JPH02178114A - Sheet feeder - Google Patents

Abstract

PURPOSE:To keep off any feeding failure due to a turnup or a curl at a sheet tip by tilting a sheet contact surface of a loading sheet tip position regulating member on a sheet loading means to the side of this loading means to some extent. CONSTITUTION:In a sheet tip regulating member 21 regulating a tip of a sheet S loaded on a paper feed tray 6, there is formed with a rib 21b whose ridgeline is tilted as far as about 3 degrees to the side of the tray 6 from a vertical line. Then, a separate pad 22 consisting of a high directional member of rubber or the like is fixed to a mount 23 at a lower part of the tip regulating member 21. With this constitution, since the tip regulating member 21 is tilted to the side of the sheet S, the sheet tip is pressed to the tip regulating member 21 in accordance with a drop of the sheet S with the sheet feeding, thus any turnup or curl of the tip is checked. Consequently, a possible feeding failure is thus preventable.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a sheet stacking means (hereinafter referred to as a paper feed tray) for stacking sheets used in image forming apparatuses such as copying machines and laser beam printers, and a feed rotation system. The present invention relates to a sheet feeding device that includes a body (hereinafter referred to as a sheet feeding roller) and a pressing member (hereinafter referred to as a weight) that presses and biases a sheet toward the sheet feeding roller.

[Conventional technology]

Hitherto, a rate feeding device comprising a paper feed tray, a paper feed roller, and a weight has been known, and the present applicant has also disclosed a patent application filed in 1983.
It is proposed in No.-275392. In this case, the sheet contact surface of the regulating member that regulates the leading edge of the stacked sheets is perpendicular to the paper feed tray, and the sheet contact surface of the regulating member that regulates the leading edge of the stacked sheets is perpendicular to the paper feed tray, and the sheet is fed from the vertical plane by the same angle as the inclination of the paper feed tray with respect to the horizontal plane. It was tilted in the same direction as the paper tray.

[Problem to be solved by the invention] Because of this configuration, in the conventional example described above, as the stacked sheets are fed sequentially from the bottom, the sheets stacked at the top are vertically moved by the biasing force of the weight. (However, at this time, the leading edge of the sheet is forcibly pressed against the leading edge regulating member, and the leading edge of the sheet tends to curl up. In many cases, excessive frictional force is generated during the separation process using a separation pad, etc., making feeding impossible. 11, the sheet 5 on the paper feed tray 6 is fed from below by the rotation of the paper feed roller 16 under pressure in the direction of arrow 100 by the weight 17, but the sheet 5 on the paper feed tray 6 is fed from below by rotation of the paper feed roller 16. 21 is tilted in the direction shown in the figure by θ1, the leading edge of the sheet falling vertically turns upward and curls as shown in 101, and when the sheet with the curled leading edge is fed, the high frictional force of the separation pad 22 is applied. The surface of the curled sheet comes into contact with the surface of the sheet, preventing the sheet from advancing, making it impossible to feed the sheet.Furthermore, the sheet with the curled tip tends to jam during conveyance, which also causes problems in image formation.

[Means for Solving the Problems (and Effects)] The present invention has been made to solve the above problems, and its purpose is to prevent feeding defects due to curling or curling of the leading edge of the sheet. In order to achieve the above object, the present invention has a structure including a sheet stacking means for stacking a plurality of sheets, a feeding rotary member for feeding the sheets stacked on the sheet stacking means from below, and the above-mentioned In a sheet feeding device comprising a suppressing means that comes into contact with the uppermost sheet stacked on the sheet stacking means and presses the sheet against the feeding rotating body, a leading edge that regulates the leading edge position of the stacked sheets. A sheet feeding device characterized in that the sheet contacting surface of the regulating member is vertical or inclined toward the sheet loading means with respect to the vertical.

