JPH04194885A - Clip device for transfer device - Google Patents

Abstract

PURPOSE:To prevent sudden release of a load at the time of closing action of a clipper by restricting opening/closing action of the clipper by a restricting means. CONSTITUTION:When turning cams 41, 42 pass through a top part of a fixed side cam 48 by rotating a transfer drum 21, the cams 41, 42 are gradually turned, by energizing force of a tension spring 45 and along a shape of cam surfaces 48a, 48b of the cam 48, in the reverse direction to the above-mentioned and returned to the original attitude. Simultaneously, also a solenoid 52 is turned off, and an attitude control cam 49 is turned in the reverse direction to the above-mentioned by a spring 50 to place the fixed side cam 48 in a refuge attitude. Especially also in the case of closing a clipper 40, protruding parts 41b, 42b of the cams 41, 42 are brought into contact with the fixed side cams 48, 53 to restrict movement of the cams, so that a trouble of color displacement or the like can be prevented by improving transfer performance without suddenly changing a load in a drive system of the drum 21.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a clip device for holding a recording sheet on the outer peripheral surface of a transfer device and for separating the recording sheet from the transfer device.

[Conventional technology]

Generally, in a full-color copying machine, a transfer drum is provided opposite a photoreceptor drum. A recording paper is wrapped around the outer peripheral surface of the transfer drum, so that the image formed on the photosensitive drum is transferred to the recording paper on the transfer drum.

The transfer drum is provided with a clip device in order to wrap the recording paper around the transfer drum or to separate the recording paper from the transfer drum.

FIG. 6 shows a conventional clip device provided on a transfer drum. This clip device includes a lifting member 71 whose tip end is inserted into the lower surface of the recording paper 70, and a clipper 72 that grips the recording paper 70 together with the lifting member 71. On the base side of the lifting member 71 and the clipper 72, a rotation shaft 73 is arranged parallel to the axis of the transfer drum. A bottle (not shown) is fixed to the rotating shaft 73 at a predetermined angle in a direction intersecting the rotating shaft 73, and this bottle abuts each of the lifting member 71 and the clipper 72 from below. , each member 71, 72 is adapted to open upward. The end portion 73a of the rotation shaft 73 is configured to be rotated within a predetermined angular range by a cam 74 provided on the fixed side inside the transfer drum. Further, a torsion spring 75 is attached to the upper part of the lifting member 71 and the clipper 72.
are respectively arranged, and the lifting member 71 and the clipper 72 are each urged downward by the torsion springs 75. A separating claw 76 is fixed to the main body frame of the copying machine in the vicinity of the transfer drum.

In such a conventional crimping device, when the transfer drum rotates to the recording paper feeding position, the rotation shaft 73 comes into contact with the outer peripheral surface of the cam 74 and is rotated. This results in
The clipper 72 rotates in a direction away from the outer peripheral surface of the transfer drum and assumes an open position.

Then, the recording paper 70 is sandwiched between the stay of the transfer I° ram (not shown) and the clipper 72, and the leading end of the recording paper 70 is gripped.

When the transfer operation is completed and the recording paper 70 is to be sent to the subsequent conveyance system, the rotation shaft 73 rotates in the same manner as described above, and the lifting member 7
1 and clipper 72 are lifted. This results in
The leading edge of the recording paper 70 is far away from the outer peripheral surface of the transfer drum and rides on the separating claw 76 . By further rotating the transfer drum in this state, the recording paper 70 is separated from the transfer tram and sent along the separation claw 76 to the subsequent conveyance system.

[Problem to be solved by the invention]

In the conventional clipping device, when lifting the clipper 72 or the like, the rotating shaft 73 rides on the outer peripheral surface of the cam 74 against the biasing force of the torsion spring 75. Therefore, the biasing force of the torsion spring 75 acts as a load on the transfer drum drive system.

However, when the clipper 72 and the like close, the cam and the rotating shaft 73 come out of contact, and the load on the drive system is suddenly released. In this way, when the clipper 72 and the like are closed, the load is suddenly released, resulting in large load fluctuations on the drive system, which ultimately has an adverse effect on image formation.

