JPS62259954A - Retractor - Google Patents

Abstract

PURPOSE:To check the extent of vibration and noise in a retractor as well as to smooth its operation, by operating two cams with one motor, and making the sum total of force working on these two cams so as to come smaller, in case of the retractor for a transcriber unit and a paper guide in a copying machine. CONSTITUTION:When a motor 14 is rotated, a cam shaft 20 is drive into rotation via a coupling 15. With rotation of the cam shaft 20, a paper guide cam 18 and a transcriber cam 19 both are rotated and thereby a transcriber 8 and a paper guide 7 are driven each via cam followers 22 and 22'. Each form of the paper guide cam 18 and the transcriber cam 19 is formed by a cycloid curve. Therefore, each movement of these cam followers 22 and 22' becomes very smooth. Now, when a gripper 6 is advanced up to short of the paper guide, the transcriber unit 8 and the paper guide 7, receiving signal out of a controller (unillustrated herein), once go down but, after the gripper 6 passes through the transcriber unit 8, they go up again.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a retracting device for a transfer unit or a paper guide in a copying machine or a digital printer.
In particular, the present invention relates to a retracting device for retracting a transfer unit and a paper guide as the gripper moves in a copying machine that uses a gripper such as a chain gripper as a paper conveyance device.

[Conventional technology]

2. Description of the Related Art When conveying paper in an electronic copying machine, a digital printer, or the like, there is a method in which the leading edge of the paper being conveyed is held between grippers and conveyed. This method is widely used because the paper can be transported reliably.

However, in order to convey paper using a gripper, it is necessary to pass a relatively thick gripper through a narrow gap.

FIGS. 4 and 5 are diagrams showing the photoreceptor and its surroundings. In the figure, 1 is a photoreceptor, and around it, an optical system for applying exposure 2, a developing device 4, a pre-transfer static eliminator 5, a transfer device unit 8, etc. are arranged, and a charger 3, an eraser 12, etc. , a pre-cleaning static eliminator 10, a cleaning unit 11, and a paper guide 7 are installed. A paper conveyance chain 9 is provided with a gripper 6, and passes between the transfer device unit 8 and the photoreceptor 1 while holding the paper therebetween. At this time, there must be a sufficient gap between the gripper 6 and the photoreceptor 1 so that the gripper 6 can pass therethrough. Further, as shown in an enlarged view in FIG. 5, the copy paper 40 held by the gripper 6 is pushed upward by a paper guide 7 provided below along the surface of the photoreceptor 1, and is transferred. The container unit 8 is also raised upward from the position 8'. This is very effective in improving the transferred image.

Therefore, when the gripper 6 passes through this part, the transfer device unit 8 and paper guide 7 are housed at the positions 8' and 7', respectively, and when the image on the photoreceptor is transferred to the paper, It needs to be in the .7 position. A mechanism for raising and lowering the transfer unit 8, paper guide 7, etc. is a retract device.

Conventionally, a solenoid has been used to retract the transfer unit 8 and paper guide 7. That is, before the gripper 6 reaches the paper guide 7, the paper guide 7 and the transfer unit 8 are energized by the solenoid.
Pull down so that there is no obstruction to the passage of gripper 6. Immediately after the gripper 6 passes, the solenoid is de-energized and the paper guide 7 and transfer unit 8
is set at the position indicated by the solid line in FIG. The paper 40 comes into close contact with the surface of the photoreceptor 1, allowing stable transfer.

[Problem that the invention seeks to solve]

Since such conventional devices use a solenoid for the retract mechanism, noise is generated when the solenoid is driven, and the impact caused by this drive can damage the paper gripper,
There was a problem in that the paper etc. vibrated, causing disturbances in the transferred image.

This invention was made to solve these problems, and suppresses vibrations during operation of the retract mechanism.
The purpose of the present invention is to provide a retracting device that reduces noise and enables smooth operation.

[Means and operations for solving the problem] In order to solve the above problem, in this invention, a plurality of cams are operated by one drive motor, and the sum of the forces acting on the plurality of cams is reduced. It is characterized by using a retract mechanism.

As a result, - vibration of the retract mechanism is suppressed, noise is reduced, and smooth retract movement is realized.

〔Example〕

1, 2, and 3 are views showing one embodiment of the present invention, and FIG. 1 is a perspective view of the main parts of the paper guide 7, the transfer unit 8, and the retracting device that drives them. Figure 2 shows the shape of the paper guide cam and transfer unit (corotron) cam, which are one of the components of the retracting device, and Figure 3 shows the cam part shown in Figure 1 viewed from above. shows.

