JPH0635294B2 - Sheet feeding device - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a sheet supply device that is installed in a recording device such as a printer, a printing machine, and a copying machine, and that can separately supply sheets such as recording sheets to the recording device.

[Prior art]

FIG. 4 shows a general configuration example of a printer equipped with this type of sheet feeding device. In the figure, A is a printer main body, and B is a sheet feeding device attached to this printer. The printer A has a printing section P for sheets such as sheets (not shown).
Platen 1 for backing up and printing element 2
A carriage 3 having the print element 2 mounted thereon and moving in the print digit direction, a paper feed mechanism 4 for stepwise feeding the sheet at the position of the platen 1 in the row direction, and a drive device for the paper feed mechanism 4 ( (Not shown) and drives the print element 2 while moving the carriage 3 in response to a print signal input from an external device such as a computer or an input key to execute printing on a sheet. There is. When the printing of one line is completed, the paper feeding mechanism 4 is operated to stepwise feed the sheet to the next line. Here, the platen 1 is composed of a shaft-shaped stem material positioned in the seat width direction, the surface facing the seat is formed of an elastic material such as rubber, and is fixedly supported by the frame 6 in the casing 5. . A U-shaped paper path 7 is formed around the platen 1, and a sheet is taken in from a paper feed opening 7a at one end of the paper path, printed by a printing section P, and then ejected from a paper ejection opening 7b at the other end. It is supposed to do. Next, the sheet feeding device B will be described. The sheet feeding device B is detachably mountable to the frame 6 of the printer A, and has a mounting machine frame 21, a sheet feeding stacker 22 connected to the sheet feeding port 7a of the printer A, and sheets such as sheets stacked and stored in the sheet feeding stacker ( (Not shown), a sheet feeding rotating member that engages with the uppermost position, that is, the sheet feeding roller 23, and sheet feeding that guides the sheet fed by the sheet feeding roller 23 to the pressure contact point between the sheet feeding roller 8 and the pinch roller 9. A path 24, a discharge rotating member arranged near the discharge port 7b of the printer A, that is, a discharge roller 25, and a discharge roller 25 that faces the discharge roller 25 and guides the printed sheet to a discharge stacker 26. And a paper guide 27. The sheet supply device B corresponds to a type in which sheets are separated and supplied one by one by the action of so-called separation claws, and a thickness of one sheet between the leading end of the sheet storage frame and the sheet feeding roller. There is a type in which a gap is provided and the sheets are separated and supplied one by one using this gap, but since the present invention relates to the latter type, such a type will be described with reference to FIG. In the sheet feeding stacker 22 of the sheet feeding apparatus B, a sheet storage frame 31 is formed of a molded body of left and right side plates 31a and 31b and a bottom plate 31c, and a sheet mounting table 32 formed of a plate-shaped body is provided inside the storage frame 31. Is arranged so that it can move up and down. That is, the rear end portion of the sheet mounting table 32 is supported by the bottom plate 31c of the storage frame 31 by the pin 33, and the front end portion is supported so as to be vertically movable around the pin 33, and the bottom plate 31c of the storage frame 31 is supported. A spring 34 arranged between them is biased toward the paper feed roller 23. The paper feed stacker 22 is attached to one of the left and right side plates 31a and 31b of the storage frame 31 so that the slide side plate 35 can be adjusted in the width direction so that sheets such as postcards can be stored in a horizontal position or a vertical position. is there. Further, the paper feed stacker 22 is formed with a protrusion 36 hanging from the bottom plate 31c thereof, and is fitted into a guide groove (not shown) of the apparatus machine frame 21 to be mounted. A locking projection 37 is provided. The left and right side plates 31 of the paper stacker 22 are
A positioning piece 38 having a U-shaped groove 38a extending from a and 31b is fitted to the rotary shaft 23a of the paper feed roller 23,
The positional relationship between the paper feed roller 23 and the paper feed stacker 22, especially the paper feed gap between the rollers at the center and right side of the paper feed roller 23 in the drawing and the tip abutting piece 39 described later is kept constant. . The leading edge abutting piece 39 is formed integrally with the storage frame 31, and at the same time as locking the leading edge of the sheet on the sheet mounting table 32, the topmost one sheet is fed out in cooperation with the sheet feeding roller 23. Thus, a gap corresponding to the thickness of one sheet is formed. In the sheet feeding device B thus formed, the sheet mounting table 32 of the sheet feeding stacker 22 is constantly urged toward the sheet feeding roller 23 by the spring 34. However, at this time, only the uppermost sheet passes through the gap between the leading end abutting piece 39 and the sheet feeding roller 23, and the leading end abutting piece 39 prevents the second and subsequent sheets from advancing. It will be separated one by one
Be delivered.

