Abstract: A key for use in a hierarchal lock system with an elongated body and selectively spaced notches cut on an elongated edge of the body. Two rows of discontinuous rib members are attached to each side of the elongated body of the key.

Abstract: A device for detecting entry or drilling attempts into cylinder locks. One or more housing bores not corresponding to core bores when the lock is in a neutral position having spring biased tripping pins connected to an alarm or indicator system and operable when an entry attempt is made not using a proper key or after having drilled-out the tumbler or tumbler and cylinder pins. The tripping pins detect the rotated cylinder having a space in the cylinder bore due an improperly made key or due to the cylinder bore having previously been emptied by the drilling operation.

Abstract: An improved cylinder lock which is very difficult to pick has at least one cylinder pin into which a set of shallow grooves has been cut as well as a deeper notch at one end of the pin. A boring is made in the cylinder at an angle to the boring of the cylinder pin and into which is placed an appropriately sized obstructing pin. The obstructing pin is free to drop into a recess made in the lock housing when the cylinder is locked. The process of attempting to pick the lock by rotating the cylinder slightly results in the obstructing pin sliding along the side of the V-shaped recess in the housing and thereby moving toward and engaging the notches in the body of the cylinder pin preventing unauthorized movement of the cylinder pin which would render the associated locking pin inoperative. When a legitimate key has been inserted into the cylinder, the cylinder pin moves to its fully unlocked position before the cylinder rotation is initiated.