Known devices for providing security to prevent unauthorized individuals from using electrical appliances have included means such as large expensive lockable coverings for the entire appliance or switch or other devices built into the appliance itself. These prior devices have tended to be bulky and hard to handle, or relatively expensive and complicated. Furthermore, in appliances not initially provided with some type of security at the factory, the addition of a security device was extremely costly or difficult and usually involved tools or knowledge of the appliance not readily available.
USPTO Backgrounds
USPTO Backgrounds