JPH02209336A - Sheet feeder - Google Patents

Abstract

PURPOSE:To perform sheet conveyance in an optional direction inexpensively in a simple structure by constituting it so as to form a standing wave in an elastic body at a side where conveying force is not required and to form a progressive wave in another elastic body at a side requiring it, respectively. CONSTITUTION:Opening switches 8b, 9b installed in a feeder at the lower side, electric energy being generated at vibrators 2b, 4b is not dissipated at an energy absorbing part 10 and vibration is reflected, thereby forming each standing wave in respective elastic bodies 5b, 6b. Thereby, conveying force is not almost generated and frictional resistance is reduced, so that a sheet conveyance from left to right is smoothly performed. Conversely, when this conveying force is intended to produce in the lower feeder, switches 8a, 9a are opened and the switches 8b, 9b are closed instead, thus it is realizable likewise. In addition, the switch 8a, 9a and the switch 8b, 9b both are closed, and each amplitude of generators 7a, 7b is properly regulated, whereby conveyance in the optional direction depending upon a resultant of the conveying force to be produced in each feeder is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention relates to a sheet feeding device installed in a computer, a copying machine, a facsimile machine, a word processor, a typewriter, and other various machines equipped with a mechanism for feeding sheets. be.

(Background of the Invention) Conventionally, this type of device has been configured to feed the sheet by forming a traveling wave in an elastic body that clamps the sheet, as disclosed in Japanese Patent Laid-Open No. 59-177243. Ta.

Here, we will discuss the second principle of sheet conveyance in the above proposal.
This will be explained using figures.

The sheet 13 is held between the elastic bodies 11 and 12 with appropriate pressure. Progressive bending vibrations (progressive waves) are formed in each of the elastic bodies 11 and 12, and the phase difference between these progressive waves is spatially 180°. The bending vibration of .12 progresses on the sheet 13 side so that each convex portion always faces each other. At this time, if attention is paid to, for example, a mass point with a convex portion on the surface of the elastic body 11, 12, the mass point generally moves in an elliptical orbit. In FIG. 2, regarding the elastic body 11, when the traveling wave moves to the right, the mass point will draw a clockwise elliptical locus as shown in the figure. Therefore, the moving direction of the mass points of the convex portions of the elastic bodies 11 and 12 is opposite to the direction of vibration, and this acts as a force to transport the sheet 13.

On the other hand, in the concave portion, a sheet transporting force is generated in the same direction as the traveling direction, but the pressure is smaller than that in the convex portion, so the frictional force between the sheet 13 and the elastic body 11, 12 is small, and the sheet transporting force is also small. Therefore, the total sheet conveying force acts in the direction opposite to the direction in which the bending vibrations described above proceed.

FIG. 3 shows an example of a device that generates the sheet conveying force as described above, and in the figure, reference numerals 11, 12 and 13 are the aforementioned elastic bodies and sheets. Also, 14-1. 14-2
．． 15-1 (not shown) and 15-2 are the elastic bodies 11.1
A vibrator fixed on 2, 16 a pressing support member, 17-
1. 17-2 is a support side plate, and 18 is a bottom plate.

The elastic body 12 is supported by a bottom plate 18, and the elastic body 11 is supported by a pressing support member 16.

Further, the elastic body 11 presses the sheet 13 with an appropriate force due to the spring properties of the pressing support member 13, and holds the sheet 13 together with the elastic body 12.
By applying a certain frequency voltage to each vibrator 12 and applying vibration, the respective convex portions are always facing each other as described above, so that a sheet conveying force is generated.
The sheet is conveyed in the direction of the arrow in the figure. Note that the arrows in the figure point in both directions, which means that the direction of sheet conveyance can be reversed by switching the direction of vibration.

FIGS. 4 and 5 show an example of a device (only the main parts are shown) in which the vibrating body is realized with a different configuration.

FIG. 4 shows a track-shaped vibrator 19-1. Similarly track-shaped elastic body 20-1.20-2 to which 19-2 is fixed
The structure is such that the sheet 13 is held between the vibrator 19-
1. By applying a frequency voltage to 19-2, elastic body 20-1
．． By forming progressive bending vibration in 20-2,
The point of generating the sheet conveying force is similar to the apparatus shown in FIG. 3 above.

