JPS6224339Y2 - - Google Patents

Description

[Detailed explanation of the invention] Among the helical VTRs for broadcasting, SMPTE type C
A format VTR is constructed as shown in Figure 1.

In the figure, 1 is a supply side reel stand, 2 is a take-up side reel stand, 3 to 5 are guide rollers, and 6 is a reel stand on the take-up side.
1 is a tape tension adjustment device on the supply side, which has a tension arm 7 and a fixing post 8 in this example attached to the tip of the tension arm 7. When the tension arm 7 is at the minimum tape tension (0gr), it is at the position 7a (slightly inside the direction connecting the tangents of the supply side reel stand 1 and the guide roller 3), and the tension arm 7 is at the maximum tape tension (about 400gr). ), it is adjusted to be at position 7b (slightly outside the direction in which the tangents of the pair of guide rollers 3 and 4 are connected).

10 is a rotating drum equipped with a rotating magnetic head device, and the magnetic tape 11 is formed into an Ω-shape by a tapered guide post 12 provided on the entry side and a pair of inclined guide posts 13 and 14 for regulating the wrapping angle. rolled around.

In addition, in this embodiment, a pair of guide posts 1
3, 14, the guide roller 5, the tapered guide post 12, and the full-width erasing head 16 are configured to be movable to the positions indicated by the chain lines, thereby facilitating the loading of the tape 11 onto the rotating drum 10. .

15 is an impedance roller, and
16 is a full-width erasing head, 17 is an erasing head for audio signals, 18 is a recording/reproducing head for audio signals, and 19 is a monitoring head. Further, 20 is a guide post, 21 is a capstan, 22 is a pinch roller, 23 is a timer roller, 25 is a tape tension adjustment device on the winding side, 26 is a tension arm, and 27 is a fixed post. It is adjusted so that it is at the position 26a when the tension is at the minimum, and at the position 26b when the tension is at the maximum.

FIG. 2 shows a conventional example of a crimping device 30 for a pinch roller 22, which has a support lever 31, which is rotatably supported around a fulcrum 32 provided at the center, and has one end attached to the pinch roller. 22, an actuator 34 of a plunger 33 is attached to the other end. If the plunger 33 is energized and the actuator 34 is pulled,
The pinch roller 22 is pressed against the capstan 21 as shown by the dashed line.

Now, in this conventional crimping device 30, as shown in the figure, the pinch roller 22 is connected to the actuator 34 of the plunger 33 via the support lever 31. 21, the third
As shown in the figure, the support lever 31 is biased in the direction of the arrow b by the force of the actuator 34 (arrow a) applied thereto.

At this time, since the support lever 31 is fixed only by the shaft 32, the upper end of the shaft 32 deviates in the direction of arrow b. As a result, the pressing force of the pinch roller 22 against the capstan 21 differs slightly between its upper and lower parts, and this variation in pressing force causes the tape 11 to vibrate or its height to fluctuate. or, in extreme cases, it may cause a wakame-like appearance.

In particular, if the height of the tape 11 is off, the relative position between the audio track and the audio head will change slightly. Therefore, to prevent this from happening, the pinch roller 22 itself is given a slight inclination in advance so that when the pinch roller 22 is pressed against the capstan 21, the pressing force is uniform. However, since the inclination of the pinch roller 22 required to obtain this uniform pressing force is on the order of several tens of microns in terms of length, adjusting the inclination requires considerable time and skill.

Therefore, in this invention, such a tape 11
Pinch roller 2
This paper proposes a pinch roller crimping device that eliminates the need for tilt adjustment as described in step 2.

FIG. 4 shows an example of the crimping device according to this invention. It is composed of a lever 45 and a connecting arm 50 that connects the support arm 40.

The support arm 40 is an arm with a U-shaped cross section that is rotatably attached to the substrate around a fulcrum 41. The pinch roller 22 is attached to a shaft 42 provided at a part of the tip, and the pinch roller 22 is attached to a shaft 42 provided at a part of the tip. A mounting piece 43 for rotatably mounting one end of the connecting arm 50 is integrally formed on the other part. 43a
is its fulcrum.

The movable lever 45 is bent into a substantially dogleg shape,
A rotation fulcrum 46 is provided at the bending center, and an attachment lever 47 is further rotatably attached to this rotation fulcrum 46. The tip of the actuator 34 is attached to the tip of the attachment lever 47. 47a is its pivot support. A pressing force adjustment mechanism 55 for the pinch roller 22 is provided between the attachment lever 47 and the tip of the one half portion 45A of the movable lever 45. As shown in the figure, this mechanism 55 includes an adjustment shaft 56 and a pressure adjustment spring 57 that are stretched between the two.
The adjustment shaft 56 is fixed to the one half 45A side, and therefore the adjustment shaft 56 is connected to the mounting lever 47 from the actuator 34.
The force transmitted thereto is transmitted to the movable lever 45 via this pressing force adjustment mechanism 55.

Note that the other half 45B of the movable lever 45
The other end of the connecting lever 50 is rotatably attached to the tip of the connecting lever 50 . 48 is its fulcrum.