Claims characterized in that the sheet contact surface is constituted by a rib-shaped member, and the sheet contact surface at the tip of the rib is inclined toward the sheet loading means in a range of 0-10' from the vertical. This is the sheet feeding device of item 1.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the sheet feeding device l is installed on the side of the laser beam printer 2 and above the cassette 3 that is detachably attached to the side of the printer 2. Positioning guide rods 5a and 5b provided at the base end are inserted into holes (not shown) drilled in the printer 2.
The guide rods 5a and 5b have grooves at their tips for locking the feeding device l to the printer 2. At the top of the cassette 3, a manual feed port 2a into which a manual feed port is inserted is provided. Further, the sheet feeding device 1 has a paper feeding tray 6 for stacking sheets, and the tray 6 is provided with regulating plates 7a and 7b for regulating movement of the sheets in the width direction. Further, a rack 9 is disposed at the bottom of the width regulating plate 7a, and a rack 10 is disposed at the bottom of the width regulating plate 7b, and these racks 9 and 10 mesh with the pinion gear 11. This allows it to move in the sheet width direction. The paper feed tray 6 is provided with a sheet presence/absence sensor 12 that detects the presence or absence of sheets. O
It is composed of a photointerrupter 15 which is turned off. Further, on the downstream side of the sensor 12, a paper feed tray 6 is provided.
A paper feed roller 16 that feeds the sheets stacked on the paper from below.
are rotatably supported, and above the roller 16 there are arcuate holes 19a, 20a bored in the side plates 19, 20, and weights 17 for pressing the sheet against the roller 16.
Pivot shafts 30a, 30b so as to be able to move up and down along the
It is rotatably supported on the top (see Figure 3). Furthermore,
A leading edge regulating member 21 is disposed near the weight 17 to regulate the leading edge of sheets stacked on the paper feed tray 6. The lower end of the member 21 and the downstream end of the paper feeding tray 6 are arranged at a predetermined distance. They are separated by a certain distance, and sheets can be fed from this separated portion 21a. Further, the leading edge regulating member 21 has a rib 21b to reduce friction with the sheet and prevent the leading edge of the sheet from becoming bent, and its ridge line is inclined by about 3 degrees toward the paper feed tray 6 side from the vertical line. There is.

A separation pad 22 made of a high-friction member such as rubber is fixed on a mounting base 23 at the bottom of the tip regulating member 21.
6 by a predetermined distance and is inclined at a predetermined angle with respect to the sheet feeding direction. Further, a flexible sheet-like member 24 is provided at a position facing the separation pad 22, and presses the sheets fed by the paper feed roller 16 in the direction of the separation pad 22 to prevent double feeding. . Further, a guide 25 for guiding the sheet is disposed downstream of the separation pad 22, and a conveyance roller pair 26 consisting of a drive roller 26a and a pinch roller 26b is disposed downstream of the guide 25. It is set up. The separation pad 22 and the sheet-like member 24 are fixed on the same mounting base 23, and the mounting base 23 can be easily removed downward.

Furthermore, a connector 27 is provided on the downstream side of the roller pair 26, and a connector (
(not shown), and performs all electrical connections between the printer 2 and the sheet feeding device l.

Detection of whether the sheet feeding device 1 is attached to the printer 2 can be made on the printer 2 side by shorting two contacts on the connector 27.

FIG. 2 shows a state in which sheets S are loaded on the sheet feeding device l. As the paper roller 16 rotates, the sheets are sequentially fed starting from the lowest position. Also,
When the sheet S is present on the paper feed tray 6, the sensor lever 13 is rotated counterclockwise. Further, a photointerrupter 15 on a control board shown in FIG. 5, which will be described later, and one end 13a of the sensor lever 13 engage with each other to detect rotation of the lever 13.

3 and 4 show the state in which the weight is released by opening and closing the lid. In the figures, the lid 4 is rotatable around a hinge 52 fitted into holes provided in the side plates 19 and 20. There are hooks 8a and 8b on both sides. On the other hand, both ends of the weight 17 have holes 14c in the arms 14a and 14b.
, 14d with a certain degree of play (degree of freedom), and each engaging portion is prevented from coming out.

The arms 14a and 14b are rotatably locked at their other ends to hinge shafts 30a and 30b fixed to the side plates 19 and 20. There are spring hooks 53a, 53b near the center of the arms 14a, 14b, respectively, and guide hooks 5a, 5.
A tension spring 29a between the fixing fittings 28a and 28b of b.
29b is stretched. Also, arm 14a
, 14b are fixed with dowels 18a, 18b near the center thereof, and are positioned to engage with the tips of the hooks 8a, 8b of the lid 4.

Next, the drive system will be explained with reference to FIGS. 5, 6, and 7.

In the figure, 3I is the drive side plate that serves as the base of the drive system, and 32
is fixed on a drive side plate 31 by a drive motor (in this embodiment, a pulse motor), and the drive side plate 31 also serves as a heat sink for the motor 32. In addition, the drive side plate 31 has a guide rod 5.
The fixing bracket 28b of b is fixed, and the guide rod 5b
By bringing the tip of the feeder l into contact with the frame of the printer 2, the feeding device l is grounded.

