Pressure Reducing Second Stage for Underwater Use

Abstract

A pressure reducing second stage for underwater use includes a case provided with a breathing gas inlet, with an inhalation/exhalation port and with an exhaled gas exhaust outlet with a non-return valve, the gas inhalation/exhalation port being connected to a mouthpiece tube, the breathing gas inlet in the case being connected to a breathing gas pressure reducing device provided with a hollow cylindrical element or pipe, which has a breathing gas inlet port communicating with a gas supply conduit through a valve which is interposed between the supply conduit and the mouthpiece tube, the case being provided with a pressure sensitive means device for controlling the opening/closure of the valve. The breathing gas inlet in the case is provided in its lower portion and the hollow cylindrical element is connected to the inlet on the case such that its axis is substantially vertical, when used in the upright position.

The invention claimed is: 
     
         1 . A pressure reducing second stage ( 1 ) for underwater use comprising:
 a case ( 106 ) provided with a breathing gas inlet and with an inhalation/exhalation port through which breathing gas supplied into the case is inhaled by a user and through which the user supplies exhaled gas into the case, said case ( 106 ) being further provided with a first exhaled gas exhaust outlet having a non-return valve,   the inhalation/exhalation port being connected to an inhalation/exhalation mouthpiece tube ( 102 ) through which the breathing gas is inhaled by the user and through which the gas is exhaled into the case ( 106 ),   the breathing gas inlet in the case ( 106 ) being connected to a breathing gas pressure reducing device provided with a hollow cylindrical element ( 107 ), said hollow cylindrical element ( 107 ) having a breathing gas inlet port ( 117 ) communicating, through a valve, with a gas supply conduit ( 103 ), said valve being interposed between said supply conduit ( 103 ) and said inhalation/exhalation mouthpiece tube ( 102 ) for said breathing gas,   said case ( 106 ) being further provided with a pressure sensitive device that controls opening and closing of said valve,   wherein the breathing gas inlet in the case ( 106 ) is provided in a lower portion of said case ( 106 ), and   wherein a second stage ( 1 ) used by the user in an upright position and said hollow cylindrical element ( 107 ) of the pressure reducing device is connected to said inlet on the case ( 106 ) to have an axis that is vertical or substantially vertical, with reference to the upright position of the user, and substantially parallel to a longitudinal axis, or cranio-caudal axis, at an intersection of a sagittal plane with a coronal plane of the user's body;   further comprising a bypass tube ( 101 ), supplying said breathing gas from the pressure reducing device directly into the inhalation/exhalation mouthpiece tube ( 102 ), upon the opening of the valve, the bypass tube ( 101 ) being connected, at one end thereof, to a first port ( 112 ) provided on a shell wall of the hollow cylindrical element ( 107 ) of the pressure reducing device, and at an opposite end to a second port ( 112 ′) provided on a shell wall of the inhalation/exhalation mouthpiece tube ( 102 ).   
     
     
         2 . The pressure reducing second stage ( 1 ) according to  claim 1 , wherein said case ( 106 ) is provided with a second exhaled gas exhaust outlet ( 113 ) with a nonreturn valve ( 123 ), said first and said second exhaled gas exhaust outlets ( 113 ) being placed at sides of the breathing gas inlet in the case ( 106 ) connected to said hollow cylindrical element ( 107 ) of the pressure reducing device. 
     
     
         3 . The pressure reducing second stage ( 1 ) according to  claim 1  wherein in the inhalation/exhalation mouthpiece tube ( 102 ) there is provided a tongue ( 200 ) placed substantially diametrically with an orientation transverse to an axis of the bypass tube ( 101 ) and has an extension substantially parallel to an axis of said inhalation/exhalation mouthpiece tube ( 102 ). 
     
