Abstract: A mold frame for an apparatus for producing shaped concrete articles has two longitudinal and two transverse frame members which are detachably screwed to one another with form-fit on the four corners of the rectangular mold frame. The transverse frame members on their end faces have polygonal pins which fit closely into the correspondingly shaped recesses of the longitudinal frame members to resist torsional movement. The polygonal pins and recesses are penetrated by one locking screw at a time with which the mold frame is braced in itself. A mold insert which has several mold cavities is braced within the mold frame by a tongue and groove connection. The form-fit screw connection between the longitudinal and transferse frame members makes it possible to accommodate the very high forces and torques which are formed by shaking vibrations during the molding process.

Abstract: The side walls of a mold have recesses in each of which is mounted a mold core for forming depressions on the outer side of a concrete block which is to be produced in this mold. The mold cores are pivotally supported around a horizontal axis which is parallel to the mold walls on the outer side of the mold. A sloping cam slot on each mold core is used to pivot the mold cores into the mold cavity defined by the mold walls and then back into the recess. The inner edges of a recess closely fit the mold core and function as strippers which self-clean all surfaces of the mold core which have come into contact with the concrete when the mold core is pivoted back into its recess. As a result, time intervals for cleaning the mold cores are greatly lengthened and a clean and smooth surface of the finished concrete block is insured.

Abstract: A mold frame for an apparatus for producing shaped concrete articles has two longitudinal and two transverse frame members which are detachably screwed to one another with form-fit on the four corners of the rectangular mold frame. The transverse frame members on their end faces have polygonal pins which fit closely into the correspondingly shaped recesses of the longitudinal frame members to resist torsional movement. The polygonal pins and recesses are penetrated by one locking screw at a time with which the mold frame is braced in itself. A mold insert which has several mold cavities is braced within the mold frame by a tongue and groove connection. The form-fit screw connection between the longitudinal and transferse frame members makes it possible to accommodate the very high forces and torques which are formed by shaking vibrations during the molding process.

Abstract: A vibration drive particularly suited for a mold for producing concrete molded bodies comprises of at least one piezoelectric vibration exciter which is fixedly attached onto the mold. The vibration exciter comprises a housing in which an unbalance mass is movably supported and is drivingly connected to a piezoelement which is also located in the housing to produce vibration. When an AC voltage is applied to the vibration exciter a deformation movement occurs which is converted into an oscillating motion of the unbalance mass and which thus produces vibrations of the mold.

Abstract: The vibration drive for a mold for producing concrete mold bodies has four piezoelectric vibration exciters which are located in the four corner areas of a vibrating table of a molding machine and connected to the machine frame. A vertically movable mold with several mold cavities which are open to the top and bottom is deposited on the vibrating table. After filling the mold cavities with concrete, the vibration exciters are activated and are caused to vibrate by shaking, these vibrations being transferred to the vibrating table and the mold. The vibration exciters are electrically connected to a microprocessor which controls the vibration frequency and other parameters of the vibration drive by corresponding, preselectable computer programs.

Abstract: A mold, for the production of concrete shaped bricks having one or more inclined side walls, has an inclined side wall which together with the opposed vertical mold side wall diverges upwardly to form an angle that is opened upwardly, the inclined side wall is moved upwardly in the direction of inclination in order to open the mold and to enable the shaped bricks to be removed from the mold. The movement of the inclined side wall along the inclined space of the shaped brick during removal of the mold results in a smooth clean even surface.