JPH04176672A - Core material of platen roll - Google Patents

Abstract

PURPOSE:To enhance noise muffling effects by providing a sleeve and an inner pipe, both being made of light metal, and introducing the inner pipe into the sleeve in a non-adhesive, tightly contacting manner. CONSTITUTION:The core material of a platen roll consists of a sleeve 1 and an inner pipe 2 made of light metals such as aluminum or its alloy. The inner pipe 2 is introduced in the sleeve in a non-adhesive, tightly contacting state. Subsequently, an air layer is present between the sleeve 1 and the inner pipe 2 under such a state. In addition, micro-projecting and recessed patterns are formed at random over the entire surface of a contact area between the sleeve 1 and the inner pipe 2. In addition, a notched groove 3 is provided in the longitudinal direction of the sleeve 1 or the inner pipe 2. That is, the air layer formed between the sleeve 1 and the inner pipe 2 reduces part of a beating sound being transmitted from a coated member 4 to the platen roll core material. After that, micro-projecting and recessed points formed on the contact surface between the sleeve 1 and the inner pipe 2 work to interrupt the generation of resonant waves of various modes.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a core material of a platen roll,
Specifically, the present invention relates to a core material for a platen roll that has been improved by adopting a specific cylindrical structure to achieve a high noise reduction effect.

[Conventional technology]

Conventionally, platen rolls have been used in printers, typewriters, and the like.

The platen roll includes a shaft portion connected to a shaft for driving platen rotation, a core material connected to the shaft portion, and a covering member (platen rubber) fitted to the core material.

Since the core material of the platen roll is desired to be lightweight, a core material made of a cylindrical body made of light metal is preferably used.

[Problem to be solved by the invention]

However, the core material made of a cylindrical body has a drawback that the hammering sound during printing reverberates in the space of the core material and generates noise.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide a core material for a platen roll that is improved so as to provide a high sound-dampening effect.

[Means to solve the problem]

That is, the gist of the present invention is a core material of a platen roll into which a covering member is fitted, and is composed of an outer cylinder and an inner cylinder made of light metal, and the inner cylinder is attached to the outer cylinder in a non-adhesive state. The outer cylinder and the inner cylinder are inserted, and minute irregularities are randomly formed on the entire contact surface of the outer cylinder and the inner cylinder, and furthermore, the outer cylinder or the inner cylinder is characterized by having notched grooves in the longitudinal direction thereof. It is present in the core material of the platen roll.

Hereinafter, the present invention will be explained in detail based on the accompanying drawings.

1 and 2 are explanatory diagrams showing an example of the core material of the platen roll of the present invention, FIG. 1 is a side explanatory diagram, and FIG.
The figure is an explanatory cross-sectional view taken along line A-A in FIG. 1.

The core material of the platen roll of the present invention is an outer cylinder (1) and an inner cylinder (2) made of light metal such as aluminum or its alloy.
It consists of

The inner cylinder (2) is inserted into the outer cylinder (1) in a non-adhesive, close contact state. Here, the term "non-adhesive, close contact state" refers to a state in which both are mechanically pressed and brought into close contact without being adhered with an adhesive or the like. Therefore, in such a state, an air layer exists between the outer cylinder (1) and the inner cylinder (2).

Further, minute irregularities are randomly formed on the entire contact surface of the outer cylinder (1) and the inner cylinder (2).

The above-mentioned irregularities usually have a height of 2 to 15 microns, and are formed randomly in the longitudinal direction without being continuous in the circumferential direction of the contact surface.

Furthermore, the outer cylinder (1) or the inner cylinder (2) is provided with a notch groove (3) in its longitudinal direction. The notch groove (3) may be provided over the entire longitudinal direction of the outer cylinder (1) or the inner cylinder (2), or may be provided except for both ends. Then, the notch groove (3
) should normally be in the range of 0°5 to 3 nm. The number of cutout grooves (3) may be one, or if two or more are provided, it is preferable to provide them at irregular intervals. For example, in the case of three, for one notch groove (3), the other two
It is preferable that the books be formed at positions deviating from the equal positions by 10° or more, such as at positions 105° and 135°, rather than at positions 120° on the left and right.

The core material of the platen roll of the present invention can be easily manufactured by, for example, the following drawing process.

First, the inner cylinder (2) is inserted into the outer cylinder (1) and one end is sealed to form a fixed end. Then, from the other open end,
Insert the double pipe into the die so that the plug is placed inside the double pipe (on the inner surface of the inner cylinder (2)) and draw it at a predetermined pressure to separate the outer cylinder (1) and the inner cylinder. (2) According to the above-mentioned drawing process, the inner cylinder (2) is integrated with the inner cylinder (2).
) is inserted into the outer cylinder (1) in a non-adhesive, close contact state, and the entire contact surface of the outer cylinder (1) and the inner cylinder (2) has a circumferential surface due to friction during the drawing process. Fine wrinkle-like irregularities that are not continuous are formed randomly over the entire lengthwise direction.

