shortlineflyer wrote:Hey everyone,
I was wondering how the mechanism that keeps ic cores held in work. could someone give me some info about this. I understand that it involves a special key but what does that mean. I know one key opens the lock and the other removes the lock.
@shortlineflyer:
Expanding on the excellent answer provided by chriswingate, how it works all depends on the manufacturer and age/style of the specific IC cylinder and housing you are considering:
Method #1: With some IC's the core retention device is activated indirectly by means of a special longer keyblank which interacts with some mechanism at the back of the core where operating keys can not reach it during normal use to allow for removal of the core from the housing... So any valid operating key cut onto the control blank will function as a control key -- this is usually the Top Master Key when considering a cylinder with more than one key that operates... So the only functional difference is the special control blank...
-- This method applies to LFIC's made by: Yale, Lockwood (U.S.), Schlage and some very early old original Medeco...
Method #2: With Best/Falcon/Arrow/etc. SFIC's there is an additional complete sleeve around the cylinder plug called the control sleeve... It operates the control lug which is an integral part of the sleeve at a totally separate and unique shearline which is distinct from the operating keys which are keyed into the plug shearline... The control keys in this type of arrangement are cut on the same blanks as the operating keys, using a unique bitting which is reserved for the control key function...
-- This method only applies to SFIC's...
Method #3: With other LFIC's the core retention activated directly by means of a special partial sleeve which is installed in certain pin chambers of the IC cylinder... The location of these special chambers and the number of pin chambers included as part of the partial sleeve varies by manufacturer and age of the IC core in question... The control key is required to have several identical cuts to the Top Master Key in a master keying system OR the operating key in a single keyed core -- often being cut differently from the operating key(s) in only 1 or 2 chambers to accomplish the control function...
In many older style IC's there was a dedicated pattern of interrelationship which must be followed in the cuts in the control sleeve chambers and control/master/change keys had to be different by certain depths...
With newer style Medeco IC's the control function is accomplished by cutting the control key to a specified depth depending on what depth of the change key is in that same chamber, adding a master pin only if a master key also should operate...
-- This method applies to special cylinders(old)/LFIC's made by: Corbin (old), Russwin (old), Corbin-Russwin, Medeco and Sargent...
Did you have any other questions about how these cylinders operate besides how to pick them to the control function to remove them from their housing without possessing the control key for the core?
The only cores which can reliably be picked to the control function with a special tension tool are SFIC's...
~~ Evan