Patent ID: 7352960

Claim:
A heating device for the vaporization of active substances, in which a wick that is immersed in a fluid active substance is heated to produce vaporization of the active substance, said heating device comprising: a plastic housing having a front side and a back side and an open bottom for receiving a refill bottle, a refill bottle unit containing said active substance and including a wick in fluid communication with said active material, said refill bottle being positioned in said housing with said wick extending out the top of said bottle and upwardly in said housing, an elongate longitudinally extending plastic frame, positioned in said housing in proximity to said bottle and wick, with its longitudinal axis parallel to the longitudinal axis of said wick, a circular heating ring hingedly connected to the upper end of said plastic frame and configured to be bent over the top of and to encircle said wick, at least one electric resistance element being positioned on the interior of said circular heating ring, said resistance element being fitted with a pair of resistance wire leads, said longitudinally extending frame having at least one longitudinally extending rib for providing at least a pair of longitudinal channels, and being fitted at its lower end with a pair of electrical prongs in a plug unit for use in an electrical outlet, said electrical prongs in said plug unit extending outwardly through the back side of said housing, said pair of electrical resistance wire leads extending from said resistance element, each wire being positioned in a separate one of said channels and being connected to respective prongs in said plug unit, and at least one projection on the body of said circular heating ring adjacent the said hinge, to guide the respective resistance wire leads through the hinge area and into separate longitudinal channels.