SUMMARY OF THE INVENTION An object of the present invention is to provide a crimping device for a transfer device that can eliminate sudden changes in load on a drive system during opening and closing operations of a clipper.

[Means to solve the problem]

A clip device of a transfer device according to the present invention is a device for holding a recording sheet on the outer peripheral surface of the transfer device and separating the recording sheet from the transfer device. The clipper includes a clipper, a clipper opening/closing means, and a regulating means.

The clipper is provided on the outer periphery of the transfer device so as to be openable and closable, and grips the leading end of the recording sheet. The clipper opening and closing means is provided in the transfer device and is a means for opening and closing the clipper. The regulating means is a means for regulating the opening and closing operations of the clipper by the clipper opening/closing means.

[Effect]

In the present invention, the leading end of the recording sheet is gripped and lifted by a clipper provided on the outer periphery of the transfer device. This clipper is opened and closed by a clipper opening/closing means, whereby the recording sheet is held on the transfer device or separated from the transfer device. The opening and closing operations of the clipper are each regulated by a regulating means.

Therefore, it is possible to prevent the load from being abruptly released during the closing operation of the clipper unlike in the conventional device, and the opening and closing operations are performed smoothly, and load fluctuations on the drive system are reduced.

〔Example〕

FIG. 1 is a schematic cross-sectional view of a full-color copying machine employing an embodiment of the present invention.

In the figure, a document table 2 on which a document is placed is arranged at the top of a copying machine main body 1, and a document presser 3 is provided on the top surface of the document table 2 so as to be openable and closable. Further, on the left side of the copying machine main body 1, a paper discharge tray 4 and a plurality of paper feed power centers 5 are arranged. Furthermore, a tray 6 for bypass paper feeding is arranged on the right side.

A photosensitive drum 7 is arranged inside the copying machine main body 1 . Around the photoreceptor drum 7, in addition to a charging device, a transfer device, a paper separation device, and a cleaning device, developing devices 10, 11, 12, and 13 are arranged vertically side by side.
A developing device 8 is provided. The arrangement of the developing units is as follows: from above, magenta developing unit 10, cyan developing unit 11
, a yellow developing device 12, and a black developing device 13.

These developing devices 10 - 13 are fixed to a movable frame 9 , and the movable frame 9 is movable in the vertical direction by a moving mechanism 16 .

The moving mechanism 16 of the developing device 8 includes a stepping motor,
Bevel gear 17.1 connected to this stepping motor
8, a ball screw 19 fixed to the bevel gear 18 and extending in the vertical direction, and a NAND 20 fixed to the movable frame 9 and screwed into the ball screw 19.

A transfer drum 21 is arranged below the photosensitive drum 7 in close proximity to it. Further, above the photosensitive drum 7, a laser unit 22 is arranged. Laser unit 2
The laser beam from 2 is irradiated onto the upper end surface of the photoreceptor drum 7. On the other hand, below the document table 2, a reader 23 including a CCD element is arranged.

The reader 23 is driven in the left-right direction in the figure, and is capable of scanning a document placed on the document table 2.

The image information obtained by the reader 23 is transmitted to the laser unit 2
2 as an electrical signal.

A paper feed conveyance device 24.
25 are arranged. Each paper feed conveyance device z 24, 2
Reference numeral 5 includes a paper feed guide and a plurality of paper feed rollers. Between the transfer tram 21 and the paper discharge tray 4, a paper discharge conveyance device 26 and an image fixing device 27 are arranged in order from the transfer drum 2 side. A separation claw 28 for separating the recording paper on the transfer drum 21 from the transfer drum 21 is provided between the transfer drum 21 and the paper discharge conveyance device 26 .

Details of the transfer tram 21 are shown in FIGS. 2 to 5.

As shown in these figures, the transfer drum 21 includes ring-shaped rotating frames 30 and 31 at both ends, and both rotating shaft frames 30 and 31.
．． , 31. A transfer drum shaft 33 is inserted through the center of the ring-shaped rotating frame 30.31, and both ends of the drum shaft 33 are fixed to frames 34 and 35, respectively. One rotating frame 30 is rotatably supported by a bearing 37 attached to the frame 34 via a pin 36.

