Abstract: Apparatus for venting, which is used with a door such as a sectional garage door, which permits the top door section to pivot inwardly a controlled distance, by a mechanical opener or an electrically controlled solenoid opener, which permits venting of a space.

Abstract: A self-calibrating measuring tool. The tool includes a housing having a base and a recess terminated by a precisely located flange with respect to the base. A linear movable member is mounted within the housing with a measurement arm attached to it. A transducer is connected to the member for providing a measurement indication.

Abstract: A tool for aligning engine cylinder heads on engine blocks prior to final assembly of the head to the block, which tool is inserted in bolt holes in the head and block, permits of final gasket placement and inspection, the tool including a central body, a plurality of steel balls carried in an inclined passageway, a nose piece carried in the body engaged with one of said balls to force the other ball partially out of said inclined passageway and a handle for rotating the nose piece, to permit the balls to retract into the passageway and the head to pass over the tools and be guided down onto the block.