JPH02144347A - Sheet feeding device - Google Patents

Abstract

PURPOSE:To prevent the non-feed of a document by a method wherein the document is left in a looped state until, with resist rollers started to rotate, the document is held between the nip formed therebetween. CONSTITUTION:Lock claws 7C1 and 7C2 are formed on the circumferential surface of a cylinder member 7 to control drive of a feed roller 1, a handle roller 2, and gears G1, G2, and G3 of a cam 3, and first and second clutches are formed with the lock claws and a lock metal 9 engaged therewith. Since the second clutch is located, the cam 3 is stopped right before completion of one full turn, and a feed roller 4 holds the document in a looped state. Thereafter, simultaneously with the starting of the feed of the document by means of resist rollers 5 and 6, the second clutch is worked to rotate the cam 3, and a forward feed roller 4 is raised for holding. Since the document is nipped in a looped state between the resist rollers 5 and 6, the non-feed of sheets can be prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a paper feeding device for originals and other sheet-like paper used, for example, in electrophotographic copying machines, automatic document feeders, and the like.

[Conventional technology]

For example, as an electrophotographic copying apparatus, one shown in FIG. 5 is known. This Figure 5 shows an overall perspective view.
In the figure, 51 is a main body of the copying machine, and 52 is an automatic document feeder disposed above the main body 51 of the copying machine. In addition to a copy switch, a setting panel 53 is provided at a suitable location on the side of the main body 51 of the copying apparatus, and is capable of setting various modes such as duplex, enlargement, and continuous copying. Reference numeral 54 is a cassette in which transfer paper on which the original is transferred is set. On the other hand, on the side of the automatic document transport bag 5I52, there is provided a document placement table 55 on which a document is set, and on the document placement table 55 there is provided a document setting member 56 that can be slid laterally according to the size of the document. There is. Reference numeral 57 denotes an ejection tray from which the original on the original document holder 55 is conveyed inside by a paper feeder, which will be described later, and is ejected after being copied. In such an electrophotographic copying apparatus, as described above, when the continuous copy mode is started, the originals placed on the original placing table 55 are automatically fed into the interior one by one and subjected to the copying operation. Ru.

FIG. 6 is a schematic side sectional view for explaining the paper feeding operation.
FIG. 6(A) shows the positional relationship between gears, clutch members, and solenoids related to paper feeding, and FIG. 6(B) shows the original, each roller and cam related to paper feeding. In the figure, reference numeral 1 denotes a paper feed roller formed in a crescent shape by cutting off a part of its circumference, and it rotates once from the position shown in figure (B) and ends its rotation at the position shown in the figure. Reference numeral 2 denotes a sorting roller that forms a pair with the paper feed roller 1, and 3 a cam that rotates once from the position shown in the figure in synchronization with the paper feed roller 1 and completes its rotation at the position shown in the figure.

The cam 4 rotates in synchronization with the paper feed roller 1, and when the cam 3 rotates clockwise and comes off the arm 4a, it descends onto the placed document and advances the topmost document, and the cam completes one rotation. Then, when it slides onto the arm again, it is a forward feed roller that rises above the document as shown. Reference numerals 5 and 6 indicate registration rollers that further feed the document fed from the paper feed roller 1 inward.

In Figure (A), GI G2 and G3 are gears of the paper feeding roller 1, sorting roller 2, and cam 3, respectively. Note that gears G4 and G5 are idle gears.

8 is a solenoid, and the locking fitting 9 is normally held by a spring 10.
It is locked to a locking pawl 11C on the circumferential surface of the clutch member 11 connected to the rotating shaft of the paper feed roller 1. When the solenoid 8 operates, the locking metal fitting 9 comes off from the locking claw 11c against the spring.
Rotate the paper feed roller 1. This solenoid 8 is designed to operate only when paper feeding starts.