Now, in the crimping device 30 in this example,
FIG. 5 shows a state in which the actuator 34 is pulled by the plunger 33 and the pinch roller 22 is pressed against the capstan 21. As shown, fulcrum 4
8, 43a, 42, the center points of the capstan 21 are aligned substantially in a straight line along the line of action la, and the pinch roller 22 is pressed against the capstan 21 by applying a force in the direction of the line of action la. . Therefore, since the force applied to the pinch roller 22 is uniform in the axial direction, the pinch roller 22 is evenly pressed against the capstan 21. For this reason,
The shaft 41 is an arm 40 that supports the pinch roller 22.
It is sufficient if the shaft 41 is simply rotatably supported, and even if the shaft 41 is slightly bent, the uniformity of the pressing force of the pinch roller 22 against the capstan 21 is not affected. Furthermore, in the crimping device 30 in this example, one fulcrum 43a of the connecting lever 50 is designed to be slightly closer to the fulcrum 41 than the line of action la connecting the fulcrums 42 and 48. , in the separated state shown in FIG. 4, the fulcrums 43a and 4
The separation distance of the pinch rollers 22 is selected so that the line of action lb connecting the pinch rollers 8 is located closer to the fulcrum 42 than the fulcrum 41.

In this case, if the plunger 33 is urged and the actuator 34 is pulled from the state shown in FIG. 4, the movable lever 45 will rotate clockwise.
The support arm 40 is rotated counterclockwise via the connection lever 50, and the pinch roller 22 is pressed against the capstan 21.

Further, since the force of the plunger 33 is applied to the fulcrum 46 of the movable lever 45, a force is applied to the fulcrum 46 to bias its upper end, causing the upper end to deviate slightly in the direction of arrow C in FIG. However, even if the axis serving as the fulcrum 46 is slightly deviated in the direction of arrow C,
As a result, the upper end of the pinch roller 22 will not be biased in the direction of arrow C. That is, the fulcrums 43 provided at both ends of the connecting lever 50
Since each of the mounting shafts a and 48 has some play, the amount of deviation of the fulcrum 46 is absorbed by this play and does not affect the pinch roller 22 at all.

Therefore, the capstan 2 of the pinch roller 22
1 becomes uniform in the width direction of the tape 11, and as a result, deviations in the height of the tape 11, etc. are eliminated.

Also, the fulcrum 43a is slightly wider than the line of action la.
Since the movable lever 45 is designed to be biased toward the fulcrum 41 side, a portion of the force applied to the movable lever 45 is also applied to the fulcrum 41 side of the support arm 40, and this force causes the shaft that becomes the fulcrum 41 to move between the support arm 40 and the support arm 40. Even if there is a backlash, this backlash can be absorbed. As a result, the pressing force of the pinch roller 22 against the capstan 21 becomes more uniform.

By the way, in this embodiment, the pinch roller 22
The fulcrum 41 of the support arm 40 supporting the capstan 21 is selected to be on the side opposite to the movable lever 45 side with respect to the capstan 21, and this is based on the following reasons.

Now, if the rotation angle of the support arm 40 from the position shown in FIG. ₄ to the position shown in FIG.
4 when placed on the line connecting this fulcrum 41 and the point of action q and on the opposite side of this fulcrum 41.
1', the rotation angle of the other half 45B of the movable lever 45 is the same as that of the fulcrum ₄ in order to obtain the same rotation angle θ1 since the length of the connecting lever 50 is fixed.
In the case of 1, only a rotation angle of θ ₃ is sufficient, whereas in the case of the fulcrum 41', the rotation must be made up to θ ₂ (θ ₂ >θ ₃ ).

In this way, the required rotation angle of the movable lever 45 is different depending on whether the fulcrum 41 is selected on the movable lever 45 side from the point of action q or on the opposite side. The rotation angle can be reduced by selecting . Therefore, if the fulcrum is determined as in the embodiment, the actuator 34 of the plunger 33
The suction stroke is smaller than when the fulcrum is set at 41', a smaller plunger can be used, and power consumption can be reduced.

As explained above, according to this invention, the fulcrum 4
8, 43a, 42 and the center points of the capstan 21 are configured to be substantially in a straight line. Then, the center point of the pinch roller 22 and the capstan 2
Pinch roller 2 along the straight line connecting the center point of 1
2 is pressed against the capstan 21. Therefore, since the force applied to the pinch roller 22 is uniform in the axial direction, the pinch roller 22
is evenly pressed against the capstan 21.
Therefore, the shaft 41 only needs to be able to rotatably support the arm 40 that supports the pinch roller 22.
Even if the shaft 41 is slightly bent, the pressing force of the pinch roller 22 against the capstan 21 is uniform;
The tape 11 no longer vibrates or fluctuates in height. Therefore, there is no need to install the pinch roller 22 itself with a slight inclination or to adjust the inclination.

Although this invention has been applied to a pinch roller crimping device used in a SMPTE type C format VTR, it can also be applied to other VTRs.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a VTR used to explain this invention, Fig. 2 is a plan view showing a conventional example of a crimping device, Fig. 3 is a side view thereof, and Figs. 4 and 5 are crimping devices according to this invention. FIG. 6 is a block diagram showing an example of the device, and is a diagram for explaining this invention. 21 is a capstan, 22 is a pinch roller, 3
0 is a crimping device, 33 is a plunger, 40 is a support arm, 45 is a movable lever, 50 is a connecting arm,
41, 43a, 48, and 46 are fulcrums.

Claims (1)

[Scope of utility model registration request] In a device for crimping a pinch roller to a capstan, a movable lever is rotatably attached to an actuator of a plunger by a first rotation shaft, and a second
a connecting arm, one end of which is rotatably attached to the movable lever by a shaft; one end of the connecting arm is rotatably attached to the other end of the connecting arm by a third shaft; A support arm for a pinch roller is rotatably mounted on a substrate by a shaft, and when the plunger is operated to press the pinch roller to the capstan, the second,
A pinch roller crimping device configured such that a third shaft, a rotation center of the pinch roller, and a rotation center of the capstan are substantially in a straight line.