Hand operated welder for thermoplastics - comprises handle with heating cartridge and switch which reduces current to lower level after time delay

摘要

Hot air gun has a handle with an electric cartridge for heating an air stream fed in via a tube. Heated air is directed by a nozzle onto the welding area. Manually operated switch on the handle controls current supply to the heating cartridge. When the switch is released, e.g. during a pause in operation, a time delay occurs before the current is reduced to a lower level. Current redn. after a given delay, approx. 3 mins., is not reduced to zero, but maintained at an average value below the working temp.. An air flow sensor in the form of a flap is located in the air feed pipe and is connected to a microswitch. When the air flow fails without a time delay or completely, current to the heater cartridge is switched off to prevent overheating. Heater cartridge is enclosed by a perforated plate (8) to prevent contact by hand. USE/ADVANTAGE - For hand welding thermoplastics materials. Uses less energy during breaks in operation.