JPH0353711B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic tape device such as a tape recorder, a video tape recorder, etc., in which the reel engages with and rotates integrally with a reel on the side that supplies magnetic tape in a cassette. The present invention relates to a load torque applying device that applies load torque to a reel stand.

Conventional Structures and Problems Many of the recent tape recorders and video tape recorders have a fast-forward mode for transferring the magnetic tape from the supply reel to the take-up reel at high speed. In this fast-forward mode, it is known that it is important to apply an appropriate load to the supply reel stand and provide appropriate back tension to the magnetic tape running at high speed in order to protect the magnetic tape. In other words, if this back tension is not present, the magnetic tape will be wound abnormally loosely when it is wound onto the take-up reel, causing it to be wound with partial deformation or damage to the tape edges. On the other hand, if the buck tension becomes abnormally high, accidents such as permanent elongation of the magnetic tape or the inability to wind it onto the take-up reel may occur. become. Therefore, conventionally, in order to apply an appropriate load to the supply reel stand, a brake means that can come into contact with and separate from the supply reel stand is specially provided, and a dedicated solenoid is provided for the operation of this brake means. Also, in a so-called power drive type device in which the operating mode is switched by a motor, an operating member such as a drive lever for operating the brake means is required. Although this configuration meets the purpose of applying an appropriate load to the supply reel, it has problems such as increasing the number of parts, complicating the mechanism, increasing weight, increasing power consumption, and increasing costs. It had a point.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and particularly includes a first position where the tension of the magnetic tape can be detected when the magnetic tape is pulled out from the cassette;
It has a tension arm arranged so as to be able to reciprocate between a second position corresponding to the state in which the magnetic tape is housed in the cassette, and when the tension arm is in the second position, the supply The object of the present invention is to obtain a device for applying a load torque to a supply reel stand, which is conveniently applied to a magnetic tape device configured to transfer a magnetic tape from a reel to a take-up reel at high speed, and can achieve stable tape running with a simple configuration. do.

Structure of the Invention In order to achieve the above object, the load torque applying device of the present invention includes a reel stand that engages with and rotates integrally with a reel on the side that supplies the magnetic tape inside the cassette, and a reel that rotates integrally with the reel that supplies the magnetic tape outside the cassette. a tension arm capable of reciprocating between a first position where the tension can be detected and a second position corresponding to the state in which the magnetic tape is housed in the cassette; a tension band that interlocks with the tension arm so as to apply a load torque to the reel stand when the tension arm is in the second position; This configuration includes a tension band pressing means that applies load torque to the reel stand by pressing through an elastic member in conjunction with the tension arm.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

1 to 3, the tension arm 2 is rotated counterclockwise around the shaft 1 by the spring 14, and the tension arm 2 is attached to the tension band 4 wound around the supply reel stand 3. It is connected to one end, and applies a load to the supply reel stand 3 by the tension of the spring 14. Said tension band 4
is made by bonding a friction member 6 such as felt to a flexible metal strip 5, the other end of which is fixed to a shaft 17 implanted in a fixed substrate (not shown), and the friction member 6 is In a form that surrounds the outer periphery of the supply reel stand 3,
One end portion of the band-shaped metal plate 5 is fixed to a tension band attachment member 8. This tension band attachment member 8 consists of a first arm 9 and a second arm 10, and the first arm 9 is connected to the second arm 1.
The shaft 10a is rotatably fitted to the shaft 10a at one end of the shaft 10a. A torsion spring 11 is attached to these arms 9 and 10.
is suspended, and as shown by arrows in FIG. 3, a force is applied to both arms 9 and 10 that tends to separate them from each other. However, since the locking portion 9b, which is provided integrally with the first arm 9, comes into contact with a part of the second arm 10, the second arm 10 is prevented from being separated by more than a predetermined angle. Further, the first arm 9 has a peak portion 9a that can come into contact with a part of the tension arm 2, and the second arm 10 has a band-shaped metal plate 5 fixed thereto and comes into contact with this band-shaped metal plate 5. The shaft 10b is loosely fitted into the hole 12, so that it is rotatably attached to the tension arm 2, and constitutes tension band pressing means.