[Transmission system from motor 32 to paper feed a-ra 16] The output of the motor 32 is transmitted through the gear 33 on the output shaft. Gear 34° 2nd gear 3
5. Gear 36. Gear 3 with one-way clutch 56
8, and drives the paper feed roller 16 which is rotatably supported by a sliding bearing 51 on the side plate 20 side and a metal bearing 49 on the side plate 19 side. The one-way clutch 56 locks and feeds the sheet when the motor 32 rotates in the direction of an arrow 57 (indicated by a solid line in FIG. 6), and when the motor 32 rotates in the direction of an arrow 58 (indicated by a broken line), it idles and feeds the sheet. 16 is inserted in a direction that does not rotate.

[Transmission system from motor 32 to conveying roller pair 26] The transmission system from the motor 32 to the gear 36 is the same as the transmission system from the paper feed roller 16, and will therefore be omitted. The transmission system from the gear 36 to the transport roller pair 26 is divided into two transmission systems.

The first system is gear 36. Gear 37. Gear 39. This is a transmission system in which driving force is transmitted in the order of gear 40 and gear 41 with one-way clutch 55 engaged. Here, the one-way clutch 55 is locked when the motor 32 rotates in the direction of the broken line 58, causing the drive roller 28a to rotate counterclockwise in FIG. The second system performs transmission from the side plate 20 side using a gear 39 and a through shaft 47 that is prevented from rotating by a pin. The through shaft 47 is rotatably supported by a metal bearing 50 fitted to the drive side plate 31 and a bearing 52 fitted to the side plate 20, and a gear 42 is prevented from rotating at the other end by a pin. Drive is transmitted from gear 42 to gear 45, which includes one-way clutch 54, via gears 43 and 43. Here, the one-way clutch 54 locks when the motor 32 rotates in the direction of the solid arrow 57 and locks the drive roller 26a.
Rotate counterclockwise in Figure 1.

Due to the first and second transmission systems, the rotation direction of the drive roller 26 is always counterclockwise in FIG. 1, regardless of the rotation direction of the motor 32. torsion coil spring 48a,
48b is coaxial with the through shaft 47 and inserted into posts 19b and 20b which are part of the side plates 19 and 20, and one end thereof urges the shaft end 26C926d of the pinch roller 26b in the direction of the drive roller 26a, The other end is positioned using a dowel 19c provided on the side plate 19 or a support shaft 44a of a gear 44 provided on the side plate 20 as a stopper.

The locking portion of the lid 4 will be explained according to FIGS. 8, 9, and 1O. In the figure, reference numeral 59 denotes a leaf spring that urges a pin 60, which is retractably fitted into a hole in the side plate 19 (20), toward the inside of the side plate, and the tip of the pin 60 projects inside the side plate. Reference numeral 61 denotes a member connecting the lid 4 and the hinge 52 of the lid 4, and a hole 62 is bored at the tip thereof. In addition, the hole 62 is open when the lid 4 is open (opening angle 25
30°) at a position where it engages with the tip of the pin 60.

In the above configuration, when stacking sheets S on the paper feed tray 6, first lift the lid 4 and widen the opening (then,
Hooks 8a and 8b are dowels 1 of arms 14a and 14b
8a and 18b and pull them up, the weight 17 is lifted upward in conjunction with the opening operation of the lid 4,
The lid 4 is stopped at the open position by the locking mechanism of the lid 4, and the weight 17 is also stopped at the same time. Next, slide the sheet S onto the paper feed tray 6 and insert it until the leading edge hits the leading edge regulating member 21. When the lid 4 is closed, the weight 17 rides on the topmost sheet of the sheet S, and the weight 17 itself weight and spring 53a.

A pressing force acts in the direction of the paper feed roller 16 due to the biasing force of 53b. When the sheet S is inserted, the sensor lever 13
is pressed, and the presence of the sheet is detected. In response to a paper feed signal from the printer, a motor start signal is issued from the control board 46, and the motor 32 starts rotating in the direction of the arrow (solid line) 57 in FIG. 6, and the bottom sheet is fed out by the paper feed roller 16. The tip of the sheet is separated by the separation pad 22.
The sheets are separated one by one by coming into contact with them, and are sent to the next pair of conveying rollers 26. The motor 32 rotates in the direction of the arrow (broken line) 58 in FIG. 6, that is, in the reverse direction, before the trailing end of the sheet is fed into the pair of transport rollers 26 and removed from the feed roller 16. Then, only the conveying roller pair 26 is rotationally driven to further feed out the sheet. The paper feed roller 16 rotates as a result of the movement of the sheet.

