Five-Pin "advances" circa 1979

[GWiens2001]

For clarity sake, adding that the grooves only in the cutaway lock pictured in Squelchtone's picture are colored. They are not colored in just any Medeco lock you pick up.

Gordon

[Bricago]

Squelchtone, thank you for the video and explanation. That is exactly what the Time Life piece was describing. Forgive a basic question, but what keeps the key pins from resting on the floor of the keyway? I've noticed that in cutaway pics and illustrations the key pins are in contact with the driver pins, but unsupported from the bottom and seem to "hover" between the plug and shell.

[GWiens2001]

Squelchtone, thank you for the video and explanation. That is exactly what the Time Life piece was describing. Forgive a basic question, but what keeps the key pins from resting on the floor of the keyway? I've noticed that in cutaway pics and illustrations the key pins are in contact with the driver pins, but unsupported from the bottom and seem to "hover" between the plug and shell.

The pin channels that the pins ride in only go part way into the core of the lock, so the pins only go that far down.

Gordon

[Bricago]

The pin channels that the pins ride in only go part way into the core of the lock, so the pins only go that far down.

Thank you, Gordon. I think I get it now.

[Bricago]

In favor of Keso, I am not sure when The Complete Guide to Locks and Locksmithing started covering high security locks, but Medeco and Keso were in the high security lock section and the Time-Life researches probably consulted that book as it was the locksmithing book in libraries.

You nailed it, JM. Here's a quote from chapter one in The Complete Guide...Sixth Edition which also features the Medeco on the cover: “A recent innovation in high-security mechanical locks came in 1967, with the introduction of the Medeco high-security cylinder. The cylinder, made by Roy C. Spain and his team, used chisel-pointed rotating pins and restricted angularly bitted keys that made picking and impressing harder. To open the lock, a key had to not only simultaneously lift each pin to the proper height, but also rotate each one to the proper position to allow a sidebar to retract. The name “Medeco” was based on the first two letters of each word of the name Mechanical Development Company.”