Guide fin with extension for rocket - has sliding fin in cavity pushed out by spring force after launching

摘要

The guide fins of rocket are extended from their retracted positions. This rocket is launched from barrel whose bore size matches rock outside diameter. The fins have sufficient stiffness for large span and low air resistance. Each fin (7) is hollow and it holds an extension (8) which is extended when the fin is opened. The extension moves until it meets a stop. The extending part of the fin is moved by the spring (19). The hollow fin part are made from sheet metal and fin leading and trailing edges are stiffened by solid reinforcements. The fins can be extended by means of explosive gas force as alternative to springs for pushing out extension fin.