JPH07115762B2 - Automatic paper feeder - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic sheet feeding device, and more particularly to a clutch device thereof.

[Conventional technology]

Generally, an automatic paper feeder that is removably attached to a printer includes a paper feed roller that holds a paper between a pressure plate and a pressing spring, and the paper feed roller is inserted from a platen of the printer through a gear train. The rotational force is transmitted.

Then, the paper stored in the hopper of the automatic paper feeder is sent to the printing unit of the printer by the rotation of the platen, is printed, and is discharged, but when the paper is sent to the platen, the platen is rotated normally. At the time when the specified amount of paper has been sent (paper feeding process),
It is necessary to reverse the platen to return the paper and align the paper to adjust the paper feeding direction (alignment step), and then again rotate the platen forward to feed the paper and print (printing step). A clutch device is required to perform the paper feeding operation and the release thereof by interlocking the operations of the paper feeding step, the aligning step, and the printing step with the forward / reverse rotation of the platen. For example, Japanese Utility Model Laid-Open No. 62-163331. The clutch device of the automatic paper feeder shown in the official gazette is disclosed. This clutch device is incorporated in a gear train arranged on the outside of the side plate of the automatic paper feeding device, and is configured to rotate the paper feeding roller in the normal direction in response to the normal rotation and reverse rotation of the platen and to disconnect the drive from the platen. .

[Problems to be Solved by the Invention]

However, in the conventional automatic paper feeder, the platen is rotated in the forward direction in the printing process in which the paper is returned and the paper after aligning the paper is fed. The drive connection from the is cut off, and the paper is pulled out from the hopper. At that time, the paper feed roller is always brought into contact with the paper to be swung around, but the paper feed roller made of rubber has a large friction coefficient and is worn and deteriorated. There is a possibility that the feeding of the paper in the paper process may become uncertain.

The present invention has been made to solve the above-described problems, and an object thereof is to provide an automatic paper feeding device capable of preventing abrasion and deterioration of a paper feeding roller and reduction of a friction coefficient due to paper dust. Is.

[Means for Solving the Problems]

In order to achieve the above object, the present invention is a paper feed roller that is detachably attached to a printer, communicates with a drive shaft of the printer through a paper feed roller shaft, and rotates in synchronization with forward and reverse rotation of the printer drive shaft. And a hopper having a pressure plate for pressing the stacked sheets against the sheet feeding roller,
In an automatic paper feeder that separates the uppermost sheets of paper stacked in a hopper one by one and sequentially feeds them to a printer, an auxiliary roller arm rotatably attached to a paper feed roller shaft,
An auxiliary roller that is axially supported by the auxiliary roller arm and comes into contact with the paper, a clutch disc that is integrally attached to the auxiliary roller arm and is rotatably attached to the paper feed roller shaft, and is attached to the side plate of the hopper. It is placed between the ratchet pawl that is in sliding contact with the outer peripheral surface, the clutch disc and the side plate of the hopper, and is locked by the paper feed roller when the paper feed roller rotates in the reverse direction and feeds when the paper feed roller rotates in the normal direction. A one-way clutch having an operating rod at one end that is unlocked by the roller and multiple ends being free ends; and an arm stopper that prevents rotation of the auxiliary roller arm within the rotation trajectory of the auxiliary roller arm, A partition wall extending in the circumferential direction is formed on the outer peripheral surface of the clutch disc, and the tips of the ratchet pawls are provided on both sides of the partition wall when the paper feed roller is normally rotated. A clutch-on pawl guide passage that stops and a clutch-off pawl guide passage that bypasses the ratchet pawl are formed, and a guide surface that guides the ratchet pawl to the clutch-on pawl guide passage is formed at one end of the partition wall. A guide surface for guiding the ratchet pawl to the clutch-off pawl guide passage is formed at the other end, and the clutch disc has a reverse rotation preventing stopper and a one-way clutch for preventing reverse rotation of the operating rod of the one-way clutch in the reverse direction. A normal rotation preventing stopper is provided for preventing the normal rotation of the operating rod in the normal rotation direction.

