Ford Motor Company Limited

Mechadyne Plc

Derek Frost

Timothy Mark Lancefield

Variable valve timing

Dual tract induction

Variable lift valves

The invention relates to a desmodromic system in which a valve stem is arranged to be acted upon directly, or by way of rockers, by an opening cam and a closing cam rotatable together at constant or varying angular velocity in synchronism with the rotation of the engine crankshaft, and in which a compliance device is incorporated in the transmission train from the cams to the valve stem, the compliance device comprising two cup-shaped members nested together with a limited relative movement between and resiliently urged away from one another, the compliance device operating to provide zero clearance when the valve is open and maximum clearance when closed to accommodate valve recession and thermal expansion.

Desmodromic valve system

An engine driven camshaft cam is driven in a manner to superimpose a variable oscillation on the cam as it is rotatably driven in order to vary the period during which an associated valve is opened, the drive including an engine driven gear or sprocket journalled in a block whose axis is displaceable transversely to the axis of the cam, a slider member secured for rotation with the gear and guided for linear radial movement relative to the gear or sprocket, and a rack on the slider member engaged by a pinion coupled to the cam for oscillating the cam relative to the camshaft upon sliding movement of the slider in response to eccentrically displacing the axis of the gear.

Cam drive mechanism

The invention relates to a drive mechanism for connecting an input shaft to an output shaft and superimposing on the output shaft a variable oscillatory motion determined by the position of a reaction member. The drive mechanism comprises an input disc fast in rotation with the input shaft, and defining a slideway transverse to the axis of the input shaft. A sliding member is made to slide along the slideway by a block journalled within a pivotable yoke, the block being itself slidable in a second slideway defined by the sliding member. A crank pin fixed to the output shaft is connected slidably to the sliding member such that as the sliding member slides along the slideway, the phase of the output shaft is varied with respect of the phase of the input shaft. A second similar mechanism drives a weight with opposite phase in order to cancel out the reaction torque on the input shaft.

Growing community of inventors

Leigh-on-Sea, United Kingdom

Derek Frost