JPS63288858A - Sheet conveyor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a sheet conveying device, and is particularly useful for, but not limited to, feeding copy sheets in a copying machine. The apparatus has a set of rollers forming a sheet-feeding nip and is of a type that is more advantageously used in conjunction with a sheet-receiving means for receiving sheets continuously fed from the nip. .

(Prior Art) Such a sheet feeding device is normally used in a xerographic copying machine together with a stack receiving means having a tray for receiving copy sheets fed in a nearly horizontal direction. Trays are often tilted either upwardly or downwardly in the direction of sheet feeding. This angle of inclination is usually less than 45°. Generally, the copy sheet is fed from the process of the copier with the front side facing up, and if the input order of the documents to be copied is 1 to n, and the documents are copied in that order, then the copy sheet forms an image on the surface with a JIII number from 1 to n and is discharged from the processing process. A simple catch tray constructed to receive each copy successively, face up, would thus receive sheet 1 into the tray first, and then successively pass sheets up to sheet n, next to the previous sheet. A stack is thus formed with sheet 1 at the bottom and sheet n at the top. The stack removed from the tray is necessarily 1 in the input order (1
to n), that is, from n to 1. As described below, the order from the top of the sheet is 1 to n.
One way to obtain a stack is to flip each sheet so that it fits face down in the catch tray. The completed stack in the output tray has each sheet facing downwards, and by flipping the entire stack over to create a stack with each sheet facing upwards, the stack is sized from 1 to n, just like the first stack. Get the stack in order.

Due to the inconvenience of the stack being ordered from n to 1,
Various methods have been tried to solve this problem and provide a stack with an order from 1 to n, including the above-mentioned sheet flipping method, i.e. feeding the sheets successively to the bottom of the stack. One of them is a method that includes a process.

An example of a sheet reversing machine for copy sheets discharged from a copying machine is disclosed in U.S. Pat. No. 4.3(16). No. 757, and in this example, a sheet discharged horizontally from a fixed shaft feed roller in the output section of a copying machine is deflected downwardly by a fixed deflector.

The leading edge of the sheet, which is deflected downward, falls onto the catch tray, and then the trailing edge of the sheet falls in the direction of sheet feeding, and the sheet is in an inverted state on the catch tray.

Another example of a sheet reversing machine for copying machines is the British Patent No.
．． No. 475.094. In this example, a set of feed rollers is mounted on the frame such that all roller bears can be rotated about their axes through the nip. When the sheet enters the nip, the rollers stop feeding and
The frame rotates 180° and the rollers (now rotating in the opposite direction) feed and eject the inverted sheet in the normal feeding direction.

(Problems to be Solved by the Invention) Both of these sheet reversing techniques lack reliability and have somewhat complicated mechanisms. Moreover, it is unsuitable for use in copiers that use copy sheets of various sizes.

Another problem with sheet transport devices that collect sheets in a tray is the difficulty of feeding sheets of different lengths into the tray. If the sheet transport device that feeds the sheets into the tray is far enough away from the edge of the tray to accommodate the longest sheet, then shorter sheets will fall off, never reach the edge, or will not be able to reach the edge. It may also collide with the trailing edge of the previous stacked sheet.

This is true even if the catch tray is angled downwardly from the sheet entrance, as is usually the case.

Conversely, if the sheet 1 general feeder is close enough to the edge, relatively short sheets will be stacked correctly, but it will be impossible to stack sheets longer than a certain length. To suit the range of sheet sizes typically used,
Two or more sheet transport devices are used with baffles placed between the devices. All sheets are fed by a first set of feed rollers, and shorter sheets are further fed by a second set of feed rollers.

After a relatively long sheet passes a first set of rollers, it is deflected by a baffle plate and passes a second set of rollers. The problem with this device is that it is well suited for sheets having two lengths determined by the positions of the two sets of rollers, but is unreliable for sheets of intermediate length. For this reason, several additional sets of feed rollers and baffles are usually used to accommodate the various sheet sizes. This makes the mounting equipment more complex, more expensive, and less reliable. Another method for accommodating the normal range of sheet sizes is uphill stacking, ie, feeding the sheets on a tray with an uphill slope. However, this method of stacking using an upward slope is also inappropriate when the leading edges of the stacked sheets must be aligned, for example when they are subsequently copied again or stapled together.

In practice, both of these methods require more parts and space compared to conventional sheet transport devices that feed sheets into generally horizontal trays.

