JPS6036238A - Paper feed method and device - Google Patents

Abstract

PURPOSE:To prevent paper from being subjected to overlapped feed, and feed it in prescribed timing by forming a loop on said paper with rotation of a paper feed roller, then rotating a handling roller in the opposite direction to the paper feed direction, and thereafter releasing stoppage of the paper. CONSTITUTION:Upon paper feed, firstly with a handling roller 15 in a stopped state, a paper feed roller 10 is rotated, and only the uppermost paper is sent out. When the leading edge of the paper makes contact with the engaging part of a feed roller 16 to form loop L in itself, the paper feed roller 10 is stopped. Then, after the handling roller 15 is reversed while the paper feed roller 10 is in stopped state, the handling roller 15 is stopped while the feed roller 16 is rotated simultaneously, and the paper is caught by the feed roller 16 by making use of restoring force of the loop L and sent to the right. Hereby, paper is prevented from being sent overlapped and fed in prescribed timing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper feeding method and apparatus suitable for printing machines, copying machines, etc. that require paper feeding at a predetermined timing. It is an object of the present invention to provide a paper feeding method and a device therefor that prevent double feeding of paper by temporarily reversing a separating roller disposed opposite to a paper feeding roller.

2. Description of the Related Art In a paper feeding device, it is known to prevent double feeding of sheets using a reversing roller, and many proposals have already been made. For example, in the devices disclosed in Japanese Patent Publication No. 43-2G886 and Japanese Patent Application Laid-open No. 55-35716, the first
As shown in the explanatory diagram J, there is a paper feed roller 10 at the top with a large coefficient of friction with the paper, and oppositely located below there is a reversing roller 11 with a small coefficient of friction with the paper. The circumferential speed of the paper roller 10 is set to be greater than the circumferential speed of the reversing roller 11, and the paper is fed between both rollers. In this device, since the reversing roller 11 always rotates in the opposite direction while the paper feed roller 10 is rotating, it is quite effective in preventing two sheets of paper from being fed, that is, double feeding. However, even when a sheet of paper is fed normally, frictional forces in opposite directions act on both sides of the paper, such as sliding friction, which may cause damage to the paper surface depending on the nature of the paper surface, or had drawbacks such as not being able to feed paper. Furthermore, once a double feed condition occurs, the paper feeding timing must be deviated in order to resolve the problem, so it cannot be used for purposes that require paper feeding to occur at a predetermined timing. there were.

The device shown in FIG. 2 was proposed in Japanese Patent Publication No. 50-16974, and the paper fed by the paper feed roller 10 between the feed roller 12 and the reversible feed roller 13 is one normal sheet. In the case of feeding, it is fed as is to the right in the figure. When a double feeding condition occurs as shown in the figure, a detection device 14 placed in front of the feed roller 13 detects this, and a clutch provided on the shaft of the reversible feed roller 13 is actuated by an electric circuit (not shown). Then, the roller is reversely rotated in the opposite direction as shown by the dotted arrow to send the lower paper back to the left in the figure, thereby eliminating the double feeding of the paper.

This device can be used for thin paper without damaging the surface of the paper, but on the other hand, it is necessary to adjust the sensitivity of the detection device 14 according to the thickness and color tone of the paper. It has the drawback that it requires a dedicated electric circuit, a complicated latching device, etc. to be added to the rotating shaft. In addition, when a double feed situation occurs, in order to resolve this situation, it is possible to prevent paper feeding timing from being incorrect.
This system has the same drawback as the system shown in FIG. 1 in that it cannot be used for purposes that require paper feeding at a predetermined timing.

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel paper feeding method and device that can eliminate the drawbacks of the known devices, prevent double feeding of paper, and feed paper at a predetermined timing. shall be.

In order to achieve this object, the method of the present invention includes a paper feeding section including a paper feeding roller and a separating roller, and a paper stopping section disposed at a predetermined distance from the paper feeding section. and a paper guide disposed between the paper stop part, and the paper feed roller is rotated to form a paper loop between the paper feed part and the paper stop part, The separating roller is then rotated in a direction opposite to the paper feeding direction, and then the paper stopping by the paper stopping portion is released.