In FIG. 1, 9.9' is a chain, and the gripper 6 as described above is fixed to this chain 9.9'. The chain 9.9' moves the gripper 6 in the direction of the arrow. 7 is a paper guide, which is fixed to the paper guide shaft 23. The shaft 23 is engaged with the paper guide cam 18 via a cam arm 21 and a cam follower 22. 8 is a transfer unit;
It is coupled to the transfer shaft 24 via a transfer arm 25 . A cam arm 21' is attached to the transfer device shaft 24.
, are engaged with the transfer device cam 19 via a cam follower 22'. Paper guide cam 18, transfer device cam 1
9 are connected to a cam shirt 20 and connected to a drive motor 14 via a coupling 15. The drive motor 14 may be, for example, a stamping motor.

Reference numeral 16 denotes a home position disk for determining the rotational home positions of the paper guide cam 18 and the transfer device cam 19, and a sensor 17 is placed opposite to this.

When the motor 14 rotates, the camshaft 20 is rotationally driven via the camp ring 15. Cam shirt 1-20
As a result of the rotation, the paper guide cam 18 and the transfer device cam 19 rotate, and the transfer device 8 and paper guide 7 are respectively driven via the cam followers 22 and 22'.

The paper guide shaft 23 and the transfer device shaft 24 are biased in advance in the directions of arrows c and c', respectively, and normally the paper guide shaft 7 and transfer device 8 are biased in the direction of the broken line 7' in FIG.
, 8'. When the motor 14 rotates, it will also be placed at the position indicated by the solid line in FIG.

When the paper is held by the gripper 6 and comes to the paper guide 7, the paper guide 7 is lowered downward, and when the gripper 6 comes to the transfer unit 8,
The transfer device unit 8 has also sunk downward. When the gripper 6 passes the transfer unit 8, the motor 14 is driven to drive the paper guide 7 and the transfer unit 8 to the position shown by the solid line in FIG. By doing this, the transfer tuffing point will always be constant, thereby making it possible to make high-quality copies.

FIG. 2 shows the paper guide cam 18 and the transfer device cam 1.
FIG. 9 is a diagram showing the shape of No. 9; The paper guide cam 18 has a large diameter arc R1, a small diameter arc R2, and their arc R1.
, R2 (Bestehorn sine curve) Sl, S2, the transfer device cam 19 is formed by a large diameter arc R3, a small diameter arc R4, and a cycloid curve connecting these arcs R3 and R4. It is composed of S3 and S4. Accordingly, as the camshaft 20 rotates, the cam followers 22, 22' reciprocate between the large diameter section R1 and the small diameter section R2, and between the large diameter section R3 and the small diameter section R4, respectively. Since the large diameter portion and the small diameter portion are connected by a cycloid curve, the movement of the cam followers 22, 22' is extremely smooth.

In addition, as shown in Fig. 2, the cam follower 22.22
Let the forces at the contact point with the cam of ' be Wl and W2, respectively, and the distance between these forces W1 and W2 and the camshaft 20 be 11.12, then Wl・11″qW2・J2 --
--------・Make sure that (1) holds true.

Of course, the cam profile, cam lift, cam arm length, cam arm fulcrum position, cam follower diameter, and camshaft position are set in various ways depending on the design conditions, so accurate design is required for formula (1) to hold true. However, if the equation (1) is approximately satisfied, the load on the camshaft 20 can be reduced accordingly. In order to satisfy this condition, in this invention, the paper guide cam 1
8. Two cams of the transfer device cam 19 are arranged to face each other.

Now, when the gripper 6 is moving in the direction of the arrow, the paper guide cam 18 and the transfer device cam 19 are stopped at a fixed position by the home position disk 16. When gripper 6 has advanced to the front of the paper guide,
In response to a signal from a controller (not shown), the paper guide 7 and transfer unit 8 are lowered (if they are originally lowered, they remain in that state), and after the gripper 6 passes the transfer unit 8, they are raised. All of this series of operations is performed by inputting a timing signal from the controller to the drive motor 14.

A two-phase (1.8° step) stepping motor was used in this example.

The two cam operations repeat the following operations: normal position - 180° rotation (100 steps progress) - stop - 180° rotation (normal position 100 steps progress), and retraction is repeated as the gripper moves.

If you want to slightly shift the timing of raising and lowering the paper guide 7 and transfer unit 8, just loosen the center screws of each cam and adjust the mounting position of each cam.

In addition, in FIG. 3, 27 is a top collar, and 28 is a Corotron cam fixing key.

In this embodiment, the details have been explained for the case where there is only one photoreceptor, but it goes without saying that the present invention can also be applied to a case where a plurality of photoreceptors are arranged in tandem, and also to a digital printer or the like.

In the embodiments described above, the gripper is a normal gripper,
For example, a gripper using spring pressure is used, but a gripper as shown below may also be used.

