JPS5974841A - Sheet feeder - Google Patents

Abstract

PURPOSE:To enable sheets to be fed without the occurrence of skew, by a method wherein at least a feed roller and a reverse roller are formed by 2 pairs of rollers which are disposed at an intervals in the direction extending approximately normal to a direction in which sheets are fed. CONSTITUTION:A shaft 15, an intermediate shaft 19, and a drive shaft 20 are rotatably supported to an arm 16 supported in a cantilever-like manner to a bracket 18 attached to a machine frame 17, and a pickup roller 14 and a feed roller 21, formed by two pairs of rollers 14a, 14b and 21a, 12b, are mounted to shafts 15 and 20, respectively. The shafts 15 and 20 are turned in linkage with each other through gear trains 22-24, and the drive shaft 20 is approriately turned by a drive source. Further, a reverse drive shaft 25 is rotatably supported to the machine frame 17, and the intermediate part of a pressurizing lever 26 is rotatably supported to said shaft 25. Further, a reverse shaft 27 having a reverse roller 30, formed by two rollers positioned opposite to said rollers 21a and 21b, is supported to the one end of the pressurizing lever 26.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sheet feeding device that separates and feeds sheets of paper stacked on a sheet feeding table one by one, such as a friction roller separation and feeding device.

In a copying machine or facsimile machine, for example, the first
As shown in the figure, there is a pick-a-rag roller 3 that presses against the top surface of a stack of paper sheets 2 stacked on a movable paper feed table 1, rotates in response to a paper feed signal, and feeds out the topmost paper, and A feed roller 4 is disposed downstream of the pickup roller and is driven to rotate in the paper feeding direction 6, and a feed roller 4 is disposed opposite to the feed roller 4 across the paper path and is driven to rotate in the direction of pushing back the paper. A reverse roller 5 that can be pressed against the feed roller 4 and the paper, between the reverse roller 5 and the paper 7, and between the paper sheets is provided so that the relationship between the coefficients of friction μf, μr, and μp is μf〉
A friction roller separation paper feeding device is known in which the material of each roller is selected so that μr>μp, and double-fed sheets are separated and fed one by one based on the difference in friction coefficient. In this case, for example, the reverse roller 5 is rotatably supported by the Iil+ 6 supported on the machine frame and rotatably supported by the pressure lever 7 f'L, which is engaged with the pressure lever 7. The reverse roller 5 is brought into pressure contact with the feed roller 4 by the action of the pressurized tin ring 80.

In this type of conventional paper feeding device, only one set of a backup roller, a feed roller, and a reverse roller is arranged, which poses a problem when paper of various sizes is used.

In other words, when the paper is arranged with the center as a reference, by arranging each roller along the center line, the skew of the paper can be corrected by means of guiding the paper, such as a cassette guide. In general, paper is often placed in a paper feeder with the end surface as the reference, and in such cases, it is difficult to select an appropriate position for each roller, and it is difficult to correct the skew. .

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the above-mentioned drawbacks of the conventional friction roller separation paper feeding device and to provide a paper feeding device provided with a simple device for reducing skew.

The details of the present invention will be explained based on examples shown in the figures.

In FIG. 2, a bundle of sheets 13 stacked on the bottom plate 12 of the holder 11 is pushed up by the bottom plate 12 so that its upper surface comes into pressure contact with the pickup roller 14.

As shown in Figures 2 and 3, the pickup roller]4
is fixed to a shaft 15VC, and the shaft 15 is rotatably supported by an arm 16. The arm 16 is fixed or, if necessary, swingably mounted on a platen 8 attached to the machine frame j7.

An intermediate shaft 19 and a drive shaft 2o are supported on the arm 16, and a feed roller 21 is fixed to the drive shaft 20. The drive shaft 20 is driven by a drive device (not shown).

A food f-dog gear 22 is fixed to the drive shaft 20, and a big Anglow 23 is fixed to the shaft 15, and both gears 22 and 23 are in mesh with each other via an intermediate gear 24, and the intermediate gear 24 rotates at the intermediate shaft ]9. freely supported.

The feed roller 2] and the pickup roller 4 are rotated synchronously by the rotation of the drive roller 20. By selecting the diameter of each roller 14.2) and the number of teeth of each gear 22, 23.24, the paper can be Sent at a constant speed.

