GB1119409A - Improvements relating to flying helmets - Google Patents

Abstract

1,119,409. Flying helmet. M. L. AVIATION CO. Ltd. 9 Nov., 1966, No. 47500/65. Addition to 951,817. Heading A3V. A flying helmet has a visor 2 which is movable between an upper open position (Fig. 2) and a closed position (Fig. 4) and includes a mechanism for automatically locking the visor in the closed position when the wearer is subjected to a G-force equivalent to that which might be experienced by the wearer on being ejected from his aircraft by an ejection seat. The visor 2 is mounted on arms 6 which are pivoted to the helmet at 3. A tension spring 10 extends between an anchor point 12 on the helmet and the end 11 of a lever 8 pivoted to the arm 6 at 7, the lever 8 being connected to an inertia lever 9, this assembly forming a two-stage over-centre mechanism. The visor 2 is held in its open position by the spring 10 and by a spring-loaded catch 22 which engages an extension 24 of the arm 6. When the visor 2 is closed manually the spring 10 moves to the other side of the pivot 3 to hold the visor in its closed position determined by extension 28 engaging a stop 21. If the wearer is then subjected to a G-force the inertia lever 9 swings the lever 8 clockwise (Fig. 4) so that the spring moves to the other side of the pivot 7, thus biassing the lever 9 so that a projection 14 on the lever 9 engages a pin 13 to lock the visor 2 in the lower position. The lever 9 can be manually released by an extension 15. If the wearer is subjected to the G-force with the visor open, the G-force causes the visor to swing to its closed position and then locks it in its closed position as described above.