Note that a plurality of bearings 37 are provided at predetermined intervals in the circumferential direction. On the other hand, the rotating frame 31 has a boss portion 31 at the center.
a, and this boss portion 31a is rotatably supported by a bearing 38 on the drum shaft 33. Further, a gear portion 32a is formed on the outer periphery of the side end portion of the rotating frame 31, and this gear portion 32a meshes with a gear portion (not shown) of the photoreceptor drum 7.

A clipper 40 is provided on the upper surface of the stay 32, and rotating cams 41 and 42 are provided on the lower surface of the stay 32. Note that a structure similar to that shown in FIG. 3 is also provided on the rotating frame 30 side. That is, a total of four clippers 40 are provided, and a total of four rotating cams are provided corresponding to each clipper 40.

As shown in FIG. 4, the clipper 40 has a relatively wide paper presser section 40a in the center thereof, and has a paper presser section 40a having a relatively wide width.
It has paper push-up parts 40b at both ends of a. The paper push-up section 40b is formed to be inclined downward from the paper press-down section 40a. A support portion 40c is provided on the base side of these parts, and this support portion 40c is attached to the stay 3 with a pin or the like.
It is rotatably supported in a recess formed on the second side. A locking portion 40d having a circular cross section is formed on the lower surface of the support portion 40c so as to protrude downward. This locking portion 40d penetrates the stay 32 and projects inside the transfer drum 21.

On the other hand, the rotating cams 41 and 42 are each formed in an L-shape and are arranged symmetrically. Each bent portion is rotatably supported by the stay 32 via a pin 43.

Furthermore, protrusions 41b and 42b are formed at the ends of the long sides 41a and 42a, which are disposed along the rotational direction of the transfer drum, on opposite sides, respectively. In addition, short side portions 41c and 42 formed in a direction perpendicular to the rotation direction.
The tip of C has a bifurcated shape with notches 41d and 42d in the center, and a locking portion 40d of the clipper 40 is locked in the notches 41d and 42d. In addition, near the protrusions 41b and 42b of each rotating cam 41.42,
A pin 44 is provided to protrude upward, and the stay 32
The guide grooves 32a and 32b are inserted into arcuate guide grooves 32a and 32b. Then, on the upper surface of the stay 32, the pin 44
One end of a tension spring 45 is attached to the stay 32, and the other end of the tension spring 45 is attached to the stay 32.

In this way, the rotary cams 41 and 42 are rotatable around the axis (pin 43) that intersects the outer circumferential surface of the transfer drum 21, and normally the respective protrusions 41b are pulled by the tension springs 45. , 42b are biased toward each other.

Further, inside the transfer tram 21, a rotation shaft 46 is provided parallel to the drum shaft 33. The rotation shaft 46 is rotatably supported by a fixed subframe 47 inside the transfer drum 21 . As shown in FIG. 5, the rotation shaft 46 has a position W (lower part in the figure) where it grips the recording paper, and a position (upper part in the figure) almost opposite to this, that is, a position where the recording paper is separated from the transfer drum 2. are provided in each. This rotation axis 4
6 is provided with fixed side cams 48 and 53. As shown in FIG. 3, the fixed side cams 48 and 53 are
It is arranged so that it can come into contact with the protrusions 41b and 42b of 1.42. Both sides 48a, 48b of cam 48°53
53a and 53b are cam surfaces that restrict the rotation of the rotation cams 41 and 42, respectively, and are formed into an egg shape as a whole.

Note that the fixed side cam 48 provided at the recording paper separation position is
Its width is set larger than that of the cam 53 provided at the recording paper gripping position.

On the other hand, a posture control cam 49 is fixed to one end of the rotation shaft 46. One end of each attitude control cam 49 is biased in one direction by a spring 50, as shown in FIG.
Both ends of the attitude control plate 51 are in contact with the other end. The attitude control plate 51 is rotatable around the drum shaft 33, and is rotated counterclockwise in FIG. 5 by a solenoid 52. With the attitude control cam 49, the spring 50, the attitude control plate 51, and the solenoid 52, the fixed side cam 48.53 can be operated in the operating attitude shown by the solid line in FIG. It is now possible to take

Next, the operation will be explained.

