wrapping around the belt as it exits from the belt by a plurality of rollers, which are rotated in the same direction as the belt but with a greater peripheral speed. Each of the rollers, which are axially spaced from each other, cooperates with a resiliently biased element to form a nip along the path of the document beyond the exit end of the belt. At their point of engagement with the belt, the peripheral direction of the rollers is opposite to that of the belt to prevent the paper from moving with the belt past this point. Fingers are disposed between the rollers to prevent the document from wrapping around the rollers as it is fed by the rollers. Resiliently biased rollers engage spaced portions of the single belt across its width to provide a driving force from the belt to the document while insuring that the leading edge of the document stops at gate fingers, which have the resiliently biased rollers therebetween and determine the position at which the document is held for reproduction or copying purposes in a photocopy machine prior to being advanced from the copying position by the belt.

Description

In photocopy machines, it is desired to be able to produce many copies of the same ducument or different documents at a fast rate. As a result, each document, which is to be reproduced by the photocopy machine, should be fed to a reproducing or copying position along a predetermined path as quickly as possible and then removed therefrom along a predetermined path to a receiving area as quickly as possible after completion of copying of the document.

One means of advancing the document to this copying position and then removing the document form this copying position has been to use an endless belt arrangement wherein the belt drives the document to the copying position on a platen, and then removes the document form the copying position upon completion of copying of the document. Furthermore, the belt is capable of starting the feed of another new document to the copying position as the copied document leaves the platen.

When the document leaves the platen, it tends to want to follow the path of the endless belt in some instances. Thus, since the belt is mounted on support and drive rollers at its ends, the document would tend to follow the travel of the belt so as to wrap around the belt at the exit end of the belt.

When a single belt is used for feeding the document from the platen, any arrangement for preventing the document from tending to wrap around the single belt at the exit end of the belt must be in engagement with the belt because the document may be thin enough to pass between any preventing means spaced even slightly from the belt. One reason for this capability of the thin document passing between spaced preventing means is that rubbing of the belt against the document and the document against the platen produces electrostatic charges tending to cause the thin document to adhere to the belt in some instances.

If a fixed document preventing means engages the belt to prevent the document from wrapping around the belt, the feed speed of the trailing portion of the document being urged by the belt would cause the document to wad up against the fixed document preventing means. Since this would prevent feed of the document, a fixed document preventing means, which engages the single belt, has not previously been capable of preventing the document from wrapping around the belt.

Even if a fixed document preventing means could be arranged in some manner to not cause wadding up of the document, it would have the further problem of possibly scraping the belt because of the fixed document preventing means engaging the belt. As a result, dirt could collect in the scrapes of the belt and produce streaks on copies made from the document disposed at the reproduction or copying position. This would occur when the document is rather thin or when the document does not extend for the width of the belt.

One previously available belt means for advancing a document to and from a platen while preventing the document from wrapping around the exit end of the belt means has used a plurality of separate belts, which are spaced from each other in the direction of the width of the document being fed. These have enabled fixed document engaging means to be disposed between the belts to prevent the document from wrapping around the belts.

However, the use of a plurality of belts can cause stripes, which are produced by the edges of the belts, to appear on the copy produced from the document when the document is relatively thin or if the document is not as wide as the belts. Thus, a striped effect may be produced on the copies by the separate belts.

The present invention satisfactorily solves the foregoing problem by providing means to prevent the document from wrapping around a belt, which is advancing the document, while still not having any striped effect on the copies. The present invention accomplishes this by utilizing a single belt so that the striped effect produced by the plurality of separate belts is eliminated. At the same time, the present invention employs rotating means in engagement with the portion of the belt wrapped around the exit end roller or rollers of the belt so that there is no wadding up of the document or scraping of the belt by any fixed preventing means. Thus, the rotating means, which preferably comprises a plurality of separate rollers spaced axially from each other, not only can engage the belt without damaging it but also prevent the document from wrapping around the belt.

The rollers are disposed so that the surface of each of the rollers engages the belt adjacent its exit end roller or rollers. With the rollers rotating in the same direction as the portion of the belt engaging the document, the peripheral or tangential direction of each of the rollers at its engagement with the belt is opposite to that in which the belt is moving. Thus, the rollers cause the leading edge of the document to return to the predetermined path if the document should follow the travel of the belt as the belt is wrapped around the exit end roller or rollers. The rollers are preferably rotated at a greater peripheral speed than the belt to insure that the rollers dominate the direction in which the leading edge of the document is moved.

