JPS6392528A - Cut sheet feeder - Google Patents

Abstract

PURPOSE:To stabilize the separating and feeding operation of a sheet by bringing said sheet into pressure contact with a paper feed roller by an elastic means of a spring, etc. the fulcrum of which is the shaft of said paper feed roller, and making right and left pressure contacting force applied to said sheet uniform. CONSTITUTION:Elastic means 20, 20 for bringing a sheet 6 into pressure contact with paper feed rollers 2, 2 are stretchedly provided with the shaft 12 of the paper feed rollers as the fulcrum. At the same time, a gap S for absorbing the shape error of a placing board is provided in between the placing board 4 on which a layer of sheets are placed and the bottom end connecting parts of the springs 20, 20, i.e., sheet width guide members 7, 7. Thereby, right and left pressure contacting forces for the sheet 6 toward the paper feed rollers 2, 2 are determined by the spring forces of the springs 20, 20. Accordingly, the right and left pressure contacting forces are not affected by the shape error of the placing board 4 and always made uniform right and left, efficiently preventing the skew and jam of a sheet caused by the unbalance between right and left pressure contacting forces.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a cut sheet feeder that automatically feeds cut sheets in a recording device such as a printer.

[Prior art]

A cut sheet feeder is a device that stacks sheets (recording media such as paper or thin plastic plates) that have been cut to a predetermined size, and automatically feeds these sheets one by one to a recording unit, etc., and is used for printers, etc. Widely used in various recording devices such as copying machines.

In this cut sheet feeder, a guide member and a separating member with a sheet width of one width are mounted so as to be movable in the sheet width direction with respect to a sheet stacking plate, and a paper feed roller is movable in the sheet middle direction together with a sheet guide member. A similar structure has been proposed.

The stacking plate holds the sheet in pressure contact with the paper feed roller, and is generally swingably supported by the case.

On the other hand, the separating member separates the sheets one by one while forming a loop at the leading edge of the sheet when feeding, and the claws at the leading edge are constantly engaged with both sides of the leading edge of the upper surface of the sheet stack. It is supported so that it can swing.

The prior art will be specifically explained below with reference to FIGS. 6 to 12.

FIG. 6 illustrates a longitudinal section of a prior art sheet feeder.

In FIG. 6, a paper feed roller 2 is rotatably and operably supported by a case (or chassis) 1.

The stacking plate 4 is urged toward the paper feed roller 2 by a spring 5, and the layer of canted sheets 6 (FIGS. 10 and 11) is held under pressure between the stacking plate and the paper feeding roller. It looks like this.

7 and 8 show a plane and a cross section of the loading plate 4. FIG.

In the following description, the cut sheet feeder has a substantially symmetrical structure, and corresponding parts on the left and right sides are indicated by the same numbers.

A pair of left and right sheet width guide members 7.7 are mounted on the stacking plate 4 so as to be movable in the sheet width direction, and a separating member 8.8 is swingably supported on each sheet width guide member 7.7. .

A separation claw 9.9 is formed at the tip of each separation member 8.8 for separating the sheets 6 one by one from the top layer during paper feeding.

Each sheet width guide member 7.7 is formed with vertical guide surfaces 10, 10 facing each other to regulate the side edges of the sheet 6 to determine the left and right positions.

A total of two paper feed rollers 2 are provided on the left and right sides, and each of them is provided so as to be movable in the middle direction of the sheet together with the left and right sheet width guide members 7.7.

FIG. 9 shows a partial plan view of the paper feed roller 2 and the sheet width guide member 7, and FIG. 10 shows the front side of FIG. 9, respectively.

Each paper feed roller 2 rotates one bit with a paper feed roller shaft 12 supported by the case 1, and is rotated by driving the paper feed roller shaft with a feeder motor (not shown).

Further, each paper feed roller 2 is provided with a protruding bushing portion 13 that fits into the paper feed roller shaft 12, and the bushing portion 13 has a pair of bushings 13 that engage with the vertical wall portions 14, 14 of the sheet width guide member 7. A flange 15.15 is provided. That is, these vertical walls 14.1'4 and the pair of flanges 15
．． 15, as shown in FIGS. 11 and 12, so that they are always engaged regardless of the number of seats loaded.
When the sheet width guide 7.7 is moved in the sheet width direction, each feed roller 2.2 can also be moved by the same amount via the flange.