[Problems to be Solved by the Invention]

However, such a sheet feeding device has the following drawbacks. Since two or more sheet feeding rollers 23 are arranged at a distance in the sheet width direction in order to apply a uniform feeding force in the sheet width direction and obtain stable separation, the two feeding rollers The center of the sheet rises between the two rollers and tends to curl or wavy. This is because there is an air layer between the stacked sheets, which causes the sheet to be pressed from both sides to lift up the intermediate portion, or the sheet is fed to both sides by the sheet feeding roller 23, so that the sheet tends to approach the central portion. Depending on the phenomenon in which the force is generated, in the case of thick paper, plastic sheet, etc., the effect of this curling or waviness phenomenon is large, and the so-called skew in which the fed sheet is inclined frequently occurs, or non-feed or double feed occurs. The curling or waviness phenomenon is large when the stacking amount of the sheets 30 is large as shown in FIG. 6 (a), and the feeding force of the sheet feeding roller 23 is large, so that the sheet 30 is conveyed as shown in FIG. 6 (b). When the stacking amount decreases, the sheet 30 follows the shape of the sheet mounting table 32, and the degree of the sheet 30 decreases, and the sheet feeding roller 2
The feeding power of 3 becomes weak. Therefore, the paper feed separation conditions such as the size of the gap and the pressure contact force between the paper feed roller 23 and the sheet 30 are set as shown in FIG.
If the state is set as the reference, reliable separation cannot be obtained in the state of (b) in the figure, and if it is reversed, reliable separation cannot be expected in the state of (b) in the figure. In particular, if you print on a cardboard sheet such as a postcard with a normal typewriter or printer, and then set it on the paper feed stacker 22 to print on the back side again, the space between the sheets will become larger than expected, and non-feeding will occur. Alternatively, there is a problem that skew frequently occurs and reliable separation / feeding cannot be performed.

[Object of the Invention]

In view of the above problems, the present invention, even for a cardboard sheet such as a postcard, hits the paper feed roller in a substantially uniform posture and state regardless of the number of stacked sheets set in the paper feed stacker. An object of the present invention is to provide a sheet feeding device that can be brought into contact with each other and can be fed to a preset sheet feeding gap in a stable posture, and can stably feed from the first sheet to the last sheet.

[Means for solving problems]

The present invention has been made in order to achieve the above-mentioned object, and a paper feed roller connected to an appropriate drive means and a leading end in the paper feed direction are arranged so as to be vertically movable while facing the paper feed roller. A sheet placing table made of a plate-like body for pressing a sheet placed on the sheet feeding roller into pressure contact with the sheet feeding table, and engaging with the leading edge of the sheet placed on the sheet placing table and the sheet feeding roller; A sheet feeding device provided with a leading end abutting piece provided so as to form a sheet feeding gap for one sheet between the sheets, and the sheets are separated and fed one by one by rotating the sheet feeding roller. The paper feed rollers are arranged at two or more locations in the paper feed width direction with a predetermined distance therebetween, and the paper feed direction is provided at the front end of the sheet mounting table facing at least the inner peripheral edge portion of each paper feed roller. Protruding to A sheet feeding apparatus, characterized in that the formation of the.