     
         4 . The pressure reducing second stage ( 1 ) according to  claim 3 , wherein said tongue ( 200 ) is provided substantially at a level coinciding with a central diametric position of the mouthpiece tube ( 102 ) or at an intermediate level between said central diametric position and an upper semi-circumference with reference to the second stage in a condition worn by the user and with the user in the upright position. 
     
     
         5 . The pressure reducing second stage ( 1 ) according to  claim 3 , wherein in said worn and upright position of the user the tongue extends substantially horizontally or parallel to a transverse plane of the user's head or parallel or coinciding with a diametric plane coinciding with a greater diameter of the mouthpiece ( 105 ) in a condition mounted on the inhalation/exhalation mouthpiece tube ( 102 ). 
     
     
         6 . The pressure reducing second stage ( 1 ) according to  claim 3 , wherein said tongue ( 200 ) axially extends from a position, where said tongue substantially overlaps an outlet port of the bypass tube ( 101 ) in the inhalation/exhalation mouthpiece tube ( 102 ), with one end thereof facing towards an inside of the pressure reducing second stage, up to an opposite end region of said inhalation/exhalation mouthpiece tube ( 102 ), facing the user and adapted to be coupled to a mouthpiece element ( 105 ). 
     
     
         7 . The pressure reducing second stage ( 1 ) according to  claim 3 , wherein the tongue has one of the following configurations:
 completely flat; or   with a curved pattern at least for a part according to at least one of the two axial and radial directions or according to both the axial and radial directions and with radii of curvature different from each other and constant or variable along an angle extension of the curved pattern.   
     
     
         8 . The pressure reducing second stage ( 1 ) according to  claim 6 , wherein said tongue ( 200 ) ends with a substantially diametric leading edge, in a region downstream of the outlet port of the bypass tube ( 101 ) in the inhalation/exhalation mouthpiece tube ( 102 ) and extends till overlapping said outlet port by an appendage ( 205 ) extending said leading edge of the tongue ( 200 ). 
     
     
         9 . The pressure reducing second stage ( 1 ) according to  claim 8 , wherein said appendage ( 205 ) has different shapes and dimensions of a base configuration. 
     
     
         10 . The pressure reducing second stage ( 1 ) according to  claim 8 , wherein said appendage ( 205 ) alternatively has one configuration selected from the group consisting of:
 a first curvature according to one axis parallel to the axis of the inhalation/exhalation mouthpiece tube ( 102 ) and with a predetermined length substantially corresponding to an axial distance of the outlet port of the bypass tube ( 101 ) in the inhalation/exhalation mouthpiece tube ( 102 ) from a rear side of the tongue ( 200 ) and an end portion with a cap-shape, or   only one radius of curvature around a single axis oriented in a diametric direction with respect to the inhalation/exhalation mouthpiece tube, or in a direction parallel to the tongue ( 200 ) and to a rear edge thereof.   
     
     
         11 . The pressure reducing second stage ( 1 ) according to  claim 8 , wherein said appendage ( 205 ) has a protrusion ( 206 ) overlapping a lower side of the tongue ( 200 ) from which said appendage extends. 
     
     
         12 . The pressure reducing second stage ( 1 ) according to  claim 3 , wherein the tongue ( 200 ) is mounted removably in the inhalation/exhalation mouthpiece tube ( 102 ) by a cooperating system coupling the tongue with an inner shell wall of said inhalation/exhalation mouthpiece tube. 
     
     
         13 . The pressure reducing second stage ( 1 ) according to  claim 3 , further comprising in combination a series of different tongues ( 200 ) that have different shapes and dimensions and that are mounted alternatively inside the inhalation/exhalation mouthpiece tube. 
     
     
         14 . The pressure reducing second stage ( 1 ) according to  claim 1 , wherein a portion of the second port ( 112 ′) provided on the shell wall of the inhalation/exhalation mouthpiece tube ( 102 ) is surrounded by a wall protruding into said inhalation/exhalation mouthpiece tube ( 102 ) and bends toward the port of the inhalation/exhalation mouthpiece tube ( 102 ) opposite to a port in connection with the case ( 106 ) to form a cap-shaped wall ( 121 ) above said second port ( 112 ′), and wherein which cap-shaped wall ( 121 ) conveys the breathing gas from the bypass tube ( 101 ) towards the user's mouth. 
     
