JPH072371A - Paper feed mechanism for printer - Google Patents

Abstract

PURPOSE:To provide a completely automated paper feed mechanism reducing the size of a printer main body and requiring no manual action by coaxially providing a cam shaft and a roller shaft on the automatic paper feed mechanism of a printer. CONSTITUTION:This printer fitted with an automatic paper feed mechanism of slips 3 in a printer main body is provided with a pair of the right and left cams 6 opening or closing a pressure plate 4 pressing the slips to a separation roller 1, a cam shaft connecting a pair of the right and left cams 6, and the separation roller 1 provided coaxially with the cam shaft.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feed mechanism of a printer.

[0002]

2. Description of the Related Art As shown in FIG. 3, a sheet feeding mechanism used for a conventional cut sheet has a separating roller 1, a motor (not shown) for driving the separating roller, and a rotation shaft of the separating roller 1 that serves as a motor. Roller shaft 2 that transmits the driving force of
Is pressed against the separating roller 1 by using the shaft 10 as a fulcrum, a spring 5 is applied to press the pressure plate 4, and the pressure plate 4 opens and closes the cut sheet 3 so as to press the cut sheet 3 in the roller shaft direction. A pair of left and right cams 6, a cam shaft 7 that interlocks the pair of left and right cams 6, a lever 8 that is manually movable in the a direction integrally with the cams 6, and a single-cut sheet 3 sent by the separation roller 1 one by one And a separation plate 9 that is peeled off.

Next, in the operation of this paper feed mechanism, the operator moves the lever 8 in the direction of arrow a with a plurality of cut sheets 3 set on the pressure plate 4. Lever 8 is cam 6
Since the pair of left and right cams 6 are fixed by the cam shaft 7, the pressure plate 4 is lifted in the direction of arrow b by the spring 5 about the shaft 10 as a rotation center and pressed against the separation roller 1. . Next, the roller shaft 2 is rotated by a motor in the direction of arrow c. The separation roller 1 sends the cut sheet 3 in the direction of arrow e. At this time, the plurality of sheets are separated one by one by the separation plate 9 and passed through the guide plates 30A and 30B.
And is guided to the printing unit 32.

[0004]

In the conventional paper feeding mechanism of the printer, a cam shaft for connecting the left and right cams for opening and closing the pressure plate and a lever for the operator to operate must be mounted. In addition to the difficulty of designing these mechanisms, there is a drawback that the size of the printer main body is increased. Further, since the operator operates the lever every time the cut sheet is set, there is a drawback that it is difficult to use due to this manual operation process.

[0005]

SUMMARY OF THE INVENTION In a paper feeding mechanism of a printer of the present invention, there are provided a pressure plate for mounting cut sheets, a separation roller rotated about an axis by a motor, and a press sheet for pressing the cut sheets against the separation roller. In a paper feeding mechanism of a printer having a pair of left and right cams for opening and closing the pressure plate, a shaft of the separation roller and a cam shaft which is the shaft of the cam are arranged coaxially, and the shaft of the separation roller has a pipe structure. And
The camshaft is provided so as to be rotatably inscribed in the pipe structure.

[0006]

The present invention will be described below with reference to the drawings. 1 is a cross-sectional view of an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the periphery of the embodiment of FIG. 1 and 2, the same reference numerals as those in FIG. 3 of the conventional example have the same functions. That is, FIG. 1 and FIG.
In the embodiment of FIG. 3, the roller shaft 2 and the cam shaft 7 are arranged at different positions in the conventional example of FIG. 3, whereas the shaft of the separation roller 1 is a roller structure having a roller pipe 19.
The camshaft 2 is installed coaxially with the roller pipe to reduce the size.

When the automatic paper feed mechanism is used as the initial operation of this embodiment, the sheet guide 11 is opened in the direction of the arrow f, and a plurality of cut sheets 3 are fed to the sheet guide 11 and the pressure plate 4.
Place it on top and pass it between the separation roller 1 and the pressure plate 4,
Place the tip against the separation plate 9. In a normal stationary state of the automatic paper feeding mechanism, the pressure plate 4 is lowered by the cam 6 as shown in the i direction, and the separation roller 1 and the pressure plate 4 are separated from each other.

