JPH0336109A - Sheet feed device - 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 Application Field] The present invention relates to a sheet feeder provided in a dividing machine, a copying machine, a facsimile machine, a word processor, a typewriter, and various other machines equipped with a mechanism for feeding sheets. It is related to the device.

[Prior Art] Conventionally, this type of device is configured to send a sheet by forming a traveling wave in a vibrating body that clamps a 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 5 is held between the vibrating bodies 3 and 4 with moderate pressure. Progressive bending vibrations (progressive waves) are formed in each of the vibrating bodies 3.4, and the phase difference between these progressive waves is 180° spatially, so
The bending vibration of each vibrator 3.4 progresses so that the white portion of each vibrator always faces the sheet 5 side. At this time, if we focus on a mass point on the surface of the vibrating body 3.4, for example a white part, the mass point generally moves in an elliptical orbit. In FIG. 2, regarding the vibrating body 3, when the following wave moves to the right, the mass point will draw an elliptical locus around the special training as shown in the figure. Therefore, the moving direction of the mass points of the convex portions of both the vibrating bodies 3 and 4 is opposite to the direction of vibration, and this acts as a force for transporting the sheet 5.

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 5 and the vibrating bodies 3 and 4 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 for generating the sheet conveying force as described above, and in the figure, 3.4 and 5 are the vibrating body and sheet described above. 6.7 is the vibrating body 3.4
An electrical element fixed on the top, 8 a pressing support member, 9-1.
9-2 is a supporting side plate, and 10 is a bottom plate.

The vibrating body 4 is supported by a bottom plate 10, and the vibrating body 3 is supported by a pressing support member 8. Further, the vibrating body 3 presses the sheet 5 with an appropriate force due to the spring properties of the pressing support member 8, and holds the sheet 5 together with the vibrating body 4.

By applying a certain frequency voltage to each piezoelectric element and applying vibration to the vibrating body 3.4, the convex portions are always opposed to each other as described above, so that a sheet conveying force is generated. , the sheet is transported 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.

In addition, a large number of slits S are formed on the sheet pressing surface side of the vibrating body 3.4 over the entire circumference, and comb-like vibrating pieces 3a, 4a are formed.
is provided to lower the neutral plane of vibration, increase the feed direction component of the aforementioned elliptical motion, and increase sheet conveyance speed.

FIG. 4 is a cross-sectional view of the vibrating body 3.4 and the sheet 5 shown in FIG. 3, viewed from the sheet feeding direction, and shows a step difference on the left and right sides.

This is because the direction of the sheet transport force is acting in opposite directions on the left and right sides of the vibrating body 3.4, so the transport force on the opposite side (the right side in Figure 4) should not be applied to the sheet 5. It's for a reason.

[Problems to be Solved by the Invention] In the conventional sheet feeding device, the only part where the sheet is pressed is the straight part on the left side of the vibrating body shown in FIG. When the sheet is fed a predetermined amount and printed by a print head, etc., the holding force of the sheet is applied to a small area, so if an external force is applied to the sheet, the sheet will tilt, and if the sheet is conveyed again after printing is completed, it will become skewed. There were times when I did.

SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet feeding device that can obtain a sufficient sheet holding force by a vibrating body even when sheet conveyance is stopped.

[Means for Solving the Problems] The gist of the present invention is to have a vibrating body excited by electric-mechanical energy converting means so as to generate progressive vibration waves; In a sheet feeding device configured such that the vibrating body applies a transporting force to the sheet being pressed against the surface of the vibrating body, the vibrating body includes a ring having at least a pair of linear portions that press the sheet along the sheet conveying direction. A sheet feeding device characterized in that one of the sheet pressing surfaces of the linear portion has a comb-teeth shape consisting of a plurality of vibrating pieces formed by a plurality of slits.

[Function] In the sheet feeding device having the above-mentioned configuration, among the two straight parts that press the sheet and apply a transporting force, the straight part where no vibrating piece is provided causes a squeezing effect and the straight part where the vibrating piece is provided. A sheet conveying force is generated in the same direction.

[Example] Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is a perspective view of a vibrating body showing an embodiment of the present invention, and shows a track-shaped vibrating body. 1 is a piezoelectric element, 2
is a vibrating body. On the surface of the left straight part of the vibrating body 2,
In order to increase the feeding speed of the sheet a, a plurality of slits S are formed and a plurality of vibrating pieces 2a are provided.

On the other hand, no slit is provided on the surface of the right straight section of the vibrating body 2, and the thickness is made equal to that of the left straight section. Although this example shows only the vibrating body, similar to FIG. 3,
Another vibrating body (not shown) having the same shape is arranged to face the vibrating body and applies a transporting force to the sandwiched sheet. In other words, when a sheet is pressed against the vibrating body 2 to cause an out-of-plane bending traveling wave, a transport force acting in the opposite direction to the traveling direction of the traveling wave acts in the left straight part as before, and a pressing force acts in the right straight part. If it is small, there is no air escape such as a slit, so an air layer is formed between the sheet and the vibrating body, and the squeezing effect causes the transport force to act in the same direction as the traveling wave, that is, in the same direction as the left straight part.

When no traveling waves are generated, for example during printing,
Since the sheet is pressed on both the left and right sides, the area on which the holding force is applied is wider than in the past, making the sheet less likely to tilt even when external force is applied, and even when the transport force is generated again afterwards, it is less likely to skew. .

FIG. 5 shows another embodiment of the present invention, in which a plurality of slits S are formed in one straight section of a rectangular vibrating body 2', and a plurality of vibrating pieces 2°a are provided. In this way, the same effect as in the above-mentioned embodiment is obtained.

[Effects of the Invention] As explained above, according to the present invention, a transport force in the opposite direction to the traveling direction of the traveling wave is generated in the straight part of the vibrating body where the vibrating element is provided, and a slit is generated parallel to this straight part. In a straight section where no pressure is provided, a transfer force is generated in the same direction as the above-mentioned transfer force due to the squeeze effect, and when the sheet is not driven, for example, during printing, the sheet can be pressed over a wider area than before, and the sheet is The sheet is less likely to tilt even when an external force is applied, and it is possible to prevent the sheet from being skewed when the sheet is transported again.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2 is a diagram showing the principle of sheet conveyance, Fig. 3 is a perspective view showing a conventional sheet feeding device, and Fig. 4 is the main part of Fig. 3. FIG. 5 is a sectional view of FIG. 5 as viewed from the sheet feeding direction, and FIG. 5 is a perspective view showing another embodiment of the present invention. 11', 6.7... Piezoelectric element 22°, 3.4... Vibrating body 2a, 2°a, 3a, 4a... Vibrating piece 5... Sheet S... Slit and 4 others Figure 0 Figure

Claims (1)

[Scope of Claims] 1. A vibrating body excited by an electro-mechanical energy conversion means to generate a progressive vibration wave, and a force transferred by the vibrating body to a sheet pressed against the surface of the vibrating body. In a sheet feeding device configured to give 1. A sheet feeding device characterized in that a comb-like shape is formed of a plurality of vibrating pieces formed by a plurality of slits.