FIG. 6 is a diagram showing one example. 51.5 in the figure
1' is a chain (see FIG. 6(d)), and is provided with a gripper 52 for holding the paper. The chains 51, 51' form a closed loop, and these two
A gripper 52 is provided to connect two chains 51, 51'.

It goes without saying that the gripper 7 bar 52 is not limited to one but may be provided in a plural number.
As shown in FIG. 2, it is fixed to a gripper shaft 56 that is rotatably fixed to a gripper chassis 58. An opening/closing lever 53 is fixed to the end of this shaft 56, and a weight 59 is attached to the tip of the lever 53. is fixed. As the lever 53 moves up and down, the gripper 52 fixed to the shaft 56 opens and closes up and down.

In FIG. 6(a), it is assumed that paper is fed from the paper feed side. When the gripper 52 is on the paper feed side, the lever 5
3 is pushed upward by the rail 50, rotating the shaft 56 and opening the gripper 52, into which the paper is inserted. When the chain 51, 51' further advances in the direction of arrow F, the lower end of the lever 53 comes off the rail 50, so the gripper 52 is closed by the overlap 59 and the paper is sandwiched. The gripper 52 moves along with the movement of the chains 51 and 51', holding the paper between them, and
Receive treatment such as image transfer and fixation. When the gripper 52 comes to the paper discharge side and the lower end of the lever 53 rides on the rail 50', the gripper 52 opens again and releases the paper. The paper is released from the gripper and advances to the next stage, and the gripper 52 is sent back to the paper feed side through the underside. In addition, Fig. 6 (
C) is a view of the gripper from below.

FIG. 7 shows another example of the gripper. In FIG. 7(a), 60 is a chain, and a gripper 62 held by a chassis 61 is attached to this chain.

The gripper 62 is normally in the closed position due to the spring 63, but is opened via the lever 64 by the energization of the solenoid 65. FIGS. 7(B) and 7(C) are enlarged views showing the vicinity of this solenoid. At the bottom of the solenoid 65, a contact 67 is provided on the support plate 66, and a part of the contact 67 is provided on the support plate 66.
It is set up so that you can go outside. On the other hand, solenoid 65
energize the position where you want the gripper 62 to open, for example,
An electrode 70 connected to a power source 71 is arranged on the support plate 69 at the location where the sprocket shaft 68 is provided, and when the gripper 62 comes to this position, the contact 67
The electrode 70 is configured to be in contact with the electrode 70 . Thus, when the gripper 62 is in this position, the solenoid 65 is energized and the gripper 62 is opened.

FIG. 8 is a detailed view of the gripper 62 shown in FIG. 7.

The tip of the spring 63 is inserted into a notch 80 in the chassis 61, and the gripper 62 and lever 64 are fixed to the support shaft 81. When the plunger 82 is attracted in the direction of arrow A by the solenoid 65, the support shaft 81 rotates in the direction of arrow A, opening the gripper, and when the plunger 82 is discharged in the direction of arrow B, the gripper is closed.

〔Effect of the invention〕

As described above, according to the retracting device according to the present invention, one motor moves two cams at the same time, and since the cam has a cycloidal profile, a smooth retracting operation can be obtained. Vibration and noise are suppressed. Moreover, since the cams are arranged so as to face each other so that the sum of the moments becomes approximately zero, it is possible to perform the retracting operation sufficiently with one drive motor. Therefore, a stable and high quality transferred image can be obtained.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an embodiment of the retracting device of the present invention, Fig. 2 is a diagram showing a cam, Fig. 3 is a plan view of the periphery of the cam in Fig. 1, and Figs. 4 and 5 are photosensitizers. Figures 6, 7, and 8 showing the state of the body and its peripheral devices are diagrams showing examples of grippers. 1-Photoconductor, 2--Exposure, 3-Charger, 4--Developer, 5-Pre-transfer static eliminator, 6-Gripper, 7--Paper guide, 8--Transfer unit, 9
-Chain, 10-Pre-cleaning static eliminator, LL---・Cleaning unit, 12-Erase, 13-・Photoconductor rotation direction, 14
- Drive motor, 15- Coupling, 16- Home positive silane disc, 17- Sensor, 18- Paper guide cam,

Claims (3)

[Claims] (1) A retracting device that transports paper while being held by a chain gripper and retracts a transfer unit and a paper guide according to the movement of the chain gripper, which includes one drive motor and a drive motor driven by the drive motor. Two cams are provided, and the two cams are provided.
A retracting device characterized in that two cams are arranged in opposing positions so that the sum of moments acting on the two cams becomes approximately zero. (2) The retracting device according to claim 1, characterized in that the mounting position of the cam is variable. (3) The retracting device according to claim 1, wherein the home position of the cam is detected by a home position disk and a sensor.