The present invention provides a relatively simple but reliable stack forming means for forming a stack of sheets in the order 1 to n from input sheets in the order 1 to n, as well as sheets of a range of sizes. It is intended to provide a means for reliably stacking the paper into conventional trays.

SUMMARY OF THE INVENTION The present invention comprises a set of rollers forming a sheet transport nip and adapted to engage the leading edge of a sheet fed thereto when in a starting position; and means for causing one roller to move in a trajectory relative to the other roller, and for changing the direction of movement of the sheet while the sheet is progressing through a nip. It is.

In one apparatus using the present invention, the nip between the rollers is oriented substantially horizontally in its starting position to receive the fed and crushed sheet, and in said orbital motion, the nip between the rollers At the position farthest from the seat, the sheet is oriented so as to travel approximately vertically downward. In this version, a sheet inverting stacker is provided so that the apparatus is used with a tray that receives sheets generally vertically. In a modified version of this type of machine, the sheet receiving tray is tilted slightly above the horizontal (preferably upwards) and the nip orbits over a position ranging from 90° to 180° from its starting position. ,
This inverts the sheets and feeds them into a generally horizontal stack.

In another apparatus using the present invention, a sheath) 11 feeder is used with a tray that receives sheets generally horizontally;
The sheet stacking device is capable of reliably stacking sheets of a wide range of lengths without adjusting the position of rollers or trays.

The device according to the invention is simple, reliable and compact. and accommodates a wide range of paper weights and sizes.

(Example) A sheet conveying device according to the present invention will be described by way of an example with reference to the drawings.

1a-1d, a copy sheet 11 is transferred from a copying machine 10, such as a xerographic copying machine, to a sheet feeding nip 12 comprising a set of feeding rollers 13, 14.
is fed to the collection tray 15 via the. Lower roller 1
3 is a driven roller, and the upper roller 14 is an idle roller. Copy sheets 11 are continuously fed, face up, toward nip 12 in a generally horizontal direction.

A sensor (FIG. 1a), such as a microswitch or an electro-optic sensor, detects the leading edge 17 of the sheet 11 and activates a cam-actuated track roller mechanism or other suitable drive mechanism, such as a belt drive as described below. Start it. This mechanism causes the upper roller 14 to orbit around the lower roller 13 in a clockwise direction.

This orbital motion occurs while the sheet is being fed by the rollers, and as shown in Figure 1b, the sheet 11 is fed approximately parallel to the nip 12 when the leading edge of the sheet passes between the rollers. .

The shroud 18 of the upper roller 14 moves with it.

As shown in FIG. 1c, the upper roller 14 continues its orbital motion until the nip 12 reaches a substantially vertical orientation, while the feed roller continues to feed the sheet 11. Nip 12
The sheet 11 is fed almost vertically downward at the point where the sheet 11 reaches the almost vertical direction. The upper roller 14 remains in this position (by action of the cam mechanism) until the leading edge 17 of the sheet 11 contacts the bottom 19 of the tray 15 (FIG. 1d). From this point on, the orbital motion of the upper roller 14 (and shroud 18) is reversed and the axis of the upper roller 14 begins to move counterclockwise around the lower roller. During this time, the lower roller 13 continues to rotate in the direction in which the sheet is fed, causing the sheet 11 to bend as shown in FIG. 1d. The trailing edge 20 of the sheet 11 is fed through the nip 12 as the top roller 14 moves back toward its starting position, so that the trailing edge of the sheet is oriented approximately horizontally relative to the top of the tray. effectively sheet 1
1 can be stored in the tray 15.

Due to the fact that both the leading edge of the sheet is fed reliably into the tray 15 and does not fall out of the tray, and the trailing edge of the sheet is fed with a storage movement that facilitates storing the sheet in the tray, The stack becomes reliable. Additionally, sheets of a wide range of sizes and papers of a wide range of weights can be processed without the risk of misalignment or paper jams.

A stack retainer 21 is attached to the bottom 1 of the tray 15 to help maintain the stack vertically within the tray 15.
The tray 15 is moved in and out to hold against the sheets in the tray 15 by a drive which is pivotally mounted adjacent to the upper roller 14 and is linked to the orbiting mechanism of the upper roller 14. When the upper roller 14 is in the starting position (1a
Figure) The stack presser 21 presses the sheets in the tray 15 toward the rear of the tray, and the tray and stack presser are arranged so that the sheets are oriented in the vertical direction. This makes the stack stiffer, like a beam, and allows the stack to stand on its edges. As the orbital movement of the upper roller 14 begins (FIG. 1b), the stack retainer 21 leaves the tray and is furthest away from the tray when the nip 12 is oriented substantially vertically (FIG. 1C). Therefore, the fed sheets 11 are stored in the tray without being disturbed. As the upper roller 14 begins to move back toward its starting position (FIG. 1d), the stack presser 21 again presses down on the stack and deflects the newly fed sheet 11.

