Safety device for an electrical plug and receptacle

A safety device for use with an electrical plug having a terminal that may be releasably engaged with an electrical receptacle with a plug securing means, the device comprising:

• (a) a tubular lock-in member slidably disposed over the electrical plug;
• (b) a retainer member;
• (c) a keyed lockable means for releasably securing the retainer member to the lock-in member;
• and
• (d) a lock-out member,
• wherein when the terminal is engaged with the receptacle with the plug securing means, the device may be placed in a lock-in mode wherein:
• (e) the lock-in member is in a lock-in position wherein the lock-in member obstructs the release of the plug securing means;
• and
• (f) the retainer member engages the receptacle or a part attached to the receptacle to prevent the lock-in member moving away from the lock-in position and the keyed lockable means secures the retainer member to the lock-in member;
• and wherein when the terminal is disengaged from the receptacle, the device may be placed in a lock-out mode wherein:
• (g) the lock-out member engages and obscures the plug securing means, and obstructs contact between the terminal and the receptacle;
• and
• (h) the lock-out member is secured to the lock-in member by the retainer member and the keyed lockable means.