A reverse drive shaft 25 is rotatably supported on the frame 17 and driven by a drive device (not shown). As shown in FIG. 4, the center portion of a pressure lever 26 is rotatably supported on the reverse drive shaft 25. As shown in FIG.

A groove 28 is formed at one end of the pressure lever 26, and the bearing 2
9 is removably attached. A reverse shaft 27 is rotatably supported on the bearing 29, and the reverse shaft 27
A reverse roller 30 is fixed to. II. A reverse gear 3] is rotatably supported on the hearth shaft 27, and a reverse drive gear 32 that meshes with the reverse gear 3J is fixed to the reverse drive shaft 25.

A pressurizing shaft 33 is attached to the other end of the pressurizing lever 26, and one end of a pressurizing gooseberry/gum 34 is locked to the pressurizing shaft 33. At the other end of the pressurized gooseberry/gum 34 is a machine frame 17.
&? : Directly or indirectly locked. Pressurized currants/
The strength of the gear 34 is selected so as to apply a predetermined pressure to the reverse roller 30i and the feed roller 2.

The pickup roller 11, the feed roller 21, and the reverse roller 30 are arranged as two rollers 14a, 14b, and 21a arranged at predetermined intervals.
b, and 3oa and 30b, the big unlow 7]4a, the feed roller 21+z, and the second birth roller 30α are one set, and the pick an's roller 14b
and feed roller 2]b and reverse roller 3ob, (
! : A total of two roller sets are provided as the t1 set.

Two roller sets 1d are arranged at a predetermined interval in a direction substantially perpendicular to the paper feeding direction ((), and the rollers of each roller set (]+4cc, 21 (1, 30a or 14b, 2)
b, 30b) are arranged on a straight line in the paper feeding direction (().

Figure 4 6 and reverse @ 27 is 1 Lucrimisoku 3
5 is attached, and the rotation of the reverse gear 3J is fixed at the reverse shaft 27V?- with the end surface touching the first hub 35 (Z and the first hub 35a) integrally formed.
? :.

Both hubs 35α, 35b Ic'! are located on the outer peripheries of the second hub 35b and both hubs 35a and 35b. The coil spring 35c is wound in a contracted state with a certain pressure, t, B.
It is configured. When a torque greater than the smaller of the torques due to the frictional force between the coil spring 35c and the first hub 35α or the second hub 35b is applied to the reverse shaft 27, that is, the reverse rollers 30a, 30b, the coil spring 35c and the circumferential surface of the first hub 35a or the second hub 35b, and the rotation of the reverse gear 31 is not transmitted to the reverse shaft.

Pin edge lug rollers 14a, 14b, feed roller 2]a, 21b, reverse rollers 30a, 30b
Each of these is composed of a hub fixed to a shaft and a rubber ring attached to the circumferential surface of the hub.

1" F. On the other hand, the reverse roller 30 receives a rotational force in the direction of sending the contacting paper back in the opposite direction, that is, reverse rotation, by the reverse gear 31 which is constantly driven to rotate, via the torque limiter 35.

Due to the rotation of the pickup roller 14 and the feed roller 21, the paper rises to the pressure friction force of the pickup roller 14, and is sent out from the pickup roller 11. The paper is further fed all the way between the feed roller 2J and the reverse roller 30. At that time, if there is only one sheet of paper, the paper is moved to the feed roller 2.
1 and the reverse roller 30, the paper is given a feeding force by the frictional force of the feed roller 21, and at the same time, a returning force is given by the frictional force of the reverse roller 30. IC) The torque applied to the reverse roller 30 by the Lucrimisotor 35 is the torque applied to the feed roller 2.
Since the torque n is set smaller than the torque caused by the torque limiter 35, the reverse roller 3o follows the paper and rotates due to the torque of the feed roller 2J without causing any slippage between the paper and the first hub 35α of the torque limiter 35. A relative slip rotation occurs between the second hub 35c and the second hub 35c.

When two sheets of paper are fed double, as described above, the friction coefficient μf between the feed roller 21 and the paper is larger than the number of friction threads μp between the sheets, and the friction between the reverse loaf 30 and the paper is larger than the friction thread number μp between the sheets. Since the coefficient μr is selected to be larger than μp, the upper paper that is in direct contact with the feed roller 21 is fed as it is due to the frictional force of the feed roller 2j, and the lower paper that is in direct contact with the reverse roller 30 is fed by the reverse roller. The frictional force caused by 30 causes slipping between the overlapping sheets, which reliably prevents two sheets from being sent out at the same time.

