Patent ID: 7137375
Filing Date: 2006-11-21
Classification: F01L

Abstract:
1. A four stroke engine comprising an engine body defining a cylinder bore, a piston reciprocally disposed within the cylinder bore and defining a combustion chamber with the engine body and the cylinder bore, a crankshaft coupled to the piston so as to rotate with a movement of the piston, at least one valve movable between a closed position and at least a first open position, the combustion chamber being open when the valve is moved to the first open position, a camshaft driven by the crankshaft, the camshaft having a cam portion to move the valve, a decompression member disposed on the camshaft, the decompression member being movable between a first position and a second position, a portion of the decompression member being configured to place the valve generally at the first open position when the decompression member moves to the first position and releasing the valve from the first open position when the decompression member moves to the second position from the first position, a regulating member carried by the camshaft, the regulating member movable between a regulating position and a non-regulating position where the regulating member regulates movement of the decompression member when the regulating member is at its regulating position, the regulating member releasing the decompression member from the first position when the regulating member is at its non-regulating position, and a bias member arranged to urge the regulating member toward its regulating position, the regulating member being configured so as to move toward the non-regulating position against the urging force of the bias member when a rotational speed of the camshaft exceeds a predefined speed; wherein the camshaft defines a first aperture and a second aperture, the first and second apertures at least partially intersect with each other, and the decompression member extends through a first aperture and the regulating member extends through the second aperture to cross the decompression member and wherein the first aperture and the second aperture cross generally normal to each other.