Next, the movement when a print command is received on the cut-sheet paper 3 is such that the motor 12 is first rotated and the cam gear 15 and the roller gear 16 shown in FIG. It is rotated in the direction of arrow g indicated by. Since the one-way clutch 17 is incorporated in the cam gear 15 and the one-way clutch 18 is incorporated in the roller gear 16, the one-way clutch 17 locks when the one-way clutch 17 rotates together with the cam gear 15 in the direction of the arrow g to apply power to the camshaft 2. introduce. Further, the one-way clutch 18 and the roller gear 16 are adapted to be locked when rotating in the direction of the arrow g to transmit power to the roller pipe 19 to which the separation roller 1 is fixed. Since the cam gear 15 is rotating in the arrow g direction, the rotation is transmitted from the cam shaft 2 to the left and right cams 6, and the cam 6 also starts rotating in the arrow g direction. Due to the rotation of the cam 6, the pressure plate 4 pressed by the spring 5 gradually moves in the direction of arrow b due to the phase shift of the cam 6, and finally the pressure plate 4 is completely separated from the cam 6 and the separation roller 1 Can be pressed against. At this time, the switch of the micro switch 20 is turned off, and the motor 1
Since the current to 2 is cut off, the motor 12 stops rotating. In this state, the cut sheet 3 is the pressure spring 5
The pressure plate 4 presses the separating roller 1 by the amount of the pressure.

Next, the motor 12 is rotated in the reverse direction, and the cam gear 15
And the roller gear 16 are rotated in the direction of arrow h, but the one-way clutch 17 of the cam gear 15 idles, the cam shaft 7 does not rotate, and the one-way clutch 18 of the roller gear 16 is in the locking direction.
The rotation is transmitted to 9, and the separation roller 1 fixed to the roller pipe 19 starts to rotate. Cut sheet 3 is separation roller 1
Is moved in the direction of arrow e due to friction with and is applied to the separating plate 9, and then separated into one sheet, and is fed until it is caught at the contact point between the feed roller 21 and the pressure roller 22. The feed amount of the cut sheet 3 is determined by the number of steps of the motor 12, and is controlled so as to stop when a certain number of steps is rotated. After feeding the single-cut sheet 3, the motor 12
Reversely rotates again and rotates the cam gear 15 and the roller gear 16 in the direction of arrow g, but the one-way clutch 18 of the roller gear 16 idles, so that the separation roller 1 does not rotate and the one-way clutch 17 of the cam gear 15 is in the locking direction. Therefore, the rotation is transmitted to the cam shaft 7, the cam 6 starts to move, and the pressure plate 4 is moved in the direction of arrow i. The stop position of the cam 6 is the position where the pressure plate 4 is farthest from the separation roller 1, and this position is the position where the motor 12 is moved by a certain number of steps from the time when the micro switch 20 for detecting the position of the pressure plate 4 is turned on. It is the moved position. Now the pressure plate 4
Position returns to the normal rest state, and the motor 12 stops. The cut sheet 3 is sent from the feed roller 21 to the platen 31 and printed by the printing unit 32.

[0010]

As described above, according to the present invention, since the cam shaft connecting the pair of left and right cams and the roller shaft of the separation roller are provided coaxially, the size of the printer main body can be reduced. Further, by using the same motor as the drive source of the separation roller as the drive source of the pressure plate, there is an effect that the operator does not need to operate the lever.

[Brief description of drawings]

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

FIG. 2 is a sectional view of a peripheral portion of the separation roller shown in FIG.

FIG. 3 is a sectional view of an automatic paper feeding mechanism of a conventional printer.

[Explanation of symbols]

 1 Separation Roller 2 Roller Shaft 3 Single Sheet Paper 4 Pressure Plate 5 Spring 6 Cam 7 Cam Shaft 9 Separation Plate 10 Shaft 11 Sheet Guide 12 Motor 13 Reduction Gear 14 Idle Gear 15 Cam Gear 16 Roller Gear 17, 18 One Way Clutch 19 Roller Pipe

Claims (2)

[Claims] 1. A pressure plate on which cut sheets are mounted, a separation roller that rotates about an axis by a motor, and a pair of left and right cams that open and close the pressure plates to press the cut sheets against the separation rollers. In the paper feeding mechanism of the printer,
A shaft of the separation roller and a cam shaft that is the shaft of the cam are arranged coaxially, and the shaft of the separation roller has a pipe structure, and the cam shaft is rotatably inscribed in the pipe structure. A paper feeding mechanism of a printer, which is characterized in that 2. A roller gear that meshes with a drive gear that transmits the drive of the motor and transmits a driving force to the shaft of the separation roller, and a cam gear that meshes with the drive gear and transmits the driving force to the cam shaft. 2. The paper feed mechanism for a printer according to claim 1, wherein the roller gear and the cam gear rotate independently of each other by controlling a one-way clutch provided in each of the cam gear and the cam gear.