Patent ID: 7290540

Claim:
A practicing apparatus, comprising: a housing; a first feeding member mounted on an end of the housing and having a first entrance; a second feeding member detachably mounted in the first feeding member and having a second entrance having a diameter smaller than that of the first entrance of the first feeding member; and a locking device mounted on the first feeding member and detachably engaged with the second feeding member to lock the second feeding member in the first feeding member; wherein the second feeding member has a periphery formed with a locking hole, and the locking device includes a locking shaft retractably mounted on the first feeding member and detachably locked in the locking hole of the second feeding member to lock the second feeding member in the first feeding member; the locking device further includes a housing secured on a periphery of the first feeding member, and a sleeve mounted in the housing, and the locking shaft is movably mounted in the sleeve and has a lower end protruded outward from a lower end of the housing and detachably locked in the locking hole of the second feeding member; the locking device further includes an elastic member mounted on the locking shaft and biased between the locking shaft and the sleeve to push the locking shaft toward the locking hole of the second feeding member.