JPS60197543A - Paper supply device - Google Patents

Abstract

PURPOSE:To make the static and dynamic frictional coefficients of a pair of frictional engaging surfaces of a torque limit means substantially equal together to restrain fluctuations in torque transmitted to a reverse roller through the torque limit means, by forming the pair of frictionally engaging surfaces of the torque limit with different spacific resins, respectively. CONSTITUTION:In a torque limit means for transmitting the torque of a shaft 10 to a reverse roller 14, composed of sleeves 15 frictionally engaged together and frictional plates 20, one of the sleeves 15 is made of acetal copolymer and the other one of frictional plates 20 is made of phenol resin so that the static and dynamic frictional coefficients of the frictionally engaging surfaces are made substantially equal together. As a result, upon starting of drive of the reverse roller or upon abrupt variations in the load of the reverse roller 14 the torque transmitted to the reverse roller 14 through the torque limit means slightly fluctuated so that disturbance in the balance between the paper supply force of a paper feed roller 11 and the separating force of the reverse roller 14 is made less to stably carry out the sorting and feed of papers.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a paper feeding device that selectively feeds stacked sheets one by one.

Conventional configuration and its problems In facsimile machines, a torque limit method is used as a paper feeder to distinguish the originals stacked on the document table one by one from the bottom and feed them to the reading unit. There is a device called.

Figure 1 shows such torque! FIG. 2 is a schematic side view showing a paper feeding device of the J′, ·y) type. In this diagram,
Reference numeral 1 denotes a paper feed roller, which is rotationally driven in the direction of arrow 2. Reference numeral 3 denotes a reversing roller, which is rotationally driven in the direction of the arrow 4 via a torque limiter (not shown), and is supported so as to rotate while contacting the paper feed roller 1 due to its own weight. Reference numeral 5 denotes a document table, on which one or more documents 6 are set one on top of the other. In order to feed the original 6 between the paper feed roller 1 and the reversing roller 3, the original 6 is provided at an angle, or a roller is provided to transport the original 6 on the original platen 5 to the left in the figure. It will be done.

Explain the operation. If there is no document 6 interposed between the paper feed roller 1 and the reversing roller 3, or if there is only one document 6 intervening, the rotational force transmitted from the paper feed roller 1 to the reversing roller 3 will be large. Since a torque exceeding the torque limit value is applied to the torque limit means, the torque limit means idles and the reversing roller 3 is rotated in the direction opposite to the arrow 4. Therefore, the intervening document is fed to the left in the figure.

When two or more documents 6 are interposed between the paper feed roller 1 and the reversing roller 23, the rotational force transmitted from the paper feeding roller 1 to the reversing roller 3 is small, and the torque applied to the torque limit means is reduced. Since the value becomes smaller than the mint value, the reversing roller 3 is rotated in the direction of the arrow 4. Therefore, among the two or more intervening originals, the bottom one that comes into direct contact with the paper feed roller 1 is fed to the left in the figure, but the remaining originals are fed back to the right. .

By the cooperation of the paper feeding roller 1 and the reversing roller 3 as described above, the original documents 6 are fed one by one.

The torque limit means used in conventional paper feeding devices with such a configuration is designed to frictionally engage the surface of the steel tank and the surface of oil-impregnated felt or acetal copolymer (Duracon). It is composed of On friction surfaces made of such materials, the coefficient of static friction is much larger than the coefficient of dynamic friction. The force transmitted to the reversing roller pulsates significantly as shown in FIG. Such large pulsations in the transmission force cause an imbalance between the separation force of the reversing roller and the paper feeding force of the paper feeding roller, resulting in a problem that normal differential paper feeding operation cannot be performed.

In addition, such large pulsations in the transmission force cause roughening of the oil-impregnated felt surface or the acetal copolymer surface, leading to an increase in the change in the average transmission force over time. Therefore, in the past, there was a problem in that the pressing force of the frictional securing surface of the torque limiter had to be readjusted periodically.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional problems, and provides a paper feeder that suppresses the pulsation of the rotational force transmitted to the reversing roller through a torque limiter and enables stable differential paper feeding operation over a long period of time. The purpose is to provide a paper device.

