JPH0647418B2 - Sheet feeding device - Google Patents

Description

The present invention relates to a sheet feeding device such as a copying machine, a facsimile, a laser beam printer, etc., and more specifically, the sheet feeding means has a missing roller or a cam shape. The present invention relates to a sheet feeding device including a member and auxiliary means.

(B) Conventional Technology Conventionally, as shown in FIG.
It has a feeding roller 1 and a separation pad 2, and the roller 1 is fixed to a shaft 3 which is axially supported by a machine body (not shown), and the separation pad 2 forms a sheet conveyance path. The upper and lower guide plates 5 and 6 are provided at the front end of the lower guide plate 6, and are configured to be constantly in pressure contact with the paper feed roller 1 by a spring 7 at a predetermined pressure so as to make frictional contact with the paper feed roller 1. There is. Further, the sheet S has an intermediate plate 9 at the upstream side of the roller 1.
A cassette 10 to be loaded on top is provided, and the middle plate 9
Is urged toward the paper feed roller 1 by the intermediate plate lifting device 11. In the figure, 12 is a one-way clutch that controls the rotation of the feeding roller 1, and 13 is a pair of registration rollers disposed downstream of the upper and lower guide plates 5 and 6.

When a start key (not shown) is pressed, the feeding roller 1 rotates (clockwise in the illustrated example) to feed the uppermost sheet S. At this time, when the second sheet S is fed together with the uppermost sheet S by electrostatic attraction or the like, the feeding of the second sheet S is restricted by the pressure contact of the separation pad 2, This prevents double feeding of one or more S sheets.

(C) Problems to be Solved by the Invention However, in the sheet feeding device described above, the feeding roller 1 is
At the start of feeding, the separation pad 2 is directly in contact with the pad so that it is easily worn. Further, since the feeding roller 1 has a circular shape, manual feeding is difficult. When the feeding roller 1 feeds a plurality of sheets from the cassette 10, the separation pad 2
However, due to the large frictional force between the sheets due to the frictional force between the sheets, only the uppermost sheet is fed to prevent double feeding.
If the two sheets overlap, the two sheets are fed together. (Double feed) will occur.

(D) Means for Solving the Problem The present invention is intended to solve the above-mentioned problems, and the sheet feeding means is connected to the rotation transmitting shaft (3), A cutout roller (1a) which has a cutout portion (b) obtained by cutting out a part of (1a), and whose peripheral portion comes into contact with the sheet (S) stored in the sheet storage device (10) and sends it out. And an auxiliary member that separates the cutting portion (b) from the separation pad (2) when the cutting portion (b) of the missing circle roller is not fed to the sheet positioned corresponding to the sheet storage device. (16)
And, connected to the shaft (3), from the cutting portion (b) to the circumferential portion (a) in the rotation direction of the lacking roller (1a).
A cam-shaped member (15) having a portion (c) projecting outward from the truncated circle roller (1a) near a position corresponding to the portion (F-A) that moves to When the circumferential portion (a) of (1a) contacts the sheet (S) and starts feeding, the protruding portion (c) of the cam-shaped member (15) is the separation pad (2).
The sheet feeding device is characterized in that the front end of the sheet is pressed between and.

(E) Action Based on the above configuration, the missing roller (1
When the circumferential portion (a) of (a) comes into contact with the sheet (S) stored in the sheet storage device (10) at a position slightly apart from the front end of the sheet (S) to start feeding, the front end of the sheet is , The separation pad (2) by the protruding portion (c) of the cam-shaped member (15)
Pressed against. Then, even when two sheets are fed at the same time, the two sheets are separated between the protruding portion (c) of the cam-shaped member (15) and the separation pad (2), That is, there is a gap between the upper sheet and the lower sheet, and then the upper sheet is sent out by the circumferential portion (a) of the missing circle roller (1a), so that the upper sheet and the lower sheet can be reliably separated from each other. The lower sheet is separated and the sheets are reliably fed one by one.

Further, when the sheet is not fed, the cutout portion (b) of the cutout roller (1a) and the separation pad (2) facing the cutout portion are separated by an auxiliary member (16) so that the circumference of the cutout roller is reduced. The wear of the part (a) is reduced.

The reference numerals in the parentheses are for the purpose of contrasting with the drawings, but do not limit the configuration of the present invention in any way.

(F) Example Hereinafter, an example of the present invention will be described with reference to the drawings.

