JPH0222827Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is used in cassette-type tape recorders, etc., to reduce the movement resistance of the cassette holder when loading the cassette, allowing light and quick loading of the cassette, and to reduce the movement of the cassette holder when the cassette is ejected. The present invention relates to an air damper for use in a so-called soft eject type cassette attachment/detachment device, which has a large movement resistance so that cassettes can be ejected slowly and quietly.

[Conventional technology]

In a conventional air damper for a cassette attaching/detaching device, as shown in FIG. 1, an O-ring is used as an elastic ring 19' that is loosely fitted into an annular groove 17' formed at the insertion end of a piston 11'.

[The problem that the idea aims to solve]

By the way, O-rings are individually shaped to a predetermined shape.
Since it is formed by polishing, the manufacturing process is complicated and it is quite expensive.Moreover, products with non-standard dimensions are even more expensive and practically difficult to obtain.

For this reason, the cost of the air damper for the cassette attachment/detachment device is high, and the actual cylinder size is limited by the size of the O-ring.

The present invention was made with the above-mentioned considerations in mind, and its purpose is to be inexpensive and to
It is an object of the present invention to provide an air damper for a cassette attaching/detaching device with good airtightness in a cylinder chamber.

[Means to solve the problem]

In order to achieve the above object, the air damper for a cassette attachment/detachment device according to the present invention includes a cylinder, first and second flange portions at the distal end, and these first and second flange portions.
an annular groove formed between the second flange portions, the first and second flange portions have an outer diameter with a sufficient clearance between them and the inner peripheral surface of the cylinder, and the piston protrudes. The second flange portion on the side includes a piston for inserting into the cylinder, which is partially formed with a notch, and has a thickness smaller than the width of the annular groove, and an outer diameter of which is in close contact with the inner circumferential surface of the cylinder. , and is formed to be slidable, and has an inner diameter larger than the bottom diameter of the annular groove and smaller than the outer diameter of the first and second flange parts, and the first and second flanges and an angular elastic ring for fitting into the annular groove, both of which are formed in a planar shape on both sides facing the part and a part facing the inner peripheral surface of the cylinder, so that the piston can be pulled out of the cylinder. When the square elastic ring is inserted into the cylinder, the surface of the square elastic ring facing the first flange comes into close contact with the first flange, preventing air from flowing into the cylinder from the piston insertion port side, and preventing the piston from entering the cylinder. When the square elastic ring is inserted into the cylinder, the surface of the square elastic ring facing the second flange portion does not close the entire notch even though it comes into close contact with the second flange portion. , is characterized in that it is configured to allow air to flow out from the inside of the cylinder to the piston insertion port side.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 2 shows a cassette attaching/detaching device in a cassette type tape recorder. In this figure, 1 is the front panel of the tape recorder main body, and 2 is an opening formed in this front panel 1 for attaching a cassette holder. Reference numeral 3 denotes a cassette holder that holds the cassette 4 in a freely insertable and removable manner. It is pivotally supported to be able to freely swing between the collapsed open state and is biased to swing toward the open state by a spring 6. Numeral 7 is a lock portion provided on the cassette holder 3, and 8 is a lock lever that engages and disengages from the lock portion 7, and is pivotally supported on a shaft 9 provided on the tape recorder main body.

A is an air damper according to the present invention, and its cylinder 10 is attached to the tape recorder body, and its piston 11 is attached to the cassette holder 3. Therefore, when a cassette is installed, by pushing the cassette holder 3 from the open state to the closed state against the biasing force of the spring 6, the lock lever 8 engages with the lock portion 7 and brings the cassette holder 3 into the closed state. . On the other hand, when ejecting a cassette, when an eject button (not shown) is pressed to disengage the lock lever 8 and the lock portion 7, the cassette holder 3 swings to the open state due to the biasing force of the spring 6; Since the swinging is affected by the damping effect of the air damper A, the cassette holder 3 swings slowly and quietly.

Next, the specific structure of the air damper A will be explained with reference to FIGS. 3 and 4.

A bottom wall 12 is integrally formed in the cylinder 10 near the opening at one end, and a small hole 1 is formed in the bottom wall 12.
3 is formed. Since this small hole 13 is not a micro hole for obtaining air inflow resistance, its inner diameter can be arbitrarily set in consideration of ease of molding and the like. A cylindrical portion 10 outside the bottom wall 12 of the cylinder 10 serves as an air suction path to the small hole 13.
A sealing member 14 and a spacer 15 made of a material with low air permeability, such as open-cell foam plastic or hard press felt, are inserted into the space a. The sealing member 14 may be simply press-fitted, or may be inserted after applying an adhesive to its peripheral surface.

On the other hand, the piston 11 is inserted into the cylinder 10 so as to be able to reciprocate with a sufficient gap between the piston 11 and the inner peripheral surface of the cylinder 10. A pair of first flange portions 16a and second flange portions 16b are integrally molded on the insertion end side of the piston 11 at a predetermined interval in the axial direction, and an annular groove 17 is formed between the two flange portions 16a and 16b. is formed. In addition, the second flange portion 1 on the piston protruding side
A notch 18 is formed in 6b.

A square elastic ring 19 having an appropriate diameter is fitted into the annular groove 17 so as to be freely movable in the axial direction of the piston 11 so as to be in close contact with the inner peripheral surface of the cylinder 10. The square elastic ring 19 is
It has a thickness smaller than the width of the annular groove 17, an outer diameter that is in close contact with the inner peripheral surface of the cylinder 10 and is slidable, an inner diameter that is larger than the bottom diameter of the annular groove 17, and both flanges. The outer diameter of the flange portions 16a, 16b is smaller than that of the flange portions 16a, 16b.
6b and a portion facing the inner circumferential surface of the cylinder 10 are both formed into a planar shape, and this square elastic ring 19 is biased toward the inner end in the axial direction of the piston 11 within the annular groove 17. In the positioned state, the square elastic ring 19 is in close contact with the first flange portion 16a of the piston 11, and the inside and outside of the square elastic ring 19 are sealed off in an airtight manner, and the square elastic ring 19 is deviated toward the outer end side of the piston 11 in the axial direction. In this state, although the square elastic ring 19 is in close contact with the second flange portion 16b, the notch 18 is not entirely closed, and the inside and outside of the square elastic ring 19 are configured to communicate through the notch.

