Input device, movable body, and steering shaft system

An input device comprising:

• a casing that includes a tubular portion in which an end portion of a column post is fitted, and to which an operation portion that a driver operates is attached, the column post rotatably supporting a steering shaft;
• a biasing member disposed between a brim portion and the column post in a central axis direction of the tubular portion, the brim portion being provided on an inside surface of the tubular portion;
• and
• a rotation restriction member that is disposed between the brim portion and the column post in the central axis direction of the tubular portion, and restricts rotation of the tubular portion in a circumferential direction relative to the column post,
• wherein:
• the tubular portion includes an engaging portion that engages, in the central axis direction, with an engaged portion of the column post,
• in a state in which the engaging portion is engaging with the engaged portion, the biasing member biases the brim portion in a direction in which the brim portion moves away from the column post, the direction being in the central axis direction,
• the rotation restriction member restricts rotation of the tubular portion by engaging with the brim portion in the circumferential direction and engaging with the column post in the circumferential direction, in a state in which the biasing member is located between the rotation restriction member and the brim portion,
• the rotation restriction member includes:
• a base;
• and
• a projection in contact with the column post, the projection projecting from the base,
• the rotation restriction member presses and elastically deforms the biasing member by the projection being in contact with the column post,
• the column post includes a first recess in which the projection is put, the first recess being recessed in a central axis direction of the column post,
• the first recess has a bottom surface, the bottom surface including a non-sloping bottom surface and a sloping bottom surface,
• the non-sloping bottom surface is substantially perpendicular to a central axis of the column post,
• the sloping bottom surface has a slope that increases a depth of the first recess with distance from the non-sloping bottom surface, and
• when the input device is attached to the steering shaft,
• the rotation restriction member presses and elastically deforms the biasing member by the projection of the rotation restriction member, which is put in the first recess and faces the sloping bottom surface, sliding along the sloping bottom surface and moving onto the non-sloping bottom surface along with rotation of the casing.