Abstract: A rudder control linkage having thermal compensation features employs a stationary thermal compensation rod, a lever with a fixed pivot, a reversing link with a movable pivot, a summing link, pilot and yaw damper input rods, and output rods. In an airplane having a fin and a rudder, the linkage is utilized to cancel undesired yaw inputs to the rudder caused by fin bending and differential thermal expansion which, if not corrected, would deleteriously affect airplane trim.

Abstract: A mechanism for reducing backlash in a spline connection between cooperably splined male and female members is disclosed. One of the members, either male or female, is formed in two coaxially alignable splined segments. The splined segments have end surfaces that are shaped to engage in sliding relationship so as to cause the two segments to undergo relative rotation when the segments are subjected to a relative axial load. The mechanism includes a connecting device for subjecting the two segments to such a relative axial load. In operation, the two splined segments are first oriented with their splines in alignment and are engaged as a unit with the other splined member. The connecting device is then applied to subject the two segments to a relative axial load so as to cause the segments to rotate out of alignment with one another and thereby securely engage the splines of the segmented member with the splines of the other member.

Abstract: A bidirectional mechanical load limiter for a push-pull control linkage includes a tubular crushable core that crushes in response to a predetermined tensile or compressive load to thereby limit the load in the linkage. The load limiter includes a tubular casing and a piston arranged in a telescoping configuration. The tubular crushable core, together with a pair of slide elements positioned adjacent the opposite ends of the core, is located within the casing by stop elements affixed to the inside of the casing. The piston passes through the bore of the tubular core and the slide elements and is retained in place by impeller elements affixed to the piston adjacent and abutting the slide elements. In normal operation, the load limiter operates as a rigid link in the linkage, with tensile and compressive loads being transmitted between the piston and casing through the crushable core. Under an excessive tensile load the piston and casing undergo relative extension as the core yields under the load.

Abstract: A ratio changing mechanism is provided for combining two mechanical input signals to produce an output signal. The mechanism includes a first crank mounted on a pivoted link with an input member mounted on the first crank. The mechanical inputs are applied to the input member which moves the crank in such a manner that an output signal is transmitted from one arm of the crank. Movement of the first crank is modified by connection of the other crank arm to a second crank which is adjustable in position to change the ratio of the output to the combined input signals.