Abstract: An image forming apparatus includes plural image holding bodies that are provided for respective colors of toners and hold toner images having the respective colors, an intermediate transfer body onto which the toner images having the respective colors held by the plural image holding bodies are transferred, a waste toner collection unit that collects toners remaining on the intermediate transfer body as a waste toner in a case where the toner images having the respective colors transferred onto the intermediate transfer body are transferred onto a recording material, a waste toner developing unit that uses the waste toner collected by the waste toner collection unit to develop a toner image on an image holding body of the plural image holding bodies or the other image holding body of the plural image holding bodies, and a control unit that performs a control to cause the waste toner developing unit to develop the toner image in a case where a predetermined condition about a ratio of a waste toner having each

Abstract: A system preventing the percolation of fuel in a carburetor comprising a first passage communicating a space of a float chamber of the carburetor with the atmosphere, a diaphragm valve with a vacuum chamber for closing the passage, and an inner vent pipe for communicating the space of the float chamber with an intake passage of the carburetor. A thermo sensor is provided for sensing the temperature of the carburetor and for producing a signal when the temperature reaches a high temperature which would cause the percolation of the fuel. The diaphragm valve is operated in dependency on the signal of the thermo sensor to open the passage to communicate the space of the float chamber with the atmosphere.

Abstract: A system for preventing percolation of fuel in a carburetor for a motor vehicle. The system is provided with air passages for communicating a float chamber of the carburetor to the air and to a canister filled with charcoal particles. Valves are provided in the passages for opening the passages, when the engine operation is stopped and the temperature of the fuel in the float chamber is high. A fan is provided for introducing the air into the float chamber and for discharging the air to the canister together with vapor of the fuel in the float chamber, thereby to promote the evaporation of the fuel to cool the fuel by the evaporative cooling.