First Stage Pressure Reducing Valve Having A Tubular Plug, Particularly For Regulators Of Scuba Breathing Apparatus

Abstract

Embodiments of the invention relate to a first stage pressure reducing valve having a tubular plug, particularly for regulators of scuba breathing apparatus. According to embodiments of the invention, at least a portion of the outer surface of the valve has fins for heat exchange with the outside environment, designed to prevent or reduce the formation of ice caused by the temperature drop generated by gas expansion inside the valve.

1 . A first stage pressure reducing valve for regulators of underwater scuba breathing apparatus comprising:
 a valve member;   a valve body defining a cavity in which the valve member is slidably received, the valve member separating the cavity into a high pressure chamber and an outlet chamber, the valve member slidable between an open position wherein the high pressure chamber fluidly communicates with the outlet chamber and a closed position wherein the high pressure chamber is prevented from fluidly communicating with the outlet chamber, the valve member and valve body further defining a pressure compensation chamber therebetween, the pressure compensation cavity including a hole fluidly communicating the pressure compensation cavity with the ambient water surrounding the valve;   a biasing member biasing the valve member towards the outlet chamber; and   a plurality of fins positioned proximate the hole preventing ice from forming and obstructing the hole.   
     
     
         2 . The first stage pressure reducing valve of  claim 1 , wherein the outlet chamber is a low pressure area of the valve body and the heat transfer fins are provided in the low pressure area of the valve body. 
     
     
         3 . The first stage pressure reducing valve of  claim 1 , wherein the heat transfer fins are integrally formed with the valve body. 
     
     
         4 . The first stage pressure reducing valve of  claim 1 , wherein the heat transfer fins are a separate component piece coupled to the valve body. 
     
     
         5 . The first stage pressure reducing valve of  claim 1 , wherein the valve body includes a partition wall separating the high pressure chamber from the compensation chamber and the valve member is in the form of a tubular plug slidably passing through the partition wall having one end in the high pressure chamber and the other end being a piston-like head in the compensation chamber, the piston-like head separating the compensation chamber from the outlet chamber with the outlet chamber on the side of the piston-like head opposite the partition wall. 
     
     
         6 . The first stage pressure reducing valve of  claim 5 , wherein the biasing member is positioned within the pressure compensation cavity. 
     
     
         7 . The first stage pressure reducing valve of  claim 1 , wherein the plurality of fins includes at least one annular fin disposed over the hole at a certain distance therefrom, which leaves a communication passage from the compensation chamber to the ambient surroundings whose axis is oriented transverse to the hole axis. 
     
     
         8 . The first stage pressure reducing valve of  claim 5 , further including a connection terminal coupled to the valve body communicating with the outlet chamber, the coupling terminal providing a connector for connecting the valve body to an air outlet pipe and wherein the plurality of fins are formed as a separate finned element secured to the valve body by the coupling terminal. 
     
     
         9 . The first stage pressure reducing valve of  claim 8 , wherein a wall forming an outer surface of the valve body and forming the outlet chamber and the compensation chamber tapers in annular steps that get larger in a direction extending away from the connection terminal and toward the compensation chamber and the element has a corresponding inside shape which tapers in corresponding steps increasing the contact surface between the finned element and the outer surface of the wall. 
     
     
         10 . The first stage pressure reducing valve of  claim 9 , wherein the finned element is clamped between radially outward projecting portions of the steps of the wall and the connection terminal. 
     
     
         11 . The first stage pressure reducing valve of  claim 1 , wherein the pressure compensation cavity includes a plurality of holes fluidly communicating the pressure compensation cavity with the ambient surroundings of the valve and the a plurality of fins are positioned proximate the holes preventing ice from obstructing the hole. 
     
     
         12 . The first stage pressure reducing valve of  claim 1 , wherein one of the plurality of fins axially ends at an edge of the hole. 
     
     
         13 . The first stage pressure reducing valve of  claim 1 , wherein the plurality of fins are annular fins that entirely surround the outlet chamber. 
     
     
         14 . A first stage pressure reducing valve for regulators of underwater scuba breathing apparatus comprising:
 a valve member;   a valve body defining a cavity in which the valve member is slidably received, the valve member separating the cavity into a high pressure chamber and an outlet chamber a high pressure chamber, the valve member slidable between an open position wherein the high pressure chamber fluidly communicates with the outlet chamber and a closed position wherein the high pressure chamber is prevented from fluidly communicating with the outlet chamber, the valve member and valve body further defining a pressure compensation cavity therebetween, the pressure compensation cavity including a hole fluidly communicating the pressure compensation cavity with the ambient surroundings of the valve;   a biasing member biasing the valve member towards the outlet chamber; and   means for retarding ice formation on an outer surface of the valve body to prevent ice from obstructing the hole.   
     
     
         15 . The first stage pressure reducing valve of  claim 14 , wherein the retarding means are integrally formed in a boundary wall of the valve body. 
     
     
         16 . The first stage pressure reducing valve of  claim 14 , wherein the retarding means are formed as a separate retarding element that is independently couplable to a boundary wall of the valve body. 
     
     
         17 . The first stage pressure reducing valve of  claim 14 , wherein the retarding means only partly angularly surrounds the outlet chamber. 
     
     
         18 . A method of reducing ice formation of ambient water surrounding a first stage pressure regulator to prevent obstruction of fluid communication between the ambient surroundings of first stage pressure reducing valve and a pressure compensation cavity, the pressure compensation cavity being separated from an outlet chamber of the valve body by a valve member that is biased towards the outlet chamber by a biasing means, the biasing of the valve member towards the outlet chamber is compensated by changes in pressure of the ambient acting on the valve member, further wherein a temperature gradient across a boundary wall separating the outlet chamber and the ambient is such that the outlet chamber is at a lower temperature than the ambient, the method comprising the step of:
 reducing the amount of heat transferred from localized portions of the ambient water by drawing heat from a larger amount of ambient water.   
     
     
         19 . The method of  claim 18 , further including the step of mounting a finned element to the boundary wall of the valve body.