JPH0423014Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a paper feeding mechanism in a printing device such as a printer or typewriter, which is provided with a pressure roller that follows the movement of a platen, and which feeds paper by the roller.

Prior art In order to improve printing quality in printing devices,
The relative position of the platen and print head must be precisely determined. Therefore, there are conventional printers that allow the position of the platen to be finely adjusted with respect to the print head.

On the other hand, in the printing device, a pressure roller is pressed against the platen in order to feed paper.

Therefore, even if you slightly adjust the position of the platen,
The pressure roller must be configured to follow it.

However, although conventional devices can follow the parallel movement of the platen, they cannot follow the direction in which the platen is tilted.

For this reason, there is a difference in the pressing force of each pressure roller against the platen, which may impede paper feeding and cause skew or the like.

Purpose The purpose of this invention is to eliminate the above-mentioned drawbacks of conventional printing devices.The pressure roller follows the delicate movement of the platen,
The object is to be able to reliably follow both the parallel movement of the platen and the movement of the platen in the direction of inclination.

Configuration Next, this invention will be explained based on an embodiment shown in the drawings.

1 and 2 show the paper feeding mechanism according to the invention in the paper feeding state, and FIG. 3 shows the paper feeding mechanism in the paper setting state. Figure 4 is the first
FIG. 5 is a view taken in the direction of arrow A in FIG. 1, and FIG. 5 is a view taken in the direction of arrow B in FIG. 1, showing a rotating shaft and a pressure roller bracket attached to the rotating shaft with a stepped screw.

In the figure, a platen shaft 2 and a rotation shaft 3 are horizontally suspended parallel to each other between a right side plate 1 and a left side plate (not shown), and a platen 4 having the platen shaft 2
In order to adjust the relative position with the printing head (not shown), the
It can be adjusted moving in the direction. Further, a guide plate 5 is fixed to the rotating shaft 3 by screws 6, and is formed to extend in an arc shape along the lower outer periphery of the platen 4 and cover it from the outside. This guide plate 5 is provided with a pressure roller 14, which will be described later.
There are four openings 5a for viewing. Further, near the center of the rotation shaft 3, a U-shaped bracket 7 is attached with a stepped screw 8 so as to be swingable about a support shaft orthogonal to the rotation shaft 3. Furthermore, a pivot shaft 9 is spanned between the ends of both side plates of this U-shaped bracket 7 in parallel with the platen 4, and a pivot shaft 9 is attached to both ends of the pivot shaft 9 along the outer periphery of the platen so as to face the inner surfaces of both side plates of the bracket 7. Roller holding plates 10 extending in an arc shape are rotatably supported around respective pivot shafts 9. Between these two roller holding plates 10, 10, there are two roller shafts 11, 1 parallel to the platen 4.
2 is passed over. Those roller shafts 11, 12
have two pressure rollers 13 and 1, respectively.
3, 14, 14 are attached, and the roller shaft 11,
It is possible to rotate around 12. These pressure rollers face the aforementioned guide plate opening 5a and press the platen 4.

Therefore, the guide plate 5 and bracket 7 attached to the rotating shaft 3 move in the direction of arrow A in FIG. 2 as the rotating shaft 3 rotates counterclockwise in FIGS. 1 and 2. As shown in FIG. 3, the sheet is placed in the paper setting position facing away from the platen 4 at a slightly larger distance. As shown in FIG. 2, the paper feed position is opposite to the outer periphery of the platen with a small distance therebetween. Further, the bracket 7, which is pivotally supported on the rotating shaft 3 by a support shaft orthogonal thereto, swings in directions C and D in FIG. Since the roller holding plates 10, 10, which are supported by the penetrating pivot 9, rotate around the pivot 9 in the directions E and F in FIGS. 2 and 3, the roller holding plates 1
Pressure roller 13,1 held at 0,10
3, 14, 14 can move in any direction. Therefore, even if the platen position is moved by adjusting the position of the platen relative to the print head, or even if there is an installation error between the rotary shaft and the platen, the pressure roller will remain completely intact over its entire range of movement. Can touch the platen.

Further, notches 7a are formed in the upper end surfaces of both side plates of the bracket 7 at the portions where the roller shafts 11 come into contact with each other, so that the roller holding plate 10 is centered around the pivot shaft 9 when the paper is set as shown in FIG. When rotated in the direction of the arrow, both ends of the roller shaft 11 engage with this notch 7a, and the pressure roller 13
and the platen 4 can be made approximately equal.

Next, a mechanism for rotating the rotation shaft 3 will be explained.

