JPS5912731Y2 - Air damper for cassette attachment/detachment device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an air damper for a cassette attachment/detachment device that is most suitable for application to tape recorders, VTRs, car stereos, and various other cassette type recording and reproducing devices.

A cassette loading/unloading device such as a tape recorder that is configured to insert a cassette into a cassette holder and use the cassette holder to load/unload the cassette is called a soft eject system, which reduces the movement resistance of the cassette holder when loading the cassette. Recently, the mainstream has become a lightweight and quick cassette loading device, and a cassette holder that increases the movement resistance when ejecting the cassette so that the cassette can be ejected slowly and quietly.

Incidentally, the air damper used in this type of soft eject system had the structure shown in FIGS. 1 and 2.

That is, a cylinder 2 into which a piston 1 is reciprocably inserted.
A valve 5 using a steel ball 4 is provided on the bottom wall 3 of the valve.

When the cassette is mounted, the piston 1 is moved in the direction of arrow A using a cassette holder (not shown) as shown in FIG. 1, and the valve 5 is pushed open by the internal pressure of the cylinder 2, thereby reducing the movement resistance of the cassette holder.

On the other hand, when discharging the force set, the piston 1 is moved in the direction of arrow B by the cassette holder as shown in FIG. 2, and the valve 5 is closed by vacuum suction, thereby increasing the movement resistance of the cassette holder.

However, in the air damper of the above-mentioned conventional structure, it is necessary to limit the fit between the piston 1 and the cylinder 2 to a diameter of 1 mm, and in order to stabilize the dimensions during molding,
Not only does it require a longer molding cycle, but it also requires matching model numbers.

Furthermore, the molding and assembly of the valve 5 using the steel balls 4 is troublesome, resulting in high costs.

Furthermore, when using the air damper in an installation position where the steel ball 4 is placed directly above the cylinder 2, the steel ball 4 can stably open and close the valve 5, but in other positions, the damper effect cannot be achieved. This makes it difficult for the air damper to be installed in one direction, which is inconvenient.

This invention was devised to correct the above-mentioned defects, is extremely low cost, and allows reliable damper operation at all times without being affected by the mounting orientation of the air damper. The present invention aims to provide an air damper for a cassette attachment/detachment device.

An embodiment in which the present invention is applied to a cassette tape recorder will be described below with reference to the drawings.

First, the cassette attachment/detachment device will be explained with reference to FIGS. 3 to 8.

First, reference numeral 11 is the front panel of the tape recorder main body, and an opening 12 is provided for attaching a cassette holder.

13 is a cassette holder that is detachably attached to the opening 12, and 14 is a cassette.

Note that both the front panel 11 and the cassette holder 13 are molded from synthetic resin.

A pair of left and right cassette holding plates 15a and 15b are integrally formed on the back of the cassette holder 13.
The cassette 14 is inserted from above into a cassette storage section 16 provided between these cassette holding plates 15a, 15b and held therein.

Arc-shaped arms 17a and 17b are integrally formed at the lower ends of the two-force set holding plates 15a and 15b.

Further, a pair of left and right elastic plates 18a, 18b are integrally formed on the back of the cassette holder 13, and a pair of pins 19a,
19b is integrally molded.

On the other hand, at the lower edge 12a of the opening 12 and on the back side of the front panel 11, there are circumferential arc-shaped arms 17a, 1 of the cassette holder 13.
A pair of left and right holder fulcrum plates 20a, 20 facing 7b
b is integrally molded.

Both holder fulcrum plates 20a and 20b are provided with arcuate curved surfaces 21a and 21b, respectively.

Further, a closing wall 22 having a Paco-shaped cross section is integrally formed on the back surface of the front panel 11 opposite to the back surface of the opening 12.

Cutouts 23a and 23b for engagement with both pins 19a and 19b of the cassette holder 13 are provided in left and right side plates 22a and 22b of the closing wall 22, respectively.

Then, insert the cassette holder 13 into the opening 1 of the front panel 11.
When attaching the two parts, first attach the circumferential arcuate arms 17a and 17b to the lower edge 1 of the opening 12 as shown in FIGS.
2 a to the back side of the front panel 11, and the circumferential arc-shaped arms 17 a, 17 b are attached to both holder fulcrum plates 20.
a, 20b are engaged with the arcuate curved surfaces 21a, 21b.

