JPH0313136B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is used in a copying machine, a facsimile machine, etc. to scan multiple originals stacked on a document table into one document.
This invention relates to an automatic paper feeding device that feeds paper into a main body one by one.

Conventional technology Conventionally, an automatic paper feeding device installed in a facsimile machine, etc., is equipped with a reversing roller that contacts the paper feeding roller with its own weight, and this reversing roller is rotated in the opposite direction to the paper feeding roller through a torque limiter. A torque limit system is in widespread use, in which a plurality of originals set on a document table are discriminated and fed one by one.

Problems to be Solved by the Invention However, in such conventional automatic paper feeders, if the leading edge of the document is set in such a way that it does not reach the paper feed roller, the document cannot be fed. It was a pain to set up. Also,
Even if the original is set correctly, the frictional force and electrostatic force between the original platen and the original may prevent the second and subsequent originals from reaching the paper feed roller, causing the automatic paper feeder to stop midway. It was hot.

The present invention was made in view of the above-mentioned problems, and
To provide an automatic paper feeder with a simple device configuration, which allows easy setting of paper, reliably feeds the set paper to the last sheet.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention moves the reversing roller in contact with the first paper feed roller to the groove-shaped holding means using the first driving force transmitting means having elasticity. In addition to holding the shaft in contact with the first paper feed roller, a second paper feed roller is provided upstream of the first paper feed roller in the document traveling direction and protrudes from a notch in the document table when the second paper feed roller is raised. The shaft is held in contact with the guide means by the elasticity of the second driving force transmission means.

Effects According to the present invention, with the above-described configuration, since the document is conveyed by the second paper feed roller to the first paper feed roller, it is possible to reliably feed the document to the last sheet.
The holding structure of the reversing roller is simple because it is held in a groove, and the holding structure of the auxiliary paper feed roller is also simple. You can get lifting power.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings.

1 and 2 are partially omitted schematic side views of an automatic paper feeder according to an embodiment of the present invention, with FIG. 1 showing the automatic paper feeder in a non-operating state, and FIG. indicates the operating state of the automatic paper feeder. Fig. 3 is a partially omitted schematic plan view showing the paper feed roller and auxiliary paper feed roller of the automatic paper feeder, and Fig. 4 is a partially omitted schematic plan view showing the reversing roller and its drive system of the automatic paper feeder. It is an abbreviated schematic plan view. FIG. 5 is a central sectional view of the reversing rollers 1a and 1b shown in FIG.

In each figure, the reversing rollers 1a and 1b are made of Jyuracon (registered trademark) and loosely inserted into the shaft 3 via sleeves 2a and 2b, and are freely rotatable and movable in the longitudinal direction of the shaft 3 together with the sleeves 2a and 2b. freely supported. Friction plates 4a, 4b made of phenol are fixed to both ends of the shaft 3, and pulleys 5a, 5b are further fixed to the outside thereof. Also axis 3
are provided with coil springs 6 for pressing the sleeves 2a, 2b against the friction plates 4a, 4b. The coil spring 6, together with the friction plates 4a, 4b and the sleeves 2a, 2b, constitutes a torque limit means interposed between the shaft 3 and the reversing rollers 1a, 1b. Both ends of the shaft 3 are supported by support plates 7a, 7.
It is held rotatably and vertically movably within vertical grooves 8a and 8b formed in the grooves 8a and 8b.

A shaft 9 rotatably supported by support plates 7a and 7b
Pulleys 10a and 10b are fixedly installed.
Belts 11a and 11b are passed between the pulleys 10a and 10b and the pulleys 5a and 5b. These pulleys 5a, 5b, 10a, 10b and belts 11a, 11b constitute a power transmission system for transmitting the rotational force of the shaft 9 to the shaft 3. Note that the belts 11a and 11b are elastic belts.

A paper feed roller 1 is placed below the reversing rollers 1a and 1b.
2a and 12b are provided. The shaft 13 on which the paper feed rollers 12a, 12b are fixed is rotatably supported by support plates 8a, 8b. A belt 18a is hung between the shaft 13, the shaft 9, and the rotating shaft 15 of the motor 14 (see FIG. 1), and by operating the motor 14, the shaft 9,
13 are rotated at the same time.

