A sheet blank for forming a collapsible field director structure comprises a sheet of nonconductive material having at least three panels thereon, one of the panels being a master panel and the other two panels being slave panels. Each panel is substantially rectangular in shape and has elongated upper...http://www.google.es/patents/US7985462?utm_source=gb-gplus-sharePatente US7985462 - Multi-panel blank with parallel panel axes for a collapsible field director structure
Multi-panel blank with parallel panel axes for a collapsible field director ...
