JPS62154254A - Rotary head assembly for magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To easily release a fixed cylinder from a metallic mold so that the cylinder having dimensional and profile accuracy can be mass-produced inexpensively in a short time, by forming the cylindrical part and leading part as separate members. CONSTITUTION:A cylindrical part 301A and leading part 303A are formed as separate members and they are assembled afterward. When this fixed cylinder is formed by machining, a considerable time and working cost are spent in order to obtain prescribed dimensional and profile accuracy and, when the fixing cylinder is manufactured by integral forming, it is difficult to release the formed cylinder from a metallic mold and problems of frequent occurrence of damage of the end face part of the leading groove and improper accuracy also exit. When the above-mentioned manufacturing process is adopted, however, a fixed cylinder having prescribed dimensional and profile accuracy can be mass-produced inexpensively in a short time and the cylindrical part 301A and leading part 303A can be formed individually by using material suitable for their functions.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to improvements in rotary head assemblies for magnetic recording and reproducing devices, such as video tape recorders, and in particular to fixed cylinders thereof.

[Conventional technology]

A rotary head assembly of a conventional magnetic recording/reproducing apparatus is constructed as shown in a perspective view in FIG. 4 and a sectional view in FIG. 5.

That is, in the figure, (1) is a recording/reproducing head for recording and reproducing information on a tape-shaped recording medium (magnetic tape) (6) such as a video tape, and is attached to a rotating cylinder (2). (3) is a fixed cylinder equipped with a bearing mechanism (4) that supports the rotary cylinder (2), and has a cylindrical portion on the outer peripheral surface that faces the inward surface of the tape-shaped recording medium (6) and guides its running. (301) and tape-shaped recording medium (6)
It has an IJ-shaped part (303) which forms a lead groove (302) that opposes the edge of the rotary cylinder (2) and regulates the position of the rotary cylinder (2) in the axial direction when it is traveling. (5) is a rotating shaft (the force is applied by a 7-lunge fixed to the shaft (5), and the rotating cylinder (2) is fixed to the 7-lunge (7) by suitable means such as a screw (8). There is.

Next, the operation will be explained. Rotated by electric motor 11t
When you rotate ll (5), the 7 lunge (
7) through which the rotating cylinder (2) rotates. And a recording/reproducing head (1) attached to a rotating cylinder (2)
However, the lead m (302) formed in the constant cylinder (3)
), a recording signal is recorded on a tape-shaped recording medium (6) that moves, or an already recorded recording signal is reproduced. Incidentally, in order to reduce the friction between the tape-shaped recording medium (6) running on the outer peripheral surface of the fixed cylinder (3) and the fixed cylinder (3), the surface of the fixed cylinder (3) is treated with sink marks. The end face of the lead part (303) that guides the tape-shaped recording medium (6) prevents buckling of the tape-shaped recording medium (6) and prevents the tape-shaped recording medium (6) and the lead part (303) from buckling. An undercut is provided to prevent wear on the end face, that is, the lead groove (302).

[Problem that the invention seeks to solve]

Conventional magnetic recording and reproducing devices are configured as described above, so when forming the fixed cylinder by cutting, it takes a lot of time to process to the specified precision, the processing cost is high, and When forming a fixed cylinder by molding, it is difficult to release the mold, leading to damage to the end surface of the lead groove,
There were problems such as frequent errors in accuracy.

This invention was made to solve the above-mentioned problems, and provides a rotary head for a magnetic recording/reproducing device that can mold a fixed cylinder in a short time, at low cost, and with predetermined dimensional and shape accuracy. Provide assembly, S
The purpose is to

[Means for solving problems]

In the rotary head assembly of the magnetic recording/reproducing apparatus according to the present invention, the cylindrical portion of the fixed cylinder and the lead portion are formed as separate members.

[Effect]

In the fixed cylinder of this invention, the cylindrical part and the lead part are formed as separate members; this makes it possible to form the fixed cylinder while ensuring the specified dimensional accuracy and shape accuracy, and further reduces the processing time of the fixed cylinder. can do.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. FIG. 1 is a longitudinal cross-sectional view of a rotary head assembly of a magnetic recording/reproducing device, and FIG. 2 is an exploded perspective view of a fixed cylinder in the embodiment shown in FIG. The explanation will be omitted.

In the figure, (3A) is the fixed cylinder corresponding to (3) of the conventional type, and (301A) is the fixed cylinder corresponding to (301) of the conventional type.
The cylindrical part (303A) corresponding to the lead part (303A) is a lead part, which is molded as a separate member.
03A) rotates the tape-shaped recording medium (6) into the rotating cylinder (3).
A) is formed in an arc shape within a range (usually 180° or less) that is restricted in the axial direction, and a recess (304) into which the lead part (303A) is fitted is formed in the cylindrical part (3oIA). By fitting the cylindrical part (301A) into the recess (304), the cylindrical part (301A) can be easily positioned, and the lead tt4 (
302).

