JPH033825A - Sheet feed device - Google Patents

Abstract

PURPOSE:To prevent last double feeding when thick sheets are supplied and fed by providing high friction sheets at the portions situated below separating claws when side guide members for guiding both side ends of the thick sheets are mounted to the sheet feed device. CONSTITUTION:When common sheets 4a are loaded on loading members 3 and fed, the common sheets 4a are separated and fed in such manner as to get over separating claws 6. When thick sheets 4b are fed, thick sheet side guide members 8 are mounted to the loading members 3. Thus, the thick sheets 4b are separated and fed through the slits of the separating claws 6 with their both sides being guided. Further, in this case, since high friction sheets 9 are positioned below the separating claws 6, the last sheet is brought into pressure- contact with the high friction sheets 9 by the separating claws 6 regardless of the state of a sheet feeding means, and thereby the generation of double last feeding can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a sheet feeding device that separates and feeds a plurality of stacked sheets one by one using a separation claw.

<Prior art> In recording devices such as printers and copying machines, or document reading devices, multiple sheets (recording paper, manuscripts, etc.) are stacked.
Many use a feeding device (so-called cut sheet feeder) for separating and feeding sheets one by one.

There are various types of sheet separation mechanisms for the feeding device, and a typical one uses separation claws. As shown in FIG.
The uppermost sheet 51 is pressed against the feeding roller 54 by pressing the stacking plate 50 with the pressing spring 53, and when this feeding roller applies feeding force to the uppermost sheet I-, the uppermost sheet 51 The sheet i.5] forms a loop between the separating claw 52 and the feeding roller 54, and with its "strength" it overcomes the separating claw 52 and is separated and fed one by one.

Furthermore, when the feeding mechanism is used in a recording device,
After the normal recording is started, the rear end of the sheet 51 comes off the feeding roller 54. Therefore, the sheet 51
When the end of the sheet 1 comes off the feed roller 54, the general feeding load of the sheet 1 changes, and the feeding pitch may be disturbed. Also, in word processors etc., the text may be sent backwards,
Normally, if you reverse feed the sheet that has started feeding sheet 1-,
The trailing edge of the sheet may hit the stationary feeding roller 54, causing a jam.

Therefore, as shown in FIG. 6, the feeding roller 54 has an arc portion 54a that presses against the sheet 51, and an arc portion 54b that does not come into contact with the sheet 51.
After the sheet I 51 is conveyed to the conveyance roller 55 by the arc portion 54a, the roller 54 is rotated by a predetermined amount so that the arc portion 54b faces the sheet 51.

<Problems to be Solved by the Invention> However, in the above-mentioned feeding mechanism, when the sheet 51 is conveyed by the conveying roller 55, the arc portion 54b of the feeding roller 54 faces the sheet 51, and the feeding roller 54 is not in contact with Cito51. Therefore, the sheet 51 is not pressed against the placing plate 50, and as a result, when an attempt is made to feed the second to last sheet 51, the frictional force between the sheets is greater than the frictional force between the sheet 5I and the placing plate 50. This may cause the last sheet to be dragged by the second to last sheet, ie, so-called lath I/double feeding. This was particularly likely to occur when feeding thick seams.

SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet feeding device that can solve the above-mentioned conventional problems and prevent the occurrence of the last double feeding.

<Means for Solving the Problems> A typical means of the present invention for solving the problems described above includes a placing member for placing a sheet, and an uppermost layer of sheets laminated on the placing member. a separating claw having a claw portion that presses the top surface of the sheet I located in the uppermost layer; - a feeding means for applying feeding force to the mounting member;
a thick sheet side guide member having a high friction sheet at a predetermined position, and when the thick sheet side guide member is attached to the mounting member, the high friction sheet I.
is characterized in that it is configured to fit under the claw portion of the separation claw.

<Function> In the above means, when ordinary sheets are stacked on the placing portion ii, the ordinary sheets are separated and fed so as to pass over the separating claws.

In addition, when feeding a thick sheet, attach the thick sheet I, side I, and guide member to the above-mentioned mounting member.

As a result, the thick sheets 1 to 1 to be fed are separated and fed through the slits of the separating claws while being guided by both sites. Furthermore, in this case, since the high-friction sheets 1~ are located under the separation claws, the last seams 1~ are in pressure contact with the high-friction sheets by the separation claws regardless of the state of the feeding means, resulting in a so-called lath I-heavy state. This prevents the occurrence of

<Example> Next, an example of a recording apparatus to which the above-mentioned means is applied will be described.

Fig. 1 is a perspective explanatory view of the sheet 1-feeding device according to this embodiment, Fig. 2 is an explanatory view when feeding a normal sheet I, and Fig. 3 is an explanatory view when feeding a thick sheet. FIG.

First, to explain the general structure of the whole, a mounting plate 3 that is urged upward by a pressing spring 2 is housed inside the frame 1, and a large number of ordinary sheets such as plain paper are placed on this mounting plate 3. 4a is loaded and the feeding roller 5 is rotated in the direction of the arrow in FIG. ing. Further, a side guide member 8 for thick sheets is removably attached to the mounting plate 3, and when feeding the thick sheets 1-4b, the side guide members 8 can be attached to the thick sheets 1-4b. b is configured to be fed to the conveyance roller 7 while being guided by the site guide member 8 at both ends thereof.