In this case, the torque limiter 35 is set so that it can transmit to the reverse roller 30 enough torque to return the lower sheet against the frictional force between the sheets.

If there are two or more sheets, the bottom sheet is sent back in order, and the reverse roller 30 is rotated following the feed roller 21 only when only the top sheet is left.

The torque limiter 35 is not limited to example 1c in the figure, but has a structure in which it is fixed to the reverse gear 31i1J perspective shaft 27 and transmits power to the reverse shaft 27 and the two reverse rollers 14α and 14E through the torque limiter 35, respectively. Also, a torque limiter can be interposed between the reverse drive shaft 25 and the reverse drive gear 32.

By providing two sets of feed rollers and reverse rollers spaced apart in a direction perpendicular to the paper feeding direction, the effect on paper skew is as follows.

()) When fC is used as a standard for vertically feeding 86-size paper.

In FIG. 5, the distance between the rollers (between 14α and 14b and between 30α and 3Ob) is F3, and the distance from the paper reference side edge surface to the 10th roller (the right roller in the example in the figure) near the reference side edge surface is tl. The distance from the 10th roller to the center point 0-1 between the two rollers is defined as 'f:t2.

Furthermore, the feed force of the 10th roller is Fl, the feed force of the other roller, that is, the 20th roller, is F2, the resistance force of the 10th roller is fl, the resistance force of the 20th roller is F2, and the roller's resistance force against the paper is The pressure is P, respectively, 1) The frictional force between the 20-layer and the paper is -tn, μprl, μpr2, from the line extending in the feeding direction passing through the center point O to the 86 size on the right side of the figure. Let the weight of the paper be m1 and the weight on the left side be m2. Furthermore, when A4 size paper aligned with the reference side edge is fed horizontally, the weight of the paper on the right side of the line passing through the center point 0 and extending in the feeding direction is defined as the electric switch eM2 of the paper on the left side of M1. Here, only the moment due to the two rollers (calculating the skew due to C is as follows: (i) For A4 size horizontal feeding, P, = P, , μprl = ppr2, so Fl:
F2-Plμpr1f1= +PI0M, )μpI)
1 f2-(P,, 10M,, ) μpp2 where μpI)], μpp2 is the coefficient of friction between the sheets, F
1) I)]-μpp2 Therefore, f 2 ""
CP + 10M2) μpp1 10th-ra feeding force is F 1 f 1-P IpprIIP + + M+
)l'pp1 The feeding force of the 20th -ra is F2-f2°P + ppr 1 (P + 10M2
) μpp' The moment around the point O is Mo+= [F+ f+ )12 (F2 F2
)A2-(M2-M1]μppJ-A2〉ol','M
2) M,) If the paper density is ρ, then A4 size paper is 297
Since the force is 210m, M2-ρX 210X(297-t+A2)M
□=ρX 2]0 ×C1□ +t2) Therefore, M2− M
,=ρxz1o X(297-zt,-zt2)>0
Therefore, 148.5 > lr 1t2...(1)(ii
') In the case of B6 size feed, the feed force of the 10th ring is F+ f+=P+μprl (P++m+) μpp
]The feeding force of the 20th-ra is F"2 F2"'PI/4prl 'CP++mz
) μpp1 The moment around point O is M 02 = (F+ It )A2- (F2-F
2) 12: (In2.-ml) pppl-12≧
If the density of 0 paper is ρ, 86 size paper is 182UX]
Since it is 28m, +712-ρX 182X (128-t+72)
m has ρx 382 x (t1+A2), so m2-1
nl ””ρX 182X (128-21+ 2t
2) Since ≧0, 91≧stone+t2...(2) As another condition, to ensure that the two rollers are in contact with the 86 size, IC stone>10...(3) tl +2t2 + (10X 2) < 128 therefore 4
+272 < 108...The condition (4) is added.

MOo by satisfying the above conditions (1), (2), (3), and (4).

1. to minimize Mo2. ．． Choosing a value of 12 provides the optimum value for the skew.

