Since the 1960s, lock manufacturers have been patenting keys and locking mechanisms for the purpose of preventing unauthorized key duplication. Patented keys improve the life expectancy of a key system by reducing the threat of being compromised. Patents restrict key blank purchasing and manufacturing from anyone who is not authorized. There has also been strong support by the manufacturers to bring legal action against companies and individuals that try to get around their patent protection. To maintain patent protection, new patents have to be acquired as utility and design patents have a limited timeframe of approximately 17 years.
Schlage “C” Keyway
In the mid-1930s Schlage introduced the "C" keyway pin tumbler lock cylinder and key blank. For more than seven decades, this lock cylinder has been the default for just about every Schlage pin tumbler lock. Because of the level of customer acceptance, most commercial and many residential lock manufacturers either have the "C" keyway as their default keyway or at a minimum offer a "C" keyway as an option for their locks. Even today, more than 10 years since the "C" key is no longer Schlage's default, it is still available from just about every lock manufacturer, locksmith, key cutter, etc.
In the early 2000s, Schlage Lock changed from the "C" six pin tumbler lock cylinders (Classic) to the patent protected Everest "C123" lock cylinders as the default for their commercial locks and master key systems. The Everest lock cylinder has a check pin located between the fifth and sixth pin chambers on the right side of the keyway. This check pin has to be lifted by a properly bitted operating key in order for the plug to be rotated. Everest lock cylinders and key blanks are available as open and restricted keyways. The Everest full sized lock cylinders are compatible with Schlage mechanical and electronic locks including the A, AD, AL, B, CO, D, H, L, ND, NDE and S.
The "C123" is one of more than 10 "C" open keyways. The United States Utility patents 5,715,717 and 5,809,816 protected against unauthorized manufacture and distribution through July 20, 2014. To identify the Everest keys, Schlage changed the bow shape from the "C" key to a more rounded head. In addition, Everest keys and locks have the Everest logo incised into the shank and the plug face. Everest key blanks have a lifetime guarantee against breakage.
Everest "C123" and other Everest "C" keyway lock cylinders have a higher security lock mechanism. Schlage Everest lock cylinders use standard Schlage top, bottom and master pin tumblers. The patented undercut groove is milled into the right side of the key blade to operate the check pin. When the proper bitted Everest key is inserted into the Everest lock cylinder, the lip of the under cut groove lifts the check pin in the lock cylinder permitting the plug to be rotated. Requiring an undercut lip to operate the check pin prevents standard keys from operating the lock cylinder. All Everest key blanks have a portion of the undercut lip removed to prevent the key from being modified to operate a Primus lock cylinder.
Unlike a number of high security keyways, the Everest "C123" and other patented keyways are available to locksmiths for key duplication and lock servicing without completing any official procedures. The "C123" keyway is considered "open," which means it can be stocked and sold by all locksmiths purchasing them through locksmith distribution channels and contract hardware channels. According to Schlage, they are not available at home centers.
To simplify the conversion from the "C" keyway to the Everest "C123" keyway, Schlage constructed the "C123" key profile to be backwards compatible with "C" keyway. This way, new Everest lock cylinders can be incorporated into existing systems by incorporating "C123" keys, without having to initially replace all of the lock cylinders.
Everest 29 Patent 7,665,337 provides protection until 2029. The Everest 29 full size open keyway family is the "S". In January 2013, the Everest 29 S123 became the default keyway for Schlage commercial locks. The Everest 29 S145 will be the default keyway for new master key systems unless another keyway is specified. The Everest 29 is available as open and restricted keyways.
The Everest "S123" key is backwards compatible to the Everest "C123" keyway lock cylinders. However, the "S123" key is not backwards compatible with the "C" keyway lock cylinders. All Schlage Everest 29 full sized lock cylinders are equipped with the check pin. To combinate the lock cylinders, use standard Schlage top, bottom and master pin tumblers.
Everest 29 keys have a larger, more rounded bow to easily distinguish between this key and the Everest key. In addition, a hole in the shank accommodates the through-cut technology, which is used to more efficiently create the undercut in the blade. Like the Everest, a portion of the Everest 29 key blade lip has been removed to prevent the key from being modified to operate a Primus lock cylinder. Everest 29 key blanks have a lifetime guarantee against breakage.
Everest "S" Family "open" keyways are available to end users from locksmiths for key duplication without any official procedures. They can be stocked and sold by all locksmiths. According to Schlage, they are not available at home centers.
Everest Primus XP & Everest 29 Primus XP
To increase the level of Schlage key control including geographic exclusivity, there are options for the Everest and Everest 29. They are the Everest Primus XP and Everest 29 Primus XP lock cylinders, which are restricted. Like the Everest and Everest 29 lock cylinders, they are backwards compatible. Everest Primus XP and Everest 29 Primus XP equipped lock cylinders eliminate the check pin, instead incorporating the Primus patented five finger pin and sidebar design. In addition to the conventional six pin tumbler lock mechanism, this provides a high level of pick resistance. They are available with UL437 drill resistance.
Everest Primus XP lock cylinders and keys are patented until 2024. Everest 29 Primus XP lock cylinders and keys are patented until 2029.