1. Field of the Invention
The invention relates generally to apparatus for removal and replacement of mortice locks and similar locking structure with minimal damage to the lock. In particular, the invention relates to a drill template which allows rapid removal of the cylinder of a mortice lock without damage to the keyway.
2. Description of the Prior Art
Mortice and mortice thumbturn locks, as well as similar locking apparatus, are widely used, particularly in metal doors such as are common in commercial buildings including motels, hotels, stores, and the like. The mortice lock includes a cylinder which is held in the door by a set screw or cylinder yoke. From time to time, such locks need to be replaced for differing reasons. Various tools have previously been employed by the locksmith to remove such locks. These prior tools, which include pliers, vice grips, pipe wrenches, etc., unfailingly cause damage to and marring of the edges of the lock face. These previous practices typically result in the need for replacing the complete cylinder and, in many instances, the keyway itself which is expensive and often difficult to obtain since many such keyways are master keyed or otherwise keyed to form a part of a series of locks. Accordingly, in situations where mortice locks are to be removed, replaced or installed, it is desirable not only to cause as little cosmetic damage to the lock as possible, but is also necessary to prevent damage to the keyway due to the expense and difficulty of obtaining a new keyway or core which would have a pin setting compatible with locks already in place in a building or series of buildings. The present invention provides apparatus capable of facilitating the removal and replacement of standard mortice cylinder locks with minimal damage to the lock face and without damage to the core or keyway of the lock. Apparatus provided according to the invention includes a drill jig which allows the set screw or yoke of particular mortice locks to be cut away through the use of a simple drill.