Trim execution device

In a control system, primary control means for controlling a controlled element along a range of movement via a mechanical linkage and in response to a primary signal, and trim linkage means for trimming the position of the controlled element in response to a secondary signal with the degree of trim effected by a given secondary signal input being proportional to the degree of advance of said controlled element along said range of movement, the improvement wherein the trim linkage means comprises a fulcrumed lever movable around a central fulcrum through a range of swinging movement of the lever, means responsive to said secondary signal for moving said fulcrum back and forth from a neutral point along a fulcrum path which is lengthwise of the lever when the lever is at the midpoint of said swinging movement, fulcrum-engaging slideway means on the lever extending in skewed relation to the length of the lever such that at said beginning of said range of swinging movement said fulcrum path and slideway means are parallel but become increasingly skewed as said swinging movement advances through said range, whereby the greater said advance of swinging movement of said lever, the greater the lagging or leading trimming effect, on said advance, of departure of said fulcrum back or forth from said neutral point, and input and output linkages connected to respective ends of said lever.