Gas sensor, particularly oxygen sensor exposed to combustion exhaust gases

Claim 1

Gas sensor, particularly to determine oxygen content in combustion exhaust gases, especially from an internal combustion engine having an elongated tubular housing (11, 17) defining a sensing end portion and a connecting end portion of the sensor; a tubular solid electrolyte sensing element (26), closed at the sensing end portion located at the sensing end portion of the housing and secured therein, and having layer electrodes (28, 30) thereon extending over, respectively, an outer and an inner surface thereof; An electrical heating element (36) located within the tubular solid electrolyte element having a layer heater means (37) terminating in two heater connecting zones (40, 40'), said heater element (36) comprising an elongated rod portion and a flange end portion, said layer heater means extending on the rod portion, said flange end portion having a diameter larger than the diameter of the elongated rod portion, being located at the end remote from the closed end of the tubular electrolyte, and having an end face (39) facing the connecting end portion of the sensor, said heater connecting zones (40, 40') being located on said end face (39), a plurality of electrically conductive tracks (38, 48) formed on said heater element, a first (48) of said tracks being in electrical contact with that one (30) of the layer electrodes of the sensing element at the inner surface of the sensing element and extending to a connecting zone (49) on the end face (39) of the heater element, and a second (38) and a third (38) of said tracks connecting said heater means with the heater connecting zones (40, 40') on the end face (39) of the heater element, and electrical connection means (58) extending within the housing and in electrical contact with the respective electrically conductive connection portions and leading to the terminal end of the connecting portion of the sensor.