Handheld cordless hair dryer

摘要

A handheld cordless hair dryer utilizes a battery powered fan for directing a flow of air through a nozzle body portion within which a heat exchanger is disposed in heat exchange relationship with respect to both the airflow and heat generated by a gas combustion device. To provide a highly efficient transference of heat from the gas combustion device to the airflow, while avoiding high temperature conditions in exhaust gases discharged or at the peripheral wall of the nozzle body portion, the heat exchanger is comprised of a heat conductive inner duct and an outer duct between which conductive vanes extend, the outer duct being in spaced relationship with respect to an inner surface of the peripheral wall of the nozzle body portion and the inner duct serving as both a combustion tube and an exhaust duct for the gas combustion device. To provide a simple and safe operation, a single manually shiftable switch is actuatable in response to manually applied pressure exerted by the hand of a user grasping the handle body portion, the switch means being designed to automatically return to a deactivating position upon removal of the manually applied pressure, and a locking arrangement being provided to prevent inadvertent shifting of the switch into its activating position. Furthermore, a safety shutoff valve arrangement are provided for terminating the flow of gas to the gas combustion device when unsafe temperature levels result in the heat exchanger and whenever a flame is not produced or is extinguished after being produced.