FIG. 1 shows a state in which the tension arm 2 controls the back tension of the magnetic tape 15 pulled out of a cassette (not shown). That is, in FIG. 1, as the magnetic tape 15 is pulled out from the cassette, the tension arm 2 is rotated counterclockwise about the shaft 1 by the tension of the spring 14, and the tension band 4
3 shows a state in which a load torque is applied to the supply reel stand 3 serving as the supply side of the magnetic tape 15. Hereinafter, the position of the tension arm 2 in this state will be referred to as a first position. Here, a magnetic tape 15 pulled out from a cassette is hung on a tape tension detection pin 13 installed at the tip of the tension arm 2. In this state, when the back tension of the magnetic tape 15 increases, the tension arm 2 is rotated clockwise about the shaft 1. Then, the tension band attachment member 8 provided on the tension arm 2 moves in a direction (to the right in FIG. 1) to loosen the winding force of the tension band 4 wound around the supply reel stand 3. As a result, the load torque on the supply reel stand 3 is lowered, and the back tension of the magnetic tape 15 is reduced.

Next, when the magnetic tape 15 is stored in a cassette (not shown), the tension arm 2 is rotated by a suitable rotation mechanism (not shown) such as a lever, as shown in FIG. Therefore, it is held at a position in which it is largely rotated clockwise about shaft 1 (hereinafter referred to as the second position). In this state, in conventional devices, the tension band 4 is generally loosened and held in a state separated from the supply reel stand 3 by appropriate means, but in this embodiment, the tension band 4 is A tension band pressing means constituted by a tension band attaching member 8 fixing one end of the strip metal plate 5 of No. 4 regulates the form of the strip metal plate 5, and allows the strip metal plate 5 to be placed in an appropriate manner on the supply reel stand 3. Load torque is applied, and at the same time, unnecessary sagging of the tension band 4 is prevented. That is, while the tension arm 2 rotates clockwise, the first arm 9
and at the same time the second arm 10
rotates integrally with the tension arm 2 while pressing the tension band 4 via the torsion spring 11. Then, the tension arm 2
When rotated to the second position shown in the figure, it is pressed against the tension arm 2. 1st arm 9
deforms the torsion spring 11, and the second arm 10 is pressed by the elastic force corresponding to this deformation, so that the tension band 4, which is being pressed by the second arm 10, absorbs the slack and furthermore It is wound around the supply reel stand 3 with a winding force of . As a result, an appropriate load torque is applied to the supply reel stand 3.
At this time, the band-shaped metal plate 5 is smoothly bent along the curved surface portion 10a of the second arm 10. In addition, the cylindrical portion of the supply reel stand 3 around which the tension band 4 is wound generally stabilizes the coefficient of friction between the friction member 6 and the cylindrical portion against life and environment.
In order to stabilize the tension, a plurality of grooves (not shown) are cut in the circumferential direction, and these measures also contribute to stabilizing the load torque by the load torque applying means in this embodiment. .

Effects of the Invention As explained above, according to the present invention, with an extremely simple structure, it is possible to stably apply an appropriate load to the supply reel stand when a magnetic tape is stored in a cassette. By applying appropriate back tension to the magnetic tape when the magnetic tape is transferred from the supply reel to the take-up reel in this state, damage to the tape can be prevented and stable tape running can be realized. In addition, since the load torque on the supply reel table can be controlled simply by the movement of the tension lever, there is no need for a special solenoid, brake member, or drive member to drive and control these, which greatly contributes to making the device smaller and lighter. It is possible. Furthermore, since unnecessary slack in the tension band can be absorbed, contact between various parts near the tension band and the tension band can be prevented, and damage to parts including the tension band can be prevented.

[Brief explanation of drawings]

Fig. 1 is a plan view of a load torque applying device according to an embodiment of the present invention with the magnetic tape pulled out of the cassette, and Fig. 2 is a plan view of the same device with the magnetic tape housed in the cassette. , FIG. 3 is a perspective view of the tension band pressing means provided in the device. DESCRIPTION OF SYMBOLS 1... Axis, 2... Tension arm, 3... Supply reel stand, 4... Tension band, 5... Band-shaped metal plate,
6...Friction member, 8...Tension band mounting member,
9... First arm, 10... Second arm, 11... Torsion spring, 13... Tape tension detection pin, 14
...Spring, 15...Magnetic tape.

Claims (1)

[Claims] 1. A reel stand that engages with and rotates integrally with the reel that supplies the magnetic tape in the cassette, a first position that can detect the tension of the magnetic tape outside the cassette, and a tension arm capable of reciprocating between a second position corresponding to a stored state; and a tension arm configured to apply a load torque to the reel stand when the tension arm is in the first position. a tension band interlocking with the tension arm; and when the tension arm is in the second position, a part of the tension band is pressed via an elastic member in interlock with the tension arm, thereby reeling the reel. A load torque applying device comprising a tension band pressing means for applying a load torque to a table.