JPS62208448A - Tape tension controller - Google Patents

Abstract

PURPOSE:To make an equipment small in size and light in weight, and to realize low power consumption by drawing elastically and energizing a tension band detaining member so that tension roughly equal to the tension applied to one of a tension band by action of a tension arm is operated on the other of the tension band. CONSTITUTION:Frictional force operated on a tension band 14 by rotation of a reel turntable 1 becomes a direction as indicated with an arrow, and tension F2 of the tension band applied to an end part 14a of the tension band 14 becomes drawing-side tension, therefore, becomes larger than tensile force F2 applied to the tension band by action of a tension spring 21. As a result, a tension band detaining member 16 turns clockwise against the tensile force of the tension spring 21 around a shaft 15, loosens the tension band 14, and also, decreases a winding angle to the reel turntable 1. Accordingly, damping force applied to the reel turntable 1 by the tension band 14 is decreased, and driving torque of the reel turntable 1, which is required for rewinding a magnetic tape 3 is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is directed to a tape tension control device conveniently used in video and sound field equipment such as a VTR.

[Conventional technology]

FIG. 3 is a plan view showing a conventional tape tension control device. In the figure, 1 is a reel stand rotatably attached to a base (not shown), 2 is a reel that rotates integrally with the reel stand 1, 3 is a magnetic tape wound on the reel 2, 4a, 4b 5 is a tape guide, 5 is a shaft implanted in the base, 6 is a tension arm rotatably attached around the shaft 5, 7 is a tension ball implanted in the tension arm 6, and 8 is a tension arm. 6 is an implanted shaft, 9 is a spring hook provided on the tension arm 6, 1 is
0 is a spring hook provided on the base, 11 is a spring hook 9.
A tension band locking member is fixed to the base by a tension spring applied between 10 and a tension band locking member 14 is wound around the reel stand l, one end is rotatably locked to the shaft 8, and the other This is a tension band whose end is fixed to a tension band locking member ν.

Next, the operation will be explained. In other words, the magnetic tape 3 wound on the reel 2 is guided by the first tape guide 4a, joined to the tension ball 7, and then connected to the second tape guide 4.
It is guided by b and pulled out.

In audiovisual equipment such as a VTR, it is necessary to control the tape tension within a certain range when the magnetic tape 3 is pulled out from the reel 2.
The braking force applied to the reel stand 1 by the tension arm 6 is amended by the tension arm 6. By the way, if the tape tension decreases for some reason, such as when the winding diameter of the magnetic tape 3 wound on the reel 2 is large, the tape guides 4a and 4
The balance of forces between the magnetic tape 3 and the tension ball 7, which are sandwiched between Since the tension band 14 is rotated and pulled, the braking force applied to the reel stand 1 by the tension band 14 increases, and the tape tension when pulling out the magnetic tape 3 from the reel 2 increases. On the contrary, reel 2
If the tape tension increases for some reason, such as when the winding diameter of the magnetic tape 3 is small, the tension ball 7 is pushed back by the tension of the magnetic 95 tape 3 between the tape guides 4a and 4b, and the tension arm 6 The tension band 14 rotates counterclockwise around the shaft 5.
As a result, the braking force applied to the reel stand 1 by the tension band 14 is reduced, and the tape tension when pulling out the magnetic tape 3 from the reel 2 is reduced.

As described above, the tape tension when the magnetic tape 3 is pulled out from the reel 2 is controlled so that it always falls within a certain range.

[Problem that the invention seeks to solve]

Conventional tape tension control devices are configured as described above, so when a magnetic tape is wound onto a reel by the rewinding operation of a VTR, etc., the frictional force applied to the tension band by the rotation of the reel stand tightens the tension band. This causes excessive braking force to be applied to the reel stand, which increases the reel stand drive torque required for rewinding and requires a large reel stand drive motor, etc.
This poses a problem in that it impedes efforts to make devices smaller, lighter, and consume less power.

This invention was made to solve the above-mentioned problems, and it prevents the braking force applied to the reel stand from increasing unnecessarily during the rewinding operation, and reduces the reel stand drive torque required for one rewind. The object of the present invention is to obtain a tape tension control device that enables the use of a small reel stand drive motor by lowering the tension, thereby making the device smaller, lighter, and lower in power consumption.

[Means for solving problems]

The tape tension control device according to the present invention movably locks one end of the tension band to the base via the tension band locking member, and applies a tension in the opposite direction that is approximately equal to the tension applied to the tension band by the tension arm. The tension band locking member is biased by a spring or the like toward a stopper provided on the base so as to apply a force to the tension band.