An auxiliary paper feed roller 16 is provided in front of the paper feed rollers 12a, 12b, and an elastic belt 18b is stretched between this roller 16 and a pulley 17 fixed to the shaft 13. Reference numerals 19a and 19b are guide rods that guide both ends of the shaft 20 of the auxiliary paper feed roller 16, and the shaft 20 can rotate and move up and down while being guided by the guide surfaces 21a and 21b of the guide rods 19a and 19b. . Auxiliary paper feed roller 16
A pinch roller 22 is provided above.
The shaft 23 of this pinch roller 22 is connected to the support plates 7a, 7
b is rotatably supported.

24 is a document table, the tip of which is a paper feed roller 1.
2a and 12b are terminated at the front. Further, a notch 25 is formed in a portion of the document table 24 corresponding to the auxiliary paper feed roller 16.

Note that in this embodiment, the auxiliary paper feed roller 1
6 is raised, the elastic belt 18b comes into contact with the pinch roller 23. However, by positioning the surface of the elastic belt 18b inside the surface of the auxiliary paper feed roller 16, The surface may be brought into direct contact with the pinch roller 32.

The operation of the automatic paper feeder configured as above will be explained below.

In the non-operating state, the auxiliary paper feed roller 16 is lowered as shown in FIG. 1 and is separated from the pinch roller 23. In this state, 1
A sheet or multiple sheets of a document are set on the document table 24. In this case, the leading edge of the document is
It is not necessary to insert the originals deeply until they reach 12b, and it is sufficient to set the originals so that at least the leading edges of all the originals are located closer to the paper feed rollers 12a and 12b than the pinch roller 23. Therefore, setting the original is easy.

After setting the original in this manner, when a start button (not shown) is pressed, the motor 14 is activated and the shaft 13 is rotated in the direction of the arrow 30. The rotational force of this shaft 13 is transmitted to the auxiliary paper feed roller 16 via the elastic belt 18b.
6 rotates in the direction of arrow 31. At this time, a force is generated by the elastic belt 18b to raise the auxiliary paper feed roller 16, and the shaft 20 and the guide surfaces 21a, 21
A force that raises the auxiliary paper feed roller 16 is also generated due to friction with the paper feed roller 16. Due to this force, the auxiliary paper feed roller 16 is guided by the guide surfaces 21a and 21b, and gradually rises while rotating in the direction of the arrow 31.
Finally, it rises to the position shown in FIG. 2, and pinches the original between it and the pinch roller 23.
As the auxiliary paper feed roller 16 rotates, the set original is fed in the paper feeding direction shown by the arrow 32, and the leading edge of the original comes into contact with the paper feed rollers 12a, 12b.

Note that the auxiliary paper feed roller 16 and the pinch roller 22
Since the squeezing force of the document is relatively weak, the auxiliary paper feed roller 16 (elastic belt 18b) idles after the leading edge of the document contacts the paper feed rollers 12a, 12b. Therefore, after the leading edge of the document comes into contact with the auxiliary paper feed rollers 12a, 12b, there is no fear that the document will bend to the extent that it becomes a problem.

As described above, the auxiliary paper feed roller 16 and the pinch roller 22 feed the original into the paper feed rollers 12a and 12b.
Therefore, there is no need to worry about the feeding of the original being hindered by frictional force or electrostatic force between the original and the original platen 24.

The document fed by the action of the auxiliary paper feed roller 16 and the pinch roller 22 is fed to the paper feed rollers 12a,
12b and reversing rollers 1a and 1b, the sheets are discriminated and fed one by one, and this operation will be explained below.

When the motor 14 operates, the paper feed rollers 12a,
12b is rotationally driven in the direction of the arrow 30, and at the same time the shaft 9 is rotationally driven in the direction of the arrow 33. The rotational force of the shaft 9 is applied to the belt 11a and the pulleys 5a, 5b, 1
It is transmitted to the shaft 3 via 0a and 10b, and the shaft 3 rotates in the direction of the arrow 34. The rotational force of this shaft 3 is
The torque is transmitted to the reversing rollers 1a, 1b via the friction plates 4a, 4b and sleeves 2a, 2b of the torque limit means, which frictionally engage with each other.

