time lock

a lock, as for the door of a bank vault, equipped with a mechanism that makes it impossible to operate the lock within certain hours.

Origin of time lock

First recorded in 1865–70

He hummed an air, and strolled out into the main corridor to stare at the curious dial of the time-lock.

Hugo |Arnold Bennett
It fastened with three solid steel bolts thrown simultaneously with a single handle, and had a time-lock.

Roads of Destiny |O. Henry
And money has been taken from it despite the time-lock precautions.

The Riddle of the Mysterious Light |Mary E. Hanshew
Unfortunately for them the safe is of the latest London pattern with a time-lock, which I bought when in England last year.

Captain Macedoine's Daughter |William McFee

In the same year, 1847, the time-lock was invented by Savage.

Invention |Bradley A. Fiske