JPS629541Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a brake device that is most suitable for application to recording and reproducing devices such as VTRs, tape recorders, record players, and the like.

As is well known, for example, a soft brake used in a VTR supply reel stand is equipped with a brake shoe at the end of a brake arm that is rotatably mounted around a fulcrum shaft, and this brake arm is connected by a spring to the supply reel stand. The other end of this brake arm and the pinch roller crimping lever are connected by a wire. During tape loading, the brake shoe is lightly pressed against the circumference of the supply reel stand by the spring force, and the brake is applied to the supply reel stand, thereby preventing the tape from being unnecessarily fed out during tape loading. prevent. On the other hand, when the FWD button is pressed after tape loading is completed, the pinch roller crimping lever is rotated by the suction rod of the plunger solenoid, and the tape is crimped to the capstan by the pinch roller, and the tape is crimped to the capstan via the wire. The brake arm is rotated against the spring to move the brake shoe away from the supply reel stand and release the brake on the supply reel stand.

Recently, with the miniaturization of VTRs, very small plunger solenoids have been used, and the suction force of the suction rod when energized has become very weak. On the other hand, the action of pressing the pinch roller against the capstan by the suction action of the suction rod is performed against the pinch roller pressing spring associated with the pinch roller pressing lever, and the load that the suction rod receives at this time is comparatively It's a big target. Therefore, conventionally, when the suction stroke of the suction rod is, for example, 4 mm, the pinch roller is crimped with a stroke of 4 mm, and the brake of the supply reel stand is released, for example, at the last 1 mm when the suction force of the suction rod is strong. In this way, the timing between the start of the pinch roller's crimping operation and the start of the brake release operation is shifted, and the load is adjusted to match the change in the suction force of the suction rod, so that a large load is not applied to the suction rod at once. This prevents the suction operation from becoming impossible.

Therefore, conventionally, in this type of device, the distance between the brake shoe and the supply reel stand has been adjusted so that the brake arm can be rotated accurately against the spring during the remaining suction stroke of the suction rod, for example, 1 mm. However, in the past, the structure was such that it was difficult to easily and accurately adjust the distance.

In other words, conventionally a wire (thin metal rod) was used to connect the brake arm and the pinch roller crimping lever.
A roughly U-shaped curved section is formed in advance at the middle part of the wire in the length direction, and the length of the wire is reduced by pinching and tightening the curved section with radio pliers or the like. I adjusted it to make it shorter and made the above-mentioned interval adjustment. However, in such an adjustment structure, even if the curved part is bent with radio pliers, etc., the curved part tends to extend again due to the elasticity of the wire itself, that is, springback, so the amount of deflection with radio pliers, etc. is limited by the work. It is difficult to make accurate adjustments because the operator has to rely on the operator's intuition and has to be skilled. Also, if you inadvertently grip the radio pliers too tightly, causing the curved part to bend too strongly,
Subsequent adjustments to widen the curved portion were extremely troublesome. That is, while it is relatively easy to make adjustments in the direction of shortening the length of the wire, it is very troublesome to make adjustments in the direction of increasing the length of the wire. Furthermore, since the curved section formed at the middle of the wire is moved together with the wire, a space must be secured for the curved section to move, resulting in a poor space factor. In addition, during use, a load is constantly applied to the curved portion in the direction of expanding it, so the curved portion may be extended unexpectedly.
It is easy for errors in the gap to occur (the gap becomes smaller),
The need for readjustment arises.

The present invention was devised in view of the above-mentioned circumstances, and it is possible to extremely easily and accurately adjust the distance between the brake shoe and a rotating body such as a reel stand to which the brake shoe is crimped. Moreover, it is an attempt to provide an extremely simple structure.

An embodiment in which the present invention is applied to a soft brake device for a VTR will be described below with reference to the drawings.

First, in Fig. 1, the brake arm 1 is
It is rotatably supported on a mechanical board 7 (see FIG. 3) via a fulcrum shaft 2 . A brake shoe 3 is provided at the tip of the brake arm 1, and the brake shoe 3 is configured to be press-fitted to and detached from the circumferential surface 4a of the supply reel stand 4. The brake arm 1 is biased to rotate counterclockwise in the figure by a spring 6 stretched between a spring locking portion 5 provided on a mechanical board 7.

On the other hand, a pinch roller lever 9 is rotatably supported on a loading ring 8 rotatably provided on the mechanical board 7 via a fulcrum shaft 10.
A pinch roller 12 is rotatably supported on the tip of the pinch roller lever 9 via a support shaft 11. In addition, the pinch roller lever 9 has a spring 1.
3 in the clockwise direction in the figure, and the stopper 14 on the loading ring 8 restricts the rotation. Also, pinch roller 12
A tape pull-out guide 15 is provided on the loading ring 8 at the front position.

