JPS641303Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sheet separating device, particularly a sheet separating device suitable for electrophotographic copying machines and the like.

An example of such a sheet separating device is shown in FIGS. 1 and 2. That is, in these figures, the stacked sheets S are placed on the upper surface of the placing plate 1. The mounting plate 1 is arranged in a horizontal position and has a notch 1a formed therein. Feeding roller 2
has its upper outer periphery protruding from the notch 1a and is supported rotatably in the direction of the arrow. The vacuum tank 3 attached to the back of the mounting plate 1 is
The blower 4 is formed to surround the feeding roller 2.
This allows the air above the placement plate 1 to be sucked in through the gap between the notch 1a and the feed roller 2, thereby bringing the bottom sheet _S1 into close contact with the feed roller 2. A normal rotation roller 5 is disposed at the advancing side end (left side in the drawing) of the placing plate 1 in the sheet conveyance direction in such a manner that its upper outer periphery protrudes from the placing plate 1 . The normal rotation roller 5 is made of rubber with a large coefficient of friction, and is used to further convey the bottom paper S ₁ fed by the feed roller 2 to the left in the figure, and is rotated in the direction of the arrow in the figure. . The gate plate 6 is arranged to be inclined at an acute angle in the sheet conveyance direction with respect to the placement plate 1, and the lower the sheet is, the more it is shifted toward the advancing side (to the left in the figure) in the sheet conveyance direction. The protruding piece 6b extending from the lower edge 6a of the gate plate 6 is made of a rubber plate and is adapted to come into pressure contact with the normal rotation roller 5.
If the coefficients of friction between the sheet and the normal rotation roller 5, between the sheet and the protruding piece 6b, and between adjacent sheets are μ5, μ6b, and μS, respectively, then the relationship μ5>μ6b>μS is established. The materials of the circumferential surface of the normal rotation roller 5 and the protruding piece 6b are set so as to. Then, the normal rotation roller 5 and the protruding piece 6b
and constitute a separation means.

Now, when the sheet S is set on the mounting table 1 and the feeding roller 2 rotates, the sheet S moves to the left in the figure and collides with the gate plate 6, and the upper sheet is prevented from advancing by the gate plate 6. Then, the bottom sheet S ₁ and some of the lower sheets are sent to the separating means along with the bottom sheet S ₁ . The gate plate 6 serves to form the laminated sheet S into a fine step-like shape and at the same time to prevent the sheet from progressing. The lower sheet fed into the separating means is such that the lowermost sheet _S1 moves to the left in the figure by the rotation of the forward rotating roller 5, which has a large friction coefficient, and is gripped by a pinch roller (not shown); The upper paper of the lower paper _S1 is prevented from advancing by friction with the protruding piece 6b. Bottom paper S ₁
When the paper is caught by the pinch roller, the leading edge of the paper is detected and the drive of the normal rotation roller 5 is released. The normal rotation roller 5, which rotates as the bottom paper _S1 is moved by the pinch roller, stops at the same time as the trailing edge of the paper passes. When the feeding roller 2 and the normal rotation roller 5 are connected as the same drive system, a one-way clutch is installed on each roller shaft to prevent the influence of the moving paper on the next paper. We are starting to eliminate this.

FIG. 3 shows another example of the conventional sheet separating device, in which the loading plate 1A is arranged at an angle and the feeding roller 2 (see FIG. 1) is omitted. . Since the sheet's own weight will cause it to slide on the upper surface of the loading plate 1A, there is a risk that it will not slide if the slope is not sufficiently steep, and if the slope is too steep, the sheet's own weight will push open the protrusion 6b at the bottom of the gate, impeding separation. There are drawbacks such as lack of reliability of the device.

Common disadvantages of the sheet separating apparatus shown in FIGS. 1-3 are as follows. That is, the second
As is clear from the figure (this figure is also a perspective view of the apparatus shown in Fig. 3), the number of sheets equal to the height of the gap H between the gate plate 6 and the mounting plate 1 is usually limited to the protrusion 6b. This inhibits its progress. Therefore, when the coefficient of friction between sheets increases, such as on a humid day, the protrusion 6 prevents the above number of sheets from following the movement of the bottom sheet by the feed roller.
There is a possibility that b alone cannot prevent the problem.

4 and 5 show a modification of the above example, and FIG. 4 shows a protrusion 6b used as a separating means.
(See FIG. 1) A type in which a blocking roller 5a is provided is shown. The blocking roller 5a is made of a friction member such as rubber, and may rotate in a blocking direction with respect to the sheet conveyance direction, or may be fixed. When it rotates, it generally rotates slightly in the direction of the arrow in the figure. FIG. 5 shows a type in which a weight 8 is placed on the upper surface of the laminated sheet S to apply a load instead of sucking the area around the feeding roller 2 with a vacuum.

