Tilt sensor and top cover plate thereof

摘要

A tilt sensor includes a sealed container formed of a container body, a top cover plate adapted to close the container body and provided on one end surface thereof with a recess having a concave surface whose depth gradually increases from a peripheral edge toward a center thereof. The tilt sensor further includes a liquid enclosure containing an air bubble, that is enclosed in the container body. To coincide the center of the configuration of the top cover plate with a line normal at a deepest portion of the concave surface at a grinding operation after molding the top cover plate, an indicia is provided on the line normal to the concave surface at the deepest point of the concave surface.