Structure of the Invention The present invention provides that one of a pair of friction-retaining surfaces of the torque limit means interposed in the power transmission system of a reversing roller is formed of an acetal copolymer, and the other is formed of a phenol resin, a melamine resin, or a urea resin. By making the coefficient of static friction between the frictional engagement surfaces close to the coefficient of kinetic friction, but still making the coefficient of static friction less than the coefficient of kinetic friction. , which aims to achieve the above objectives.

Description of examples Embodiments of the present invention will be described below based on the drawings.

3 is a schematic front view of a paper feeding device according to an embodiment of the present invention, and FIG. 4 is a sectional view taken along the line AA' in FIG. 3. In these figures, 11 is the paper feed roller, and the rotating shaft 1
It is fixed at 2. This rotating shaft 12 is rotationally driven in the direction of an arrow 13 by a motor not shown.

Reference numeral 14 is a reversing roller, which is rotatably supported on the shaft 10 via a sleeve 15 made of acetal copolymer (Duracon), but not movable in the axial direction.

Note that the sleeve 15 is fixed to the reversing roller 14. The shaft 10 is supported so as to be rotatable and movable in the vertical direction.

Boots IJ16a and 16b are fixed to both ends of the rotating shaft 12, and boots 1J17a are fixed to both ends of the shaft 10.

17b is fixedly installed, and a bell) 18a is installed between both pulleys.

18b is applied. Therefore, the axis of rotation 12 is
When rotated in three directions, the shaft 1o rotates in the direction of arrow 19 (FIG. 4).

The shaft 1o includes a friction plate 20 made of phenolic resin, a spring 21 for pressing the friction plate 20 against the side surface of the sleeve 15, and a stopper 22 for the spring 21.
is provided. The friction plate 2° is movable in the longitudinal direction of the shaft 1o, but cannot rotate with respect to the shaft 10. In addition, the shaft 10 is movable in the longitudinal direction of the shaft 10 in order to be able to adjust the pressing force by the spring 21, and is fixed at an appropriate position by the screw 23. It looks like this.

The sleeve 15, the friction plate 20, the spring 21, and the stopper 22 constitute l-lucriminot means. The side surface of the sleeve 16 and the side surface of the friction plate 20 frictionally engage with each other to transmit the rotational force of the shaft 10 to the reversing roller 14.

Although not shown in the figure, a document table is provided on the right side of the paper feed roller 11 in FIG. 4.The operation of this paper feed device will now be described. Paper feed roller 11 and reverse roller 1
4, if there is no original or only one original, the rotational force transmitted from the paper feed roller 11 to the reversing roller 14 is transmitted via the torque limit means. The rotational force of the reversing roller 1 is larger than that of the
4 rotates in the opposite direction to the arrow 19. Therefore, if only one original is present, that original is fed to the left in FIG.

When two or more documents are interposed between the paper feed roller 11 and the reverse rotation roller 214, the rotational force transmitted from the paper feed roller 11 to the reverse rotation roller 214 is smaller than the rotational force transmitted via the torque limit means. Therefore, the reversing roller 14 rotates in the direction of the arrow 19. As a result, among multiple manuscripts,
The bottom one that comes into direct contact with the paper feed roller 11 is fed to the left in FIG. 4, but the remaining documents are fed to the reverse roller 14.
The paper is fed back and remains in that position without being fed. In this way, the originals are fed one by one. Now, the sleeve 15 made of acetal copolymer (Duracon) and the sleeve 15 made of phenolic resin are The static friction coefficient of the friction retaining surface of the friction plate 2o is approximately equal to the dynamic friction coefficient. Therefore, when the reversing roller 14 starts driving or when the load on the reversing roller 14 suddenly changes, the rotational force transmitted to the reversing roller 214 via the torque limit means only pulsates very slightly as shown in FIG. . Therefore, the paper feed roller 11
This reduces disturbance in the balance between the paper feeding force caused by the reversing roller 14 and the separation force produced by the reversing roller 14, and stable differential feeding can be performed.

