JPH0687245A - Paper feed device - Google Patents

Abstract

PURPOSE:To prevent locking of an idle gear and stepping-out in a platen driving motor during paper feeding action or reverse line feed printing in a paper feed device in a printer, etc. CONSTITUTION:A first idle gear A1a is engaged with a platen gear 10 of a platen 17, and a first idle gear B1b is fixed on the same shaft as the gear A1a through a slip clutch. The gear B1b is engaged with a second idle gear B2b, a planetary gear, and a third idle gear 3 which is fixed on the same shaft as the fourth gear 4. The gear 4 is engaged with a pick roller gear 6 fixed on a pick roller shaft 13 which feeds a sheet 18 through the fifth idle gear 5. The gears 3, 4 having a tooth-defective part control power transmission corresponding to the rotational positions of the gears. When the gear 3 is nearly locked during the reverse rotation of the platen 17, the slip clutch slips to prevent the in the driving motor of the platen 17. In this way, reverse line-feed printing can be carried out without limit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeding device used for a printing device or the like, and more particularly to a paper feeding mechanism therefor.

[0002]

2. Description of the Related Art Conventionally, a sheet feeding apparatus of this type has an idle gear train including a planetary gear and a toothless gear that directly receive power from a platen gear of a printing apparatus, so that a reverse rotation of the platen can be used as a pulling stroke. It was a paper feed mechanism that sucked the paper by transmitting a positive rotation to the pick roller connected to the tip of the gear by a fixed amount.

[0003]

In the above-described sheet feeder of the sheet feeder, since the reverse rotation of the platen gear is pulled during the sheet feeding operation, the sheet feeding operation and the reverse line feed printing are performed. When the platen is rotated in the reverse direction, the first idle gear and the second idle gear mesh with the third idle gear, and the first idle gear and the second idle gear respectively transmit rotations in opposite directions to the third idle gear. Because I try to do so, the first idle gear locks up and I can't go back to the line. In addition, since the first idle gear is locked, the platen drive motor of the printing apparatus may be out of step, which may affect the life and quality of the drive motor.

[0004]

A sheet feeding device of the present invention has a main gear that engages with a platen gear fixed to a platen shaft and a main gear that is provided coaxially with the main gear and that has a predetermined direction in a predetermined direction with respect to rotational power of the main gear. A first idle gear, which is an auxiliary gear that is connected by a slip clutch that stops the transmission of power when a load greater than a certain value is applied, and a planetary gear that is connected by a link around a spindle of the first idle gear. There is a second
Idle gear, a third idle gear engaged with the auxiliary gear of the first idle gear, a fourth idle gear fixed coaxially with the third idle gear, and a fourth idle gear
A fifth idle gear that engages with the idle gear, and a pick roller gear that engages with the fifth idle gear and that is coaxial with a pick roller that sends out a sheet, and further comprises: After the fourth idle gear and the fifth idle gear are disengaged from the tooth surfaces of the idle gear and the fourth idle gear, the third idle gear and the third idle gear are separated from each other. Notch portions facing each other are provided so that meshing of the idle gear No. 1 with the sub gear is separated.

[0005]

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

FIG. 1 is a perspective view showing an embodiment of the present invention. The first idle gear A1a arranged to engage the platen gear 10 fixed to the shaft of the platen 17 and the coaxial first idle gear B1b are connected by a slip clutch, and the first idle gear A1a and the first idle gear A1a 1
Link 11 that rotates around the main shaft of idle gear B1b
A second idle gear A2a and a second idle gear B2b are provided coaxially with the second idle gears A and B so that the second idle gears A and B rotate around the first idle gears A and B as planetary gears. It constitutes the oscillating gear. FIG. 2 is a sectional view of this swing gear. First idle gear A
1a and the first idle gear B1b are provided with recesses on their side surfaces facing each other, and a slip clutch 12 is provided across the recesses.

Third idle gear 3 and fourth idle gear 4
Form a two-stage gear fixed coaxially and are engaged with the fifth idle gear 5. 5th Idol Gear 5
Is engaged with a pick roller gear 6 provided coaxially (pick roller shuff 13) for sending out the paper 18. The structure of this two-stage gear is shown in FIG. 3, where (a) is a longitudinal sectional view and (b) is a side view. The third idle gear 3 of the two-stage gear is engaged with the first idle gear B1b, and the fourth idle gear 4 is engaged with the fifth idle gear 5. The notch 3c is formed in a part of the tooth surface of each of the third idle gear 3 and the fourth idle gear 4,
4c is provided, and the position of the notch is managed so that the third idle gear 3 and the first idle gear B1b are disengaged after the fourth idle gear 4 and the fifth idle gear 5 are disengaged. .

Further, the second idle gear B2b is engaged with the third idle gear 3 to transmit the rotation to the third idle gear 3, and the third idle gear 3, the second idle gear B2b and the first idle gear B1b are engaged. After combining, the first idle gear B1
When the transmission torque of the platen gear 10 on b exceeds a certain value, the slip clutch 12 slips and the first idle gear B1b is not transmitted even if engaged.

Next, the operation of the present invention will be described.

