The Bramah Mechanism
In 1787 Joseph Bramah’s lock patent was granted with 479,001,600 keys required to open it under all its variations. Since then, numerous releases, of the key mechanism have followed. Since 1963 the current mechanism has had 524,288 differs under all its variations, with the next release planned at 2,097,152 differs.
The Bramah mechanism is sold as both a traditional English Mortice lock as well as in Cylinder format capable of insertion into a wide variety of lock cases for differing applications.