Furthermore, the apparatus of the present invention includes a paper feeding section including a paper feeding roller and a separating roller, a paper stopping section disposed at a predetermined distance from the paper feeding section, and the paper feeding section and the paper stopping section. In the paper feeding device, the separating roller is normally stopped and rotates intermittently in reverse, and the paper guide assists in forming a paper loop. It is characterized by:

Hereinafter, the present invention will be explained in detail based on preferred embodiments shown in the accompanying drawings. FIG. 3 is a side view for explaining one embodiment of the paper feeding method and apparatus of the present invention. In the figure, 10
is a paper feed roller, which is made of a material such as elastic rubber that has a large coefficient of friction μl against the paper, and if necessary, grooves may be formed on the surface of the roller. Reference numeral 15 denotes a separating roller, the surface of which is smooth, the friction coefficient μ2 against the paper is smaller than the above-mentioned μl, and the peripheral surface of the roller is made of a material such as polyurethane, which has a friction coefficient μ2 between the sheets and is larger than the friction coefficient μ3. is coated.

The paper feeding roller 10 and the separating roller 15 constitute a paper feeding section.

Reference numeral 16 designates a pair of feed rollers, one of which has its surface coated with an elastic material such as rubber, and which are pressed against each other by a pressure spring 17. The feed roller 16 is intermittently driven and rotates in the direction of the arrow in the figure at the timing shown in (a) above, and functions as a paper stopping section in the present invention during the period when its rotation is stopped. Reference numerals 18 and 19 are both paper guides, and the right end side in the figure is such that the front end of the paper faces the engaging generatrix of the pair of feed rolls 16. The lower paper guide 18 is provided with a stepped portion to facilitate the formation of a paper loop, which will be described later, but this is not limited to the illustrated shape. The upper paper guide 19 is also provided with a bent portion on the paper feed section side to help form a paper loop.

The sorting roller 15 is supported by an arm 21 that can freely swing around a drive shaft 20. The arm 21 is pulled by a spring 22, and by adjusting the tension of the spring, the sorting roller 15 and the skin roller 10 are separated. The pressure force between the two can be adjusted depending on the thickness and quality of the paper. Drive shaft 2
A ratchet device consisting of a ratchet wheel 23 and a ratchet claw 24 is attached to the drive shaft 20, and when the drive shaft 20 rotates according to the timing described later, the belt 2
5, the separating roller 15 is reversely rotated in the direction of the dotted arrow. On the other hand, when the drive shaft 20 does not rotate, the ratchet pawl 24 is set so that the separation roller 15 does not follow the rotation of the paper feed roller 10 in the clockwise direction.
rotation is prevented. Illustrated examples to aid understanding! Although the description has been made by disposing a radiator device on +l[1120], it is of course possible to use a one-way rotation clutch on the drive shaft 20.

FIG. 4 shows a paper feed roller 10, a separation roller 15, and a feed roller 16 which serves as a paper stop in the embodiment of FIG.
FIG. 2 is a diagram showing the timing of each operation. In the figure, the horizontal axis shows the passage of time, and the parts where the lines of each member stand up indicate that they are in the operating state. In the figure, the line from line 8 to 8 indicates one cycle in which one sheet of paper is fed, and point A is at the predetermined timing when paper feeding is required for printing machines and copying machines. Quite a lot. Please note that this diagram only shows the timing of the operating order of each member, and does not accurately correspond to the actual operating time or the length of paper being fed, as explained below. .

Hereinafter, the manner in which paper is fed by the apparatus of the present invention according to the timing shown in FIG. 4 will be explained with reference to the operation diagrams of FIGS. 5 and 6. In the following operation diagrams, details inside the arm 21 including the drive shaft 20 are omitted. In the timing diagram in Figure 4, the starting point is 8 when viewed from the side of the printing machine or copying machine that receives the paper feed.
It would be appropriate to begin the explanation of the paper feeding device of the present invention with the point (a) in which the paper feeding roller 10 operates.

