The invention relates to a vibrator for acting on an object in a predetermined direction, comprising a casing and two identical, synchronously driven, electric linear motor coils arranged mirror-symmetrically therein, between which coils there is an armature which can be moved to and fro in an oscillatory fashion by driving the linear motor coils appropriately in their longitudinal direction, the armature being mounted via wires arranged under spring bias in the casing, and also to an apparatus for producing concrete blocks which uses vibrators of this type.