Then, the motor 32 continues to rotate until the leading edge of the sheet is sufficiently pushed into the next conveyance roller (such as a paper feed roller of a printer) and passes through the conveyance roller pair 26, and then stops. Continuous paper feeding is performed by repeating the above operations. When the sheets S are fed in order from the bottom, the remaining sheets S gradually descend due to the biasing force of the weight and spring 29a, and at this time, the leading edge of the sheet rubs against the leading edge regulating member 21. However, since the ridgeline of the leading edge regulating member 21 is tilted toward the sheet S side than the vertical line, the leading edge of the sheet as the seat descends is aligned with the leading edge regulating member 21.
There is no possibility that the leading edge of the sheet will smear due to being pressed by the paper, and therefore paper feeding failures due to the leading edge of the sheet will not occur. When the paper feed progresses further and reaches the final two sheets, the top sheet has a weight of 17.
A friction member 63 provided on the sheet contact surface side prevents paper feeding, and only the lower sheet is fed. (When the last two sheets have been fed, the sheet presence/absence sensor 12 generates a no-sheet signal. Then, it notifies the printer itself and ends the paper feeding operation.

Also, as the sheet decreases, the tension spring 29a.

29b becomes shorter and the tension is reduced. Therefore way) 1
As the pressing force sheet due to 7 decreases, it decreases (
.

FIG. 12 shows the inclination of the tip regulating member.

The sheet contacting surface of the tip regulating member 21 is inclined by 02 toward the sheet with respect to the vertical line. That is, the sheet is fed and the sheet stacked at the top is vertically lowered together with the weight 17, but due to the above-mentioned inclination, the leading edge regulating member 21 is moved away from the sheet being lowered. Therefore, the sheet will not roll up or curl.

In FIG. 13, the weight 17 rotates around a fulcrum 30. In this case as well, the sheet abutting surface of the rib 21b of the tip regulating member 21 is inclined toward the sheet by θ2. Even when the weight 17 moves down in an arc, the sheet does not turn up or curl.

Note that the inclination of the sheet contact surface is preferably 10° C. or less, but may be vertical.

〔Effect of the invention〕

As explained above, by tilting the sheet abutting surface of the sheet leading edge regulating member toward the sheet loading means from the vertical plane or the vertical plane, it is possible to eliminate curling or curling of the sheet leading edge, encourage smooth sheet descent, and feed the sheet. This makes it possible to prevent poor feeding.

[Brief explanation of the drawing]

FIG. 1 is a main sectional view of a first embodiment of the present invention. FIG. 2 is a sectional view showing a state in which sheets are stacked in the first embodiment of the present invention. FIG. 3 is a side view of the first embodiment of the invention. FIG. 4 is a side view of the first embodiment of the present invention (with the lid open). FIG. 5 is a top view of the first embodiment of the present invention. FIG. 6 is a side view of the drive side of the first embodiment of the present invention. FIG. 7 is an exploded view of the drive system of the first embodiment of the present invention. FIG. 8, FIG. 9, and FIG. 10 are detailed views of the locking portion of the lid according to the first embodiment of the present invention. FIG. 11 is a schematic diagram of a conventional example. FIG. 12 is a schematic diagram of the present invention. FIG. 13 is a schematic diagram of the experimental apparatus of the present invention. 1 is a sheet feeding device, 4 is a lid, 5 is a guide bar, 6 is a paper feed tray, 7a, 7b are side pressers, 8a, 8b
12 is a hook, 12 is a sheet presence/absence sensor, 14 is a weight arm, 16 is a paper feed roller, 21 is a sheet leading edge regulating member, 26 is a pair of transport rollers, and 29 is a spring. Male criminal Kuzu 12 drawings θtsu

Claims (2)

[Claims] (1) A sheet stacking means for stacking a plurality of sheets, a feeding rotary member for feeding the sheets stacked on the sheet stacking means from below, and a feeding rotary member for feeding the uppermost sheet stacked on the sheet stacking means. In the sheet feeding device, the sheet feeding device is provided with a pressing means for pressing the sheet against the feeding rotary body, the sheet contacting surface of the leading end regulating member regulating the leading end position of the stacked sheets being vertical or less than vertical. A sheet feeding device characterized by being inclined toward a sheet loading means side. (2) A patent claim characterized in that the sheet contact surface is constituted by a rib-shaped member, and the sheet contact surface at the tip of the rib is inclined toward the sheet loading means in a range of 0 to 10 degrees from the vertical. Sheet feeding device of range 1.