JPS62191337A - Sheet feeder - Google Patents

Abstract

PURPOSE:To prevent a sheet tip from being turned up and hitched on a device, by controlling both drive and positions of a semicircular rotor with a clutch mechanism. CONSTITUTION:When a semicircular roller 21 and a separation pad 25 are in a state of being separated, if a sheet is doubly fed as much as more than two sheets, an idler 23 and the pad 25 are frictionally contacted with each other so that the sheet at a lowermost position is separated from the sheet at an uppermost position, thus only the sheet in the uppermost position is conveyed. When the sheet is stacked on a loading block 27', since the semicircular roller 21 is stopped at a position where a straight line connecting a point (b) and a point (a) to a straight line in a sheet inserting direction (c) makes an elevation angle with the sheet inserting direction (c), the semicircular roller 21 keeps the stop position. And, if loading of the sheet is carried out in the state that the sheet loading block 27' is pressed down by a cam 30, space to be formed by the semicircular roller 21 and the sheet loading block 27' becomes widened, so that such a fear that a sheet tip is turned up and hitched on a device part will never happen.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention relates to a sheet feeding device for copying machines, facsimile machines, laser beam printers, etc. The present invention relates to a sheet feeding device that increases the sheet loading capacity by increasing the space.

(B) Conventional technology Conventionally, as shown in FIG. 5, a sheet feeding device has a circular roller 1 and a separation pad 2, and the circular roller 1 is pivotally supported on the main body of the device (not shown). The separation pad 2 is fixed to the shaft 3 which is fixed to the seat 1, and is provided at the flat front end of the lower guide plate 5 of the upper and lower guide plates 5, 5 forming the conveyance path, and is kept in constant use by a spring 6. It is pressed against the roller 1 at a predetermined pressure and is in frictional contact with the circular roller 1. Further, a sheet loading table 7 on which sheets 1-P are placed is arranged upstream of the circular roller 1, and the sheet loading table 7 is urged with its free end toward the roller 1 by a spring 7'. ing. On the other hand, the sheet loading platform 7 is normally pushed down by the cam 9, and when the sheets 1-P are fed by the circular roller 1, the cam 9 rotates as shown by the arrow and pushes the sheet loading platform downward. 7 rises, the uppermost sheet of the sheets P comes into contact with the circular roller 1, and the sheet is fed. When two or more sheets are fed, the feeding of the lower sheet is regulated by pressure contact with the separation pad 2, thereby preventing double feeding in which two or more sheets are fed. Further, there is a space between the sheet loading table 7 and the circular roller 1 for loading the sheets P.
Depending on the size of the space, sheets that can be loaded on the sheet loading platform 7! When the number of sheets P is determined and the cam 9 is rotated and positioned downward, the maximum number of sheets P can be loaded, and when more sheets than the specified amount are pushed in, the sheets P are moved to the circular roller 1 as shown in the figure.
It gets crumpled due to interference. In addition, 10 is a one-way clutch that controls the rotation of the circular roller 1, 11 is an upper
This is a pair of conveyance rollers disposed downstream of the lower guide plates 5, 5.

On the other hand, in the above-mentioned sheet 1-feeding device, the number of sheets on the sheet loading platform 7 is regulated by the cam 9, so as shown in FIG. It is also conceivable to increase the loading capacity of the sheet loading platform 1.

t/→ The problem that the invention seeks to solveHowever,
In the conventional device described above, the width of the vertical movement of the sheet loading table 1 due to the rotation of the cam 9 is limited due to its structure, and if an attempt is made to load more than that, the leading edge of the sheet will come into contact with the circular roller 1, resulting in a jam. Put it away. On the other hand, in the proposed example that is an improvement on the conventional device described above, the space between the circular roller 1 and the sheet loading table 7 is too large, which affects the arrangement of other devices within the device body, and increases the cost in terms of space. This poses a problem in that it actually becomes a disadvantage.

(b) Means for Solving the Problems The present invention aims to solve the above-mentioned problems, and uses a rotating body to feed sheets on a vertically movable sheet loading platform! i In a sheet feeding device that separates and feeds each rubbing member one by one, the feeding rotating body is a semicircular rotating body with a part of its circumference cut out, and the driving and stopping positions of the semicircular rotating body are controlled by a clutch. The semi-moon-shaped rotating body is controlled by a mechanism, and the semi-moon-shaped rotating body is controlled by a point on the semi-moon-shaped rotating body that is closest to the straight line in the sheet insertion direction and a point on the semi-moon-shaped rotating body that comes into contact with the sheet for the first time when the semi-moon-shaped rotating body rotates. This feature is characterized in that the straight line connecting the points stops at a position that forms an elevation angle with the sheet insertion direction.

