Ring lock with relocking

A ring lock, comprising:

• a housing;
• a shackle movable relative to the housing between an open position and a closed position;
• a lock cylinder operable to maintain the shackle in the closed position, and selectively operable to permit movement of the shackle from the closed position to the open position;
• and
• a first frangible component, wherein the first frangible component is configured to break in response to application of a first threshold torque to the lock cylinder;
• wherein the lock cylinder is configured to move in a direction transverse to a rotational axis of the lock cylinder to a displaced position in response to breaking of the first frangible component;
• and
• wherein, with the first frangible component broken and the lock cylinder in the displaced position, the lock cylinder is prevented from permitting movement of the shackle from the closed position to the open position.

A method of operating a portable lock apparatus comprising a lock cylinder, a shackle, and a first frangible component, the method comprising:

• receiving insertion of a key in the lock cylinder;
• in response to rotation of the key to an unlocking orientation, permitting movement of the shackle between an open position and a closed position;
• with the shackle in the closed position, receiving insertion of a tampering tool to the lock cylinder;
• in response to application of a first threshold torque to the lock cylinder via the tampering tool, breaking the first frangible component;
• and
• preventing movement of the shackle from the closed position as a result of breaking the first frangible component, the preventing comprising shifting the lock cylinder in a direction transverse to a rotational axis of the lock cylinder from a home position to a displaced position in response to breaking of the first frangible component.