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US 4,380,216 AGranted
Economical engine construction
AssigneeTecumseh Products Company
InventorWilliam C. Kandler
Life of this patent
Estimating the term…
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AssigneeTecumseh Products Company
InventorWilliam C. Kandler
Estimating the term…
An improved engine construction is disclosed having a valve train including valves and corresponding valve stems for controlling the intake and exhaust ports, cams for imparting reciprocating motion to the valves by way of the valve train, and a valve spring for biasing each valve toward its closed position and the valve train into tracking relation with the cam. The only element of the valve train coupling a cam to a stem is a cam follower with a depression for receiving the corresponding stem end and a cam engaging surface opposite the depression with the cam follower being held captive intermediate the stem and cam solely by the spring biasing of the stem toward the cam and the engagement of the stem end and the depression. The spring biasing is provided by a coiled wire spring having outwardly extending legs each of which engages a corresponding stem to urge the valves toward their closed position. The bight or coiled portion of the spring is held in a relatively fixed position by a portion of the engine casting.
In an internal combustion engine having a valve train including a pair of stems and valves connected to each of the stems for controlling intake and exhaust ports respectively of the engine, cams for imparting reciprocating opening motion to each valve by way of the valve train, and a spring for biasing the valves closed and the valve train into tracking relation with the cams, the improvement wherein the spring comprises a coiled wire spring having an anchored central bight portion and outwardly extending legs, each engaging one of the pair of stems to urge the respective valves toward a closed position, the cams for imparting reciprocating motion comprising a pair of non-metallic radial cam surfaces shaft driven by a like pair of non-metallic spur gears, the cams being driven by a common spur gear fixed to the crankshaft of the engine which gear meshes with each of the like pair of gears.
In an internal combustion engine having intake and exhaust ports, and a valve train having a sole coupling element and including a stem and a valve connected to one end of the stem and controlling one of the intake and exhaust ports of the engine, a cam for imparting reciprocating opening motion of the valve by way of the valve train, and a spring for biasing the valve closed and the valve train into tracking relation with the cam, the improvement wherein the sole element of the valve train coupling the cam and the stem comprises a non-metallic cam follower having a depression for receiving the stem end opposite the valve and a cam engaging surface opposite the depression, the cam follower being guide-free and held in position intermediate the stem and cam solely by the spring biasing of the stem toward the cam and the engagement of the stem end and the depression.
In an internal combustion engine having intake and exhaust ports, and a valve train having a sole coupling element and including a stem and a valve connected to one end of the stem and controlling one of the intake and exhaust ports of the engine, a cam for imparting reciprocating opening motion to the valve by way of the valve train, and a spring for biasing the valve closed and the valve train into tracking relation with the cam, the improvement wherein the sole element of the valve train coupling the cam and the stem comprises a cam follower having a depression for receiving the stem end opposite the valve and a cam engaging surface opposite the depression, the cam follower being held captive in position intermediate the stem and cam solely by the spring biasing of the stem toward the cam and the engagement of the stem end and the depression.
In an internal combustion engine having a valve train including a pair of stems and valves connected to each of the stems for controlling intake and exhaust ports respectively of the engine, cams for imparting reciprocating opening motion to each valve by way of the valve train, and a spring for biasing the valves closed and the valve train into tracking relation with the cams, the improvement wherein the spring comprises a coiled wire spring having an anchored central bight portion and outwardly extending legs, each engaging one of the pair of stems to urge the respective valves toward a closed position and further comprising a guide-free cam follower captive intermediate a stem and corresponding cam.
Dependencies are inferred from the claim text.