In this way, the cylindrical part (301A) and the lead part (303A)
By forming the parts as separate parts and combining them, it takes a lot of time and processing cost to finish to the specified dimensional accuracy and shape accuracy when forming by cutting as in the past. Also, the cylindrical part (301A) and the lead part (30
When integrally molding 3A) and 5), there were problems such as difficulty in releasing the mold, frequent occurrence of metal loss at the end of the lead groove, and poor precision. It becomes possible to form a large quantity of fixed cylinders in a short time and safely. In addition, the cylindrical part (301A) and the lead part (30
3A) and 3A) can be individually formed from materials suitable for each function. For example, the lead portion (303A) that comes into contact with the edge of the tape-shaped recording medium (6) is molded from fine ceramics with excellent wear resistance, and the cylindrical portion (303A)
01A) can be molded from wear-resistant plastic, which is cheaper and easier to mold than fine ceramics.

Another embodiment of the invention is shown in FIG. In the figure, (3B) is a fixed cylinder, (301B) is a cylindrical part,
(303B) is a lead part, and this embodiment is different from the embodiments shown in FIGS.
1B) has a constant diameter over its entire axial length, and the lead portion (303B) is formed into a cylindrical shape, and this embodiment has the advantage that the cylindrical portion (301B) can be easily formed. The lead portion (303B) can be fitted into the cylindrical portion (301B) by any suitable means such as press fitting or adhesive.

Note that this invention is not limited to the above embodiments,
For example, the lead portion may be formed in a cylindrical shape, and a recess into which the lead portion is fitted may be provided in the cylindrical portion, or the diameter of the cylindrical portion may be made uniform over its entire axial length, and the lead portion may be formed in the axial direction of the tape-shaped recording medium. It is also possible to form the guide to a size necessary for the guide and fix it to the outer circumferential surface of the cylindrical portion by adhesive or other suitable means.

〔Effect of the invention〕

As described above, in this invention, the cylindrical part and the lead part of the fixed cylinder are formed as separate members, so that when molding these parts, it is easy to release the mold from the mold, υ, and the lead part has a predetermined size. It is possible to mass-produce fixed cylinders with shape accuracy in a short time and at low cost.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of the present invention, and FIG.
FIG. 3 is an exploded perspective view of the identification cylinder in the embodiment shown in the figure, FIG. 3 is an exploded perspective view of another embodiment of the present invention, FIG. FIG. In the figure, (1) is a recording/reproducing head, (2) is a rotating cylinder, (3A) and (3B) are fixed cylinders, and (301) is a rotating cylinder.
A), (301B) is the cylindrical part, (303A). (303B) is a lead portion, and (304) is a recess. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent: Patent Attorney Masuo Oiwa 303B+
- Part of the procedural amendment in Figure 4 (voluntary) 2. Name of the invention Rotating head assembly for magnetic recording and reproducing device 3. Relationship with the person making the amendment Patent applicant address 2-chome, Marunouchi, J1-ku, Chiyo, Tokyo No. 3 Name (601) Mitsubishi Electric Corporation Address
Mitsubishi Electric Corporation, 2-2-3 Marunouchi, Chiyoda-ku, Tokyo /tsu,:he'1- ゝName (7375) Patent Attorney Masu Oiwa 11i1, -1゛,1
．．・' 5. Detailed explanation of the invention column 6 of the specification to be amended, contents of the amendment (1) In the specification, page 6, line 14, "Cylindrical part (301A) -
Correct the statement to [Lead section (303A) J. that's all

Claims (6)

[Claims] (1) A rotating cylinder that holds a recording/reproducing head, a cylindrical part that rotatably supports the rotating cylinder and guides its travel by facing the inward surface of the tape-shaped recording medium, and a cylindrical part that faces the edge of the tape-shaped recording medium. A rotary head assembly for a magnetic recording/reproducing device including a fixed cylinder having a lead portion for regulating the axial position of the rotating cylinder during travel, characterized in that the cylindrical portion and the lead portion are formed as separate members. Rotating head assembly for magnetic recording and reproducing equipment. (2) A rotary head assembly for a magnetic recording/reproducing device according to claim 1, wherein a recess into which a lead portion is fitted is formed in the cylindrical portion. (3) A rotary head assembly for a magnetic recording/reproducing device according to claim 1, wherein the cylindrical portion has a constant diameter in the axial direction. (4) Claim 1 in which the lead portion is provided only in a range that restricts the tape-shaped recording medium in the axial direction of the rotating cylinder.
A rotary head assembly for a magnetic recording/reproducing device according to items 1 to 3. (5) Claim 1 in which the lead portion is formed into a cylindrical shape
A rotary head assembly for a magnetic recording/reproducing device according to items 1 to 3. (6) A rotary head assembly for a magnetic recording/reproducing device according to any one of claims 1 to 5, wherein the cylindrical part is made of wear-resistant plastic and the lead part is made of fine ceramics.