Abstract: A valve lifter is activated selectively by one of a plurality of cams, either via displaceable rollers or via tappets having rotatable grooves on top, to provide discrete or stepwise multimode operation and deactivation. The hydraulic control is only an option since the pure mechanical control is adequate. Easy to retrofit into existing engines.

Abstract: A variable valve gear particularly for internal combustion engines, in which a control cam of a camshaft acts, by way of pair of swivellably coupled levers, to a valve to produce an adjustment of the valve stroke. The valve stoke can vary continuously from a maximum lift to zero lift while the valve clearance can remain unchanged.

Abstract: A variable valve gear particularly for internal combustion engines, in which a control cam of a camshaft acts, by way of pair of swivellably coupled levers, to a valve to produce an adjustment of the valve stroke. The valve stoke can vary continuously from a maximum lift to zero lift while the valve clearance can remain unchanged.

Abstract: An internal combustion engine is arranged with a piston-rod which is kept at a minimum thickness because it is secured on a pin which comprises slider means, sliding on slideways secured to the casing. As a result, the compactness of the combustion chamber, defined between the piston and the crankcase, as well as the valve area are both kept at a maximum, whether these valves are the intake and exhaust valves of a 4-stroke or the exhaust valves of a 2-stroke engine. Directly driven camshafts, inside the crankcase, provide a valve gear train of a minimum inertia and constitute available counterweight shafts in the case of a 2-cycle engine for balancing first order forces and first order moments.