JPH0454585Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a tape loading device that is most suitable for application to, for example, a video tape recorder.

[Summary of the idea]

In this invention, a worm rotatably driven by a motor rotates a worm wheel through the compression repulsive force of a compression coil spring, and a loading arm driven by the worm wheel moves the tape guide to the unloading position. In the tape loading device configured to drive the loading arm from the worm wheel to the loading position, when the loading arm is driven by the worm wheel or the driving member driven by the worm wheel, the operating torque is configured to be stronger than the spring force of the compression coil spring. By driving the loading arm through a torque limiter mechanism, the tape, tape guide, and peripheral mechanical parts can be safely protected in the event that excessive tension is applied to the tape while it is running.

[Conventional technology]

Regarding a tape loading device for a video tape recorder, the applicant of the present invention
58-114044), and the reference example shown in Figures 3 and 4 is an improvement on that earlier application.

This reference example includes a drive shaft 1 that is rotationally driven by a motor, and a worm 2 that is movably attached to the outer circumference of the drive shaft 1 in a state where rotational force can be transmitted from the drive shaft 1. , a pair of compression coil springs 3a and 3b attached to the outer periphery of the drive shaft 1 to press and urge the worm 2 in the axial direction, a worm wheel 4 rotationally driven by the worm 2, and the worm wheel 4. This tape loading device is equipped with a loading arm 6 which is driven by a motor to drive a tape guide 5 from an unloading position to a loading position. A drive pin 8 attached perpendicularly to the drive shaft 2 is inserted into a long hole 10 along the axial direction provided in the shaft hole 9 of the worm 2, and the drive shaft is connected to the drive shaft through this drive pin 8. 1 is transmitted to the worm 2. Further, the pair of compression coil springs 3a and 3b are connected to the worm 2 on the outer periphery of the drive shaft 1.
These compression coil springs 3a, 3b are attached to the respective pairs of stopper rings 11a, 11b, 12 attached to the drive shaft 2.
A pair of washers 13a and 1 between a and 12b, respectively.
3b, 14a, and 14b.
Further, the worm wheel 4 is rotatably attached to a support shaft 15, and the loading arm 6 is fixed to the worm wheel 4 with a plurality of screws 16. Further, the tape guide 5 is moved along a guide rail 18 on a moving base 19.
A pair of guide pins 2 are attached to the lower part of the moving table 19.
0a and 20b are guide grooves 21 of the guide rail 18
It is configured to be guided by. A connecting pin 22 is attached to the tip of the loading arm 6.
The tip of the link 23 connected via the guide pin 20a is connected to one of the guide pins 20a.

According to this reference example, first, during loading, the drive shaft 1 is driven to rotate in the direction of arrow a by the forward rotation of the motor, and the worm wheel 4 is driven to rotate in the direction of arrow b by the worm 2. , the loading arm 6 is driven integrally with the worm wheel 4 in the same direction. Then, the moving table 19 is driven along the guide rail 18 via the link 23, and the tape guide 5 is moved as shown in FIG.
It is driven in the direction of arrow c from the unloading position shown by the dotted chain line to the loading position shown by the solid line. As a result, the magnetic tape 25 is pulled out from inside the tape cassette (not shown) by the tape guide 5 to the outside of the tape cassette, and the tape guides 26 and 27, which are fixed in position, for example, as shown by solid lines in FIG.
The vehicle is loaded onto a predetermined running path that spans the road.

At this time, when the tape guide 5 is moved to the loading position, as shown by the solid line in FIG. The loading arm 6 is also stopped via the link 23. However, the drive shaft 1, which is rotationally driven by the motor, continues to be over-rotated in the direction of arrow a and then stopped. and,
Due to this overrun rotation of the drive shaft 1, the worm 2 moves one of the compression coil springs 3a to the washer 1.
The compression coil spring 3a is moved in the direction of arrow d on the drive shaft 1 while being compressed between the coil springs 3a and 14a.
The movable table 19 is pressed against the stopper 28 by the compressive repulsion force. As a result, the tape guide 5 is positioned at the loading position, and loading is completed.

