JPH0333963Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a rotation control device for a reel stand of a video tape recorder.

(Prior Art) Generally, when loading and unloading a VTR, the tape is pulled out or wound only from one reel, for example, a take-up reel.

In this case, an auxiliary brake is required to apply a brake to the other reel, such as the supply reel, during loading and unloading, and to release the brake when the operation is completed.

As an example of this auxiliary brake, mechanisms shown in FIGS. 8 and 9 have been proposed. FIG. 8 shows the state of the auxiliary brake during unloading, and FIG. 9 shows the state of the auxiliary brake at the end of unloading.

The supply reel stand 31 has a toothed portion 21 on its outer periphery with which the tip of the brake lever 2 can engage.

A gear 22 that rotates while meshing with the tooth surface 10 of the loading ring 1 is disposed on the pivot portion of the brake lever 2 via a felt (not shown), and the brake lever 2 is rotated by friction in the direction of rotation of the gear 22. Rotate by following.

A swinging lever 24 swinging around a support shaft 23 is provided between the loading ring 1 and the supply reel stand 31, and one free end of the lever 24 is provided with a concave cam surface 11a on the outer periphery of the loading ring 1. A roller 25 is provided which fits into the roller 25 with a spring 26.
is biased toward the loading ring 1 side.

The free end of the swing lever 24 on the roller 25 side and the free end of the brake lever 2 are connected via a connecting piece 27. The above auxiliary brake mechanism is
As shown in Figure 8, during unloading,
The loading ring 1 rotates clockwise, the gear 22 rotates counterclockwise, and the brake lever 2, which is frictionally engaged with the gear 22 by felt, also rotates counterclockwise.

The roller 25 has come off the concave cam surface 11a of the loading ring 1, and the swing lever 24 is in a position rotated counterclockwise from its home position. 21 to prevent the supply reel stand 31 from rotating.

Therefore, the tape is wound only toward the take-up reel stand 3 side.

Next, when unloading is completed, as shown in FIG. 9, the loading ring 1 stops, the roller 25 engages with the concave cam surface 11a of the ring 1, and the swing lever 24 is moved clockwise by the spring 26. Rotate to .

At this time, the brake lever 2 connected to the lever 24 via the connecting piece 27 is also pulled toward the loading ring 1, and the engagement between the brake lever 2 and the supply reel stand 31 is released.

In addition to the above-mentioned brake devices, the rotation control device for the reel stands 3, 31 includes a main brake device (not shown) that brakes both reel stands 3, 31 when stopped, and a supply reel stand 31 that controls the rotation of the reel stands 3, 31 according to the tension of the tape pulled out. A tension brake device (not shown) is required to keep the tape tension at an optimal level by applying the brake gently.

(Problems to be solved by the invention) The auxiliary brake device shown in FIGS. 8 and 9 is already complicated in itself, but it also includes three brake devices: a tension brake device and a main brake device. The conventional rotation control device for a reel stand has many components, which increases the number of assembly steps and increases costs.

(Means for solving the problem) A pair of brake levers 4 and 5 are swingably provided between the loading ring 1 and the supply reel stand 31 and take-up reel stand 3.

Both brake levers 4 and 5 have brake shoes 4 at their outer free ends that can come into contact with the mating reel stands 31 and 3.
1 and 51, each having an engaging portion 4 at its inner free end.
0 and 50 are provided and the engaging portions 40 and 50 are butted against each other, and both brake levers 4 and 5 are connected to the brake shoe 4.
1 and 51 are urged by a spring 6 in the direction of pressing the reel stands 31 and 3.

An engaging portion 50 of one lever, the brake lever 5 on the winding side in the embodiment, forms a projecting piece 52 toward the mating engaging portion 40 .

The engaging portion 40 of the other lever 4, the brake lever 4 on the supply side in the embodiment, has a first recess 42 into which the protruding piece 52 is fitted, and a second recess shallower than the first recess 42.
When the recess 43 is formed and the protruding piece 52 corresponds to the first recess 42, the protruding piece 52 is allowed to enter the first recess 42, and both brake levers 4 and 5 are rotated in opposite directions by the spring 6. then brake show 4
1,51 hits the opponent's reel stand 31,3.

When the protruding piece 52 hits the second recess 43, the brake levers 4, 5 push against each other with the brake shoes 41, 51 spaced apart from the mating reel stands 31, 3.

Further, both the engaging parts 40, 50 have abutting parts 44, 54 on which presser pieces 71, 72 of the switching lever 7, which will be described later, come into contact.
extends toward the mating engagement part.

Loading ring 1 and brake levers 4 and 5
A switching lever 7 is swingably disposed between the switching lever 7 and the loading ring 1 side, and one end of the switching lever 7 on the loading ring 1 side is an operating piece 73 that can engage with a cam surface 11 formed on the loading ring 1. , the other end is bifurcated and is opposed to the contact portions 44, 54 of the brake levers 4, 5, respectively.

Further, the switching lever 7 is urged by a spring 8 to a neutral position with respect to both brake levers 4 and 5.

The cam surface 11 of the loading ring 1 is a first concave cam surface 1 into which the actuating piece 73 of the switching lever 7 is fitted when stopped as shown in FIG. 1 and when loading is completed as shown in FIG.
1a and a second concave cam surface 11b.

A tension adjustment brake device 9 is provided between the loading ring 1 and the supply reel stand 31 to automatically adjust the tape tension.
This is disclosed in detail in Japanese Patent Application Laid-Open No. 171760/1983, and is known in the art. Rotation of the loading ring 1 operates the tape tension lever 91 to pull out the tape from the cassette. If the tension of the tape acting is small, the brake piece 92 connected to the tension lever 91 is lightly pressed against the supply reel stand 31, and if the tension of the tape acting on the tension lever 92 is large, the brake piece 92 is pressed against the supply reel stand 31.
The tension of the tape is kept constant by adjusting the load when pulling out the tape.

