JPH07290787A - Serial printer - Google Patents

Abstract

PURPOSE:To simplify mechanism and reduce the manufacturing cost by a method wherein a spring member of a partial roller is possessed jointly to the spring member of the other roller when the roller is shunted from a form running path by leaving a part of the roller behind. CONSTITUTION:In the case where continuous form 16 is inserted through the front, the continuous form 16 passes through a gap between a paper guide 6 and form guide 13 and a gap between a platen 2 and a printing head 1 and is run by a tractor feeder 18. Then in the case where the form is inserted through the rear, the continuous form 15 is sent to the printing head 1 by passing through the gap between the paper guide 6 and platen 2. Since a lever 5 is changed in the direction of an arrow A, it performs printing action of the continuous form. When the lever 5 is turned in the direction of the arrow 5, a shaft 8 fitted to a stay 7 is turned, a bracket 9 fitted to the shaft 8 is turned downward and a press spring 11 is compressed. A roller support 4 is moved downward through a shaft 21 of the bracket 9 and a press roller 3-b is shunted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a serial printer, and more particularly to a serial printer capable of running paper from the front or the rear.

[0002]

2. Description of the Related Art FIG. 4 is a side view showing an example of a conventional serial printer. Referring to FIG. 4, continuous paper 16
When the paper is inserted from the front, the continuous paper 16 is sent to the platen 2 and the print head 1 through the gap between the paper guide 6 and the paper guide 13 by the tractor feeder 18. Also,
When the paper is inserted from the rear side, the continuous paper 15 is sent to the print head 1 through the gap between the paper guide 6 and the platen 2 by the tractor feeder 17. At this time, the continuous paper printing operation is performed by switching the lever 5 in the direction of arrow A. When the lever 5 is rotated in the direction of arrow A, the stay 7
The shaft 8 attached to the shaft 8 rotates, and the bracket 9 attached to the shaft 8 rotates downward to compress the pressure spring 11. By the movement of the bracket 9, the front roller support 12 engaging with the stay 7 via the pressure spring 20 is pushed down around the shaft 22, and the pressure roller 3-c retracts from the feed roller 14. Further, the roller support 4 engaging with the bracket 9 via the shaft 21 simultaneously moves downward, and the platen 2
Then, the pressure roller 3-b is retracted. Spring 19
Is fixed to the bracket 9 and the other is lightly pressed against the roller support 4, so that the pressure roller 3-a presses the platen 2 with a very weak pressure to stably run the continuous paper 15.

[0003]

In this conventional serial printer, since a plurality of pressure rollers are provided with pressure springs respectively, the mechanism is complicated and the manufacturing cost is high.

[0004]

SUMMARY OF THE INVENTION A serial printer according to the present invention has a plurality of rollers for feeding a sheet which travels along a traveling path set between a print head and a platen, which are arranged to face the platen. In the printer, when some of the rollers are left and retracted from the paper path, some of the spring members of the rollers are shared with the spring members of the other rollers.

Further, the serial printer of the present invention includes a first support member for holding a plurality of rollers for inserting a sheet from the rear of the platen and holding the sheet together with the platen for traveling, and from the lower side of the platen, A second support member that holds a driving roller of a pair of rollers that inserts a paper sheet and holds the paper sheet, and a second support member that rotatably supports the first support member. A third support member that rotates via a first spring member and that rotates in conjunction with a lever that switches between running of cut sheets and continuous paper; the first support member, and the second support member. Second spring member that engages with the platen to retract a part of the plurality of rollers from the platen and presses the other part of the plurality of rollers with the platen with a very weak pressure to stably run the continuous paper. With.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a side view of a serial printer according to an embodiment of the present invention when traveling on cut sheets, FIG. 2 is a side view showing a state in which continuous paper is traveling with a tractor feeder of this serial printer, and FIG. It is a front view of the pressure roller part which removed the platen of this serial printer.