By the way, this FIG. 1 shows a state in which tape loading is completed, and at this time the pinch roller 12 is stopped at one side of the capstan 16 provided on the mechanical board 7. A pinch roller pressure lever 17 is provided on the mechanical board 7 at a position opposite to the capstan 16 of the pinch roller 12. In this case, the pinch roller pressure bonding lever 17 is composed of a first lever 17a and a second lever 17b that are rotatably supported in common on a fulcrum shaft 18 provided on the mechanical board 7. The first lever 17a is rotated counterclockwise in the figure by a spring 20 stretched between the spring locking portion 19 provided on the mechanical board 7, and the first lever 17a and the first lever 17a are rotated counterclockwise in the figure. A pinch roller pressure spring 21 is stretched between the two levers 17b. The tip of the first lever 17a is engaged with an annular groove 24 provided at the tip of a suction rod 23 of a small plunger solenoid 22 provided on the mechanical board 7. Note that both ends 26a and 26b of an operating member 26 made of a wire (a thin metal rod) are connected between the brake arm 1 and the first lever 17a.

According to the soft brake device configured as described above, first, during tape loading, the brake shoe 3 of the brake arm 1 is
is lightly pressed against the peripheral surface 4a of the supply reel stand by the spring force of the spring 6, and a brake is applied to the supply reel 4 to prevent the tape 27 from being fed out more than necessary. On the other hand, when the FWD button is pressed after tape loading is completed, the suction rod 23 of the plunger solenoid 22 is sucked and the pinch roller crimping lever 17 is sucked, as shown by the solid line in the figure.
The first lever 17a is rotated clockwise against the spring 20, the second lever 17b is rotated clockwise via the pinch roller pressure spring 21, and the second lever 17b causes the pinch roller 12 to be rotated. The tape 27 is pressed onto the capstan 16 by the pinch roller 12 . At this time, the brake arm 1 is moved to the spring 6 by the first lever 17a via the brake operating member 26.
The brake shoe 3 is rotated clockwise against the
is separated from the supply reel stand 4, and the brake of the supply reel stand 4 is released.

However, when levering, the suction stroke of the suction rod 23
If S ₁ is, for example, 4 mm, after the start of suction, the pinch roller ₁₂ is pressed against the capstan 16 with a stroke of 4 mm, and then with a final stroke of, for example, 1 mm.
At S ₃ , the brake shoe 3 is applied to the peripheral surface 4 of the supply reel stand 4.
The brake shoe 3 and the supply reel stand 4 when the brake arm 1 is rotated to the maximum clockwise by the brake operating member 26 so that the brake of the supply reel stand 4 can be released by separating from the brake shoe 3 and the supply reel stand 4. The distance g between is adjusted.

Next, the structure for adjusting the distance g will be explained with reference to FIGS. 2 and 3.

First, the brake arm 1 is molded from synthetic resin, and is rotatably attached to the first fulcrum shaft 2 by a boss portion 30 integrally molded on the lower surface of a portion thereof. A second fulcrum shaft 31 is integrally formed on the upper surface of the end of the boss portion 30 on the opposite side of the brake shoe 3 to the brake arm 1 . The brake arm 1 also has a second fulcrum shaft 31 on the upper surface of the end on the brake shoe 3 side.
An engaging portion 32 having an arc shape centered at is integrally molded. Note that this engaging portion 32 has a large number of teeth 32a having the tooth shape of a gear or a shape similar thereto. Also, the boss part 3 of this brake arm 1
An empty piece 33 is integrally formed on one side of the upper end of the brake arm 1 with a space between it and the upper surface of the brake arm 1. Further, a wave-shaped spring locking portion 34 is integrally formed near the second fulcrum shaft 31 of the brake arm 1, and one end of the spring 6 selects a locking position at the waveform portion. It is locked as much as possible. By selecting this locking position, the force exerted by the spring 6 to rotate the brake arm 1 in the counterclockwise direction, that is, the pressing force of the brake shoe 3 against the supply reel stand 4 can be adjusted.

Next, reference numeral 37 denotes an adjustment arm molded from synthetic resin, and this adjustment arm 37 has a through hole 38 provided approximately in the middle in the longitudinal direction of the adjustment arm 37.
It is sandwiched between the upper surface of the brake arm 1 and the protruding piece 33 while being fitted onto the fulcrum shaft 31 of the brake arm 1 . This adjustment arm 37 is connected to the second fulcrum shaft 3.
1 on the brake arm 1. At one end 37a of this adjustment arm 37, there is an elastic acting portion 3 having a substantially inverted U shape.
A locking portion 40 is integrally molded via 9. Note that this locking portion 40 has a plurality of teeth 40a that can selectively engage with a large number of teeth 32a of the engaging portion 32. The other end 37 of this adjustment arm 37
b has a long hole 41 substantially perpendicular to its longitudinal direction.
is provided, and one end 26a of the brake operating member 26 is locked in this elongated hole 41.

According to the structure for adjusting the distance g constructed as described above, the distance g can be easily and accurately adjusted in the following manner.

