JPH0519249U - Paper feeder - Google Patents

Abstract

(57) [Summary] [Purpose] When inserting and removing a paper feed cassette in which the leading edge of the stacked sheets is pushed up by the cassette bottom plate and takes a floating posture from the top of the cassette, To avoid the problem of interference with the paper feed roller without using a half-moon roller. [Structure] A paper pressing member 7 for pressing a stack of papers P pushed up by a cassette bottom plate 3 with a presser pawl 7a is attached to paper width regulation guides 2, 2 provided on both sides of a paper feeding cassette 1 so as to be movable up and down. When the front end portion Pa of the cassette-stacked paper P passes under the lower surface of the paper feed roller 9, the paper pressing member 7 is placed above the main body paper feed opening 8 into which the paper feeding device 1 is inserted.
The cam 10 is provided so as to come into contact with the protrusion 7b and temporarily lower the pressing member 7.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a paper feeding device for feeding paper to an image forming apparatus such as a copying machine, a facsimile, and a printer.

[0002]

[Prior Art]

 FIG. 3 shows an example of conventional cassette sheet feeding for the image forming apparatus. In this paper feeding device, the paper feeding cassette 11 is fed to the paper feeding port 14 on the main body side in a predetermined paper feeding state with the paper P stacked on the cassette bottom plate 13 which is provided up and down around the support shaft 12 at the bottom. When it is inserted to the position, the lever 15 which is swingably attached to the bottom surface side of the main body feed port 14 is biased by the feed spring 16 and is pushed to the lower surface of the cassette bottom plate 13 through the notch 11a at the front end of the cassette. The leading edge Pa of the stacked sheets P which are brought into contact with each other and pushed up by the cassette bottom plate 13 is set in a sheet feeding standby state by being pressed by a sheet feeding roller 17 provided above the main body sheet feeding port 14. Is becoming Then, when the paper feed roller 17 is rotated once from this standby state, the stacked paper P is picked up one by one from the surface layer side in contact with the paper feed roller 17 and automatically fed to the image forming unit.

In this type of paper feeding device, when the front end of the paper feeding cassette 11 is inserted near the paper feeding position of the main body paper feeding port 14, the stacked paper P is urged upward by the paper feeding spring 16. Since the cassette bottom plate 13 is pushed up, the leading end portion Pa of the cassette bottom plate 13 is lifted from the upper surface of the cassette. Therefore, when the paper feeding cassette 11 is inserted and removed, the paper leading end portion Pa collides with the lower surface of the paper feeding roller 17. This may interfere with the insertion / removal operation.

Therefore, in the case of the conventional apparatus, a half-moon roller partially cut out on the lower surface side as shown in the figure is used as the paper feeding roller 17, and the paper leading end portion Pa that is floated from the paper feeding cassette 11 is used. Measures are taken to avoid interference.

[0005]

[Problems to be solved by the device]

 However, when a half-moon roller is used as the paper feed roller 17, the rotation stop phase of the paper feed roller 17 is controlled so that the cutout surface 17a of the paper feed roller 17 maintains a positional relationship where the cutout surface 17a faces the stacked paper P when the paper feed is started. It has been pointed out that there is a problem that the positioning means (solenoid) and the mechanical parts accompanying it must be incorporated into the main body side for that purpose.

In view of the above technical problems, the present invention can cause interference between the paper feed roller and the cassette stacking paper even if a normal circular roller is used for the paper feed roller on the main body side. It is an object of the present invention to provide an improved sheet feeding device that eliminates the above problem.

[0007]

[Means for Solving the Problems]

 In the paper feeding device according to the present invention, as means for achieving the above object, the paper width regulating guides provided on both sides of the paper feeding cassette are capable of vertically moving the paper pressing member for pressing the stacking paper pushed up by the cassette bottom plate. On the other hand, when the front end of the cassette-loaded paper passes through the lower surface of the paper feed roller, it abuts against the above-mentioned paper presser member at the upper part of the main body paper feed port where the paper feed cassette is inserted. A cam is provided to temporarily lower the.

[0008]

[Action]

 With this configuration, even if the leading edge of the stack of paper is pushed up by the cassette bottom plate and floats above the upper surface of the cassette, the leading edge of the paper roll will be When passing through the lower surface, the paper pressing member that comes in contact with the cam on the main unit and is lowered is forced to push it down into the paper feeding cassette. It does not interfere with the stacked sheets.

[0009]

【Example】

 Hereinafter, the embodiment shown in FIGS. 1 and 2 will be described.

In FIG. 1, reference numeral 1 denotes a paper feed cassette for accommodating and accommodating paper P having a desired paper feed size therein, and in this case, a rectangular box body having no notches in a bottom wall portion and a peripheral wall portion. It is formed by. This paper feed cassette 1 is provided with a pair of left and right paper width control guides 2 and 2 for restricting the paper width of the stacking paper P on both sides of the front end that contacts the paper feed side, and between the paper width control guides 2 and 2. Is provided with a cassette bottom plate 3.

