JPS60259475A - Platen - Google Patents

Abstract

PURPOSE:To stably reduce nose of printing all the time by providing plural holes lending the periphery of a hollow cylinder with the hollow filled with a sound absorber. CONSTITUTION:Plural holes 1a leading to the hollow of a hollow cylinder 1 are drilled in the peripheral surface of the cylinder 1 covered with a rubber ealstic material 4. The hole 1a has a diameter enough small not to interrupt printing and a round form, and the holes 1a are axially drilled at an equal interval in relation to the circumferential direction of the peripheral surface by biasing their positions alternately. The holes 1a also are drilled vertically to the circumferential direction and also toward the center of the cylinder 1. The holes 1a, together with a sound absorbers 5 packed into the hollow of the cylinder 1, serve to absorb the noise of printing. Also, since the sound absorptive regions of the holes 1a and the sound absorber 5 are different, the noise of printing can be exactly reduced with their mutual compensatory effects.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a platen used in a printing mechanism of a printer, typewriter, etc., and particularly to a platen having a structure for reducing printing noise.

[Prior Art] Conventionally, the internal structure of the platen of the printing mechanism of printers, typewriters, etc. has generally been a simple pipe structure, solid aluminum structure, etc., and in terms of countermeasures against printing noise, sound-absorbing effects have been added to the inside of the pipe. The reality is that the printing noise is reduced by using materials that have the same properties.

However, with conventional methods, depending on the predetermined printing noise frequency, there may be little effect of reducing printing noise, or conversely, the printing noise may increase, making it difficult to always obtain a stable printing noise reduction effect. There was a drawback that there was no

[Object of the Invention] The present invention solves the above-mentioned drawbacks, and provides constant printing noise by providing a plurality of holes that communicate with the outer peripheral surface of the hollow cylindrical body and the hollow part filled with a sound-absorbing material. It is an object of the present invention to provide a platen that can reduce the amount of damage.

[Structure of the Invention] The structure of the platen according to the present invention to achieve the above-mentioned object of the present invention is a platen made of a hollow cylinder whose outer peripheral surface is coated with a rubber-like elastic material and whose hollow part is filled with a sound absorbing material. In this case, a plurality of holes are bored through which the outer circumferential surface and the hollow part communicate with each other.

[Explanation of Examples] Next, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a sectional view showing one embodiment of a platen according to the present invention.

FIG. 2 is a schematic perspective view with a part of the surface of the platen of the same embodiment cut away.

In the figure, l is a hollow cylinder with both ends open, and this hollow cylinder 1
A circular flange 2.2 is integrally fitted into both open ends of the hollow cylindrical body 1, and a flange 2.2 is fitted at both ends of the hollow cylindrical body 1. , cylindrical platen shafts 3, 3 are fixed in the axial direction of the hollow cylindrical body 1. The axes of the platen shafts 3, 3 and the axis of the hollow cylindrical body 1 are aligned. The platen shaft 3.3 receives driving force from a drive source of the main body of the apparatus, such as a typewriter (not shown), and functions to rotate the hollow cylindrical body l. A rubber-like elastic body 4 having a predetermined thickness is coated over the entire outer peripheral surface of the hollow cylinder 1, excluding both ends where the flange 2.2 is fitted. It functions to absorb shock during printing. The electrically sealed hollow portion of the hollow cylindrical body l is filled with a sound absorbing material 5 that absorbs printing noise. The sound absorbing material 5 may be made of a rubber material, for example. The platen is made up of these members.

A plurality of holes 1a communicating with the hollow portion are bored on the outer peripheral surface of the hollow cylinder 1 covered with the rubber-like elastic body 4. The hole 1a has a circular shape with a small diameter that does not interfere with printing. The holes 1a are bored at equal intervals in the circumferential direction of the outer peripheral surface, and the holes 1a are bored at equal intervals in the axial direction, with the positions of the holes 1a being alternately shifted. This hole 1a is perpendicular to the outer circumferential surface and is bored toward the center of the hollow cylindrical body 1. The holes 1a have the effect of absorbing printing noise together with the sound absorbing material 5 filled in the hollow portion. The holes 1a and the sound-absorbing material 5 each have a region in which they cannot absorb printing noise of different frequencies, but since the regions are different between the holes 1a and the sound-absorbing material 5, they complement each other to reliably absorb printing noise and reduce it. We are trying to

Note that the shape of the hole 1a may be, for example, an ellipse, and does not necessarily have to be circular. Also, the diameter of the hole 1a is the diameter of the hollow cylinder 1.
The outer circumferential surface and the inner circumferential surface may be different. Furthermore, the holes 1a may not be alternately shifted in the axial direction, but may be at the same position.

[Effects of the Invention] As explained above, according to the platen according to the present invention,
By drilling multiple holes that communicate between the outer circumferential surface of the hollow cylinder and the hollow part filled with sound-absorbing material, printing noise of a predetermined frequency that cannot be absorbed by the sound-absorbing material alone can be absorbed into the hollow cylinder. It is possible to reliably absorb the printing noise through the holes, and it is possible to achieve the effect of always stably reducing printing noise.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of a platen according to the present invention. FIG. 2 is a schematic perspective view with a part of the surface of the platen of the same embodiment cut away. 1... Hollow cylinder Ia... Hole 2 Flange 3e1 Platen shaft 4... Rubber-like elastic body 5... Sound absorbing material

Claims (1)

[Claims] A platen comprising a hollow cylinder whose outer peripheral surface is coated with a rubber-like elastic material and whose hollow part is filled with a sound absorbing material, characterized in that a plurality of holes are bored through which the outer peripheral surface and the hollow part communicate with each other. platen.