A high-friction sheet 1-9 is attached to the side guide member 8, and the lowermost sheet is in pressure contact with the high-friction sheet 9 by the separation claw 6.

Next, to specifically explain the structure of each part, the frame 1 is divided into a left half 1a and a right half 1b, and each time they are slid along the axis 10, they are adjusted in the entire width direction of the seat. is now possible. Further, the above-mentioned placing plate 3 is also housed separately in the left and right frames 1a and 1b, and each placing plate 3 is urged upward by the pressing spring 2, whereby the most common sheets 4a stacked on the placing plate 3 are The upper layer is configured to come into pressure contact with the feeding roller 5. Furthermore, the left and right frame bodies 1
A and lb are provided with ordinary sheet side guides 11 on the outer wall portions thereof, which guide the opposite ends of the ordinary sheet 4a, and are configured to guide the opposite ends of the ordinary sheet 4a to be fed. There is.

Next, as shown in FIG. 1, the feed roller 5 is integrated with the shaft 10 by fitting the protrusion 5a of the roller 5 into the groove 10a formed in the shaft 10 to which the driving force from the motor (not shown) is transmitted. It rotates, but is slidably attached in the thrust direction, and is configured so that it can be set at an appropriate position depending on the width of the seats 1-4a, 4b to be set.

Further, the outer peripheral portion of the feeding roller 5 is made of a high-friction member such as rubber, and has an arc portion 5b and an arc portion 5C having a diameter shorter than the diameter of the arc portion 5b, as shown in FIG. When the feed roller 5 is rotated, the arc portion 5b is in pressure contact with the sheet 4a4b, and the arc portion 5C is in pressure contact with the sheet 4a4a.
, 4b.

Next, the separation claws 6 will be explained. In this embodiment, the separation claws 6 are formed integrally with the frame body 1, and the separation claws 6 are formed integrally with the frame body 1, and each seat 1-4a is
, 4b, and an abutting part 6b against which the leading edge of the sheet abuts, and a slit 6C is formed between the claw part 6a and the abutting part 6b. There is. This slit 6C is formed to approximately half the width of the claw portion 6a, and when the side guide member 8 of the thick sheet 4b is attached and the thick sheet 4b is turned over, the front end of the uppermost thick sheet 4b is formed. Although the corner portion is pressed by the claw portion 6a of the separation claw 6, the front end of the sheet is configured to have a shape and size that allows it to smoothly advance straight in the feeding direction through the slit 6C without hitting the contact portion 6b.

Further, as shown in FIG. 4, the slit 6C has a projected dimension in the traveling direction of the fed sheet, and a projected dimension formed in a direction different from the L+, that is, the claw portion 6a and the abutting portion 6.
It has a distance of 1.2 from Ll, and Ll is larger than Ll. Furthermore, the projected dimension L1 of the sheet l-progressing direction and the thickness Ll of the thick sheet l-4b to be fed.
The vertical projected dimension L2 of the claw portion 6a is smaller than
The thickness is set to be larger than the thickness of the thick sheet 4b, which is 1.3.

Next, the site guide member 8 for the thick sheet 1-4b will be explained. As shown in FIG. When a thick sheet 1-4b is placed on this placing portion 8a, a sheet 4b is placed.
1-' guide portions 8b for guiding both side ends of the guide portion 8b, and high-friction sheaths 1 to 9 made of clarino, cork, or the like are attached to substantially the entire surface of the mounting portion 8a.

The side guide member 8 is configured to be removable on the mounting plate 3 by being placed within the frame 1 and on the mounting plate 3. When this side guide member 8 is mounted on the mounting plate 3, the distance between the left and right site guide portions 8b is set narrower than the distance between the side guides 11 that guide both side ends of the normal sheet 4a, which will be described later. A portion of the high-friction sheath I-9 is located below the separation claw 6.

Next, an explanation will be given of the operation when feeding a sheet using the apparatus configured as described above.

First, when feeding the normal sheet 1-4a, the site guide member 8 is removed as shown in FIG. Set as the first concubine. In this state, when the shaft 8 is rotated in the direction of the arrow in FIG. 2, the arc portion 5b of the feeding roller 5 rotates in pressure contact with the sheet h4a, and a propulsive force is applied to the uppermost sheet t-4a. At this time, since the tip of the sheet 1-4a is in contact with the abutting portion 6b of the separation claw 6, a loop is formed between the separation claw 6 and the feeding roller 5, and when the loop is formed to a certain extent, the sheet 4a The tip of the sheet comes off from the separation claw 6 due to the strength of the driver's movements, and the recording sheet of the top layer) 4a
is fed over the separation claw 6 to the conveyance roller 7.