Another problem with a single belt for feeding a document has been for the belt to positively engage the document to advance it and to prevent the document from passing beyond gate fingers, which engage the leading edge of the document for retention at the reproduction or copying position. The previously available plurality of separate belts has effectively solved this problem through having the gate fingers disposed between the belts. However, the problem of the striped background effect on copies exists when using the plurality of separate belts as previously mentioned.

The present invention satisfactorily solves the foregoing problems through eliminating the striped background effect on copies produced by the plurality of separate belts by using a single belt while still having the single belt advance the document to the reproduction or copying position and against the gate fingers without advancing the document beyond the gate fingers. The present invention employs a plurality of resiliently biased rollers disposed across the width of the single belt and within the track of the belt. These rollers create bubbles in the belt at their engagements with the belt to hold the document against the platen so that the leading edge of the document abuts against the raised gate fingers whereby the travel of the document is stopped. The engagement of the resiliently biased rollers with the belt also created a high driving force when the document is to be removed from the platen after the gate fingers, which have one of the resiliently biased rollers between each adjacent pair of the gate fingers, have moved out of their blocking positions and the belt activated.

An object of this invention is to provide a document feed apparatus that insures that the document continues along a predetermined path after leaving its belt advancing means.

Another object of this invention is to provide an arrangement for a belt feed for a document to prevent the document from wrapping around a belt as the endless belt changes direction at the completion of feed of the document by the belt.

A further object of this invention is to provide a single belt for feeding a document.

The foregoing and other objects, features, and advantages of the invention will be more apparent from the following more particular description of a preferred emobdiment of the invention as illustrated in the accompanying drawings. In the drawings:

FIG. 1 is a sectional view, partly in elevation, of the document feed apparatus of the present invention being used with a photocopy machine and taken along line 1--1 of FIG. 2.

FIG. 2 is a top plan view, partly in section, of the document feeding apparatus of FIG. 1.

FIG. 3 is a fragmentary sectional view, partly in elevation, of a portion of the document feed apparatus of FIG. 1.

FIG. 4 is an end elevational view, partly in section, of the feed document apparatus shown in FIG. 3.

Referring to the drawings and particularly FIG. 1, there is shown a platen 10 of a photocopy machine 11 with which the document feed apparatus of the present invention is employed. Documents 12 are fed from a guide 14 of the photocopy machine 11 to the surface of the platen 10 whenever pivotally mounted gate fingers 15 are removed from their document blocking or preventing position by the logic of the photocopy machine. The guide 14 has an extension 16 to direct the document toward the surface of the platen 10.

The document feed apparatus of the present invention includes a single endless belt 17, which is supported by rollers 18 and 19 at the ends of the belt 17 at which the direction of travel of the belt 17 is reversed. The belt 17 is tangent to the lower portions of the rollers 18 and 19 slightly above the top surface of the platen 10.

The belt 17 is formed of any suitable elastic material having a desired coefficient of friction relative to the document 12 and the platen 10. The material of the belt 17 also should have such triboelectric characteristics as to prevent the document 12 from adhering too strongly to the belt 17. One suitable example of the material of the belt 17 is neoprene.

The rollers 18 and 19 are rotatably mounted in a torque box 20, which is supported in a casing 21 by being secured to downwardly extending projections 21' of the casing 21. The casing 21 is pivotally mounted on the photocopy machine 11 to move the document feed apparatus away from the platen 10 when desired.

The belt 17 is driven from a motor 22 (see FIG. 2), which is supported by the casing 21. A shaft extension 23 of the roller 19 has a spring clutched pulley 24, which is continuously driven through a timing belt 25 from the motor 22, supported thereon. The timing belt 25 passes around a pulley 26 on a shaft 27 of the motor 22. Accordingly, whenever the pulley 24 is connected to the shaft extension 23 by the spring clutch through a magnet being energized to cause a plastic shoe on its arm to move a spring of the spring clutch against the shaft extension 23, the roller 19 is rotated clockwise (as viewed in FIG. 1) to cause the lower portion of the belt 17 to move to the left and the upper portion to move to the right so that the belt 17 can advance one of the documents 12 along the platen 10.

