JPH0348739Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a reel brake device for a video tape recorder, and more specifically, it is operated by a solenoid and the bottom of a reel table installed on the top of a reel shaft. This relates to a reel brake device for a video tape recorder, in which a brake ring and a bullet holder that are activated by the elevation of the movable iron core are arranged between the lower movable iron core and the rotation of the reel table is controlled. It is.

Generally used video tape recorders (hereinafter referred to as VTRs) have a function that applies appropriate operation to the reel table and stops the rotation of the reel table by converting the function mode (MODE) of the VTR. A rail brake device is provided.

[Conventional technology]

As shown in FIG. 5, the conventional reel brake device has a solenoid 3' installed on a deck board 2' below a reel table 1', and generates electricity from an iron core 4' of the solenoid 3'. The movable iron core 6' inserted into the upper part of the reel shaft 5' is pulled downward by the magnetic force, and as the brake plate 7', which is integrally interlocked with the movable iron core 6', moves downward, the brake is applied. Rotation of the reel table 1' is stopped by contacting pieces 7'a formed radially on the outer side of the plate 7' and contacting pieces 1'a formed on the inner circumferential wall of the reel table 1'. It was configured to do so.

[Problem that the invention attempts to solve]

In the conventional reel brake device as described above, a movable iron core 6' and a core iron core 4' are installed above and below a reel shaft 5', respectively, and a brake plate 7' is installed on the inner peripheral wall of the reel table 1'. Several contact pieces 1'a that are in opposing contact with each contact piece 7'a are formed integrally with the reel table 1', and a brake plate is fixed to the upper end of the movable iron core 6'. 7' and the lower solenoid 3', a coil spring 8' must be installed to restore the movable iron core 6' and the brake plate 7' upward, resulting in a complicated configuration. The number of required parts increases and assembly is not easy.
There was a problem of rising product costs.

[Means for solving problems]

The present invention provides a reel brake device that can solve the above problems. In the reel brake device according to the present invention, a disc-shaped support plate is inserted and fixed to the upper part of the reel shaft exposed in the lower space of the reel table, and the lower part of the reel shaft is attached to the upper surface of the deck board. A movable iron core is inserted which is actuated by the drive of a fixed solenoid. A center portion of an inverted conical elastic holder is fixed to the upper end of the movable iron core, and an outer peripheral edge of the elastic holder having a smooth surface is supported in contact with an outer periphery of the bottom surface of the support plate. The elastic holder has one side cut out in the radial direction and is compressively deformed as the movable iron core moves upward.

A brake ring with one side cut out is disposed on the outer peripheral edges of the support plate and the reel holding device that are in contact with each other, and the friction plate attached to the outer peripheral edge of the brake ring and the inner peripheral wall of the reel table are connected to each other. A constant width interval is provided between them.

[Effect]

The brake device of the present invention configured as described above compresses the bullet holding tool by the upward movement of the movable iron core operated by the drive of the solenoid.
As a result, the elastic holding tool that is expanded and deformed causes the brake ring disposed at the end to expand outward, so that the friction plate attached to the outer circumferential wall of the brake ring comes into contact with the inner circumferential wall of the reel brake. hand,
The braking action of the rotating reel brake is now performed.

Therefore, the reel brake device of the present invention eliminates the use of a fixed iron core for raising the movable iron core and a coil spring for lowering and restoring the raised movable iron core. Since there is no need to provide another contact plate, there is an advantage that the reel brake device can be simplified.

Further, according to the reel brake device of the present invention as described above, the entire outer peripheral edge of the friction plate attached to the brake ring is pressed against the inner peripheral wall of the reel table due to the compression action of the holding tool due to the upward movement of the movable iron core. Since the entire area is contacted instantly, the rotation of the reel table can be quickly controlled. Furthermore, since a uniform frictional force is applied to the contact portion between the friction plate attached to the brake ring and the inner circumferential wall of the reel table, control efficiency is improved.

〔Example〕

Examples of the present invention will be described below. As shown in FIG. 1, a reel table 3 is rotatably supported above a reel shaft 2 erected on a deck board 1 via upper and lower ball bearings 4, 4'. A disc-shaped support plate 7 is provided in the middle of the reel shaft 2.
is press-fitted and fixed, and the center shaft support 7a of the support plate 7 is supported by the bottom surface of the lower ball bearing 4', and the outer peripheral edge of the support plate 7 and the inner wall 3a of the reel table 3 are connected to each other.
and between the top surface of the support plate 7 and the bottom surface of the reel table 3, respectively.

In the lower part of the support plate 7, an inverted conical retainer 8 as shown in FIG. 4 is inserted into the reel shaft 2. An outwardly bent plane portion (hereinafter referred to as an outwardly bent plane portion 8) formed on the outer peripheral edge of the upper end of the elastic holder 8
a) has almost the same size as the outer diameter of the support plate 7 and is in contact with the bottom surface of the support plate 7. A push plate 9 having the same size as the diameter of the movable iron core 5 is provided on the bottom surface of the inwardly bent plane part (hereinafter referred to as the inward plane part 8b) formed in the reel shaft insertion part at the lower end of the elastic holder 8.
are joined, and the bottom surface of the push plate 9 is supported in contact with the top surface of the movable iron core 5.

