Stressed plastic valve for laboratory glassware

Claim 1

A VALVE COMPRISING A LENGTH OF GLASS TUBING OPEN AT ITS ENDS AND FORMING A ROTARY PLUG BARREL HAVING OPEN ENDS, SAID BARREL HAVING A STRAIGHT CYLINDRICAL BORE OF SUBSTANTIALLY CONSTANT DIAMETER EXTENDING THERETHROUGH FROM END TO END, PLURAL GLASS TUBULAR MEANS JOINED TO SAID BARREL AND OPENING THEREINTO, A CYLINDRICAL THEREMOPLASTIC PLUG OF SUBSTANTIALLY CONSTANT OVERALL DIAMETER FITTING IN SAID BORE FOR ROTATION THEREIN, MEANS CARRIED BY SAID PLUG FACILITATING AXIAL ROTATION THEREOF IN THE BORE, FLOW PASSAGE FORMING MEANS IN SAID PLUG AND POSITIONED FOR ESTABLISHING COMMUNICATION BETWEEN SAID PLURAL TUBULAR MEANS UPON ROTATION OF THE PLUG TO ONE POSITION, SAID PLUG BEING FORMED IN A PORTION THEREOF BETWEEN EACH END THEREOF AND SAID FLOW PASSAGE WITH A MULTIPLICITY OF MINUTE ENCIRCLING CLOSELY SPACED RIBS OVERSIZE AT LEAST APPROXIMATELY 10/1000 OF AN INCH WITH RESPECT TO THE DIAMETER OF SAID BORE AND HIGHLY COMPRESSED IN THE BORE TO MAINTAIN A LEAKPROOF ENGAGEMENT AGAINST THE SURFACE OF THE WALL OF THE BORE, SAID PLUG HAVING AXIALLY EXTENDING CHAMBERS THEREIN SPACED APART AND SEPARATED INTERMEDIATE THEIR ENDS BY A SOLID PORTION OF THE BODY OF THE PLUG THROUGH WHICH SAID FLOW PASSAGE FORMING MEANS EXTENDS, AND SAID CHAMBERS OPENING AT THE OPPOSITE ENDS THEREOF THROUGH THE ADJACENT ENDS OF THE PLUG AND THROUGH THE OPEN ENDS OF THE BARREL.