JPH0343172B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a paper feeding device in a copying machine.

For example, copying machines that use copy paper cut into predetermined sizes, such as B4 and B5, use paper cassettes to facilitate the exchange of copy paper of different sizes.

FIG. 1 shows an example of a conventional paper feeding device in such a copying machine. In this apparatus, a paper cassette 1 is detachably loaded into a copying machine main body (not shown). A paper mounting plate 3 is provided inside the main body 2 of the paper cassette 1. Both rear ends of the paper loading plate 3 are loosely fitted into holes (not shown) formed in the side wall of the paper cassette body 2. As a result, the paper mounting plate 3 can freely rotate in the vertical direction around its rear portion. Paper holding members 5 each having a claw 4 at the tip are provided on both sides of the paper mounting plate 3. The paper holding member 5 has a pin 6
It is rotatably attached to the side wall of the paper cassette main body 2 via. The copy paper 7 is placed on the upper surface of the paper placement plate 5, and is set by pressing both edges of the copy paper with the claws 4.

When the paper cassette 1 containing copy paper 7 is loaded into the copying machine main body, an arm 8 provided inside the copying machine main body enters into an opening 9 formed in the bottom plate of the paper cassette main body 2. Arm 8 has pin 10
It is rotatably provided via a spring 11, and is biased counterclockwise by a spring 11. Therefore, the arm 8 that has entered the opening 9 pushes up the paper placement plate 3. As a result, the copy paper 7 is pressed against the feed roller 12 provided within the main body of the copying machine, and loading of the paper cassette 1 is completed.

When copying with this copying machine, a start button (not shown) is pressed. Then feed roller 1
2 rotates in the direction of the arrow, and the top layer of copy paper 7 is sent out from the paper cassette 1. Double feeding of the copy paper 7 is prevented by the claws 4 pressing down on both edges of the copy paper 7. The copy paper 7 sent out from the paper cassette 1 is sent to a recording section (not shown) via a paper guide 13, where it is copied.

By the way, such a conventional paper feeding device requires parts such as a paper mounting plate 3, a paper holding member 5, an arm 8, and a spring 11. Therefore, such a device has a large number of parts, has a complicated structure, and is expensive. Further, in such an apparatus, since the copy paper 7 is fed by the contact friction force of the feed roller 12, it is necessary to increase the contact friction force to some extent. Therefore, in such an apparatus, although the copy paper 7 is brought into relatively strong pressure contact with the feed roller 12, it has the disadvantage that double feeding of the copy paper 7 tends to occur.

Further, some conventional large-sized copying machines are equipped with a paper feeding device as shown in FIG. In this device, a paper mounting plate 22 is provided inside a frame 21 so as to be vertically movable. Paper placement plate 2
Brackets 23 are provided on both sides of 2, and rollers 24 are provided on each of these brackets 23, respectively. The roller 24 is guided by a U-shaped rail 25 provided on the frame 21, and is configured to move up and down while rotating. One end of a wire 26 is connected to the bracket 23. The other end of the wire 26 is connected to a pulley 27 provided at the top of the frame 21.
The pulley 28 provided at the bottom of the frame 21
is wrapped around. The lower pulley 28 is biased in the direction of the arrow by a spring (not shown). As a result, the paper loading plate 22 is urged upward, and the copying paper 29 placed on its upper surface is brought into pressure contact with the feed roller 30. A fixing member 32 and a feed roller 33 pressed against the fixing member 32 are provided in the middle of the paper guide 31.

When copying with this copying machine, when a start button (not shown) is pressed, both the feed roller 30 and the feed roller 33 rotate in the direction of the arrow.
As the feed roller 30 rotates, the uppermost layer of the copy paper 29 placed on the paper placement plate 22 is fed out. This sent out copy paper 29
enters between the fixed member 32 and the feed roller 33, and is sent to a recording section (not shown) by the rotation of the feed roller 33, where it is copied. feed roller 3
When two or more sheets of copy paper 29 are sent out due to 0, the copy paper 29 other than the top layer is stopped by the action of the fixing member 32, thereby preventing double feeding.

However, such a conventional paper feeding device requires a mechanism for vertically moving the paper loading plate 22 and a mechanism for preventing double feeding of the copy sheets 29. Therefore, such a device has a considerably large number of parts, has a complicated structure, and is expensive.