The sheet feeding device M, as shown in FIG. 1 and FIG.
It has a truncated circle roller 1a, a cam 15, an auxiliary roller 16 and a separation pad 2, a part of the circumference of which is cut off, and the roller 1a and the cam 15 are shafts axially supported by a machine body (not shown). 3 and the auxiliary roller 16 is rotatably supported by the shaft 3. And the separation pad 2 is
In addition to forming a sheet conveying path, it is provided at the front end of the lower guide plate 6 among the lower guide plates 5 and 6, and is pressed against the truncated circle roller 1a by a spring 7 at a predetermined pressure and the truncated circle roller 1a. It is biased into frictional contact. Also,
A cassette 10 for accommodating the sheet S is arranged near the roller 1a, and the cassette 10 has a double bottom. Further, the sheet S is configured so as to be urged upward by the middle plate 9 and the middle plate pushing-up device 11 that form the double bottom of the cassette 10 and contact the missing circle roller 1a. The intermediate plate lifting device 11 includes a spring 11a and a shaft 1.
1b, a pressure plate 11c, and an abutting portion 11d, and the abutting portion 11d is configured to obtain a force for pushing up the intermediate plate 9 by the spring force of the spring 11a. Also,
A pair of registration rollers 13 is arranged downstream of the upper and lower guide plates 5 and 6, and the pair of rollers 13 holds the sheet S separated and fed by the sheet feeding device M to the downstream side. It is configured to be transported.

On the other hand, the truncated circle roller 1a has a circumferential portion a and a cut portion b obtained by cutting a part of the circumferential portion, and the circumferential portion a (range from the rotational direction point A to the point B)). Then, the auxiliary roller 16
It has a larger diameter, and has a smaller diameter than the auxiliary roller 16 at the cutout portion b (correctly, in the range from the rotational direction points C to F). Further, the auxiliary roller 16 has a constant diameter larger than the cut portion b and smaller than the circumferential portion a,
Moreover, the cam 15 has projecting portions c and c'that have a larger diameter than the truncated circle roller 1a and the auxiliary roller 16 at the connecting portion between the circumferential portion a and the cutout portion b. It has a shape that smoothly connects with the circumferential portion a. That is,
From the point A to the point B, the missing circle roller 1a, the auxiliary roller 16,
The diameter of the cam 15 is reduced in this order, and the points B to C
Up to the cam 15, the missing roller 1a, and the auxiliary roller 16 in that order.
The auxiliary roller 16 and the truncated circle roller 1a are formed in this order in a small size, and from the point D to the point E, the auxiliary roller 16 and the cam 1 are formed.
5, the truncated circle roller 1a is formed in this order, and from point E to point F the cam 15, the auxiliary roller 16, and the truncated circle roller 1 are formed.
It is formed in the order of "a", and from point F to point A, the cam 15, the missing circle roller 1a, and the auxiliary roller 16 are formed in this order.

Since the present embodiment is configured as described above, when a start key (not shown) is pressed, a motor (not shown) rotates,
The rotation of the motor is transmitted to the shaft 3. Then, the truncated circle roller 1a fixed to the shaft 3 and the cam 15 rotate, so that the uppermost sheet S on the cassette 10 is slightly separated from the leading end thereof, as shown in FIG. , Missing circle roller 1
Feeding is started by contacting the circumferential portion a at a point A of a. At this time, the leading end of the sheet S is pressed against the separation pad 2 by the protruding portion c of the cam 15, so that even if two sheets are fed, a deviation may occur between the upper sheet and the lower sheet. The lower sheet is reliably separated by the separating pad 2 based on the feeding by the circumferential portion a of the round roller 1a after that, and the sheet S is only the uppermost sheet S without being double-fed. Be delivered. Therefore, for example, when the sheets S are double-fed by electrostatic attraction or the like, the second and subsequent sheets S come into contact with the separation pad 2 and stop, so that the sheets S are double-fed before the separation pad 2. Instead, the uppermost sheet S passes between the separation pad and the missing circle roller 1a (see FIG. 4). Further, the sheet S has a point A on the missing roller 1a.
The sheet is fed from the portion to the point B and abuts the contact portion of the registration roller pair 13 to form a loop (see FIG. 5). Then, when the registration roller pair 13 starts to rotate, the sheet S receives the advancing input to the roller pair 13 by a loop, enters the contact portion of the roller pair 13, and is sandwiched by the roller pair 13. Transported downstream (6th
Figure). At this time, the rear end of the sheet S is sandwiched by the auxiliary roller 16 and the separation pad 2, but the roller 16 is rotatable, so it is lightly rotated together with the sheet S. Even if the second and subsequent sheets S are attracted to the first sheet S by electrostatic attraction, the leading ends of the second and subsequent sheets S contact the auxiliary roller 16 and the separation pad 2. Stop and do not double feed. Then, the first sheet S is conveyed downstream by the registration roller pair 13, and when the start key is pressed again, the second sheet S is fed by the same operation, and the following sheets S are also fed. The same operation is repeated.

Since the cam 15 smoothly connects from the outer diameter of the auxiliary roller 16 to the circumferential portion a at the connecting portion (F-A) from the cutout portion b of the lacking circular roller 1a to the circumferential portion a, The leading edge of the sheet is surely guided on the separation pad without causing a step portion due to the dimensional difference between the outer diameter of the roller and the outer diameter of the auxiliary roller 16.