In the above configuration, when the forward feed roller 4 and the paper feed roller 1 rotate and feed the document to the registration roller 5.6 position, the forward feed roller 4 and the paper feed roller 1 are in the state shown in FIG. Stop rotation.

The diameter of the paper feed roller 1 is set so that the document is sufficiently fed to the registration roller 5.6 position to form a loop. Immediately after this, the registration rollers 5.6 rotate to further transport the document inward. In this way,
Originals P on the original platen 55 are sequentially fed into an automatic document feeder for copying processing.

[Problem to be solved by the invention]

As mentioned above, even if the original reaches the registration roller 5.6 position, it will be fed for a short time by the paper feed roller 1 etc., so the original will bend slightly due to the flexibility of the original paper ( (hereinafter referred to as a loop). However,
After the paper feed roller 1 (and cam 3) completes one rotation, the sixth
When the forward feed roller 4 rises as shown in Figure (B), the document is released from the forward feed roller 4, so the bending force acts backwards, causing the document to return to the registration roller 5.
6, and as a result, even if the registration rollers 5.6 start rotating immediately thereafter, a problem arises in that the document is not fed into the automatic document feeder.

An object of the present invention is to prevent a document from not being fed by forming the loop until the registration roller starts rotating and clamps the document.

[Means to solve the problem]

In the present invention, a cam to which rotational force is transmitted from a drive source through a first clutch rotates once for each paper feeding operation, and in synchronization with the one rotation, the cam is lowered from above the paper tray onto the paper. A paper feeding device configured to feed the paper to a pair of downstream registration rollers by a forward feed roller that is raised at the end of one rotation, and then the pair of registration rollers rotate to further feed the paper to the downstream side. A second clutch is provided which stops the rotation of the cam just before the cam makes one rotation and starts rotation in synchronization with the rotation of the pair of registration rollers, and the second clutch stops the rotation of the cam just before the cam makes one rotation, and the second clutch stops the rotation of the cam just before the cam makes one rotation, and starts rotation in synchronization with the rotation of the pair of registration rollers. This is characterized in that the forward feed roller is in a state immediately before starting to rise.

Further, the first clutch is constituted by a spring clutch having one locking claw at a proper position on the circumferential surface of the cylindrical member, and the second clutch is configured to lock one of the locking claws on the circumferential surface of the cylindrical member A locking pawl may be formed at a proper position on the circumferential surface different from the pawl.

[Effect]

According to the present invention, the rotation of the cam is stopped by the second clutch just before the cam completes one revolution, and the advance roller remains lowered onto the paper, forming a loop. Immediately after this, when the registration rollers rotate, the paper is held between the registration rollers and feeding begins, and the second clutch operates in synchronization with the registration rollers, and the cam starts rotating, causing the paper to advance. Raise the roller to release the loop.

Further, when a spring clutch is used as the first clutch, the components other than the locking pawl of the second clutch are common.

〔Example〕

Hereinafter, a case will be described in which the present invention is applied to a paper feeding device of an automatic document bundle feeding device in an electrophotographic copying apparatus shown in FIG. 5.

FIG. 1, FIG. 2, and FIG. 4 are a schematic side sectional view and a schematic plan sectional view for explaining the operation and configuration of the paper feeding device according to the present invention.

Figure 1 shows the document forming a loop, and the second
The figure shows the state in which the original is fed by the registration rollers 5.6 after the state shown in FIG.

The configuration will be described below with reference to the above drawings.

Reference numeral 1 denotes paper feed rollers made of a material with a large friction coefficient such as rubber, which has a circular cross-section and a part of its periphery cut out to form, for example, a crescent shape.As shown in FIG. They are arranged on the same axis 1a with an interval of . In addition,
The shape of this cut surface may be planar. Reference numeral 2 denotes a sorting roller (not shown in FIG. 4) made of a material with a relatively small coefficient of friction, which is paired with the paper feed roller 1 and rotates in synchronization with the paper feed roller 1 in its axial direction. They are arranged alternately or in opposite positions.