(E) Function Based on the above configuration, the half-moon-shaped rotary body that rotates clockwise to feed sheets one by one has its stopping position controlled by a clutch mechanism, and is located at the position closest to the straight line in the sheet insertion direction. The straight line connecting the point on the semi-moon-shaped rotating body and the point on the semi-moon-shaped rotating body that first comes into contact with the sheet when the semi-moon-shaped rotating body rotates is stopped at a position that forms an elevation angle with the sheet insertion direction, so that the sheet is not inserted into the sheet. When loading onto the loading platform, keep the half-moon-shaped rotary body at its stop position and push the sheet loading platform downward; the space formed by the half-moon-shaped rotary body and the sheet loading platform can be widened ( This prevents the leading edge of the sheet from curling up or getting caught in the device, allowing the sheet to be loaded smoothly and increasing the sheet loading capacity.

(F) Embodiment Hereinafter, an embodiment in which the present invention is applied to a sheet feeding device of a laser beam printer will be described with reference to the drawings.

The sheet feeding device, as shown in FIGS. 1 to 3,
It has a half-moon roller 21 with a substantially flat portion formed by cutting off a part of its circumference, and the half-moon roller 21 is fixed to a shaft 22 and rotates clockwise to feed the sheet P. , a pair of idlers 23, 23 are installed on both sides of the half-moon roller 21.
are shafts 23', 23' supported by the main body of the device (not shown).
is supported by The separation pad 25 is provided at the flat end of the lower guide plate 26 of the lower guide plates 26 and 26 forming the sheet conveyance path, and is applied with a predetermined pressure by a spring 27 to prevent the half-moon roller 21 and the pair of idlers 23 from forming the sheet conveyance path. It is in frictional contact with .23. Also, half-moon roller 21
Upstream of , there is a sheet loading table 27' on which sheets P are placed.
The sheet loading platform 27' is urged by a spring 29 so that the free end of the slant is directed toward the crescent 4-ra 21. On the other hand, the sheet loading platform 27' is normally pushed downward by the cam 30, and when the half-moon roller 21 is rotated by a clutch mechanism to be described later to feed the sheet P, the cam 30 is also pushed down by a control mechanism (not shown). Due to the rotation, the sheet loading platform 27' is pulled upward by the spring force of the spring 29 and pushed up, so that the uppermost sheet comes into contact with a part of the half-moon roller 21 to ensure that the sheet is fed. It has become. Further, the shaft 22 of the half-moon roller 21 is provided with a clutch mechanism that controls the driving and stopping position of the half-moon roller 21, and the clutch mechanism is connected to the second half-moon roller 21.
As shown in the figure and FIG. 4(a), it consists of a spring clutch 31 and a solenoid 32 arranged on a shaft 22, and the half-moon roller 21 is stopped at a fixed position every rotation, and this operation is repeated. There is.

Further, the outer casing of the spring clutch 31 is provided with a protrusion 33, and the end of the sliding rod 32' of the solenoid 32 has a lower extending portion 35 with one end extending downward. A letter-shaped plate-like body 36 is fixedly provided, and a tension spring 37 is locked to the other end of the letter-shaped plate-like body 36. When the solenoid 32 is off, the sliding rod 32' moves downward due to the spring force of the tension spring 37, and the L-shaped body 36 is also pushed downward, so that the lower extension 35 is connected to the spring clutch 3. ]
The spring clutch 31 is engaged with a protrusion 33 of the spring clutch 31 to stop the spring clutch 31 at a fixed position. Therefore, half-moon roller 2
1 is also stopped at a fixed position, and as shown in FIG. The straight line connecting the point a on the half-moon roller 21 that first comes into contact with the sheath P is stopped at a position forming an elevation angle with the sheath I and the insertion direction C. Incidentally, reference numeral 39 denotes a pair of conveying rollers disposed downstream of the upper and lower guide plates 25 and 26 for conveying the sheet.

Since this embodiment has the above-described configuration, when the start key (not shown) is pressed, an output signal is transmitted to the solenoid 32, which turns on, and the sliding rod 32'
moves upward against the spring force of the tension spring 37, so the L-shaped plate-like body 35 also moves upward.

Then, the engagement between the lower extending portion 36 of the L-shaped plate-like body 35 and the protrusion 33 of the spring clutch 31 is released, so that the shaft 2
The half-moon roller 21 fixed to 2 rotates clockwise.

On the other hand, since the cam 30 is also rotated clockwise by a control mechanism (not shown), the sheet loading table 27' is moved upward by the spring force of the spring 29. Therefore, sheet loading platform 2
The uppermost sheet P on 7' comes into contact with point a of the half-moon roller 21 rotating clockwise, so the uppermost sheet P is fed downstream due to the contact friction with the half-moon roller 21, and is fed downstream by the idler. 23 and the separation pad 25, and passes through the conveyance path consisting of the upper and lower guide plates 25 and 26 to the conveyance roller pair 3.
9 and the top sea 1. P is further transported to the next step by the transport roller pair 39. On the other hand, when the half-moon roller 21 rotates further and the point a of the half-moon roller 21 approaches upward, the solenoid 32 is turned off by a control mechanism (not shown), and the sliding rod 32' is moved downward by the spring force of the tension spring 37. , the lower extending portion 36 of the L-shaped plate-like body 35 also descends and engages with the protrusion 33 of the spring clutch 31. Therefore, the half-moon roller 21 rotates once and stops at a fixed position, and the same operation is repeated thereafter.

