JPS5969328A - Paper feeder - Google Patents

Abstract

PURPOSE:To improve the reliability for the separation performance by rotatably supporting one edge of a separation roller in swingable ways and installing a separation roller at the other edge and pressing said roller onto a feed roller, in a paper feeder for a copying machine. CONSTITUTION:A separation roller 2 onto which a torque limiter 18 whose one edge is fixed onto a separation shaft 14 axially supported rotatably is installed at the left edge of the shaft 14, supported rotatably and in swingable ways within a prescribed range on the plane including the shaft of a feed roller at the right edge of the separation shaft 14. With such constitution, the relation between the pressing force PB of the separation roller 2 and a blank-form returning force TA is determined by each distance from a fulcrum 22 to a gear 15, bearing 24, separation roller 2, and the center of gravity of the shaft 14, namely l1, l3, l4, and l2, and the influence of the change with lapse of time can be eliminated. Thus, reduction of separation performance by the lapse of time can be prevented, and reliability can be improved.

Description

[Detailed description of the invention] Technical field The present invention relates to a paper feeding device used in a copying machine or the like.

Conventional paper feeding devices for copying machines, etc. have a feeder rotating in the paper feeding direction, and a paper path that is sandwiched in pressure contact with the feeder, and a constant torque H4 is applied in the opposite direction to the paper feeding force direction. When there is no paper between the rollers and when one sheet of paper is fed, the separation roller follows the separation roller and rotates without slipping with the feed roller or paper, or feeds two or more sheets. If a sheet of paper is fed between the pair of rollers, the torque of the separation roller overcomes the frictional force between the sheets and pushes the second and subsequent sheets back towards the paper feed tray, separating them and feeding them. 2. Description of the Related Art Frictional separation paper feeding devices are known in which only one sheet of paper in contact with a roller is fed into the machine.

The paper feeding device of this (7) method has a lower separation speed between the feed roller and the paper compared to a paper feeding device of the method in which the separation opening roller rotates in the opposite direction to the paper feeding force direction or is always stopped. There is no slippage, and the friction of the paper causes fuzzing and paper dust, and the associated "1-La friction 1? decrease in the coefficient, etc."
The fact that there is only one point is excellent.

By the way, conventionally, as shown in FIG. 2,
A spring 5 stretched between the thin end of the lever 4 and the machine frame presses the feed 7-ra 1, and also connects the gear \'6 provided on the separate lane Ron 1 cola 2 and the same 1111 to the lever 4's bottom 7. It was driven by the drive gear 8 installed in the 1711I7.

In this configuration, 1/the hook of the moment around the fulcrum 7 of the bar 4 (], the separation l/ = 7 Dj of the roller 2
)-+', 1. 'Press force Pn of A and separation roller'! : Relationship C1, the distance between the fulcrum 7 of the lever 4 and the θ line of the pressure contact points of both rollers is X1, and the distance between the fulcrum 7 and the tangent line of the pressure contact points of both rollers is Y, then Y/X I can decide. However, since the separation and conveyance of this paper feeding device is due to the frictional force between rollers 1 and 2 and paper 3, rollers 1 and 2
2 wear out over time, and their outer diameters gradually decrease. In FIG. 1, if the outer diameters of both rollers 1 and 2 are decreased as shown by the two-dot chain line, the center position of the feed roller 1 will not change, but the separation roller 1 and the separation roller 2, which are always suppressed by the feed roller 1, will not change. At the center position, lever 4 is the fulcrum 7
By rotating counterclockwise around 1 and 7, it moves along an arc ``-'' centered on fulcrum 7, and as a result, the above X decreases to X', and conversely, Y changes to )'' As a result, the value of Y/X becomes larger.

In the past, there was a drawback that the paper return force TA for a constant pressing force PI3 of Zura 2 gradually decreased, the separation performance deteriorated, and reliability became poor.

