Patent ID: 7584647
Filing Date: 2009-09-08
Classification: G01N

Abstract:
1. A gas sensor having a length with a top end and a base end opposite the top end comprising: a sensor element sensitive to a gas to produce a signal as a function of concentration of the gas; a housing in which said sensor element is retained, said housing having a top end and a base end opposite the top end; an elastic block having holes through which leads pass to connect electrically with said sensor element, said elastic block being made up of a top portion closer to the top end of the gas sensor, a base portion closer to the base end of the gas sensor, and a neck formed between the top portion and the base portion, the base portion having a first shoulder surface, the top portion having a second shoulder surface facing the first shoulder surface in a lengthwise direction of the gas sensor; an air flow path extending within the top portion of said elastic block, said air flow path having an air inlet and an air outlet, the air inlet opening on an outer surface of the neck of said elastic block, the air outlet opening on a surface of the top portion of said elastic block exposed to an air chamber leading to said sensor element; an annular ventilation filter fitted on the neck of said elastic block in communication with the air inlet of said air flow path to permit air to enter said air flow path from outside said elastic block through said ventilation filter, said ventilation being nipped between the first and second shoulder surfaces of said elastic block; an air cover joined to said housing to extend away from the base end of the gas sensor to define therein the air chamber to which the air outlet of said air flow path is exposed, said air cover being crimped to provide a lateral elastic nip to the base portion of said elastic block in a direction perpendicular to the lengthwise direction of the gas sensor and also crimped to provide a longitudinal elastic nip to said elastic block in the lengthwise direction of the gas sensor; and an air inlet hole formed in said air cover through which the air is admitted to said ventilation filters, wherein the top portion and the base portion of said elastic block are made of discrete parts, the top portion and the base portion being arranged to provide a longitudinal elastic nip to said ventilation filter in the lengthwise direction of the gas sensor.