FIG. 5 is a cross-sectional view of the apparatus shown in FIG. 4 as viewed from the sheet feeding direction, and there is a difference in level between the left and right sides. This is the elastic body 20-
1. Since the direction of the sheet transport force is acting in opposite directions on the left and right sides of 20-2, this is to prevent the transport force on the opposite side (the right side in Figure 5) from acting on the sheet 13. be.

By the way, in the conventional apparatus as described above, the structure is such that the sheet can be conveyed only in a certain specific direction. However, in recent years, there has been a great demand for conveying sheets in a plurality of directions in the various mechanical devices described above, and the emergence of devices to meet this demand has been desired.

In view of this point, it can be realized, for example, by preparing a plurality of conventional devices as described above and arranging them so that the transfer force is generated in an arbitrary direction by the combined force of these devices. However, in this case, if you want to transport the sheet using the transport force of only one of the multiple devices, simply stopping the vibration of the unnecessary elastic body of the device will not create a gap between the sheet and the elastic body. A problem arises in that a large frictional resistance is generated and the sheet cannot be conveyed smoothly due to the frictional resistance. In order to solve this problem, it is possible to reduce the frictional resistance by increasing the distance between the opposing elastic bodies in a device that does not require a transfer force, but in this case, the distance can be newly increased. This requires a mechanism, which makes the structure complicated and expensive.

(Object of the Invention) An object of the present invention is to smoothly transport a sheet in the same direction as the direction of the transport force generated in any one of a plurality of elastic bodies using an inexpensive and simple configuration. It is an object of the present invention to provide a seed feeding device that can perform

(Features of the Invention) In order to achieve the above object, the present invention applies a frequency voltage to a vibrator fixed to each of a plurality of elastic bodies to form waves in each elastic body, The sheet is transported by the resultant force of the transport forces generated in each of the elastic bodies. When a sheet transport instruction is given in a direction different from the transport direction of each of the elastic bodies, a traveling wave is formed in each of the elastic bodies. , when a sheet conveyance instruction is given in the same direction as the conveyance force generated in any one of the elastic bodies,
The other elastic bodies are equipped with a wave formation control means that forms standing waves, and the elastic bodies that do not require transfer force form standing waves to reduce the transfer force to zero, and It is characterized in that unnecessary frictional resistance between the elastic body and the sheet is reduced.

(Embodiments of the Invention) Hereinafter, the present invention will be described in detail based on illustrated embodiments.

FIG. 1 shows an embodiment of the present invention, in which la, 2
a, 3a, 4a are vibrators made of piezoelectric elements, 5a, 6a
7a is an oscillator that applies a frequency voltage to the electric vibrators 18 to 4a, 8a and 9a are switches, and 10a is an energy absorption section.

The vibrators 1a and 2a are fixed to an elastic body 5a with an adhesive or the like. Similarly, the vibrators 3a and 4a are fixed to the elastic body 6a with adhesive or the like. Further, the elastic bodies 5a and 68 are held down with appropriate force. In this embodiment, the elastic bodies 5a and 68
is connected to the ground circuit as a conductor, and the oscillator 7a
By applying a frequency voltage (alternating current electric field) to the vibrator 1a, vibrations are generated in the elastic bodies 5a and 68. The vibrators 2a and 48 generate electricity as the elastic bodies 5a and 68 vibrate. When the switches 8a, 9a are closed, the generated electrical energy is dissipated by the energy absorbing section 10a made of a resistor or the like. Therefore, the vibration becomes a traveling wave without being reflected. When the bending vibration of the elastic bodies 5a and 6a becomes a traveling wave, focusing on one point on the surface, we get
As mentioned above, the trajectory draws an ellipse. Therefore, the outside part of the bend always has a velocity component in the opposite direction to the traveling direction of the traveling wave, and since the sheet is always in contact with the part outside the bend, it has a velocity component in the opposite direction to the traveling direction of the traveling wave. Sent. In FIG. 1, the conveying force is generated from left to right.