[Effect]

The tension band locking member in this invention moves in the direction of loosening the tension band without applying any external operating force due to the tension band tension increased by the frictional force between the reel stand and the tension band during the rewinding operation, and the tension band This reduces the braking force applied to the reel stand and reduces the reel stand drive torque required for rewinding.

〔Example〕

1 and 2 showing one embodiment of the present invention will be explained below. That is, in the figure, reference numerals 1 to 11 and 14 are exactly the same as those in the conventional example shown in FIG. 8, so their explanation will be omitted. 15 is a shaft planted in the base,
16 is a tension band locking member rotatably attached to the shaft 15, 17 is a spring hook provided on the tension band locking member 16, 1 is a spring hook installed in the base, and 19 is a spring hook installed in the base. The stopper is planted in the tension band locking member 16, and the tension band-4
The end 14b of the tension band 14 is attached to the end 14b of the tension band 14 by the tension arm 64 rule, i2 digit spring 11, which is a tension spring applied between the spring hook 17 and the second eye. The tensile force applied to ? +If it melts, the equal tensile force F is applied to the end of the tension band￥AS1
4a, the tension band locking member 16 is urged toward the stopper 19 with the shaft 15 as a fulcrum.

By the way, when the magnetic tape 3 is pulled out from the reel 2, the rotation of the reel stand 1 causes the tension band 14 to be pulled out.
The frictional force acting on the tension band 14 is in the direction of the arrow shown in FIG. becomes smaller than As a result, the tension band locking member 16 is reliably held in contact with the stopper 19 by the tensile force of the spring 21. Regarding the tape tension control operation, please refer to the third
Since it is completely the same as the conventional example shown in the figure, the explanation will be omitted.

Next, when winding the magnetic tape 3 onto the reel 2 by a rewinding operation, the frictional force acting on the tension band 14 due to the rotation of the reel stand 1 is in the direction of the arrow shown in Figure @2, and the end 14a of the tension band 14 is The tension It's of the tension band 14 applied to is the tension side tension, so
This is greater than the tensile force applied to the tension band 14 by the action of the tension spring 21. As a result, the tension band locking member 16 rotates clockwise around the shaft (2) against the tensile force of the tension spring 21 without applying any external operating force, tightening the tension band 14 and tightening the tension band. 14 around the reel stand 1 reduces the angle. Therefore, the tension band 14
As a result, the braking force applied to the reel stand 1 is reduced, and the reel stand 1 necessary for rewinding the magnetic tape 3 is reduced.
The driving torque of will be reduced.

In the above embodiment, the tension band locking member 16 rotates around the shaft, but the tension band locking member 16 may be driven linearly or curved, and further Band locking member 16
As the biasing means, the tension spring 2 shown in the above embodiment is used.
A torsion spring or the like may be used instead of 1. Note that the shaft, splash slide, and stopper 19 do not need to be installed directly on the base (they may be attached to other members.Also, in the above embodiment, the case of magnetic tape was explained. The present invention may be a device that handles elongated strip-shaped objects such as optical films, threads, etc., and the same effects as those of the above embodiments can be achieved.

〔Effect of the invention〕

As described above, according to the present invention, one end of the tension band is biased toward the stopper with a tensile force that is approximately equal to the tensile force applied to the other end of the tension band by the tension arm. Therefore, the reel stand drive torque required during rewinding is reduced, a small reel stand drive motor can be used, and the device can be made smaller, lighter, and consume less power.

[Brief explanation of drawings]

Fig. 1 is a plan view showing a tape tension control device according to an embodiment of the present invention, Fig. 2 is a plan view showing the above embodiment during return operation, and Fig. 3 is a conventional tape tension control device. In the figure, l is a reel stand, 2 is a reel, 3 is a magnetic tape, 4a and 4b are tape guides, 6 is a tension arm, 11 is a tension spring, 14 is a tension band, and 16 is a tension spring. The band locking member 19 is a stopper, and 21 is a tension spring. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] a tension arm that acts to press the magnetic tape pulled out from the reel set on the reel stand against the tape guide; a tension band locking member that is movably attached to the base; The tension band is provided with a tension band having each end connected to a tension band locking member and the tension arm, and the tension band engaging member is configured to apply a tension substantially equal to the tension applied to one of the tension bands to the other tension band by the action of the tension arm. A tape tension control device characterized in that a stop member is elastically biased.