US Patent 7298240 Electronically enabling devices remotely

A device has (1) an electronic key that transmits a wireless coded signal and (2) at least one tool that can receive that signal. The coded signal is compared to a coded signal stored in said tool. If the coded signal matches the stored signal, a switch is closed for a predetermined amount of time. An on/off switch then enables the user of the tool to turn the tool on and off during the predetermined amount of time. After the predetermined amount of time, the switch is opened so that the tool can no longer be used. Opening the switch may be delayed if the tool is in use. The tool may also contain a unique identification code that can be read by various electronic means to identify the tool.