US Patent 7140209 Padlock with fully integrated dual locking systems

By providing two separate and independent locking systems formed in a single padlock, with both locking systems independently enabling the single shackle to be released and/or lockingly engaged, an effective, easily produced, multi-purpose padlock is achieved. In the preferred embodiment, a single housing and shackle assembly are employed and constructed for enabling the shackle to be released from locked engagement with the housing using either a rotatable dial combination construction or a key activating tumbler construction. In this way, a dual locking and releasing padlock is achieved which virtually eliminates the difficulties typically encountered with known, prior art lock configurations.