Patent ID: 8027575

Claim:
A heater suitable for use with an air treatment chemical dispenser, the heater comprising: a housing having a base and a cover, the base and cover together defining an internal generally ring-shaped cavity and an axial through bore; a first arc-shaped electrical contact positioned in the cavity; a second arc-shaped electrical contact also positioned in the cavity and having a portion overlapping the first arc-shaped electrical contact, and having another portion which does not overlap the first arc-shaped electrical contact; a heating element sandwiched between the first and second electrical contacts at a position where the first and second electrical contacts overlap; and a spring positioned adjacent at least one of the first and second electrical contacts to bias that contact towards the heating element while also allowing for adjustment if thermal expansion of the housing occurs when the heating element is generating heat; wherein the first and second arc-shaped electrical contacts do not overlap over a majority of a plan view area of the first arc-shaped electrical contact.