One side of the bullet holder 8 installed in this way has one side of the inner and outer flat parts 8a and 8b and the flat part 8.
A cutout 8d is formed in the radial direction of the elastic support 8 through one side of the inclined side wall 8c located between the elastic support 8a and 8b, and is actuated from the top or bottom of the elastic support 8. The elastic holder 8 is expanded outwardly and deformed by the pressing force.

In addition, as shown in FIG. 3, the gap formed between the outer peripheral edge of the support plate 7 and the elastic support 8 that are installed in contact with each other as described above and the inner wall 3a of the reel table 3 is provided with a gap as shown in FIG. , an annular brake (hereinafter referred to as brake ring 10) is inserted, and in the recess 10b formed between the upper and lower bent support pieces 10a and 10'a of the brake ring 10, there are supports that are in contact with each other. Outer peripheral edge of plate 7 and outward flat surface 8a of elastic holder 8
are inserted together. The brake ring 10
A friction plate 10c is attached to the outer peripheral wall of the reel table 3, and a constant distance is maintained between the friction plate 10c and the inner wall 3a of the reel table 3.

A cutout 10d similar to the cutout 8d formed in the elastic holder 8 is formed on one side of the brake ring 10 installed in this manner, and the elastic holder 8 is expanded outwardly as described above. The brake ring 10 is expanded and deformed together with the deformation of the brake ring 10.

To explain the operation of the reel brake device of the video tape recorder configured as described above, the first
The figure shows a state in which the reel table 3 is freely rotating when no braking force is applied to it. Since the above-described constant gap is maintained between the table 3 and the inner wall 3a, the reel table 3 can freely rotate.

When converting the functional mode of a VTR in such a state, when an electrical signal is applied to the solenoid coil 6 to apply braking force to the rotating reel table 3, the magnetic force generated in the solenoid coil 6 The movable iron core 5 is now moved upward, and as shown in FIG. is crimped upward by the movable iron core 5, and the incision 8d formed on one side of the elastic holder 8 is opened by the crimping force, so that the outer diameter of the elastic holder 8 is changed as a whole. As a result, the brake ring 10 that is in contact with the outer peripheral edge of the outwardly facing flat portion 8a receives an outwardly expanding force by the resilient tool 8, and the cutout portion 10d of the brake ring 10 is opened. . As a result, the friction plate 10c attached to the outer circumferential wall of the brake ring 10 is pressed against the inner wall 3a of the reel table 3, and the rotation of the reel table is controlled by the frictional force at the time of the press.

After that, when the solenoid 6 is demagnetized, the movable iron core 5, which had been raised, descends, and the brake ring 1
The open incisions 10d and 8d are closed by the elasticity of the elastic member 8 and the elastic member 8 itself, and the elastic member 8 is restored to the state shown in FIG. Therefore, the controlled state of the reel table 3 is released and the reel table can rotate freely.

[Effect of idea]

The reel brake device for a video tape recorder according to the present invention includes a simple structure of a holding tool and a brake ring interposed between a reel table and a movable iron core of a solenoid, and a solenoid formed on the holding tool and the brake ring. The cutout allows the braking and restoring operations of the reel table to be performed smoothly without the need for a separate restoring spring, which reduces manufacturing costs by reducing the number of parts and reduces the brake structure. This simplifies the assembly of the product, and also improves braking efficiency.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of a reel brake device for a video tape recorder according to the present invention;
FIG. 2 is a longitudinal sectional view showing the plate of the reel brake device shown in FIG. 1, FIG. 3 is a perspective view showing an example of a brake ring applied to the device of the present invention, and FIG. FIG. 5 is a perspective view showing an example of a bullet holding tool, and FIG. 5 is a longitudinal cross-sectional view showing the configuration of a conventional reel brake device. In the figure, 2... Reel shaft, 3... Reel table, 3a... Inner peripheral wall, 5... Movable iron core, 6...
...Solenoid coil, 7... Support plate, 8... Elastic holding tool, 8a... Outward plane part, 8d... Cutting part, 10
...Brake ring, 10b...Concave portion, 10c...
...Friction plate, 10d...The incisions are shown, respectively.

Claims (1)

[Claims for Utility Model Registration] A reel table 3 is loosely attached to the upper part of a reel shaft 2 which is vertically inserted into the deck board, and the reel shaft 2
In the reel brake device for a video tape recorder, the reel brake device is equipped with a movable iron core 5 operated by the drive of a solenoid on the lower side of the reel table 3 in the middle part of the reel shaft 2.
A sloping side wall 8c of a conical bullet holder 8 has a disk-shaped support plate 7 fixed at a certain distance from the bottom surface and an inner circumferential wall of the movable iron core 5, and a central portion fixed to the upper end of the movable iron core 5. an outwardly facing flat part 8a is formed as an extension at the outer end of the reel table 3, the outwardly facing flat part 8a is brought into contact with the bottom surface of the support plate 7, and a cutout part 8d is formed on one side of the outwardly facing flat part 8a; A brake ring 10 is provided inside the inner circumferential wall of the brake ring 10, which has a recess 10b into which the mutually contacting end of the support plate 7 and the elastic support 8 is inserted.
A reel brake device for a video tape recorder, characterized in that a cutout 10d is formed on one side of the brake ring 10.