Further, since the feeding roller 1a is cut out, as shown in FIG. 7, in the manual feed mode, the manual feed sheet S ′ is inserted on the sheet S from between the cutting portion b and the sheet S on the cassette 10. Then, the sheet S'is detected by a manual feed sensor (not shown), and the missing circle roller 1a and the cam 15 start rotating. Then, as shown in FIG. 8, the circumferential portion a of the missing circle roller 1a comes into contact with the manual sheet S'before the sheet S, so that the roller 1a
Around the point A, the peripheral portion a of the sheet engages with the sheet S ′ to feed the sheet S ′. At this time, even if the sheet S of the cassette 10 is on the separation pad 2, the sheet S is not
The protruding portion c of 5 makes contact with the separation pad 2 to stop,
It is not fed before the pad 2.

Further, in this embodiment, the missing roller 1a and the auxiliary roller 16
Although the separation pads contacting with and are made of the same member, the separation pads of the portions where the truncated roller 1a and the auxiliary roller 16 contact may be separation pads made of different materials.

(G) Effect of the Invention As described above, according to the present invention, the cam-shaped member presses the leading end of the sheet to the separation pad when the truncated circle roller contacts the sheet, so that the double feeding of the sheet is surely performed. Can be prevented.

Further, when the sheet is not fed, the auxiliary member separates the truncated roller from the separation pad, so that wear of the circumferential portion of the truncated roller can be reduced, and further, the registration roller arranged on the downstream side. Since the carrying force of the carrying section such as the above can be set to be small, the apparatus can be downsized and the cost can be reduced.

Further, the auxiliary member is composed of an auxiliary roller having a diameter smaller than the circumferential portion of the truncated roller and an outer diameter larger than that of the cut portion, and the cam-shaped member includes the outer diameter of the auxiliary roller and the circle of the truncated roller. If it is configured so as to be connected to the peripheral portion, a gap based on the dimensional difference between the outer diameter of the auxiliary roller and the peripheral portion of the missing roller is not formed, and at the start of rotation of the missing roller, the sheet front end is covered by the gap. It is possible to prevent the occurrence of problems such as the sheets being fed in a free state due to the portions, the sheets being fed in an overlapping state, and the leading edge of the sheets hitting the separation pad and bending.

Further, when the sheet is not fed, when the auxiliary member separates the sheet of the sheet storage device from the cutout portion of the truncated circle roller, the manual sheet can be inserted while being separated, so that the sheet of the sheet storage device can be inserted. In addition, you can also feed a manual feed sheet.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a sheet feeding device according to the present invention,
FIG. 2 is a perspective view showing a sheet feeding means according to the present invention, and FIGS. 3 to 9 are side sectional views showing an embodiment of the present invention.
FIG. 0 is a side sectional view showing a conventional example. 1a ... Missing circle roller, separation pad, 3 ... Shaft, 10 ... Sheet storage device, 15 ... Cam member, 16 ... Auxiliary means (roller), a ... Circumferential part, b ... Excision part, c ... Projection part, S ，
S '... sheet, M ... sheet feeding device.

Claims (3)

[Claims] 1. A sheet feeding device comprising a sheet feeding device and a separation pad, wherein the sheet feeding device feeds the sheets stored in a sheet storage device, and the separating pad separates the sheets one by one. In the feeding device, the sheet feeding means includes a cutting portion that is connected to a shaft that transmits rotation and that cuts a part of a circumferential portion, and the circumferential portion is stored in the sheet storage device. And a cut-out roller that comes into contact with and feeds the cut-out roller, and an auxiliary member that separates the cut-out portion from the separation pad when the sheet is not fed when the cut-out portion of the cut-out roller corresponds to the sheet storage device. A cam-like member that is connected to the shaft and has a portion that projects outward from the truncated circle roller in the vicinity of a position corresponding to a portion that moves from the cutout portion to the circumferential portion in the rotation direction of the truncated circle roller And, When the circumferential portion of the roller comes into contact with the sheet to start feeding, the protruding portion of the cam-like member presses the tip of the sheet between itself and the separation pad. Sheet feeding device. 2. The auxiliary member is an auxiliary roller rotatably supported by the shaft, and the outer diameter of the auxiliary roller is smaller than the outer diameter of the circumferential portion of the truncated circle roller, and When the sheet is started to be fed from the non-feeding state of the sheet, the auxiliary roller, the cam-shaped member, and the truncated circle roller are attached to the sheet stored in the sheet storage device. The cam-shaped member is formed so as to connect the outer diameter portion of the auxiliary roller and the circumferential portion of the truncated circle roller so as to contact each other in order. Sheet feeding device. 3. The auxiliary member, when the sheet is not fed,
The sheet accommodated in the sheet accommodating device is separated from the cutout portion of the truncated circle roller, and the manually fed sheet is inserted between the sheet and the truncated circle roller so that the leading end of the sheet comes into contact with the auxiliary member. The sheet feeding device according to claim 1.