At this time, the lower end 13a of the cassette holder 13 is brought into contact with the front surface of the front panel 11.

Both holder fulcrum plates 20a and 20b are inserted between the lower end 13a and the circumferential arc arms 17a and 17b,
The cassette holder 13 has both arcuate curved surfaces 21 a, 21
It can be freely rotated along b.

Then, the cassette holder 13 is rotated counterclockwise in FIG. 7, and both elastic plates 18a and 18b are bent inward against their elasticity, as shown by imaginary lines in FIG. Both pins 19a, 19b (7) are inserted into the inside of the front panel 11 from the left and right edges 12b, 12C of the opening 12.

After this insertion, when both elastic plates 18a and 18b are elastically returned to their original parallel state as shown by solid lines in FIG.
a.

23b, so that the cassette holder 13 will not fall off from the front panel 11 thereafter.

As a result, the cassette holder 13 is attached to the front panel 11 so as to be rotatable within the angle .theta. shown in FIG.

When removing the cassette holder 13 from the front panel 11, the installation described above can be done in the reverse order, but when it comes to installing and removing the cassette holder 13, it is necessary to hold both elastic plates 18a and 18b against their elasticity. The main operation is to bend the pins 19a and 19b inward and insert or remove the pins 19a and 19b into the notches 23a and 23b, and attachment and detachment of the cassette holder 13 is extremely simple.

A pair of reel shafts 24a, 24b, a cassette positioning pin (not shown), etc. are provided on the front surface of the closing wall 22, as shown in FIG. 3, and a cassette holder is provided as shown in FIG. After inserting the cassette 14 into the cassette storage section 16 of No. 13, push in the cassette holder 13 and rotate it counterclockwise.
4 is inserted into the opening 12, becomes vertical as shown by the imaginary line in FIG. 4, and is attached to both reel shafts 24a, 24b, etc.

Also, upon completion of this cassette installation, the cassette holder 13
The opening 12 is closed.

At this time, as shown in FIG. 5, one side of the opening 12 is rotatably attached to the back of the front panel 11 via a fulcrum shaft 25, and is rotated clockwise in FIG. 5 by a spring 26. A dynamically energized lock lever 27 comes into contact with a slope 28 provided on one side of the cassette holder 13.

Then, guided by this slope 28, the lock lever 27
is rotated counterclockwise against the spring 26 as shown by the imaginary line in FIG. 5, and slides up the slope 28.

At the same time as the cassette installation is completed, the lock lever 27 is engaged in the recess 29 of the cassette holder 13 provided following the slope 28 as shown by the imaginary line in FIG. 4, and the cassette holder 13 is locked.

On the other hand, when the eject button (not shown) is pressed when ejecting the force set, the lock lever 27 is rotated by the interlocking lever 30 as shown in the imaginary line in FIG. 5 against the spring 26, and the lock lever -27 is removed from the recess 29.

Then, the lock of the cassette holder 13 is released, and the cassette holder 13 is slowly and quietly rotated clockwise in FIG. 4 by a damper operation by an air damper, which will be described later, and the cassette 14 is ejected.

Next, the mounting structure of the air damper 32 will be explained with reference to FIGS. 4 to 7 and FIG. 11.

First, a damper mounting plate 33 made of synthetic resin is removably screwed to the back surface of the front panel 11 on one side of the frontage 12 using a pair of screws 34.

The cylinder 35 of the air damper 32 is mounted on the damper mounting plate 33 in a vertically downward direction.

The piston 36 of the air damper 32 is connected to the cylinder 3.
It protrudes vertically upward above 5.

The cylinder 35 is integrally molded on a part of its outer periphery and has a T-shaped projection 37 that is fitted into the lock (L38) on the damper mounting plate 33 and can be attached and detached. Installed.

In addition, the fulcrum shaft 3 whose bottom is integrally formed with the damper mounting plate 33
An interlocking lever 40 having a square shape is rotatably attached to the lever 9 .

A pin 41 integrally formed at the tip of one arm 40 a of the interlocking lever 40 is engaged with a long hole 42 provided at the upper end of the piston 36 .

Further, the pin 19a of one elastic plate 18a of the cassette holder 13 is engaged in the elongated hole 43 provided at the tip of the other arm 40b of the interlocking lever 40, and the pin 19a of the elastic plate 18a of the cassette holder 13 is engaged. The piston 36 and the cassette holder 13 are interlocked.

