JPS62175955A - Reel base driving device - Google Patents

Abstract

PURPOSE:To execute an oscillating operation whose response of oscillation is quick, and also, whose torque loss is small, by using a magnetic member instead of a frictional sliding member, and executing the oscillating operation by a magnetic attraction. CONSTITUTION:A rotational force which is transferred through a belt 33 by a rotation of a motor rotates a pulley 32, and when the pulley 32 rotates, a gear 34 rotates, and an oscillating arm 38 which is attracted to this gear also turns in the same direction as the rotating direction of the gear 34. Also, a gear 39 is engaged to a supply reel base or a winding reel base, and transfers a rotational force to them. In this regard, in the same way as usual, at the time of fast forward and rewinding, a coupling gear is coupled to both the gears 34, 35, and the gear 34 and the gear 35 rotate as one body. Also, at the time of recording and reproduction, the coupling gear does not work, and the rotational force of the gear 34 is transferred to the gear 35 through what is called a magnet clutch. In such a way, the oscillating arm 38 turns as soon as the gear 34 rotates, and the oscillating is executed at a high response speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a reel stand drive device used in, for example, a video tape recorder.

(Prior Art) In magnetic recording and reproducing devices such as video tape recorders (hereinafter referred to as VTRs), a clutch is built into the reel stand drive device in order to prevent tensilon ripples on the magnetic tape and to keep the tape tensilon value within a tolerance. It is. The magnetic tape is wound by the clutch torque of this clutch during recording and reproduction, and the tape is wound without operating the clutch during fast forwarding and rewinding.

・Here, an example of a conventional reel stand driving device is shown in FIG. (1) is the supply reel stand, (2) is the take-up reel stand, (J
3 is a neck with 9 iso structures. Depending on the rotation direction of this neck S#) mechanism (capstan motor 14 on the side), the neck arm (5), which is a swinging member, rotates in the directions of arrows A and B around the shaft (6), and the tip A gear (7) disposed in the reel unit is configured to mesh with the reel stand f1) or (2).

In addition, (8) is a capstan which is also the rotating shaft of the capstan motor (4), and (9) is this capstan (
8) is a geared pulley that engages with. Further, 01 is a pelt, which transmits the rotation of the pulley (9) to the neck Wb mechanism (J pulley αD (see FIG. 3)).

Next, the swinging mechanism (J) will be explained based on FIG.

FIG. 3 is a sectional view of the neck mechanism shown in FIG. 2. As described above, the belt 11 is wound around the pulley αυ, and the gear U is fitted into the boot 17 (11) so as to be movable only in the direction of the rotation axis (6). In addition, a gear circle independent of the gear (2) is disposed on the top of the gear α2 via a felt (14), and the above-mentioned oscillating arm (
5) is arranged through a felt aperture.

The aforementioned gear (7) is attached to the rotating end of the arm (5).
is disposed, and this gear (7) meshes with gear 0. Note that αe is a spring, and the gears (13 and 0
3 are in pressure contact with each other. Next, the operation of the swinging mechanism (3J will be explained. In the fast forward and rewind modes, the coupling gear αη is coupled with the gears αz and 03 by a mode device (not shown), and the capstan is transmitted to the pulley αB via the belt Ql. The rotational force of the motor (4) is directly transmitted to the gear fi:IK.

The gear (7) is rotated by the rotation of the first gear, and the oscillating arm (5) is connected to the gear α east and the felt a.
Due to the frictional force with Convey that rotational force.

In the recording/reproduction mode, the gear ση is not connected and the pulley α1)
The rotational force is transferred to the reel stand (
1) and (2) are driven so that the tape tension limit value falls within an appropriate value.

FIG. 4 shows another conventional example of the neck AB mechanism. This is a felt α (to) arm (1) instead of felt α9.
It is placed between the gear (7) and the arm (a1), and the gear (7) and the arm a1 are pressed against each other by a spring (2).The operation is the same as that shown in FIG.

There are problems with the neck S-shape mechanism described above. In other words, the response speed of the swing is slow due to the frictional force of the reel stand +11. (2+
It takes time to drive the rotation, and a similar time lag occurs when switching modes. On the other hand, K, which speeds up the response, requires an increase in frictional force. However, this increases the lack of driving force i.

