Abstract: A shock-absorbing polyurethane foam is formed of a polyol component and a polyisocyanate component. The polyol component is a mixed polyol having an average hydroxyl number of 130-250 and composed at least of 20-70 parts by weight of a low-molecular polyol having a molecular weight of 300-500 and 80-30 parts by weight of a high-molecular polyol having a molecular weight of 1,500-8,000 per 100 parts by weight of the whole polyol component. The foam further contains 5-150 parts by weight of a plasticizer having a solidification point not higher than -20.degree. C. per 100 parts by weight of the whole polyol component. The foam can be produced by reacting the polyol component and polyisocyanate component in the presence of 5-150 parts by weight of the plasticizer per 100 parts by weight of the polyol component.

Abstract: In a distribution type fuel injection system, the fuel injection advance angle, or the relative angular position at which fuel injection begins, is controlled by a first spring loaded piston (44). The spring force is opposed by pressurized fuel from a pump (14), the pressure increasing with engine speed. A second spring loaded piston (49) moves the first piston (44) to an advanced position for starting the engine and is retracted when the fuel pressure reaches a certain value to subsequently retard the advance angle in an idling speed range. The fuel pressure moves the first piston (44) to progressively advance the angle in a higher speed range. An electromagnetic valve (62) is controlled to trap fuel and apply a hydraulic lock to the second piston (49) during starting of the engine to prevent retarding of the advance angle until the engine speed or coolant temperature reaches a predetermined value.

Abstract: An engine driven air pump produces a vacuum having a magnitude or level which increases with engine speed. The air pump is connected to a pneumatic governor which varies the volume of fuel injected into the engine by a fuel injection pump in accordance with the level of vacuum. A control valve variably communicates the inlet of the governor with the atmosphere to control the level of vacuum. A high speed valve connected in series with the control valve progressively closes when the engine speed exceeds a predetermined maximum value. A shut-off valve connected in series with the control valve closes when an engine on-off switch is turned off.