Diving Mask

A structural improvement of a diving mask which consists of a main frame, a sub-frame, a lens and a skirt. Tenons are provided on the sub-frame, engaging mortises on the lens. A soft connecting edge is provided on the skirt, which is closely connected with a periphery of the lens. A rigid structure is established by the tenon jointing the sub-frame with the lens, and the connecting frame of the skirt is closely connected with periphery of the lens, when the main frame is connected with sub-frame. This construction allows the diving mask lens removal and keeps a stable connecting state after its assembly.

FIELD OF THE INVENTION
 The present invention relates to structural improvement of a diving mask,
 especially, to structural improvement of the assembly between the lens and
 the main frame, or sub-frame for a diving mask.
 BACKGROUND OF THE INVENTION
 The conventional manufacturing method of a diving mask, which is connecting
 the lens with materials such as plastics (silicone etc.) when in moulding,
 then connect to a main frame and skirt (as shown in FIG. 1), has at least
 the following disadvantages:
 1. The lens is damageable when removing or exchanging the lens having for
 different sighted degrees (such as nearsighted, farsighted, presbyopic . .
 . ) or because it is difficult to reassemble, as a result a leaking
 phenomenon occurs at the edge of the lens.
 2. The plastic is closely connected with the lens because the lens (or
 glass) is directly placed into the die cavity during injection. The
 thickness of glass due to tolerance is not easily controlled in a certain
 range, and because there are some problems relating to heat-expanding and
 cold-contracting during injection, which causes undesired breaking and a
 latent danger for the eyes of a user.
 SUMMARY OF THE INVENTION
 The object of the present invention is to provide a structure of a diving
 mask consisting of a main frame, a sub-frame, a lens and a skirt which can
 be removed or assembled in order to exchange the lens or process the lens,
 which has still a stable structure after assembly and does not cause
 damage of leakage.
 The technical solution embodying the above-mentioned object of the present
 invention is as below. The structural improvement of the diving mask which
 consists of a main frame, a sub-frame, a lens and a skirt, wherein there
 are fitting slots provided on the main frame and protrusions on the
 sub-frame. Tenons are provided on the sub-frame and mortises on the lens,
 and a soft connecting edge is provided on the skirt which can be closely
 connected with the periphery of lens. A rigid structure is established by
 means of the tenon jointing the sub-frame with the lens, the connecting
 frame of the skirt is closely connected with the periphery of the lens
 when the main frame is connected with the sub-frame. The above-mentioned
 construction allows the diving mask removal and keeps still a stable
 connecting state after its assembly. The mortises on the lens and the
 tenons on the sub-frame can be connected to each other, the quantity and
 positions of mortises provided on the lens and tenons provided on the
 sub-frame can be 1.about.10 groups.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
 An exploded view for the structure of a conventional diving mask is a shown
 in FIG. 1, wherein the periphery of lens 1' forms sub-frame 2' by fixing a
 plastic water-proof layer, and then is connected with main frame 3' and
 skirt 4'.
 The structure of the present invention is as shown in FIGS. 2, 3, 4, its
 construction includes mainly a main frame 10, a sub-frame 20, a lens 30
 and a skirt 40.
 The main frame 10 and sub-frame 20 are connected by way of fitting slots 11
 and protrusions 21 engaging each other. The lens 30 is placed into
 sub-frame 20, the main frame 10 and skirt 40 can be integrated by means of
 connecting main frame 10 and sub-frame 20.
 There are tenons 22 provided on the sub-frame 20, which are fitted with
 mortises 31 provided on the lens 30. The position and quantity of tenons
 22 and mortises 31 which are fitted each other, may be varied according to
 the practical needs and configurations of the frame. One group to ten
 groups can be provided, in order to establish rigid connection between the
 elements, that is not easily deformed between sub-frame 20 and lens 30 due
 to external forces, and cause relative displacement or separation thereof.
 The skirt 40 is conventional, and is made of rubbery materials (or soft
 silicone). The frame edge 41 of skirt 40 can be connected with frame body
 12 of main frame 10 by a mode of deformation (ref. to FIG. 4).
 The contacting position of skirt 40 and lens 30 is the connecting frame 42
 in which the lens 30 can be placed in a close fitting state.
 The tenons 22 are connected with mortises 31, when the main frame 10 and
 skirt 40 are connected, the lens 30 is placed into connecting frame 42,
 and the main frame 10 with sub-frame 20 are pressed by means of slot 11
 and protrusion 1, forming a connected state. At this time, the sub-frame
 20 can make only a relatively sight deformation because the sub-frame 20
 with the lens 30 are in a rigid connected state due to connecting tenons
 22 and mortises 31.
 The joint of the connecting frame 42 with lens 30 is subjected to the
 pressure between main frame 10 and sub-frame 20, which forms a close
 fitting state between the connecting frame 42 and lens 30. Water cannot
 enter into the inside of skirt 40 through the gap between both elements
 under this state.
 In summary, after assembling the elements of the present invention, it has
 a structural state which is not deformable and is leakless. In addition,
 the structure of the present invention can be disassembled by separating
 the protrusions 21 and slots 11 in order to process or exchange lens 30,
 and such elements can be easily reassembled.
 The present invention forms a rigid connection between sub-frame 20 and
 lens 30. The foregoing description is provided for illustrative purposes
 only. The scope of the present invention is defined solely by the appended
 claims.