Next, a notch groove (3) is formed in the longitudinal direction of the outer cylinder (1) or the inner cylinder (2) by machining. And the inner cylinder (2)
In the case of forming the notch groove (3) only in the groove, it is convenient to use, for example, broaching. In addition, the above notch groove (3
) can also be formed at the same time as the above-mentioned drawing process by using a plug having an appropriate convex portion.

In addition to the above-described method using the drawing process, the core material of the platen roll of the present invention can be formed by forming an inner cylinder (2) inside an outer cylinder (1).
It can also be easily manufactured by a method in which the outer tube (1) and the inner tube (2) are integrated by inserting the inner tube and sealing one end to form a fixed end, and then ironing the outer tube (1) and the inner tube (2).

The core material of the platen roll of the present invention is used by being connected to a shaft portion (6) in which a covering member (platen rubber) (4) is fitted and connected to a shaft (5) for driving platen rotation.

The core material of the platen roll of the present invention achieves a high noise reduction effect by employing the specific cylindrical structure as described above, and this is considered to be based on the following effect.

That is, the air layer formed between the outer cylinder (1) and the inner cylinder (2) attenuates a part of the hitting sound from the covering member (4) toward the platen roll core material, and ) and the minute irregularities formed on the contact surfaces of the inner cylinder (2) act to prevent the generation of resonance waves in various modes, and as a result, a high noise reduction effect is exhibited.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

Example 1 An extruded aluminum tube with an outer diameter of 35 mm and an inner diameter of 30 mm was used as an outer cylinder, and an extruded aluminum tube with an outer diameter of 28 mm and an inner diameter of 25 mm was used as an inner cylinder, and the core material of the platen roll shown in FIGS. 1 and 2 was manufactured. .

First, the inner cylinder was inserted into the outer cylinder, one end of the inner cylinder was sealed, and the other open end was drawn to form a double tube with an outer diameter of 28 mm and an inner diameter of 25 mm.

After cutting the above double pipe to a length of 400 mm, 10 m from both ends
A core material for a platen roll was manufactured by machining one notch groove with a width of 1.5 mm in the longitudinal direction only on the outer cylinder, excluding the m width.

Example 2 In Example 1, three notch grooves were provided at unequal intervals (for one notch groove, the other two were at 105° on the right and left sides).
A core material for a platen roll was manufactured in the same manner as in Example 1, except that the core material was formed at an angle of 135°.

Example 3 A core material for a platen roll was manufactured in the same manner as in Example 1, except that one notch groove was provided over the entire longitudinal direction.

Example 4 A core material for a platen roll was manufactured in the same manner as in Example 1, except that one notched groove was provided only in the inner cylinder over the entire longitudinal direction.

Comparative Example 1 (Core material without double-layer structure) A drawn aluminum tube having an outer diameter of 28 mm and an inner diameter of 25 mm was individually cut into a length of 400 mm to be used as a core material for a platen roll.

Comparative Example 2 (Core material with double-wall structure without cutout grooves) A core material for a platen roll was produced in the same manner as in Example 1, except that the cutout grooves were not provided in Example 1.

A platen rubber having a thickness of 30 mm was fitted into each platen roll core material prepared in Examples 1 to 4 and Comparative Examples 1 to 2, and a shaft connected to a shaft for driving the platen rotation of a printer was inserted from both ends. The noise reduction effect was compared by connecting the two printers and driving four printers.

The above comparison results are shown in Table 1, with the lowest noise level being set as 0.

Table 1 As is clear from the results in Table 1, it can be seen that the present invention is effective in silencing platen rolls.

〔Effect of the invention〕

According to the present invention described above, there is provided a core material for a platen roll that is improved by adopting a specific cylindrical structure so that a high noise reduction effect can be obtained.

[Brief explanation of drawings]

1 and 2 are explanatory diagrams showing an example of the core material of the platen roll of the present invention, FIG. 1 is a side explanatory diagram, and FIG.
The figure is an explanatory cross-sectional view taken along line A-A in FIG. 1. In the figure, (1) is the outer cylinder, (2) is the inner cylinder, (3) is the notched groove,
(4) represents a covering member, (5) represents a shaft for driving platen rotation, and (6) represents details.

Claims (1)

[Claims] (1) A core material of the platen roll into which the covering member is fitted, and is composed of an outer cylinder and an inner cylinder made of light metal, and the inner cylinder is inserted into the outer cylinder in a non-adhesive state, A core material for a platen roll, characterized in that minute irregularities are randomly formed on the entire contact surface of the outer cylinder and the inner cylinder, and furthermore, the outer cylinder or the inner cylinder is provided with notched grooves in the longitudinal direction thereof. .