JPH0733181B2 - Sheet material feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is to be loaded in a sheet material storage unit in an image forming apparatus such as a copying machine, a facsimile, a laser beam printer, a word processor, and other various sheet material using equipment. And set the sheet material (transfer paper, photosensitive paper, electrostatic recording paper,
The present invention relates to a claw separation type sheet material feeding device that sequentially separates sheets (cut sheets) of thermal paper, printing paper, printing paper, etc., and feeds them to a sheet material receiving unit.

(Prior Art) FIG. 12 is a partial vertical sectional side view of an example of a sheet material feeding device of a claw separation system.

1 is a sheet material cassette as a sheet material storage section,
It can be freely attached to and detached from the cassette receiving portion 2 of the copying machine main unit. Reference numeral 3 denotes a half-moon type (or circular) sheet feeding roller as a feeding rotating body disposed on the main body side, and is located above the tip of the cassette 1 when the cassette 1 is mounted on the cassette receiver 2. . Numerals 4 and 5 are a pair of sheet material guide plates and a sheet material relay transport roller of the sheet material transport system on the main body side, which are sequentially arranged on the downstream side of the front end portion of the mounting cassette 1 in the sheet material feeding direction.

In the sheet material cassette 1, 1a is a main body case of the cassette, 1b is an intermediate plate disposed in the case, and a pressure spring 1c.
It is supported so that it can swing vertically. Sheet materials S are stacked on the intermediate plate 1b and stored in the cassette 1. The stacked sheet material S on the middle plate 1b is regulated in the left-right width direction by a width regulating plate (not shown) disposed on the left and right sides of the middle plate 1b. Reference numeral 1d denotes a pair of left and right separating claw members which respectively engage with the left and right corners of the stacked sheet material S on the leading end side in the sheet material feeding direction to regulate the traveling direction and the upper surface of the sheet material.

The feeding roller 3 is always a half-moon cutout portion as shown by the chain double-dashed line.
3a faces downward, and is in a rotation stopped state in a rotation angle posture that is in non-contact with the upper surface of the stacked and stored sheet material S in the cassette 1.
Rotational force is transmitted through a clutch mechanism (not shown) or the like for each sheet feed start signal, and the sheet is driven clockwise one revolution.

The one rotation drive of the sheet feeding roller 3 is started, the circular arc surface portion 3b of the roller is brought into contact with the upper surface of the stacked storage sheet material S in the cassette 1, and the sheet feeding roller 3 applies the stacked sheet material S to the intermediate plate 1b. By rotating while pressing downward against the pushing force of the pressure spring 1c, the conveying force in the feeding direction acts on the uppermost sheet material S ₁ of the stacked sheet material S.

The fed uppermost sheet material S ₁ tries to move forward, but since the left and right corners on the leading end side thereof are constrained by the separating claw members 1d, the forward movement is suppressed, and therefore the feeding roller 3
With respect to the uppermost sheet material S _{1 following} the subsequent rotation of, the sheet material portion between the separating claw member 1d and the sheet feeding roller 3 resists the strength of the sheet material and is indicated by a two-dot chain line. S _^'1 ▼ it will deflect looped upward Ewan songs as. When the loop becomes larger than a certain size, the uppermost sheet material
The portion of S ₁ pressed by the separating claw member 1d passes over the member from the lower surface side of the member 1d, and naturally comes off to the upper surface side as indicated by the three-dot chain line {circle around ( ₁₎ } ^″ ₁ ^″ .

That is, only the uppermost sheet material S ₁ of the stacked sheet material S is released from the constraint of the separation claw member 1d, and _one sheet material is separated from the next and lower sheet materials.

The uppermost sheet material S ₁ separated one by one as described above is conveyed forward from the inside of the cassette 1 by the rotation of the feeding roller 3 and guided by the guide plate 4 to the intermediate transfer roller pair 5 to be intermediate transferred. The sheet is fed to a sheet material receiving unit such as an image forming unit of the main body device.