FIGS. 11 and 12 show side views of main parts when a cut sheet is loaded and when there is no cut sheet.

As shown in FIGS. 11 and 12, each separation member 8 has a notch 16 in a portion corresponding to the bush portion 13.
An integral elastic portion 17 is formed by forming.

As clearly shown in FIGS. 11 and 12, the cut sheet 6 is pressed against the paper feed roller 2 by the loading plate 4 biased by a spring 5 and the sheet guide plate 7 attached to the loading plate 4. The cut sheet 6 is separated and fed by the feeding force generated by this pressing force.

The springs 5 are usually arranged one each at symmetrical positions, and they have the same spring characteristics. Therefore, if the 8I mounting plate 4 has a shape error such as twisting or warping, it is possible to absorb (cancel out) the twisting or warping and press the cut sheet 6 against the paper feed roller 2.2, but the twisting or warping It's anti-JQ) - + Liao II Le dV Nasuna Meno Los Shima Ku Juice 1 - Ka-sized difference in the power of criticism.

As a result, the feeding force applied to the sheet 6 differs between the left and right portions, causing a problem of paper feeding defects such as sheet skew and jamming. [Objective] The object of the present invention is to It is an object of the present invention to provide a cut sheet feeder that can solve the problems of the prior art described above and can stabilize the separation and feeding operation of sheets by equalizing the left and right pressing forces against the sheet.

[Means to achieve the purpose]

The present invention achieves the above object by using a cut sheet feeder configured to press a sheet against a paper feed roller using an elastic means such as a spring having the shaft of the paper feed roller as a fulcrum.

[Example] The present invention will be specifically described below with reference to FIGS. 1 to 5. In addition, in FIGS. 1 to 5, the above-mentioned 6th
Components that are substantially the same as those in FIGS. 1 to 12 are designated by the same numbers, and detailed description thereof will be omitted as appropriate.

FIG. 1 is a partially cutaway side view of a main part of an embodiment of a cut sheet feeder according to the present invention, and FIG. 2 is a partial front view of the right side as viewed from line 1--2 in FIG.

The cut sheet feeder of FIGS. 1 and 2 has an axis 1 of the feed roller 2.2 on both sides of the layer of cut sheets 6.
Tension springs 2G and 20 are connected between the sheet width guide member 7.7 and the sheet width guide member 7.7, and the spring force of the tension springs urges the left and right sheet width guide members 7.7 and the stacking plate 4 upward. The upper layer of cut sheets 6 is pressed against each feed roller 21.2.

That is, in this embodiment, instead of the spring 5 in FIGS. 11 and 12, an elastic means (spring 20.20) having the shaft 12 of the paper feed roller 2.2 as a fulcrum is used to move the sheet 6 onto the paper feed roller. 2. The other parts are substantially the same as the conventional structure shown in Figs. 6 to 12, and corresponding parts are indicated by the same numbers and detailed explanations thereof are omitted. do.

1 and 2, the spring 20.2
The lower end of the sheet width guide member 7.7 is engaged with a pin 21.21 provided on a sheet width guide member 7.7 which is movable in the sheet width direction relative to the stacking plate 4.

Further, the paper feed roller 2.2 rotates integrally with the shaft 12, but is mounted so as to be slidable in the axial direction; The bushing 13.13 is provided with an extension 22 as shown in FIG.

The upper end of said spring 20.20 is thus engaged in an extension 22.22 of said bush 13.13. In this way, each spring 20.20 for pressing the seat 6 is
The paper feed roller 2.2 is moved around the shaft 12 of the paper feed roller 2.2 as a fulcrum.
．． 2 and the sheet width guide member 7.7 so as to be movable in the seat direction.

In addition, the sliding fitting portion 23.23 between the stacking plate 4 and the sheet width guide member 7.7 absorbs shape errors such as twisting and warping of the stacking plate, and absorbs shape errors such as twisting and warping of the stacking plate, and feeds sheets to the left and right paper feed rollers 2.2. A fitting gap or play S (FIG. 1) is provided that does not affect the pressure contact force.