The present invention has been made in view of the above circumstances, and provides a paper feeding device that has a small number of parts, has a simple configuration, can reduce costs, and can reliably prevent double feeding of paper. The purpose is to provide

In the present invention, the paper cassette is formed into a simple box-like shape with an inclined surface on the paper feeding side, and at least a part of the inclined surface is made into a high friction surface. An impeller with blades made of thin elastic material is rotated at high speed and hits the top layer of paper stored in the paper cassette while elastically deforming, thereby loading the paper one sheet at a time from the top layer to the bottom layer in the paper cassette. The material is fed out while being pressed against a high friction surface. This achieves the above-mentioned objective.

The present invention will be explained in detail with reference to Examples below.

FIG. 3 shows the main parts of a paper feeding device in one embodiment of the present invention, and FIG. 4 shows a cross section taken along the line -- in FIG.

In this apparatus, a paper cassette 41 is detachably loaded into a copying machine main body (not shown). The paper cassette 41 consists of a cassette main body 43 which is simply a box with an inclined surface 42 whose paper feeding side is appropriately inclined, and a sheet-like friction member 44 embedded in most of the inclined surface 42. The friction member 44 is made of rubber, felt, cork, etc., and its surface is flush with the inclined surface 42. Copy paper 45 is placed on the upper surface of the bottom plate of the cassette body 43. A shaft 46 is rotatably provided at a predetermined location within the main body of the copying machine, and a blade body (impeller) 47 is mounted on the shaft 46.
is provided. As shown in FIG. 5, the blade body 47 has a cylindrical portion 48 fixed to the shaft 46.
Two thin plate-like blades 49 are provided on the outer periphery of the cylindrical portion 48 and protrude in the radial direction at two locations separated by 180 degrees, and a blade 49 is provided on the rotation direction side of the tip of the blade 49. It consists of a protrusion 50. The blade body 47 is made of a soft elastic material having a large coefficient of friction, such as silicone rubber. The dimensions of the blade body 47 are as follows: outer diameter D is approximately 72 mm, width L is approximately 20 mm, thickness T of blade 49 is approximately 3 mm, and protrusion amount S of protrusion 50 is approximately 1 mm.
The shaft 46 is operated by a motor (not shown).
It is designed to rotate in the direction of the arrow at about 350 rpm.

When the paper cassette 41 is loaded into the main body of the copying machine in this device, it is placed below the blade 47. In this state, the blade body 47 is located above the center of the copy paper 45, and the trajectory drawn by the tip of the blade 49 touches or slightly bites into the bottom plate of the main body 43 of the paper cassette 41 and the friction member 44. It's summery.

When copying with this copying machine, when a start button (not shown) is pressed, the shaft 46 rotates together with the blade 47 in the direction of the arrow. The blade body 47 is
As shown in FIG. 6, when the protrusion 50 comes into contact with the uppermost copy paper 45, the blade
rotates in the direction of the arrow in a suitably elastically deformed and bent state. Since the blade body 47 rotates at a high speed of about 6 revolutions per second, the two protrusions 50 alternately and continuously strike the top layer of copy paper 45. As a result, the uppermost layer of copy paper 45 is sent out from the paper cassette 41, guided by the friction member 44 on the inclined surface 42, and enters the paper guide 51.
Since the surface of the friction member 44 is flush with the inclined surface 42, the copy paper 45 sent out will not be caught here. The copy paper 45 that has entered the paper guide 51 is temporarily stopped at a register stop (not shown), and is then sent to a recording section (also not shown) at a predetermined timing to be copied.

The protrusion 5 of the blade body 47 rotating at high speed in this way
Since the copy paper 45 is fed out by hitting the copy paper 45 with zero, even if the pressing force of the protrusion 50 against the copy paper 45 is small, sufficient feed can be achieved. By providing fine grooves or irregularities on the surface of the protrusion 50, a larger contact friction force can be obtained, and therefore, even if the pressure contact force is smaller, sufficient delivery can be achieved. Furthermore, since only the top layer of copy paper 45 can be sent out by hitting it with a relatively small force, double feeding hardly occurs under normal conditions.

By the way, if the humidity is high, or if you place, for example, sing paper or an OHP (overhead projector) sheet on top of ordinary white copy paper,
When copying is performed, the sheets tend to come into close contact with each other, which tends to cause double feeding.

