Abstract: 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.

Abstract: The invention relates to a concrete-block-making machine having a part which is displaceable via a linear drive, the linear drive comprising a drive unit and a linear guide for guide rollers, the drive unit comprising at least one linear motor and the linear guide comprising at least one guide rod for the guide rollers, the at least one guide rod and the guide rollers movable relative thereto being hardened, and guide rollers and guide rod being arranged with slight play relative to one another.

Abstract: The invention relates to a method and an apparatus for producing concrete blocks, in which concrete mortar (14) is moved across a mould (7) by means of a filling carriage (4) and the mould (7) is filled with concrete mortar (14) from the filling carriage (4), whereupon the filling carriage (4) is returned and the concrete mortar (14) located in the mould (7) is compacted first of all by means of a plunger (13), movable from above in the direction of the mould (7), and then by vibration, the plunger (13) being moved via two synchronized motors (15) located one behind the other in the direction of travel of the filling carriage (4) and the torques exerted by said motors (15) being measured, the filling operation of the mould (7) being corrected in accordance with the deviation of actual values, derived from the difference in the measured torques, from predetermined desired values.

Abstract: The invention relates to a concrete-block-making machine having a part which is displaceable via a linear drive, the linear drive comprising a drive unit and a linear guide for guide rollers, the drive unit comprising at least one linear motor and the linear guide comprising at least one guide rod for the guide rollers, the at least one guide rod and the guide rollers movable relative thereto being hardened, and guide rollers and guide rod being arranged with slight play relative to one another.

Abstract: 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.