Yamaha Hatsudoki Kabushiki Kaisha

Kazuo Aoi

Naoki Tsuchida

Masaaki Yoshikawa

Toshikazu Ozawa

Takanori Suzuki

An improved shifting device for the hydrostatic transmission of a lawn tractor or the like. The shifting device includes means for permitting a greater latitude of movement of the shift lever without effecting either forward or reverse movement. This is done by incorporating a linkage system for interconnecting the shift lever with the transmission control that includes a lost motion connection and by providing a leak path in the hydrostatic transmission so that a greater than normal pressure must be exerted before drive in one direction is possible.

Shifting device for lawn mower and the like

A valve placement arrangement for an internal combustion engine including at least three intake valves and two exhaust valves and wherein no two of the exhaust valves are adjacent to each other and they are separated by intake valves so as to insure against undue heating and minimize thermo-loading.

Valve arrangement for internal combustion engine

A combustion chamber configuration for an engine having three intake valves and two exhaust valves per cylinder. The combustion chamber configuration permits the use of stroke-to-bore ratios of 0.8 to 1 or less and compression ratios of 9 to 1 or greater while affording good flame travel in the combustion chamber. The piston is formed with a generally flat head that has semi-circular recesses for valve clearance.

Four-stroke internal combustion engine

A valve actuating mechanism for an internal combustion engine that permits the use of a plurality of valves per combustion chamber. There are a greater number of intake valves than exhaust valves and the intake valves are actuated by means of a single rocker arm associated with a first cam shaft. The exhaust valves are individually and directly operated by a second camshaft.

Valve actuating mechanism for internal combustion engine

Two embodiments of valve arrangements for internal combustion engines that permits the use of a plurality of valves for a given combustion chamber while operating all of the valves through a simplified camshaft arrangement. Some of the valves are operated directly by the cam lobes and others are operated by rocker arms. In addition, an embodiment is disclosed wherein a two rocker arm arrangement is employed for operating certain valves.

Actuating mechanism for multiple valve internal combustion engine

An internal combustion engine of the multiple valve type embodying an improved supporting arrangement for a camshaft that directly operates one valve and indirectly operates a pair of valves. The camshaft is provided with bearing surfaces on opposite sides of the cam lobes and a pair of bearing caps cooperate with the cylinder head for supporting these bearing surfaces. Each bearing cap and the cylinder head journal one of the bearing surfaces of the camshaft around its circumference and the other of the camshaft bearing surfaces are journaled only by the bearing cap and not by the cylinder head so as to afford clearance and yet adequate support.

Growing community of inventors

Hamamatsu, Japan

Kazuo Aoi