Here, as shown in FIG.
If there is any paper between a and 12b, or if no paper is present, the paper feed roller 12
The rotational force transmitted from a, 12b to the reversing rollers 1a, 1b becomes larger than the rotational force transmitted from the shaft 3 to the reversing rollers 1a, 1b via the torque limit means. In other words, a torque exceeding the torque limit value is applied to the torque limit means, the torque limit means idles, and the reverse rotation rollers 1a, 1b
is rotated in the direction opposite to the arrow 20 in accordance with the rotation of the paper feed rollers 12a and 12b. As a result, the paper 21 interposed between the rollers is transported in the paper feeding direction.

On the other hand, when a plurality of sheets of paper 35 are interposed between the paper feed rollers 12a, 12b and the reverse rotation rollers 1a, 1b, the rotational force transmitted from the paper supply rollers 12a, 12b to the reverse rotation rollers 6a, 6b is , is smaller than the frictional force generated between the friction plates 4a, 4b and the sleeves 2a, 2b. In other words, the value of the torque applied to the torque limit means becomes smaller than the torque limit value. As a result, the reversing rollers 1a, 1b
rotates in the direction of the arrow 34, and the paper feed rollers 12a,
Only the bottom paper that comes into contact with 12b is sent in the paper feeding direction, and the remaining papers are sent back by reversing rollers 1a and 1b in the opposite direction to the paper feeding direction.

Now, if the contact pressure between the paper feed rollers 12a, 12b and the reversing rollers 1a, 1b is large, the rotational force transmitted from the paper feeding rollers 12a, 12b to the reversing rollers 1a, 1b becomes large; If is small, the transmitted rotational force will be small. Therefore,
This contact pressure is an important factor in setting the torque limit value.

FIG. 6 is a diagram showing the relationship between such contact pressure and torque limit value. In this figure, the shaded area C
indicates an area in which the automatic paper feeder can distinguish and feed sheets one by one. For example, if the contact pressure is constant as indicated by the straight line 23, the torque limit value range in which normal automatic sheet feeding is possible is A.

On the other hand, in this embodiment, the shaft 3 is provided with grooves 8a, 8
b is supported so as to be movable up and down, and a reversing roller 1
The rotational force of a rotating shaft 9 provided on the front side of rollers a and 1b is transmitted to the shaft 3 by belts 11a and 11b, and when the reversing force is transmitted, the rotational force of the rotating shaft 9 is transferred to the reversing rollers 1a and 1b as a component of the transmitted force. the paper feed roller 12a,
The force in the direction of pressing against the reversing rollers 1a, 12b
Join 1b. Therefore, the contact pressure between the reversing rollers 1a, 1b and the paper feed rollers 12a, 12b is equal to the pressing force due to the component of this transmission force and the reversing rollers 1a, 1b.
becomes the resultant force with its own weight. The pressing force due to the component force of this transmitted force has a characteristic that it increases as the torque limit value increases. Moreover, the phenol friction plate 4 constituting the torque limit means
a, 4b and Zyuracon (registered trademark) sleeve 2
a, 2b, the dynamic friction coefficient is larger than the static friction coefficient, and the larger the difference in relative rotational speed between the shaft 3 and the reversing rollers 1a, 1b, the more
The frictional force between b and the sleeves 2a, 2b increases. Therefore, in the case of this embodiment, the contact pressure is approximately proportional to the torque limit value, as shown by the solid line 41 in FIG. Therefore, the setting range of the torque limit value that allows normal automatic paper feeding is B, which clearly falls within the range A.
Since the torque limiter is wider than the torque limiter, it is easier to set the torque limiter. Further, the torque limit value is mainly determined by the elastic force of the spring spring 6, but if the setting range of the torque limit value is widened as described above, the precision conditions of the spring spring 6 are relaxed, and no adjustment can be achieved.

Note that the lighter the reversing rollers 1a and 1b, the more
Since the setting range of the torque limit value is expanded, the setting range becomes easier.

After feeding up to the last document set as described above, when the operator presses a stop switch (not shown), the motor 14 is operated in the reverse direction for a predetermined period of time and then stopped. Note that this control may be performed based on a detection signal from a sensor that detects the presence or absence of a document on the document table 24. By reversing the motor 14, the shaft 13 is rotated for a short time in the direction opposite to the arrow 30, and as a result, the auxiliary paper feed roller 16 is lowered to the position shown in FIG.

As described above, in the automatic paper feeder according to the present embodiment, it is much easier to set a document than in the past, and it is possible to load the set document into the last one.
It is possible to reliably feed up to one sheet of paper. Moreover, since the rotational power of the paper feed rollers 12a and 12b is used to rotate and raise/lower the auxiliary paper feed roller 16,
The device configuration is simpler than the case where a dedicated power source for the auxiliary paper feed roller 16 is provided.

