Abstract: A control rod (10) is grounded to a structure (14) at an opening (16) through which it moves longitudinally by sliding contact with a conductive wiper (18, 29, 40, or 48). The wiper is mounted to the structure (14) by conductive arms (26) and brackets (28), or by a joint (36), or by a housing (44), or by a boot (50) so that the wiper can track transverse motion of the rod (10).

Abstract: A flight control system for a helicopter tail rotor having a semicircular quadrant 18 with bell cranks 36, 40 mounted on either end of the quadrant and flexible control cables 20, 22 connected to each bell crank. The bell cranks are spring loaded in opposition to cable tension, and a fixed abutment 72 provides a reaction against the bell crank springs in the event of a cable severance. The quadrant works against the spring loading of one bell crank in the event of breakage of the opposite control cable and is centered by the spring loading of both bell cranks if both cables are broken.

Abstract: The guard retains the cable on a pulley of a cable control system that indes another pulley mounted on a pivotable radius arm for swingable movement relative to it. Usually, the swingable pulley is linked to a third pulley mounted on a hinged structural member which itself swings with the radius arm to and from `closed` or `open` positions. When the arc is wide, i.e. around 180.degree., conventionally mounted guards engage and bind the swinging cable. The present guard is an elongate member pivotally mounted on the radius arm. In the `closed` position, a retaining flange formed on the guard moves for cable retaining purposes into close proximity with the fixed pulley and the proximity or clearance can be adjustably fixed and locked by an eccentric stop. During the `opening` swing, the cable engages the guard which then pivots sufficiently to prevent the undesired binding. The pivotal range of the guard is restricted by a pin and slot arrangement.

Abstract: A pivotal joint in which a first member having a wheel-shaped end is pivotally connected to a second member having a forked end enveloping the wheel-shaped end and including a primary pivot bolt arrangement extending through the first and second members at the center of the wheel-shaped end to pivotally join the parts, as the primary pivotal connection therebetween and wherein the forked end of the second member presents a circumferential array of three friction surfaces which will cooperate with the periphery of the wheel-shaped end of the first member to pivotally join the two parts as the secondary pivotal connection therebetween if the primary pivot connection fails.