When the paper feed roller 10 rotates in the direction of the arrow in FIG. 5 in response to the signal (a), the separation roller 15 stops at this time. As with the device that combines a paper feed roller and a paper separation plate, only the topmost sheet is sent out.

When the front end of the paper comes into contact with the engagement generatrix of the stopped feed roller 16, the paper forms a paper loop, and at this point the signal (b) is generated and the rotation of the paper feed roller 10 is stopped. Stop. (b) By receiving the signal,
The separating roller 15 starts to reversely rotate in the direction indicated by the dotted line arrow in FIG. 3, while the paper feed roller 10 remains stopped.

At this time, the friction coefficient of both rollers against the paper is μl〉μ2
Once the handling roller 15 starts rotating, its friction coefficient μ2 becomes a smaller dynamic friction coefficient, so the difference in the above relationship becomes even larger, and even if the handling roller 15 reverses, it will not idle. The paper will not be sent back to the left.

Even if the paper is sent back to the left a little, the size of the paper loop L becomes slightly smaller and the front end of the C1 paper still contacts the engaging generatrix of the feed roller 1G. Next, when the signal (c) is issued in FIG. 4, the handling roller 15
stops, and at the same time, the feed roller 16, which had previously served as a paper stopper, begins to rotate, and uses the restoring force of the paper loop to grip the paper that was in contact with its engagement busbar. The paper is fed to the right as shown in FIG.

As seen in FIG. 6, at this time, the paper feed roller 10 idles as the paper advances due to the action of a one-way rotation clutch provided on its shaft, while the handling roller 15 rotates as shown in FIG. It is immovable due to the ratchet device. When the feed roller 16 rotates for a period that can feed the longest paper among the sheets to be used, a signal (a) is generated and the feed roller 16 stops, and at the same time the paper feed roller 10 starts operating again and the next paper is fed. The next step is to move on to the paper feed cycle.

The above description has been of how one sheet of paper is normally fed according to the timing shown in FIG. 4. Next, the operation of the apparatus of the present invention when a double feeding condition occurs will be explained with reference to the drawings. When the paper feed roller 10 starts rotating in response to the signal (A), sometimes two sheets of paper overlap and are fed out in a multi-feed state, as shown in Fig. 7. When this happens, as the paper feed roller 10 rotates, the two sheets of paper are fed out overlapping each other, and just before the signal (b) is issued, the front edge of the paper has stopped, as shown in Figure 8. It comes into contact with the engagement generatrix of the feed roller 16 to form a paper loop L. When the signal (B) is issued, the paper feed roller 10 stops and the separation roller 15 starts rotating in reverse, the upper paper is fed. The paper on the positive side is stopped in the same position due to the large friction coefficient μm of the roller 10, while the paper on the positive side is rotated by the separating roller 15, which has a friction coefficient μ2 larger than the friction coefficient μ3 between the sheets, FIG. As shown in the figure, the paper starts moving to the left in the figure, and once it starts moving, μ3 becomes an even smaller coefficient of kinetic friction, so the paper is smoothly sent to the left and returns to its original position on the paper table. When the signal (c) is issued, the sorting roller 15 stops and the feed roller 16, which had been stopped until then, starts rotating, so that the upper paper that was stopped in that position and forming the paper loop L is
The sheets will be fed in the same way as in the case of normal one-sheet feeding shown in FIG.

10 to 12 are diagrams for explaining paper feeding in another embodiment of the present invention.

To explain the configuration of this embodiment with reference to FIG. 10, in this embodiment, the feed roller 1G is always rotating in the direction of the arrow, and a part of the paper guide 18 is located on the paper feed roller 10 side in front of the feed roller 1G. The tip 26a of the paper stop lever 26 protrudes into the paper path by cutting out the paper stop lever 26, and the tip 26a serves as a paper stop portion. The paper stop lever 26 is pivotally supported by the shaft 21, and has one end connected to the spring 2.
8 and is urged such that the leading end 26a always protrudes into the paper path. Paper stop lever 26
One end is connected to a mover of a solenoid 29, and when the solenoid is energized by a signal to be described later, the tip 26a of the paper stop lever 26 is retracted from the paper path.
It is designed to release the paper from stopping.