Therefore, when the cassette is installed, the piston 11 is pushed and moved by the cassette holder 3 in the direction of the arrow shown in FIG. As a result, the air in the cylinder chamber S inside the piston 11 escapes from around the piston 11 to the outside through the notch 18, and no damper action is performed at all, so the piston 11 is lightly pushed into the cylinder 10. , and will be inserted quickly.

On the other hand, when ejecting the cassette, the cassette holder 3
As a result, the piston 11 is pulled in the direction of the arrow shown in FIG. As a result, the flow of air from around the piston 11 to the cylinder chamber S is blocked, and as the piston 11 moves, the pressure inside the cylinder chamber S is reduced, and external air permeates through the sealing member 14 due to atmospheric pressure. and cylinder chamber S
It gradually flows into the inside. This air inflow resistance at the seal member 14 applies a large load to the piston 11, causing the piston 11 to be moved at a low speed.

The square elastic ring 19 is made by punching out a commercially available vulcanized rubber sheet 20, as shown in FIG. 6, or by cutting a vulcanized rubber cylinder 21 into rounds, as shown in FIG. If necessary, it can be manufactured by a simple method such as polishing the cut surface, outer peripheral surface, etc., so it can be mass-produced and manufactured at low cost.
The dimensions and material can be freely selected according to the diameter of the cylinder 10. Moreover, since it comes into surface contact with the inner circumferential surface of the cylinder 10, the airtightness of the cylinder chamber S is improved.

Although not shown in the drawings, there are air dampers that use minute holes to obtain the air inflow resistance necessary for damper operation, as shown in Figure 1, and air dampers that provide air inflow resistance by providing small holes in the piston. It goes without saying that the square elastic ring 19 having the above structure can also be used in an air damper.

[Effect of idea]

As explained above, the air damper for a cassette attachment/detachment device according to the present invention has first and second flange portions on the cylinder and the tip portion, and an annular groove formed between the first and second flange portions. Then,
The first and second flange portions have outer diameters that have a sufficient clearance between them and the inner circumferential surface of the cylinder, and a notch is formed in a portion of the second flange portion on the piston protruding side. A piston for inserting the cylinder,
The cylinder has a thickness smaller than the width of the annular groove, an outer diameter that is in close contact with the inner circumferential surface of the cylinder and is slidable, and an inner diameter that is larger than the bottom diameter of the annular groove, and the third cylinder. 1. The outer diameter of the cylinder is smaller than the outer diameter of the second flange part, and both side parts facing the first and second flange parts and a part facing the inner circumferential surface of the cylinder are both formed into a planar shape. According to the present invention, there is a connection between the inner peripheral surface of the cylinder and the square elastic ring, and between the first and second flange parts and the square elastic ring. This improves the adhesion between the ring and the cylinder chamber, improving the airtightness of the cylinder chamber.
Since the square elastic ring can be manufactured by a simple method, it can be manufactured in large quantities at low cost, and
The dimensions and material can be freely selected according to the cylinder, and therefore, an air damper for a cassette attaching/detaching device having excellent performance can be obtained at a low cost.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional air damper. Figures 2 to 5 A and B show an embodiment of the present invention; Figure 2 is a sectional view showing an example of a cassette attachment/detaching device; Figure 3 is a sectional view of an air damper; and Figure 4 is an exploded perspective view thereof. 5A and 5B are operation explanatory diagrams. FIGS. 6 and 7 are perspective views each showing a method of manufacturing a square elastic ring. 10...Cylinder, 11...Piston, 16a
...First flange portion, 16b... Second flange portion, 17... Annular groove, 18... Notch, 19... Square elastic ring, A... Air damper.

Claims (1)

[Scope of utility model registration request] A cylinder 10, first and second flange parts 16a and 16b at the tip, and an annular groove 1 formed between these first and second flange parts 16a and 16b.
7, the first and second flange portions 1
6a and 16b have outer diameters with sufficient clearance between them and the inner peripheral surface of the cylinder 10, and the piston 11
The second flange portion 16b on the protruding side has a notch 18 formed in a part of the piston 11 for inserting the cylinder, and has a thickness smaller than the width of the annular groove 17 and an outer diameter of the cylinder 10. It is formed to be in close contact with the inner circumferential surface and to be slidable, and its inner diameter is larger than the bottom diameter of the annular groove 17 and smaller than the outer diameter of the first and second flange parts 16a and 16b. and a corner for fitting the annular groove 17 in which both side portions facing the first and second flange portions 16a, 16b and a portion facing the inner circumferential surface of the cylinder 10 are formed in a flat shape. When the piston 11 is pulled out of the cylinder 10, the first flange portion 16a of the square elastic ring 19
The surface facing the first flange portion 16a closely contacts the first flange portion 16a to prevent air from flowing into the cylinder 10 from the piston 11 insertion port side, and when the piston 11 is inserted into the cylinder 10, Although the surface of the square elastic ring 19 facing the second flange portion 16b is in close contact with the second flange portion 16b, the notch 18
An air damper for a cassette attaching/detaching device, characterized in that it is configured to allow air to flow from the inside of the cylinder 10 to the insertion port side of the piston 11 without blocking the entire part.