Pipe header for forming gasket grooves in concrete pipe tongues

Claim 1

. IN A GROOVE FORMING APPARATUS FOR CONCRETE PIPE TONGUES, THE COMBINATION OF A BASE RRING AND A TOP RING ADAPTED TO ENCIRCLE A PIPE TONGUE, A LEFT-HAND PAIR AND A RIGHT-HAND PAIR OF POSTS CONNECTING SAID BASE RING AND SAID TOP RING TOGETHER IN SPACED RELATION WHEREBY TO PROVIDE AN ANNULAR SPACE BETWEEN SAID RINGS, A SECTIONAL GROOVE FORMING COMPONENT DISPOSED BETWEEN SAID RINGS AND COMPRISING A LEFT-HAND PAIR AND A RIGHT-HAND PAIR OF QUADRANTS RADIALLY PROJECTIBLE AND RETRACTABLE THROUGH SAID ANNULAR SPACE BETWEEN THE RINGS, A LEFT-HAND PAIR AND A RIGHT-HAND PAIR OF CONTROL ARMS RIGIDLY CONNECTED TO THE RESPECTIVE QUADRANTS IN THE RESECTIVE PAIRS AND PIVOTALLY MOUNTED ON THE RESPECTIVE POSTS IN THE RESPECTIVE PAIRS, MEANS MOVABLY CONNECTING TOGETHER ADJACENT ENDS OF THE QUADRANTS IN EACH PAIR, AND FLUID OPERATED MEANS REACTING BETWEEN THE LEFT-HAND AND RIGHT-HAND PAIRS OF QAUADRANTS FOR PROJECTING AND REACTING THE SAME THROUGH SAID ANNULAR SPACE.