How to Make Concrete Blocks

Learn how Hi Sibley produces 100 concrete blocks per hour as he describes the concrete block manufacturing process.

| May/June 1977


Next, crane is attached to mold and the ejector swung into position. Holding the ejector down, operator depresses a pedal, lifting the mold. Then after moving the blocks, the process is repeated.


That's right! 100 blocks per hour ... provided you have the help and the space and racks to cure the blocks properly. In Figure 1 (in the Image Gallery) you see the outfit complete, ready for work. It's a self-contained unit mounted on its own two-wheeled, pneumatictired trailer with a supporting caster wheel under the drawbar. There's nothing to take apart and put together again when you move the machine. Merely disconnect the water hose and the power line, hitch it to a truck, and away you go.

Figures 4 through 7 (in the Image Gallery) show how it works. Figure 2 details the metal mold and Figure 3 the ejector plates and assembly. In Figure 4 the mold, supported by a crane, is being lowered into place on the molding "board," in this case a steel plate somewhat larger than the mold. In Figure 5 the mix is being scraped and troweled into the mold. When full, the mold is vibrated by means of a footoperated take-off drive, and then the excess material is struck off the top with the fence or striker board. Next, the crane is hooked to the mold and the ejector is swung into place. In Figure 6 the operator bears down on the ejector and simultaneously presses a foot pedal to raise the mold off the formed blocks. In Figure 7 the finished blocks are being moved to the curing racks.

Figure 8 shows the main frame, entirely a welded job using 3- and 4-inch pipe, steel plate, and steel channel. Only general dimensions are given as some of these parts must be sized to fit during the assembly of other parts of the machine. With the exception of the motor, which is only a representation, the crosshatched views in Fig. 9 are intended to give a general guide to proportionate sizes of the machine parts and their relative positions. To make the manner of assembly more clear, certain parts have been omitted from these details. No detailed dimensions have been given in Fig. 9 because these will vary somewhat according to the materials and parts which you have or which are available.

Figures 10 to 15 inclusive show the assembly. From these details you will see first that the main drive from the motor to the mixing chamber is made from a Ford Model-A rear axle and drive shaft, (Figure 11). One axle housing is removed and the open end of the differential housing is covered with a sheet-metal disk bolted on with a gasket between to prevent leakage of lubricant. A roller-chain drive sprocket is welded or keyed to the axle and a two-step V-pulley is attached to the drive shaft. The drive thus formed from this unit is welded to the trailer frame at three points: at the end of the Model-A axle housing where it passes through a hole in the mixing-drum bracket, and at the differential and the forward end of the drive-shaft housing, where it also is supported on brackets.

The hopper, Figure 10, and the mixing drum are made of heavy sheet metal welded at all joints and reinforced with steel angles welded on as stiffeners wherever large areas of the metal are subjected to severe strain. The steel mixing blades of the agitator, Figure 9, the top view, have a clearance of about 3 inches inside the drum.

Figures 13 and 14 and the two upper views in Figures 11 detail the crane and ejector arm. The crane is an allwelded assembly of standard rod and pipe sizes and is operated by a pedal which extends underneath the machine. However, the ejector mechanism is a somewhat more intricate affair. The ejector plates must raise and lower in the same plane, making two pairs of adjustable parallel arms necessary. A "helper" spring eases the lift of the assembly and another coil spring swings it to one side. Bearings at both ends of the four arms should fit accurately. Figure 11 shows the frame which supports the crane and ejector.

imma asensio esplugas
3/7/2013 8:53:07 AM

I think that the best concrete block machines in the world are manufactured by the company Prensoland in Spain. They are capable to produce very high outputs and almost no need of maintanance.

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