Further, since there is little pulsation in the transmitted force due to the torque limit means, the frictional engagement surfaces of the sleeve 15 and the friction plate 2o are less likely to become rough, and the secular change in the transmitted force is slightly reduced compared to the conventional one. Therefore, stable paper feeding operation can be performed over a long period of time without readjusting the pressing force of the spring 21 using the stopper 23.

Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment.

For example, the materials of the sleeve 15 and the friction plate 20 can be reversed.

One of the sleeve 16 and the friction plate 20 may be formed of an acetal copolymer, and the other may be formed of a thermosetting resin such as melamine resin or urea resin, or a thermoplastic resin such as polycarbonate or polypropylene. However, although thermoplastic resins are cheaper than thermosetting resins, the ratio of the coefficient of dynamic friction to the coefficient of static friction is smaller than when thermosetting resins are used, so from the perspective of suppressing the pulsation of the transmitted force, Thermosetting resins are generally preferred. In particular, it is preferable that the dynamic friction coefficient is approximately 0.8 times or more the static friction coefficient.

Further, the rotational force of the rotating shaft 12 may be transmitted to the shaft 1o using gears, or the shaft 1° may be driven to rotate by a motor separate from the motor for driving the rotation of the paper feed roller 11.

Further, in the above embodiment, a part of the sleeve 15 is used as one of the friction members, but a friction member separate from the sleeve 15 may be provided so as to rotate integrally with the reversing roller 14.

Further, in the embodiment described above, one sheet feeding roller 11 and one reversing roller 14 are provided, but a plurality of rollers may be provided.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, one friction-retaining surface of the torque limiting means is formed of an acetal copolymer, and the other friction-retaining surface is formed of a thermosetting resin such as a phenolic resin, Alternatively, since it is made of thermoplastic resin such as polycarbonate, the coefficient of static friction and the coefficient of dynamic friction between the frictional engagement surfaces are much closer to each other than in the past, which reduces the rotational force transmitted to the reversing roller via the torque limit means. The pulsation and secular change are significantly reduced compared to the conventional method, and the effect is that stable differential sheet feeding operation becomes possible over a long period of time.

[Brief explanation of the drawing]

Figure 1 is a schematic side view of a torque limit type paper feeding device.
FIG. 2 is a transmission force versus time characteristic diagram of the torque limit means in a conventional paper feeding device, FIG. 3 is a schematic front view of a paper feeding device according to an embodiment of the present invention, and FIG. 4 is a diagram showing A--A in FIG. A sectional view taken along line A and FIG. 6 is a one-hour characteristic diagram of the transmission force of the torque limit means in the same embodiment device. (Friction member), 1ea, 1ab, 17. a, 17b...
...Pulley, 18a, 18b...Belt, 2
0...Friction plate, 21...Spring, 22...
...stopper, 23...screw. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 11 Exterior 5 t'tb Nii N by 8b Figure 4 0 2 Figure 5 to M , 23 2

Claims (1)

[Claims] Through the cooperation of a paper feeding roller that is rotationally driven in the paper feeding direction and a reversing roller that is rotationally driven in the opposite direction to the paper feeding direction via a torque limit means, the paper 1 is supplied between both openings. A paper feeding device that selectively feeds more than one sheet of paper one by one, wherein the torque limit means includes a first friction member that rotates integrally with the reversing roller, and a friction member that is in frictional relationship with the first friction member. a second friction member which is fitted together and rotationally driven; and the first friction member.
and a means for pressing the friction-retaining surfaces of the second friction member against each other, at least the friction-retaining surface of one of the first and second friction members is made of an acetal copolymer, and the friction-retaining surface of the other is made of an acetal copolymer. A paper feeding device characterized in that at least the frictional retaining surface is made of another resin material.