Abstract: A ferromagnetic actuator having, in a housing, a ferromagnetic circuit defining an axial travel interval for an armature (22) of ferromagnetic material for axially driving a rod between two extreme positions in which the armature bears against poles of the ferromagnetic circuit, resilient return means provided to hold the valve at rest in a middle position between the extreme positions, and at least one coil carried by the circuit and enabling the armature to be brought in alternation into both positions. The rod carries a radially-magnetized bar of length not less than the travel distance of the armature, and the housing carries at least one magnetic flux sensor placed in a zone having low exposure to the field created by the coil(s).

Abstract: The apparatus for controlling valves that move linearly along respective axes comprises a number of actuators that is equal to the number of valves. Each actuator has an armature (22) of ferromagnetic material fixed to a valve push rod (24) and movable in a housing (16) of the actuator by a coil mounted on a ferromagnetic circuit. The ferromagnetic circuits of the two actuators allocated to two valves of the same type for a single cylinder are contained in the same housing.

Abstract: The electromagnetic valve actuator has an armature (22) of ferromagnetic material fixed to the stem of the valve, springs are provided to hold the valve at rest in a middle position between a fully open position and a closed position, and a single coil (38) is mounted on a ferromagnetic circuit. In combination with the armature, the magnetic circuit presents two stable magnetic flux paths both of which correspond to an airgap of small size.

Abstract: The invention concerns a valve controlling device with linear displacement along an axis comprising a number of actuators equal to that of the valves. Each actuator has a ferromagnetic blade fixed to a valve push rod and at least a return spring whereof one end is supported against the rod and the other end is supported against fixed anchoring means, adjustable in position relative to a housing of the actuator. A passage is provided between the actuators of the two adjacent valves to allow through an adjusting tool.

Abstract: The electromagnetic valve actuator has a valve drive armature and return springs provided to hold the valve in a determined rest position substantially halfway between two extreme positions namely a valve closed position and a valve open position. An electromagnetic unit has a ferromagnetic core placed on both sides of the armature and a power supply circuit. The power circuit calculates the velocity with which the armature approaches each of its extreme positions by measuring the current flowing through the electromagnetic unit and it applies a current to the electromagnetic unit which servo-controls variation of the velocity for compliance with a determined reference profile.

Abstract: To measure, in a reference frame, angular displacements of a privileged axis tied to a carrier, angular velocities or angular increments of the carrier are measured about two axes tied to the carrier, which axes are orthogonal to each other and at an angle of about 90.degree. the privileged axis. Said mutually orthogonal axes are caused to rotate at high speed about said privileged axis. The angular positions of said mutually orthogonal axes about the privileged axis are determined continuously relate to a reference position. Their angular displacements are calculated by integrating their angular velocities while taking account of said angular positions of the orthogonal axes about the privileged axis.