JPH05290452A - Tape tension adjusting mechanism - Google Patents

Abstract

PURPOSE:To diminish a change in tape tension in the tape tension adjusting mechanism so as to stabilize a tape pass and also to expand allowable range of precision errors and assembly of errors of individual constitutive parts. CONSTITUTION:A pin 8 erected on one end side of a brake arm 7 is brought into contact with a tension regulating arm 3, on which a tape guide 2 for stretching a magnetic tape T is erected on the tip, and also a reel rotation suppressing member 9 is provided on the other end side of this brake arm 7. A fulcrum shaft 10 of this brake arm 7 is fitted on a position adjusting plate 11, and by moving a position of this position adjusting plate 11 toward the side of a chassis, a contact position between the brake arm 7 and the tension regulating arm 3 is variably adjusted, so that the tension regulating arm 3 is adjusted to a prescribed position under the traveling state of the magnetic tape T.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape tension adjusting mechanism in a recording / reproducing apparatus such as a video tape recorder (VTR).

[0002]

2. Description of the Related Art Generally, a video tape recorder (VT)
In the recording / reproducing apparatus of R), it is necessary that the magnetic tape be run in a state where an appropriate tension is applied, and the tension is required to be kept as constant as possible. ..

Particularly in a VTR or the like, it is an important condition to keep the winding of the magnetic tape around the outer peripheral surface of the head drum as stable as possible at the time of recording / reproducing information, and when the tape tension is not appropriate or changes greatly. In such a case, the winding state of the magnetic tape around the head drum becomes unstable, and accurate recording / reproduction of information cannot be performed.

For this reason, a conventional tape player in which a magnetic tape such as a VTR is wound obliquely around a rotary head drum and runs, is provided with a tape tension adjusting mechanism for keeping the tape tension substantially constant.

For example, in the conventional tape tension adjusting mechanism 31, as shown in FIG. 6, a ten-legged pin 32 for suspending a magnetic tape T is erected on a ten-legged arm 33, and the ten-legged arm 33 is horizontally oriented around a fulcrum shaft 34. Rotatably attached to the fulcrum shaft 34 in the vicinity of the engagement step 35
Is formed. Further, while the spring 36 applies a biasing force in the direction in which the above-mentioned balance pin 32 comes into contact with the magnetic tape T, a pin 38 is provided upright at one end of the brake arm 37 and a rotation suppressing member 39 is attached at the other end thereof. The brake arm 37 is pivotally attached to the vicinity of the reel base 41 by a fulcrum shaft 40, and the pin 38 of the brake arm 37 is engaged with the engagement step 35 of the balance arm 33.

With this structure, when the tape tension is weakened, the ten-leg arm 33 rotates counterclockwise about the fulcrum shaft 34 in FIG. 6, and in conjunction with this, the brake arm 37 rotates clockwise about the fulcrum shaft 40. Then, the rotation suppressing member 39 is pressed against the peripheral surface of the reel base 41.

When the tape tension becomes strong, the tension arm 33 rotates clockwise around the fulcrum shaft 34 in FIG. 6, and the brake arm 37 interlocks with this.
Rotates counterclockwise about the fulcrum shaft 40 to loosen the pressure contact of the rotation suppressing member 39 with respect to the reel base 41,
It is designed to adjust the tape tension.

Further, a vertical fixed guide 42 for changing the traveling direction of the magnetic tape T is provided in the recording / reproducing apparatus in the vicinity of the tape tension adjusting mechanism 31, and the magnetic tape is substantially symmetrical with the head drum H interposed therebetween. Fixed tilt guides 43, 43 'for tilting T, roller guides 44, 44', roller guide 45 for winding the magnetic tape T obliquely around the head drum H and guiding it again to return the magnetic tape T to the vertical state. , 45 'and tilt guides 46, 46' are provided and arranged on a moving base (not shown).

The magnetic tape T is sent from the fixed inclined guide 43 'through the capstan 47 and the moving guide 48 into the cassette C on the outlet side with respect to the head drum H so as to be wound on the other reel 49. Is becoming

In the thus configured recording / reproducing apparatus, the tension adjusting mechanism 31 configured to apply the rotational load to the reel base 41 by the brake arm 37 is a means for adjusting the positional relationship between the tenleg arm 33 and the brake arm 37. Has not been made in particular.

