Abstract: A pallet cleaning device used to clean pallets moved from a pallet magazine or supply hopper to the molding section of a concrete block molding machine includes a frame for mounting the pallet cleaning device directly in front of the pallet magazine of the block making machine. A first sub-frame is pivotally mounted on the main frame and is biased by gravity against a stop located on the main frame to establish the position of a set of four pallet scraper blades mounted side by side across the path of a pallet passing beneath the device. A blade holder is pivotally mounted on the sub-frame to locate the scraper blades at an angle; so that they contact the pallet on a line located behind the vertical projection of the pivot mounting of the blade holder on the sub-frame in the direction of travel of a pallet for cleaning. Resilient springs are used to bias the scraper blade holder against a stop engaging the sub-frame to locate the scraper blades.

Abstract: A variable mechanical vibrator includes a first eccentric weight fixed to a rotatably mounted shaft. A second eccentric weight is rotatably mounted on the shaft, and the two weights are rotated together under control of mating engagement abutments, one carried by the shaft and one carried by or comprising a surface of the second eccentric weight. In one embodiment, first and second prime movers are used to rotate the shaft and the second eccentric weight, respectively; and when primary rotation of the shaft is effected by the first prime mover, the first and second eccentric weights are diametrically oppositely aligned with respect to one another on the shaft providing a balanced operation. In this mode of operation, the abutment carried by the shaft drives the abutment on the second weight to rotate such weight set with the shaft.

Abstract: A concrete block molding machine has the pallet support table mounted on the main frame of the machine through pneumatic tires which provide vibration isolation between the pallet support table and the main machine frame. A mold, having vibrating mechanism mounted on it is lowered into position on pallets supported by the pallet support table, and the mold and pallet support table are clamped together on opposite sides of a pallet during the molding operation. A plunger head is carried on the main machine frame through additional air bag vibration isolators to engage materials in the mold to compact them during the molding operation while the vibrators are operating. Upon completion of the molding operation, the table and mold are unclamped to permit a stripping plate to move the mold upwardly off of the pallet; so that the pallet and the green concrete blocks may be moved out of the machine and a new pallet may be positioned for the next cycle of operation.