[Action]

The above means operate as follows. The projecting portion formed at the tip of the sheet mounting table pushes up the sheets stacked on the sheet mounting table so as to contact at least the inner edge portions of the sheet feeding rollers. Strong engagement is obtained, and a substantially uniform feeding force is obtained by the sheet feeding roller over the entire length in the sheet width direction, and sheet skew can be prevented. Also, when the number of placed sheets is small, the undulation due to the bulge of the sheets between the sheet feeding rollers tends to be smaller than when the number of sheets is large. Since the mounting table has a protrusion protruding in the sheet feeding direction, even if the number of sheets decreases, the sheets are forced to bulge between the sheet feeding rollers, so that the sheets are almost uniform regardless of the number of placed sheets. It is extended in a posture.

【Example】

An embodiment of the sheet feeding device according to the present invention will be described below with reference to FIGS. 1 and 2. As shown in the figure, the paper feed stacker 22 has a paper storage frame 31 formed of left side plates 31a and 31b and a bottom plate 31c, and a sheet mounting table 32 is vertically movable inside the storage frame 31. There is. That is, the rear end portion of the sheet mounting table 32 is rotatably supported by the bottom plate 31c of the storage frame 31 by the pin 33, and the front end portion is supported movably up and down with the pin 33 as a fulcrum, and the storage frame 31 and the bottom plate 31c are supported. Is urged toward the paper feed roller 23 by a spring 34 disposed between Further, the paper feed stacker 22 has a slide side plate 35 on one of the left and right side plates 31a and 31b of the storage frame 31 so that the width direction position thereof can be adjusted so that a cardboard sheet such as a postcard can be stored in a horizontal position or a vertical position. It is movably attached. Further, the paper feed stacker 22 is formed with a protrusion 36 hanging from the side plate 31c thereof, and is fitted into a guide groove (not shown) of the apparatus machine frame 21 to be mounted. At the same time, a hooking protrusion 37 is provided. Further, the paper feed stacker 22 includes left and right side plates 31a, 3
Positioning piece 3 having U-shaped groove 38a extending from 1b
8 is fitted to the rotary shaft 23a of the paper feed roller 23, and the positional relationship between the paper feed roller 23 and the paper feed stacker 22, especially the paper feed gap between the paper feed roller 23 and the tip abutting piece 39 described later. Is kept constant. The leading edge abutting piece 39 is formed integrally with the storage frame 31, and at the same time when the leading edge of the sheet on the sheet mounting table 32 is hooked, the uppermost sheet is fed to the sheet feeding roller 23 at the center and right side of the drawing. A sheet feeding gap corresponding to the thickness of one sheet is formed between the two sheet feeding rollers 23 so as to be fed out in cooperation with the above roller. It is formed only at a position facing substantially the center of the paper feed roller 23. This is because even if the sheet undulates or curls in the width direction, at this position the paper feed roller 23
This is because the swell hardly occurs when it is in contact with, and the non-feeding is prevented by disposing it at this position. As described above, the leading end of the sheet mounting table 32 swings about the rear end of the sheet, and in particular, the sheet mounting table 32 is at the uppermost position as shown in FIG. The bearing position of the pin 33 is set so that the leading edge of the roller 23 abuts on the sheet feeding roller 23 at the position where it abuts on the roller 23, and the leading edge of the pin 33 is set on the sheet feeding roller 23.
The portion facing the peripheral edge 23b is formed in a protruding shape protruding in the sheet feeding direction. That is, as shown in FIG. 1, the leading edge portions 32a and 32b of the sheet mounting table 32 protrude in the sheet feeding direction, and both of them are the sheet feeding roller 23.
It is provided at a position facing the peripheral edge 23b. The projections 32a and 32b are provided on the left and right two paper feed rollers 23 so as to face the peripheral edge portions from the inner center of the respective paper feed rollers 23.
2b prevents an imbalance when the sheet is paid out. Further, as a matter of course, the protrusions 32a and 32b may have a shape which continuously protrudes in the sheet feeding direction between the sheet feeding rollers 23 as shown in FIG. Reference numerals 41 and 42 in FIG.
The accommodated sheet is held between the sheet mounting table 32 and the sheet mounting table 32 which is acted by the spring 34, by the holder piece which is pushed out above. In this case, if it is not necessary to make the paper feed stacker 22 detachable, the mounting position of the paper feed roller 23 and the tip abutting piece 39 is adjusted when the paper feed stacker 22 is assembled and fixed in the machine frame 21. Then, the paper feed gap may be maintained. Further, as shown in FIG. 2, the position adjustment between the tip abutting piece 39 and the paper feed roller 23 is performed by moving the paper feed stacker 22 to the paper feed roller 23 side by the leaf spring guide 44 provided in the apparatus machine frame 21 described above. At the same time, the projections 40 (a pair of left and right shown in the figure) are projected from the paper feed stacker 22 and abutted against the rotary shaft 23a of the paper feed roller 23 to hold the paper feed gap G. It is also possible to do so. In the above-described embodiment, the paper feed rollers 23 are arranged at two or more positions in the paper feed width direction with a predetermined distance therebetween, and at least the inner peripheral edge of each of the paper feed rollers 23 of the sheet mounting table 32 formed of a plate-like body. Since the projecting portions 32a and 32b projecting in the sheet feeding direction are formed at the tip end portion of the position facing the portion 23b, the sheets are forcibly bulged between the sheet feeding rollers even if the number of placed sheets decreases. It is delivered in a substantially uniform posture regardless of the number of placed sheets.