Note that when the sorting rollers 2 and the paper feeding rollers 1 are arranged alternately, their rotating surfaces may partially overlap to facilitate the sorting effect.

A cam 3 is rotationally driven in synchronization with the paper feed roller 1 through gears G I G 5 and G3, and is used to move the forward feed roller 4 up and down on the document table 55 through an arm 4a. be. The forward feed roller 4 is configured to rotate only while the paper feed roller 1 is rotationally driven via a connecting belt 4b shown in FIG. Reference numerals 5 and 6 designate registration rollers having a paired structure for further feeding the document fed through the paper feed roller 1 into the interior.

GIG2 (not shown in FIG. 4) and G3 are gears for the paper feed roller 1, the paper handling ports 2 and 3, respectively. The gears G4 and G5 are idle gears for rotating the sorting roller 2 and the cam 30 in opposite directions to the paper feeding roller 1. Reference numeral 7 denotes a cylindrical member (see FIG. 4) that is a member of a spring clutch, which is an example of a clutch that transmits rotational force from a drive source (not shown) to the shaft 1a of the paper feed roller 1. As shown in FIGS. 1 and 2, the cylindrical member 7 has locking claws 7cl and 7c2 called clutch collars formed at appropriate positions on its circumferential surface. Further, a coil spring 71 is fitted into the cylinder of the cylindrical member 7 at least on one end side so as to restrict rotation relative to the cylindrical member 7, and a gear shaft 72 from a drive source is connected from both sides of the coil spring 71. A boss 73 for coupling with the rotating shaft 1a of the paper feed roller 1 is fitted into the coil spring in a screwed state, and under normal conditions, the rotation of the drive source 72 is transmitted to the paper feed roller 1 via the coil spring 71.
On the other hand, a locking metal fitting 9, which will be described later, locks the locking claws 7cl, 7G2 to rotate the cylindrical member 7,
That is, when the rotation of the coil spring 71 is stopped, the diameter of the coil spring 71 acts in the direction of opening due to the rotation of the shaft 72 of the drive source, so that the rotation shaft 1a of the paper feed roller 1 is rotated again.
Rotational force is not transmitted to. Reference numeral 8 denotes a solenoid consisting of a spring 1o and the locking metal fitting 9. Normally, the locking metal fitting 9 is brought into contact with the circumferential surface of the cylindrical member 7 by the spring 10, and the paper feed slot-latch is closed at the positions of the locking claws 7cl and 7e2. The rotation of 1 is stopped. On the other hand, when the solenoid 8 is activated, the locking metal fitting 9 is separated from the locking claws 7cL to 7c2, and the paper feed roller 1 is rotated until the next locking claw 7c2, 7cl comes around. In this way, a clutch is constructed from the cylindrical member 7 side and the solenoid 8 side.

The locking claws 7cl and 7c2 are formed at the following positions on the circumferential surface of the cylindrical member 7. That is, the locking claw 7el is similar to the conventional clutch, so that the cut surface of the paper feed roller 1 is connected to the separating roller 2.
This is the position where the solenoid 8 is locked by the locking fitting 9 when it is in the position facing the solenoid 8 (see FIG. 2). In addition, the locking claw 7
c2 is the force, and is the position just before the cam 3 completes one rotation, that is, the position where the cam 3 has rotated to the position just before it contacts the arm 4a and slides to raise the forward feed roller 4 (see Fig. 1). , thereby forming a so-called second clutch.

Note that the paper feed roller 1 sufficiently feeds the document to the registration rollers 5.6 before making one rotation (between the locking claws 7el and 7c2), so the paper feed roller 1 is designed to feed the document sufficiently to the registration rollers 5.6, compared to conventional paper feed rollers. A somewhat larger diameter is required.

Next, the operation of the above configuration will be explained.

FIG. 3 is a timing chart illustrating the paper feeding operation.

First, when the copy switch is turned on just before time tQ (signal a), the drive source starts rotating (signal b).