In addition, during unloading, the drive shaft 1 is driven in the direction of the arrow a' by the reverse rotation of the motor, and the loading arm 6 is driven in the direction of the arrow b' by the worm 2 via the worm wheel 4. , the tape guide 5 is moved from the loading position indicated by the solid line in FIG.
It is driven in the direction of arrow c' to the unloading position shown by the dotted chain line. Then, due to the overrun rotation of the drive shaft 1 after the movable table 19 contacts the stopper 29 on the other end of the guide rail 18, the worm 2 compresses the other compression coil spring 3b in the direction of arrow d'. , the movable table 19 is pressed against the stopper 29 by the compressive repulsion force.

[Problem that the invention attempts to solve]

In this reference example, when excessive tension is applied to the running magnetic tape 25 due to some abnormality while the magnetic tape 25 is running, the worm 2 on the drive shaft 1 is moved against the compression coil spring 3a. The tape guide 5 can be moved (released) in the direction of arrow d from the position shown by the solid line to the position shown by the dashed-dotted line in FIG. It is made to escape in the direction of arrow c′, which is the unloading direction, to the position.

However, the distance l ₁ that the tape guide 5 can escape in the direction of arrow c' is limited by the maximum compression amount of the compression coil spring 3a. That is, the compression coil spring 3
When a is compressed to the maximum between washers 13a and 14a, the worm 2 will no longer be compressed by the arrow d.
At the same time, the tape guide 5 is also unable to escape in the direction of arrow c', and the impact energy of the magnetic tape 25 due to the excessive tension cannot be sufficiently absorbed.

Therefore, in this reference example, when excessive tension is applied to the magnetic tape 25, the magnetic tape 25 is stretched or cut, the tape guide 5 is deformed such as inclination, and the peripheral mechanism (in this case, the worm 2 or the worm wheel 4 etc.) could easily occur.

In this reference example as well, if a sufficiently long compression coil spring 3a is used to increase the amount of movement of the worm 2 in the direction of arrow d, the distance l that the tape guide 5 can escape in the direction of arrow c' can be increased. ₁ can be made large, and the impact energy of the magnetic tape 25 due to excessive tension can be sufficiently absorbed.

However, if such a long compression coil spring 3a is used, the space factor becomes worse and the tape loading device becomes larger, so there is a limit to the length of the compression coil spring 3a.

Therefore, the present invention is designed to allow the tape guide to escape by a large distance in the unloading direction when excessive tension is applied to the tape while it is running.

[Means for solving problems]

In the tape loading device described above, the present invention provides a torque limiter mechanism between the worm wheel or a drive member rotationally driven by the worm wheel and the loading arm, and the operating torque of the torque limiter mechanism is applied to the compression coil. The spring force is stronger than that of the spring, and the loading arm is driven from the unloading position to the loading position by a worm wheel or a driving member via a torque limiter mechanism.

[Effect]

According to the present invention, when excessive tension is applied to the running tape, the worm moves against the compression coil spring and the tape guide escapes a little in the unloading direction, but the compression coil spring is compressed to the maximum. After the tension is applied, the tape guide can escape in the unloading direction against the operating torque of the torque limiter mechanism, and the distance over which the tape guide can escape in the unloading direction against excessive tension can be increased.

〔Example〕

Below, a first embodiment of the invention in which the present invention is applied to a tape loading device for a video tape recorder will be described.
This will be explained with reference to Figures A to 2B. Note that the same reference numerals are given to the same structural parts as those of the reference example shown in FIGS. 3 and 4, and the explanation thereof is omitted.

First, the loading arm 6 is rotatably supported around a support shaft 15 so that the loading arm 6 can rotate relative to the worm wheel. A torque limiter mechanism 34 is provided between the upper surface of the rotating plate 33 that rotates together with the worm wheel 4 and the lower surface of the loading arm 6. Note that a retaining ring 35 for the loading arm 6 is attached to the upper end of the support shaft 15.