(Problems to be solved by the invention) In the conventional reel stand drive device, the response speed of the neck 4H is slow.
The problem was that there was a loss of driving force.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a reel stand drive device that has a quick response to a swinging motion and wastes less driving power.

[Structure of the invention]

(Means for Solving the Problems) The present invention uses a K11a member instead of a frictional sliding member, and performs the neck WD operation with one magnetic attraction force.

(Function) With the above configuration, the swinging member swings with less time lag, and rotational force is transmitted to the reel stand faster than before.

(Embodiment of the Invention) An embodiment of the reel stand driving device according to the present invention will be described below with reference to FIG. FIG. 1 is a sectional view showing the above embodiment. However, only the oscillating mechanism is discussed, and the capstan motor and other components are omitted because they are the same as in the conventional example.

Here, (30) is a chassis, on which a shaft Gυ is disposed, and the pulley '32 is rotatably fitted to this shaft 01)K. Note that (to) is a belt to which rotational force from a motor (not shown) is transmitted. A gear (b) is press-fitted into the pulley (to), and rotates together with the pulley (to). A gear (to) is disposed above the gear (b), and is rotatable independently of the pulley (to) and the gear (b). A soft magnetic material such as an iron plate is embedded in the surface of the gear (to) that faces the gear 6, and the gear (to) is
) is a gear (
The rotational force is transmitted from (b) through a magnetic clutch mechanism. Note that a shield plate 07) is provided on the lower surface of the gear I3a. The iron is a swinging arm that is a swinging member, which is made of a soft magnetic material such as an iron plate, and is attracted to the lower surface of a gear (b) made of a hard magnetic material. . A gear 61, which is a second rotating member, is disposed at the rotating end of the oscillating arm (to) that rotates around an axis c31).
The operation of the above-mentioned device which meshes with the gear in the upper stage will be explained below. The rotational force transmitted through the belt (to) due to the rotation of a motor (not shown) rotates the pulley c35. When the Boo IJ C3'IJ rotates, the gear C34) rotates, and the oscillating arm (to) that is attracted to it also rotates in the same direction as the rotation direction of the gear (to). It meshes with the half supply reel stand or the additional reel stand and transmits rotational force to them. In addition, in the same way as before, when fast forwarding and rewinding, the coupling gear (similar to αη in Figure 3) is coupled to both gears (B) and (C), and gear (B) and gear (To) are integrated. Rotate. Also, during recording and reproduction, the combined gear does not work, and the gear (to) is connected to the gear (b) via a so-called magnetic clutch.
rotational force is transmitted.

As described above, the swing arm (to) immediately rotates with the rotation of the gear (b). Therefore, a swinging motion with a quick response speed can be performed. In addition, in the above embodiment, the gear (b)
Although the structure is such that the oscillating arm and the oscillating arm are in direct contact with each other, it is not necessary to do so, and there may be a gap formed by a spacer or the like between the two. The Saratrap swinging arm may be made of a hard magnetic material.

(Effects of the Invention) As described above, according to the present invention, it is possible to perform a swinging operation with quick response and less torque loss.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the reel stand driving device according to the present invention, FIG. 2 is a plan view showing an example of a conventional reel stand driving device, and FIG. A sectional view showing one example, and FIG. 4 is a sectional view showing another conventional example. (9)...chassis, 32-way pulley, mountain belt, word...rotating magnetic member, a, 39...gear, a...
・・Magnetic plate, 謔・・Swinging arm. Agent Patent Attorney Noriyuki Chika 111 5t-. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] A rotating magnetic member rotatably supported on a chassis between a supply reel stand and a take-up reel stand and to which rotational force from a motor is transmitted via a rotation transmission mechanism; a first rotating member to which the rotational force of the rotating magnetic member is transmitted via a magnetic clutch mechanism; and a neck that is arranged to be rotatable coaxially with the rotating magnetic member and is magnetically attracted to the rotating magnetic member. a swinging member; and a swinging member rotatably supported by the rotating end of the swinging member, engaged with the first engagement member, and engaged with the supply or take-up reel stand when the swinging member swings. A reel stand driving device comprising: a second rotating member capable of transmitting the rotational force of the first rotating member;