JPS6313266B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a tape guide roller for highly accurate running of a magnetic tape in a video tape recorder or the like.

Conventional configuration and its problems The tape in the vicinity of a rotating cylinder in a video tape recorder is configured to run as shown in FIG.

In Fig. 1, 1 is the lower cylinder, which is fixed to the deck and has helical steps on its cylindrical surface.
The lower end of the tape 4 is guided by the edge 3 of the step,
A magnetic tape 4 is wound helically on the lower cylinder 1 and runs. An upper cylinder 5 rotates coaxially with the lower cylinder 1, has a magnetic head attached thereto, and records and reproduces signals on the magnetic tape 4. Reference numeral 6 denotes a fixed shaft, which, together with an adjacent tape guide roller 7, regulates the running direction and angle of the tape 4. Since it is necessary to lower the tension of the tape 4 as much as possible, a cylinder is inserted into the shaft of the tape guide roller 7, and the cylinder moves and rotates together with the tape 4, so that the tape 4 is not subjected to significant friction.

Further, the lower end of the tape 4 is guided by the edge 3 of the step of the lower cylinder 3 as described above, but in order to regulate the position of the upper end, the tape guide roller 7 is provided with a collar 7' on the shaft. The upper end of the tape touches the inner surface of the brim as it runs.

In the tape guide roller 7, if there is wobbling in the rotating cylinder, the running of the tape 4 will be uneven, so the rotational accuracy must be several microns or less.

FIG. 2 shows a conventional example of the tape guide roller 7. 8 is a shaft into which a resin cylinder 9 is inserted;
A magnetic tape is in contact with the outer surface 10 of the cylinder 9. Cylinder 9
rotates as the tape runs so that the outer surface 10 has the same linear velocity as the tape running speed. Lubricity during rotation is maintained by the resin forming the cylinder 9. Further, a collar 11 is press-fitted into the shaft 8, and the upper end of the magnetic tape comes into contact with the lower surface 12 of the collar 11, thereby regulating the tape position. Further, a collar 13 is press-fitted into the shaft 8 to prevent the cylinder 10 from falling off, and a screw 14 is provided at the other end of the collar 13 to fix it to a deck.

In such a configuration, it is difficult to process the cylinder 9 with high precision, and the concentricity of the inner surface 15 and the outer surface 10 of the cylinder 9 in contact with the axis 8 may be out of alignment, or the straightness (curvature) of the entire cylinder 9 may be out of alignment. , the inner surface 15 tends to be out of roundness, making it difficult to rotate the cylinder 9 with high precision.

Purpose of the invention The present invention solves the above-mentioned drawbacks.
It provides a high-precision tape guide roller and realizes a video tape recorder with good image quality.

Structure of the Invention The present invention includes two opposing collars having bearings at one end that are in contact with the outer periphery of the pipe and supporting the rotation of the pipe, and the collars having a gap with the hole in the pipe and passing through the pipe. It is configured to be connected by a shaft.

Description of examples Examples of the present invention will be described in detail below.

In FIG. 3, 17 is a pipe made of a lubricating material such as Teflon, and has an outer surface 17'.
has sufficient roundness and cylindricity (for example, several μm or less)
It is processed by means such as turning and centerless grinding to have a Of course, the secondary processing may be omitted by a method such as extrusion. The hole 17'' of the pipe 17 does not require special precision. Reference numeral 18 denotes a collar, and at one end of the collar 18 there is a bearing portion 19 that is in contact with the outer surface 17' of the pipe 17 and supports the rotation of the pipe 17. The bearing part 19 has a good finished surface roughness by turning. Two collars 18 are provided for one tape guide roller, and they face each other and have a mounting screw 20 at one end for mounting on the deck. Press-fitted into shaft 21. Shaft 2
1 passes through the hole 17'' of the pipe 17, but there is a sufficient gap between the shaft 21 and the hole 17'' and they do not touch each other. Therefore, pipe 17
Only its outer surface 17' contacts the bearing portion 19 of the collar to rotate. Further, the widthwise position of the tape is regulated by the end face 22 of the brim.

Effects of the Invention As described above, the present invention has two opposing collars each having a bearing at one end that is in contact with the outer periphery of a pipe to support the rotation of the pipe, and a shaft that passes through the pipe with a clearance therebetween. This is a tape guide roller with two flanges attached, and since the outer circumferential surface of the roller is in contact with the bearing, there is no influence of outer circumferential wobbling due to the concentricity of the outer circumference of the cylinder and the hole as in conventional examples, and the inner surface of the hole Any deviation or fluctuation in the degree of vacuum will not affect the performance at all. Therefore, it is only necessary to finish the outer surface 17'' of the cylinder 17 with high precision;
7" is easy to process with high accuracy, mass production is possible, and it can be carried out at low cost. Also, the bearing part 19 of the collar 18 does not require very high precision. The reason is that the outer circumference 17'
The magnetic tape is in contact with the magnetic tape, and since the magnetic tape is given tension and runs at a certain position, the outer surface 17' of the shaft and the bearing part 19 always maintain contact only at a certain point. The bearing portion 19 does not require high precision over its entire circumference.

As described above, the tape guide roller according to the present invention can easily realize highly accurate rotation of the roller, and stable running and regulation of the tape can be carried out, thereby making it possible to obtain a video tape recorder with good image quality.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a schematic configuration of the vicinity of a cylinder of a video tape recorder, FIG. 2 is a sectional view of a conventional tape guide roller, and FIG. 3 is a sectional view of a tape guide roller in an embodiment of the present invention. . 17...Pipe, 18...Brim, 19...Bearing section, 21...Shaft.

Claims (1)

[Claims] 1. Arranging two opposing collars that are in contact with the outer periphery of the pipe and have a bearing at one end that supports the rotation of the pipe, and that the two collars have a clearance with respect to the hole in the pipe, and the pipe is 1. A tape guide roller, characterized in that the tape guide roller is connected by a penetrating shaft, and has an attachment portion to a substrate provided at one end of the shaft.