The arcuate surface portion 3b of the sheet feeding roller 3 separates from the surface of the uppermost sheet material S ₁ slightly before the end of one rotation and comes out of contact with the sheet material S ₁ , but by that time, the uppermost sheet material S _{1 1} , the leading end of the sheet reaches the intermediate transfer roller pair 5 and is intermediately connected, and the feeding of the uppermost sheet material S ₁ is continued even after the rotation of the sheet feeding roller 3 is completed and stopped. .

Thus, every time the paper feed roller is driven to rotate once by the paper feed start signal, the stacked sheet material S is separated and fed one by one from the top.

(Problems to be Solved by the Invention) In such a claw separation type sheet material feeding device, the contact pressure between the sheet feeding roller, which is a feeding rotating body, and the sheet material greatly contributes to the single sheet separating function, A delicate setting is required to reliably and stably separate one sheet.

That is, since the radius of the sheet feeding roller is constant in this type of conventional device, when the contact pressure between the sheet feeding roller and the stacked sheet material (sheet feeding pressure) is small (the diameter of the sheet feeding roller is small) The material conveying force becomes smaller, and the leading edge of the topmost sheet material may not get over the separating claw member, resulting in a paper feeding failure. The leading edge of the sheet material does not reach the conveying means, and the rotation of the sheet feeding roller is likely to end, resulting in a jam.

Further, when the contact pressure between the sheet feeding roller and the sheet material is large (the diameter of the sheet feeding roller is large), the sheet material conveying force becomes large and two or more sheet materials are simultaneously fed, that is, the weight of the sheet material is increased. Sending problems are likely to occur.

Further, when the sheet material is fed in a slanted state (skew feeding), the sheet material is skewed until it is corrected by a registration roller or a registration shutter provided in the sheet material conveying system on the main body side. Since they are transported as they are, there is a high risk that jam troubles will occur during this time.

The present invention also provides a sheet material feeding device of the claw separation type, which is configured so that it can always perform reliable and stable one sheet material separating and feeding without the above problems. With the goal.

(Means for Solving Problems) According to the present invention, a separation claw member that engages with the leading end side of a stacked sheet material to regulate the traveling direction and the upper surface of the sheet material, and contacts with the upper surface of the stacked sheet material and conveys the sheet material. This is a sheet material feeding device that sequentially separates and feeds the individual sheet materials of the stacked sheet material from the topmost sheet by a feeding rotation body that gives force. And a first contact area portion for contacting with the upper surface of the stacked sheet material and causing the leading end side of the uppermost sheet material to pass over the separation claw member to perform the first-stage transport movement necessary for separating one sheet. , Then the 1
2 with a second contact area portion that contacts the surface of the uppermost sheet material in the separated state and causes the leading end portion of the sheet material to carry out the second stage transport movement necessary to reach the next transport means.
And a contact pressure with the sheet material in the first contact area portion of the feeding rotary member is set to be smaller than a contact pressure with the sheet material in the second contact area portion. When a sheet material that has been separated and fed one sheet is freely moved in and out of the sheet material conveying path until it reaches the next conveying means, when the sheet material is conveyed and moved in the first stage described above. Is a control means for receiving the leading end of the sheet material separated and fed under the control of the entry state and regulating the sheet material to form a curved loop portion of the sheet material with the first contact region portion of the feeding rotating body. And the release of the curved loop portion of the sheet material and the retracting operation of the restricting means are sequentially performed until the sheet material is conveyed and moved in the second stage. Sheet material feeding device.

Is.

(Operation) A. That is, according to the present invention, the feeding rotating body is provided with the first and second contact area portions which come into contact with the upper surface of the stacked sheet material in order intermittently. (1) Stacked sheet material For releasing only the uppermost sheet material of the sheet from the restraint of the separating claw member to bring one sheet into a separated state.
The sheet material conveying / moving function of the second stage, and (2) the sheet material conveying / moving function of the second stage for reaching the next conveying means and relaying the sheet material in the state of separating one sheet are shared. Since it is configured to be executed by the first embodiment, the purpose is to separate one sheet material, the purpose is to move the sheet material in the first stage by the first contact area portion, and the purpose is to carry the separated sheet material. It is possible to set the sheet feeding pressure in the second-stage conveyance movement of the sheet material by the contact area portion to an appropriate pressure independently of each other.

