A multi-function yo-yo comprising:
- an axle having a first axis of cylindrical symmetry and an axle mass, said first axis defining an axial direction parallel to said first axis, and defining, for a point off said first axis, a radial direction along a direction perpendicular to said first axis and passing through said point, and defining, for said point off said first axis, an azimuthal direction, perpendicular to said first axis and said radial direction and passing through said point;
- a first fly disk centrally mounted at a first end of said axle, said first fly disk having a first mass substantially larger than said axle mass, and having a second axis of cylindrical symmetry coincident with said first axis of cylindrical symmetry;
- a second fly disk centrally mounted at a second end of said axle, said second fly disk having a second mass substantially larger than said axle mass, and having a third axis of cylindrical symmetry coincident with said first and second axes of cylindrical symmetry;
- an axle sleeve surrounding a central portion of said axle and being rotatable with respect to said axle;
- a string tethering said axle sleeve;
- a first rotational-speed governor movably mounted in said first fly disk and having a first sleeve grip, said first governor having spring biasing towards a radially inwards position where said first sleeve grip contacts said axle sleeve, and said first governor being thrown by centrifugal force to a radially outwards position when said first fly disk rotates about said axle axis with sufficient speed, and when said first governor is in said radially outwards position said first sleeve grip is drawn away from contact with said axle sleeve;
- and
- a function switch on an exterior surface of said first fly disk, when said function switch is in a first switch position said first governor is locked in said radially inwards position so that said first sleeve grip contacts said axle sleeve and the yo-yo acts as a fixed axle yo-yo, when said function switch is in a second switch position said first governor is locked in said radially outwards position so that said first sleeve grip does not contact said axle sleeve and the yo-yo acts as a free axle yo-yo, and when said function switch is in a third switch position said first governor is free to move between said radially inwards position and said radially outwards position in response to a combination of said spring biasing and said centrifugal force and the yo-yo acts as a centrifugal-clutch yo-yo.