COMPOUND NEEDLE WITH LOCK MECHANISM

摘要

A compound needle in which an inner needle does not advance when a cap is advanced to lock the inner needle. A compound needle provided with an outer needle having a tubular base at the base end of the outer needle, and also with an inner needle inserted from the rear end of the tubular base and protruded from the tip of the outer needle. The compound needle has a lock member having an insertion section located forward of a flange section formed on the outer peripheral surface of an axially intermediate section, a tapered surface provided at the rear end of the lock member and having an outer diameter reduced toward the rear of the lock member, and a slit formed by axially cutting a tube wall of the lock member. The insertion section of the lock member is inserted into the tubular base from behind. When a cap is rotated and advanced toward the front end thereof, the tapered surface of the lock member enters a tapered recess in the cap to reduce the diameter of an insertion hole where the tapered surface is formed. This tightens the inserted inner needle to set the inner needle to a locked state. Because the flange section is in contact with the rear end surface of the tubular base to prevent the lock member from advancing, the inner needle does not unintentionally advance.