Door Mechanism of a Cassette Insertion Opening in an Audio Device

This invention relates to a door mechanism of a cassette insertion opening in a tape player, and more particularly to a door mechanism having double doors to improve hermetical sealing of the tape player so as to be suitable for use in a ship. etc.

Cassette type audio devices are widely used as car stereos and so forth. A prior art door mechanism of a cassette insertion opening in such an audio device has a single dust door pivotally supported at the opening. Such a dust door is made from a plastic resin, aluminum or other metals and shuts the cassette insertion opening when a cassette is not inserted therethrough to keep the interior of the audio device away from dust. When a cassette is inserted into the audio device, the dust door pivots a little inward into the audio device and remains there while the tape is driven.

Such cassette type audio devices are also used in ships and boats. Particularly, they are today in a considerable demand for small size leisure boats.

The prior art door mechanism, however, seals the audio device merely when a cassette is not inserted and remains halfway opened when the cassette is inserted. Therefore, the door cannot fully protect the interior of the audio device against water, salt and so forth and is not suitable for use in ships and boats.

It is therefore an object of the invention to provide a door mechanism capable of closing the cassette insertion opening also when a cassette is inserted.

Another object of the invention is to provide a door mechanism particularly suitable for use in ships and boats.

To achieve the objects, the door mechanism according to the invention includes double doors disposed inside and outside the cassette insertion opening.

FIG. 1 is a perspective view showing a door mechanism embodying the invention wherein the cassette insertion opening is closed;

FIG. 2 is a partly broken, perspective view of the door mechanism wherein the outer door is opened and the interior of the audio device is exposed;

FIG. 3 is a perspective view of the door mechanism wherein a cassette is on the way to or from the audio device; and

FIG. 4 is a perspective view of the door mechanism wherein a cassette is fully inserted in the audio device and the outer door is opened.

The invention will now be described in detail by way of a preferred embodiment shown in FIGS. 1 to 4.

First, the construction will be explained. An audio device 1 which is a stereo combined with a radio set includes a front panel 1a. The front panel 1a is formed with a transversely-long, rectangular opening 2 for inserting a cassette therethrough. The opening 2 is provided with a door mechanism D hereunder described in detail. An inner door shaft 3 extends along the upper, inner edge of the opening 2 and pivotally supports an inner door D.sub.2, while an outer door shaft 4 extends along the lower, inner edge of the opening 2 and pivotally supports an outer door D.sub.1. The outer door D.sub.1 has on the outer face thereof an indicator digitally indicating the radio frequency and is provided on the inner surface thereof with a packing member 5 made from sponge, for example. The packing member 5 forcibly contacts an outer wall 2a surrounding the cassette insertion opening 2 when the outer door D.sub.1 is closed. The outer door D.sub.1 is further formed along the upper edge thereof with depressions 6 for engagement with outer door lock arms which will be described later. An inner door wire spring S.sub.1 is mounted on the inner door shaft 3 to always bias the inner door D.sub.2 to a predetermined position where the inner door D.sub.2 contacts the inner wall of the front panel 1a around the opening 2 to close the same. Outer door wire springs S.sub.2 are mounted on the outer door shaft 4 to bias the outer door D.sub.1 to its open position. The inner door shaft 3 pivotally supports door lock members 7 to lock the outer door D.sub.1 at its closed position as shown in FIG. 1. Each said door lock member 7 consists of an outer door lock arm 7a projecting frontward of the audio device to lock the outer door D.sub.1, an unlocking arm 7b downwardly projecting and curving in the form of an arc encircling an unlocking portion 8 formed in the inner door D.sub.2, and a tongue 7c vertically extending from the rear end of the door lock member 7. The door lock members 7 are biased to their locking positions by wire springs S.sub.3 also mounted on the inner door shaft 3.

Behind and in parallel with the inner door shaft 3 is pivotally disposed an outer door rotating shaft 9 for opening and closing the outer door D.sub.1. One end (right end in FIG. 2) of the outer door rotating shaft 9 is connected to a button 10 for outer door opening operation. The outer door rotating shaft 9 has tongues 9a fixed thereto for engagement with the tongues 7c.

Next, the function of the door mechanism will be described hereunder.

In FIG. 1, the door mechanism D is closed. In this case, the packing member 5 forcibly contacts the outer wall 2a around the opening 2 and the outer door lock arms 7a engage the depressions 6 to lock the outer door D.sub.1 at the closed position. Thus, the interior of the audio device 1 is protected against the outer air and water.

Now assume that the outer and inner doors D.sub.1 and D.sub.2 are closed as shown in FIG. 1 and a user is going to insert a cassette C. When the button 10 is pushed, the tongues 9a are rotated in the clockwise direction in FIG. 2 and rotate the door lock members 7 in the counterclock direction to unlock the outer door D.sub.1. The outer door D.sub.1 is then rotated by the wire spring S.sub.2 to the open position of FIG. 2. Next, when the cassette C is inserted as shown in FIG. 3, the inner door D.sub.2 is pushed by the forefront of the cassette C and is rotated rearward. After the cassette is manually pushed to a predetermined position, it is automatically conveyed to the full extent in the audio device by a known cassette loading mechanism and is shifted down to the play position (FIG. 4). In this case, the inner door D.sub.2 remains halfway opened. When the outer door D.sub.1 is thereafter manually rotated in the counterclock direction to the full extent, it is locked at the close position by the door lock members 7a engaging the depressions 6. Thus, the interior of the audio device 1 is protected against the outer air and water also while the cassette C is loaded.

Now assume that a user is going to eject the cassette C. When an eject button (not shown) is operated, tape drive motion is stopped and said cassette loading mechanism operates in the reverse order to said loading operation. Namely, the cassette C is first raised to the height for ejection and rotates the inner door D.sub.2 in the clockwise (further inward) direction. Thereby, the unlocking portions 8 of the inner door D.sub.2 push the unlocking arms 7b to rotate the door lock members 7 in the counterclock direction so that the lock arms 7a disengage from the depressions 6 in the same manner as operated by the button 10. Then, the outer door D.sub.1 opens and the cassette C is concurrently automatically pushed back through the cassette insertion opening 2. After the cassette C is removed from the audio device, the outer door D.sub.1 is manually rotated so as to close the opening 2 as shown in FIG. 1.

The indicator on the outer door D.sub.1 may indicate any other data instead of the received frequency of the radio set in the audio device, or alternatively, the outer door D.sub.1 may be in the form a plain plate without such an indicator.

As described above, according to the invention, the door mechanism consists of the inner door and the outer door, the outer door being provided at the rear surface thereof with the packing member for forcibly contacting the wall surface around the cassette insertion opening, the door mechanism further comprising door lock means to lock the outer door in the closed state, the door lock means being operated to unlock the outer door by a manual operation of the door opening button or by an automatic opening rotation of the inner door caused by an ejecting operation. Therefore, the door mechanism fully protects the interior of the audio device against dust, salt and water any time when a cassette is loaded or not. Thus, the door mechanism is greatly suited to audio devices for use in ships and boats. Further, since both the inner and outer doors are automatically opened upon ejection of a cassette, the door mechanism does not spoil the simple handling of the audio device.