[Work]

In the present invention, the steps from the rotation of the drive shaft of the printer being selectively transmitted to the auxiliary roller arm to the normal rotation of the feed roller to the normal rotation of the paper feed roller to separate the paper from the hopper and feed it to the platen. Except for this, the auxiliary roller arm is swung, and the auxiliary roller is brought into contact with the paper when rotating in the direction of the pressure plate. By the contact of the auxiliary roller with the sheet, the sheet is retracted against the pressing force of the pressure plate of the hopper, and the sheet is separated and held from the sheet feeding roller.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

An automatic sheet feeder according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3, 5 and 13 to 15.

1 to 3, reference numeral 1 denotes an automatic sheet feeder according to the present embodiment, which is configured to be detachably attached to a printer 2 and has a hopper 3 for storing sheets. is doing. Side plate 4 of hopper 3
Further, the sleeve 5 is rotatably engaged with and fixed to the inside thereof.

A linear projection 5B is formed on the inner cylinder portion 5A of the sleeve 5, and the paper feed roller shaft 6 penetrates the inner cylinder portion 5A. A shaft groove 6A is formed on the outer peripheral surface of the paper feed roller shaft 6 along the axial direction, and a linear protrusion 5B is engaged with the shaft groove 6A along the axial direction. The sleeve 5 slides and can move in the axial direction, and can rotate integrally with the paper feed roller shaft 6.

A paper feed roller 7 is integrally fixed to the outer peripheral surface of the sleeve 5. With this configuration, the sheet feeding roller 7 and the clutch device C described below integrally follow the movement of the side plate 4 in determining the width.

In FIG. 5, reference numeral 8 is a pressure plate for stacking sheets, which is pressed by a pressing spring 9 provided in the hopper 3.

In FIG. 1, a platen 10 of the printer 2 is fixed to a drive shaft 11 rotatably mounted on the printer 2, and a drive gear 12 is provided at one end of the drive shaft 11. Drive gear
The gear 12 is connected to a paper feed roller gear 14 attached to the end of the paper feed roller shaft 6 via a gear train 13.

In FIGS. 1 to 3, on the outer peripheral surface of the sleeve 5,
A clutch disc 15 is loosely fitted to the right of the paper feed roller 7, and the auxiliary disc arm 16 is attached to the clutch disc 15.
Is integrally attached to one end of the auxiliary roller arm 16, and an auxiliary roller 16A that can come into contact with the paper is rotatably supported at one end of the auxiliary roller arm 16. It is freely rotatable.

A one-way clutch consisting of a spring clutch 17 in a press-fit state is provided between the sleeve 5 and the clutch disc 15,
The spring clutch 17 is locked by the sleeve 5 when the paper feed roller shaft 6 rotates in the reverse direction and unlocked by the sleeve 5 when the paper feed roller shaft 6 rotates normally, and has an operating rod 17A at one end and the other end. Is a free end.

The clutch disc 15 includes a reverse rotation prevention stopper 18A for preventing the operating rod 17A of the spring clutch 17 from rotating in the reverse direction and a forward rotation prevention for preventing the operating rod 17A of the spring clutch 17 from rotating in the normal direction. Is provided with a stopper 18B.

Further, the hopper 3 is provided with an arm stopper 19 for blocking the rotation of the auxiliary roller arm 16 within the locus range of the auxiliary roller arm 16.

A ratchet pawl 20 is rotatably attached to the side plate 4, and is biased to the clutch disc 15 by a coil spring 21.

The structure of the clutch disc 15 is shown in FIGS.
It will be described with reference to FIG. It should be noted that FIGS. 10, 13, and 17 are written from the position where the ratchet pawl 20 moves relative to the clutch disc 15, and are shown in FIGS. 11, 12, 14 to 16, 18 to 21 are written from the position in which the clutch disc 15 rotates with respect to the ratchet pawl 20.

In FIGS. 13 to 15, a partition wall 21 extending in the circumferential direction is formed on the outer peripheral surface 15A of the clutch disc 15, and a locking portion for locking the tips of the ratchet pawls 20 on both sides of the partition wall 21. A guide portion 23 is formed by which the tip of the ratchet pawl 20 and the tip of the ratchet pawl 20 bypass. Furthermore, on the outer peripheral surface 15A, a guide step portion 24 that guides the tip of the ratchet pawl 20 to the rising portion 23A of the guide portion 23 is formed continuously from the locking portion 22,
A guide step portion 25 that guides the tip of the ratchet pawl 20 to the engaging portion 22 is formed continuously with the tip portion 23B of the guide portion 23.