FIG. 10 shows the state just before the signal (b) in FIG. 4 is issued when the apparatus of this embodiment happens to be in a double-feed state, and the front end of the paper is in contact with the tip 26a of the paper stop lever 26. , it can be seen that the paper forms a paper loop L. When the signal (B) is issued, the paper feed roller 10 stops, and the separation roller 15 reverses, the lower paper moves smoothly to the left as shown in FIG. 11, as described in detail in the previous embodiment. The paper is sent back to the paper tray and returned to the paper table. Next, when the signal (c) is issued, the sorting roller 15 is stopped, while the solenoid 29 is energized and the paper stop lever 26 is energized.
is rotated clockwise in the figure to retract its tip 26a from the paper path. Since the leading edge 26a has escaped from the paper path, the paper is moved by the restoring force of the paper loop L.
The front end of the paper is gripped by the constantly rotating feed roller 16, and paper feeding is started as shown in FIG. In this state, the solenoid 29 remains energized until the next signal (i) is issued, so the lever tip 26a does not interfere with paper feeding, and the paper feed roller 1 is operated by the one-way rotation clutch. , the idle rotation following the paper is similar to the surface writing embodiment. When signal (a) is issued,
The solenoid 29 stops being energized, the paper stop lever 2G is pulled by the spring 28 and rotates counterclockwise around the shaft 27, and the tip 26a of the paper stop lever 26 protrudes into the paper path and returns to the paper stop section. form. At the same time, the paper feed roller 10 begins to operate in response to the signal (a), and the next paper feed cycle begins. In this example description,
Although a description of the normal feeding of one sheet of paper has been omitted, those skilled in the art will be able to easily understand Dotsu-C from the above description.

The paper feeding device of the present invention is shown in the timing diagram of FIG.
In response to each signal shown in (b) and (c), each member is activated to achieve the purpose of preventing double feeding of sheets. These signals can be easily obtained by using a part of the main body mechanism of a printing machine, copying machine, or the like used together with the paper feeding device of the present invention. Normally, printers, copiers, and other devices are equipped with a timing mechanism that properly operates each part of the equipment, so if you use this mechanism, the signals in (a) to gc above can be easily obtained. For example, if it is a device that uses a cam device as a timing mechanism, all you need to do is make some modifications to the existing cam, or add a new cam plate and microswitch. In the case of an electronically controlled device incorporating an electronic control device, it is possible to easily extract the signals (a) to (c) above from its central processing element, the so-called CI) U.

In the timing diagram of Figure 4, from signal (A) to (mouth)
The length of time until the paper is fed by the paper feed roller 10 is
The waste paper is determined so as to form a paper loop L of an appropriate size during this time. If the size of the paper loop L is too large, it will be difficult to obtain restoring force, and if it is too small, the purpose of the present invention cannot be achieved. It is preferable to set this time so that a paper portion that is approximately 40% longer is fed. Next, the length of time from signal (b) to signal (c) is set to be as short as possible since the paper is fed in the opposite direction to the original purpose of the paper feeding device. However, in the present invention, since the double-fed sheets must be returned to the paper table within this time, the apparatus is designed so that the reversal speed of the separating roller 15 is high. Increasing the circumferential speed of the sorting roller 15 changes the friction coefficient μ2 during normal feeding of one sheet of paper and the friction coefficient μ3 used when resolving double feeding to a smaller dynamic friction coefficient. This contributes effectively and further ensures the effects of the present invention. Furthermore, the length of time from the signal (c) to the next cycle signal (a) is processed by a printing machine, a copying machine, etc. used in combination with the paper feeding device of the present invention.
This will naturally be determined by the processing time for the largest sheet of paper, so it is best to match this. Equipment such as printing machines and copiers generally have a certain blank time after processing one sheet of paper before they need paper for the next cycle. The length from ) to c) is designed so that it fits within this blank time.

