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Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.) Filing date Publication date Application filed by Hirobo Ltd filed Critical Hirobo Ltd Priority to US14/272,839 priority Critical patent/US9199729B1/en Assigned to HIROBO CO., LTD. Original Assignee Hirobo Ltd Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.) ( en Inventor Takakazu Uebori Shunichi Suzuki Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.) Active, expires Application number US14/272,839 Other versions US20150321754A1
#Zipster coaxial helicopter pdf#
Google Patents Coaxial counter-rotating unmanned helicopterÄownload PDF Info Publication number US9199729B1 US9199729B1 US14/272,839 US201414272839A US9199729B1 US 9199729 B1 US9199729 B1 US 9199729B1 US 201414272839 A US201414272839 A US 201414272839A US 9199729 B1 US9199729 B1 US 9199729B1 Authority US United States Prior art keywords main rudder rotor end portion mast Prior art date Legal status (The legal status is an assumption and is not a legal conclusion. Google Patents US9199729B1 - Coaxial counter-rotating unmanned helicopter US9199729B1 - Coaxial counter-rotating unmanned helicopter