As the document 12 moves down along the quide 14, an entry spring 28 urges the document 12 against the lower portion of the belt 17 adjacent the roller 18 so that the document 12 is moved with a high driving force by the belt 17 onto the platen 10. Because of the sag in the belt 17, the document 12 is in a low force area when disposed beneath the belt 17 and on the top surface of the platen 10 although there is some drive.

As the document 12 is advanced along the platen 10 by the belt 17, travel of the document 12 is stopped by a plurality of gate fingers 29, which are moved into a blocking or preventing position by a spring 30 (see FIG. 4) when a solenoid 31 is inactivated. Any other suitable actuating means can be employed.

To insure that the document 12 engages the gate fingers 29, back-up rollers are supported within the track of the belt 17 between each adjacent pair of the gate fingers 29. Each of the back-up rollers 32 is rotatably supported in a carrier 33 by the roller 32 being disposed between a pair of bifurcated arms 34 of the carrier 33.

The carrier 33 is pivotally mounted on a support 35, which is fixed to a bottom plate 35' of the torque box 20. The support 35 has an upright extension 36 at its end remote from the pivotal connection of the carrier 33 to the support 35 and to which one end of a spring 37 is secured. The other end of the spring 37 is secured to an upright extension 38 of the carrier 33. Accordingly, the spring 37 continuously urges the carrier 33 counterclockwise (as viewed in FIG. 3) about the pivotal connection between the carrier 33 and the support 35 so that the back-up roller 32 is continuously urged into engagement with the inside surface of the belt 17 adjacent the gate fingers 29.

As a result of the downward force exerted by the back-up rollers 32, bubbles 39 (see FIG. 4) are formed in the belt 17 between each pair of the gate fingers 29. Each of the bubbles 39 is a protrusion of the belt 17 so that the belt 17 pushes the document downwardly against the platen 10. As a result, the leading edge of the document 12 engages the gate fingers 29 to stop the document 12 on the platen 10 at the reproduction or copying position. Furthermore, the back-up rollers 32 provide a positive driving force on the document 12 from the belt 17 at this point when the gate fingers 29 are removed from their blocking or preventing position to allow the document 12 to be fed from the platen 10.

When the gate fingers 29 are pulled downwardly when the solenoid 31 is activated, activation of the roller 19 thereafter by the pulley 24 being connected to the shaft extension 23 of the roller 19 through the spring clutch being activated causes the document 12 to be fed from the platen 10. To prevent the document 12 from following the travel or path of the belt 17 as the belt 17 wraps around the drive roller 19 to reverse its direction of travel in its upper portion, a plurality of rollers 41 (see FIGS. 1 and 2) is supported in spaced relation along a shaft 42.

The rollers 41, which are preferably formed of a light weight plastic having a low spring rate such as polyurethane foam, for example, are driven at the same time as the roller 19 is driven and in the same direction. The shaft 42 for the rollers 41 has a pulley 43 mounted thereon for dirving engagement with a timing belt 44, which passes around a pulley 45 on the shaft extension 23 of the roller 19.

The pulley 43 is of a smaller diameter than the pulley 45 so that the peripheral speed of each of the rollers 41 is greater than the peripheral speed of the roller 19 or the belt 17. This aids in advancing the document 12 away from the belt 17 and between the rollers 41 and a resiliently biased plate 46.

The plate 46 is continuously urged by a spring 47 into engagement with the roller 41 to form a nip therebetween. The plate 46 is disposed to direct the document 12 toward a storage bin 48 of the photocopy machine 11.

Because the rollers 41 are engaging the belt 17, the leading edge of the document 12 cannot advance between the belt 17 and the rollers 41. Furthermore, with the peripheral speed of the speed of the rollers 41 being greater than the roller 19, the document 12 is prevented from adhering to the belt 17. At the point of engagement between each of the rollers 41 and the belt 17, the peripheral or tangential directions of the roller 19 and each of the rollers 41 are opposite.