Further, a spring 44 is fitted into the fulcrum shaft 39, one end 44a of the spring 44 is locked to the arm 40a of the interlocking lever 40, and the other end 44b is locked to the damper mounting plate 33. The interlocking lever 40 is urged to rotate counterclockwise in FIG. 7 by this spring foot.

As a result, a clockwise rotational force is applied to the cassette holder 13 via the interlocking lever 40 in FIG.

Further, the interlocking lever 40 is fixed by a retaining ring 45 fitted to the tip of the fulcrum shaft 39.

Therefore, before the cassette mounting operation is started, the cassette holder 13 is rotated clockwise by the spring 44 as shown in FIG. 7 and is in the open state.

When the cassette is mounted in this state, as the cassette holder 13 is pushed in the counterclockwise direction as shown in FIG. Rotated clockwise in Figure 7,
Further, the piston 36 is moved downward through the pin 41 and the elongated hole 42 and inserted into the cylinder 35, and the cassette holder 13 is brought into a closed state.

Note that when this cassette is installed, the air damper 32 does not perform any damping operation.

Therefore, at this time, the movement resistance of the cassette holder 13 is small, and the cassette holder 13 can be simply pushed in against the spring 44, and the cassette mounting operation can be performed easily and quickly.

On the other hand, when the cassette is ejected as described above, the cassette holder 13 is automatically rotated clockwise in FIG. 7 by the pushing force of the interlocking lever 40 counterclockwise in FIG. 7 by the spring 44 to the open state.

When the cassette is ejected, the piston 36 is pulled upward in the cylinder 35 by the interlocking lever 40, and at this time the air damper 32 performs a damping operation as described later.

As a result, the movement resistance of the piston 36 increases, and the spring 4
4 is extremely weakened, and the cassette holder 13 is moved slowly and quietly.

Next, the detailed structure of the air damper 32 will be explained with reference to FIGS. 9 to 12.

First, both the cylinder 35 and the piston 36 are made of synthetic resin.

A small hole 52 is provided in the bottom wall 51 of the cylinder 35.

Note that this small hole 52 has a diameter of, for example, about 0.1 mm.

Further, the piston 36 is inserted into the cylinder 35 with a sufficient clearance so as to be able to reciprocate.

A pair of flange portions 53 are provided on the outer periphery of the tip (lower end) side of the piston 36 at a predetermined interval in the axial direction.
54 is integrally molded.

An annular groove 55 is formed between these flange portions 53 and 54.

An O-ring 56, which constitutes an example of an elastic ring in the present invention, is inserted into the annular groove 55.

Note that this O-ring 56 is attached to the inner peripheral surface 57 inside the cylinder 39.
It is lightly press-fitted into.

Further, the groove width l of the annular groove 55 in the longitudinal direction of the piston is configured to be sufficiently larger than the thickness t of the O-ring 56, and the O-ring 56 is configured to be able to move within the annular groove 55 in the longitudinal direction of the piston. There is.

Further, the groove bottom circumferential surface 59 of the annular groove 55 is configured in a conical shape such that the diameter is large on one flange portion 53 side, which is the lower end side, and the diameter is small on the other flange portion 54 side, which is the upper end side. .

When the O-ring 56 is biased toward one flange portion 53 in the annular groove 55 as shown in FIG.
The J-ring 56 is lightly press-fitted into the larger diameter side of the groove bottom peripheral surface 59, and when the O-ring 56 is biased toward the other flange portion 54 within the annular groove 55 as shown in FIG. A gap 60 is formed between the O-ring 56 and the smaller diameter side of the groove bottom peripheral surface 59.

Note that a plurality of radial ribs 61 are integrally molded on the lower surface 54a of the other flange portion 54.
As shown in the figure, when the O-ring 56 is biased toward the flange portion 54, the rib 61 pushes the O-ring against the lower surface 54a.
The structure is such that the ring 56 is suspended and a gap 62 is created between them.

According to the air damper 32 configured as described above, when the piston 36 is inserted downward into the cylinder 35 by the cassette holder 13 as shown in FIG. inside, it is biased toward the other flange portion 54 side.

As a result, the air in the cylinder 35 escapes to the outside not only through the small hole 52 but also around the piston 36 through the gaps 60, 62, and the piston 36 is inserted into the cylinder 35 lightly and quickly.

Therefore, when the cassette is attached, the air damper 32 does not perform any damping operation.

