Seat support device

A seat support device, comprising:

• a base member;
• a first swinging member;
• and
• a second swinging member to which a seat of a vehicle is fixed, wherein
• one of the base member and the first swinging member includes two first rail portions each first rail portion of the two first rail portions extending in an arc shape along a first direction,
• the other of the base member and the first swinging member rotatably supports a plurality of first rollers, the plurality of first rollers being in rolling contact with the two first rail portions, and the two first rail portions and the plurality of first rollers being configured to support the first swinging member with respect to the base member such that the first swinging member is swingable relative to the base member in the first direction,
• one of the first swinging member and the second swinging member includes two second rail portions each second rail portion of the two second rail portions extending in an arc shape along a second direction different to the first direction,
• the other of the first swinging member and the second swinging member rotatably supports a plurality of second rollers, the plurality of second rollers being in rolling contact with the two second rail portions, and the two second rail portions and the plurality of second rollers being configured to support the second swinging member with respect to the first swinging member such that the second swinging member is swingable relative to the first swinging member in the second direction,
• the plurality of first rollers includes rollers that respectively support a lower portion, an upper portion, and a side portion of each of the two first rail portions, and
• the plurality of second rollers includes rollers that respectively support a lower portion, an upper portion, and a side portion of each of the two second rail portions.