Abstract: A roller assembly for attachment to a lawnmower. The roller assembly generally includes a tow arm having first and second links. The first link is configured to be supported at least indirectly on the lawnmower frame. The second link is connected to a shaft mounted with one or more rollers. A spring is disposed between the first and second links and configured to bias the second link downwardly relative to the first link, thereby biasing the rollers against a ground surface. The roller assembly further includes a quick connect assembly for rapid attachment and detachment of the roller assembly to the lawnmower. The roller assembly yet further includes a latch assembly configured to hold the second link and shaft of rollers in a raised position relative to the ground surface.

Abstract: An roller assembly for attachment to a lawnmower. The roller assembly generally includes a tow arm having first and second links. The first link is configured to be supported at least indirectly on the lawnmower frame. The second link is connected to a shaft mounted with one or more rollers. A spring is disposed between the first and second links and configured to bias the second link downwardly relative to the first link, thereby biasing the rollers against a ground surface. The roller assembly further includes a quick connect assembly for rapid attachment and detachment of the roller assembly to the lawnmower. The roller assembly yet further includes latch assembly configured to hold the second link and shaft of rollers in a raised position relative to the ground surface.

Abstract: A stowable and self-deployable array antenna includes flat, rectangular antenna panels hinged side-by-side so that when deployed they are coplanar, and they fold like an accordion for stowing. The deployed array antenna is stiffened by lateral stiffening panels hingedly attached to every other hinge between antenna panels, and to the unhinged ends of the antenna panels. Foldable longitudinal stiffening panels hinged between adjacent lateral stiffening panels. Each hinged connection includes a pair of thin spring elements, corresponding to a portion of a cylinder. The two spring elements of each hinge are spaced apart with their concave sides facing, and with the axes of the defining cylinder parallel. The hinge pivots, when the spring elements buckle, about a line orthogonal to a line extending between the cylinder axes. The hinges are used as the structural elements of self-deployable masts. The mast may have a polygonal cross-section.

Abstract: A stowable and self-deployable array antenna includes flat, rectangular antenna panels hinged side-by-side so that when deployed they are coplanar, and they fold like an accordion for stowing. The deployed array antenna is stiffened by lateral stiffening panels hingedly attached to every other hinge between antenna panels, and to the unhinged ends of the antenna panels. Foldable longitudinal stiffening panels are hinged between adjacent lateral stiffening panels. Each hinged connection includes a pair of thin spring elements, corresponding to a portion of a cylinder. The two spring elements of each hinge are spaced apart with their concave sides facing, and with the axes of the defining cylinder parallel. The hinge pivots, when the spring elements buckle, about a line orthogonal to a line extending between the cylinder axes. The hinges are used as the structural elements of self-deployable masts. The mast may have a polygonal cross-section.