As described above, after the sheet 4δ is nipped by the conveyance roller 7 driven and rotated by a motor (not shown) and the pinch roller 7a which is in pressure contact with the rollerf and rotates as a result, the sheet 4δ is conveyed to a predetermined recording section etc. by the conveyance rollerf. At this time, the arc portion 5c of the feeding roller 5 faces the sheet 4a and is separated from the sheet 4a.

Next, to explain the case of feeding a thick sheet]・4b, in this case, as shown in FIG. 8
The thick sheet 4b is loaded on the loading section 8a of the sheet 4b.
The guide portions 8b are brought into contact with both ends of the guide F.

When the shaft 10 is rotated in the above state, a propulsive force is applied to the recording sheet 1-4b by the arc portion 5b of the feeding roller 5, as in the case of feeding the normal sheet 1-4a.

At this time, since the dimensions of the separation claw 6 are set as described above, the one sheet of the seal l-4b on the top layer lightly hits the upper end of the abutment part 6b and escapes above the abutment part 6b. Then, only one sheet of the top layer is separated and sent to the nip between the conveyance roller 7 and the pinch roller 7a (.

Here, the thick sheets 4b are sequentially fed as described above,
To explain the discomfort when there are only two remaining sheets, as shown in FIG. There is.

Furthermore, since the high-friction sheet 1-9 is provided on the placing portion 8a located below the separation claw 6, the front corner of the bottom layer sheet 4b is pressed against the high-friction sheet 9. ing.

Therefore, when the sheet 1-4b is conveyed by the conveying roller 7 and the pinch roller 7a, the feeding roller 5
Even if they are separated from each other, the frictional force between the bottom sheet 4b and the high friction sheet 9 is greater than the frictional force between the sheets, and the second sheet 4b from the bottom is completely separated from the bottom sheet 4b. There is no possibility of so-called last double feeding.

Incidentally, when feeding the normal sheet 4a, the side guide member 8 is removed, so that the frictional force produced by the high friction sheet 9 does not affect the side guide member 8.

(Other Embodiments) In the above-mentioned embodiments, an example was shown in which an arcuate roller was used as the feeding roller 5, but when a normal circular roller is used and the sheet 4b is conveyed by the conveying roller 7, If the feed roller is configured to be in contact with the sheet 1-4b, the friction saw by the sheet 9 can be more effectively applied to the bottom layer sheet 1-4b, and reliable double feeding can be achieved. This can be prevented.

Furthermore, in the above-mentioned embodiment, the high friction sheet 9 is provided on substantially the entire surface of the placing portion 8a, but if the coefficient of friction between the high friction sheet 9 and the sheet 4b is high, the sheet 9 may be placed between the separation claws 6. It may also be provided only at the bottom.

Furthermore, in the above-mentioned embodiment, an example was shown in which the separation claw 6 was formed integrally with the frame 1, but the claw portion 6aCDh was formed integrally with the frame 1, and the abutment portion made of a separate member from the claw portion 6a was formed. 6b may be attached to the frame 1 with screws or the like. In this way, it is possible to easily improve the precision of the dimensions and shape of the sulin (6c), which is difficult to obtain with precision by integral molding by bending, by determining the dimensions with the positional precision of two parts.

<Effects of the Invention> As described above, the present invention has a removable structure in which the side guide members for guiding both ends of a thick sheet can be attached and removed. can be separated and fed.

Furthermore, since a high friction sheet is provided in the portion located below the separating claw when the above-mentioned member is attached, it is possible to prevent so-called last double feeding when feeding thick sheets.

[Brief Description of the Drawings] The first part is a perspective view of a sheet feeding device according to an embodiment of the present invention, and the second part is an explanatory view of feeding a normal sheet.
Fig. 3 is an explanatory diagram when feeding a thick sheet, Fig. 4 is an explanatory diagram of the configuration of the separating claw, Fig. 5 is an explanatory diagram when feeding a thick sheet, and Fig. 6 is an explanatory diagram of the conventional technology. It is. ■ is a frame body, 1a is a left half, 1b is a right half, 2 is a pressure spring, 3 is a mounting plate, 4a and 4b are sheets, 5 is a feeding roller,
5a is a protrusion, 5b is an arc, 5c is an arc, 6 is a separation claw,
6a is a claw portion, 6b is an abutment portion, 6C is a slit, 7 is a conveyor roller, 7a is a pinch roller, 8 is a side guide member,
8a is a mounting part, 8b is a side guide part, 9 is a high friction sheet, 10 is a shaft, 10a is a groove part, and 11 is a side guide.

Claims (1)

[Scope of Claims] A mounting member for mounting a sheet, a claw portion for pressing the top surface of the uppermost sheet of the sheets stacked on the mounting member, and an abutting portion against which the front end of the sheet abuts. , a separating claw having a slit formed between the claw part and the abutting part; a feeding means for applying feeding force to the sheet in the uppermost layer; and a thick sheet side guide member having a high friction sheet at a predetermined position, and when the thick sheet side guide member is attached to the mounting member, the high friction sheet is attached to the claw of the separating claw. A sheet feeding device characterized in that it is configured to fit under the section.