ALEXANDRIA, Va., April 21 -- United States Patent no. 12,607,273, issued on April 21, was assigned to ASAHI YUKIZAI Corp. (Nobeoka, Japan).
"Suck-back valve" was invented by Yusuke Kumatabara (Nobeoka, Japan) and Kenro Yoshino (Nobeoka, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "A suck-back valve includes a valve main body formed with a suck-back chamber, and a suck-back mechanism unit. The suck-back mechanism unit includes a suck-back piston accommodated in a suck-back cylinder chamber and being slidable between two dead center positions, and a biasing member biasing the suck-back piston in a direction to increase the volume of the suck-back chamber. The suck-back cylinder chamber is divided by th...