JPS5851258B2 - Sheet conveyance device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sheet conveying device, and specifically to a sheet conveying device comprising a checker 7 and a sheet gripper fixed thereto.

A transfer-type electronic copying machine is an example of a device that uses the sheet conveying device.

First, an example of an electronic copying machine to which the present invention is applied will be explained with reference to FIG. 1. In the figure, reference numeral 1 indicates a photosensitive drum that rotates in the direction of the arrow.

Around the photoconductor drum 1, there is a charging device 2 that charges the photoconductor, and a document (not shown) placed on a document table 3.
an exposure optical system 4 that transmits the image to the photoreceptor surface; a developing device 5 that visualizes the electrostatic latent image formed by the optical system;
At the transfer position A, a transfer sheet is brought into contact with this visible image, and the sheet is transferred, fixed by a fixing device 6, and then discharged by a sheet conveying device T1. A transfer charger 8 and a static eliminator 9 each transfer the visible image. It is located.

As shown in FIG.
1 and 11, 12 and 12, and a sheet gripper 13 which is arranged at right angles lζ to the chino and whose both ends are fixed to the chino.

The detailed configuration of the sheet gripper 13 will be described later.

Further, in the figure, a paper feeding device 16 consisting of a sheet cassette 14 and a paper feeding roller 15 is disposed on the right side.
A pair of paper ejection rollers 17 is arranged on the left side.

Now, when a print button (not shown) is pressed, the photoreceptor drum 1 begins to rotate in the direction of the arrow, and the surface of the photoreceptor is sequentially charged by the charging device 2.

When the leading edge of the image forming area of the photoconductor corresponds to the exposure optical system 4, the document mounting table 3 starts moving in the direction of the arrow, and the image of the document placed thereon is exposed by the optical system 4. The body is irradiated.

The electrostatic latent image thus formed is developed with toner supplied by the developing device 5 to become a toner image.

On the other hand, at the same time or after a certain period of time when the print button is pressed, the paper feed roller 15 rotates once and the sheet cassette 14
The upper sheet S is sent out toward the sheet gripper 13.

The sheet holding claw of the sheet gripper 13 is open in the standby position shown in FIG. 1, and the sheet S is fed into this.

When the leading edge of the area of the photosensitive drum 1 on which the toner image is formed rotates to the transfer position A, the sheet conveying device 7 has started rotating and the sheet gripped by the sheet gripper 13 is S is brought into contact with the surface of the photoreceptor to transfer the toner image.

At this time, the transfer charger 8 acts.

After the toner image has been transferred, the photoreceptor drum 1 is transferred to a static eliminator 8.
The residual potential is removed by

Further, when the sheet conveying device 7 passes through the fixing device 6, the sheet conveying device 7 fixes the toner image on the sheet.

The sheet that has been fixed is removed from the sheet gripper 13 at the paper discharge position B, and is discharged outside the machine by a pair of paper discharge rollers 17.

After sending out the sheet, the sheet conveying device 7
After further rotation, the sheet gripper returns to the standby position shown in FIG. 1 and is stopped.

As described above, the sheet conveyance device 7 must grip and convey the leading edge of the sheet at the standby position and release it at the sheet discharge position B.

The present invention provides a sheet conveying device in which a sheet holding claw of a gripper that grips a sheet is devised and the gripper is moved on the pitch of a Cheno, thereby making it possible to discharge the sheet extremely easily. The purpose is to

The present invention will be explained below with reference to illustrated embodiments.

First, referring to FIG. 3, to explain the configuration of the sheet gripper 30 used in the apparatus of the present invention, one of the links constituting a pair of chains 31 is formed as an attachment link 32 having a mounting hole 32a. , their attachments 32b face each other.

The attachment 32b includes both ends 3 of the support body 33.
3a are fixed with screws 34, respectively.

The rear end edge of the support body 33 is bent upward and then further rearward to form a flat sheet gripping portion 35 .

Note that since the sheet gripper 30 is moved in the direction of arrow a, it will be referred to as a front end side and a rear end side in this moving direction.

A shaft support 36 is fixed to the lower surface of the support 33, and a bearing portion 36a that rotatably supports a sheet presser claw support shaft 37 is formed on the tip side thereof.

The support shaft 37 has a sheet holding claw 38 as shown in FIG.
is fixed at its base end 38a with a screw (not shown).

The sheet holding claw 38 is made of an elastic member, and its free end 38b faces the sheet gripping portion 35 of the support body 33.

Further, a stopper 39 is formed at the center of the free end of the sheet presser pawl 38 by punching it out and bending it downward.

The free end 38b of the sheet presser claw 38 and the stopper 3
As shown in FIG. 5, the sheet locking portion 40 formed by the gripper 9 is open toward the rear side of the gripper 30, and its angle θ is an acute angle.

