JPH0626005U - Rotating drum - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a rotary drum capable of preventing damage to a magnetic tape due to a corner of a magnetic input / output section window without impairing input / output characteristics of the magnetic head. [Structure] The magnetic input / output unit 4 of the rotating drum 1 is constructed by implanting a magnetic head 5 in a window 4a formed by forming a rectangular recess in the circumference of the upper drum 1a. A chamfer 6 is formed at the edge of the. After the distance between the edge of the window 4a and the magnetic head 5 is suppressed to a predetermined distance, the corner of the window 4a is cut out to insert the bay 6b.
The chamfered portion 6c is formed on the chamfered portion 6 at the edge of the window 4a extending on both sides of the bay 6b.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotary drum, and more particularly to a rotary drum capable of preventing damage to a magnetic tape due to a corner of a window without impairing input / output characteristics of a magnetic head.

[0002]

[Prior art]

 A rotary drum equipped with a magnetic input / output unit is arranged in a VTR deck or a DAT deck with its axis inclined, and a cylindrical lower drum that guides a magnetic tape and a cylindrical column that is rotatable adjacent to the upper drum. And an upper drum forming the. The upper drum is provided with a magnetic input / output unit for inputting / outputting information to / from a magnetic tape. The magnetic input / output unit moves on the tape surface while coming into contact with the magnetic tape as the upper drum rotates. .

FIG. 4 is a detailed view of a magnetic input / output unit according to a conventional technique, and FIG. 5 is a sectional view taken along line CC of FIG. The magnetic input / output unit 7 is composed of a window 7a having a rectangular recess formed in the upper drum 1a and a magnetic head 5 embedded in the window 7a.

The magnetic tape B travels in the direction indicated by the arrow T while inclining to the rotation surface of the upper drum 1 a indicated by the arrow H and slidingly contacting the upper drum 1 a. When the magnetic input / output unit 7 goes under the magnetic tape B with the rotation of the upper drum 1a, the magnetic tape B is attracted by the vortex in the five windows 7a of the magnetic input / output unit 7, and the magnetic tape B becomes The magnetic head 5 is closely attached.

The edge of the window 7 a forms a chamfer 8 to form a smooth curved surface by buffing, and the chamfer 8 guides the magnetic tape B onto the magnetic head 5 smoothly. However, in the rectangular corner portion of the window 7a, the chamfered curved surfaces of the straight chamfered portions 8 extending on both sides are discontinuously connected, and the concave portions formed in the corners 8b and 8c cannot be buffed. Therefore, fine burr remains without being removed.

Therefore, when the magnetic tape passes through the corners, it may be damaged by residual burr. In particular, a thin tape having a thickness of 9 μm, which is often used for a long time, has a small bending rigidity, is strongly adsorbed in the window 7a due to its flexibility, and may be seriously damaged by residual burrs at the corners. In order to remove the burrs at the corners, a large chamfer 9 that covers the corners can be formed to allow the surface finish.

[0007]

[Problems to be solved by the device]

 However, when the large chamfered portion 9 is formed, the distance between the peripheral edge of the window 7a and the magnetic head 5 is substantially increased by the chamfered dimension, and the tension is extended between the enlarged distances D in FIG. The magnetic tape E that is in a state has a substantially smaller attracting force per area due to an increase in the attracting area, and as a result, in the case of the magnetic tape E having a normal thickness, the inclination angle is shallow. Therefore, it becomes difficult to secure the winding angle θ of the magnetic tape with respect to the magnetic head, and it becomes impossible to obtain a predetermined magnetic input / output characteristic. An object of the present application is to make it possible to remove burrs at the corners of a window while ensuring the above winding angle with respect to the magnetic head.

[0008]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the magnetic input / output section window has a predetermined distance between the edge of the window and the magnetic head, and then the corner of the window is cut out to form a bay entry section. At the same time, chamfers that are continuous in an arc were formed on the chamfers at the edges of the windows extending on both sides of the bay entrance.

[0009]

[Operation] Since the corners of the window can be integrally surface-finished as a series of chamfers, all burrs on the chamfers can be easily removed, and the magnetic tape can By being stretched between the edge of the window and the magnetic head at an inclination angle, the winding angle θ of the magnetic tape with respect to the magnetic head required to obtain a predetermined magnetic input / output characteristic is secured.

[0010]

【Example】

 Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a diagram showing a tape traveling path in a rotary drum type DAT deck. The drum 1 is disposed in the deck with its axis inclined by about 6 degrees, and is provided in the tape path from the supply reel 2a of the cassette 2 to the take-up reel 2b. 3a is a tension regulator, 3b is an inclined post, 3c and 3d are capstans and idlers.

