Tubular Keys - Arcadia KeylineChicago, 1920s.

The home of gangsters, Prohibition and jazz music, but not only this. Here, on the northern side of the city, a lighting rod factory takes its first steps and launches itself resourcefully forward by starting to build furniture and then locks for closets, chests and the like, findings its own core business.


It’s the beginning of the Chicago Lock Co., which became known for the invention of the tubular keys, marketed with the Ace brand since 1933. The innovation rapidly spread to the furniture and military field, and then, little by little, to the automatic distribution, to the anti-theft systems, to the strongboxes and, finally to the laptop computers.



The Ace System


This system employs a cylinder key, with a larger diameter than most conventional keys, which falls into the first pin’s hole. It is equipped only with one tooth to hook up the lock coil lid and a series of grooves aligned at the inlet guide tracks.


Within the lock, the guide tracks support six or eight double pistons, arranged around the movable round coil lid, as in the Yale system, but in an horizontal way. Here too the springs push the pistons forward to lock the coil lid in a closed position.


When the key is inserted, the pistons are moved backwards by the corresponding grooves engraved on the key, until the line between the piston on the front and the one on the back is aligned to the separation margin between the cylinder and the coil lid, thus allowing its rotation.


A “Safe” Success


The success of the tubular locks, or tubular pin tumbler locks, to be more precise, is mainly due to the complexity of cutting this kind of key, which, therefore, makes it very safe. In 2012, Keyline has launched Arcadia, a special key cutting machine for this unique and widespread type of key, with an extensive set of adapters and important innovations as the electronic control of the cutter, the protective screen and the LED light.