ABSTRACT
The “interlock” and “lockout” are sometimes used interchangeably. However, there is a subtle difference between the two. A “lockout” usually refers to a protective mechanism that cannot be overridden during a phase of product use. The quintessential lockout is a lock. Locks can be added to many different types of products to prevent unauthorized use, as well as to protect people from something hazardous. Lockouts are a common feature of amusement park rides, such as roller coasters. A breathalyzer linked to an automobile’s ignition system is an example of a lockout, preventing the engine from starting if the operator has consumed too much alcohol according to the legal limit. The lockout prevents ill-advised attempts to add or remove items when the moving drum could cause harm or, in the case of the washer, an escaping wave of hot, detergent-laden water could cause skin and eye injuries.