The cassette bottom plate 3 has a base end portion pinned to the cassette bottom portion by a support shaft 4, and a tip end portion that is close to the cassette front wall 1a is attached to the cassette bottom surface so as to be undulating. A paper feed spring (coil spring) 5 is interposed between the lower surface of the leading end portion and the bottom surface of the cassette to urge the paper sheet P upward, and the leading end portion Pa of the paper P stacked thereon is pushed up to float from the upper surface of the cassette. It is responsible for

On the outer side surfaces of the pair of paper width regulation guides 2, 2, a paper pressing member 7 has its base end portion pinned to a guide middle portion by a support shaft 6, and is vertically moved around the support shaft 6. It is movably attached. Each sheet pressing member 7 has a pressing claw 7a which is bent inward at the upper end of the leading end of the sheet width regulating guide 2. The pressing claw 7a extends upward on the side of the support shaft 6 connected to the pressing claw 7a. The projection 7b that is projected to the center is integrally formed. The holding claw 7a has a lower surface to which the upper edge of the paper P stacked on the cassette bottom plate 3 is locked, and serves to press the leading edge Pa of the paper downward from both sides. The projection 7b is brought into contact with a cam on the main body side, which will be described later, when the paper cassette 1 is inserted into or removed from the main body paper feed port 8 to displace the paper pressing member 7 downwardly along the cam shape. It will play the role of Kamfroy.

On the other hand, when the paper feed cassette 1 is inserted up to a predetermined paper feed position above the main body paper feed opening 8 into which the paper feed cassette 1 is inserted, the front end portion Pa of the cassette stack paper P is placed on the lower surface thereof. A paper feed roller 9 that is pressed by is provided, and a pair of left and right cams 10 and 10 are provided on the front side of the paper feed roller 9 at intervals corresponding to the paper width regulation guides 2 and 2 of the paper feed cassette 1. Has been. The cams 10 and 10 each have a cam surface 10a as shown in FIG. 1B when the front end portion Pa of the cassette-loaded paper P passes through the lower surface of the paper feed roller 9 when the paper feed cassette 1 is inserted or removed. The projection 7b of the paper pressing member 7 comes into contact with the above, and the paper pressing member 7 is temporarily lowered together with the pressing claw 7a that presses the front end portion Pa of the cassette stacked paper P, so that the installation place and the cam surface 10a are not moved. The shape and is selected.

With the sheet feeding device configured as described above, even when the leading end portion Pa of the stacked sheets P is pushed up by the cassette bottom plate 3 and floats above the upper surface of the cassette when the sheet feeding cassette 1 is inserted, the leading edge of the sheet is fed. When the portion Pa reaches the vicinity of the paper feed roller 9, the projection 7b comes into contact with the cam 10 on the main body side, and the paper pressing member 7 is lowered. Since it is forcibly pushed down, the collision between the paper front end portion Pa and the paper feed roller 9 is avoided. Then, as shown in FIG. 1A, when the projection 7b of the paper pressing member 7 has passed over the cam surface 10a, the constraint of the stacked paper P is released, the leading edge Pa is re-floated, and the surface layer is fed. The roller 9 is set in the paper feed standby state in which it is pressed against the lower surface of the roller 9.

Further, when the paper feed cassette 1 is removed from the paper feed standby state, the leading end portion Pa of the stacked paper P is fed as shown in FIG. Since the leading end portion Pa of the sheet escapes from the lower surface of the sheet feeding roller 1 in a state where the sheet is separated from the sheet roller 9 and a gap is formed therebetween, mutual interference is also avoided.

As described above, in the present paper feeding device, when the paper feeding cassette 1 is inserted or removed, the leading end portion Pa of the cassette loaded paper P is automatically placed in the cassette just when the paper feeding cassette 9 passes through the lower surface of the paper feeding roller 9. Since it can be pushed down, there is no risk of interference with the paper feed roller 9. Therefore, a circular roller can be used as the paper feed roller 9 as shown in the figure, and the control of the rotation stop phase required when using the half-moon roller and the positioning means therefor are unnecessary.

In the paper feeding device according to the present invention, the paper pressing member 7 attached to the paper width regulating guides 2 and 2 for regulating the paper width of the stacked paper P is provided above the main body paper feeding port 8 at a corresponding position. Since the lowering operation is performed by the cams 10 and 10, the width of the paper fed to the cassette can be easily changed only by changing the interval between the cams 10 and 10 as shown by the chain double-dashed line in FIG. You will be able to deal with it.

[0018]

[Effect of the device]

 As described above, in the paper feeding device of the present invention, the paper pressing member attached to the paper width regulation guide of the paper feeding cassette and the cam provided on the upper portion of the main body paper feeding port cooperate to feed the paper loaded in the cassette. When the leading edge of the paper passes under the lower surface of the paper feed roller, it is automatically pushed down into the cassette. It is possible to avoid mutual interference in, and to extend the control of the rotation stop phase required when using the meniscus roller and the positioning means therefor.

[Brief description of drawings]

1A and 1B show an embodiment of a sheet feeding device, FIG. 1A is a sectional view of a main part of the apparatus, and FIG.

FIG. 2 is an exploded perspective view of the paper feeding device of FIG.

FIG. 3 is a cross-sectional view of an essential part of a device showing a conventional example of a paper feeding device.

[Explanation of symbols]

 P Paper Pa Paper leading end 1 Paper feed cassette 1a Front wall 2 Paper width regulation guide 3 Cassette bottom plate 4 Support shaft 5 Feed spring (coil spring) 6 Support shaft 7 Paper pressing member 7a Pressing claw 7b Protrusion 8 Main body paper feeding port 9 Feed Paper roller (circular roller) 10 Cam 10a Cam surface

Claims (1)

[Scope of utility model registration request] 1. A paper width regulating guide provided on both sides of the paper feed cassette is provided with a paper pressing member for pressing the stacked paper pushed up by the cassette bottom plate so as to be movable up and down, and at the main body paper feed port into which the paper feed cassette is inserted. A paper feeding device, characterized in that a cam is provided at an upper portion thereof, which abuts against the above-mentioned paper pressing member when the front end of the cassette-loaded paper passes through the lower surface of the paper feeding roller and temporarily lowers the pressing member. apparatus.