JPH0120129Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a paper bail roller for a printer.

[Technical background of the invention and its problems]

Printers equipped with a platen require a paper bail roller to press the paper against the platen. The paper bail roller is rotatable and needs to be moved in the axial direction depending on the width of the paper used.

Conventionally, as shown in FIG. 1, a stop spring 2 is attached to the inner peripheral surface of a cylindrical paper bail roller 1.
There is a device in which a groove is formed in which the paper bail roller 1 is fitted, and the paper bail roller 1 is positioned at an arbitrary position on the paper bail shaft 3 by friction between the stop spring 2 and the paper bail shaft 3. Since the paper has a cylindrical shape, the edge portion 4 on the periphery of the end presses against the paper, leaving a pressure mark when using carbon paper or pressure-sensitive paper. When knurling is formed on the outer periphery of the paper bail roller 1 to prevent slipping, burrs are likely to form on the edge portion 4, and traces of pressure contact will be noticeable. Furthermore, the problem of the stop spring 2 causing damage to the paper bail shaft 3 remains unsolved. Assembly and disassembly of the stop spring 2 is also extremely difficult.

As shown in Fig. 2, by fitting a soft outer ring 6 made of rubber or the like to a paper bail roller 5 with a flange, it is possible to prevent pressure marks from being left when carbon paper or pressure-sensitive paper is used. However, in order to position the paper bail roller 5 at an arbitrary position on the paper bail shaft 3, the stop spring 2 is installed inside the paper bail roller 5, so the paper bail shaft 3 will still be damaged. Furthermore, the number of parts also increases. Furthermore, since the soft outer ring 6 absorbs ink, the ink on the printing surface may be transferred to other parts of the paper, which is inconvenient.

[Purpose of invention]

This invention was made in view of the above points, and the purpose is to provide a paper bail roller for a sprinter that has a small number of parts, is easy to assemble, and does not have a negative effect on printing quality. .

[Summary of the invention] This invention rotatably connects a drum-shaped wheel whose center diameter is the largest and a brake body, fits both into a paper bail shaft, and connects the flexible piece of the brake body to the brake body. The braking body is placed in pressure contact with the outer circumference of the paper bail shaft, and is positioned along with the wheel on any axis of the paper bail shaft, and only the wheel rotates at that position to hold down the paper, thus reducing the number of parts. The brake body is made of plastic to prevent scratches on the paper bail shaft, and the wheel that presses the paper is shaped like a drum to avoid any marks caused by pressure contact on the paper. This structure is designed to prevent this from occurring.

[Example of idea]

An embodiment of this invention will be explained based on FIGS. 3 and 4. The wheel body 7 and the brake body 8 are made of elastic plastic. Braking body 8
is made up of a disk portion 9 and a plurality of flexible pieces 10, and the inner diameter of each flexible piece 10 is tapered, and its minimum dimension is equal to that of the paper bail shaft 11.
smaller than the diameter of Further, each flexible piece 10 bends outward due to external force, but returns inward due to its own elasticity. The wheel body 7 has a drum-shaped outer periphery with a larger diameter at the center, and has a fitting hole 1 on the inner periphery into which the paper bail shaft 11 is rotatably fitted.
2 is formed. Thus, an annular groove 13 serving as an engaging portion is formed on the inner periphery of the wheel body 7, and a semicircular protrusion 14 serving as an engaging portion is formed on the outer periphery of the end of the flexible piece 10 of the brake body 8. There is.

In such a configuration, the wheel body 7 and the brake body 8 are fitted into the paper bail shaft 11, and the projection 14 is elastically engaged with the annular groove 13. Thereby, the wheel body 7 and the brake body 8 are connected coaxially. The flexible piece 10 elastically presses the paper bail shaft 11 and is fixed on the paper bail shaft 11 by its frictional force, but the brake body 8 and the wheel body 7 are slid against the frictional force. It can be positioned at any position. The wheel 7 that presses the paper at this arbitrary position rotates while being supported by the paper bail shaft 11 and the brake body 8 as the paper is fed.

The wheel body 7 and the brake body 8 push the disk part 9 and the protrusion 1
4 is connected by press-fitting into the annular groove 13,
Disassembly is performed by pulling the disc portion 9, and the number of parts is small, making assembly and disassembly work extremely easy.

Since the paper is held down only by the center of the ring 7, it is not pressed against the end periphery 15 of the ring 7 or the periphery 16 of the disc portion 9, and even if carbon paper or pressure-sensitive paper is used, the paper will not be pressed against the periphery 15, There will be no trace of 16. The wheel body 7 also does not transfer ink and does not adversely affect printing quality. Since the brake body 8 is also made of plastic, the movable piece 10 will not damage the paper bail shaft 11.

[Effect of idea]

Since this invention is constructed as described above, the braking body held at any position on the paper bail shaft and the wheel joined to the paper can be assembled and disassembled extremely easily, and the number of parts is reduced. Furthermore, by forming the wheel into a drum shape, it is possible to prevent marks from being left on the paper due to pressure contact of the outer circumference of the end of the wheel. It is possible to prevent printing ink from being transferred to the paper, and furthermore, since the brake body is made of plastic, it is possible to prevent the paper bail shaft from being scratched.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are exploded perspective views showing a conventional example;
Figure 3 is a sectional view showing one embodiment of this invention;
The figure is a sectional view showing the assembled state. 7... Wheel body, 8... Braking body, 10... Flexible piece,
11...Paper bail shaft, 13...Annular groove (engaging portion), 14...Protrusion.

Claims (1)

[Scope of utility model registration request] A wheel is provided in a drum-like shape with a maximum outer diameter at the center and rotatably and slidably fitted to the paper bail shaft. A brake body having a flexible piece that presses against the outer periphery of the paper bail shaft due to its elasticity is molded from elastic plastic, and the wheel body and the brake body are rotatably fitted and the two are fitted together. 1. A paper bail roller for a printer, characterized in that engaging portions are formed that elastically engage with each other and connect each other in the axial direction.