According to the embodiment described above with reference to FIGS. 1 and 2, the elastic means (tension spring) 20.20 for pressing the sheet 6 against the paper feed roller 2.2 is pivoted around the shaft 12 of the paper feed roller 2.2. At the same time, a gap S was provided between the stacking plate 4 on which the sheet layer was placed and the lower end connection part of the spring 20.20 (sheet width guide member 7.7) to absorb the shape error of the stacking plate. , sheet 6 to paper feed roller 2.2
The left and right pressure contact forces are determined by the spring force of each spring 20.20.

Therefore, the pressure contact force on the left and right sides can be made equal to the right and left sides without being affected by the shape error of the loading plate 4, thereby effectively preventing the sheet 6 from skewing or jamming due to the left-right unbalance of the pressure contact force. I was able to do that.

FIG. 3 is a front view of one side of a main part of a second embodiment of the cut sheet feeder according to the present invention, and FIG. 4 is a front view of the main part of one side of the second embodiment of the cut sheet feeder according to the present invention. 7 is integrally formed with an extension portion or roof portion 24.24 extending upwardly to cover the upper part of the paper feed roller 2.2, and on both sides of the layer of cut sheets 6, the shaft 12 of the paper feed roller 2.2 and A compression spring 25.25 is installed between the extension portion 24.24 and the compression spring 25.25.
The spring force of 25 urges the left and right sheet width guide members 7.7 and stacking plate 4 upwards about the paper feed roller shaft 12, thereby transferring the layer of cut sheets 6 on the upper surface of each sheet width guide member 7.7 to each paper feed roller 2. .2.

That is, in this embodiment, instead of the spring 50 of the conventional structure shown in FIGS. 11 and 12, the shaft 12 of the paper feed roller is used as a fulcrum to urge the extension part 24.24 of the sheet width guide member 7.7 upward. Compression spring (elastic means) 25.25
is installed, and the sheet 6 is pressed into contact with the paper feed roller 2.2 by the compression spring.

In the gR9M driver's neck AFL, the feed pressure roller 12 has an extension 24. which moves in the axial direction together with the paper feed roller 2.2 but does not rotate together with the shaft 12.
A slider 27.27 regulated by 24 guide grooves 26.26 is fitted. Each slider 27.2
7 can be moved in the axial direction by engaging their rectangular cross-section guide portions 28, 28 with the guide grooves 26, 26, but are restricted from rotating.

Further, flanges 29, 29 are provided on both sides of the guide portion 28 of each slider 27 in the axial direction, and engage with the extension portion 24 of the slider 27 so that the slider 27 can move along the shaft 12 together with the sheet width guide member 7. There is.

Each of the sliders 27, 27 is provided with the compression spring 2.
A pedestal 30.30 is provided for receiving the lower ends of 5.25, and between these pedestals and said extension 24.24 said compression spring 25.25 is mounted in compression.

Therefore, the spring force of these compression springs 25.25 urges each sheet width guide member 7.7 and the stacking plate 4 in the direction of arrow P (upward), and the layer of sheets 6 on the stacking plate is fed. It is pressed against roller 2.2.

Furthermore, as in the embodiment of FIGS. 1 and 2, the sliding fitting 23.7 between the stacking plate 4 and the sheet width guide member 7.7.
23 (Fig. 1) is provided with a fitting gap or play S( (Fig. 1) is provided.

The parts of the embodiment shown in FIGS. 3 and 4 other than those described above are substantially the same as the conventional structure shown in FIGS. is omitted.

Also in the second embodiment described above with reference to FIGS. 3 and 4, the elastic means (compression spring) 25.25 for pressing the sheet 6 against the paper feed roller 2.2 is connected to the shaft 12 of the paper feed roller 2.2. The shape of the stacking plate 4 is determined by the engagement gap S provided between the stacking plate 4 on which the sheet is placed and the sheet width guide member 7.7 which is biased by the elastic means 25.25. Since the error is absorbed, the paper feed roller 2.
The pressing force of the seat 6 against the seat 2, that is, the left and right pressing forces of the seat 6 is determined by the spring force of each spring 25, 25.