That is, first, use radio pliers etc. to adjust the adjustment arm 37.
By bending the elastic acting portion 39 by pinching it from the direction of the arrow in FIG. 3 against its elasticity,
The teeth 40a of the locking portion 40 are disengaged from the teeth 32a of the engaging portion 32. Next, after arbitrarily adjusting the rotation of the adjustment arm 37 with respect to the brake arm 1 around the second fulcrum shaft 31, the teeth 40a of the locking part 40 are moved to the engagement part 32 by the elastic repulsive force of the elastic acting part 39. tooth 32
a to again engage the adjustment arm 37 and the brake arm 1 together. As a result, the brake arm 1 is rotationally adjusted about the first fulcrum shaft 2 in relation to the brake operating member 26, and the distance g is adjusted. Moreover, at this time, after the above adjustment, brake arm 1 and adjustment arm 37
The teeth 32a and 40 of the engaging portion 32 and the locking portion 40
a are engaged with each other and are combined together, so after adjustment, these brake arms 1 and adjustment arms 3
There is no possibility that the above-mentioned distance g will be distorted due to unexpected rotation relative to 7. Further, since the above-mentioned adjustment can be performed by a so-called digital method by selectively engaging the teeth 32a and 40a, the adjustment is very simple and the adjustment is very easy.
The distance g can be adjusted accurately for each pitch of a. Furthermore, the brake device is composed of two parts: an adjustment arm 37 provided with an elastic locking portion 40 and a brake arm 1 provided with an engaging portion 32. Part 40
Since the above-mentioned distance g is adjusted by varying the engagement position of Unlike those that require dynamic adjustment, there is no need to use any separate parts such as adjustment screws, the structure is very simple, and the adjustment work can be performed extremely easily.

Next, FIGS. 4 and 5 show a modification of the elastic acting portion 39, and in this case, it is approximately U.
A letter-shaped elastic acting portion 39 is provided horizontally on one side of the adjustment arm 37, and a pair of protrusions 43a are provided on the upper surface of both sides of the base of the approximately U-shaped curved portion of the elastic acting portion 39. , 43b are molded as a pair. In this case, the locking part 40 can be disengaged from the engaging part 32 by pinching both protrusions 43a and 43b in the direction of the arrow in FIG. 5 using radio pliers or the like and bending the elastic acting part 39.

According to the present invention, for example, it is possible to construct the locking portion from a leaf spring or the like and attach it to the adjustment arm. However, as shown in the embodiment, if the brake arm 1 and the adjustment arm 37 are molded from synthetic resin and the engagement portion 32 and the locking portion 40 are molded integrally therewith, the manufacture and assembly of these will be extremely simple and low cost.

Furthermore, the structure, shape, etc. of the engaging part and the locking part according to the present invention are not limited to the embodiments, and modifications such as using an elastic body such as rubber for one or both of them are also possible. It is.

Furthermore, although the supply reel stand 4 is shown in the embodiment as the rotating body referred to in the present invention, the present invention is also applicable to brake devices for various types of rotating bodies other than the supply reel stand.

Further, in the embodiment, the adjustment arm 37 is rotatably attached to the second fulcrum shaft 31 provided on the brake arm 1, but the adjustment arm 37 can be adjusted, for example, to the outer periphery of the boss portion 30 integrally formed on the brake arm 1. It is also possible to configure the arm 37 to be relatively rotatable so that the adjustment arm 37 can be rotated around the same axis as the first fulcrum shaft 2.

As described above, the present invention allows the adjusting arm and the brake arm to be moved relative to each other by varying the engaging position of the elastic locking part provided on the adjusting arm with respect to the engaging part provided on the brake arm. Adjust the rotation to adjust the angle between the rotating body and the brake shoe.
Because it is structured so that the time can be adjusted,
It has the advantage that the adjustment can be made extremely easily and accurately, and the structure is extremely simple.

[Brief explanation of the drawing]

The drawings show an embodiment in which the present invention is applied to a soft brake device for a VTR.
The figure is a sectional view taken along the line shown in Fig. 2, Fig. 4 is a plan view similar to Fig. 2 showing a modified example, and Fig.
FIG. Further, in the symbols used in the drawings, 1...brake arm, 2...first fulcrum shaft, 3...brake shoe, 4...supply reel stand, 6...spring, 26...brake operating member, 31...Second
, 32...an engaging part, 37...an adjustment arm, 39...an elastic action part, and 40...a locking part.

Claims (1)

[Scope of utility model registration request] A brake arm is rotatably supported around a fulcrum and has a brake shoe at its tip, and the brake arm is rotatably supported around a fulcrum and has an elastic locking part at one end. driving the adjusting arm, an engaging portion formed in an arc shape centered on the fulcrum of the adjusting arm and engaged with the locking portion provided on the brake arm, and the other end side of the adjusting arm. and a brake operating member to adjust the relative rotation of the adjusting arm and the brake arm by varying the engaging position of the locking part with respect to the engaging part, and A brake device configured so that the gap between the brake shoe and a rotating body to which the brake shoe is crimped can be adjusted.