Abstract: A number of embodiments of variable valve actuating systems wherein the valve is operated selectively by either first or second rocker arms both of which are supported for pivotal movement on the same rocker arm shaft but which are operated by different cams and have different lifts. Only one of the rocker arms directly operates the valve. The lift is changed by selectively coupling the rocker arms for simultaneous operation. A number of variations in locations and valve actuation are disclosed as well as a variable induction system that cooperates with the variable valve actuation to improve the engine performance over a wider range of speeds and loads. The coupling between the rocker arms includes a replaceable adjusting shim.

Abstract: A number of embodiments of variable valve actuating systems wherein the valve is operated selectively by either first or second rocker arms both of which are supported for pivotal movement on the same rocker arm shaft but which are operated by different cams and have different lifts. Only one of the rocker arms directly operates the valve. The lift is changed by selectively coupling the rocker arms for simultaneous operation. A number of variations in locations and valve actuation are disclosed as well as a variable induction system that cooperates with the variable valve actuation to improve the engine performance over a wider range of speeds and loads.

Abstract: A feedback control system for a gaseous fuel supplied internal combustion engine wherein the air-fuel ratio is maintained at a stoichiometric ratio by mixing air with the gaseous fuel supply to the charge former. A manually controlled air bleed is incorporated to permit adjustment for deterioration in the system due to age or carbon deposits or the like. In addition, the feedback control position of the air bleed valve is memorized, and the memorized value is utilized for control under some conditions when feedback control would not be appropriate, such as for cold starting when the sensor is not at its operating temperature or upon the resumption of normal control after a fuel shutoff during decell.

Abstract: Several embodiments of engines and systems for fueling engines to reduce the emission of unwanted exhaust gas constituents and to improve the fuel economy of the engine. A catalytic converter is provided in the exhaust system and a gaseous fuel is used at least during starting so as to bring the catalytic converter up to its operating temperature rapidly without necessitating the provision of an enriched fuel/air mixture. An oxygen sensor is employed in the exhaust system and a feedback control system varies the fuel/air ratio of the engine during its running in response to the output of the oxygen sensor. In order to test that the oxygen sensor is at its operating condition before feedback control is initiated, a rich fuel mixture is supplied and this rich fuel mixture is discontinued immediately upon the receipt of a signal from the oxygen sensor indicating that a rich mixture exits. Applications of the principal to both air valve type of carburetors and conventional carburetors are disclosed.

Abstract: Several embodiments of engines and systems for fueling engines to reduce the emission of unwanted exhaust gas constituents and to improve the fuel economy of the engine. A catalytic converter is provided in the exhaust system and a gaseous fuel is used at least during starting so as to bring the catalytic converter up to its operating temperature rapidly without necessitating the provision of an enriched fuel/air mixture. An oxygen sensor is employed in the exhaust system and a feedback control system varies the fuel/air ratio of the engine during its running in response to the output of the oxygen sensor. In order to test that the oxygen sensor is at its operating condition before feedback control is initiated, a rich fuel mixture is supplied and this rich fuel mixture is discontinued immediately upon the receipt of a signal from the oxygen sensor indicating that a rich mixture exits. Applications of the principal to both air valve type of carburetors and conventional carburetors are disclosed.

Abstract: A measuring apparatus of the present invention measures the constituent concentration of a specimen after loading into the apparatus a test piece having a test material which develops coloring as a result of a reaction with the constituents of a specimen. When the apparatus detects that the test piece having the test material has been loaded, it automatically begins to measure the constituent concentration of the specimen. That is, after the loading of the test piece is detected, a predetermined time period is measured. During this time measurement, the time period is displayed at a predetermined time interval. After the time measurement of this predetermined time period is terminated, the test material is irradiated with a light, and the intensity of the light from the test material is detected. The constituent concentration of the specimen applied to the test material can be determined on the basis of the reflected light intensity thus detected.

Abstract: The present invention is an apparatus for measuring the constituent concentration of a specimen on the basis of the color change in a test material housed in a test piece, which has reacted because of the specimen. The apparatus irradiates the test material which is a test piece loaded in the apparatus's main body and detects the intensity of the light reflected by the test material. A detection signal detected in the above way is sampled in a time period before and after the measurement timing at which the test material changes in color because of the specimen. An average value of the sampled detection signals is determined. The constituent concentration of the specimen is computed by referring to a stored conversion table on the basis of the average value determined in the above way.

Abstract: A throttle positioning device for prevent rapid closure of the throttle valve of an internal combustion engine under extreme decel conditions. The throttle control device includes a vacuum motor that is responsive to the pressure in the induction system at a point just slightly upstream of the throttle valve of the engine so that vacuum will be exerted on the vacuum motor when the throttle valve is substantially opened from its idle position and atmospheric pressure will be exerted when the throttle valve is closed toward its idle position. Various arrangements are provided for adjusting the rate of air flow between the vacuum motor and the intake passage in different directions.