Abstract: A vibration generator includes a weight member, a shaft rotatable about an axis of rotation extending longitudinally therethrough and having a mounting area on which the weight member is mounted, and a positioning arm disposed in engagement with the weight member on the shaft and rotatable about the axis of rotation relative to both the shaft and the weight member. The mounting area engages the weight member and prevents movement of the weight member relative to the shaft in a circumferential direction about the axis of rotation but permits movement of the weight member relative to the shaft in a radial direction orthogonal to the axis of rotation and coplanar with the circumferential direction. The weight member also defines an elongate positioning slot and the positioning arm includes an axially extending portion disposed through the positioning slot for slidable movement within the positioning slot during rotation of the positioning member relative to the shaft.

Abstract: A powered mechanism is described for controlling the dumping of mortar from a tilting mortar mixing drum. The powered mechanism is highly mechanically advantaged, so that a single operator has precise control of the dumping procedure. A mortar mixing drum has a rotatable paddle shaft and at least one paddle attached to it. The mortar mixing drum is operative between a home, mixing position, and a mortar dumping position. A drive mechanism is connected to the rotatable paddle shaft for rotatively driving the shaft and the paddle attached to it. A transmission mechanism has a ring gear attached to the mortar mixing drum and a pinion gear in rotative contact with the ring gear. The transmission mechanism also has a drive belt and a drive pulley rotatively attached to the rotatable paddle shaft. A hand-operated lever is engageable with the drive belt of the transmission mechanism to engage the drive belt for driving the transmission pulley, which causes tilting of the mixing drum.