Note that the sheet presser pawl is not limited to the shape shown in FIG. 4, but may have a free end 38bA that presses the sheet and a stopper 39A, as shown in FIGS. 6 and 7.

Further, if the stopper 38Aa is folded back to form a sheet locking portion like the sheet holding claw 38A shown in FIG. 8, it becomes easier to separate the sheet when releasing the sheet, which will be described later.

In the sheet holding claws shown in FIGS. 6 to 8 above, it goes without saying that the sheet locking portions formed by the claws and the stopper are all formed at acute angles.

Cam followers 41 are provided at both ends 37a of the support shaft 37.
and a leaf spring 42 are fixed at their respective bases with screws 43.

The free end 42a of the leaf spring 42 is held at the lower part of the extending end 35a of the sheet gripping portion 35 of the support body 33, and is held against the support shaft 37 by a sheet presser claw 38 fixed thereto. The free end 38b of the sheet gripping portion 35 has a tendency to be pressed against the sheet gripping portion 35.

Note that the rotational behavior of the support shaft 37 is independent of the leaf spring.
It may also be provided by a helical spring (not shown).

The free end 41a of the cam follower 41 is 1. It is located toward the tip side of the support shaft 37, and further protrudes from the upper edge of the chino 31 in the height direction (see FIG. 10).

Next, the driving mechanism of the chain 31 that holds both ends of the sheet gripper 30 and moves it will be explained with reference to FIG. It's wrapped around.

This sprocket wheel 44 has six pitches, which is the number of pitches of the chino 31.
It has 1/1 the number of teeth.

Therefore, when the sprocket wheel 44 rotates six times, the chino 31 rotates once.

The sprocket transport 44 is fixed to the chino drive shaft 46.

As shown in FIG. 15, this drive shaft 46 is rotatably supported by immovable side plates 48 and 49.

A sheet feed roller 47 having a notch 47a (see FIG. 11) into which the sheet gripper 30 fits is fixedly attached to the ceno drive shaft 46.

A sprocket wheel 50 is attached to one end of the chino drive shaft 46.
It is attached via a one-turn clutch 51.

This one-turn clutch 51 is formed with four parts 51a.

The sprocket wheel 50 includes a sprocket wheel 53 of the driving shaft 52, an idle sprocket wheel 54, and a sprocket wheel 56 fixed to a shaft 55 that rotates the photosensitive drum 1 and the paper feed mechanism. Che 757 is hung.

A small diameter gear 58 is fixed to the bent end of the chino 1 drive shaft 46.

A large diameter gear 59 having six times as many teeth as the small diameter gear 58 meshes with the small diameter gear 58 .

Therefore, the large diameter gear 59 rotates once when the small diameter gear 58 rotates six times.

The large-diameter gear 59 is fixed to one end of a camshaft 60 rotatably supported by the side plates 48 and 49.

The cam 6 has a recess 61a formed at the curved end of the cam shaft 60.
1 is fixed.

Therefore, when the sprocket transport 44 and the small diameter gear 58 that is substantially integral therewith rotate six times, the chain wheel 31, the large diameter gear 59, and the cam 61 that is substantially integral therewith rotate one revolution.

A shaft 62 is disposed above the chino drive shaft 46 and has both ends loosely fitted into elongated vertical holes bored in the side plates 48 and 49.

An idle roller 63 corresponding to the above-mentioned conveying roller 47 is attached to this shaft 62, and the roller 63 is in contact with the roller 47 due to its own weight.

Further, a support shaft 64 is fixedly planted on the side plate 49, and a two-arm member 65 is swingably attached to this shaft 46.

The two-arm member 65 has a tendency to abut against the cam 61 about the support shaft 64 by a tension spring 67 placed between a pin 66 fixed thereto and a stationary member (not shown). It is given.

The tip of one arm 65a of the two-arm member 65 is bent, and the recess 51a (first
5) is formed with a locking portion 68 that engages and disengages.

Further, a cam follower 69 that comes into contact with the periphery of the cam 61 is fixedly provided approximately in the middle of the arm 65a.

On the other hand, a disk 71 on which a pin 70 is fixed is fixedly attached to the shaft 1a of the photoreceptor drum 1.

One end 73a of the actuating arm 73 is located within the rotation locus of the pin 70.

The operating arm 73 is swingably supported by the side plate 49 by a support shaft 74.

Further, the bent end 73b is connected to the upper arm member 65 by the connecting rod 75.
It is connected to the pond arm 65b.

Therefore, the operating arm 73 is connected to the spring 6 via the connecting rod 75.
This means that the rocking behavior is given by 7.

