Resistance type oxygen sensor

An oxygen sensor particularly adapted for detecting the oxygen concentration in the exhaust gas of an internal combustion engine exhaust system comprising:

• a first generally cylindrical electrical insulator having an axial bore extending therethrough with one end of said bore being counterbored for a substantial distance, said first insulator having a radially enlarged outer portion spaced from the second end thereof;
• an annular connector shell which fits over and engages said radially enlarged portion of said first insulator and is adapted to be secured in a wall of the exhaust system with the second end of said first insulator disposed in the exhaust stream;
• a second electrical insulator of substantially uniform circular cross-section disposed in said bore in the first insulator and with a first end thereof adjacent the counterbore, said second insulator having at least two longitudinal bores therethrough;
• a means for retaining said second electrical insulator in said bore in the first insulator;
• a detector element having at least two electrical leads, said element being disposed adjacent the second end of the first insulator with the electrical leads thereof extending through the longitudinal bores in said second insulator into the counterbore in the first insulator;
• at least two terminals disposed longitudinally in the counterbore in the first insulator with an outer end extending axially beyond the first end of the first insulator, said electrical leads each being electrically connected to the inner end of one of said terminals;
• and
• electrically nonconductive means for supporting the terminals in place in the counterbore.