Pick-resistant wafer tumbler lock with sidebars
AssigneeMaster Lock Company LLC
InventorsBilly Edwards, James Welch
Life of this patent
Estimating the term…
Abstract
The invention provides a pick-resistant locking mechanism with wafer tumblers, sidebars and an interchangeable cylinder that allows re-keying of the lock. The sidebars have projections with beveled sides that engage with cavities in the lock shell when rotational torque is applied to the lock in the absence of the correct key. A sidebar of the lock contacts two, nonadjacent wafer tumblers. The wafer tumblers have indentations that engage cavities in the lock shell when rotational torque is applied during picking of the lock. Tolerance between sidebars and the lock shell is less than the tolerance between tumblers and the lock shell. The tumbler springs are not accessible from the keyway of the lock and are more powerful than the sidebar springs.
Claims24
A locking mechanism comprising:
- a shell;
- a lock cylinder having a keyway therein and rotatably disposed within said shell;
- a plurality of spring-loaded tumblers contained within said lock cylinder and selectively engageable with said shell;
- and
- at least two spring-loaded sidebars positioned for engagement with said spring-loaded tumblers and selectively engagement with said shell, wherein each sidebar has a surface forming a camming surface with said shell.
A locking mechanism comprising:
- a lock housing;
- a lock cylinder having a keyway therein and rotatably disposed within said lock housing;
- a plurality of spring loaded tumblers disposed with said lock cylinder;
- and
- two or more spring-loaded sidebars disposed within said lock cylinder and engaging said tumblers, wherein the sidebars have a projection with beveled sides forming a camming surface with the lock housing, and wherein each sidebar contacts non-adjacent tumblers.
An elongated, spring-loaded sidebar for a tumbler locking mechanism comprising one or more projections that selectively engage a cavity in a lock shell.
An elongated, spring-loaded sidebar for a tumbler locking mechanism comprising one or more projections that engage two or more nonadjacent tumblers.
A removable lock cylinder comprising:
- a cylinder plug with at least one external notch;
- a plurality of spring-loaded wafer tumblers which fit within the cylinder plug;
- one or more spring-loaded sidebars which fit within the cylinder plug and engage two or more non-adjacent tumblers;
- and
- a tumbler for locking the cylinder assembly within the lock shell.
Dependencies are inferred from the claim text.