In other words, it is possible to set the sheet feeding pressure at the first stage to be small so that only the uppermost sheet material can be reliably and stably separated from the second and lower sheet materials without causing a double feeding trouble. It is possible to set the sheet feeding pressure at the second stage to a large value so that the sheet material after separating one sheet can be reliably and stably conveyed to the next conveying means without causing insufficient conveyance due to slips or the like, and the state of intermediate transfer can be achieved. Can be secured. In this case, when one sheet material is normally separated in the first-stage conveyance movement of the sheet material, even if the sheet feeding pressure at the next second-stage conveyance movement is strong, the sheet material of the next rank or lower is separated by the separation claw member. Since it is restrained, the trouble of double feeding of sheet materials does not occur at this stage.

Therefore, in the claw separation type sheet material feeding apparatus, it is possible to always perform reliable and stable single sheet material feeding with high reliability.

B. First sheet material by the first contact area portion of the feeding rotating body
The leading edge of the sheet material that has been released from the restraint of the separating claw member in the stepwise transport movement and separated into one sheet is received by the sheet material leading edge regulating means which is controlled to enter the sheet material transporting path at that time. Further movement is restricted. Then, until the contact between the first contact area portion of the feeding rotating body and the sheet material surface is completed and then the second contact area portion starts contacting the sheet material, the feeding rotating body is the sheet material. Since it is not in contact with the sheet material and both sides of the sheet material are pressed between the side pad and the width regulating plate,
The skewed posture is naturally corrected even if the sheet material separated by the stepwise transport is unbalanced or the feeding pressure balance on the left and right sides is unbalanced and the sheet is transported in the skewed state. It

Since the sheet material front end regulating means is controlled to retract from the sheet material conveying path before the second stage conveying movement by the second contact area portion of the feeding rotating body is started thereafter, the skewed sheet material is corrected. Is conveyed to the next conveying means, and the jam trouble due to the skew conveyance of the sheet material is eliminated.

In addition, by the above-mentioned sheet material front end regulating means, the first sheet material
Since the front end position of the sheet material after separating one sheet by the stepwise transfer movement is always substantially constant, the feeding amount of the sheet material by the second step transfer movement is stable, and the sheet material is always secured to the next conveying means. Can be delivered to.

(Embodiment) <Embodiment 1> (FIGS. 1 to 7) Components and parts common to those of the apparatus shown in FIG.

1 to 3 are operation process diagrams, FIG. 4 is an enlarged side view of a sheet feeding roller, and FIGS. 5 to 7 are a perspective view, a plan view, and a transverse sectional view of a sheet material cassette, respectively.

Reference numeral 30 is a paper feed roller as a feeding rotary member, and a rotational force is transmitted via a clutch mechanism or the like (not shown) for each paper feed start signal, and is driven to rotate clockwise about the shaft 30a once. In the present embodiment, the first and second arc surface portions which intermittently contact the upper surface of the stacked sheet material S in one rotation process. It is a two-way-shaped roller provided with.

First arc surface Is a first contact area portion for carrying out the first-stage conveyance movement required for the leading end side of the uppermost sheet S ₁ of the stacked sheet material S to get over the separation claw member 1d to be in a single-separated state. Yes, second arc surface Is a second contact area portion for carrying out the second-stage transport movement required to reach the next-stage transport means 5 of the uppermost sheet material S ₁ in the separated state.

First arc surface The length of the arc is so long that the tip of the uppermost sheet material S ₁ of the stacked sheet material S can be passed over the separation claw member 1d and separated into one sheet by the contact rotation of the arc surface portion.

Second arc surface part The arc length is tentatively the first arc surface part Even if the single-sheet separation / feeding due to 1 fails, the sheet material that has failed to be separated is separated into one sheet, and the sheet material is sufficiently long to reach the next conveying means 5.