1. This invention eliminates the two drawbacks of the conventional configuration of the friction pre-feeding device 1 in which a constant torque is applied to the separation roller in the paper return direction, and the pressing force of the separation roller is improved. One objective is to provide a highly reliable single-gear/friction-separation paper feeding device that hardly changes over time due to the relationship between the paper return force and the paper return force.

The present invention r-1 Kirani,
Yon ``J-Shini Torque for applying 41 constant torque,
Separate the cream from the press lever Φ
111, the problem of l-le cross caused by passing the gear to the torque reaching the i-varetion "J-ra" has been improved. It is also an object to provide a device i').

The present invention will be described and explained in detail based on the drawings showing the embodiments thereof. Figure 2 shows an embodiment in which the present invention is applied to a transfer paper feeding device of a 71L photocopier. FIG. 3 is a cross-sectional view of the feed roller 1, the roller 2 and the roller 1I.
FIG. 1 is a sectional view taken in a direction perpendicular to 1η11 showing IIll and members belonging to A1.

As shown in Figure 2, the paper 3 is placed on the bottom plate 11L of the bottom plate
The container is then loaded and raised to a predetermined height by a lifting device (not shown). A control device (not shown) applies pressure to the second side of the paper bundle using a predetermined timing in response to a paper feed signal, and rotates in the direction of the paper feed force. The paper is fed to a roller pair consisting of a feed roller 1 and a separation roller 2, which are provided on the downstream side. The feed roller 1 is rotated by a clutch (not shown) at a predetermined timing in a paper feeding direction indicated by an arrow in the figure. Sepa 1/-
A drive gear 13 (not shown) rotated by a drive source on the John roller 2, a gear 15 fixed to the separation roller 14, and a torque limiter 16 provided on the one shaft 14
7, a constant torque is applied in the paper return direction shown by the arrow in FIG. As will be described later, the separation roller 2 is pressed against the feed roller 1 with a predetermined pressing force by a -C pressure spring 5 via a pressure arm 4.

Separation roller 2 (=
The torque applied to J-q is as explained at the beginning (if there is no paper between the
If two or more sheets of paper get between the rollers, the frictional force between the first and second sheets of paper will be overcome and the separation line will be removed.
1-Ra 2 is set to a value that causes it to rotate in the return direction (Z).

Therefore, the paper is fed into feed r, ff-ra 1 and separator 1.
It is separated into one sheet by the roller 2 and sent between the guides 20, and then the roller 21 gives it a predetermined barrel horn, L-j, V-knee, etc. and corrects it to the photoreceptor drum. Paper is fed.

Soil Parayon Roller 2Fi, shown in Figure 3: J-
As shown in FIG.
It is inserted with a tightening force of 1ψ friction force required to do so. The right half of the torque limiter spring 18 is fully inserted into the separator spring 19 fixed to the separator spring 14 in a tightened state, thereby forming the torque limiter 16. The right end of the separation shaft 14 (Yo, this IIη11 and) 4 - the plane containing the troller shaft (i.e. the third
It is supported by a bearing 22 so as to be able to swing within a certain range (in the paper plane of the figure) and to be rotatable around the axis of the white meat. Separate lane shaft 1.4kJ: Tonoshi limiter 1
On the right side of 6, fix it to the machine frame as shown in Fig. 2, 71e, and then move the axis of feed roller 1 to the lane of roller 2 IIi.
It is pivotally supported by a slide bearing 24 that is slidably fitted into a guide 23 that guides the separation member 14 in a plane including ++. The lower surface of this bearing is pressed so as to be slidable by the upper surface of one end of the pressure arm, which is rotated about the fulcrum 7 by the pressure splinter 5. 2 is in pressure contact with the feed roller 1 with a constant pressing force D.

Since the separation roller section of this embodiment has the structure as described above, the relationship between the return force TA of the separation roller 2) and the pressing force Pl-3 of the separation roller is as follows.

