JP3064729B2 - Printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer for printing characters and figures. More specifically, the present invention relates to a tractor that transports continuous paper.

[0002]

2. Description of the Related Art In recent years, with the rapid spread of microcomputers used in a general environment, a highly reliable printer which is hardly influenced by factors such as temperature and humidity of an environment in which a printer is used and an environment in which printing paper is stored. Is required. In response to this demand, there has been proposed a paper feed mechanism adapted to cope with expansion and contraction of the print paper in the width direction caused by environmental factors such as humidity.

[0003] For example, a paper feed mechanism as disclosed in Japanese Patent Application Laid-Open No. 3-216647 is known. The contents disclosed here will be described with reference to FIGS. The right tractor unit 101 and the left tractor unit 102 are combined with the drive shaft 103 and the guide shaft 10.
4 and each tractor unit is fixed to an arbitrary position on the guide shaft 104 by lock levers 105 and 106. Each tractor unit has a pin 107, 1 which engages a paper feed hole formed on both sides of the continuous paper.
Track tractor belts 109, 11 provided with
Reference numeral 0 extends between toothed pulleys (not shown) and is arranged so as to be driven by the power of the drive shaft 103. Further, each tractor unit 101, 102 is provided with paper holding plates 111, 112 which can be freely opened and closed by hinges 113, 114, so that continuous paper can be set in an open state and paper can be fed while holding the continuous paper in a closed state. It has become. Further, the paper holding plates 111, 1
Reference numeral 12 is urged by coil springs 115 and 116 so as to be stable in both the closed state and the open state. FIG. 4 shows a state in which the sheet press plate 111 is open, and FIG. 5 shows a state in which the sheet press plate 111 is closed. In the right tractor unit, a coil spring 119 is interposed between the frame 117 and a toothed pulley (not shown) to urge the tractor belt 109 to the right.

When setting continuous paper, the paper holding plate 1
11 and 112, the left tractor unit 102 is fixed to the guide shaft 104 by the lock lever 106 at a predetermined position, and the paper feed hole formed on the left side of the continuous paper is engaged with the pin 108 to close the paper holding plate 112. . Thereafter, the right tractor unit 101 is moved to a position where the pin 107 of the right tractor unit 101 engages with the paper feed hole formed on the right side of the continuous paper, the continuous paper is set, and the paper holding plate 111 is closed. Since the tractor belt 109 of the right tractor unit 101 can slide in the left-right direction between the frames 117, the tractor belt 109 is positioned at an intermediate position in the left-right slidable range while resisting the urging force of the coil spring 119. Right tractor unit 101
To the right, and guide the shaft 1 with the lock lever 105.
04 fixed.

[0005] Even if the continuous paper set in this manner expands and contracts in the width direction due to moisture absorption or drying during use, the tractor belt 109 of the right tractor unit 101 slides in the left and right direction in accordance with the expansion and contraction. 108 is intended to enable stable paper feed without slipping out of the paper feed hole of continuous paper.

[0006]

However, in the above configuration, the pin 107 of the right tractor unit 101 is not provided.
Move relative to the frame 117, the pin 107 also moves relative to the paper holding plate 111 attached to the frame 117, and the pin 107 is provided to escape the pin 107 as much as possible in response to this movement. Hole 12
It is necessary to increase the width of zero. That is, the vicinity of the paper feed hole of the continuous paper cannot be firmly pressed by the paper holding plate 111, and the continuous paper is likely to be disengaged from the pin 107.

Further, when setting continuous paper, the user is forced to perform such a troublesome operation as described above. In particular, the right tractor unit 101 is moved to the right so that the tractor belt 109 is located at an intermediate position of the slidable range in the left-right direction while being opposed to the urging force of the coil spring 119, and is fixed to the guide shaft 104 by the lock lever 105. Is an operation that is not only difficult for unfamiliar users, but also easy to forget. If the user forgets, the user can cope with the case where the continuous paper contracts in the width direction during use.
Since 09 does not move in the width direction, the pin 107 is displaced from the paper feed hole, and the paper cannot be fed.

An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to provide a printer which can stably feed paper even if the width of continuous paper set in the printer expands and contracts during use due to a change in environmental conditions. Is to do.

[0009]