This torque limiter mechanism 34 includes an engaging portion 36 made of a hole or a recess, and an engaging body 3 made of a sphere or the like.
7, and a spring 38 made of a compression coil spring or the like that presses the engaging body 37 to engage the engaging portion 36.
It is composed of: In this embodiment, for example, three recesses 39 are provided on the rotary plate 33 side at 120° intervals on the same circumference, and these recesses 3
9 respectively house an engaging body 37 and a spring 38, and on the loading arm 6 side, for example, three engaging portions 36 are provided at 120° intervals on the same circumference as the recess 39. Note that the recess 39 may be provided on the loading arm 6 side, and the engaging portion 36 may be provided on the rotating plate 33 side. And this torque limiter mechanism 3
The operating torque which is the torque by which the engaging body 37 of No. 4 drives the engaging part 36 (the same applies to the detachment torque which is the torque by which the engaging body 37 disengages from the engaging part 36) is the spring force of one compression coil spring 3a ( (compression repulsion). Note that the restoring torque, which is the torque by which the engaging body 37 of the torque limiter mechanism 34 engages with the engaging portion 36, is configured to be sufficiently smaller than the operating torque, and the spring force (compressive repulsion force) of the other compression coil spring 3b is configured to be sufficiently smaller than the operating torque. ) is set based on the restoring torque.

According to this tape loading device, first,
When unloading is complete, tape guide 5
has been moved back to the unloading position shown by the two-dot chain line in FIG. 1A, and the torque limiter mechanism 34 is in the operating state shown in FIG. 2A.
are engaged with three engaging portions 36 by springs 38, respectively.

Next, during loading, as shown in FIG. 1A, the drive shaft 1 is driven to rotate forward in the direction of arrow a by the forward rotation of the motor, and the worm wheel 4 is driven to rotate in the direction of arrow b by the worm 2. The worm wheel 4 drives the loading arm 6 in the direction of arrow b via the torque limiter mechanism 34. Then, the moving table 19 is driven along the guide rail 18 via the link 23, and the tape guide 5 is driven in the direction of arrow c from the unloading position shown by the two-dot chain line to the loading position shown by the solid line. As a result, the tape guide 5 pulls out the magnetic tape 25 from inside the tape cassette to the outside of the tape cassette, and loads it onto a predetermined running path stretched over tape guides 26, 27, etc. as shown by solid lines.

At this time, as shown by the solid line, when the tape guide 5 is moved to the loading position and the moving table 19 is brought into contact with the stopper 28 by the V groove 30 and stopped, the worm is 2 moves in the direction of arrow d on the drive shaft 1 to compress the compression coil spring 3a, and the tape guide 5 is positioned at the loading position by the compression repulsion force of the compression coil spring 3a.

Next, if excessive tension is applied to the magnetic tape 25 while it is running, first
As shown by the one-dot chain line in Figure A, the worm 2 resists the compression coil spring 3a and escapes in the direction of arrow d, and the tape guide 5 moves in the unloading direction from the loading position indicated by the solid line to the position indicated by the one-dot chain line in Figure 1A. In the direction of arrow c′, the same distance l ₁ as in the reference example mentioned above.
Just run away.

Next, as shown in FIG. 1B, after the compression coil spring 3a is compressed to the maximum, the three engaging bodies 37 of the torque limiter mechanism 34 are moved against the springs 38, respectively, as shown in FIG. 2B. The torque limiter mechanism 34 is disengaged from the engaging portion 36 and becomes inactive.

As a result, the loading arm 6 is attached to the rotating plate 33.
The tape guide 5 rotates in the direction of arrow b' from the position indicated by the one-dot chain line in FIG. (1 in Figure 1A)
From the same position as the dotted chain line position) to the solid line position in the direction of arrow c′, which is the unloading direction, distance l ₂
He is let go. Furthermore, this torque limiter mechanism 3
According to No. 4, the loading arm 6 can be released up to 120° in the direction of arrow b'.