Also the first arc surface Radius r ₁ (Fig. 4) is the second arc surface Radius smaller than the radius r _{2 of} the first arc surface Contact pressure (paper feeding pressure) P ₁ between the stacking sheet material S and the second arc surface The relationship of the contact pressure P ₂ between the stack sheet material S and the stacking sheet material S is P ₁ <P ₂ . That is, the first arc surface portion The contact pressure P ₁ between the stacking sheet material S and the stacking sheet material S is relatively small so that only the uppermost sheet material S ₁ can be reliably and stably separated from the second or lower sheet material without causing double feeding trouble. The pressure is set and the second arc surface is The contact pressure P ₂ between the stacked sheet material S and the stacked sheet material S is relatively suitable for reliably and stably arriving the sheet material after separating one sheet up to the next transporting means 5 without causing insufficient transport due to slips or the like. A large pressure is set independently of the contact pressure P ₁ .

Reference numeral 30b denotes an arc member made of a material having good slidability (for example, POM) provided concentrically and integrally with the above-described two-sided feeding roller 30, and the first linear cutout portion ▲ ▼ of the feeding roller 30 is provided. In position. Its radius r ₃ is the first arc surface A little smaller than radius r ₁ .

Reference numeral 40 designates a shutter plate as a sheet material front end regulating means arranged in the middle of a sheet material conveying path leading to the conveying roller pair 5 which is the next conveying means for the separated sheet material, and is constituted by an electromagnetic solenoid-plunger 41. The state of being moved up and down to enter the sheet material conveyance path between the upper and lower guide plates 4 through the slit hole 4a provided in the lower guide plate 4, and the state of going down below the lower guide plate 4 to the outside of the conveyance path. It is controlled to switch to the state in which it is turned on.

FIG. 1 shows the state of the apparatus before the start of sheet feeding, and the sheet feeding roller 30 has a first arc surface portion. Is facing right and the second arc surface Is directed to the left, and the first linear notch portion {circle over (2)} between them is stopped in an angular posture in which the upper surface of the stacked sheet material S faces in a non-contact manner. At this time, the upper surface of the stacked sheet S is regulated by the upper surface of the stacked sheet S contacting the lower surface of the arc member 30b.

The power supply to the electromagnetic solenoid-plunger 41 is cut off, and the shutter plate 40 is in the retracted state.

When the clockwise rotation of the paper feed roller 30 is started based on the paper feed start signal, the electromagnetic solenoid-plunger 41 is energized and the shutter plate 40 enters the sheet material conveying path. Is switched to and held. And paper feed roller
First arc surface portion which is the first contact area portion of 30 Rotates downward to contact the upper surface of the stacked sheet material S with the above-mentioned contact pressure (paper feed pressure) P _{1 to} rotate the stacked sheet material S to the uppermost sheet material S ₁ in the first stage conveyance movement. The force acts to reliably and stably separate the sheet material S ₁ into one sheet. Since the circular arc member 30b is made of a material having a good slidability as described above, the circular arc member 30b is slid on the upper surface of the sheet and rotated, so that the member does not feed the sheet. The upper surface of the stacked sheet S is the first arc surface portion by the member 30b. Is maintained at a constant position level until the point a contacts the upper surface of the stacked sheet S, and the point a acts so as not to contact the upper surface of the stacked sheet S due to a sudden pressure. Eliminates instability and reduces pressure fluctuations during paper feeding.

The leading end of the uppermost sheet material S ₁ that has been separated by one sheet, has passed over the separation claw member 1d, and has protruded and moved forward of the cassette 1 is caught and received by the shutter plate 40. Figure 2 shows the first arc surface 3 shows the state in which the tip end of the separated sheet material S ₁ has abutted against the shutter plate 40 and is received by the shutter plate 40 after the contact rotation with respect to the uppermost sheet material S ₁ is completed. In this case, the first arc surface portion even after the front end of the sheet material S ₁ is received by the shutter plate 40. The feeding of the sheet material S ₁ by the
It is preferable that a loop is instantaneously formed in the sheet material portion between the sheet feeding roller 30 and the sheet feeding roller 30, as shown by the dashed line in FIG.

