Abstract: A key according to the invention includes one or more bits which are offset forwardly or rearwardly of a corresponding tumbler axis of a twisting tumbler lock with dual locking function having tumbler points at tumbler positions selectively offset forwardly or rearwardly and selectively rotatable to different angular positions to create an enormous number of keying combinations.

Abstract: A cylinder lock of the type having twisting tumblers operated by a bitted key having at least one skew-cut bit provided with a side bar which is symmetrical with regard to a radius through a center of the key plug perpendicular to the plane of the key so that the side bar intersects not only slots in the twisting tumblers, but the profile of the key. The key has slots in its side face which extend perpendicular to its longitudinal axis.

Abstract: A twisting tumbler lock with dual locking function has tumbler points at tumbler positions selectively offset forwardly or rearwardly and selectively rotatable to different angular positions to create an enormous number of keying combinations. A key according to the invention includes one or more bits which are offset forwardly or rearwardly of a corresponding tumbler axis.

Abstract: A rim cylinder protection unit includes a single flat thick solid hardened steel guard plate counterbored to receive the rim of the cylinder. The cylinder is secured to the plate and prevented from rotation by cooperation with a cylinder retaining plate attached to the backside of the guard plate. The thick solid steel guard plate has heavy mounting studs welded by hardened material to the plate to extend through the door and these studs are protected by hardened steel sleeves to prevent burglars from chiseling through the studs. A replaceable cover conceals the rugged steel guard plate.

Abstract: A removable core cylinder lock utilizing twisting tumblers and a latch bar provides maximum security. Both operating and control keys have at least one skew cut bit to operating the twisting tumblers. A centrally positioned cylinder retainer is rotatable with a control key to remove the lock from its shell.

Abstract: A padlock of the type having a removable locking plug or cylinder capable of being removed from the top through a top opening in the lock case, also has a cap for the top opening. This cap is locked into the padlock case by a loose ball fitting in a groove in the cap and in the case. This cap locking ball is in addition to two other conventional locking balls used to lock the shackle in one conventional type padlock. The shackle is retained by another ball which is carried by a shackle leg and cooperates with another groove in the case. The shackle locking ball is placed in or out of locking position by adjustment of a set screw in the shackle leg.

Abstract: A closure for a padlock body containing a removably fixed lock cylinder primarily comprising a circular member having a concave recess in its perimeter coacting with the shorter leg of the padlock's shackle at the top of the padlock, the underside of the said member having a bayonet-like latch preventing the member from being withdrawn from the top of the padlock via coacting with the interior of the padlock body wherein the aforesaid lock cylinder is enclosed unless the member is rotated a predetermined amount, and the rotation of the member being prevented by the said leg of the shackle being in its proper socket in the body of the padlock in its locked position. The keyway to the lock cylinder for locking and unlocking the padlock is in the bottom of the padlock extending into the padlock body as is well known in the art.

Abstract: A cylinder lock with a key plug rotatably mounted in the cylinder shell is described. The key plug has a plurality of tumblers that are set by the V bits of a key inserted in the key plug. The key is cut at three different levels and cut at three different angles. Each tumbler in the key plug may be positioned by the properly bitted key reciprocally to clear the shear line and also positioned rotationally to allow the fence to be cammed out of engagement with the cylinder shell. The key plug may then be rotated.A side bar cylinder lock is also described with the same key cut at three different levels and cut at three different angles. The tumblers are positioned reciprocally and rotationally by the properly bitted key to allow the fence to be cammed out of engagement with the cylinder shell. The key plug may then be rotated.

Abstract: A closure for a padlock body containing a removably fixed lock cylinder primarily comprising a circular member having a concave recess in its perimeter coacting with the shorter leg of the padlock's shackle at the top of the padlock, the underside of the said member having a bayonet-like latch preventing the member from being withdrawn from the top of the padlock via coacting with the interior of the padlock body wherein the aforesaid lock cylinder is enclosed unless the member is rotated a predetermined amount, and the rotation of the member being prevented by the said leg of the shackle being in its proper socket in the body of the padlock in its locked position. The keyway to the lock cylinder for locking and unlocking the padlock is in the bottom of the padlock extending into the padlock body as is well known in the art.

Abstract: A removable core cylinder lock utilizing twisting tumblers and a latch bar provides maximum security. Both operating and control keys have at least one skew cut bit to operating the twisting tumblers. A centrally positioned cylinder retainer is rotatable with a control key to remove the lock from its shell.