PURPOSE: To enable preventing of a safety valve from sliding off accurately even when a tensile force is applied onto the valve by forming a step part on a base body of the safety valve to let outside air flow into a dust collection chamber when the pressure of the dust collection chamber falls below a specified value so that the step part contacts a circular rib formed at a mounting part of the safety valve to lock it.
CONSTITUTION: A safety valve to be set in a housing chamber 11 formed between a recessed part 10 of a dust collection lid and a cover 20 lets outside air flow into a dust collection chamber to prevent overheating of an electric blower 6 when the pressure in the duct collection chamber falls below a specified value. A cap 28 made of an elastic material having a suction port 29 mounted on a base body 24 set communicating with the dust collection chamber while having an opening part and the suction port 29 is closed by a float 32 built in the base body 24. A circular rib 16 is formed on a mounting part 15 of the body of an electric vacuum cleaner while a step part 25 is formed on the outer circumference of the base body 24 so as to contact the circular rib 16. A cover part 30 is formed on the cap 28 to cover a contact part between the circular rib 16 and the step part 25.
SAITO KAZUO
KOBAYASHI TOSHIZO
HIGUCHI SHUICHI
NISHIZAWA MITSURU
FUJIYOSHI TOSHIYUKI
