In this article, a tough new Marks USA Protector Series LA118J Classroom Maximum Security Mortise Lock is installed onto a pre-prepped wood mount. For added strength, the sample LA118J is equipped with exterior and interior lever override guard. To put it simply, door locks take a beating...
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In this article, a tough new Marks USA Protector Series LA118J Classroom Maximum
Security Mortise Lock is installed onto a pre-prepped wood mount. For added strength, the sample LA118J is equipped with exterior and interior lever override guard.
To put it simply, door locks take a beating, even in the normal day-to-day operation. Drooping levers and loose knobs are some of the more common results of heavy-handed operations. With these problems and an increasing amount of vandalism, the average door lock does not stand a chance.
As a solution, Marks USA has designed the Protector Series mortise locks to withstand high traffic and abusive situations. These ANSI specification A156.13-2002, series 1000, Grade 1 mortise locks"have a minimum of 1.5 million life cycle test," according to Marks. They are UL Listed three-hour fire rating, and can be ordered with levers that meet the ADA, Life Safety, and local jurisdictions.
To maintain longevity, Marks USA cast stainless steel latches and deadbolts are standard. The stainless steel latch has a 3/4" throw and is field-reversible. Friction-proof fingers are designed to reduce the amount of pressure required to retract the latch in order to close the door. The stainless steel deadbolt provides a stronger lock mechanism between the door and the jamb. In addition, each deadbolt is equipped with two hardened steel pins to resist sawing.
To increase the level of security, the Protector Series comes standard with 1/8" thick stainless steel trim plates and levers. This trim is secured to the door with four thru-bolts from the interior side of the door. Four tamper-resistant screws thread into four 1/4" diameter screw posts welded onto the exterior trim. The two center bolts pass through the lock body approximately one-half inch above and below the hub mechanism. This thru bolting helps to align the mortise cylinder, the trim plates, and the levers to the lock body during installation. The levers are interconnected to the trim plates, requiring the trim to be taken off the door before a lever can be removed. Each lever is connected to the hub mechanism with a separate spring-loaded spindle. The spindles slide into individual slots on each side of the lock body.
The standard Protector Series mortise lock is equipped with a surface-mounted lever override guard on the exterior side of lock body. The lever override guard is metal plate affixed to a spindle. Rotating the lever rotates the lever override guard between the two center screw posts. The shape of the lever override guard limits rotation, contacting one of the screw posts at a rotation of approximately 60 degrees. When locked, the hub locking mechanism slides into a slot in the exterior override guard, preventing rotation at the lever override guard.
When excessive force is applied to the lever, the spindle absorbs the force."When excessive torque is applied, the spindle will eventually break usually without causing damage to any other part," according to Marks USA. For high abuse applications, the Protector Series mortise locks are available with an interior override guard.
For this article, we will install a Marks USA Protector Series LA118J Mortise Lock onto a pre-prepped wood mount. The LA118 indicates the American lever. The"J" indicates Classroom function, ANSI F05, key locked/unlocked from the exterior, with the interior always free for immediate exit. The sample LA118J was equipped with exterior and interior lever override guard.
Note: For new installation, the use of a door mortiser will simplify the installation. If a door mortiser is not available, a sharp one-inch wood bit is required to drill six adjacent holes along the middle of the door edge. Use a sharp chisel to remove excess wood from the mortise pocket. Remove the material for the front. Once the mortise lock fits into the door edge, mark the locations for the levers, lock cylinder, and thru-bolts.
This modification provided the capability of a deadbolt and dead latch in one lock (mortise) mechanism while maintaining the integrity of the door.