JPS6140177A - Platen roller - Google Patents

Abstract

PURPOSE:To provide a platen roller which is light in weight and generates little noise, by providing a closed-cell rigid foamed polyurethane resin layer on a metallic shaft, and providing a non-foamed rigid polyurethane resin skin layer thereon. CONSTITUTION:The rigid foamed polyurethane resin layer 20 with a closed-cell structure is provided on the metallic shaft 1 to contrive simultaneously a lighter weight and lower noise. Namely, a lighter weight is contrived by the use of a foamed material, and sound transmitting property is decreased and sound-absorbing property is increaded by providing the foamed polyurethane resin with the closed-cell structure. In addition, the non-foamed rigid polyurethane resin layer 21 is provided as the outermost layer in order to give smooth finish to the surface of the platen roller, thereby ensuring clear printing.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a novel platen roller.

More specifically, the present invention relates to a platen roller used in a printer.

[Prior Art 1] A platen roller is used in an impact printing type printer such as a typewriter. As shown in FIG. 2, a conventional platen roller has a metal shaft 1 passing through its center, and is made by heat-molding hard ebonite rubber 2 onto the metal shaft 1 into a cylindrical shape. Since both the metal shaft 1 and the ebonite rubber 2 have a high density, the platen roller f! The portions are large. ff
A platen roller with a large capacity of 1 liter naturally consumes a large amount of driving energy, leading to an increase in the size of the drive motor, the size of the 1L unit, an increase in electric power, and an increase in 1L noise.

For this reason, various measures to reduce the weight of the platen roller have been studied. For example, measures include using a hollow metal pipe as the metal shaft 1 and using hard ebonite rubber with a low density.

However, the use of a hollow metal shaft has the disadvantage of increased noise due to the resonance edges within the hollow metal shaft.

On the other hand, lowering the density of hard ebonite is achieved by reducing the amount of sulfur and filler added, which leads to a decrease in the hardness of ebonite rubber by 1 strong mark. It is also possible to foam ebonite rubber, but this method is technically extremely difficult.

[Problems to be Solved by the Invention] The present invention has been made based on the above points, and its purpose is to solve the drawbacks of the prior art described above and to provide a lightweight and low-noise platen. Our goal is to provide rollers.

[Means for Solving the Problems] The gist of the present invention is that there is a metal shaft passing through the metal shaft, a closed-cell hard urethane foam resin layer is provided on the metal shaft, and the closed-cell hard urethane foam resin layer is formed on the metal shaft. The platen roller is characterized in that a non-foamed hard urethane resin skin layer is provided on top of the resin layer.

In the present invention, the metal shaft may be one used in conventional platen rollers, such as a stainless steel shaft, a brass shaft, an aluminum shaft, etc. The metal shaft is usually a round bar with a diameter of 8 am to 25 am, but depending on the application, it may have a modified cross-sectional structure.

In addition, in the present invention, the rigid foamed urethane resin refers to, for example, R-1 when a polyol and a polyisocyanate are reacted to obtain a polymer having a so-called urethane bond.
It is obtained by mixing a fluorocarbon solution such as 1 or a very small amount of water as necessary to gasify the fluorocarbon solution or create a nearly independent cell structure by generating carbon dioxide gas. Either polynisder urethane resin or polyether urethane resin can be used. Furthermore, although it is a known technique, the size and distribution of bubbles can be made uniform by using a so-called foam stabilizer such as a silicon compound. Furthermore, the resin hardness of this hard foamed urethane resin when not foamed is suitably 45 or more in Shore D. If the resin hardness is less than 45, it is not practical because dents due to impact during printing are large and the printed outline becomes unclear. In addition, the foaming ratio of the rigid urethane foam resin is not limited as long as the desired light 1 curing can be obtained and there are no problems with printing performance, but In order to prevent bending, it is preferable to set it to 4.5 times or less.

In the present invention, the thickness of the hard urethane resin layer provided on the hard urethane foam resin layer is preferably 0.15 jw or more.

That is, if the thickness of the hard urethane resin is less than 0.15 m, it cannot sufficiently withstand the impact during printing.

[Function] The effect of the present invention is that by providing a hard foamed urethane resin layer with a closed cell structure on the upper layer of the metal shaft, weight reduction and noise reduction are achieved at the same time. That is, the weight is reduced by using a foam, and the foamed urethane resin having a closed cell structure reduces sound propagation and increases sound absorption. Further, the reason why the non-foamed hard urethane resin layer is provided as the outermost layer is to make the surface of the platen [1-ra] smooth and to print clear characters.

[Example] Next, Examples and Comparative Examples of the platen roll of the present invention will be described.

Table 1 shows the foaming rate of the hard urethane foam resin layer.

Platen rollers with varying hardness and the thickness of the hard urethane resin skin layer were prototyped and evaluated and compared with conventional platen rollers. No, 1~
3 is a comparative example, No. 4 to 9 are examples, and No. 10 is a conventional example.

FIG. 2 is a longitudinal sectional view showing an embodiment of the platen roller of the present invention, and FIG. 3 is an explanatory diagram of a noise reduction evaluation test.

In the noise reduction evaluation test, as shown in FIG. 3, a platen roller was attached to the printer, and the sound during printing was measured with a sound level meter via a microphone, and the peak sound was evaluated.

As is clear from the first effect, the platen roller of the present invention has the same printing performance as the conventional platen roller,
Furthermore, it is lightweight and has low noise. Also, the platen roller has relatively poor printing performance.

As described in detail above, the platen roller of the present invention is lightweight and generates little noise during printing, and as a result, it can be used in various printers and the like, and is industrially useful.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the platen roller of the present invention, FIG. 2 is a longitudinal sectional view of a conventional platen roller, and FIG. 3 is an explanatory diagram of a noise measurement test during printing. 1: Metal shaft, 2: Hard ebonite layer. 3: Braden roller, 4: Print head. 5: Paper, 6: Microphone, 7: Noise reduction. 20: Hard urethane resin layer, 21: Hard urethane resin layer, Deaf

Claims (1)

[Claims] There is a penetrating metal shaft, a closed-cell hard foam urethane resin layer is provided on the metal shaft, and a non-foamed hard urethane skin resin skin layer is provided on the closed-cell hard foam urethane resin layer. Features a platen roller.