[0011]

As described above, in the conventional recording / reproducing apparatus, the tape tension adjusting mechanism is provided with means for adjusting the positional relationship between the tenregi arm and the brake arm. It was difficult to construct an accurate tape path because it depends on the precision of the components that make up the tension adjusting mechanism.

Further, in the conventional structure, the lever ratio which greatly affects the performance of the tape tension adjusting mechanism,
That is, the distance a from the tape guide 32 to the fulcrum shaft 34 of the balance arm 33 in FIG.
Ratio b from the fulcrum shaft 34 to the pin 38 at the tip of the brake arm 37, and the distance c from the pin 38 at the tip of the brake arm 37 to the fulcrum shaft 40 of the brake arm 37.
It was impossible to increase the ratio of the distance d from the fulcrum shaft 40 of the brake arm 37 to the contact point X between the rotation restraining member 39 of the brake arm 37 and the reel stand 41 for the sake of parts accuracy.

The present invention has been made to solve such a problem, and a tape tension adjusting mechanism capable of accurately adjusting the position of the balance arm by moving the position adjusting plate supporting the fulcrum shaft of the brake arm. The purpose is to provide.

[0014]

SUMMARY OF THE INVENTION The tape tension adjusting mechanism of the present invention solves the above-mentioned problems and achieves the above-mentioned object. For example, as shown in FIG. 1, a tension arm supporting a tape guide, A tape tension adjusting mechanism comprising a brake arm having one end in contact with the balance arm and a rotation restraining member for braking the reel base at the other end, and by moving the fulcrum shaft of the brake arm, The contact position between the brake arm and the balance arm is moved so that the balance arm can be adjusted to a predetermined position while the tape is running.

Further, a ten-leg arm having a tape guide provided upright is provided at the tip, one end side of the brake arm is connected to the ten-leg arm, and a reel rotation suppressing member is provided on the other end side of the brake arm. By mounting the fulcrum shaft on the position adjusting plate and moving and adjusting the position of the position adjusting plate, the contact position between the above-mentioned brake arm and the above-mentioned ten-leg arm is moved, and the above-mentioned ten-leg arm is moved in the running state of the magnetic tape T. It may be configured to be adjustable to a predetermined position.

[0016]

The tape tension adjusting mechanism of the present invention, which is constructed as described above, operates as follows. The position adjusting plate is moved while the magnetic tape is running, and the position of the fulcrum shaft of the brake arm is adjusted so that the engaging position of the brake arm with the balance arm is the optimum position, and then the position adjusting plate is fixed.

By adjusting the tape tension adjusting mechanism in this way, when the tape tension becomes strong, the tension arm and the brake arm react to loosen the restraining force of the rotation restraining member on the reel, and when the tape tension becomes weak, the tension arm is weakened. And, the brake arm reacts in the opposite direction to the above-mentioned case and the rotation restraining member restrains the rotation of the reel, thereby keeping the tape tension constant.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a tape tension adjusting mechanism to which the present invention is applied will be described below with reference to FIGS.

Tape tension adjusting mechanism 1 of this embodiment
Is a ten-legged arm 3 with a tape guide 2 standing upright on the tip.
Is provided, one end side of the brake arm 7 is engaged with the balance arm 3, and the rotation suppressing member 9 is provided at the other end side of the brake arm 7.

That is, the tape guide 2 is for hanging the magnetic tape T, has a cylindrical shape, and is rotatably erected on the tip of the balance arm 3.

The balance arm 3 is rotatably mounted in the recording / reproducing apparatus about a fulcrum shaft 4, and a locking step 5 is formed in the vicinity of the fulcrum shaft 4. An intermediate portion of the balance arm 3 is formed. One end of the tension spring 6 is locked to
The tape guide 2 described above is biased so as to contact the magnetic tape T.

The brake arm 7 is formed in a substantially V shape in a plan view, and a pin 8 is erected on one end side of the brake arm 7. The pin 8 is engaged with the locking step portion 5 of the balance leg arm 3 described above. A rotation restraint member 9 is provided on the other end side of the brake arm 7, and a fulcrum shaft 10 of the brake arm 7 is provided slightly from the bent portion of the substantially V-shaped brake arm 7. ..

