摘要 |
<p>A second pressure reducing stage for scuba regulators, which has a breathing gas mixture supply chamber (1), having a gas mixture inlet (2), which has, on the side turned toward the chamber (1), a valve orifice (3) cooperating with a poppet seat (4) which is placed at an end of a poppet (5), sliding axially inside a tubular element (6) to move the seat (4) away and closer to said orifice (3), hence to open and close the inlet (2), the poppet (5) being held in the closed position, in the non inhalation condition, by a compression spring (7) whereas, during inhalation, said poppet (5) is driven toward opening the inlet (2) by the negative pressure of inhalation and/or by the pressure of the gas supplied into the second stage, the poppet (5) having a body of a smaller radial size than the opening size of the tubular guide element (6) and ridges or tabs (12) for centering and guiding it, which slideably cooperate with the inner surface of the tubular element (6). The invention provides means for preventing the poppet (5) from rotating relative to the tubular element (6), by providing that at least one of the tabs (12) or each of at least two tabs (12, 20), or all the tabs, which have different angular orientations, slideably engage in corresponding axial guide means formed on the inner surface of the tubular guide element (6), such as a groove (14, 21), or an axial longitudinal rail (18) formed on the inner wall of the tubular element (6).</p> |