Next, the function of the gate plate will be explained. That is, the gate plate plays the role of breaking up the sheets stacked in a block shape and the role of guiding the leading edge of the sheets. If the gate plate is arranged at an angle close to perpendicular to the placing plate, it is very effective in breaking the sheet, but it is hardly effective in guiding the sheet. This is especially bad if the sheet has curls.

6 to 8 show the state of contact between the front edge of the curled sheet and the gate plate. 6th
In the figure, if the front edge _S2 of the sheet is curled upward (face curl), the sheet is conveyed to the left in the figure, so it will eventually bend as shown by reference numeral _S3 . However, as shown by the broken line in FIG. 7, if the angle between the gate plate 6A and the mounting plate 1 is made smaller, the sheet will slide in without being bent. In the figure, a straight line perpendicular to the gate plates 6, 6A is drawn from the contact point M between the front edge of any sheet S and the gate plates 6, 6A,
Check whether these straight lines intersect with sheet S. If they intersect, the sheet S will be bent. In this case, the straight lines erected at the gate 6 intersect at point N, so the sheet S is bent at the gate 6. FIG. 8 shows a case in which the sheet is curled downward (back curl), and there is a possibility that the sheet tends to be wedged into the gap between the lower edge 6a of the gate and the placement plate 1 more than necessary, and may not be conveyed. . In this case, it is better to increase the angle of the gate plate 6 with respect to the mounting plate 1. Therefore, in conventional sheet separating apparatuses, the angle formed between the gate plate and the mounting plate is selected at a midpoint between the two, resulting in unreliable separation performance.

In addition, the sheet separation device proposed in Utility Model Publication No. 52-13740 was designed to overcome the rigidity (stiffness) of the sheet itself.
The sheets are separated using the Although this device achieves its intended purpose,
There are still doubts about the separation performance when feeding sheets whose stiffness does not fall within a predetermined range, that is, sheets whose stiffness is weak. In any case, in the conventional apparatus, a large conveying force is required to separate sheets that are in close contact with each other, so there is a problem that the sheets may be damaged or soiled.

The purpose of the present invention is to provide a sheet separating device that can solve the above-mentioned conventional drawbacks and can reliably and smoothly separate even curled sheets without bending and even tightly packed sheet bundles. be.

This purpose consists of a placing plate on which the laminated sheets that are conveyed from the bottom sheet are placed, and a chopping roller whose upper outer periphery protrudes from a notch formed in the placing plate to frictionally feed the bottom sheet. and a lower edge of the feed roller is positioned near the feed roller, so that when the front edges of the sheets collide, the lower the sheet, the more the sheet is positioned on the advancing side in the sheet conveyance direction. , a sheet separation device comprising a gate plate disposed at an angle with respect to the placement plate, the gate plate being located on the advance side in the sheet conveyance direction from a line passing through the center of the feeding roller and perpendicular to the placement plate. The roller is positioned so as to correspond to the lower edge of the feed roller and the feed roller that are adjacent to each other and not to fit between the roller end faces, and to a protrusion extending in a comb-like shape with a width smaller than the gap between the feeding rollers, and the dimension between the mounting plate and the protrusion is A;
When the dimension between the aforementioned mounting plate and the top of the outer periphery of the feeding roller protruding from this mounting plate is C,
A sheet separating device characterized in that each of the dimensions is set so that A<C holds, and the sheet fed between the feeding roller and the protruding piece is undulated in a direction perpendicular to the conveying direction thereof. It is achieved by doing so.

According to the present invention, the lower edge of the gate plate is
Since the feed roller is positioned on the sheet conveyance advance side from the center, and protrusions protrude from the lower edge on both sides of the feed roller, the sheet is transported by the adjacent feed rollers and the protrusions. Since the sheets are corrugated in a direction perpendicular to the conveyance direction, separation of the sheets is promoted and the sheets are reliably separated. Furthermore, due to the relationship between the dimensions between the protruding piece and the mounting plate and the height of the feeding roller protruding from the mounting plate, even if the sheet tries to get caught between the gate plate and the feeding roller, this Blocked by the protrusion, the lowest sheet can be fed by frictional force against the feed roller.

The illustrated embodiment will be described in detail below.