Referring to FIG. 1, the case of traveling a cut sheet will be described. The lever 5 is rotatably fixed to a shaft 8 attached to a stay 7. Pressure rollers 3-a and 3-b are rotatably attached to a roller support 4 that engages with a bracket 9 attached to a shaft 8 via a shaft 21. The pressure rollers 3-a and 3-b are pressed against the platen 2 by a pressure spring 11 provided between the bracket 9 and the stay 7, so that the single-cut sheet is inserted from the rear side of the platen 2 to run.
The front roller support 12 rotatably attached to the stay 7 via a shaft 22 applies a pressure roller 3-c by a pressure spring 10 provided so as to connect the roller support 4 and the front roller support 12. The pressure roller 3-c presses the feed roller 14 against the pressure roller 3-c so that the single-cut sheet is inserted from the front side to run.

Next, referring to FIG. 2, the operation of running the continuous paper of this embodiment will be described. When the continuous paper 16 is inserted from the front side, the continuous paper 16 is run by the tractor feeder 18 through the gap between the paper guide 6 and the paper guide 13 and the gap between the platen 2 and the print head 1. When the paper is inserted from the rear side, the continuous paper 15 is sent to the print head 1 through the gap between the paper guide 6 and the platen 2 by the tractor feeder 17. The lever 5 is switched in the direction of arrow A to perform continuous paper printing operation. When the lever 5 is rotated in the direction of arrow A, the shaft 8 attached to the stay 7 is rotated, and the bracket 9 attached to the shaft 8 is rotated downward,
The pressure spring 11 compresses. Shaft 21 on bracket 9
At the same time, the roller support 4 that is engaged via the roller support 4 moves downward, and the pressure roller 3-b retracts from the platen 2. Further, the front roller support 12 is also pushed down around the shaft 22 by the movement of the bracket 9, and the pressure roller 3-c retracts from the feed roller 14. Here, since the roller support 4 and the front roller support 12 are connected by the pressure spring 10, the pressure roller 3-b side of the roller support 4 is retracted from the platen 2. At this time, the pressure spring 10 has a spring length closer to a free length than when the pressure roller 3-c is in pressure contact with the feed roller 14, and the pressure roller 3-a is in pressure contact with the platen 2 with a very weak pressure. The continuous paper 15 can be stably run.

[0009]

As described above, according to the present invention,
It has a plurality of rollers for feeding the paper traveling on the traveling path set between the print head and the platen arranged facing the platen, and when a part of these rollers is left and retracted from the paper traveling path, By sharing the spring member of one roller with the spring member of another roller, the mechanism is simplified and the manufacturing cost is reduced.

[Brief description of drawings]

FIG. 1 is a side view of a cut sheet according to an embodiment of the present invention when traveling.

FIG. 2 is a side view showing a state in which continuous paper is running on the tractor feeder of this embodiment.

FIG. 3 is a front view of the pressure roller portion from which the platen of this embodiment is removed.

FIG. 4 is a side view showing a state in which continuous paper is running on a tractor feeder of a conventional example.

[Explanation of symbols]

 1 Print Head 2 Platen 3-a, 3-b, 3-c Pressure Roller 4 Roller Support 5 Lever 6 Paper Guide 7 Stay 8 Shaft 9 Brackets 10, 11, 20 Pressure Spring 12 Front Roller Support 13 Paper Guide 14 Feed Roller 15,16 Continuous paper 17,18 Tract feeder 19 Spring

Claims (2)

[Claims] 1. A serial printer having a plurality of rollers for feeding a sheet traveling on a traveling path set between a print head arranged facing a platen and the platen, wherein a part of the rollers is provided. A serial printer characterized in that, when retracted from the remaining sheet traveling path, some of the spring members of the rollers are shared with the spring members of the other rollers. 2. A first supporting member for holding a plurality of rollers for inserting a sheet from the rear of a platen and holding the sheet together with the platen, and inserting the sheet from the lower side of the platen to insert the sheet. A second supporting member that holds a driving roller of a pair of rollers that are gripped and travels, and a second supporting member that rotatably supports the first supporting member and the second supporting member via a first spring member. A plurality of third support members that rotate and interlock with a lever that switches between running of cut sheets and continuous paper, and the first support member and the second support member are engaged with each other. A second spring member that retracts a part of the rollers from the platen and presses the other parts of the plurality of rollers against the platen with a very weak pressure to stably run the continuous paper. Serial printer to do.