Sealed head construction for liquid level transducers

A mounting head assembly (14) for connection to a cryogenic tank (12) having a tank wall (15) and an opening (17) formed therein, and being adapted for sealing the tank opening (17) to thereby maintain pressure within the tank (12), the mounting head assembly comprising:

• a lower mounting member (40) having a first body (50) with a first upper connecting portion (60) and a first central bore (68) extending therethrough, the lower mounting member being adapted for connection to a sensor probe (16);
• a tank mounting member (42) having a second body (70) with a lower connecting portion (72), a second central bore (74) and a third central bore (85) formed therein and a fixed intermediate wall section (87) formed in the second body and located between the second and third central bores;
• the fixed intermediate wall section (87) being integral with the second body (70) and extending transverse to a central axis of the second and third central bores;
• the first upper connecting portion (60) being received and retained within the second central bore (74) and being operably associated with an upper surface (144 or 150) located adjacent to the fixed intermediate wall section (87);
• a corrugated feature (152, 154, 167, 169) associated with at least one of the fixed intermediate wall section (87) and the upper surface (144 or 150);
• and
• an inner seal (112, 147) constructed of resilient material and configured for location in the second central bore (74) between the fixed intermediate wall section (87) and the upper surface (144 or 150), the inner seal being pressed into the corrugated feature by moving the first upper connecting portion (60) toward the fixed intermediate wall section (87) to thereby interlock the inner seal and the corrugated feature while increasing a surface area therebetween and seal the mounting head assembly against leakage.

A transducer (10) for determining the level of liquid within a pressurized tank (12), the transducer comprising:

• a mounting head assembly (14) adapted for connection to the tank (12);
• and
• an elongate sensing probe assembly (16) adapted to extend into the tank from the mounting head assembly (14);
• the mounting head assembly comprising a lower mounting member (40) with a first central bore (68) for receiving at least a portion of the sensing probe assembly (16), and a tank mounting member (42) with a lower connection portion (72) comprising a second central bore (74), a third central bore (85) coaxial with the second central bore and separated therefrom by a fixed transverse wall (87) located between the second central bore and the third central bore;
• the second central bore being sized to receive at least a portion of the sensing probe assembly;
• the lower mounting member (40) having an upper connecting section (60) located within the second central bore (74) with an upper end of the upper connecting section being operably associated with an upper surface (144 or 150) located adjacent to the fixed transverse wall;
• and
• an inner seal (147) positioned between the fixed transverse wall (87) and the upper surface (144 or 150) operably associated with the upper connecting section (60), at least one of the transverse wall and the upper surface (144 or 150) having a first corrugated shape that receives the inner seal to thereby form a labyrinth-type seal for sealing the mounting head assembly against leakage between the mounting head and the lower mounting member.