Therefore, as in the case of the above-mentioned embodiment, even if there is a shape error in the stacking plate 4, the pressing force on the left and right sides of the sheet 6 can be made equal, thereby preventing skew or jamming of the sheet 6 due to an imbalance in the pressing force. I was able to eliminate it.

FIG. 5 is a longitudinal cross-sectional view illustrating a recording apparatus such as a printer incorporating a cut sheet feeder according to the present invention.

In FIG. 5, a platen roller (also used as a sheet feeding roller) 32 is pivotally supported in an exterior (case) 31 of the recording device, and a carriage 34 is movable along a guide shaft 33 installed parallel to the platen roller. Record on top rad 3
5 is mounted, and is configured to be supplied to the circumferential surface of the platen roller 32, backed up, and recorded.

A pinch roller 36 and a paper guide 37 are provided on the circumferential surface of the platen roller 32 to accurately feed the cut sheet 6 to be inserted.

Further, a cut sheet feeder 40 according to the present invention is provided within the exterior 31.

This cut sheet feeder 40 is composed of a paper feed roller 2, a stacking plate 4, a sheet width guide member 7, etc., which have substantially the same structure as that of the previous embodiment. The layer of cut sheets 6 held under pressure during this operation is fed one by one through the paper guide 37 to the recording section on the circumferential surface of the platen roller 32.

However, in the conventional cut sheet feeder, the 11th
As shown in the figure, since the spring 5 for sheet pressure contact is installed between the case 1 and the loading plate 4, a gap of minimum height Ll is required between the case 1 and the loading plate 4, and the case 1 serves as a support point for the spring 5. was also necessary.

1- = L -kZ 1z circle RM /I'
l J+ -, L +'7 L tsu -h
” According to I/1, the height Ll shown in FIG.
This eliminates the need for a gap, and also eliminates the need for the case 1 as a support point for the spring 5.

Therefore, when a cut sheet feeder is installed in a recording apparatus as shown in FIG. 5, the cut sheet feeder according to the present invention can be installed in a space with a smaller height and space than those of the prior art. The height and volume of the entire recording apparatus can be reduced, and the effect of reducing the weight and size of the apparatus has also been achieved.

〔effect〕

As is clear from the above explanation (according to the cut sheet feeder of the present invention, the sheet is pressed against the paper feed roller by an elastic means with the axis of the paper feed roller as a fulcrum), It was possible to eliminate the left-right unbalance of the pressure contact force on the paper feed roller, and furthermore, by reducing the external dimensions of the cut sheet feeder, it was possible to easily integrate it into the recording apparatus.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a main part of a first embodiment of a cut sheet feeder according to the present invention, FIG. 2 is a front view of the right side portion seen from line nn in FIG. 1, and FIG. 3 is a cross-sectional view of a cut sheet feeder according to the present invention. A front view of the right part of the second embodiment of the cut sheet feeder, FIG.
5 is a longitudinal sectional view of a recording device incorporating a cut sheet feeder according to the present invention, FIG. 6 is a longitudinal sectional view of a conventional cut sheet feeder, and FIG. 7 is an upper case of the upper case shown in 6. 8 is a partially sectional side view taken along the line ■-■ in FIG. 7, FIG. 9 is a partial plan view of the paper feed roller and sheet guide member, and FIG. The figure is a partial front view taken from line XX in FIG. 9, FIG.
FIG. 2 is a longitudinal sectional view of the main part of FIG. 11 when no sheet is loaded. 2.--...Paper feed roller, 4.--.
・−・−・8￥Plate, 6・・・−・−−・Cut sheet, 7−・−・・−Sheet middle guide member, 12・・・・・−
・-Axle of paper feed roller, 20.25---1・---11 elastic means, S・---m-gap. Figure 4 Figure 5

Claims (1)

[Claims] (1) A cut sheet feeder characterized in that a sheet is pressed against a paper feed roller by an elastic means having the axis of the paper feed roller as a fulcrum.