Movable apparatus, movable sheet, and method of manufacturing movable apparatus

A movable apparatus comprising a pivot joint of a walking assistance or robotic exoskeleton, comprising:

• a first frame component comprising a holding body comprising:
• a socket housing having an internal cavity;
• a first opening comprising a first elongated guide slot radially-extending through a sidewall of the socket housing into the internal cavity;
• a second opening comprising a second elongated guide slot radially-extending through the sidewall of the socket housing, the first and second openings being circumferentially-spaced and aligned within a single plane;
• and
• a shaft-shaped connection member extending from the socket housing opposite the first and second openings and functioning as a frame component;
• and
• a second frame component comprising a movable body comprising:
• a spherical ball pivotably disposed within the internal cavity of the holding body socket housing;
• a first movable shaft extending from the spherical ball through the first opening and functioning as the frame component, movement of the first movable shaft within the first elongated guide slot limiting rotation of the spherical ball to a predetermined angle within a single plane;
• and
• a second movable shaft extending from the spherical ball through the second opening and functioning as a stopper, movement of the second movable shaft within the second elongated guide slot limiting rotation of the spherical ball to the predetermined angle within the single plane and preventing rotation of the spherical ball about an axis of the first moveable shaft,
• wherein the spherical ball is fully enclosed within internal cavity of the socket housing, and the socket housing is formed around the spherical ball as a single piece member by an addictive manufacturing process;
• a first spring coupled between the first movable shaft and the shaft-shaped connection member of the first frame component to bias a position of the first movable shaft to a desired position within the first opening;
• and
• a second spring coupled between the second movable shaft and the shaft-shaped connection member to balance a tension force of the first spring and to prevent the first movable shaft of the second frame component from falling due to gravity.