FIG. 9, FIG. 10, and FIG. 11 are a side sectional view, a front view, and an external perspective view showing the embodiment, respectively. In these figures, a stacked sheet S is placed horizontally on a mounting plate 11, and a cutout 11a is formed in a portion of the mounting plate 11. The feeding roller 12 is provided below the mounting plate 11, and has its upper outer periphery protruding from the notch 11a. Feeding roller 12
As can be clearly seen from FIG. 10, this is a so-called chopped roller whose effective roller circumferential surface is disposed intermittently along the axis of its support shaft. The vacuum tank 13 is fixed to the back surface of the mounting plate 11 and is formed to surround the feeding roller 12, and the pressure inside the vacuum tank 13 is maintained at negative pressure by the suction action of the blower 14 from the bottom. It is added. The lowermost sheet _S10 is pressed against the feeding roller 12 by this negative pressure and is given a large feeding force.

The gate plate 16 is disposed at an incline so that the lower sheets are more likely to be conveyed in the sheet conveying direction (to the left in FIG. 9) than the upper sheet conveying direction (to the left in FIG. 9). The lower edge 16a of the gate plate 16 is located to the left of the line perpendicular to the center of the feed roller 12 and at a suitable distance from the upper outer periphery of the feed roller 12.
In this case, a plurality of feeding rollers 12 are arranged on the same axis, and the protrusions 16b are also arranged at both ends in the axial direction and between the feeding rollers. The gap between the protrusions 16b and the mounting plate 11 is appropriately set depending on the paper quality. More specifically, the protrusions 16b
corresponds to the gap between the adjacent feed rollers 12, 12, and extends toward the mounting plate 11 in a comb-tooth shape so as not to enter between the end faces of the adjacent rollers. The protrusion 16b is formed with a width smaller than the dimension between the adjacent feed rollers, so as to ripple the sheet fed between it and the feed roller.

Gate plate 16, feeding roller 12, and mounting plate 1
1, downstream of the sheet separating device consisting of 1 and 2.
A sheet separating means 15 is arranged.

The separating means 15 is disposed between guides 17 and 18 provided on the advancing side of the sheet conveyance direction of the placing plate 11, and is composed of a combination of a lower normal rotation roller 15a and an upper reverse rotation roller 15b. . These rollers 15a and 15b are arranged alternately in a direction perpendicular to the sheet conveyance direction, with the normal rotation roller 15a rotating in a direction to feed the bottom sheet in the conveyance direction, and the reverse rotation roller 15b rotating in a direction to feed the bottom sheet. It rotates in a direction that touches the top surface of the paper and prevents it from being transported. The reversing roller 15b may be stopped.

The operation of this device will be explained.

When the laminated sheet S is placed on the upper surface of the mounting plate 11 and the rollers 12, 15a, 15b and the blower 14 are driven simultaneously by a paper feeding command, as the bottom sheet _S10 is frictionally fed by the feeding roller 12, The front edge of the sheet collides with the gate plate 16, causing the block-shaped stacked sheets S to collapse, and the lower part of the sheet behaves as if it bites into the gap between the lower edge 16a of the gate plate and the feeding roller 12.

However, since the sheets other than the bottom sheet _S10 do not contact the feed roller 12 and have a weak feeding force, the protrusions 16b prevent the sheets from moving forward and cause them to be bitten, as shown by the thin line in FIG. Nothing happens.

On the other hand, since the bottom paper S ₁₀ is in contact with the feed roller 12, the feeding force is large, and as shown by the broken line in FIG. It is conveyed while passing through. At this time, the lowest sheet _S10 is undulated in the transport direction as shown by the broken line due to the relative positional relationship between the protruding piece 16b and the feeding roller 12, and its advancement is prevented by the protruding piece 16b. Since an air layer is formed between the paper and the upper paper, the separation is more secure. If the sheets are thin, there is a risk of double feeding.
The second sheet separating device 15 completely prevents double feeding and separates and feeds only the bottom sheet.

If the sheet has a well-balanced thickness and size, or if it is thick like a card, the second sheet separating means is not required. Examples of such a sheet separating device with only one stage are shown in Figures 12 to 14.
As shown in the figure. In this case, the vacuum tank is also omitted, and it has the advantage of being lightweight and compact and applicable to specific paper types and sizes.

FIG. 15 shows the relationship between the gate plate 36 and the feeding roller 32. In this figure, C is the dimension from the mounting plate 31 to the top of the outer periphery of the feeding roller 32, A is the gap dimension between the gate plate protrusion 36b and the mounting plate 31, and B is the lower edge 36a of the gate plate. and D indicates the length of the protrusion 36b, respectively, and it has been experimentally determined that sheet separation is stable and reliable when these dimensions have the following relationship. It has been revealed. θ indicates the inclination angle of the mounting plate 36.

