Abstract: The convertible skate includes wheels that are interchangeable between an in-line configuration and a conventional roller skate configuration. The skate can be readily changed between the different configurations by depressing a first button to release a latch and unlock the front pair of wheels from a first configuration. The front wheels can then be rotated into and locked by the latch at their second configuration. The same type of conversion method and apparatus can be used to convert the rear pair of wheels between different configurations. The skate may also include a reverse spinning brake that prevents the skate from rolling backwards. The reverse spinning brake works in either the in-line configuration or the conventional roller skate configuration without requiring any changeover process between configurations.

Abstract: An object sensor (or event detector) apparatus detects distinctive characteristics (such as color) of otherwise physically similar objects. Respective indices or counters are incremented in response to the various detections. The event detector (object sensor) may take various forms such as a conveyor belt production monitor, but is especially useful as an electronic scorekeeper for a competitive game which simultaneously keeps score for two or more different players by distinguishing between the different colors (or other characteristics) of balls or other objects each player uses to play a given game. A solitary mode also keeps score for a single player within a given time period. In this selectable alternative mode, the event detector apparatus records accumulated points and displays the time remaining in a given time period which defines a game time period.