FIG. 2 is a front view of the drum. The drum 1 is composed of a rotatable columnar upper drum 1a and a lower drum 1b which is adjacent to the lower side of the upper drum 1a and guides the tape. The upper drum 1a is provided with a magnetic input / output unit 4, and the magnetic input / output unit 4 relatively moves on the tape surface while coming into contact with the magnetic tape as the upper drum 1a rotates to input / output information. To do. A drum motor 1c drives the upper drum 1a.

FIG. 3 is a detailed front view of the magnetic input / output unit of the rotary drum according to the present invention. A magnetic input / output section 4 is provided on the circumference of the upper drum 1a. The magnetic input / output section 4 has a window 4a formed by opening a recessed portion formed in a rectangular shape, and is planted in the window 4a. And a magnetic head 5. The magnetic head 5 performs magnetic input / output with the magnetic tape B running while slidingly contacting the upper drum 1a, and is arranged at a predetermined distance from the edge of the window 4a.

The corner of the window 4a is cut out to form a bay entry portion 6b. The chamfered portion 6 for guiding the magnetic tape B onto the magnetic head 5 is formed at the edge of the window 4a including the bay entry portion 6b. Is formed over its entire length, and the chamfered portion 6 is finished to be smooth by buffing.

The arcuate chamfered portion 6c of the bay-in portion 6b forms a continuous curved surface with the linear chamfered portion 6 extending on both sides thereof, and the chamfered portion 6 is integrally buffed so as to have a smooth surface continuous with the linear portion. Since it is possible to form a curved surface, it is possible to remove all burrs including the circular chamfered portion 6c of the bayed portion 6b.

The operation of the rotary drum having the above configuration will be described below. The magnetic tape B in FIG. 3 runs in the direction indicated by the arrow T while inclining to the rotation surface of the upper drum 1a indicated by the arrow H and slidingly contacting the upper drum 1a.

When the magnetic input / output section 4 dives under the magnetic tape B as the upper drum 1a rotates, the magnetic tape B is attracted by the vortex flow in the window 4a of the magnetic input / output section 4, thereby causing the window 4a to move. The magnetic tape B is smoothly guided onto the magnetic head 5 by the chamfered portion 6 at the edge of the magnetic tape B, and the magnetic tape B and the magnetic head 5 are brought into close contact with each other.

Since there is a predetermined distance between the edge of the window 4a and the magnetic head 5, the magnetic tape B is stretched between them at a predetermined inclination angle, and the winding angle θ with respect to the magnetic head is secured, so that a predetermined angle is obtained. It is possible to obtain the magnetic input / output characteristics of

The chamfered portion 6 on the periphery of the window 4a has a smooth curved surface without residual burrs, including the arcuate chamfered portion 6c of the indented portion 6b of the corner. Even when the thin tape is strongly attracted to the window 4a, the tape B is smoothly moved between the magnetic head 5 and the chamfered portions 6 and 6c without burrs. .

[0019]

As described above, according to the present invention, the magnetic tape is separated from the edge of the window by keeping the distance between the edge of the magnetic input / output section and the magnetic head at a predetermined distance. Since it is stretched between the magnetic head and the specified inclination angle, the winding angle of the magnetic tape with respect to the magnetic head can be secured, and the bay corner is formed at the corner of the wind to form an arc shape. By forming continuous chamfers, the entire surface of the chamfers can be finished as a series of chamfers, and burrs at all corners can be easily removed.

Therefore, the window of the magnetic input / output unit according to the present invention can prevent damage to the tape when the tape passes through the magnetic input / output unit without impairing the magnetic input / output characteristics.

[Brief description of drawings]

FIG. 1 is a diagram showing a tape traveling path in a rotating drum type DAT deck.

[Figure 2] Overall front view of the drum

FIG. 3 is a detailed front view of a magnetic input / output unit of the rotary drum according to the invention.

FIG. 4 is a view similar to FIG. 3 according to the prior art.

5 is a sectional view taken along the line CC of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotating drum, 1a ... Upper drum, 4 ... Magnetic input / output part, 4a ... Window, 5 ... Magnetic head, 6 ... Chamfer part,
6b ... Bay entry part, 6c ... Chamfer part, B ... Magnetic tape.

Claims (1)

[Scope of utility model registration request] 1. A wind having a recess formed on the circumference of a rotatable columnar upper drum and having a rectangular opening, and a magnetic field which is planted in the window and runs in sliding contact with the upper drum. A magnetic input / output section is formed from a magnetic head for performing magnetic input / output with a tape, and a chamfered section is formed at the edge of the window for guiding the magnetic tape onto the magnetic head of the magnetic input / output section. In the rotating drum, the window of the magnetic input / output section suppresses the edge of the window and the magnetic head to a predetermined distance, and the corner of the window is cut out to form the bay entry section. A rotary drum, characterized in that chamfered portions that extend in an arc shape are formed on the chamfered portions of the edges of the windows extending on both sides of the bay entry portion.