Although one embodiment has been described in detail above, the present invention is not limited to the above embodiment. For example, the shaft 20 of the auxiliary paper feed roller 16 may be rotatably supported at the tip of an arm member rotatably supported on the support plates 7a, 7b or the shaft 13. Similarly, the shafts 3 of the reversing rollers 1a, 1b may be rotatably supported by an arm member rotatably supported by the rotary shaft 9 or the support plates 7a, 7b.

Further, the rotating shaft 9 may be rotationally driven by a motor separate from the motor 14. However, in this case, in addition to the weight of the reverse rotation rollers 1a and 1b, the weight of the arm members will also be added to the paper feed rollers 12a and 12b, so the torque limit value should be set so that the total weight of these is as light as possible. Desirable for widening the range.

Further, the rotating shaft 9 may be rotationally driven by a motor separate from the motor 14. However, since the number of motors in the above embodiment is reduced, it is of course advantageous in terms of cost reduction and miniaturization of the device.

Further, in the above embodiment, the materials of the friction plates 4a, 4b and sleeves 2a, 2b are selected so that the coefficient of dynamic friction is greater than the coefficient of static friction, but the materials may be changed to such that the coefficient of dynamic friction is less than or equal to the coefficient of static friction. It is also possible. However, the setting range of the torque limit value is narrower than in the above embodiment.

Effects of the Invention As is clear from the above explanation, the present invention
The reversing roller that is in contact with the paper feed roller is held by the first driving force transmitting means having elasticity by bringing its shaft into contact with the groove-shaped holding means, and
A second paper feed roller is provided on the upstream side of the first paper feed roller in the document traveling direction, and the second paper feed roller protrudes from the notch in the document table when it is raised. Since the document is held in contact with the guide means by the second paper feed roller, the document is conveyed to the first paper feed roller by the second paper feed roller, so that it is possible to reliably feed the document to the last sheet. I can,
The holding structure of the reversing roller is simple because it is held in a groove, and the holding structure of the auxiliary paper feed roller is also simple. This has the effect that lifting force can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a partially omitted schematic side view showing an automatic paper feeder according to an embodiment of the present invention in a non-operating state, and FIG. 2 is a partially omitted schematic side view showing the automatic paper feeder in an operating state. Figure 3 is a partially omitted schematic plan view showing details such as the paper feed roller and auxiliary paper feed roller of the automatic paper feeder, and Figure 4 is a partially omitted schematic diagram showing the reversing roller and its drive system of the automatic paper feeder. A plan view, FIG. 5 is a central cross-sectional view of the reversing roller of FIG. 4, and FIG. 6 is a diagram showing the relationship between the torque limit value of the torque limit means and the contact pressure. 1a, 1b... Reverse roller, 2a, 2b... Sleeve made by Jyuracon (registered trademark), 3, 9, 1
3, 20, 23...axis, 5a, 5b, 10a, 1
0b, 17...Pulley, 6...Coil spring, 7
a, 7b...Support plate, 8a, 8b...Groove, 11
a, 11b, 18a, 18b...belt, 12
a, 12b...Paper feed roller, 14...Motor, 1
6... Auxiliary paper feed roller, 19a, 19b... Guide rod, 21a, 21b... Guide surface, 22... Pinch roller, 24... Document table.

Claims (1)

[Claims] 1. A first paper feed roller that conveys a document, a reversing roller that contacts the first paper feeding roller, is held by a groove-shaped holding means, and is driven via a torque limiter, and the axis of this reversing roller is rotated by its elastic force. a first driving force transmitting means for holding the reversing roller in contact with the groove-shaped holding means and transmitting a driving force to the reversing roller; and an upstream side of the first paper feed roller in the document traveling direction. a second document platen having a cutout in a part thereof; a pinch roller provided above the cutout; and a second platen which protrudes from the notch when raised and pinches and conveys the document together with the pinch roller.
and a shaft of the second paper feed roller is held in contact with the guide means by its elasticity, and the driving force of the first paper feed roller is transmitted to the second paper feed roller. a second driving force transmission means;
An automatic paper feeding device comprising: the first driving force transmission means; and a drive source that supplies driving force to the first paper feeding roller.