Abstract: 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.

Abstract: A time variable thermostat comprising, a housing, a clock connected to the housing and having a shaft which is rotatable with time and a disc connected to the shaft for rotation with the shaft. The disc has a plurality of circumferentially spaced slots each extending radially of the disc. A temperature responsive switch has an actuator movable with a change of temperature and the switch includes contacts which are closed and open depending on a position of the actuator. A double control arm is connected to the actuator and is movable with respect to the housing about a center of rotation and a pin slidably mounted to each slot and having a stop portion extending beyond the disc against which the control arm is engageable to influence closing and opening of the contacts. One arm includes a pin engagement portion movable in an arc with movement of the arm about the center of rotation.

Abstract: A time variable thermostat for controlling a heater comprising, a temperature activated switch connected to the heater for deactivating the heater at a selected temperature having a movable contact and at least one fixed contact, the movable contact being moved into abutment with the fixed contact when a temperature other than the selected temperature is reached to activate the heater and moved into abutment with the fixed contact to deactivate the heater when the selected temperature is reached. A temperature selection arm is connected to the movable contact and associated with a scale for selecting the temperature at which the movable contact is moved out of abutment with the fixed contact.