Electrocution proof line and extension cord

Abstract From the Canadian patent

A power line includes a plug having four wire connection sites and a line cord having four conductors each conducted to a respective wire connection site. Two of the sites are connected to the two power conducting blades of the plug and the remaining two wires are connected to a single grounding prong of the plug. An extension cord can be made by attaching a female socket to opposite ends of the wires the, female socket also having four wire connection sites. The plug and line cord can also be connected directly to a device having four wire connection sites.