Hallsten Corporation

Ronald Kuehne

Jeffrey A Hallsten

Roland C Wright

Gary Powell

A tank cover, especially a cover on a sewage treatment tank, is provided with an access opening with a liftable hatch cover. Along with the hatch cover is a safety barrier or grate, either connected directly to the hatch cover or to structure surrounding the hatch opening. When the hatch is opened the barrier is deployed to prevent a worker from accidentally falling through the opening. In one form the barrier is pivotally attached to the bottom side of the hatch cover, and can be swung out as the hatch is opened to form an 'A' shaped or roof shaped barrier, with the hatch cover and the barrier both inclined and essentially forming a roof over the opening. Braces or struts hold these components in the erected position and provide barriers from the sides. For entry of a person through the opening, the barrier or grate can be retained against the bottom of the hatch cover as the cover is swung fully open, through 180&#xb0;. In another form the barrier is secured to tank cover structure just below the hatch cover and can be left in place as a horizontal barrier when the cover is fully opened. For access into the tank the barrier/grate can be swung back in the same direction as the access cover and stacked on the opened access cover.

Tank cover access hatch with safety barrier

A modular biofiltration support system for a bed of organic filter medium, formed of a multiplicity of rectangular bed platform modules or floor tiles, provides for bridging across an air/gas supply trench which can be up to 36 inches or even 48 inches wide. The bridging sections, formed of a mix of recycled plastic materials in a high-pressure molding operation, interconnect with edges of the floor tile assemblies on each side of the trench, and also engage with one another at sides. Each module is a high strength beam.

Growing community of inventors

Lincoln, CA, United States of America

Ronald Kuehne