Furthermore, when the half-moon roller 21 and the separation pad 25 are separated, the idler 23 and the separation pad 25 are in frictional contact even if two or more sheets are fed, so the lowest sheet is in contact with the highest sheet. The sheets are separated and only the topmost sheet is transported. See you again! When stacking the half-moon roller 21 on the sheet loading table 27', the half-redundant roller 21 contacts the sheet first when the half-moon roller 21 rotates at the point on the half-moon roller closest to the straight line in the sheet insertion direction C. half moon roller 2
1 is stopped at a position where the straight line connecting point a on top 1 forms an elevation angle with the sheet insertion direction C, the half-moon roller 21 is kept at that stop position, and the sheet loading table 27' is pushed downward by the cam 30. When the sheet is lowered, the space formed by the half-moon roller 21 and the sheet loading table 27' becomes wider, so the leading edge of the sheet does not curl up or get caught in the device parts, and the sheet can be loaded smoothly. Moreover, the sheet loading capacity also increases.

In this embodiment, since the half-moon roller 21 is used as the sheet feeding roller, the idler 23 is provided as a means for preventing double feeding of sheets when the half-moon roller 21 and separation pad 25 are separated from each other. The idler 23 may be provided on the same shaft 22 as the half-moon roller 21. Furthermore, a smooth member with low frictional resistance may be used instead of the idler 23. Furthermore, although the sheet stacking table 27' is shaped like a tray, it may also be a cassette.

Furthermore, if the substantially flat portion of the half-moon roller 21 that forms an elevation angle with the sheet insertion direction is smooth and made of a low-friction material, even if the sheet contacts the half-moon roller 21 when inserting the sheet, the sheet can be inserted smoothly. can.

FIG. 4(b) shows another embodiment of the clutch mechanism, in which a plurality of uneven parts 40 are formed on the outer casing of the spring clutch 31, and the half-moon roller 21 is rotated halfway through one rotation. If you want to stop the spring clutch 3, turn off the solenoid and idler 32 and engage the lower extension 36 of the L-shaped plate member 35 with any of the plurality of concave and convex portions 40.
In order to stop the half-moon roller 21, the half-moon roller 21 can be stopped at any arbitrary position during one rotation. Furthermore, if the position of the half-moon roller 21 is detected by a sensor or the like, it is possible to stop the half-moon roller at an arbitrary position using an electromagnetic clutch.

The present invention can be applied not only to sheet feeding devices such as copying machines, facsimile machines, and laser beam printers, but also to sheet document automatic feeding devices.

(G) As described in detail, the present invention provides a sheet feeding device that separates and feeds sheets on a vertically movable sheet stacking table one by one using a feeding rotary body and a friction member. , the feeding rotary body is a half-moon-shaped rotary body with a part of its circumference cut off, the driving and stopping positions of the semi-moon-shaped rotary body are controlled by a clutch aIH1t, and the semi-moon-shaped rotary body is arranged in the sheet insertion direction. A straight line connecting the point on the semi-moon-shaped rotating body closest to the straight line and the point on the semi-moon-shaped rotating body that first contacts the sheet when the semi-lunar rotating body rotates forms an elevation angle with the sheet insertion direction. Since it stops at the position, the space formed by the half-moon-shaped rotating body and the sheet loading table becomes larger, and when inserting sheets, the sheet can be loaded on the sheet loading table without the leading edge of the sheet curling up and jamming. Moreover, the sheet loading capacity can also be increased.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the sheet feeding device, FIG. 2 is a partially cutaway perspective view of FIG. 1, and FIG. 3 is a longitudinal sectional view showing the sheet inserted state in FIG. FIG. 4(a) is a longitudinal sectional view showing one embodiment of the clutch mechanism, FIG. 4(b) is a longitudinal sectional view showing another embodiment of the clutch mechanism, and FIG. 5 is a longitudinal sectional view showing a conventional sheet feeding device. FIG. 6 is a vertical cross-sectional view showing another conventional sheet feeding device. 21... Half-moon-shaped rotating body (roller), 23... Idler, 25... Separation pad,
27'... Sheet loading platform, 30... Cam,
31...Spring clutch, 32...Solenoid, 33...Protrusion, 35...L-shaped plate body,
36...Lower extension part.

Claims (2)

[Claims] (1) In a sheet feeding device in which sheets on a vertically movable sheet stacking table are separated and fed one by one by a feeding rotary body, the feeding rotary body is a half-moon-shaped rotary body with a part of its circumference cut off. The driving and stopping positions of the semi-lunar-shaped rotating body are controlled by a clutch mechanism, and the semi-lunar-shaped rotating body is connected to a point on the semi-lunar-shaped rotating body closest to a straight line in the sheet insertion direction. A sheet feeding device characterized in that when the rotating body rotates, the rotating body stops at a position where a straight line connecting a point on the half-moon-shaped rotating body that first comes into contact with the sheet forms an elevation angle with the sheet insertion direction. (2) A sheet feeding device according to claim 1, characterized in that, in the semi-moon-shaped rotating body, a substantially flat portion forming an elevation angle with the sheet insertion direction is smooth and made of a low-friction material. .