Abstract: A grating fastener which can be used to connect grating to structural members, grating sheets to other grating sheets, or to mount a projection means above the grating for connection of other structural or mechanical devices. The grating fastener in one embodiment includes a jaw assembly which has teeth that provide extra strength and holding power for the grating fastener. The top cover or recess clip mounts on top of the grating and includes a square recess area which provides additional strength and durability. The grating fastener can be installed from above the grating by one person with no power tools required and without any holes required to be formed into the structure. The grating fastener is easily retrievable and thus can be reused as many times as desired.

Abstract: A two-stroke cycle engine is provided with valveless exhaust and inlet ports in a cylinder wall. A piston is mounted for reciprocal movement in the cylinder. A precombustion chamber is formed in the piston, which communicates with the combustion chamber above the piston by a relatively large aperture adapted to receive the end of a spark plug. When the piston is at the bottom of its stroke, pressurized fresh air is supplied through the inlet ports for purposes of scavenging the combustion chamber and filling it with fresh air. There is also provided means for forcing a charge of rich fuel-air mixture into the precombustion chamber. The aperture providing communication between the precombustion chamber and the combustion chamber is sufficiently large that a desired amount of fuel can be ejected into the combustion chamber. During the compression stroke of the piston, the fuel-air mixtures in the precombustion chamber and in the combustion chamber are compressed.