By receiving the front end of the sheet material by the shutter plate 40,
The leading end position of the sheet material after separating one sheet by the first stage conveyance movement of the sheet material is always substantially constant.

First arc surface part After the contact rotation with respect to the uppermost sheet material S ₁ is finished, the second rotation of the sheet feeding roller 30 causes the second arc surface portion. Until the sheet material S ₁ separated from the first sheet starts to contact the second linear cutout portion ▼.
The feeding force does not act on the uppermost sheet material S ₁ separated from the upper surface of the uppermost sheet material S ₁ in a non-contact manner. The stacked sheet material S, including the uppermost sheet material S ₁ which is separated by one sheet, has side pads 1g urged by springs 1e on both sides thereof.
Since there is a pressing force F (Fig. 6) between the width regulating plate 1f (Figs. 5 to 7) and the width reference plate 1f, which is the conveyance reference face of the sheet material, the first arc surface portion. The uppermost sheet material S ₁ separated by the contact rotation of 1 has a bad clawing, or the feeding pressure balance on the left and right sides is bad, and the sheet is skewed as shown by the chain double-dashed line in FIG. Even if the sheet is conveyed and moved in the first stage, the skewed posture is naturally corrected as shown by the broken line.

The electromagnetic solenoid-plunger 41 is energized in the second arc portion. Is cut off immediately before the sheet material S ₁ separated from the above-mentioned one starts to be contacted, and the shutter plate 40 is returned to the state of being retracted from the sheet material conveying path.

And the second arc part By the contact rotation of the sheet material, the second-stage transport movement of the sheet material S _{1 after} the separation of one sheet is performed with the contact pressure (paper feeding pressure) P ₂ described above, and the sheet material after the separation of the single sheet is the next stage. Is reliably and stably delivered to the pair of transport rollers 5 without slippage due to slippage or the like, is relayed to the pair of transport rollers 5, and is fed to a required sheet material receiving portion of the main body apparatus. FIG. 3 shows the second arc portion of the separated sheet material. 3 shows the state of the apparatus at the end of the second-stage transport movement by.

When the paper feed roller 30 makes one rotation and returns to the angular posture shown in FIG. 1 before the start of rotation, the rotation drive is stopped and the paper feed roller 30 enters a standby state until the next paper feed.

Thus, every time the paper feed roller is driven to rotate once by the paper feed start signal, the above operation cycle (FIGS. 1 to 3) is executed and the stacked sheet materials S are separated one by one from the top and fed. It

<Embodiment 2> (FIGS. 8 and 9) In the first embodiment, the shutter plate 40 is made to hang down from the upper guide plate side of the sheet material conveying path into the sheet material conveying path and to be pulled up and retracted. You can also

Further, as in the example of FIGS. 8 and 9, for example, a part of the lower guide plate 4 is freely tilted and tilted about the support shaft 42 to be in the standing posture as shown by the dashed line in FIG. 8 and FIG. Therefore, the shutter plate (4
It is also possible to function as a lower guide plate of the sheet material conveying path by causing the sheet material conveying path to function as 0), and by tilting it as shown in the solid line in FIG.

That is, a part of the lower guide plate 4 is normally urged counterclockwise about the support shaft 42 by the tension spring 43 to be held in a predetermined tilting angle posture received by the stopper 44 to serve as the upper guide plate. It functions as a pair of lower guide plates 4.

On the other hand, when the paper feed roller 30 starts to rotate once, the fan gear 45 fixed to the end of the paper feed roller shaft 30a and rotating integrally with the paper feed roller 30 can move back and forth in the forward and backward directions and is not shown. The arm 46 is moved forward by engaging with the tooth portion 46a of the arm 46 supported by the guide member of FIG.
The lower guide plate 4 is a tension spring 4 by the spring member 46b at the tip of 46.
Shutter plate (40) in a clockwise direction centered on the spindle 42 against 3
It stands up and is rotated. In the upright state, the paper feed roller 30 continues to rotate and the second arc portion of the paper feed roller 30 is rotated. Is held until just before starting contact with the upper surface of the stacked sheet material S, and then the engagement with the tooth portion 46a on the arm 46 side of the fan gear 45 is released so that the pressing force is released and the lower guide plate 4 again by the tension spring 43. It is returned to the tilt angle posture as.

