Spiral advance/retreat actuation device

A spiral advance/retreat actuation device comprising:

• a first strip material including a first engagement structure along an extension direction in each of an upper edge side portion and a lower edge side portion;
• a second strip material including a second engagement structure along an extension direction in each of an upper edge side portion and a lower edge side portion, the second engagement structure being configured to be removably engageable with the first engagement structure;
• a strip material guide unit;
• and
• a strip material storage container, wherein:
• the first strip material and the second strip material are each wound spirally around a common axis in a state shifted from each other in a direction of the axis to constitute a cylindrical structure in which the first engagement structure in the upper edge side portion of the first strip material and the second engagement structure in the lower edge side portion of the second strip material are engaged with each other in such a manner as to retain the first strip material and the second strip material in a direction of overlapping surfaces and the first engagement structure in the lower edge side portion of the first strip material and the second engagement structure in the upper edge side portion of the second strip material are engaged with each other in such a manner as to retain the first strip material and the second strip material in a direction of overlapping surfaces with an inner surface of the upper edge side portion of the first strip material and an outer surface of the lower edge side portion of the second strip material partially overlapping each other in the direction of the axis and with an inner surface of the lower edge side portion of the first strip material and an outer surface of the upper edge side portion of the second strip material partially overlapping each other in the direction of the axis;
• the strip material guide unit is configured to guide the first strip material and the second strip material in a spiral manner, and enable the first strip material and the second strip material to transition between a separated state in which the first strip material and the second strip material are separated from each other and a cylindrical configuration state in which the first strip material and the second strip material constitute the cylindrical structure;
• the strip material storage container includes a first storage chamber that spirally stores the first strip material that has transitioned from the cylindrical configuration state to the separated state, and a second storage chamber that spirally stores the second strip material that has transitioned from the cylindrical configuration state to the separated state;
• and
• an inner bottom surface of at least one of the first storage chamber and the second storage chamber is inclined downward as the inner bottom surface extends away from the axis.