Apparatus for casting hollow reinforced and pre-stressed members

Claim 1

IN APPARATUS FOR CASTING HOLLOW CONCRETE MEMBERS, IN COMBINATION, A CASTING BED; A LOWER OPEN TOP FORM MOUNTED IN FIXED POSITION ON AND ALONG SAID CASTING BED; AN OUTER SLIP FORM MOVABLY MOUNTED ON SAID CASTING BED OVER SAID LOWER FORM FOR MOVEMENT IN ONE DIRECTION THEREOVER AND THEREALONG DURING A CASTING RUN; AN INNER SLIP FORM MOVABLY MOUNTED AND MAINTAINED IN POSITION EXTENDING THROUGH SAID OUTER SLIP FORM BETWEEN AND SPACED FROM SAID LOWER FORM AND SAID OUTER SLIP FORM; THE LENGTH OF SAID INNER SLIP FORM BEING IN DIRECT RELATION TO THE RATE OF SPEED OF DISPLACEMENT OF THE OUTER SLIP FORM AND THE INNER SLIP FORM ALONG THE CASTING BED DURING A CASTING RUN, TO THE PLASTICITY OF THE CONCRETE AND THE RATE OF SET OF THE CONCRETE; MEANS FOR SIMULTANEOUSLY MOVING SAID OUTER SLIP FORM AND SAID INNER SLIP FROM ON SAID CASTING BED OVER AND ALONG SAID LOWER FROM THROUGH A CASTING RUN; AND HOPPER MEANS MOUNTED ON SAID OUTER SLIP FORM AT THE LEADING END THEREOF FOR CONTINUOUSLY POURING CONCRETE MIX INTO SAID LOWER FORM AROUND SAID INNER FORM AND BETWEEN SAID LOWER FORM AND SAID OUTER FORM AS SAID INNER AND OUTER SLIP FORMS ARE SIMULTANEOUSLY MOVED ALONG SAID CASTING BED DURING A CASTING RUN; A FRAME STRUCTURE PIVOTALLY CON-