As a condition of the initial state, as shown in FIG. 4, the first idle gear A1a and the third idle gear 3 are in positions where power is not transmitted by the notch 3c of the third idle gear 3. In this initial state, the platen gear 10
Can be easily reached by positive rotation (in the direction of arrow F) over a certain amount. That is, when the platen gear 10 rotates in the forward direction, the first idle gear B1b engaging with the platen gear 10 rotates, and the rotation is transmitted to the third idle gear 3. However, when the cutout portion 3c of the third idle gear 3 faces the first idle gear, the power transmission is stopped and only the first idle gear B1b rotates. A part of the fourth idle gear engaged with the fifth idle gear 5 is cut out (4 in the figure).
The reason (c) is to prevent the third idle gear 3 from continuously engaging with the first idle gear B1b due to the reaction force of the pick roller 14.

Now, when the sheet feeding operation is started, the platen gear 1
0 rotates in the reverse direction (arrow R direction), and the first idle gear A1a
And B1b and the second idle gears A2a and B2b move to a position where the second idle gear B2b of the swing gear engages with the third idle gear 3 (see FIG. 5), and when the reverse rotation is continued, 3 The idle gear 3 moves to a position where it engages with the first idle gear B1b (see FIG. 6).

Next, when the rotation of the platen gear 10 is changed to the forward rotation in the F direction, the second idle gears A2a and B2b engaged with the third idle gear 3 are ejected coaxially with the paper discharge roller. When the platen gear 10 is moved to a position where it engages with the roller gear 7 and continues to rotate forward,
Is transmitted to the eject roller gear 7. The eject roller gear 7 rotates the eject roller 15 and the second eject roller 16 via the idle gear 8 and the second eject roller gear 9 to convey the paper 18. Further, the first idle gear B1b and the third idle gear 3 are engaged with each other and rotate, so that the fourth idle gear 4 and the fifth idle gear 5 are engaged with each other and the sheet 1 is conveyed through the fifth idle gear 5.
The power is transmitted to the pick roller gear 6 provided coaxially with the pick roller 14 which sends out 8 to send a fixed amount, and the gear train returns to the initial state again.

Further, as shown in FIG. 6, the second idle gears A2a and B2b, which are swing gears, and the third idle gear are continuously rotated in the reverse direction.
The idle gear 3 and the first idle gear B1b are engaged,
The slip clutch 1 that connects the first idle gear A1a and the first idle gear B1b even when the first idle gear B1b is continuously rotated in the reverse direction and a certain load is applied to the first idle gear B1b.
The second idle slips the first idle gear A1a.
Only the first idle gear B1b does not rotate. Therefore, even if the first idle gear B1b and the second idle gear B2b transmit power to the third idle gear 3 in opposite directions, the first idle gear A1a can perform the reverse line feed operation without being locked.

As described above, after the platen gear is normally rotated by the paper discharge operation, the gears are engaged by the reverse rotation by the paper suction operation, and then the platen gear is returned to the normal rotation. The paper is delivered from the roller to the rear of the platen, and further forwardly rotated, so that the paper is ejected from the paper feeding device. Further, even if the reverse line feed is printed on the paper being printed, the gear is not locked, so that the reverse line feed can be executed without any limitation.

[0015]

As described above, according to the present invention, by having the idle gear train including the planetary gear, the toothless gear, and the gear having the slip clutch built therein, the positive rotation of the platen gear is transmitted to the pick roller by a constant rotation. The paper can be sucked in, reverse printing can be performed indefinitely, the mechanical unit can be downsized without stepping out the drive motor, and the reliability of the apparatus can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing a configuration of first and second idle gears of the embodiment of FIG.

3 (a) is a vertical cross-sectional view showing a configuration of third and fourth idle gears of the embodiment of FIG. 1, and FIG. 3 (b) is a side view thereof.

FIG. 4 is a diagram showing an initial state of the embodiment of FIG.

5 is a diagram showing a reverse rotation start state for the suction operation of the embodiment of FIG.

FIG. 6 is a diagram showing a state where the reverse rotation of the suction operation of FIG. 5 is completed.

[Explanation of symbols]

 1a 1st idle gear A 1b 1st idle gear B 2a 2nd idle gear A 2b 2nd idle gear B 3 3rd idle gear 4 4th idle gear 5 5th idle gear 6 pick roller gear 7 eject roller gear 8 idle gear 9 Second eject roller gear 10 Platen gear 11 Link 12 Slip clutch 13 Pick roller shaft 14 Pick roller 15 Eject roller 16 Second eject roller 17 Platen 18 Paper

Claims (1)

[Claims] 1. A main gear that engages with a platen gear fixed to a platen shaft, and a transmission of the power is stopped when a load of a predetermined value or more is applied in a predetermined direction to the rotational power of the main gear that is provided coaxially with the main gear. A first idle gear that is a sub gear that is connected by a slip clutch, a second idle gear that is a planetary gear that is connected by a link around a support shaft of the first idle gear, and the first idle gear. A third idle gear that engages with the auxiliary gear of the idle gear, a fourth idle gear that is fixed coaxially with the third idle gear, and a fifth idle gear that engages with the fourth idle gear. And a pick roller gear that is coaxial with a pick roller that engages with the fifth idle gear and sends out a sheet, and further includes the third idle gear and the fourth idle gear. For a part of each tooth surface with the gear,
The notches facing each other so that the fourth idle gear and the fifth idle gear are disengaged from each other and the third idle gear and the first idle gear are disengaged from each other. A sheet feeding device characterized by being provided.