The mechanism for orbiting the upper rollers also drives the alignment arm 22 (Fig. 3.4), which is used after the sheets have been ejected from the nip 12 and when the stack presser 21 is Starts moving before touching the stack. This action ensures that the vertical edges of the stack in tray 15 are accurately aligned.

2.3.4 shows the integration of a sheet stacking device into the finishing station 30 of the xerographic reproduction machine 10. Here, the storage tray 15 of FIG. 1 is represented as two partially folded trays, each consisting of a pair of support arms 15a, 15b. The deflection created by the stack presser 21 is caused by a set of support arms 1
It is formed by moving the stack presser into the space between 5a and 115b. When the stored east is completed, the support arms 15a, 15b are folded downward, and the east falls into the catch tray 31 having a larger capacity. By moving one of several sets of copy sheet storage east farther than the east of the pond using the edge alignment arm, an offset function can also be exerted.

Referring to FIG. 4, the edge-aligned sheet reaches position 1 and is fed to position 2 by edge alignment arm 22. Storage East is sent alternately to offset position 3 and position 4 before being ejected.

As part of the finishing station, a stapler 32 is mounted adjacent the lower corner of the storage tray in which the copy sheets are stored edge-to-edge. If you need to staple a stack of copy sheets, use -
The stapler operates each time the east is stored, and then
The edge alignment arm moves to force the stapled bundle out of the throat of the stapler into one of two offset positions 3 or 4. As shown in FIG. 3, the stapler is installed so that its anvil 33 is on the side where the mechanical part of the storage tray is located, and the movable parts and drive mechanism 34 are located inside the housing 35 (second figure).

FIG. 5 shows an example of a drive device that causes the rollers to perform orbital motion. The driven roller 13 and the idle roller 14 are attached to a drive shaft 40 and an idle shaft 41, respectively. The shaft 40 is rotatably attached to the end surface 4 of the support frame 44.
2.43 and is driven by a drive pinion 45. This drive pinion 45 is driven by a drive belt 46, for example. In this way, when the drive belt 46 operates, the drive roller 13 rotates, and the idle roller 14 further rotates due to the friction of the contact surface. The idle roller 14 is rotatably supported on an idle shaft 41, or is fixed to a shaft 41 rotatably supported on end surfaces 42 and 43 of a support frame 44. In order to enable the idle roller 14 to perform an orbital movement about the central axis of the driven roller 13, the frame 44 performs a pivoting movement about the central axis of the drive shaft 40. This pivoting movement of the frame 44 is caused by a drive pinion 47 fixed to the end face 42, and the drive shaft 40 is rotatably supported relative to the drive pinion 47. A drive belt 48 is wound around a pinion 47, and when the drive belt is actuated, the pinion 47 and therefore the frame 4
4 begins a rotating movement.

Referring now to FIG. 6, this is a diagram of a xerographic copying machine with double-sided copying capability using a buffer tray using a sheet transport device according to the present invention. FIG. 6 shows (diagrammatically) only those parts relating to the movement of the copy sheet through the transport device. Copy sheets are fed by feed rollers 50 from a sheet stack 51 placed on a stack carrier 52 that can be raised and lowered. The sheet is guided to a set of first transport rollers 53 as shown by arrow A, and further to a set of second transport rollers 54 as shown by arrow B. Transport rollers 54 transport the sheet (in the direction of arrow C) to a xerographic transfer station 55 where the developed electrostatic latent image is transferred from photoreceptor belt 56 to the copy sheet surface.

The sheet advances along with the transferred image in the direction indicated by the arrow, and passes through a fixing device 157 consisting of a heating roller and a backup roller. The fusing mechanism 57 fixes the developed image on the copy sheet surface, and the copy sheet is then directed to eject roller 58 as indicated by arrow E.

When the image is formed only on one side of the copy sheet (
(i.e., for single-sided copying), the sheet is fed as indicated by arrow F via ejection rollers 58 to an appropriate ejection tray (not shown).

