The present invention relates to a diving mask and more particularly to a diving mask having a drainage mechanism provided with a check valve.
Diving masks are well known which have a drainage mechanism provided with a check valve. For example, U.S. Pat. No. 5,890,234 (Reference 1) and U.S. Pat. No. 5,979,441 (Reference 2) disclose a diving mask comprising a nose cover formed integrally with a skirt member and an annular member attached to a bottom of the nose cover. The annular member includes a plurality of drain holes and a check valve adapted to be opened outward with respect to these drain holes. The check valve is normally held in close contact with a valve seat formed on the annular member. The annular member is previously formed using material different from material for the skirt member and set in a die when the skirt member is molded in this die so that the annular member may be integrated with the skirt member.
Conventionally, the annular member including the valve seat is formed using a plastic or metallic material is a relatively hard and deformation-resistant while the skirt member is formed using a soft and elastic rubber-like material. The annular member is provided with an annular projection having a height in a range of about 0.3 to about 0.5 mm serving as the valve seat. Generally, such annular member is set in the die used to mold the skirt member at a predetermined position of the die. Molten plastic material is injected at a high pressure into the closed die to obtain the skirt member including the nose cover integrated with the annular member. However, such a process of molding the skirt member may be often accompanied with a problem such that the molten plastic material flows to the annular member and partially covers the valve seat. Obviously, the valve seat should not be covered with the plastic material. The amount of the plastic material partially covering the valve seat in this manner refers to as flash and it is impossible to ensure that the check valve is normally held. in close contact with the valve seat so far as such flash is not removed.
In view of the problem as has been described above, it is an object of the present invention to improve the conventional diving mask having the drain holes provided with the check valve so that the close contact between the check valve and the valve seat may be easily and reliably obtained.
The object set forth above is achieved, according to the present invention, by an improvement in a diving mask having a back-and-forth direction, a transverse direction and a vertical direction being orthogonal one to another, and comprising: a lens unit including one or more lenses formed from a soft and transparent material and located ahead in the back-and-forth direction; a skirt member formed from a soft elastic material and extending rearward from the lens unit and a head-strap member adapted to hold a peripheral edge of the skirt member in close contact with the face of a wearer, the skirt member being formed in a region corresponding to a middle region of the lens unit as viewed in the transverse direction with a nose cover; and a drainage mechanism including a check valve adapted to be opened toward an outside of the skirt member being formed in a bottom of the nose cover or in a vicinity of the nose cover.
The improvement according to the present invention is as follows: The drainage mechanism comprises an inner annulation defining a through-hole adapted to receive a mounting shaft of the check valve, a plurality of drain holes defined around the inner annulation by a plurality of spokes radially extending from the inner annulation and a valve seat extending in a circumferential direction of the inner annulation outside an array of the drain holes and projecting toward the check valve. The valve seat is formed from an elastic material integrated with the soft elastic material forming the skirt member. An annular member formed from one of a plastic material and a metallic material having a hardness and deformation-resistance both higher than those of the elastic material forming the valve seat is embedded in the bottom of the nose cover in a vicinity of the valve seat so as to extending along the valve seat.
According to one preferred embodiment of the present invention, the inner annulation of the drainage mechanism has the through-hole formed from the same hard material as the material forming the annular member so that the hard material constituting the inner annulation is connected with the annular member by means of the hard material extending along the spokes.
In the diving mask according to the present invention, the valve seat cooperating with the check valve is formed from the elastic material which is integrated with the elastic material used for the skirt member. This unique arrangement reliably eliminates the possibility that the elastic material used to form the skirt member might cover the valve seat in the form of flash. Furthermore, the through-hole and the annular member of the drainage mechanism can be formed at once from the hard material by connecting such hard material constituting the inner annulation with the annular member formed from the hard material extending along the spokes.
Details of a diving mask according to the present invention will be more fully understood from the description given hereunder with reference to the accompanying drawings.
A diving mask 1 shown in
In the drainage mechanism 11 of the mask 1, the disco-lamina 21 of the check valve 16 is normally held from the outside in close contact with the valve seat 19 of the nose cover 8. To drain off an amount of water accumulated within the nose cover 8, a mask wearer may breathe hard through his or her nose to open the check valve outward. In the drainage mechanism 11 functioning in this manner, the disco-lamina 21 as well as the valve seat 19 of the check valve 16 are formed from the soft elastomer. However, the annular member 23 lying in close proximity to the valve seat 19 is sufficiently hard and deformation-resistant to prevent the valve seat 19 from being significantly deformed and to hold the valve seat 19 in contact with the check valve 16 as closely as the conventional valve seat often formed from a hard material has been the case. In addition, the drainage mechanism 11 according to the present invention is advantageously free from the problem that the valve seat 19 as a part of the annular member 23 might be covered with flash of the elastomer destined to form the nose cover 8 during injection molding of the skirt member 6. This is because that the present invention allows the nose cover 8 to be obtained without reliance upon the conventional process in which the annular member previously formed together with the valve seat by a relatively hard material is set in the die for molding the nose cover so that the annular member may be integrated with the nose cover.
While description has been made above with respect to the diving mask 1 of twin-lens type, the present invention may be exploited also in the form of a single eyed diving mask. While the illustrated diving mask 1 has the drainage mechanism 11 in the bottom 13 of the nose cover 8, the present invention may be exploited also in the form of a diving mask having the drainage mechanism 11 in any other region, for example, in the vicinity of the nose cover.
The present invention allows the diving mask ensuring the reliable close contact between the check valve and the valve seat for drainage to be easily produced.
Number | Date | Country | Kind |
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2004-99631 | Mar 2004 | JP | national |