Abstract: A yoyo capable to be manually accelerated when held by hands comprising two spinning bodies (1), a button (2) and a side cap (3) mounted at center positions of outer sides of the two spinning bodies (1) respectively, a manual acceleration mechanism provided inside the two spinning bodies (1) and connecting the two spinning bodies (1) as a whole, and a bearing (4) disposed between the two spinning bodies (1) for winding a yoyo string; two ends of the manual acceleration mechanism are connected with the spinning bodies (1); by pressing the button (2), the manual acceleration mechanism drives the spinning bodies (10) to spin. The yoyo has a wider range of utility satisfying the playing needs of kids and children and at the same time increasing the ways of playing the yoyo and thus the fun in playing the yoyo. Also, the yoyo allows players to create their own ways of playing the yoyo.

Abstract: A yoyo capable to be electrically accelerated when held by hands, characterized in that, it comprises two spinning bodies (1), a connector (2) connecting the two spinning bodies (1) as a whole, side shaft sleeves (3) provided at center positions of outer sides of the spinning bodies (1), an electrical acceleration mechanism provided inside the spinning bodies (1), and a bearing (4) disposed between the two spinning bodies (1) for winding a yoyo string. The electrical acceleration mechanism is connected to the spinning bodies (1). By pressing the side shaft sleeves (3), the electrical acceleration mechanism operates and thus drives the spinning bodies (1) to spin simultaneously. The side shaft sleeves (3) can be pressed to start spinning and accelerating the spinning bodies (1); when the spin speed is high enough, grab the yoyo string and then release the yoyo; the player can then have sufficient time to perform various yoyo tricks. Accordingly, even a short player can play the yoyo.

Abstract: The expanding and contracting yo-yo is a spool formed by a pair of disks connected by a narrow diameter pin having a string wound around the pin. At least one, and preferably both, of the disks has a plurality of overlapping wings (also referred to as air foils or leaves) pivotally attached to the periphery of the outer face of the disk. A biasing member causes the wings to remain in a closed dome configuration until the disks begin to spin. When the yo-yo is dropped and pulled back in, centrifugal force, centripetal force, alternate lift and drag of air flow, and resilient bias cause the wings to alternately pivot and unfold outward, followed by pivoting inward to a dome shape. In an alternative embodiment, the wings may be formed with a resilient living hinge that permits the wings to expand and contract against the body of the yo-yo.

Abstract: The invention is an improved yo-yo that has a rotatable, outwardly-facing roller on each of its two sides. Each roller has an outwardly-facing opening that is sized and shaped to facilitate a non-slip engagement between a finger and the roller. The opening also provides access to an O-ring that functions to secure the roller to the yo-yo.

Abstract: A yo-yo incorporates a construction that enables the gap between the yo-yo halves to be adjusted simply and quickly. The halves of the yo-yo are threadably mounted on the ends of the yo-yo axle. The yo-yo halves are biased apart axially to maintain firm frictional contact between the yo-yo halves and the axial. The gap may be adjusted simply by rotating the yo-yo halves with respect to each other. The inwardly facing surfaces of the yo-yo halves also incorporate angular relationships to facilitate yo-yo play.

Abstract: A yo-yo having a pair of rotation bodies spaced from each other by a shaft, with the shaft means having a string connected thereto. Mechanisms are provided between the shaft and the rotation bodies such that: the shaft is fixed with respect to the rotation bodies as the string is unwound and the yo-yo travels downward; the shaft my rotate with respect to the rotation bodies for a selected number of rotations when the string has been completely unwound; and the shaft is fixed with respect to the rotation bodies after completion of the selected number of rotations and may therefore rewind the string to return the yo-yo to the user's hand. This mechanism may take various forms, including gears, locking tines, and tape reels.

Abstract: A self-defense device comprising a spherical member and a tether cord. The tether cord is wound on a self-winding spool that is rotatably attached to the interior of the spherical member. The free end of the tether cord has a loop formed thereat for securing the device to a person's wrist. The spherical member may have an outer lining of elastic material or may have a plurality of barbs on its exterior surface.

Abstract: A winding and launching device for toy vehicles which includes a base covered by a shell, the shell having a shaft projecting therefrom and being adapted to mate with a coupling on a flywheel-driven toy vehicle for rotating the flywheel. The shaft is rotated at high speed through a step-up gearing arrangement by a crank positioned on the shell. A button protrudes from the shell and is connected to a platform which holds the shaft in place, depressing the button pulls the shaft from the vehicle coupling so that the vehicle may speed away.