Similar operations are performed in 1b to 10b.

In the above configuration, a case will be described in which the sheet is conveyed from left to right in the figure.

It is necessary to apply only the conveying force generated by the device on the upper side of the figure to the sheet. Now, if the oscillator 7b is stopped in order to make the transfer force of the lower device zero, the elastic bodies 5b, 6b
Since the sheet is pressed, a large frictional resistance is generated between the sheet and the elastic bodies 5b and 6b, and smooth conveyance cannot be performed as described above.

Therefore, in this embodiment, the switches 8b and 9b provided in the lower device are opened to allow the energy absorption section 10b to reflect the vibrations without dissipating the electrical energy generated by the vibrators 2b and 4b, and the elastic body 5b , 6b to form standing waves. When a standing wave is formed in this way, almost no transport force is generated and frictional resistance is reduced, so that the sheet can be transported smoothly from left to right.

Conversely, if you want to generate transfer force only in the lower device,
This can be similarly achieved by opening the switches 8a and 9a and closing the switches 8b and 9b.

Furthermore, by closing both switches 8a and 9a and switches 8b and 9b and appropriately adjusting the amplitudes of oscillators 7a and 7b, it is possible to transport in any direction determined by the resultant force of the transport forces generated in each device. becomes.

According to this embodiment, a standing wave is formed in the elastic body on the side that does not require transfer force, and a traveling wave is formed in the elastic body on the side that requires it (by switching). ,
With a simple configuration and low cost, it is possible to convey sheets in any direction.

(Correspondence between the invention and the embodiments) In this embodiment, 5a, 6a, 5b', 6b are the plurality of elastic bodies of the present invention, oscillators 7a, 7b, switch 8a,
8b, 9a, 9b, the energy absorbing section 10a, and the fob correspond to waveform control means, respectively.

(Modification) In this embodiment, only unidirectional feeding is shown, but bidirectional feeding is possible with the following configuration.

(1) By switching the circuit, that is, by replacing the oscillator and the energy absorbing section, it is also possible to send in the opposite direction.

(2) An elastic body is provided for each axis (upper and lower devices) in which the direction of the traveling wave is opposite, and bidirectional feeding is performed.

In this case, when sending in a certain direction, a standing wave is formed in one of the elastic bodies.

(Effects of the Invention) As explained above, according to the present invention, a standing wave is formed in an elastic body that does not require a transport force, and the transport force is reduced to zero, and the elastic body that is no longer required Since the frictional resistance between the elastic body and the sheet is reduced, the sheet can be conveyed in the same direction as the conveying force generated in any one of the plurality of elastic bodies at an inexpensive and simple configuration. This allows the process to be carried out smoothly.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a diagram for explaining the principle of sheet conveyance in this type of device,
FIG. 3 is a perspective view showing a configuration example of a conventional device, FIG. 4 is a perspective view similarly showing a configuration example of another conventional device, and FIG. 5 is a sectional view taken from the sheet feeding direction of FIG. 4. la, lb, 2a, 2b, 3a, 3b, 4a. 4b... vibrator, 5a, 5b, 6a, 6b...
...Elastic body, 7a, 7b... = Oscillator, 8a, 8
b, 9a9b...Switch, 10a, 10b・
...Energy absorption section.

Claims (1)

[Claims] (1) A frequency voltage is applied to a plurality of elastic bodies arranged so as to generate sheet transport forces in different directions by forming traveling waves, and to vibrators fixed to each of the plurality of elastic bodies. and forming waves in each of the elastic bodies, the sheet is conveyed by the resultant force of the conveying force generated in each of the elastic bodies, and the sheet is conveyed in a direction different from the conveying direction of each of the elastic bodies. If a traveling wave is formed in each elastic body, and if a sheet conveyance instruction is given in the same direction as the conveying force generated in one of the elastic bodies, a traveling wave is formed in the other elastic bodies. A sheet feeding device comprising a wave formation control means for forming a standing wave.