Method of manufacturing a concrete plank

Claim 1

A METHOD OF MANUFACTURING CONCRETE PLANKS HAVING INTERNAL REINFORCING STEEL, SUCH METHOD CONSISTING IN THE STEPS OF PREFABRICATING BLOCKS HAVING INTERNAL PASSAGES ADJACENT THEIR CORRESPONDING FACES TO RECEIVE SUCH STEEL, FACING THE ENDS OF THE BLOCKS WITH A GRINDER TO RENDER THEM FLAT AND SMOOTH, ALIGNING THE BLOCKS IN AN ELONGATED ROW WITH THE SAID PASSAGES IN REGISTRY, WITH THEIR FACE ENDS IN ABUTMENT, INTRODUCING STEEL INTO THE REGISTERING PASSAGES OF THE ALIGNED BLOCKS, MAKING PORTS AFFORDING ACCESS TO SAID PASSAGES AT INTERVALS THROUGHOUT THE LENGTH OF THE SERIES OF ALIGNED BLOCKS, CONNECTING THE SERIES OF ALIGNED BLOCKS TOGETHER UNDER PRESSURE EXERTED LONGITUDINALLY OF SAID SERIES ADVANCING THE ROW OF CONNECTED ALIGNED BLOCKS IN A DIRECTION LONGITUDINALLY OF THE ROW PAST A GROUTING STATION, AND INTRODUCING GROUT UNDER PRESSURE AT SAID STATION THROUGH EACH PORT INTO THE PASSAGES ABOUT THE STEEL THEREIN, WHEREBY GROUT IS INTRODUCED AT A PLURALITY OF POINTS IN SAID ROW OF CONNECTED BLOCKS, AND MAINTAINING THE BLOCKS OF SAID ROW UNDER SAID PRESSURE UNTIL THE GROUT HAS SET.