A = > B E ≒ C/2 θ = 1 to 80° Here, dimension C is generally about 1 to 4 mm, and dimension A is about 0.5 to 3 mm. Considering the curl of the sheet, the appropriate inclination angle θ is 30 to 60°. Dimension D is automatically determined once θ, A, B, and C are determined. However, these are only examples of each dimension, and the width, number, material, and shape of the feed rollers, the gap between adjacent feed rollers, and the gap between adjacent gate plate protrusions are also determined by the sheet size, thickness, sheet transport speed, etc.

By setting the relationship between the dimension C from the mounting plate 31 to the top of the outer periphery of the feeding roller 32 and the gap dimension A between the protruding piece 36b and the mounting plate 31 to be C>A, the following can be achieved. be effective. The laminated sheet placed on the placement plate 31 is lifted from the placement plate 31 by a dimension C and rides on the roller, and when it receives a feeding force, its leading end abuts against the gate plate 36. When the leading edge of the sheet rides on the roller, the close contact between the leading edges of the sheets is loosened to some extent, so when the leading edge of the sheet collides with the gate plate 36,
The lower the seat, the easier it is to go ahead. Therefore, only the lowest sheet of paper is transported. The sheet that collides with the gate plate 36 is guided downward by the dimension A, which is smaller than the dimension C, toward the mounting plate 31 by the protruding piece 36b, so that the sheet is reliably undulated. Forms a layer of air between it and the upper sheet. Therefore, the sheets can be separated from each other more reliably. If dimension A is larger than C, the problem remains that the sheet cannot be separated reliably because no waviness occurs in the sheet. On the other hand, the sheet whose advance is blocked by the gate plate 36 is not receiving enough feeding force to curve along the gate plate, so it cannot get between the protrusion and the feeding roller and does not wave. , easily forming a gap between the bottom paper and the bottom paper. That is, as above, C>
Since the relationship A is set and the gate plate is placed in front of the lowest paper, the laminated sheets being fed are unraveled from their leading ends, and reliable separation and feeding is performed.

Although it is of course possible to use a material with a high friction coefficient such as rubber for part or all of the gate plate protrusion, a stainless steel plate is generally used. Furthermore, the projection may be formed from a plastic plate.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing a conventional sheet separating device, FIG. 2 is a partially cutaway perspective view of the device, and FIG. 3 is a side sectional view showing a conventional device with an inclined mounting plate. Figures 4 and 5 are side sectional views showing another example of the conventional device, Figures 6 to 8 are diagrams explaining the relationship between the curl and the gate plate, and Figure 9 is a diagram showing an embodiment of the present invention. The side sectional view, FIGS. 10 and 11 are a front view, partially cut away perspective view, FIG. 12, and FIG.
3 and 14 are side sectional views, front views, and perspective views showing other embodiments of the present invention, respectively, and FIG. 15 is a diagram for explaining the relative positions of the gate plate and the feeding roller. 11, 21, 31... mounting plate, 12, 22, 3
2... Feeding roller, 16, 26, 36... Gate plate, 16a, 26a, 36a... Lower edge, 16
b, 26b, 36b... protrusion, S... sheet,
S ₁₀ ...Bottom paper.

Claims (1)

[Claims for Utility Model Registration] Placing plates 11, 21, 31 for stacking laminated sheets conveyed from the bottom paper S ₁₀ , and placement plates _11, 21 for friction feeding the bottom paper S 10. , 31, the upper outer periphery of which protrudes from the notch 11a formed in the feed roller 12, 22, 32, which is a chopped roller.
The lower edges of the feed rollers 12, 22, and 32 are located near the feed rollers 12, 22, and 32, so that when the front edges of the sheets S collide, the lower the sheet, the more the sheet is positioned on the advancing side in the sheet conveyance direction. In the sheet separating device, the gate plates 16, 26, 36 are disposed obliquely with respect to the placement plates 11, 21, 31.
2, 22, 32 passing through the center O of the mounting plate 11, 2
The lower edges 16a, 26a, 3 are located on the advance side in the sheet conveyance direction from the line orthogonal to 1, 31.
6a, and is located between the adjacent feeding rollers 12, 22, 32 and the feeding rollers 12, 22, 32 without intervening between the roller end surfaces, and the lower end edges 16a, 26a, Projections 16b, 26b, 36b extend from 36a toward the mounting plates 11, 21, 31 in a comb-teeth shape with a width smaller than the gap between adjacent feeding rollers, and the front The dimension between the writing plate 11, 21, 31 and the protruding piece is A, and the feeding roller 12, 22, which protrudes from the writing plate 11, 21, 31 and this placing plate,
When the dimension between 32 and the top of the outer periphery is C,
A sheet separating device characterized in that each of the dimensions is set so that A<C holds true, and the sheet fed between the feeding roller and the protrusion is undulated in a direction perpendicular to the conveyance direction thereof.