A fulcrum shaft 10 of the brake arm 7 is pivotally attached to a position adjusting plate 11, and the position adjusting plate 11 itself is centered on a fulcrum shaft 12 provided at the end of the chassis in FIG.
Mount it so that it can rotate in the direction of arrow A or arrow B.
Further, an arc-shaped elongated hole 13 centered on the fulcrum shaft 12 is formed in a peripheral portion of the position adjusting plate 11 opposite to the fulcrum shaft 12,
The position adjusting plate 11 is fixed to the chassis by inserting a screw 14 into the elongated hole 13 and tightening it on the chassis side. The position adjusting plate 11 is fixed within a range in which both ends of the elongated hole 13 abut on the screw 14. It is rotatable about the fulcrum shaft 12 with respect to the chassis.

The rotation suppressing member 9 is provided in substantially the same direction as the tangent line on the outer circumference of the reel base 16 engaged with the reel 15, and a felt or the like is attached to the surface in contact with the outer peripheral surface of the reel base 16. It is configured.

Further, in the recording / reproducing apparatus, as in the conventional example shown in FIG.
A vertical fixed guide 17 for changing the running direction of the magnetic tape T is provided in the vicinity of the magnetic tape T, and the magnetic tape T is tilted substantially symmetrically with the head drum H sandwiched between the fixed tilt guides 18 and 18 '. Roller guides 19 and 19 ', roller guides 20 and 20', and tilt guides 21 and 21 'for guiding the winding and returning to the vertical state are provided and arranged on a moving base (not shown).

The magnetic tape T is sent from the fixed tilt guide 18 'through the capstan 22 and the moving guide 23 into the cassette C on the outlet side with respect to the head drum H so as to be wound up on the other reel 24. Is becoming

Next, the operation of the tape tension adjusting mechanism 1 of this embodiment having the above construction will be described.

First, when assembling the tape tension adjusting mechanism 1 of this embodiment, the screw 14 is loosened so that the position adjusting plate 11 can be rotated and moved about the fulcrum shaft 12, for example, in FIG. , When the rotary arm is rotated in the direction of arrow A from the position indicated by the solid line to the position indicated by the alternate long and two short dashes line, the brake arm 7 is also moved to the position indicated by the alternate long and two short dashes line by changing the position of the fulcrum shaft 10 with this movement. The position of the pin 8 on the one end side corresponding to the balance leg arm 3 changes, that is, the pin 8 moves away from the engagement step portion 5 of the balance leg arm 3, whereby the balance leg arm 3 moves the fulcrum shaft 4 in the direction of arrow D by the biasing force of the tension spring 6. It will be rotated around the center.

When the position adjusting plate 11 is rotationally moved in the direction of arrow B to the position shown by the alternate long and short dash line, the brake arm 7 is moved to the position indicated by the alternate long and short dash line, and the pin 8 is brought into engagement with the engaging step portion of the balance arm 3. 5, the tension arm 3 is rotated in the direction of arrow E against the biasing force of the tension spring 6.

In this way, by moving the position adjusting plate 11 to change the position of the fulcrum shaft 10 of the brake arm 7, the movable direction of the tension leg arm 3, that is, the tension spring 6 can be rotated by the biasing force of the tension spring 6. As the range changes, the rotation restraining member 9 of the brake arm 7 that interlocks with the rotation of the balance arm 3 changes the pressure contact state with respect to the reel base 16, and the tape tension of the magnetic tape T suspended on the balance arm 3 also changes.

This adjusting operation can be performed even when the magnetic tape T is suspended on the tension arm 3 and is in the running state, and the optimum tape tension in the running state can be given to the magnetic tape T.

After this adjustment, the screw 14 is tightened and the position adjusting plate 11 is temporarily fixed, and the locking agent is filled in the long hole 13 to fix the position adjusting plate 11 so that the tension arm 3 is positioned at an optimum position for tape tension adjustment. Can be made

When the tape cassette C is loaded into the recording / reproducing apparatus, the roller guides 19, 19 ', 2 on the moving base (not shown) are placed in the mouse portion of the tape cassette C.
0, 20 'and inclined guides 21, 21' are arranged, and the magnetic tape T in the tape cassette C is pulled out to the outside of the mouse portion by the movement of the moving base and wound around the head drum H.

After the loading, when the tape tension is weakened while the magnetic tape T is running, the tension arm 3 rotates counterclockwise in FIG. 3 about the fulcrum shaft 4 due to the biasing force of the tension spring 6. When the stop portion 5 pushes the pin 8 of the brake arm 7, the brake arm 7 rotates clockwise around the fulcrum shaft 10 in the figure, and the rotation suppressing member 9 is pressed against the reel base 16 so that the reel base 16 moves. Suppress rotation.

