Indicator system for torque limiter

A torque limiter for an aircraft flight control surface actuator, the torque limiter comprising:

• an indicator system comprising:
• a first component extending around an axis (A) and comprising one or more radially extending cam surfaces;
• a second component in combination with a third component, wherein the third component is fixed against rotation relative to the second component, but is axially movable relative to the second component;
• and
• an indicator member configured to move upon axial movement of the third component away from the second component when an applied torque to one of the first component or the second component exceeds a predetermined or specified amount,
• wherein the third component comprises one or more notches, each receiving one of the radially extending cam surfaces, and upon relative rotation between the first component and the combination of the second component and the third component, a surface of each of the notches is configured to ride up a corresponding cam surface of the first component, such that the third component moves axially away from the first component, thereby causing the third component to move axially away from the second component, and
• wherein the indicator member is a lever arm pivotably connected to a rotationally fixed housing portion of the torque limiter and configured to move out of a first cavity in the housing portion of the torque limiter upon axial movement of the third component away from the first and second components, so as to provide a visual indication that the torque limiter has tripped upon inspecting the torque limiter.

A method of indicating that a torque limiter for an aircraft flight control surface actuator has tripped, the method comprising:

• transferring torque between a first shaft and a second shaft;
• rotating a first component relative to a second component when an applied torque to one of the first shaft or the second shaft exceeds a predetermined or specified amount, the first component extending around an axis (A) and comprising one or more radially extending cam surfaces;
• axially moving a third component upon rotation of the first component relative to the second component, the third component being fixed against rotation relative to the second component;
• and
• moving an indicator member upon axial movement of the third component away from the second component;
• wherein the third component comprises one or more notches, each receiving one of the radially extending cam surfaces, and upon relative rotation between the first component and the combination of the second component and the third component, a surface of each of the notches is configured to ride up a corresponding cam surface of the first component, such that the third component moves axially away from the first component, thereby causing the third component to move axially away from the second component, and
• wherein the indicator member is a lever arm pivotably connected to a rotationally fixed housing portion of the torque limiter and configured to move out of a first cavity in the housing portion of the torque limiter upon axial movement of the third component away from the first and second components, so as to provide a visual indication that the torque limiter has tripped upon inspecting the torque limiter.