According to the present invention, there is provided a printer having a tractor capable of transporting continuous paper by engaging pins with paper feed holes continuously punched on both sides of the continuous paper. A tractor frame is provided with a permanent magnet, and a frame provided with a permanent magnet is provided so as to be movable relative to the tractor frame in opposition to the permanent magnet.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are plan views showing a tractor set of a printer according to an embodiment of the present invention. The tractor set includes a right tractor unit 1 and a left tractor unit 2. The right tractor unit 1 and the left tractor unit 2 are supported by the drive shaft 3 and the guide shaft 4 and can be fixed to arbitrary positions on the guide shaft 4 by lock levers 5 and 6. The left tractor unit 2 is a left tractor unit 10 described as a related art.
2, the description thereof is omitted here, and the right tractor unit 1 will be described. A caterpillar-shaped tractor belt 9 having pins 7 engaging with paper feed holes 22 formed on both sides of the continuous paper is stretched between toothed pulleys (not shown) and arranged so as to be driven by the power of the drive shaft 3. I have. The frame 17 is provided with a sheet holding plate 11 which can be opened and closed by a hinge 13 so that continuous sheets can be set in an open state and can be fed while holding the continuous sheets in a closed state. The paper holding plate 11 is provided with a coil spring 15
Are biased so as to be stable in both the closed state and the open state. FIG. 1 shows a state in which the sheet press plate 11 is open, and FIG. 2 shows a state in which the sheet press plate 11 is closed. On the right side of the frame 17, a tension generating frame 23 is supported by shafts 24 and 25 so as to be slidable in the left-right direction with respect to the frame 17. The tension generating frame 23 is provided with a lock lever 5 so that the right tractor unit 1 can be fixed at a predetermined position on the guide shaft 4. A permanent magnet unit 26 is provided on the right side surface of the frame 17, and a permanent magnet unit 27 is provided on the tension generating frame 23 so as to face the permanent magnet unit 26. The operation between the permanent magnet units 26 and 27 will be described with reference to FIG. FIG.
(A) shows a state in which the lock lever 5 is released and the right tractor unit 1 can freely slide left and right with respect to the guide shaft 4. The permanent magnet units 26 and 27
Each magnet is divided and magnetized with N, S, N, S, and the same pole faces each other. Due to the repulsive force between the magnetic poles, the tension generating frame 23 and the frame 17 are urged in directions to move away from each other. The lock lever 5 is provided with a pinion 28. A rack 29 is slidably provided on the tension generating frame 23 by engaging with the pinion 28, and a permanent magnet unit 27 is provided on a side surface of the pinion. That is, when the lock lever 5 is rotated, the permanent magnet unit 27 slides while facing the permanent magnet unit 26, so that the opposing magnetic poles can be changed. FIG. 3B shows a state in which the lock lever 5 is locked and the tension generating frame 23 is fixed to the guide shaft 4. The permanent magnet units 26 and 27 have different poles facing each other. The tension generating frame 23 is generated by the attractive force between the magnetic poles.
And the frame 17 are urged in a direction to approach each other.

When setting continuous paper, the paper holding plate 1
1 and 12, the left tractor unit 2 is fixed at a predetermined position to the guide shaft 4 by the lock lever 6, and the paper feed hole 22 drilled on the left side of the continuous paper is engaged with the pin 8 so that the paper holding plate 12 is pressed. close. Thereafter, the right tractor unit 1 is moved to a position where the pin 7 of the right tractor unit 1 is engaged with the paper feed hole 22 formed on the right side of the continuous paper, the continuous paper is set, the paper holding plate 11 is closed, and the lock lever 5 is closed. Is rotated to fix the tension generating frame 23 to the guide shaft 4. As the lock lever 5 rotates, FIG.
The state transitions from the state of FIG. 3A to the state of FIG.
No. 7 is urged rightward, and a transverse tension is automatically generated in the continuous paper. Even if the continuous paper expands and contracts due to environmental changes such as temperature and humidity due to the lateral tension, the frame 17 follows this and always applies an appropriate lateral tension to the continuous paper, and a jam occurs due to continuous paper conveyance. There is no. Further, since the pins 7 do not move in the left-right direction with respect to the sheet pressing plate 11, the width of the hole 20 provided in the sheet pressing plate 11 to escape the pins 7 can be reduced. That is, the paper holding plate 11 can firmly hold the vicinity of the engagement position between the pin 7 and the paper feed hole 22,
Stable continuous paper transport can be realized without the pins 7 coming off the paper feed holes 22.

[0012]

As described above, according to the printer of the present invention, since the permanent magnets are provided opposite to the frame of the tractor unit and the tension generating frame, the continuous paper can be set by a simple operation and the continuous paper can be set. Even if the paper width expands or contracts during use due to a change in environmental conditions, the paper can be fed stably.

[Brief description of the drawings]

FIG. 1 is a plan view showing a tractor set of a printer according to an embodiment of the present invention.

FIG. 2 is a plan view showing a tractor set of the printer according to the embodiment of the present invention.

FIG. 3 is a diagram illustrating an operation between permanent magnet units according to the present invention.

FIG. 4 is a plan view showing a conventional tractor set.

FIG. 5 is a plan view showing a tractor set according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Right tractor unit 2 Left tractor unit 3 Drive shaft 4 Guide shaft 5 Lock lever 6 Lock lever 7 Pin 8 Pin 9 Tractor belt 10 Tractor belt 11 Paper press plate 12 Paper press plate 13 Hinge 14 Hinge 15 Coil spring 16 Coil spring 17 Frame Reference Signs List 20 hole 21 hole 22 paper feed hole 23 tension generating frame 24 axis 25 axis 26 permanent magnet unit 27 permanent magnet unit 28 pinion 29 rack

Claims (1)

(57) [Claims] In a printer having a tractor capable of transporting the continuous paper by engaging pins with paper feed holes continuously punched on both sides of the continuous paper, a permanent magnet is provided on a frame of the tractor. A printer comprising: a frame provided with a permanent magnet facing the permanent magnet so as to be relatively movable with respect to the frame of the tractor.