When the print key is pressed, recording paper is fed from the paper feed cassette 5, and transferred to the transfer drum 21 by the paper feed conveyance device 24.
transported to the side. On the other hand, a predetermined developing device among the developing devices 10 to 13 is moved to the developing position. Next, the manuscript table 2
The image of the document placed thereon is read and a latent image is formed on the photoreceptor drum 7, and the latent image on the photoreceptor drum 7 is visualized by a developing device located at a developing position. This developed image is transferred onto recording paper wound around the transfer drum 21.

Here, the operation of winding the recording paper onto the transfer tram 21 will be explained. When the recording paper is supplied to the transfer t'' ram 1, the solenoid 52 is turned on and the attitude control plate 51 rotates counterclockwise in FIG. 5. Then,
The attitude control cam 49 is rotated clockwise by the lower end of the attitude control plate 51 against the biasing force of the spring 50.
The stationary cam 53 moves to the outer periphery of the transfer drum 21 via the rotation shaft 46 . In this state, when the transfer tram 21 rotates counterclockwise in FIG.
2b are cam surfaces 53a and 53b of the fixed side cam 53, respectively.
comes into contact with. As a result, each rotary cam 41, 42 has a pin 44 on its upper surface that is connected to the guide groove 32a, 32 of the stay 32.
b, and rotates against the biasing force of the tension spring 45. When each rotating cam 41, 42 rotates, it pushes the locking part 40d of the clipper 40, which is locked in the notch 41d, 42d, downward in FIG. Rotates away from the outer circumferential surface.

In this state, the recording paper is inserted between the paper pressing section 40a and the paper pushing up section 40b of the clipper 40. When the transfer drum 21 rotates and the protrusions 41b and 42b of the rotary cams 41 and 42 each pass the top (the part that protrudes most laterally) of the cam surface of the stationary cam 53, each protrusion 41b , 42b are urged toward each other by the tension spring 45, so that they gradually approach each other along the cam surfaces 53a, 53b of the fixed side cam 53.

As a result, the rotating cams 41, 42 rotate in the opposite direction to the above, and the locking portion 40d of the clipper 40 is moved upward in FIG. 3. Then, the clipper 40 rotates in a direction that presses the recording paper inside the transfer drum 21.

In this way, the movement of the rotating cams 41 and 42 is restricted along the cam surfaces 53a and 53b of the fixed side cam 53, so that the load on the drive system of the transfer tram 21 is prevented from drastically changing. There isn't. Note that when this recording paper gripping operation is completed, the solenoid 52 is turned off, and the posture control cam 49 is rotated counterclockwise by the spring 50. As a result, the rotating cam 53 assumes the retracted position.

In this way, the edge of the recording paper is gripped by the clipper 40 and the recording paper is wound around the transfer drum 21. and,
The images on the photosensitive drum 7 visualized by the developing devices 10 to 13 are successively transferred onto the recording paper. here,
The transfer tram 21 rotates at least four times while the images visualized by the developing devices 10 to 13 are being transferred.

At this time, if the fixed side cams 48.53 are in the operating position, this will hinder the transfer operation, so the solenoid 52 is not turned on during this time, and each fixed side cam 48.53 is maintained in the retracted position.

After the images formed by the developing devices 10 to 13 are transferred, the recording paper is separated from the transfer drum 21 and conveyed to the paper discharge conveying device 26 side.

When separating the recording paper from the transfer drum 21, the solenoid 52 is turned on in the same manner as described above, and the attitude control plate 5 is turned on.
1 in the 5th direction counterclockwise. Then, the upper end of the attitude control plate 51 pushes the upper end of the attitude control cam 49, thereby causing the attitude control cam 49 to rotate counterclockwise against the urging force of the spring 50. Then, the fixed side cam 48, which had been in the retracted position shown by the dashed line in the fifth
moves toward the outer peripheral surface of the transfer drum 21 and assumes the operating position.