In the explanation of the operation of the above-mentioned embodiment, it was explained that when one signal is issued according to the timing diagram of FIG. 4, one member stops and the other member starts operating at the same time. For this purpose, it is not an essential condition that both members be activated at the same time by the same signal. For example, the paper feed roller 10 may start rotating to feed the next sheet before the paper has been completely fed by the feed roller 16, so that the two may be operated in an overlapping manner using separate signals. . In addition, the handling roller 1
5 stops, the paper stop section operates and the paper is fed by the feed roller 16. In order to create an appropriate time lag between these steps as necessary, the separation roller 15 is first activated by the signal (C). It is also possible to stop the paper, and then operate the paper stop section with a slight delay using a separate signal (C'). As described above, the timing diagram in FIG. 4 is shown as an example for explaining the embodiment, and it is understood that the operational relationship between each signal and each member is not limited to this. Should.

As detailed above, according to the paper feeding device of the present invention, the following excellent effects can be obtained.

(1) In the present invention, since the frictional force of the rollers on both sides of the paper does not simultaneously act as sliding friction in opposite directions, even thin paper can be fed without any problems; Furthermore, there were no accidents such as damage to the paper surface.

(2) The present invention does not require a double-feed detection device, a dedicated electric circuit, or a complicated latch for rotating the rollers in the forward and reverse directions, unlike known double-feed prevention paper feeding devices.
Therefore, it is not necessary to adjust the sensitivity of the detection device according to the thickness (At) and color tone of the paper, and the device can not only be simplified and manufactured at low cost, but also easy to operate and double feeding can be reliably prevented.

(3) In the present invention, paper can be fed by operating each part of equipment such as a printing machine or a copying machine using a timing mechanism, so that paper can be fed at a predetermined timing. Unlike conventionally proposed devices, there is no possibility that the paper feeding timing will be out of order in order to eliminate the double feeding condition.

<4) Double feeding of paper occurs because a phenomenon of close contact occurs between the paper surfaces for some reason, but in the present invention, paper that is double fed and forms a paper loop First, a gap is created between the sheets due to the formation of a paper loop, which eliminates this adhesion phenomenon, and then they are separated from each other by the reverse rotation of the separating roller, and the remaining double-fed sheets are smoothly returned to the paper table. It will be done. That is, the formation of the paper loop of the present invention greatly contributes to eliminating the phenomenon of close contact between sheets, and in addition to the reverse rotation of the separating roller, the effect of preventing double feeding is further ensured.

[Brief explanation of drawings]

Figures 1 and 2 are side views showing a conventional paper feeding device;
FIG. 4 is a side view showing an embodiment of the paper feeding device of the present invention; FIG. 4 is a diagram showing the operation timing of each member in the present invention; FIGS. 5 and 6 are FIG. 3; normal paper feeding of the illustrated device. Figures 7, 8 and 9 are side views showing the pulling operation into the state.
The reason for this is that Figure 3 is a side view showing the operation of the paper feeding device in the state of double feeding of sheets, and FIGS. FIG. 10... Paper feed roller 11.12.13... Feed roller 14... Detection device 15... Sorting roller 1
6...Feed roller 17...Press spring 18, 19.
...Paper guide 20...Drive shaft 21...Arm
22... Spring 23... Car to Ratchets 24...
- Ratchet pawl 25...Belt 26...Paper stop lever 27...Shaft 28...Spring 29...Solenoid Patent applicant Dubro Manufacturing Co., Ltd. Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 10 Figure 11

Claims (1)

[Claims] (1) a paper feeding section consisting of a paper feeding roller and a separating roller; a paper stopping section disposed at a predetermined distance from the paper feeding section;
In a paper feeding device comprising a paper guide disposed between the paper feeding section and the paper stopping section, the paper feeding roller is rotated to form a paper loop between the paper feeding section and the paper stopping section. , the separating roller is then rotated in a direction opposite to the paper feeding direction, and then the paper stopping by the assembly stopping section is released. (2> A paper feeding section consisting of a paper feeding roller and a separating roller,
In a paper feeding device that includes a paper stop section disposed at a predetermined distance from the paper feed section, and a paper guide disposed between the paper feed section and the paper stop section, the separating roller is usually A paper feeding device characterized in that the paper feeder is stopped and intermittently operates in reverse, and the paper guide is adapted to assist in forming a paper loop.