The toy comprises a small inner sphere with a number of pivotally mounted arms covering its surface. When two opposed outer shells move towards the inner sphere, the arms pivot from a longitudinal direction to a radial direction. (see illustration)

The two opposed outer shells are connected with a spring which pulls them together. The outer shells can be pulled apart by the user and locked into the cylindrical configuration.

This toy can be used for many different applications.

If the device were covered with a flexible sheet it could be used as a collapsible ball.

One hemisphere covered with a flexible sheet could be used as an umbrella.

I initially thought of it as a cool firework: a mortar fires the device into the sky in its cylindrical (or spear) configuration. At the apex of its trajectory the device then pops into its spherical configuration. Fireworks are attached tangentially to the sphere so that the sphere rotates as it falls to Earth.