On the other hand, when the cassette is ejected as described above, when the piston 36 is pulled upward in the cylinder 35 by the spring action as shown in FIG.

As a result, the O-ring 56 is lightly press-fitted into the inner circumferential surface 57 of the cylinder 35 and the groove bottom circumferential surface 59 of the annular groove 55, and air circulation around the piston 36 is completely blocked. In this state, the piston 36 is pulled upward within the cylinder 35.

At this time, external air is sucked into the cylinder 35 only through the small hole 52 due to the air suction action of the piston 36, and a large load is applied to the piston 36 due to the air inflow resistance at the small hole 52, causing its movement. resistance increases.

Therefore, when the cassette is ejected, the air damper 32 performs a damping action, the force of the spring force is extremely weakened, the piston 36 is gradually pulled up inside the cylinder 35, and the cassette holder 13 is opened slowly and quietly.

The effectiveness of the damper can be controlled by changing the diameter of the small hole 52.

Moreover, according to the air damper 32 having the structure as described above, the above-described damper operation can always be performed reliably, regardless of its mounting orientation.

Further, the dimensional tolerance of this air damper 32 is approximately ±0.1 mm, which is sufficient.

Next, FIG. 13 shows a modification of the piston 36, in which the other flange portion 54 is removed and a plurality of rib plates 64 provided along the longitudinal direction of the piston 36 are removed. The O-ring 56 is configured to receive the opposite side of the O-ring 56 from the one flange portion 53 at the end surface 64a.

As described above, the present invention switches the air flow around the piston to open or close by biasing the elastic ring in the annular groove of the piston in a direction opposite to the direction of movement of the piston, and in conjunction with this switching, Since the damper operation is performed by reducing or increasing the movement resistance of the piston, there is no need to increase the molding accuracy as in the prior art.

Therefore, not only can it be sufficiently molded in a normal molding cycle, but also JIS standard O-rings can be used as elastic rings, so there is no need to match model numbers, etc., and molding and assembly are extremely simple and extremely low-cost. You can get something.

Moreover, there is an advantage that the damper can always operate reliably without being affected by the mounting orientation of the air damper.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of a conventional example. Figures 3 to 13 show an embodiment in which the present invention is applied to a cassette tape recorder. Figure 3 is an exploded perspective view of the cassette holder and front panel, and Figure 4 shows the cassette holder. Cross-sectional view of the device installed on the front panel,
Figure 5 is a view of Figure 4 ■-V line arrow, Figure 6 is Figure 4 VI-
VI line arrow view, Fig. 7 is a sectional view taken along the line Vll-Vll in Fig. 6, Fig. 8 is a sectional view taken along the line ■1-■ in Fig. 6, Figs. 9 and 10.
The figure is a sectional view explaining the operation of the air damper, Figure 11 is an exploded perspective view of the air damper mounting structure, Figure 12 is a perspective view of the piston, and Figure 13 is a perspective view showing a modification of the piston. be. In addition, in the symbols used in the drawings, 13...cassette holder, 14...cassette, 32...air damper 35...cylinder, 36...piston, 40
... Interlocking lever, shaver ... Spring, 51 ... Bottom wall of cylinder, 52 ... Small hole, 53° 54 ... Flange part, 55 ... Annular groove, 56 ... O-ring , 57...
・Inner circumferential surface of cylinder, 59...Groove bottom circumferential surface, 60...
・It is a gap.

Claims (1)

[Scope of utility model registration request] A cylinder having a small hole in the bottom wall, a piston inserted into the cylinder so as to be able to reciprocate with sufficient clearance, and an annular structure provided in the piston,
and an elastic ring that is lightly press-fitted into the inner circumferential surface of the cylinder, and the groove width of the annular groove is configured to be sufficiently large so that the elastic ring can move in the longitudinal direction of the piston within the annular structure. When the elastic ring is biased to one side in the longitudinal direction of the piston within this annular groove, the elastic ring is lightly press-fitted into the groove bottom circumferential surface of the annular groove, and in this annular structure, the elastic ring is biased toward one side in the longitudinal direction of the piston. A cassette attachment/detachment device configured such that the diameter of the groove bottom of the annular groove varies in the longitudinal direction of the piston so that a gap is created between the elastic ring and the circumferential surface of the groove bottom of the annular groove when the elastic ring is biased in the other direction. air damper