Arm-type assistance device

An arm-type assistance device, comprising:

• a pillar that includes an axis extending in a vertical direction;
• a first support portion that is supported by an upper end of the pillar so as to be rotatable in a horizontal direction;
• a first arm that includes a proximal end portion, the proximal end portion being supported by the first support portion so as to be swingable in the vertical direction;
• a second support portion that is supported by a distal end portion of the first arm so as to be swingable in the vertical direction;
• a second arm that includes a proximal end portion, the proximal end portion being supported by an upper end of the second support portion so as to be rotatable in the horizontal direction;
• a third arm that extends downward in the vertical direction from a distal end portion of the second arm;
• an operating unit that is supported by a lower end of the third arm so as to be rotatable in the horizontal direction;
• and
• a cargo holding unit that is integrated with the operating unit, wherein
• the first arm includes:
• a first member that includes a first end portion and a second end portion, the first end portion being supported by the first support portion so as to be swingable in the vertical direction, and the second end portion being supported by the second support portion so as to be swingable in the vertical direction;
• a first air cylinder that is configured to swing the first member relative to the first support portion;
• and
• a second member that extends parallel with the first member and includes a first end portion and a second end portion, the first end portion being supported by the first support portion so as to be swingable in the vertical direction, and the second end portion being supported by the second support portion so as to be swingable in the vertical direction,
• the first support portion, the first member, the second support portion, and the second member form a parallel linkage, the parallel linkage being assisted by operation of the first air cylinder,
• the arm-type assistance device further comprises a controller that is configured to control pressure of the first air cylinder,
• the third arm includes a second air cylinder, a pressure of the second air cylinder being controlled by the controller,
• the second air cylinder includes a piston rod that includes a protruding end, the protruding end supporting the operating unit, and
• a dimension in an axial direction of the second arm is greater than a dimension in an axial direction of the first arm.