As example 1 11 = 12 ms A2 = 50 m
(t3=100 M) and set Mo1=pX2]0X(297-2X12-2X5
0)
Counterclockwise around the 0 point]...(5) Mo2-ρX 182X (128-2 mowing 2-2X50)
Xo, 5X50=1.8Kari04×ρf! -,) Counterclockwise around the 010 point) --- (6) (2) Based on horizontal feeding of 86-size paper.

As shown in FIG. 6, with reference to FIG. 5, B6 size paper is fed horizontally, and the skew due to the moment is calculated for the case of A4 size Jg paper being fed horizontally.

(i) Moment around point O in case of A4 size horizontal feed (same as (1) (+)) Mo
1-(M2-M+)μpplt2〉0M2 M+-ρ
X210X (2972t+212) > 0 therefore 14
8.5 >71 +4 ・・・・・・(1)(ii)1
In the case of 36-size horizontal feed, Mo3 = (m2-1n4)μppl ・t2+11
2-(Ill = ρX 128X(182-271-2
t2 ) < OMo3-ρ
t2...(7) Other conditions are tl>1.0...(3) t2>lO...(8) t1+2t2+ (IOX 2)< 182 Therefore, stone+
212 < 162... (9) or more (]),
(3) , (7) , (8) , Cs) to minimize Mo, , Mo2, that is, t +
'z, t, , t2 to maximize + t2
The first shift is the optimum value for skew.

This condition is shown in Figure 7, where the horizontal axis shows 1.
Taking the value of t2 on the vertical axis, condition (1) 'f: is satisfied in the range below straight line A, condition (3) is fully satisfied in the range to the right of straight line B, and condition The range above straight line C satisfies (7), the range above straight line E satisfies condition (8), and the range below straight line E satisfies condition (9). range. The range that satisfies all of the above conditions is the shaded range in FIG.

As example 2, t112 bar A2 = 50 173-] 0 noodles)
MO2=ρX 2]OX(297-2X62-2X50
)
0 ) Xo, 5X50 = -1,3 - We have explained the relationship between the horizontal feeding of A4 size sheets that tends to cause skew, but this is just an example. The roller position can be selected with consideration.

As mentioned above, the degree of sheet skew depends on the selection of the roller position, and in the above two cases, (5)>
Oo) > (1]) > (6).

