Parallel link mechanism

A parallel link mechanism comprising:

• a first movable body and a second movable body positioned on the same virtual line;
• a first parallel link portion having a first base end and a first tip end and swingably connected at the first base end to the second movable body;
• a second parallel link portion having a second base end and a second tip end and swingably connected at the second base end to the first tip end of the first parallel link portion;
• a first arm portion having a third base end and a third tip end, rotatably connected at the third base end to the first movable body, and rotatably connected at the third tip end to the second parallel link portion at a first intermediate position between the second base end and the second tip end;
• a second arm portion having a fourth base end and a fourth tip end, rotatably connected at the fourth base end to the second movable body, and rotatably connected at the fourth tip end to the first arm portion at a second intermediate position between the third base end and the third tip end;
• and
• linear motion means capable of moving the first movable body and the second movable body individually along the virtual line, wherein,
• the first parallel link portion includes a first link member rotatably connected at one end to the second movable body, a second link member rotatably connected at one end to the second movable body, and a third link member connected to other ends of the first and second link members,
• the second parallel link portion includes a fourth link member and a fifth link member, with the fourth link member being rotatably connected at one end to the other end of the first link member and rotatably connected at another end to an end-effector, and the fifth link member being rotatably connected at one end to the other end of the second link member and rotatably connected at another end to the end-effector,
• the first link member, the second link member, and the first arm portion are parallel to one another,
• the fourth link member, the fifth link member, and the second arm portion are parallel to one another,
• the third link member, a line defined on the second movable body by connecting two rotation axes, and a line defined on the end-effector by connecting two rotation axes are parallel to one another,
• distancing between the fourth base end and the fourth tip end is equal to distancing between the third base end and the second intermediate position, and
• the fifth link member and the end-effector are connected at a point in the same plane as the second intermediate position, the plane being perpendicular to the virtual line.