As the leading edge of the document 12 passes through the nip formed between the rollers 41 and the plate 46, a switch actuator 49, which is pivotally mounted on the casing 21 through a rod 48', is moved clockwise (as viewed in FIG. 1) to have a portion 49' engage an arm 50 of a switch 51 to cause closing of the switch 51. The closing of the switch 51 supplies a signal to the logic for the photocopy machine 11. This results in the solenoid 31 (see FIG. 4) being inactivated so that the gate fingers 29 are returned to their blocking position by the spring 30. Then, the gate fingers 15, (see FIG. 1) are pivotally moved out of their blocking position if there is another of the documents 12 in the guide 14 for transport to the platen 10.

Thus, the feed of the document 12 from the guide 14 starts before the document 12 on the platen 10 is completely removed from the platen 10. If there is no document 12 in the guide 14 and in engagement with the gate fingers 15, then when the trailing edge of the document 12 passes beyond the switch acutator 49, the switch 51 causes the pulley 24 of the shaft extension 23 of the roller 19 to be disconnected from the shaft extension 23 so that the roller 19 and the rollers 41 are no longer driven whereby the belt 17 stops.

As the document 12 exits through the nip between the rollers 41 and the plate 46, the document 12 has a tendency to wrap around the rollers under conditions such as the document 12 being extremely curled or wrinkled or the document 12 being electrostatically charged, for example. To prevent this, fingers 52 on a plate 53, which is carried by the casing 21, are interposed between the rollers 41.

Accordingly, the document 12 can be fed to the copying or reproduction position on the platen 10 by driving the roller 19 through connecting the shaft extension 23 of the roller 19 to the pulley 24 mounted thereon. With the gate fingers 15 pivotally mounted out of the way, the document 12 can move between the entry spring 28 and the idler roller 18 so that there is a driving force on the document 12 to cause it to be advanced by the belt 17 along the platen 10 until it engages the gate fingers 29, which are raised after the leading edge of the document 12 previously on the platen 10 has been advanced past the gate fingers 29. As the leading edge of the new document 12 approaches the gate fingers 29, the back-up rollers 32 insure that the leading edge of the document 12 engages the gate fingers 29 to stop the document 12 at the reproduction or copying position on the platen 10.

Upon completion of copying of the document 12 on the platen 10, the logic of the photocopy machine 11 causes energization of the solenoid 31 to lower the gate fingers 29. Then, after a predetermined time delay, the roller 19 is driven to advance the document 12 from the platen 10 to the nip between the rollers 41 and the resiliently biased plate 46. The back-up rollers 32 exert a driving force through the belt 17 on the document 12 as the belt 17 is driven from the roller 19.

As the leading edge of the document 12 passes the nip between the resiliently biased plate 46 and the rollers 41, the switch actuator 49 is moved by the document 12 to cause closing of the switch 51. As a result, the logic of the photocopy machine 11 causes deenergization of the solenoid 31 so that the spring 30 moves the gate fingers 29 upwardly. Then, the gate fingers 15 are pivoted downwardly if another of the documents 12 is in the guide 14. If one of the documents 12 is not in the guide 14, the switch 51, which is actuated by the trailing edge of the document 12 leaving the platen 10 as it passes through the switch actuator 49, stops the belt 17 and the rollers 41. If another of the documents 12 is entering onto the platen 10 from the guide 14, a switch (not shown) on the guide 14 stops the belt 17 and the rollers 41 through supplying a signal to the logic of the photocopy mahcine 11.

While the present invention has shown and described the rollers 41 as having a greater peripheral speed than the roller 19 and the belt 17, it is only necessary that they have at least the same peripheral speed as the roller 19 although it is preferred that they have a greater speed than the roller 19 and the belt 17. While the pulley 43 on the shaft 42 has been shown as being smaller than the pulley 45 on the shaft extension 23 to obtain a greater peripheral speed for the rollers 41 than the roller 19, it should be understood that the rollers 41 may have a larger diameter than the roller 19 and the diameters of the pulleys 43 and 45 could be the same to produce the different peripheral speeds.

While the rollers 41 have been shown as being disposed with their axis of rotation almost in the same horizontal plane as the axis of rotation of the roller 19, it should be understood that the position of the rollers 41 is dependent upon the predetermined path in which it is desired to feed the document 12 from the platen 10. That is, if it is desired to raise the predetermined path, the rollers 41 would be moved upwardly from the position of FIG. 1. Similarly, the rollers 41 could be lowered with respect to the roller 19 if it were desired to have a lower predetermined path for the document 12 as it leaves the platen 10. It is only necessary that the rollers 41 engage the belt 17 at a portion of the belt 17 wrapped around the roller 19.