That is, according to this tape loading device,
Compression coil spring 3 for positioning the tape guide 5
a and the torque limiter mechanism 34 are used in series, and when excessive tension is applied to the running magnetic tape 25, the compression coil spring 3a and the torque limiter mechanism 34 reduce the excessive tension by 2.
The tape guide 5 can escape from the loading position by a large distance (l ₁ +l ₂ ) in the direction of arrow c', which is the unloading direction.

In addition, as shown by the two-dot chain line in FIG. 1A, by the same unloading operation as in the reference example mentioned above,
After the moving table 19 comes into contact with the stopper 29 and is stopped, as shown in FIG. 2A, the three engaging bodies 37
are respectively reengaged with the three engaging portions 36 by the springs 38, and the torque limiter mechanism 34 is restored to its operating state again.

Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments, and various effective changes can be made based on the technical idea of the present invention.

For example, in the embodiment, the loading arm 6 is directly rotationally driven by the worm wheel 4, and a torque limiter mechanism 34 is provided between the two.
However, a drive member that is rotationally driven by the worm wheel 4 is provided, and the loading arm 6 is rotationally driven by the drive member, and a torque limiter is provided between the drive member and the loading arm. A mechanism may be provided.

Further, the torque limiter mechanism is not limited to the embodiments, and torque limiter mechanisms having various structures can be used, such as one in which the loading arm is rotationally driven by a worm or a driving member via a friction plate or the like.

Furthermore, the present invention is not limited to tape loading devices for video tape recorders, but can be applied to tape loading devices for various recording and reproducing devices, information processing devices, and the like.

[Effect of idea]

As mentioned above, when excessive tension is applied to the running tape, the present invention moves the worm against the compression coil spring to allow the tape guide to escape a little in the unloading direction. After being compressed, the tape guide can be released in the unloading direction against the operating torque of the torque limiter mechanism, and the distance that the tape guide can escape in the unloading direction against excessive tension can be increased. Therefore, the impact energy of the tape due to excessive tension can be sufficiently absorbed. Therefore, it is possible to prevent stretching or cutting of the tape, deformation such as tilting of the tape guide, and damage to peripheral mechanisms due to excessive tension applied to the tape, resulting in extremely high safety.

However, according to the present invention, there is no need to use a particularly long compression coil spring for positioning the tape guide at the tape loading position, so the space factor is good and the tape loading device becomes larger. Not at all.

[Brief explanation of the drawing]

Figures 1A to 2B show an embodiment of the tape loading device of the present invention.
Figures A and 1B are overall plan views, and Figures 2A and 2B are developed cross-sectional views of the same. FIG. 3 is an overall plan view showing a reference example, and FIG. 4 is a developed cross-sectional view of the same. In addition, in the symbols used in the drawings, 1... Drive shaft, 2... Worm, 3a... Compression coil spring, 4... Worm wheel, 5... Tape guide, 6... Loading arm, 25... Magnetic Tape, 34...torque limiter mechanism.

Claims (1)

[Claims for Utility Model Registration] A drive shaft rotationally driven by a motor, a worm attached to the outer periphery of the drive shaft so as to be movable in the axial direction in a state capable of transmitting rotational force from the drive shaft; a compression coil spring attached to the outer periphery of the drive shaft to press and bias the worm in the axial direction;
A tape loading device comprising a worm wheel rotationally driven by the worm, and a loading arm driven by the worm wheel to drive a tape guide from an unloading position to a loading position, A torque limiter mechanism is provided between the worm wheel or a drive member rotationally driven by the worm wheel and the loading arm,
The operating torque of the torque limiter mechanism is configured to be stronger than the spring force of the compression coil spring, and the loading arm is configured to be driven from the unloading position to the loading position by a worm wheel or a driving member via the torque limiter mechanism. A tape loading device featuring: