I thought I may pick some collective brains. Some time after my father died I discovered by accident in a search a patent in his and Andrew Dalrymple's (of Chilton monoplane fame) name. The original link was a PDF doc with diagrams but it now appears broken. Have found another which starts with:
"
Abstract of GB573127 573,127. Helicopters. DALRYMPLE, A. W. H., and LINDSLEY, F. Dec. 3, 1943, Nos. 20265/43 and 4326/44. [Class 4] A helicopter of the type in which the sustaining rotor is positively driven by a prime mover about an upright axis transverse to the fuselage, is controlled in flight by a thrust-producing device, such as an airscrew or reaction jet, located at the tail of the machine and mounted in such a way that the line of thrust can be set at varying angles.."
The actual link is
GB Patent 573127 - Improvements in or relating to aircraft of the helicopter type
Can anyone shed some light on the subject? I knew nothing about it.
Below some pix I took of his drawings of the Chilton Olympia that I found after his death.