Abstract: Apparatus and method for carrying out compaction operations on molded bodies that consist of granular materials and are placed on pallets, the compaction being achieved by impact of a vibrating table on the underside of the pallet. The vibrating table, together with a spring system forms a mass-spring system, which acts as a vibrator capable of oscillation that is excited by an excitation device to produce forced vibrations. The spring system, together with the system mass, is designed to develop at least one individual frequency within the range of the compaction frequency, whereby it is also possible to adjust the individual frequency gradually or continuously. This, together with the fact that the excitation frequency can be adjusted, allows the vibrator to be operated partially or completely in resonance mode over the whole frequency range of the compaction.

Abstract: The invention relates to a regulating device for an unbalanced mass vibration generator, comprising at least two pairs of partial unbalanced mass bodies that can be driven around an allocated axis whose vectorially added partial centrifugal force vectors form the resulting centrifugal force vector. Adjustment is carried out between a resulting minimal unbalance moment (amplitude of oscillation=minimal) and a resulting maximal unbalance moment (amplitude of oscillation=maximal) without any intermediate positions, whereby both allocated limiting phase angles are regulated using two stops. The regulating device also enables acceleration and stopping of the vibrator with a regulated minimal unbalance moment. The regulating device selectively utilizes one or two drive motors for regulating the phase angle. Due to the utilization of stops in adjusting the phase angle, it is no longer necessary to use complicated control means and a compact structure is made possible.

Abstract: An adjusting device for an unbalance vibrator with adjustable centrifugal moment. The invention concerns specifically the specialised category of vibrators in which each unbalance shaft has its own motor (110, 112, 114, 116) and no transmission system is provided for connecting the minimum of four unbalance shafts. A novel way of hydraulically actuating the motors is described for ram vibrators of this type provided with four hydraulic motors (110, 112, 114, 116). This involves connecting two motors (the ones allocated to the two unbalance shafts which always rotate synchronously counter to one another even during adjustment) in parallel to their own respective hydraulic circuits. Each of the two hydraulic circuits (118, 120) has its own pump (P1, P2) and the pressures in the forward flow and/or back flow lines can be adjusted independently from the outside by a control and regulation device (126, 128) in such a way that they can be used to set the centifugal moment in a predeternmined manner.

Abstract: An unbalanced-mass vibrator comprises a pair of unbalanced masses which are sequentially driven in opposite rotational directions. The vibrators are intended to provide vibrations in a vibrational direction, and undesired vibrations transverse to the vibrational direction are reduced or eliminated. In particular, mechanisms in control schemes are provided for adjusting the relative torques delivered to each of the unbalanced masses via hydraulic motors. The torques, in turn, may be controlled based on the degree to which the unbalanced masses are out of synchronization or by measurically measuring vibrations in a transverse direction to the desired vibrational direction, or time derivative thereof.