By biasing the tip of the ratchet pawl 20 against the outer peripheral surface 15A of the clutch disc 15 to rotate the clutch disc 15 in the forward and reverse directions as described later, the engagement portion 22 is in the locked state at the end of the forward rotation of the printing process. The guide portion 23 is bypassed during the forward rotation of the sheet feeding process thereafter, and the lock portion 22 is guided to return to the locked state during the reverse rotation of the aligning process. The locking portion 22 is held in a locked state during normal rotation of the platen 10 in the printing process.

In FIG. 5, 10A indicates a pinch roller provided so as to face the platen 10, and 10B indicates a PE sensor for detecting the leading edge of the paper.

Next, the operation of this embodiment will be described with reference to FIG. 4, FIG. 5 to FIG.
This will be described with reference to FIGS. 10 to 21.

In the present embodiment, in the operation of the automatic paper feeder 1,
The first step, the second step, the third step, the fourth step, and the fifth step shown in the lower part of FIG. 4 proceed in this order, and when the fifth step is completed, the process returns to the first step, and these steps are repeated. Then, the paper is sent from the automatic paper feeder 1 to the printer 2, printed, and discharged.

Here, the first step (shown in FIG. 5) is to print the previous sheet.
When the second step (shown in FIG. 6) is in the platen state,
10 is a preparatory step for reversing by a predetermined angle, the third step (shown in FIG. 7) is a paper feed step, the fourth step (shown in FIG. 8) is an alignment step, and the fifth step (shown in FIG. 9) is a print step. Paper feeding, printing,
A printing process for discharging a sheet will be described.

In the following, description will be given in order of each process assuming that the state of the first process is secured in a state where the initialization of the clutch device C described later is completed.

First, as shown in FIG. 5, in the first step, the printing and discharging of the previous sheet are completed, and the spring clutch
The operating rod 17A of 17 is in contact with the forward rotation preventing stopper 18B of the clutch disc 15, and the auxiliary roller 16A is pressed against the paper and is in contact therewith. The auxiliary roller 16A receives a pressing force from the pressing spring 9 via the paper, and thereby the clutch disc 15 integrated with the auxiliary roller arm 16 tries to rotate in the forward rotation direction, but the engaging portion 22 of the clutch disc 15 does not rotate. Since the tip of the ratchet pawl 20 is locked (shown in FIGS. 10 to 12), the rotation of the clutch disc 15 is blocked and the auxiliary roller 16A is in the position shown in the figure.

As shown in FIG. 6, in the second step, the printer 2
When the platen 10 of is reversed by a predetermined angle (N rows), the platen
Rotational force is transmitted from 10 to the paper feed roller shaft 6 through the gear train 13, and the paper feed roller shaft 6 is reversed by a predetermined angle (about α + β angle).

The reverse rotation of the paper feed roller shaft 6 causes the spring clutch 17 press-fitted into the sleeve 5 to rotate in the reverse rotation direction. Due to the press-fitting resistance between the sleeve 5 and the spring clutch 17, the operating rod 17 of the spring clutch 17 reaches from the forward rotation prevention stopper 18B to the reverse rotation prevention stopper 18A, reverses the α angle, and locks between the spring clutch 17 and the sleeve 5. To be done.

Therefore, by further rotating the paper feed roller shaft 6 by β angle,
Actuating rod of spring clutch 17 locked to sleeve 5
The reverse rotation preventing stopper 18A is further rotated by β angle by 17A, and the auxiliary roller arm 16 integrated with the clutch disc 15 is further rotated by β angle in the counterclockwise direction.

By the counterclockwise rotation of the auxiliary roller arm 16 at the β angle, the sheets stacked on the pressure plate 8 are pressed by the auxiliary roller 16A and moved backward against the urging force of the pressing spring 9.

As the clutch disc 15 rotates in the reverse direction, the engaging portion 22 of the clutch disc 15 in the engaged state of the first step escapes to the tip of the ratchet pawl 20, and the state shown in FIG.
The locking is released when the state shown in FIGS. 14 and 16 is reached.