On the other hand, when an image is formed on both sides of a copy sheet (i.e. duplex copying), the sheets are circulated so that the image is transferred to the other side as well, as discussed below. state

For double-sided copying, rather than passing the sheet all the way through the ejection rollers 58, the ejection rollers are stopped just before the trailing edge of the sheet reaches the nip between the ejection rollers. Thereafter, the discharge roller is reversed, and the sheet is returned through the discharge roller as indicated by arrow G. The ejection roller and the sheet guide plate surrounding it are such that when the ejection roller is reversed, the sheet moves to the fixing mechanism 5 as shown by arrow H.
7, but is arranged so that it is fed back to the lower guide throat 59. Then the sheet is
It passes through a nip created by a set of conveyance rollers 60 that constitute the sheet conveyance device according to the present invention (arrow I).

When making a double-sided copy of one sheet from the original, use the transport roller 6.
0 remains stationary, and the sheet is guided by the gate 61 along the sheet guide 62 (arrow J) in the direction of the first conveyance roller 53 (arrow K). When the sheet approaches roller 53, the imaged side faces upward, so it passes through the xerographic mechanism a second time (
Arrows B and C.

D, E), the surface on which the image is formed faces downward;
Therefore, an image can be transferred onto a blank surface on which no image is formed. After the second pass, the sheet with images formed on both sides is carried out of the apparatus by discharge rollers 58 (arrow F) and placed in a discharge tray.

When a large number of copy sheets are to be imaged on both sides - the first side of a set of copy sheets is imaged first, and then the other side is imaged, the sheets are placed in a duplex buffer tray. 63, image formation of the first surface is performed. To achieve this, the gate 61 is raised, as shown by the dashed line, so that sheets shorter than a predetermined length are fed into the buffer tray (arrow L), and the axis of the roller 60 is such that the sheet is fed into the buffer tray 63. It remains stationary while being fed. A stack of sheets is formed in a buffer tray 63 whose bottom is raised to feed the top sheet of the stack to buffer tray feed rollers 64 . The sheet fed by the roller 64 is guided to the first conveyance roller 53 (arrow Q)
A second circulation is performed in the same manner as for double-sided copying.

Finally, for sheets longer than a predetermined length, instead of keeping the axis of the transport roller 60 stationary during sheet feeding, the roller is first stationary and then orbited as described above. Let it happen. When the axis of the idle roller (the upper roller of roller 60 in FIG. 6) performs a clockwise orbital motion about the drive roller (the lower roller of roller 60), this causes the arrow MXN
Or the sheet is fed onto the tray as shown in P. Here, arrow P represents the trajectory for the longest sheet. In this manner, sheets of a wide range of lengths can be stored in the buffer tray, and sheets may be longer than the distance between the edge of the buffer tray closest to the feed roller 64 and the nip of the roller 60. can. Therefore, when a long sheet is fed through the rollers 60, the leading edge of the sheet is first placed on the buffer tray 64 directly below the feed rollers 64.
Touch the end of 3. At about the same time, when the roller 60 begins its orbital motion, the trailing edge of the sheet is first guided substantially downward toward the tray 63, and finally, when the roller that is orbiting comes to the position indicated by the broken line, it is moved as indicated by the arrow P. As shown,
It is directed away from the far end of the tray 63.

As a result of this storage movement, the sheet is stored in the tray. Even sheets that are considerably longer than the tray can be stored in the tray without increasing the sheet trajectory or adding new baffles or feed rollers. After sheet storage, the orbital motion of rollers 60 is reversed, and by the time the leading edge of the next sheet is reached, the nip of rollers 60 has returned to its starting position.

[Brief explanation of the drawing]

Figures 1a-1d are schematic cross-sectional views illustrating the operation of an inverted sheet stacking apparatus using the present invention. FIG. 2 is a perspective view of an inverted sheet stacking apparatus using the present invention. FIG. 3 is a schematic cross-sectional view of the device of FIG. 2, viewed from the side. FIG. 4 is a schematic plan view of the device of FIG. 2; FIG. 5 is a partial perspective view of a roller orbiting device suitable for use in the apparatus according to the invention. FIG. 6 shows a double-sided buffer tray using the present invention.
1 is a schematic diagram of a portion of a xerographic copier with duplex copying capability; FIG. (Explanation of symbols) 10... Copy machine 11... Copy sheet 12...
・Nip 13.14... Feeding roller 15...
Tray 15a, 15b...Support arm 16...
Sensor 17... Sheet front edge 18... Shrouding plate 19... Tray bottom 20... Sheet rear 1 21... Stack presser 22... Edge alignment arm 30... Finishing casing 31... Catch tray 32... Stapler
34... Drive mechanism 35... Housing 4
0... Drive shaft 41... Idle shaft 42
．． 43... End surface 44... Support frame 45.47
... Drive pinion 46.48 ... Drive belt 50 ... Feeding roller 51 ... Stack 52
... Stack carrier 53, 54 ... Conveyance roller 55 ... Transfer station 56 ... Photoreceptor belt 57 ... Fixing mechanism 58 ... Ejection roller 59 ... Guide throat 60 ... Conveyance roller 61...Gate 62...Sheet guide 63...Buffer tray