As shown in FIG. 13, the sheet gripper 30 is disposed perpendicular to the chino 31 of the drive mechanism configured as described above in a plan view.

Further, the seat gripper 30 is attached to the chino 31 so that the seat locking portion 40 (see FIG. 5) is positioned and moved on the pitch circle P of the chino 31 (see FIG. 11).

Next, the mechanism for releasing the sheet from the sheet gripper disposed at the sheet ejection position will be explained. In the rotation locus O (see FIG. 13) of the cam follower 41 of the sheet gripper 30, the side plate 4B, Cam 76.7 fixed to 49
7 (only one is shown in FIG. 13).

The cams 76 and 77 have a rotating sheet gripper 3.
The cam followers 41 and 41 of No. 0 come into contact with each other and swing the sheet presser pawl 38 against its tendency to open the pawl.

The relative positions of this cam and the cam follower are determined so that the seat locking portion 40 swings outward from the pitch circle P of the chino 31 when the claw is opened (see FIG. 14).

Further, as shown in FIG. 13, a comb-shaped sheet guide pawl 78 is disposed on the side of the rotation locus of the sheet presser pawl.

The tip 7 of this sheet guide claw 78? As shown in FIG. 14, point a is located between the pitch circle P of the chino 13 and the rotation locus of the seat locking portion 40 that is swung outward from this pitch circle.

In FIG. 10, reference numeral 79 indicates a roller that is rotated in the direction of the arrow by a drive mechanism (not shown), and together with a roller 80 that rotates as a result of this roller, a pair of paper ejection rollers 81 is constituted.

Further, as shown in FIG. 9, the sheet gripper 30 at the starting position of the sheet conveying device has a cam follower 41 in contact with a cam 82 fixed to a stationary member (not shown) to open its claws. .

As described above, the sheet conveying device of the present invention can be broadly classified into:
It consists of a sheet gripper that grips the sheet, a driving mechanism using a chino that moves the gripper, a claw opening/closing mechanism of the sheet gripper, and a sheet guiding claw.

Below, the operation of the device of the present invention will be explained.

When a print button (not shown) is pressed, the photosensitive drum 1
begins to rotate in the direction of the arrow (see Figure 12).

At this time, the Cheno 31 moves the sheet gripper 30 to the ninth position.
It is located in the standby position shown in the figure, and is in a so-called starting position 1 in which the locking portion 68 of the two-arm member 65 is engaged with the one-rotation clutch 51 and rotation transmission from the drive source is cut off.

When the print button is pressed or after a certain period of time, the paper feeding device (not shown) is activated, and as shown in FIG.
The sheet S is fed into the

The fed sheet S waits with its leading edge Sa in contact with the sheet locking portion 40 (see FIG. 5).

When the pin 71 of the disc 12 that rotates integrally with the rotating photosensitive drum 1 engages with one end 73a of the actuating arm 73 and swings it in the direction of the arrow, The two-arm member 65 connected by the rod 75 swings to release the locking portion 68 from the one-turn clutch 51.

The released one-turn clutch 51 transmits the rotation of the sprocket 50 to the chino drive shaft 46.

As the chino drive shaft 46 rotates, the sprocket 44 rotates the chino 31 in the direction of arrow C.

At this time, the cam follower 41, which had opened the sheet holding pawl 38, came off the cam 82, and the sheet toggle ripper 30, which had been feeding the sheet S in the standby position, released the water 38.
Close.

The sheet holding claw 38 conveys the sheet S by pinching the leading edge Sa of the sheet S with the sheet gripping section 35 .

Since the sheet locking portion 40 moves on the pitch circle of the chino 31, the leading end Sa of the sheet S to be conveyed also moves on the pitch circle.

When the sheet gripper 30 is rotated to the sheet discharge position, the sheet gripper 30 fits into the notch 47a of the sheet feed roller 47o, as shown in FIG.

Then, as shown in FIG. 14, when the free end 41a of the cam follower 41 comes into contact with the cam surface 76a of the cam 16, the cam follower 41 rotates the support shaft 37 against its habit, and the sheet presser claw 38 oscillate.

Due to the swinging of the sheet holding pawl 38, the sheet locking portion 4
0 is swung outward from the pitch circle P of the chino 31.

The leading edge Sa of the sheet that is moved while remaining outside the pitch circle is attached to the leading edge 78a of the sheet guide claw 78 located between the pitch circle P and the sheet locking portion 40 in the swing position. It is guided and released from the sheet gripper 30 as indicated by SA.

When the leading edge Sa of the sheet is released from the sheet gripper, the sheet S is held between the sheet feed roller 47 and the idle roller 63, and receives the feeding action of these rollers.

