Abstract: The aromatic heterocyclic copolymer is produced by (a) reacting (i) an aromatic diaminodithiol compound, hydrogen atoms of thiol groups of which compound are substituted with substituted or unsubstituted alkyl groups, with (ii) an aromatic diamino compound and (iii) a dicarboxylic acid derivative in an organic solvent, to produce a precopolymer; and (b) heating the precopolymer to cause a thiazole ring closure reaction. This aromatic heterocyclic copolymer is contained as a reinforcing polymer in a molecular composite material.

Abstract: A rotary throttle carburetor in which an air passage leading to the engine has a crossbore to receive a cylindrical rotary throttle having a throttle passage to regulate the air passage. A constant pressure device is mounted on the carburetor body directly below the rotary throttle and a short straight fuel passage connects a constant pressure chamber of said device with the throttle passage of the rotary valve. A fuel pump device can be mounted between the carburetor body and the constant pressure device to supply fuel to the constant pressure chamber and also to insulate the constant pressure device from the carburetor body to reduce vaporization.

Abstract: A rotary throttle valve carburetor in which the rotary valve is assembled with an operating lever, a needle valve and a carburetor body cover in such a way that the lever may be operated from opposite sides of the carburetor by orienting the assembly in the carburetor body in one of two positions 180.degree. apart. A cam is interposed between the operating lever and the cover to shift the rotary valve and the needle valve axially with rotation of the valves to regulate the needle valve relative to a fuel nozzle port.

Abstract: A supplementary fuel supply mechanism for internal combustion engines which is incorporated in a carburetor with a manually operated flexible dome to discharge fuel from a supplemental fuel chamber adjacent the air inlet of a carburetor. The device is designed so that it can be interposed between the carburetor body and the air inlet as an auxiliary unit optionally applied.

Abstract: A carburetor for small engines which can be used in all positions utilizes a cylindrical rotary throttle valve with a venturi opening and provides a porous material as a part of the throttle valve, either as the entire material for the valve, or as a sleeve surrounding the venturi portion. During idling the fuel which might collect in a pocket in the valve is absorbed into the porous material and sucked into the engine, thus avoiding the disadvantages of liquid fuel being dumped into the engine when the position of the carburetor is changed.

Abstract: In a carburetor for furnishing fuel to internal combustion engines and utilizing a cylindrical rotary throttle valve as the venturi of the mixing passage, the addition of a fuel retaining means of absorbent material to prevent the puddling of unused fuel during the idling cycle and thus avoiding the problem of an overrich mixture when the carburetor is moved to another position.

Abstract: An all-position carburetor having an air fuel mixing passage with a rotary throttle valve rotatably disposed in the carburetor body across the mixing passage. The throttle valve has an opening therethrough to provide a venturi passage in conjunction with the mixing passage. A by-pass groove is formed in the outer surface of the rotary valve on the bearing surface of the body to allow fuel which might otherwise accumulate in a pocket, in certain positions of the carburetor, to flow into the main air fuel mixture, thus avoiding overrich conditions when the carburetor is turned from one position to another.

Abstract: A fuel feed system having a fuel tank and a pump for pumping up fuel from said fuel tank and for feeding the same to a combustor, characterized in that there is provided between said fuel tank and said pump, a negative pressure actuating valve which is closed against fuel pressure in said fuel tank but opened by a negative pressure created by said pump.