As shown diagrammatically in FIG. 4, p, '1 Pressure force from the drive gear acting on the tooth surface of the separation shaft 15, P2, the inside of the mouth of the separation shaft 14 and the part attached to it, P, Apply the sliding force 24 to the pushing force by J- [A J-, 4, P (, - No 7 Pushing force between troller 1 and separation roller 2, 11 to the fulcrum 1: ll + receiver 22) From Pl, the distance L2 of the action boiling water is tr ■, )2 I, " 1゛1 L i tr ' J), //
Misalignment V, 1, from the hook engagement of the moment of the fulcrum 22, 1, l'+ +l-+ ['3-12"2+A4 P
4, the force P pushing the separation gear 15 is the ratio of the radius of the gear to the radius of the separation roller 2, for example 1.5, and the deviation is I゛蒐-J・5T8... (2 )]' , :
l+・°°゛”(3)(2H
: Substituting equation 3) into equation (1), we get 4-.

In other words, the relationship between I' and T'n is from the fulcrum 22 to the gear 15.
．． It is determined based on the distance between the 1111 receiver 24 and the separation roller 2. These positions do not change over time once -l is determined. As the separation roller wears, the ratio of the radii of the two separation rollers and the separation gear, for example, 1°5, changes slightly; however, in the structure of the present invention, when the separation roller 2 and the feed roller wear out, Since the bearing 24 of the separate lane "J-Ra" is inserted into the kite by the guide 23 while slipping on the upper surface of the pressure arm 4, the arrangement of "X" shown in FIG. 1 does not change.

In the past, ']' The relationship between A and PB can maintain the initial set value for a long period of time without being affected by the wear of the hammer.For example, the relationship between 'rA and Pl3 is as follows. It is appropriate to set 911< below.

P = O, 16TA + 400 [1) In Figure 5']
1. With A on the horizontal axis and P[) on the vertical axis. “A”+(curve shown for the above equation. In the figure, OP,
=400, and the slope of the straight line corresponds to 0.16.

Therefore, by making the support structure of the separation roller have the structure of the present invention, the slope of the straight line expressing the relationship TA]"13 and the height of the point TA-0 can be easily set to arbitrary values. I can do it.

In addition, as shown in this example, l.
A large torque can be set by providing the separation roller 2 and the integrated K seha v-, 7 Yon shaft 14.
The torque is transmitted to the separation roller 2, and the torque transmission loss is kept to a minimum.

Effects As described above, according to the present invention, it is possible to maintain the initially set value of the relationship between the pressing force of ``1-L'' and the paper returning force over a long period of time, so that stable paper feeding f1 can be achieved.
ability is obtained.

In addition, since the torque transmission loss due to the torque limiter is kept to a minimum, the problem of narrowing the setting range of the torque limiter is resolved.The increase in margin for torque changes in the I/L limiter over time provides a deflection effect. It will be done.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a conventional friction separation paper feeding device.
Fig. 2 is a sectional view showing an embodiment of the present invention, Fig. 3 is a sectional view taken along line III-III in Fig. 2, and Fig. 4 is a pressing force PB of the separation roller in the apparatus of the present invention.
A schematic diagram for explaining the relationship between the paper return force 'I'A and
FIG. 5 is an example of a curve diagram showing the relationship between TA and Pll obtained by the apparatus of the present invention. ■...Feed roller 2...Separation roller 3...Paper 4...Pressure arm 5...
...Pressure spring 14...Separation roller shaft 16...Torque limiter

Claims (2)

[Claims] (1) A friction separation paper feeding device having a feed roller that rotates in the paper feeding direction and a separation roller that pinches and presses against the paper path and applies a constant torque in the opposite direction to the paper feeding direction. One end of the separation roller shaft is rotatably supported in a plane including the axis of the shaft and the axis of the feed roller, and a separation roller is provided at the other end and pressed against the feed roller. 2. A paper feeding device characterized by comprising means for biasing the shaft in the direction of the feed roller and means for guiding the shaft so as to rotate within the 3r plane. (2) Scope 1 of the patented anti-icing system, characterized in that the axis of the separation roller described in 1 is integrally provided with a torque limiter that applies a constant torque to the separation roller.
Paper feeding device as described in section.