Claims (18)

[Claims] (1) a set of rollers constituting a sheet transport nip adapted to engage the leading edge of a sheet fed to the rollers when the rollers are in the starting position, and one roller; A sheet conveying device comprising means for causing an orbital movement of a sheet around the other roller to continuously change the traveling direction of a sheet passing through a nip. (2) The sheet conveying device according to claim 1, wherein the plurality of rollers are capable of performing the orbital movement around the axis of one of the plurality of rollers. (3) The method according to claim (1) or (2), characterized in that in a system in which the shafts of the two rollers are fixed, the rollers are adapted to accommodate sheets that are continuously conveyed. Sheet conveyance device. (4) Initially, the above method in which the axis of the roller is fixed, and then the method in which the roller performs the orbital movement,
4. The sheet conveying device according to claim 3, wherein the roller conveys the sheet. (5) A sheet stacking device comprising the sheet conveyance device according to any one of claims (1) to (4) and a sheet receiving tray that receives sheets conveyed by rollers. (6) The sheet stacking apparatus according to claim (5), wherein the sheet receiving tray is substantially horizontal. (7) The sheet stacking device according to claim 5, wherein the sheet receiving tray is inclined slightly upward with respect to the feeding direction of the first sheet. (8) The sheet stacking device according to claim 5, wherein the sheet receiving tray is inclined slightly downward with respect to the feeding direction of the first sheet. (9) The sheet stacking apparatus of claim (5), wherein the sheet receiving tray is substantially vertical. (10) The sheet transport device operates only as a fixed axis system for sheets shorter than a predetermined length, but for sheets not shorter than a predetermined length, it operates as a fixed axis system followed by an orbital motion. Device according to any one of claims (5) to (8) and claim (3), characterized in that it is adapted to operate as a system. (11) The nip is oriented in a substantially horizontal direction at its starting position to receive the sheet fed into the nip, and the position farthest from the starting position in the orbital motion is the position at which the first sheet is fed. Apparatus according to any one of claims 1 to 8, characterized in that it is oriented to advance the sheet in a direction substantially opposite to the direction of transport. (12) the rollers are arranged so as to be able to accommodate the sheets in the sheet receiving tray and the nip, and the end of the tray that is farthest from the direction in which the sheet is initially fed into the nip; The length of the longest sheet that can be accommodated in the tray is shorter than the length of the longest sheet that can be accommodated in the tray, so that after the trailing edge of the longest sheet is stored in the tray, the distance is 12. A device as claimed in any one of claims 1 to 11, characterized in that the device is located beyond the nip. (13) Claims (1) to (4) characterized in that the rollers are installed so that the direction of orbital motion in the aforementioned orbital motion mode is reversed during sheet conveyance.
A device as claimed in any one of the claims. (14) Claims (1) to (4) characterized in that the starting position of the roller and the position of the roller at the end of the orbital movement are determined so as to reverse the conveyed sheet. and (13). (15) At the starting position, the nip is oriented almost horizontally so as to receive the fed sheet, and at the farthest position from the starting position on the orbital movement, the nip is oriented almost vertically downward. Device according to claim 14, characterized in that it is adapted to be advanced. (16) A sheet receiving tray inclined substantially perpendicularly to the sheet conveying device according to claim (15), the lower end of which is located substantially vertically below the roller, and the upper end of which is provided with the roller in a direction substantially horizontal to the roller. As a result, the leading edge of the sheet being conveyed falls onto the bottom edge of the tray.
A sheet stacking device comprising a tray arranged so that the entire sheet is stored upside down in the tray. (17) Claims (1) to (1) wherein the roller includes a driven roller and an idle roller.
16) A device according to any one of claims. (18) A driven roller and an idle roller are attached to a shaft supported within a frame, the driven roller is rotatably attached to the frame, and the frame is configured to rotate the driven roller so as to produce the orbital movement. 18. The device according to claim 17, wherein the device is rotatably attached to a shaft.