GB751828A - Toy helicopter - Google Patents

Abstract

751,828. Toy helicopters. KRAUTKRAMER, A., and KRAUTKRAMER [nee BERG], L., [trading as BERG KOMM.-GES., J.]. July 28, 1954 [Nov. 30, 1953], No. 22055/54. Class 4. A toy helicopter comprises a fuselage 1 supporting an upright rotatable shaft 3 to which a driving dog 4 and a flanged collar 5 are secured. A further collar 8, formed with a flange 9, and a removable screwed cap 11, is secured to the shaft 3 above the collar 5 and spaced therefrom by a gap which accommodates wires 7 constituting the spars of the blades. The inner end of each wire is bent upwardly at 13 to engage within a hole 14 in the collar 8 and the wire then extends along the leading edge of each blade, round the tip and back along the trailing edge to be bent forwardly at 19 and twisted round the root leading edge portion into an upwardly extending arm 15 terminating in a bend 16. Each arm 15 engages a slot 10 cut in the flange 9 and the inclination of the slot is such that acceleration of the rotor causes the blades to undergo lagging movements about the pivots 13 to cause the arms 15 to move in the slots 10 in a direction to increase the pitch of the rotor blades, which return to a normal negative-pitch setting when the rotor speed falls. To facilitate storage the blades may be folded one above another over the fuselage by springing the arms 15 out of the slots 10.