Blade pitch control in rotatable devices for vehicles

Abstract From the Canadian patent

A rotatable bladed device for vehicles such as, especially a helicopter rotor which has its blade pitch, controlled by a setup which includes a swash plate setup controlled by a set of hydraulic actuators and the particular swash plate setup position and attitude in turn controls the blade pitch by a plurality of rods pivoted together at one end at one particular point movable longitudinally of the rotor axis, one of which rods has its other end pivoted at a point on the pitch arm by which it controls pitch and another of which rods is also pivoted at a point fixed by the rotational position at any particular time of the rotor hub.