As described above, in the sheet feeding apparatus of the present invention, the sheet feeding rollers are arranged at two or more positions at a predetermined distance in the sheet feeding width direction, and at least the sheet feeding rollers of the sheet mounting table are arranged. By forming a protrusion that protrudes in the paper feed direction at the tip facing the inner peripheral edge, the sheets set in the paper feed stacker are fed in a substantially uniform posture and state regardless of the number of sheets. Since it can be fed to the preset paper feed gap with a stable posture by engaging with the roller,
It has a remarkable effect that it can separate and feed from the first sheet to the last sheet.

[Brief description of drawings]

FIG. 1 is a top view showing a main part configuration of a sheet feeding apparatus according to an embodiment of the present invention, FIG. 2 is a side view of the main part, and FIG. 3 is a sheet mounting table according to another embodiment of the present invention. A plan view of
FIG. 4 is a side sectional view showing a main part of a conventional general printer equipped with a sheet feeding device, FIG. 5 is a schematic view showing a drive system of a conventional general sheet feeding device, and FIG. It is an explanatory view showing a sheet supply state. 22 ... Sheet platform 23 ... Feeding roller 30 ... Feeding stacker 32a, 32b ... Projection 39 ... Tip abutment piece

Claims (1)

[Claims] 1. A paper feed roller connected to an appropriate drive means,
A sheet placing table, which is a plate-like body, is arranged such that its front end in the sheet feeding direction faces the sheet feeding roller and is movable up and down, and presses a sheet placed on the upper surface to the sheet feeding roller. A leading end abutting piece provided so as to engage with a leading edge of the sheet placed on the table and form a sheet feeding gap for the sheet with the sheet feeding roller. In a sheet supply device that separates and supplies the sheets one by one by rotating the paper feed roller, the paper feed rollers are arranged at two or more positions at a predetermined distance in the paper feed width direction, and the sheet is placed. A sheet feeding apparatus, wherein a protrusion protruding in the sheet feeding direction is formed at a tip portion of a position of each of the sheet feeding rollers of the table which faces at least an inner peripheral edge portion.