Underwater mask

Abstract

An underwater mask includes a frame, a transparent portion supported by the frame, a seal portion mounted on the frame and adapted to be positioned on a user's face, and a ventilation tube. The seal portion has a partition wall resting on the user's nose and forming upper and lower chambers, which communicate through a passage in the partition wall and a one-way valve to enable air to flow only from the upper to the lower chamber. The ventilation tube has separate channels providing communication between the upper and respectively the lower chamber and the outer environment, and a hub between tube and mask, fastened to the mask and connected to the tube by a joint, so that in a coupling position the hub and the tube are fastened, and in a releasing position the hub and the tube remain connected but the tube is free to swing.

The invention claimed is: 
     
         1 . A mask comprising:
 a frame;   a transparent portion supported by the frame;   a seal portion mounted on the frame and adapted to be positioned on a user's face; and   a ventilation tube, sealingly and detachably connected to a hub, the hub being integral with the mask and comprising passages communicating an inner compartment of the mask with the ventilation tube to supply breathing air and discharge expiratory air,   wherein the hub is connected to the ventilation tube by a joint having a coupling position, in which the hub and the tube are sealingly fastened to one another in an operating position, and a decoupling position, in which the ventilation tube and the hub are decoupled, in which the ventilation tube remains connected to the hub but is free to swing around an axis transversal to an axis of the ventilation tube or an axis of the hub, and   wherein a first element of the joint comprises a fin provided with a protuberance and a second element of the joint comprises a hollow to accommodate the fin, the hollow having a raised edge interfering with the protuberance of the fin to provide only for specified movements of the fin inside the hollow.   
     
     
         2 . The mask according to  claim 1 , wherein the raised edge operates as a cam path for the protuberance of the fin to enable both translatory and rotary movements of the fin. 
     
     
         3 . The mask according to  claim 1 , wherein the hollow has a zone without the raised edge in order to allow the fin to be inserted into the hollow. 
     
     
         4 . The mask according to  claim 3 , wherein the zone without the raised edge is placed on a free side of the hub opposite a hub side coupled to the mask, so that insertion of the fin into the hollow is allowed by a movement approaching to the mask along a direction essentially parallel to a median longitudinal axis of the mask. 
     
     
         5 . The mask according to  claim 1 , wherein the joint between the ventilation tube and the hub is a film joint, and wherein the film bridge is composed of a portion or branch of a fastening belt of the mask to the user's head. 
     
     
         6 . The mask according to  claim 1 , wherein the transparent portion has a polygonal shape with squared radiusing facets. 
     
     
         7 . The mask according to  claim 6 , wherein the transparent portion is divided into a central portion, in relief, having a planar development and a polygonal shape, which is radiused with a perimetric zone, adapted to couple with the frame by way of surfaces with tilted polygonal shape. 
     
     
         8 . The mask according to  claim 1 , wherein the seal portion comprises:
 a partition wall adapted to be sealingly rested on the user's nose, when the mask is worn, so as to form an upper chamber and a lower chamber, the lower chamber accommodating the user's nose and mouth, wherein the upper and the lower chambers communicate through a passage in the partition wall and through a one-way valve so that air can flow from the upper chamber to the lower chamber and not vice versa; and   the ventilation tube comprising at least two separate side channels providing communication between the upper chamber and respectively the lower chamber and an outer environment.   
     
     
         9 . The mask according to  claim 8 , wherein the hub has a plurality of openings for engagement of corresponding ducts, the plurality of openings providing communication between the lower chamber and the side channels of the ventilation tube, and wherein the corresponding ducts are connection tubes arranged outside of both the frame and the seal portion. 
     
     
         10 . The mask according to  claim 1 , wherein the film joint is an upper end member that fastens a fastening belt of the mask to the user's head, whereby the fastening end member has contemporaneously a function of fastening the fastening belt of the mask to the user's head and operates as an articulating material bridge between the ventilation tube and the hub.