As shown in FIG. 7, in the third step, the platen 10
When the sheet rotates in the reverse direction and rotates in the normal direction, the sleeve 5 rotates in the normal direction together with the feed roller shaft 6.

The spring clutch 17 press-fitted into the sleeve 5 receives the press-fitting resistance, and the operating rod 17A of the spring clutch 17 makes a predetermined angle (α angle) forward rotation from the reverse rotation prevention stop 18A and contacts the forward rotation prevention stopper 18B. The press-fitting resistance causes the operating rod 17A to rotate the forward rotation preventing stopper 18B in the forward rotation direction (clockwise direction), and the auxiliary roller arm 16 integrated with the clutch disc 15 also rotates in the forward rotation direction (clockwise direction). It rotates by an angle γ and comes into contact with the arm stopper 19 to prevent the rotation.

During this time, the tip of the ratchet pawl 20 that moves relative to the clutch disc 15 is guided to the guide step portion 24 of the clutch disc 15 and then bypasses the guide portion 23, as shown in FIG. That is, the tip of the ratchet pawl 20 is the ratchet pawl 20 shown by the solid line in FIG. 13, from FIG. 14 and FIG.
The ratchet pawl 20 shown by the chain double-dashed line in the figure reaches the state shown in FIG. Furthermore, the tip of the ratchet claw 20 is bypassed to the 17th
The ratchet pawl 20 shown by the solid line in the figure reaches the state shown in FIGS. 18 and 20.

And between the sleeve 5 and the spring clutch 17,
Even if the auxiliary roller arm 16 is prevented from rotating by the arm stopper 19, the spring clutch 17 is not locked by the sleeve 5 (free rotation in the forward rotation direction) and slips, so that in the subsequent forward rotation, the paper feed roller Only 7 continues to rotate normally.

Since the auxiliary roller 16A escapes from the paper by the rotation angle γ of the auxiliary roller arm 16, the paper is advanced by the urging force of the pressing spring 9 and comes into contact with the paper feed roller 7.

Therefore, as the paper feed roller 7 continues to rotate normally, the paper is
After one sheet is separated from the hopper 3 and fed to the platen 10 by a predetermined amount, it is pinched between the platen 10 and the pinch roller 10A, and the PE sensor 10B detects the leading edge of the sheet.

This signal stops the normal rotation of the platen 10.

As shown in FIG. 8, in the fourth step (alignment step), the platen 10 stops forward rotation in response to a signal from the PE sensor 10B and then starts reverse rotation.

First, the reverse rotation of the platen 10 causes the sleeve 5 together with the paper feed roller shaft 6 to reverse by an α angle, and the frictional force causes the spring clutch 17 to reversely rotate so that the operating rod 17A moves from the forward rotation prevention stopper 18B to the reverse rotation prevention stopper 18A. Come into contact with.

After the contact, the sleeve 5 and the spring clutch 17 are locked, and the paper feed roller shaft 6 moves to the spring clutch 17,
The auxiliary roller arm 16 which receives the reverse rotation force via the clutch disc 15 is rotated in the reverse rotation direction (counterclockwise direction) by the rotation angle γ.

At this time, the reverse rotation of the platen 10 also reverses the paper feed roller 7, so that the paper is returned by the platen 10 and the paper feed roller 7. On the other hand, the auxiliary roller 16A first comes into contact with the paper and further in the reverse rotation direction in that state. To the turning angle γ.

Further, the auxiliary roller arm 16 is rotated to press and retract the sheet, the contact between the sheet feeding roller 7 and the sheet is broken, and the return is stopped. Since the platen 10 continues to return the sheet even during this time, the sheet is bent between the platen 10 and the auxiliary roller 16A, and the sheet is aligned in the feeding direction.

That is, the leading edge of the paper is the platen 10 and the pinch roller 10A.
Is swept up to the tangent portion of the sheet, and the elastic force of the bending of the sheet formed at this time aligns the sheet with the tangent portion of the platen 10 and the pinch roller 10A so that the sheet is correctly positioned and aligned in the feeding direction.

