| 摘要 |
Discloses is a safety hatch cover apparatus illustrated as used on a tank of a tank-carrying vehicle such as a gasoline truck. The apparatus comprises a base member attached to the tank and having an opening adapted to be closed by a hatch cover hinged to the base member. The hatch cover carries a latch bar rotatable about an axis perpendicular to the base member and adapted to engage keeper members fixed to the base member adjacent the hatch opening. The latch bar carries a cam which turns with the longitudinal axis of the latch bar and engages biasing means carried by the cover. The biasing means, cam, latch bar and keeper members cooperate to close the cover yet permit the cover to lift in case of excess gas pressure in the tank. The apparatus also includes safety means adapted to engage the latch bar to restrain it from moving from its position in which it engages the keeper members, whether or not the cam is turned to cause the latch bar to be in locked position.
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