An L-shaped release lever 16 is connected to the outside of the right side plate 1 via a pin shaft 15 provided on the right side plate 1.
is installed. The upper end of this lever 16 protrudes outside the printer body and has an operating knob 17 at the tip. The other end has a U-shaped locking portion 16a.
is formed. A toggle spring 18 having both ends fixed to the locking portion 16a and the right side plate 1 is applied. Therefore, when the knob 17 is operated, the locking portion 16a of the lever moves using the pin shaft 15 as a fulcrum, and the locking force of the toggle spring 18 moves the release lever 16 to the paper feed position (FIGS. 1 and 2) or to the paper set position ( (Fig. 3). Also, this release lever 16
Two arm members 19 and 20 are provided in order to transmit the movement to the rotation shaft 3 and rotate the rotation shaft 3. That is, one arm member 19 is inverted L.
It is formed in a letter shape, one end 19a of which is engaged with the end of the rotating shaft 3 having a rectangular cross section, and a pin 21 is provided at the other end. The release lever 16 has a pin shaft 1
5, an arm portion 22 is extended in the opposite direction to the knob 17, and a pin 23 at the end of the arm portion is provided. This pin 23 and the pin 21 of the arm member 19 are fitted into holes at both ends of the intermediate arm member 20 to connect them. pin 2
The hole in the arm member 20 that engages with the lever 16 is formed into an elongated hole that is larger than the diameter of the pin 23 by the distance b, and the force of the toggle spring 18 is applied to the lever 16 and the arm members 20 and 1.
9 does not increase the pressing force of the pressure rollers 13 and 14 against the platen 4. A spring 24 is also provided between the upper end 19a of the arm member 19 and the lower part of the right side plate 1.
is applied to determine the pressing force of the pressure rollers 13, 13, 14, 14 against the platen 4, and by this pressing force, when the platen 4 is driven, the pressure rollers 13, 13, 14, 14 are driven to convey the paper. can be done. In addition,
A similar mechanism is provided on the left side plate (not shown), and a spring is applied to it.

To use the paper feeding mechanism according to the present invention constructed as described above, first pull the release lever knob 17 from the position shown in FIG. 1 in the direction of arrow G.
Then, the release lever 16 rotates about the pin shaft 15, and the rotation shaft 3 is rotated counterclockwise in FIGS. 1 and 2 via the arm members 20 and 19 connected to the lever 16. move, third
The state shown in the figure will be reached. In the example, the knob is 12
At this time, the rotation shaft rotates 5 degrees, and the guide plate 5 and bracket 7, which are locked to the rotation shaft 3, rotate by that angle in the direction shown in the figure, about the rotation shaft 3, and move away from the platen 4. Leave (see Figure 3). At the same time, pressure rollers 13, 13, 14, 1 supported on the bracket 7 via the pivot 9 and the roller holding plate 10
4 also leaves the platen 4. Then, the pressure rollers 13, 13, 14, 14 are connected to the roller shaft 11,
The bracket 7 attached through the bracket 12 is always given the tendency to rotate in the direction shown in FIG. At this time, since the notch 7a is provided at the position of the bracket 7 where one of the roller shafts 11 contacts, the roller shafts 11 of the pressure rollers 13, 13
Both ends of the platen 4 and the pressure rollers 13, 13, 14, 14 move by the distance a between the shaft tip and the notch 7a plus the amount of movement due to the rotation of the bracket 7 about the rotation shaft 3. Intervals c and d are formed between them. This paper set state depends on the positional relationship between the locking portion 16a and the toggle spring 18, and the force of the toggle spring 18 is transferred to the spring 2.
Since it overcomes the power of 4, it will be maintained as it is. Therefore, in this paper feeding state, the platen 4
Since an appropriate distance is maintained between the press rollers 13, 13, 14, 14, the platen 4, and the guide plate 5, the paper can be set in the E direction, the set paper position can be corrected, or the paper can be moved. It is easy to remove and remove it smoothly.

To enter the paper feeding state, tilt the knob 17 in the direction of arrow C shown in FIG.
The positional relationship between a and the toggle spring 18 changes as shown in FIG. 2, and as the rotation shaft 3 rotates, the guide plate 5
and pressure rollers 13, 13, 14, 14
The press rollers 13, 13, 14, and 14 press the set paper against the platen 4 while maintaining complete contact with the platen 4. At this time, since a gap is formed between the pin 23 of the lever 16 and the long hole of the arm member 20, the force of the toggle spring 18 does not act on the pressing force of the pressure roller.

Effects According to this invention, when the pressure roller is pressed against the platen during paper feeding, even if there is some installation error between the platen and the pressure roller support member, the position of the platen relative to the print head can be adjusted. However, the pressure roller can follow the movement of the platen, and can reliably follow both the parallel movement of the platen and the movement of the platen in the tilt direction over the entire movement range of the pressure roller. Therefore, since each pressure roller is evenly pressed against the platen, it is possible to eliminate the risk of problems such as skew due to poor paper feeding.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a paper feeding mechanism which is an embodiment of this invention, Fig. 2 is an explanatory diagram of the paper feeding state of the paper feeding mechanism, Fig. 3 is an explanatory diagram of the paper set state, and Fig. 4 is an explanatory diagram of the paper feeding state of the paper feeding mechanism. FIG. 5 is a view taken in the direction B of FIG. 1, and shows the rotating shaft and the bracket attached to it with a stepped screw. 3... Rotating shaft, 4... Platen, 7... Bracket (supporting member), 9... Pivot, 10... Roller holding plate, 11, 12... Roller shaft, 13, 14...
…Pretsia Laura.

Claims (1)

[Claims for Utility Model Registration] A rotating shaft that is provided parallel to the platen and rotates by external operation, and a pivot that is attached to the rotating shaft so as to be swingable about a support shaft perpendicular to the rotating shaft to adjust the inclination angle with respect to the platen. a support member that rotates as the rotation shaft rotates; and a pivot that is supported substantially parallel to the platen by the support member and moves toward or away from the platen as the support member rotates. and two roller shafts are supported rotatably around the pivot shaft, and two roller shafts are spanned approximately parallel to the platen, and a pressure roller is held via these roller shafts, and the pressure roller is mounted on the supporting member. A paper feed mechanism for a printing device, consisting of a roller holding plate that presses against or pulls away from the platen as it rotates.