(Operation) Stopped state As shown in Fig. 1, the protruding piece 52 of the brake lever 5 on the winding side is fitted into the first recess 42 of the mating brake lever 4, and the brake shoes 41, 51 of both brake levers 4, 5 are connected to the mating brake lever 5. Press the reel stands 31, 3,
Rotation of both reel stands 3 and 31 is prevented.

At the start of loading, as shown in FIG. 2, the loading ring 1 rotates counterclockwise, the operating piece 73 of the switching lever 7 overcomes the first concave cam surface 11a of the loading ring 1, and the switching lever 7 rotates clockwise. Rotate to . At this time, the presser piece 71 corresponding to the abutment part 44 of the brake lever 5 on the supply reel stand 31 side presses the abutment part 44 to slightly rotate the brake lever 4 on the supply reel stand 31 side clockwise.

By clockwise rotation of the brake lever 4 on the side of the supply reel stand 31, the first recess 4 of the lever 4 is rotated.
2 and the second recess 43 form the take-up reel stand 3.
The protruding piece 52 of the brake lever 5 on the side is pressed to rotate the brake lever 5 counterclockwise.
3.

In the above state, both brake shoes 41, 51 are separated from the reel stands 3, 31.

Moreover, since the supply side reel stand 31 is lightly braked by the tension brake piece 92, when the tape is pulled out by the tape pull-out pin 12 on the loading ring 1, the brake is not applied. The tape is pulled out from the side of the take-up reel stand 3 that is not in use.

Upon completion of loading When the loading ring 1 rotates to the loading completion position as shown in FIG. to return to.

However, both the brake levers 4 and 5 are pushed against each other by the spring 6 while the protruding piece 52 and the second recess 43 are engaged, and the brake shoes 41 and 51 are separated from the mating reel stands 3 and 31. The brake is kept in a released state, and there is no problem with tape forwarding during playback, etc.

At the start of unloading, the loading ring 1 rotates clockwise as shown in FIG. Brake lever 5 on the reel stand 3 side
The presser piece 72 corresponding to the abutting portion 54 presses the abutting portion 54 and rotates the brake lever 5 counterclockwise. At this time, the protruding piece 52 of the brake lever 5 comes off the second recess 43 of the mating engagement part 40 and corresponds to the first recess 42 .

As a result, the tension between the engaging parts 40 and 50 is released, and the brake lever 4 on the supply reel 31 side is rotated counterclockwise by the spring 6 to apply a brake to the supply reel 31.

The brake lever 5 on the take-up reel stand 3 side still maintains the state in which the brake of the take-up reel stand 3 is released by the switching lever 7, and the tape is wound only on the take-up reel stand 3 during unloading.

Upon completion of unloading When the loading ring 1 returns to the unloading completion position, the operating piece 73 of the switching lever 7 fits into the first concave cam surface 11a of the loading ring 1 and returns to the neutral position, as shown in FIG. Then, the system enters the stop state.

(Other Embodiments) FIG. 7 shows another embodiment in which the tape is pulled out from the supply reel side during loading and unloading, and the tape is rewound. protrusion 5
2 is provided protrudingly, and first and second recesses 42 and 43 similar to those described above are formed in the brake lever 5 on the take-up reel stand 3 side.

When the switching lever 7 rotates counterclockwise during unloading, the brake lever 4 on the supply reel stand 31 side rotates clockwise, causing the supply reel stand 3
Since the movements are the same as those described above except for releasing the brake No. 1, detailed explanation will be omitted.

[Brief explanation of drawings]

Figure 1 is a plan view in the stopped state, Figure 2 is a plan view during loading, Figure 3 is a plan view when loading is complete, Figure 4 is a plan view during unloading, and Figure 5 is the supply reel stand side. 6 is a plan view of the brake lever on the take-up reel stand side, FIG. 7 is a plan view of another embodiment,
FIGS. 8 and 9 are explanatory diagrams of a conventional auxiliary brake device. 1... Loading ring, 4, 5... Brake lever, 3, 31... Reel stand, 7... Switching lever.

Claims (1)

[Scope of utility model registration request] At the start of loading of the loading ring 1, the tension lever 91 operates in the direction of pulling out the tape, and a gentle brake is applied to the supply reel stand of the take-up reel stand and the supply reel stand, depending on the tension acting on the tension lever. In the reel stand rotation control device equipped with a tension adjustment brake 92, there are brake shoes 41, 51 at one end,
A pair of brake levers 4, 5 each having an engaging part 40, 50 at the other end are brought into contact with each other's engaging parts 40, 50, and the brake shoes 41, 51 are opposed to the mating reel stands 3, 31, respectively. Reel stand 3, 31
Both brake levers 4,
5 brake shoes 41, 51 on the other reel stand 3,
31 is biased by a spring, and the engaging portion 50 of one lever 5
A projecting piece 52 is formed toward the mating engagement part 40,
The first lever 52 enters the engaging portion 40 of the other lever 4 and allows the levers 4 and 5 to rotate in a direction that applies a brake to the reel stands 3 and 31.
Continuing from the recess 42 and the recess 42, the protruding piece 52
Apply the brake levers 4 and 5 to 41.51
between the loading ring 1 and the brake levers 4, 5 on the engaging portions 40, 50 side of the levers 4, 5. A switching lever 7 having two presser pieces 71 and 72 that can come into contact with the free end is provided, and a spring 8 urges both brake levers 4 and 5 to a neutral position. A rotation control device for a reel stand in which a cam surface 11 for operating a switching lever 7 is formed.