Immediately after that (time 10), the solenoid 8 operates to operate the clutch (signal C1) and release the locking of the locking pawl 7cl. Then, the paper feed roller 1 and the cam 3 start rotating (signal D1), and the advance roller 4 immediately descends onto the document (signal e). As a result, the uppermost original on the original placing table 55 is forward-fed, passes between the paper feed roller 1 and the sorting roller 2, and is fed to a position between the registration rollers 5.6 (immediately before time t1). In order to ensure feeding, this feeding operation is carried out until time t1 when the rotating locking claw 7c2 is locked with the locking fitting 9. At this point, the paper feeding roller 1, the separating roller 2. Cam 3 and advance roller 4
stops rotating. This state is shown in FIG.
is regulated between the registration roller 5.6 and the advance roller 4, and a loop is formed. Therefore, the document is maintained in contact with the position where it is sandwiched between the registration rollers 5 and 6.

Immediately thereafter, at time t2, when the registration rollers 5.6 start rotating, for example, by another drive source (signal f
), the solenoid 8 is activated at the same time or with a delay of a minute time (signal C2), and the locking fitting 9 is disengaged from the locking claw 7e2, and the paper feed roller 1, which has been stopped for a period of time t1 to t2,
The sorting roller 2% cam 3 and the advance roller 4 start rotating again (signal D2, El). Then, the paper feed roller 1 completes its rotation until the locking claw 7cl is locked with the locking metal fitting 9, that is, after completing one rotation (time 1+). At this time, the cam 3 also rotates, and as a result, the advance roller 4 rises from above the document, the loop maintained between t1 and t2 is released, and one revolution of the cam 3 is also completed. That is,
At this point, the paper feed roller 1, cam 3, and advance roller 4 are
returns to the state before the copy switch was turned on.

On the other hand, the registration rollers 5.6 rotate to sandwich the looped original and feed it further downstream for a predetermined period of time to be subjected to copying processing.

Note that by allowing the loop to be released for a short time as described above, feeding in the state where it is held by the registration rollers 5.6 can be made more reliable.

Further, the clutch is not limited to the structure as in this embodiment, and may be, for example, an electromagnetic clutch for boat fishing, that is, a structure in which rotational driving force is transmitted while a control signal is output. You can.

Furthermore, in this embodiment, most of the structure of the second clutch having the locking pawl 7c2 is included in the clutch having the locking pawl 7el, but it is also possible to configure both separately.

Further, in this embodiment, the drive source is connected to the paper feed roller 1, but it may be connected to the cam 3.

〔Effect of the invention〕

As explained above, according to the present invention, the document is in a state where it forms a loop at least by the forward feed roller until the registration roller starts rotating, so that the document is not caught by the registration roller. It will be done reliably,
Feeding becomes accurate.

Further, by using a spring clutch, most of the members constituting the first and second clutches are common, and the configuration can be simplified.

shaft, 73...Boss for connection

Claims (1)

[Claims] 1. The cam, to which rotational force is transmitted from the drive source via the first clutch, rotates once for each paper feeding operation, and in synchronization with this one rotation, the cam moves from the paper placed on the paper to the paper. The paper is fed to a pair of downstream registration rollers by a forward feed roller that is lowered and raised at the end of one rotation, and then the pair of registration rollers rotates to feed the paper further downstream. The paper feeding device includes a second clutch that stops the rotation of the cam just before the cam makes one revolution and starts rotation in synchronization with the rotation of the pair of registration rollers, and A paper feeding device characterized in that the forward feed roller is in a state immediately before starting to rise at the stop position. 2. The first clutch is constituted by a spring clutch having one locking pawl at a proper position on the circumferential surface of the cylindrical member, and the second clutch is constituted by a spring clutch having one locking pawl at a proper position on the circumferential surface of the cylindrical member.
2. A paper feeding device according to claim 1, further comprising a locking pawl formed at a proper position on the circumferential surface different from the locking pawl.