Note that the chino 31 that moves the seat gripper 30 stops at the starting position when the sprocket wheel 44 rotates six times.

That is, the two-arm member 65 swings, and the one-turn clutch 5
1 is released, the small diameter gear 58 rotates the cam 61 in the direction indicated by the arrow (see FIG. 12) via the large diameter gear 59.

As the cam 61 rotates, the circumferential surface of the cam 61 pushes out the cam follower 69 of the two-arm member 65 from the concave portion 61a, and holds the locking portion 68 in a position where it does not engage with the concave portion 51a of the one-turn clutch 51 (see FIG. 15). do.

Then, when the one-turn clutch 51 rotates six times, the cam 6
1 rotates once, the cam follower 69 falls into the recess 61a, and the locking portion 68 engages with the recess of the one-turn clutch to stop the rotation.

As a result, rotation transmission to the chain 731 is cut off, and the chain 731 stops.

This position is the starting position of Che 731.

The sheet holding claw 38 of the sheet gripper in the sheet conveying device of the present invention is formed with a stopper 39 that forms an acute angle with the stopper 39. By forming the stopper 39 in this way, the following effects can be obtained. .

If the sheet locking part 400 is made at an obtuse angle as shown in FIG. Because they are in close contact, it is not possible to release the sheet reliably.

However, if the sheet locking portion is formed at an acute angle, as shown in FIG. 17, when releasing the gripped sheet S as shown by the chain line, when the sheet presser pawl 38 swings in the direction of the arrow, the stopper 39 will move. By lifting the leading end Sa of the sheet, the sheet can be reliably released.

Further, by moving the sheet locking portion on the pitch circle of the checker 7, it is possible to easily synchronize the sheet conveyance device and the locking mechanism.

Further, by swinging the sheet locking portion to the outside of the pitch circle and providing sheet guide claws, it is possible to more reliably separate the sheet from the sheet gripper.

In the illustrated embodiment, there are two cams (designated by reference numerals 76 and 7 in FIGS. 12 and 15) for opening and closing the sheet presser pawl.
7), but it may also be provided on either side.

[Brief explanation of drawings]

FIG. 1 is a schematic side view showing an example of an electronic copying machine to which the sheet conveying device of the present invention is applied, FIG. 2 is a schematic perspective view showing only the same sheet conveying device, and FIG. 3 is a sheet conveying device of the present invention. 4th perspective view showing a sheet gripper used in
The figure is a perspective view showing only the same sheet presser pawl, FIG. 5 is a side view of the same, FIGS. 6 to 8 are perspective views showing different examples of the sheet presser pawl, and FIG. 9 is a standby of the sheet gripper. 10 is a side view showing the paper discharge position of the sheet conveying device of the present invention, FIG. 11 is a side view showing only the essential parts, and FIG. 12 is a perspective view of the device of the present invention. Fig. 13 is a plan view partially showing the paper ejection position, Fig. 14 is an enlarged side view showing the action of the sheet gripper during paper ejection, and Fig. 15 is a plan view partially showing the sheet ejection position.
The figure is a front view showing only the essential parts of the present invention, Figure 16 is a side view showing a sheet gripper with a sheet locking part formed at an obtuse angle, and Figure 17 is a device of the present invention with a sheet locking part formed at an acute angle. FIG. 31...Cheer 7.38...Sheet presser claw, 39...Stopper, 40...Sheet locking part, P...Cheer 7 pitch circle, S...
...Seat, 78...Seat guide claw.

Claims (1)

[Scope of Claims] 1. A pair of rotating chenos, a support member having both ends fixed to the chenos, disposed at right angles to the chenos, and having a sheet gripping portion formed on its rear edge; a sheet presser claw support shaft rotatably attached to the leading edge of the support; and a plurality of sheets whose base ends are fixed to the support shaft and whose free ends face the sheet gripping portion of the support. a presser pawl; a means for imparting a rotational habit to the support shaft in a direction of pressing the free end of the sheet presser pawl against the sheet gripping portion; In a sheet advance device consisting of a cam follower that rotates against
Sheet transport device 2, characterized in that the sheet presser pawl is provided with a stopper that regulates the leading edge of the sheet and forms an acute angle with the sheet presser pawl toward the rear. 2. The sheet conveying device according to claim 1, wherein the sheet locking portion moves on a pitch circle of the chino. 3. The sheet conveying device according to claim 1 or 2, characterized in that the sheet locking portion is swung outside the pitch circle of the chino at the sheet discharge position. 4. At the paper ejection position, the sheet is placed on the side of the rotation locus of the sheet presser pawl and between the pitch circle of the chino and the sheet locking part that is swung outward from this pitch circle. A sheet conveying device according to claim 1, 2, or 3, characterized in that a guide claw is provided.