During this time, the tip of the ratchet pawl 20 that moves relative to the clutch disc 15 is guided by the guide step 25 in FIG. 17, and the state of the ratchet pawl 20 shown by the solid line in FIG.
From the state shown in the figure, through the state of the ratchet pawl 20 shown by the chain double-dashed line in FIGS. 17 and 19 and the state shown in FIG. 21, the engagement with the engagement part 22 is reached (FIGS. 10 and 11). Return to the state of). In short, at the end of this aligning step, the locking portion 22 of the clutch disc 15 is guided by the tip of the ratchet pawl 20 to be in the locked state.

As shown in FIG. 9, in the fifth step (printing step), when the platen 10 rotates in the normal direction after the alignment of the sheets in the fourth step, the sheet is again pinched at the tangent portion between the platen 10 and the pinch roller 10A. It is rarely sent to the printing unit of the printer 2 again.

The feed roller shaft 6 is rotated normally by the normal rotation of the platen 10, and the operating rod 17A of the spring clutch 17 is normally rotated by a predetermined angle (α angle) from the reverse rotation prevention stopper 18A to the normal rotation prevention stopper 18B.
However, since the tip of the ratchet pawl 20 is in a state of being locked by the locking portion 22 of the clutch disk 15, the clutch disk 17 cannot be rotated in the forward direction.

Since the operating rod 17A of the spring clutch 17 comes into contact with the forward rotation preventing stopper 18B of the clutch disc 17 which is stopped and locked without rotating in the forward direction and does not rotate, a slip occurs between the sleeve 5 and the spring clutch 17. (Spring clutch 17 is free in the forward direction).

Although the paper feed roller 7 continues to rotate in the normal direction, since the auxiliary roller 16A presses the paper and is retracted, there is no contact between the paper feed roller 7 and the paper, and the paper feed force by the auxiliary roller 7 does not act.

Therefore, the sheet is sent by the normal rotation of the platen 10, but the trailing edge of the sheet is pulled out only by the light resistance of the auxiliary roller 16A and printing is continued.

It is necessary to initialize the clutch device C before performing the above-mentioned repeated steps from the first step to the fifth step,
For that purpose, the procedure K shown in the upper part of FIG. 4 is executed as follows.

First, the platen 10 is rotated forward by M lines, and the first sheet of paper is
If it is in the third step, the platen 10 is in the normal rotation of the M line,
The paper is separated and fed by the paper feed roller 7, and the tip of the paper is pinched by the platen 10 and the pinch roller 10A, and the PE sensor 1
A signal is input to 0B, the PE sensor 10B is turned on, and the process proceeds to the fourth and fifth steps.

When the paper feed roller 7 and the paper are not in contact with each other as in the first process and the second process, the paper is not fed even if the platen 10 is normally rotated by M rows, and the PE sensor 10B is turned off. If this state is still judged by the control device (not shown), the process proceeds from the Nth row reverse rotation of the second process to the third process.

According to the above-described structure, the clutch device C causes the auxiliary roller 16A to contact the sheet, and the sheet stacked on the pressure plate 8 is retracted against the pressing force of the pressing spring 9. Since the sheet 7 and the sheet are separated from each other, the sheet feeding roller 7 does not come into contact with the sheet when the sheet is pulled out, and the auxiliary roller 16A simply rotates around when the sheet is pulled out. The pull-out force can be reduced, and it is possible to prevent wear and deterioration of the paper feed roller 7 and reduction of the friction coefficient due to paper dust.

Further, since the clutch device C is arranged inside the side plate 4 of the hopper 3 of the automatic paper feeding device 1 and it is not necessary to intermittently rotate the paper feeding roller 7, the structure of the clutch device C is simplified and the entire device is The width of can be reduced.

〔The invention's effect〕

As described above, according to the present invention, the auxiliary roller comes into contact with the paper, and the paper stacked on the pressure plate retracts against the pressing biasing force, so that the paper feed roller and the paper are separated from each other. Since it is in the state where the paper is pulled out, the paper feed roller and the paper do not come into contact with each other when the paper is pulled out, and the auxiliary roller only circulates when the paper is pulled out, so that the pulling force of the paper at the platen can be reduced, It is possible to prevent wear and deterioration of the paper feed roller and reduction of the friction coefficient due to paper dust.