In this state, the transfer drum 21 rotates and the stay 3
2 is attached to this fixed side cam 48 (then the rotating cams 41 and 42 rotate in the same manner as described above, and the clipper 40 rotates upward. At this time, the fixed side cam 48 is Since the width dimension of the clipper 40 is set wide, the push-up portions 40b at both ends of the clipper 40 touch the transfer drum 2.
It assumes a posture of protruding upward from the outer circumferential surface of 1. As a result, the recording paper separates from the outer peripheral surface of the transfer tram 21 and rides on the separation claw 28. When the transfer drum 21 further rotates in this state, the recording paper is guided by the separation claw 28 and separated from the transfer drum 21, and is sent to the paper discharge conveyance device 26 side.

When the transfer tram 21 rotates and the rotary cams 41.42 pass the tops of the fixed cams 48, each rotary cam 41.42 is moved by the biasing force of the tension spring 45 and by the shape of the cam surfaces 48a, 48b of the cams 48. It gradually rotates in the opposite direction along the arrow , and returns to its original position as shown in FIG. At the same time, the solenoid 52 is also turned off, the attitude control cam 49 is rotated by the spring 50 in the opposite direction, and the fixed side cam 48 is in the retracted attitude.

In such an embodiment, the clipper 40 is opened and closed by rotating cams 41, 42, and the rotating cams 41, 42
The rotation of 42 is regulated by the fixed side cam 4. In particular, when the clipper 40 closes, the rotating cams 41 and 42
The protrusions 41b, 42b are brought into contact with the stationary cams 4B, 53 to restrict their movement, so the load on the drive system of the transfer drum 21 does not vary significantly, resulting in good transfer performance. Problems such as color shift can be prevented.

[Other Examples]

(al) In the above embodiment, in the fixed side cam 48.53, the distances from the cam center to the cam surfaces 48a, 53a and from the cam center to the cam surfaces 48b, 53b are always the same, and the center Although the lifting heights of the side clippers 40 and the outside clippers 40 are set to be the same, the lifting heights may be changed by each clipper by changing the distance from the center of each cam surface.

(b) In the above embodiment, one fixed side cam 48 or 5
3, the two rotating cams 41 and 42 are rotated, but separate fixed side cams may be provided corresponding to the respective rotating cams 41 and 42.

(C) In the above embodiment, either the protrusions 41b and 42b of the rotary cam 41.42 are brought into contact with the fixed side cam 48.53 to restrict its movement, or the lower surface of the rotary cam 41.42 is A protruding pin may be provided, a guide groove that engages with the pin may be formed in the fixed side cam 48, 53, and the movement of the rotating cams 41, 42 may be restricted by these engagements.

(d) In the above embodiment, a transfer drum was used as an example of the transfer device, but the present invention can be similarly applied to a transfer device composed of a roller, a heald, and the like.

〔Effect of the invention〕

As described above, in the present invention, the movement of the clipper during the opening/closing operation is regulated by the movement of members such as cams, so that the movement of the clipper and the members that move it become smooth, and load fluctuations in the drive system are reduced. Therefore, the quality of the formed image can be improved.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional view of a full-color copying machine employing an embodiment of the present invention, FIG. 2 is a front view of a transfer device according to an embodiment of the present invention, and FIG. 3 is a partial plan view thereof. FIG. 4 is a perspective view of the clipper, FIG. 5 is a diagram showing the opening/closing operation control mechanism of the clipper, and FIG. 6 is a perspective view of a conventional clip device. 21...Transfer tram, 40...Clipper, 40.
...Paper presser section, 40b...Paper push-up section, 40d...
- Locking part, 4], 42... Rotating cam, 41b, 42b
...Protrusion, 45...Tension spring, 48.53.
・Fixed side cam, 48a, 48b, 53a, 53b・=
cam surface. Patent applicant Mita Kogyo Co., Ltd. Agent Patent attorney Mitsuo Ono Yama

Claims (1)

[Claims] (1) A clip device for holding the recording sheet on the outer peripheral surface of the transfer device and separating the recording sheet from the transfer device, the clip device being provided on the outer peripheral portion of the transfer device so as to be openable and closable, and having a clip at the leading end of the recording sheet. A transfer device comprising: a clipper for gripping the clipper; a clipper opening/closing means provided in the transfer device for opening and closing the clipper; and a regulating means for regulating opening and closing operations of the clipper by the clipper opening/closing means. clip device.