JPS58109714A - Pinch roller and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a pinch roller inexpensive to manufacture and having excellent tape forwarding performance by a method wherein the outer surface of a boss is made convexly and a cylindrical rubber roller with a uniform thickness is fitted onto the boss in such a manner that the surface parted from mold of the rubber roller faces outward. CONSTITUTION:The boss 3 is formed so that its outer surface 32 is convex with a suitable curve. On the other hand, in order to obtain the rubber roller 4, at first a rubber cylinder with a proper thickness is made by means of metallic mold or the like. Secondly, its surface is ground until the roller 4 with a predetermined thickness is obtained. After that, the rubber roller 4 is turned inside out or the inner surface contacted with the mold goes outside and the ground outer surface goes inside. The rubber roller 4 turned inside out is fitted onto the outer surface of the boss 3. By making the rubber roller 4 in such a manner as mentioned above, the grinding work of the surface 41 of the rubber roller 4 after the rubber roller 4 being fitted on the boss 3 is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION This paper relates to a pinch roller used in a tape feeding mechanism of a tape recorder, video deck, etc., and a method of manufacturing the same.

As a pinch roller used in a tape feeding mechanism of a tape recorder, for example, the one shown in FIG. 1 is known. This pinch roller is composed of a boss 1 and a rubber roller 2 fitted around the outer periphery of the boss. A hole 11 is formed in the inner surface of the boss 1 for mounting and attaching a rotating support roller for the pinch roller. When the pinch roller is used, that is, when the tape is being fed out, the outer surface 21 of the rubber roller 2
is in pressure contact with a capstan roller (not shown), and the tape is held and fed out between the two, and the outer surface 21 is appropriately shaped to ensure that the tape is held in place during pressure contact with the capstan roller. It is a convex surface with a radius of

By the way, when manufacturing the above-mentioned pinch roller, generally the boss 1 is first formed by casting. Next, a rubber roller 2 having a cylindrical outer surface 21 and an inner surface 22 is made using a mold or the like, and then the rubber roller 2 is fitted into the boss 1. In this state, the outer surface 21 of the rubber roller 2 is polished to make the outer surface 21 a convex surface. - However, since it is necessary to polish the outer surface 21 of the rubber roller 2 to make it convex, it is not possible to reduce the amount of expensive rubber used for the rubber roller 2, and polishing the outer surface 21 is time-consuming. It is not possible to reduce manufacturing costs. Further, because the rubber O-roller 2 is an elastic body, the outer surface 21 cannot be made into a convex surface with high accuracy by polishing, and the accuracy of the pinch roller cannot be improved. Furthermore, there are countless microscopic scratches on the outer surface 21 after polishing, and when the pinch roller is used for a long period of time, the degree of wear on the outer surface 21 varies depending on the part, and the pressure between the pinch roller and the tape increases. It is not possible to increase the above-mentioned accuracy because the difference varies depending on the region. Therefore, it is impossible to reduce the so-called wow and flutter during use, and it is difficult to keep the tape feeding amount constant.

In view of the above-mentioned drawbacks of the conventional pinch rollers, an object of the present invention is to provide a pinch roller and its manufacturing method that can reduce manufacturing costs and improve tape running performance. The gist is to make the contact surface with the rubber roller a convex surface during casting, and to fit the flat rubber onto the boss with the unpolished surface facing up.

The present invention will be described in detail below using embodiments shown in the accompanying drawings.

In the embodiment shown in FIG. 2, a rotary support roller mounting hole 31 is formed in the center of the boss 3, and its outer surface 32 is a convex surface. A flat heald-shaped annular rubber roller 4 is fitted onto the outer surface 62, and its surface is similar to the outer surface 3 of the boss 3.
It is pressed by the convex surface of 2 and becomes a convex surface.

When manufacturing the pinch roller of this embodiment, first, by casting, and if necessary, after casting, the boss 3 is polished.
is made so that its outer surface 32 is a moderately curved convex surface. On the other hand, to make the rubber roller 4, for example, a rubber cylinder of an appropriate thickness is made using a mold or the like. After polishing its surface to a predetermined thickness, it is cut into rounds at appropriate intervals to form a large number of rubber rollers 4. Thereafter, the rubber roller 4 is turned over so that the inner surface that was in contact with the mold is the front side, and the outer polished surface is the back side. When the rubber roller 4 is fitted onto the outer surface 52 of the boss 6, since the outer surface 41 of the rubber roller 4 is the surface that was in contact with the mold, the surface becomes a smooth so-called mold rising surface. The surface 32 of the boss 3 is a highly precise convex surface, and the surface 32 of the boss 3 is a highly precise convex surface.
There is no need to polish the surface 41 of. Of course, if it is not necessary to polish the rubber roller before fitting it onto the boss, the rubber roller may be fitted onto the boss without turning it over.

As described above, according to this invention, the surface of the boss is already a convex surface, so there is no need to polish the outer surface after the rubber roller is fitted, and the amount of rubber used can be reduced, thereby reducing the manufacturing cost of the pinch roller. can be lowered. In addition, the convex surface formed on the outer surface of the rubber roller after it is fitted onto the boss is determined by the convex surface of the boss, and the J convex surface of the boss can be made more precise by casting, etc., so the accuracy of the pinch roller can be increased. In addition, the outer surface of the rubber roller becomes a so-called molded surface, and even when used for a long period of time, the entire surface wears out evenly, making it possible to minimize wow and flutter and keep the amount of tape fed constant. .

[Brief explanation of drawings]

FIG. 1 is a partially sectional plan view showing an example of a conventional pinch roller, and FIG. 2 is a partially sectional plan view showing an embodiment of the present invention. 1.3...Boss 2,4...Rubber roller patent applicant Mizuno Manufacturing Co., Ltd. Patent application agent Patent attorney management Hara - Department No. 1 3132 2 Figure

Claims (1)

[Scope of Claims] 11] The boss (3) is made so that at least the contact portion of the outer surface (32) with the rubber roller is a convex surface in the axial direction, and the rubber roller (4) has a uniform wall thickness. Production of a pinch roller, characterized in that the rubber roller is made so that at least one surface becomes the molded surface, and then the rubber roller is fitted onto the outer surface so that the molded surface becomes the outer surface (41). Method. 12''I A pinch roller comprising a boss (3) whose outer surface (32) is a convex surface and an annular rubber roller (4) of uniform thickness fitted onto the outer surface of the boss.