However, in the case of actual feeding, the magnitude of the feeding force and various conditions are taken into consideration, and the rotational moment during feeding of the above degree is canceled out, so that practically no skew occurs. Therefore, in a sheet feeding device using a set of feed rollers and reverse rollers, the size of 4'-3-
The present invention ((
It becomes possible to improve it so that it is less likely to occur.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a conventional sheet feeding device, Fig. 2 is a front partial view of the device according to the invention, Fig. 3 is a plan view of related parts of the troller and pickup roller, and Fig. 4 is a reverse roller. Figure 5 is a diagram explaining the torque acting on the paper in 86-size vertical feed and A4-size horizontal feed, and Figure 6 is a plan view of the relevant parts in 86-size horizontal feed and A4-size horizontal feed. FIG. 7, which corresponds to FIG. 5, is a diagram showing the conditions for selecting the position of the feed roller in the case of FIG. 6 as an example. ]3... Sheet of paper 14.14a, 14b,...Pickup roller 2]
, 21a, 21b...Feed roller 30.30a
, 30b ... Reverse O-735 ... Torque limiter agent Patent attorney Takeshi Ito Procedural amendments June 9, 1982 Commissioner of the Patent Office Kazuo Wakasugi 1 Indication of case Patent application No. 180560 of 1980 2 Name of the invention Sheet feeding device 3 Relationship with the person making the amendment Patent applicant name (674) Rico Co., Ltd. -4 Agent address Kaji Kogyo Building, 2-32-4 Nishi-Shinbashi, Minato-ku, Tokyo
105 (433) 4564 Showa Date: Detailed Description of the Invention, Brief Description of the Drawings, Contents of Amendments to Drawing 7 (1) Description on page 17, line 12 of the specification of the present application: “It has become possible to .” became possible. The structure related to the reverse roller 30 may be modified from the example shown in FIG. 4 as shown in FIG. 8. That is, the reverse rollers 30a and 30b are rotatably supported by the reverse shaft 27, and each reverse roller 30a, 30b is drivingly connected to the reverse shaft 27 via the 1-lux limiter 35. Torque limiter 35 is reverse roller 30a
or a first hub 35 fixed or integrally formed at 3°b.
a and the reverse shaft 2 with its end surfaces in contact with the first hub 35a.
The second hub 35b fixed to 7 and both hubs 35a and 35b
The coil spring 35 is wound around the outer periphery of the hub 35a and 35b in a compressed state across both hubs 35a and 35b. A reverse gear 31 is fixed to the reverse shaft 27 (
and a reverse drive gear 32 that meshes with the reverse gear 31.
is fixed to the reverse drive shaft 25. In the example of FIG. 4, the reverse shaft 27 and the bar roller 30a,
30b is fixed, and the reverse gear 31 and the reverse shaft 27 are connected via the torque limiter 35, whereas in the example of FIG. The modification is that the reverse shaft 27 and the reverse rollers 30a, 30b are connected via a torque limiter 35. In the example of FIG. 8, there are two reverse rollers 30a and '30b.
Since the reverse rollers are independently affected by the torque limiter, the reverse direction of each reverse roller is individually determined by the torque limiter. There is an advantage that a large skew 2 does not occur even if the second sheet of paper is at the nip position. ” I am corrected. (2) The statement “Diagrams shown” on page 18, line 2 of the specification of the present application is replaced with “
The figure shown in Figure 8 has been corrected as Plane J showing a modification of Figure 4. 3) Add Figure 8. Procedural amendment August 160, 1980 Director of the Japan Patent Office Kazuo Wakasugi 1 Indication of the case 1980 patent Junko No. 180560 2 Name of the invention Sheet feeding device 3 Person making the amendment Relationship to the matter Patent To the applicant Issue I
X Address Name (674) Ricoh Co., Ltd. 4 Agent address Kaji Kogyo Building, 2-32-4 Nishi-Shinbashi, Minato-ku, Tokyo Telephone (433) 4564 Postal code 10
5 Name Patent Attorney (6313) Takeshi Ito
6. Claims and detailed description of the invention in the specification subject to amendment. 7. Contents of amendment 1) The description of the scope of claims in the specification of the application will be corrected as shown in the attached sheet. 2) The statement ``tobar roller'' on page 3, line 4 of the procedural amendment dated June 9, 1988 is corrected to [tori/\-sroller.'' 3) The statement "reverse torque is torque" on page 3, line 14 of the same page has been corrected to "reverse torque is torque." Attachment 2, Claims (1) A feed roller that is rotationally driven in one direction at a predetermined timing, and the feed roller that is rotationally driven in the direction of returning and feeding the sheet with a determined torque by a shaft that is continuously rotationally driven. In a friction roller separation sheet feeding device having a reverse roller that is pressed into contact with the feed roller, and a pickup roller that is arranged upstream of the feed roller in the sheet feeding direction and rotationally driven in synchronization with the feed roller, at least the feed roller and the reverse roller A sheet feeding device comprising two sets of rollers spaced apart from each other in a direction substantially perpendicular to the sheet feeding direction. (2) The foot roller, the reverse roller, and the pickup roller are each composed of two sets of rollers arranged at intervals in a direction substantially perpendicular to the sheet feeding direction. The sheet feeding device according to item 1. (3) In order to set the drive torque of the reverse roller, one torque limiter is provided between the shaft that drives the reverse roller and the means for driving the shaft. The sheet feeding device according to item 2.

Claims (1)

[Scope of Claims] (J) At a predetermined timing, a torque 4 determined by a rotationally driven feed roller and a continuously rotationally driven shaft C is rotated in a direction from sheet return 1 to feed direction, I @
a friction roller separation roller having a reverse roller which is moved and presses against the feed roller; and a big ag roller which is arranged upstream of the feed roller in the sheet feeding direction (C) and is rotationally driven in synchronization with the feed roller. In the sheet feeding device, at least a feed roller and an IJ
7 The sheet feeding device according to claim 1, comprising two sets of rollers spaced apart. (3) For setting the driving torque of the reverse roller. The sheet feeding device according to claim 1 or 2, characterized in that one torque limiter is provided between the shaft that drives the feed roller and the means that drives the feed roller. 4) To set the driving torque of the reverse roller 2
The notebook according to claim 1 or 2, characterized in that a torque limiter is provided between each of the reverse rollers and the shaft that drives the rollers. Feeding device.