Abstract: An engine comprising a main intake passage having a throttle valve therein. A bypass passage is branched off from the main intake passage located upstream of the throttle valve and is connected to the main intake passage located downstream of the throttle valve. A flow control valve, actuated by a step motor, is arranged in the bypass passage. When the engine is operating in an idling state, the step motor is rotated at a first speed in a rotating direction wherein the engine speed approaches a desired engine speed. When the ignition switch is turned to the OFF position for stopping the engine, the step motor is rotated at a second speed which is lower than the first speed a little while after the flow control valve fully opens the bypass passage.

Abstract: An idling speed control device of an internal combustion engine comprising a bypass passage which interconnects the intake passage located upstream of the throttle valve to the intake passage located downstream of the throttle valve. A flow control valve is arranged in the bypass passage and actuated by a step motor for controlling the amount of air flowing within the bypass passage to maintain the idling speed of an engine at a predetermined speed.

Abstract: Molding tobacco filters having a variety of cross-sections which are practically useful in providing various preferable effects such as improvement in pressure drop, balanced adsorption of smoke component or the like, are provided according to a method which is characterized in forming fiber bundles of composite fibers consisting of a first and a second component by themselves, or a mixture of at least 20% by weight (based upon the total fiber mixture) of said composite fibers and another kind of fibers so as to give a variety of cross-sections to said fiber bundles, and subjecting said fiber bundles to heat-treatment at a temperature lower than the melting point of the first component but higher than the melting point of the second component to stabilize the structure by the self-adhesion of the second component; the first component of a fiber forming polymer and the second component consisting of one or more kinds of polymer having a melting point lower than that of the first component by 10.degree. C.