Locks were created for the sole purpose of keeping people out while protecting the content within. Over the last 100 or so years, lock manufacturers improved the quality of mechanical locks, while developing different lock functions to provide the end user with features to make their lives more convenient. Some of these functions are entrance, storeroom, communicating and classroom.
Over the last 20 years or so, mechanical lock manufacturers have been providing higher levels of security for cylindrical and mortise locks. The categories Intruder and Security Locks have gained market share as they offer the ability to lock the outside lever or knob from the inside.
Lock manufacturers including Cal-Royal, Corbin Russwin, Marks USA, Sargent Lock and Schlage Lock Company are producing “security” locks for entrances and classrooms. They offer mortise and/or cylindrical lock functions that permit the key in the inside lever to control the outside lever providing the capability of locking down the lock from the inside. A sampling of the choices include:
- Marks USA’s Classroom Intruder cylindrical lock has the capability for deadlocking latch by lever from either side, except when the outside locked by key inside. Key outside locks or unlocks outside. Inside always open.
- Sargent T Zone 38 Classroom Security cylindrical locks feature the ability to lock the outside lever by key operating the inside lock cylinder. Only the key to the outside lock cylinder can retract the latchbolt when the outside lever is locked. Only the inside lock cylinder can unlock the outside lever for keyless operation. Inside lever is always free for immediate egress.
- The Corbin Russwin ML2052 Classroom Intruder Mortise Lock latchbolt operates by grip from either side; unless outside grip is locked by key either side. The latchbolt can be retracted by key when outside grip is locked. The auxiliary latch deadlocks the latchbolt. The inside grip always free. The outside grip remains locked unless unlocked by key either side.
- Schlage L9060 mortise locks can be used for classroom security as the latchbolt is retracted by lever from either side unless outside is locked by key from the inside. When locked, latchbolt is retracted by key outside or the inside lever. Only the inside lock cylinder can unlock the outside lever for keyless operation. The inside cylinder is also used to lock the outside lever. Inside lever is always free for immediate egress.
These types of locks help to keep people safer during an emergency by eliminating the need to open the door in order to lock the outside lever.
To further increase the level of security for some mortise locks, the standard outside lever or knob can be removed and an anti-vandal handle can be installed.
Some lock manufacturers offer mechanical lock function modification kits. This could save money, as existing locks may be able to be upgraded to the security function without having to replace the locks themselves.
The advent of the electromechanical lockset brought a new set of opportunities and limitations. Early electromechanical locksets were standalone, battery operated locks whose programming occurred at the keypad or credential reader on the exterior of the door.
Note: Most electromechanical locks have a mechanical override lock cylinder. Having a key enables access. For the purpose of this article, we will be discussing electromechanical locks that are capable of operating offline, as standalone locks.
Some manufacturers have begun to offer specialty-function battery operated locks that have the ability to provide lockdown without having access to the outside keypad and/or credential reader.
Alarm Lock Trilogy DL/PDL4100 Series cylindrical and DL/PDL4500 Series mortise locks have a lock down/privacy pushbutton on the inner assembly. Pressing this Trilogy’s inside ‘privacy’ button automatically disables free passage through the door and locks out general PIN user codes or proximity IDs. Activation is confirmed with a red LED right over the button, on the inner door, and on one outside, beside the keypad. From the outside, a lock-down override code will reactivate the pushbutton keypad and credential reader.