Abstract: In a fuel cell assembly, a passive gas spring is disposed between the stack and the supporting structure for maintaining compressive force on the stack and manifold seal. As variation in temperature of the assembly and structure causes dimensional changes therein, the pressure within the gas spring also changes accordingly. The gas spring is provided with inlet and outlet check valves, the outlet check valve opening to expel air when internal spring pressure reaches a predetermined upper pressure limit, and the inlet check valve opening to admit air when the internal spring pressure falls below a predetermined lower pressure limit in a currently preferred embodiment, the outlet check valve allows exit of gas from the gas spring at pressures exceeding 5 psig, to prevent rupture of the gas spring, and the inlet check valve allows entrance of gas into the gas spring as the spring cools following use.

Abstract: A non-contact fuel vaporizer adds heat to the injected fuel by combining the fuel with heated air in a vaporization chamber downstream of air supply inlets. The fuel is metered axially through a conventional fuel injector. The heated air is metered through an air director plate that introduces the air in a helical trajectory concentrically around the injector spray. When the hot swirling air comes in contact with the atomized fuel, substantially all of the fuel is vaporized before coming into contact with a wall of the vaporization chamber.

Abstract: A first pattern, which has on its outer periphery a series of intersecting surfaces, is used in a conventional edger unit to control the rough grinding of a corresponding series of intersecting surfaces on the edge of a revolving lens blank. A second pattern is then inserted in the edger to control a first bevel grinding operation during which a bevel grinding wheel is caused intermittently to engage the revolving lens blank to form thereon a first plurality of angularly spaced, beveled surfaces at least one of which registers with one of the intersecting surfaces on the blank. A third pattern is then inserted in the edger to control a second bevel grinding operation during which the bevel grinding wheel forms a second plurality of beveled surfaces on the lens blank in the spaces between the first plurality, and in registry with the remainder of said flat surfaces on the blank.