Instead of utilizing the rollers 41, any rotating arrangement to prevent the sheet 12 from following the path of the belt 17 could be employed. For example, a single roller or a plurality of separate belts could be used instead of the rollers.

While the rollers 41 have particular utility in preventing the document 12 from wrapping around the belt 17 at the exit end of the belt 17, it should be understood that the rollers 41 could be utilized with a belt drive arrangement having a plurality of separate belts rather than the single belt 17 to cause an increased driving force on the document 12.

It should be understood that each of the rollers 18 and 19 has a flat central portion and tapering portions on each side thereof to insure that the belt 17 tracks properly. Furthermore, the position of the idler roller 18 is adjustable with respect to the drive roller 19 to slightly alter the distance therebetween to control the position of the tracking of the belt 17 on the platen 10.

An advantage of this invention is that it insures that a document, which is fed by a belt, exits in a predetermined path. Another advantage of this invention is that it enables a single drive belt to be used for feeding a document.

While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

Claims

What is claimed is:

1. A document feeding apparatus including:

belt means for feeding a document along a predetermined path;

rotating means disposed adjacent the axit end of said belt means and cooperating with said belt means to cause the document to continue to follow the predetermined path when said belt means ends, said rotating means rotating in the same rotary direction as the engaging portion of said belt means to feed the document along the predetermined path;

said rotating means having a peripheral speed at least equal to the peripheral speed of said belt means;

and means engaging said rotating means to form a nip therebetween along the predetermined path beyond the exit end of said belt means to enable said rotating means to create a driving force on the document to advance the document from said belt means along the predetermined path.

2. The apparatus according to claim 1 in which:

said rotating means comprises roller means engaging said belt means adjacent its exit end;

and said roller means and said belt means having opposite peripheral directions at their point of engagement.

3. The apparatus according to claim 2 in which said roller means has a greater peripheral speed than the peripheral speed of said belt means.

4. The apparatus according to claim 3 in which said roller means comprises a plurality of rollers having the same axis of rotation and axially spaced from each other.

5. The apparatus according to claim 4 including means extending between said rollers to prevent the document from wrapping around said rollers after passing through the nip.

6. The apparatus according to claim 2 in which said roller means comprises a plurality of rollers having the same axis of rotation and axially spaced from each other.

7. The apparatus according to claim 6 including means extending between said rollers to prevent the document from wrapping around said rollers after passing through the nip.

8. The apparatus according to claim 7 in which said engaging means comprises means resiliently urged against said rollers.

9. The apparatus according to claim 8 in which: said belt means comprises:

a single belt;

means disposed beneath said single belt to support the document as it is moved by said single belt in a direction along the length of said belt;

means acting on spaced portions across the width of said belt to urge each of the spaced portions of said belt against the document on said disposed means as it moves along the predetermined path;

and gate means disposed across the width of said belt between said acting means to stop the feed of each of the documents by said belt at selected times at a predetermined position, said acting means being spaced relative to said gate means in the direction in which the document is moved so as to cause each of the documents to the engaged by said gate means at the selected times.

10. The apparatus according to claim 1 in which said rotating means has a greater peripheral speed than the peripheral speed of said belt means.

11. A document feeding apparatus including:

a single belt;

means disposed beneath said belt to support the document as it is moved by said belt in a direction along the length of said belt;

means to support said belt at each of its ends to cause movement of said belt in an endless track in directions along its length;

means acting on spaced portions of said belt across its width to urge the spaced portions of said belt against the document on said document support means to feed the document;

and gate means disposed across the width of said belt between said acting means to stop the feed of each of the documents by said belt at selected times at a predetermined position, said acting means being spaced relative to said gate means in the direction in which the document is moved so as to cause each of the documents to be engaged by said gate means at the selected times.

12. The apparatus according to claim 11 in which said acting means comprises:

a plurality of rollers;

and means continuously urging each of said rollers against the spaced portions of said belt to cause the document to be engaged against said document support means by the spaced portions of said belt.