When the tape tension increases, the tension arm 3 rotates clockwise in FIG. 4 about the fulcrum shaft 4 as opposed to the case described above, and the brake arm 7 interlocks with the fulcrum shaft 10 as the center. As a result, the rotation of the rotation restraining member 9 against the reel base 16 is alleviated in the same figure, the reel base 16 is in a state of being rotated substantially freely, and a predetermined tape tension is applied to the magnetic tape T. A stable and stable tape path can be obtained.

As described above, the brake arm 7 is used in this embodiment.
Since the position of the fulcrum shaft 10 is adjusted by the position adjusting plate 11 and the positional relationship between the pin 8 of the brake arm 7 and the balance leg arm 3 contacting the pin 8 can be accurately set, the variation in the component dimensions is allowed within the adjustable range. Can be, Figure 5
As shown in, the distance a from the tape guide 2 to the fulcrum shaft 4 of the balance arm 3 and the fulcrum shaft 4 of the balance arm 3 are shown.
To the distance b from the end of the brake arm 7 to the pin 8 and the distance c from the pin 8 at the end of the brake arm 7 to the fulcrum shaft 10 of the brake arm 7 and the brake arm 7
The ratio of the distance d from the fulcrum shaft 10 to the contact point X between the rotation suppressing member 9 and the reel stand 16 can be set to a large value, and the tension adjusting mechanism in which the tape tension changes little from the beginning to the end in the running state of the magnetic tape T. And a stable tape path can be obtained.

The present invention can be variously modified without departing from the spirit of the invention. For example, the shapes of the ten-legged arm 3, the brake arm 7, and the position adjusting plate 11 are not limited to those of the present embodiment, and the positional relationship is not impaired. This is possible, and a brake band may be provided instead of the rotation suppressing member 9. Further, the position adjusting plate 11 or the fulcrum shaft 10 of the brake arm 7 may be provided so as to be horizontally movable instead of rotating around the fulcrum shaft 12.

[0038]

As described above, according to the tape tension adjusting mechanism of the present invention, the position of the balance arm can be adjusted to an accurate position by adjusting the position of the brake arm, so that a stable tape path can be obtained. it can. Further, the accuracy error and the assembly error of each component can be allowed within a range adjustable by adjusting the positional relationship. Further, since the above-mentioned lever ratio can be increased, it is possible to achieve tape tension adjustment with little change in tape tension applied to the magnetic tape from the beginning to the end.

[Brief description of drawings]

FIG. 1 is a schematic plan view of a recording / reproducing apparatus to which a tape tension adjusting mechanism of the present invention is applied, with a part thereof omitted.

FIG. 2 is a plan view of an embodiment of a tape tension adjusting mechanism of the present invention.

FIG. 3 is an explanatory view of the operation when the tape tension is weakened.

FIG. 4 is an operation explanatory diagram when the tape tension becomes strong.

FIG. 5 is an explanatory diagram of a lever ratio of the same.

FIG. 6 is a schematic plan view of a recording / reproducing apparatus to which a conventional tape tension adjusting mechanism is applied.

FIG. 7 is an explanatory diagram of a lever ratio of the same.

[Explanation of symbols]

 1 Tape tension adjusting mechanism 2 Tape guide 3 Tenregi arm 7 Brake arm 8 Pin 9 Rotation suppressing member 10 Support shaft 11 Position adjusting plate 12 Support shaft 13 Long hole 14 Screw 15, 24 Reel

Claims (2)

[Claims] 1. A tape tension adjusting mechanism comprising: a tension arm supporting a tape guide; and a brake arm having one end in contact with the tension arm and a rotation restraining member for braking the reel base at the other end. By moving the fulcrum shaft of the brake arm,
A tape tension adjusting mechanism capable of moving the contact position between the brake arm and the tension arm to adjust the tension arm to a predetermined position while the tape is running. 2. A ten-legged arm having a tape guide provided upright at the tip thereof is provided, one end side of the brake arm is connected to the tenre arm and a reel rotation suppressing member is provided at the other end side of the brake arm, and a fulcrum of the brake arm is provided. By mounting the shaft on the position adjusting plate and rotating the position adjusting plate, the contact position between the brake arm and the tension arm can be moved, and the tension arm can be adjusted to a predetermined position while the magnetic tape is running. The tape tension adjusting mechanism according to claim 1, wherein: