摘要 |
A plunger type lock comprising a barrel with an axial bore, locking members in the form of balls housed in the barrel wall and extensible outwardly from the barrel by a plunger axially slidable within the barrel bore, at least one further ball housed in an opening in the wall of the plunger and extensible outwardly therefrom and a peripheral groove on the inner wall surface of the barrel for receiving the further ball, the further ball being forceably moved and held in the barrel's groove by an incorrect key, instrument or an implement to prevent and resist movement of the plunger whenever an unauthorized attempt to operate and open the lock is made.
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