First stage pressure regulator with threshold actuation

A first stage pressure reducer for two-stage breathing groups, comprising:

• a first chamber adapted to receive a high pressure breathable gas, the first chamber being connected to or configured to be connected via an inlet to a source of the high pressure breathable gas;
• a second chamber adapted to receive the breathable gas at an intermediate pressure, the second chamber having an outlet for the breathable gas at the intermediate pressure and being configured to be connected to a user of an intermediate pressure breathable gas;
• and
• a pressure reducing valve connecting the first chamber to the second chamber and comprising a valve seat with a communication opening between the first and the second chamber and a shutter cooperating with the valve seat and movable from a closed position of a passage opening to an open position of the passage opening and vice versa,
• wherein the shutter is dynamically connected to a sensing member of a pressure of an external environment outside the first and the second chamber, the sensing member comprising a transmission mechanism configured to transmit a mechanical load applied on the sensing member by the pressure of the external environment outside the shutter, and
• wherein the transmission mechanism is provided with a suspension/restoration member of a transmission kinematic chain acting based on the mechanical load applied thereon by the pressure of the external environment, the suspension/restoration member causing a suspension of the transmission kinematic chain when the mechanical load is below a predetermined threshold value and restoring the transmission kinematic chain when the mechanical load is equal to or exceeds the predetermined threshold value.