[Brief description of drawings]

FIG. 1 is a perspective view showing an entire automatic sheet feeder according to an embodiment of the present invention. FIG. 2 is a sectional view showing a main part of the automatic paper feeder. FIG. 3 is a sectional view taken along the line II-II in FIG. FIG. 4 is a flowchart of the automatic paper feeder. FIG. 5 is a cross-sectional view showing a process after the end of paper discharge of the automatic paper feeder. FIG. 6 is a sectional view showing a state of the automatic paper feeder after the reverse rotation process is completed. FIG. 7 is a sectional view showing a state of a sheet feeding process of the automatic sheet feeder. FIG. 8 is a sectional view showing a state of the aligning process of the automatic paper feeder. FIG. 9 is a sectional view showing a state of a printing process of the automatic paper feeder. FIG. 10 is an explanatory plan view showing the relationship between the clutch disc and the ratchet pawl shown in FIG. 1 in the process after the completion of paper discharge. FIG. 11 is a sectional view taken along the line III-III in FIG. FIG. 12 is a sectional view taken along line IV-IV in FIG. FIG. 13 is an explanatory plan view showing the relationship between the clutch disc and the ratchet pawl of FIG. 1 in the reverse rotation process. FIG. 14 is a sectional view taken along line VV of FIG. FIG. 15 is a sectional view taken along the line VI-VI in FIG. FIG. 16 is a sectional view taken along the line VII-VII in FIG. FIG. 17 is an explanatory plan view showing the relationship between the clutch disc and the ratchet pawl of FIG. 1 in the paper feeding process. FIG. 18 is a sectional view taken along line VIII-VIII in FIG. FIG. 19 is a sectional view taken along the line IX-IX in FIG. FIG. 20 is a sectional view taken along the line XX of FIG. FIG. 21 is a sectional view taken along the line XI-XI in FIG. [Explanation of symbols of main parts] 1 ... Automatic paper feeder 2 ... Printer 3 ... Hopper 6 ... Feeding roller shaft 7 ... Feeding roller 8 ... Pressure plate 10 ... Platen 16 ... Auxiliary Roller arm 16A: Auxiliary roller C: Clutch device.

Claims (1)

[Claims] 1. A paper feed roller which is detachably attached to a printer and which is connected to a drive shaft of the printer via a paper feed roller shaft and rotates in synchronization with forward and reverse rotations of the drive shaft of the printer. It is equipped with a hopper that has a pressure plate that presses and urges the paper rollers, and in an automatic paper feeder that separates the sheets stacked on the hopper one by one from the top and feeds them sequentially to the printer Of the auxiliary roller arm, an auxiliary roller that is pivotally supported by the auxiliary roller arm and comes into contact with the paper, a clutch disc that is integrally attached to the auxiliary roller arm and is rotatably attached to the paper feeding roller shaft, and Installed between the side plate of the clutch disc and the side plate of the hopper, and the ratchet pawl that is pressed against the outer peripheral surface of the clutch disc. The one-way clutch has an operating rod at one end that is locked by the paper feed roller when the paper feed roller rotates in reverse and is unlocked by the paper feed roller when the paper feed roller rotates normally. , An arm stopper that blocks the rotation of the auxiliary roller arm within the rotation trajectory of the auxiliary roller arm, and a partition wall extending in the circumferential direction is formed on the outer peripheral surface of the clutch disc, and ratchets are provided on both sides of the partition wall. A clutch-on pawl guide passage that locks the tip of the pawl when the paper feed roller rotates forward and a clutch-off pawl guide passage that bypasses the ratchet pawl are formed.At one end of the partition wall, the ratchet pawl is connected to the clutch-on pawl guide. A guide surface that guides the passage is formed, and a guide surface that guides the ratchet pawl to the clutch-off pawl guide passage is formed at the other end. A reverse rotation preventing stopper for preventing reverse rotation of the operating rod of the directional clutch hopper in the reverse rotation direction and a forward rotation preventing stopper for preventing forward rotation of the operating rod of the one-way clutch in the forward rotation direction are provided. And automatic paper feeder.