If double feeding occurs in this device, two or more copy sheets 45 will be fed onto the friction member 44. At this time, the protrusion 50 of the blade body 47 is rotating so as to contact the friction member 44 or to slightly bite into it. Therefore, as shown in FIGS. 7 and 8, two or more sheets of copy paper 45 are fed out and are pressed against the friction member 44 by the protrusion 50. In other words, the remaining copy sheets, excluding the top sheet of the double-fed copy sheets, are indirectly given a downward force by the blades 49 that are elastically deformed on the inclined surface 42, and are subjected to downward force by the friction member 44. Unable to overcome the frictional force and continue advancing, they are left one after another on this frictional member 44. Therefore, even if three or more copies are fed at once, only the topmost copy paper 45 is finally fed by the action of the blades 49 on the inclined surface 42 and the friction member 44. This will ensure that double feeding is prevented.

The paper feeding side of the paper cassette 41 has an inclined surface 4.
2, and the locus drawn by the tip of the blade 49 touches or slightly bites into the resistance of the cassette body 43. Therefore, the copy paper 45 can be reliably fed to the lowest layer.

Further, since the projection 50 provided at the tip of the blade 49 hits the copy paper 45, the outer diameter D of the blade 47 does not change even if the projection 50 is worn out. Therefore, the copy paper 45 can be fed out well over a long period of time.

In the above embodiment, the blade body 47 having two blades 49 is used, but as shown in FIG.
It is also possible to use one having one blade 49 or one or four or more blades.

Furthermore, in the above embodiment, the friction member 44 is embedded in most of the inclined surface 42 of the paper cassette 41;
It may also be embedded in a part of the copy sheet 45 that is brought into contact with it. Further, without using the friction member 44, fine grooves or unevenness may be provided on the inclined surface 42 to prevent double feeding.

As explained above, according to the present invention, the paper cassette can be a simple box, and the blades made of a thin elastic body can be simply attached to the rotating shaft on the paper cassette, thereby controlling the contact between the paper and the blades. The elastic deformation of the blade portion allows the contact between the paper and the blade to shift from the top layer of paper to the bottom layer without taking any special measures to adjust the height of the top layer of paper as it advances. It can be maintained reliably over time. Therefore, not only is it possible to stably feed out every last sheet of paper stored in the paper cassette, but it is also possible to reduce the number of component parts of the paper feeder.
The configuration becomes simple and costs can be reduced.

Further, the paper cassette is provided with an inclined surface, a portion of which is formed of a high friction surface, so that the blades directly contact not only the top of the bottom plate but also the sheets on the inclined portion. Therefore, even if the elastic blades cause multiple sheets to be fed on the bottom plate, the remaining sheets except the top one of the double-fed sheets will be elastically moved on the slope. A downward force is indirectly applied to the deformed blade, and the blade is unable to overcome the frictional force caused by direct contact with the high-friction surface of the slope and continue to advance. It will be done. Therefore, even if three or more sheets are fed simultaneously, only the topmost sheet will be fed out due to the action of the elastic blades and high-friction surface on this slope. , double feeding can be reliably prevented.

[Brief explanation of drawings]

FIG. 1 is a longitudinal side view showing an example of a conventional paper feeding device, FIG. 2 is a longitudinal side view showing another conventional paper feeding device, and FIG. 3 is a main part of a paper feeding device in an embodiment of the present invention. A plan view showing the parts, Fig. 4 is the - of Fig. 3.
5 is a perspective view of the blade body in the same embodiment; FIGS. 6 and 7 are longitudinal side views taken to explain paper feeding in the same embodiment; FIG. 8 is a longitudinal side view taken along a line; FIG. is an enlarged view of the circular portion in FIG. 7, and FIG. 9 is a perspective view showing another example of the blade body. 41... Paper cassette, 42... Inclined surface, 44
...Friction member, 45...Copy paper, 46...Shaft, 47...Blade body, 49...Blade.

Claims (1)

[Scope of Claims] 1. A paper feeding device that takes out sheets of paper stored in a paper feeding cassette from the paper feeding cassette one by one, the paper feeding cassette comprising: a bottom plate on which the paper is stacked;
a paper exit section provided with a high friction member along the paper conveyance path, an impeller having elastically deformable blades is disposed near the paper exit of the paper feed cassette, and the elastic blades are connected to the impeller. Due to the rotation of the impeller, the elastic blades contact the paper placed on the bottom plate, are elastically deformed, and apply a conveying force to the paper; A paper feeding device characterized by pressing paper on a member and elastically deforming it to apply a conveyance force to the paper.