How did James Sargent’s time lock limit when a safe could be opened?

In the 1870s, a criminal trend emerged in the United States where robbers would force bank cashiers to surrender keys or combinations to vaults. To address this security threat, James Sargent of Rochester, New York, developed a specialized lock in 1873.

His design incorporated a clock mechanism that prevented the safe from being opened until a specific, preset time had been reached. By tying the lock's operation to a timer, Sargent ensured that the safe remained inaccessible outside of designated hours, effectively neutralizing the ability of criminals to force employees to open vaults under duress.1