Invention of the wheel has been called one of the great steps in the development of technology. And inventors today are still finding new uses for it. One is in the concrete imprinting business. Made in three approximately 30-pound sections to be locked together to form a circle, the cylinder-like tool is made of hard rubber plastic with embedded steel reinforcing. The assembled cylinder is of a diameter that allows it to be propelled by workmen who step inside it and walk forward at an even pace.

The imprinting procedure begins after the concrete has been placed, colored and troweled to the desired finish. The cylinder is rolled into place at the edge of the slab, aligned with it by sighting along the edge of the form or a snapped string line, then rolled onto the slab. The required number of persons then enter it and position themselves in each of the cylinder sections so that the tool can be walked across the slab.

Large concrete slabs seldom have the same consistency throughout some areas may be softer or harder than others. Where this condition occurs, a series of ganged cylinders will tend to bridge over the softer areas so all grooves are imprinted to the same depth. Because of the speed with which imprinting is done by this method, an entire slab can be completed within the optimum imprinting time.