     
         15 . The pressure reducing second stage ( 1 ) according to  claim 14 , wherein said cap-shaped wall ( 121 ) extends longitudinally for a given portion inside said inhalation/exhalation mouthpiece tube ( 102 ) to form, inside said mouthpiece tube ( 102 ), a second tube ( 121 ) extending lengthwise along the mouthpiece tube ( 102 ) and placed at the lower shell wall of the inhalation/exhalation mouthpiece tube ( 102 ), said second tube ( 121 ) conveying the breathing gas coming from the bypass tube ( 101 ) to the user's mouth. 
     
     
         16 . The pressure reducing second stage ( 1 ) according to  claim 15 , wherein said second tube ( 121 ) into the inhalation/exhalation mouthpiece tube ( 102 ) has a length ranging from 5 to 10 mm. 
     
     
         17 . The pressure reducing second stage ( 1 ) according to  claim 15 , wherein said tube ( 121 ) in the inhalation/exhalation mouthpiece tube ( 102 ) has a length equal to 7 mm. 
     
     
         18 . The pressure reducing second stage ( 1 ) according to  claim 14 , wherein a portion of the tube facing the port of the mouthpiece tube ( 102 ) opposite to the port in connection with the case ( 106 ) has an enlargement flare. 
     
     
         19 . The pressure reducing second stage ( 1 ) according to  claim 18 , wherein said enlargement flare has an angle of 10°. 
     
     
         20 . A pressure reducing second stage ( 1 ) for underwater use comprising:
 a case ( 106 ) provided with a breathing gas inlet and with a inhalation/exhalation port through which breathing gas supplied into the case is inhaled by a user and through which the user supplies exhaled gas into the case, said case ( 106 ) being further provided with a first exhaled gas exhaust outlet having a non-return valve,   the inhalation/exhalation port being connected to an inhalation/exhalation mouthpiece tube ( 102 ) through which the breathing gas, inhaled by the user, is exhaled into the case ( 106 ),   the breathing gas inlet in the case ( 106 ) being connected to a breathing gas pressure reducing device provided with a hollow cylindrical element ( 107 ), said hollow cylindrical element ( 107 ) having a breathing gas inlet port ( 117 ) communicating, through a valve, with a gas supply conduit ( 103 ), said valve being interposed between said supply conduit ( 103 ) and said inhalation/exhalation mouthpiece tube ( 102 ) for said breathing gas,   said case ( 106 ) being further provided with pressure sensitive device that controls opening and closing of said valve,   which second stage further comprises:   a bypass tube, supplying said breathing gas from the pressure reducing device directly into the inhalation/exhalation mouthpiece tube ( 102 ), upon the opening of the valve, the bypass tube ( 101 ) being connected, at one end thereof, to a first port ( 112 ) provided on a shell wall of the hollow cylindrical element ( 107 ) of the pressure reducing device, and at an opposite end to a second port ( 112 ′) provided on a shell wall of the inhalation/exhalation mouthpiece tube ( 102 ),   wherein a portion of the second port ( 112 ′) provided on the shell wall of the inhalation/exhalation mouthpiece tube ( 102 ) is surrounded by a wall protruding into said inhalation/exhalation mouthpiece tube ( 102 ) and bends toward the port of the inhalation/exhalation mouthpiece tube ( 102 ) opposite to a port in connection with the case ( 106 ) to form a cap-shaped wall ( 121 ) above said second port ( 112 ′), and wherein which cap-shaped wall ( 121 ) conveys the breathing gas from the bypass tube ( 101 ) towards the user's mouth.