<Embodiment 3> (FIGS. 10 and 11) The shape of the paper feed roller 30 may be three notches on the circumference as shown in FIG. 10 as long as it has at least two arc portions contacting the sheet material. It may be cut out at three or more places.

Further, the paper feed roller 30 may be in a form in which a friction rubber belt 30d is stretched on the outer peripheral surface of the roller base body 30c as shown in FIG.

(Effect of the Invention) As described above, according to the present invention, in the claw separation type sheet material feeding device, the contact pressure (feeding pressure) of the sheet material feeding rotator with the sheet material in the first contact region portion is increased. ) P ₁ is set to be smaller than the contact pressure P ₂ with the sheet material in the second contact area portion, that is, the contact pressure P ₁ with the sheet material in the first contact area portion of the sheet material feeding rotating body is When the topmost sheet material is separated by the separating claw member, the contact pressure P ₂ with the sheet material in the second contact area portion is set to a relatively small contact pressure that does not cause the sheet materials of the next and subsequent sheets to be double-fed. By setting the relationship of P ₁ <P ₂ so that the sheet material after separating one sheet has a relatively large contact pressure so as not to cause slipping, etc., a stable sheet can be obtained without causing separation failure. Material transfer is always performed, and the system is always reliable, stable and highly reliable, using the claw separation method. Door material feeding device is formed.

[Brief description of drawings]

1 to 3 are operation process diagrams of an embodiment of the apparatus, FIG. 4 is an enlarged side view of a sheet feeding roller, FIG. 5 is a perspective view of a sheet material cassette, FIG. 6 is its plan view, and FIG. FIG. 8 is a cross-sectional view of the shutter plate, FIG. 8 is a diagram of another configuration example of the shutter plate, FIG. 9 is a diagram of its tilting and rotating mechanism, and FIGS. FIG. 12 is a side view and FIG. 12 is a configuration diagram of an example of a conventional claw separation type sheet material feeding device. 1 is a sheet material cassette, 2 is a cassette receiver, 3/30 is a paper feed roller, Is a first and second contact area portion, S is a stacked sheet material, S ₁ is an uppermost sheet material, 1d is a separating claw member, 4 is a guide plate, 5 is a pair of intermediate transfer rollers.

Claims (1)

[Claims] 1. A loading claw member that engages with a leading end side of a stacked sheet material to regulate a traveling direction and an upper surface of the sheet material, and a feeding rotating body that comes into contact with the upper surface of the stacked sheet material and applies a transporting force. It is a sheet material feeding device that sequentially separates and feeds individual sheet materials from the topmost sheet material, and the feeding rotator contacts the upper surface of the stacked sheet material in the rotation driving process. And a first contact area portion for moving the leading end side of the uppermost sheet material over the separation claw member to perform the first-stage transport movement required for separating one sheet, and then the first contact area portion.
2 with the second contact area portion for contacting the uppermost sheet material surface in the separated state and for performing the second stage conveyance movement necessary for the leading end portion of the sheet material to reach the next conveyance means.
And a contact pressure with the sheet material in the first contact area portion of the feeding rotary member is set to be smaller than a contact pressure with the sheet material in the second contact area portion. When the sheet material that has been separated and fed by one sheet is freely moved in and out of the sheet material conveying path up to the next conveying means, when the sheet material is conveyed and moved in the first stage. Is a controlling means for receiving the leading edge of the sheet material separated and fed under the control of the entry state and regulating it to form a curved loop portion of the sheet material with the first contact region portion of the feeding rotating body. The release loop of the sheet material and the retracting operation of the regulating means are sequentially performed until the sheet material is conveyed and moved in the second stage. Sheet material feeding device.