Abstract: The dual area brake actuation piston mechanism (10, 110) comprises a piston housing (12, 112) having therein a first bore (30, 130) disposed coaxially about a separate second bore (40, 140). A first piston (50, 150) is disposed within the first bore (30, 130) and extends from the first bore (30, (130) to a piston end (70, 170). A second piston (60, 160) is disposed within the second bore (40, 140) and extends to engage the piston end (70, 170). The bores (30, 40; 130, 140) have first and second bore openings (32, 42; 132, 142) for receiving pressurized fluid which displaces the respective pistons (50, 60; 150, 160). The second bore opening (42, 142) includes a valving mechanism (80, 180) to either restrict or prevent lower fluid pressures from actuating the second piston (60, 160).

Abstract: The frictional properties test mechanism (10) comprises a shaft dynamometer (12) connected with a wheel element (14) that is coupled with a braking mechanism (16) for the wheel element (14). The braking mechanism comprises a single rotor (25)/double stator (27) disc brake whose torque tube (29) is attached to a piston housing (40) and torque load cell (54). The piston housing (40), torque armature end plate (41), and torque load cell (54) are mounted by way of bearings (95) within a stationary framework (100), and connected with an oscillatory motion mechanism (18). Located adjacent the stationary framework (100) and connected by arms (24) to the end plate (41) and torque load cell (54) is a pair of spring mechanisms (20) and a pair of hydraulic cylinders (22), which are part of the oscillatory motion mechanism (18). A control and display console (121) operates the dynamometer (12) in order to effect rotary motion of the wheel element (14) and operation of the braking mechanism (16).

Abstract: The ablative bushing (40, 140, 240) is disposed between a torque tube pedestal (18) and an axle (30) of an aircraft. The ablative bushing (40, 140) encircles an axle bushing (26) located around the axle (30), so as to be disposed between the torque tube pedestal (18) and axle bushing (26). The ablative bushing (240) may also be located between a torque tube pedestal flange (114) and an axle flange (35). The ablative bushing (40, 140, 240) ablates at a predetermined temperature in order to introduce an air gap between the torque tube pedestal (18) and axle (30) to prevent excessive heat flow to the axle (30) during a rejected take-off stop.

Abstract: The brake piston return mechanism (10) comprises a housing (22) which includes housing part (50) that forms with the housing a chamber (59) and an axially extending groove (55). Disposed within the axially extending groove (55) and forming a movable portion (58) of the chamber (59) is an annular actuation piston (70). The actuation piston (70) includes a pair of seals (74) to prevent leakage. Within the housing part (50) is a bore (40) enclosing brake tube (80) that includes an interior radially extending flange (84) and an exterior radially extending flange (82). The exterior radially extending flange (82) is engaged by the actuation piston (70). Located within the brake tube (80) is an adjuster mechanism (90). After the brake tube (80) has been displaced by the actuation piston (70) and braking has ceased, the brake tube (80) is returned to a running clearance (A) by way of the adjuster mechanism (90 ).

Abstract: Carbon brake discs (14, 16) of an aircraft brake (10) include in opposing radial surfaces thereof circumferentially extending annular grooves (44, 46). Each annular groove (44, 46) may be disposed oppositely from an annular groove (44, 46) in the other radial surface of the respective disc (14, 16). Each annular groove (44, 46) extends radially from a respective adjacent axial edge (34, 36) of an adjacent disc (14, 16) and toward a peripheral area of the disc (14, 16) which is connected operatively with either a non-rotating axle (11) or a wheel supported rotatably on the axle (11). The annular grooves (44, 46) alter the contact pressure distribution between the discs (14, 16) and eliminate a portion of the disc (14, 16) wear surface which does not have continual contact with the mating wear surface of the adjacent disc (14, 16) and thereby minimize unstable rotor cycloidal motion.