Dual-parallel actuator piston interface

An actuator apparatus comprising:

• a piston assembly comprising a piston rod defining a longitudinal cavity having a first opening at a piston rod end and a second opening at a second piston rod end longitudinally opposite the piston rod end, wherein the longitudinal cavity extends through the second opening;
• an end assembly defining an aperture configured to receive the piston rod end;
• and
• a retaining cap assembly configured to affix to the piston rod end, abut the end assembly along a side surface of the retaining cap assembly when affixed to the piston rod end, and retain the piston rod end within the aperture such that at least a portion of the end assembly bears against the retaining cap assembly and against an outwardly-projecting shoulder of the piston rod, wherein the side surface is parallel to a longitudinal direction of the piston rod;
• wherein the retaining cap assembly comprises a cap end, and wherein the end assembly extends away from the piston rod end to a distal end disposed at a distance from the piston rod end that is greater than a distance between the distal end and the cap end.

An actuator apparatus comprising:

• a first piston assembly comprising a first piston rod having a first piston rod end;
• a second piston assembly arranged substantially parallel to the first piston assembly and comprising a second piston rod having a second piston rod end;
• an end assembly defining a first aperture configured to receive the first piston rod end, and a second aperture configured to receive the second piston rod end;
• a first retaining cap assembly configured to affix to the first piston rod end, abut the end assembly when affixed to the first piston rod end, and retain the first piston rod end within the first aperture;
• a second retaining cap assembly configured to affix to the second piston rod end, abut the end assembly when affixed to the second piston rod end, and retain the second piston rod end within the second aperture
• a longitudinal piston rod recess defined in an outer surface of the first piston rod;
• a longitudinal end assembly recess defined in the first aperture;
• and
• an anti-rotation key arranged at least partly within the longitudinal piston rod recess and at least partly within the longitudinal end assembly recess.