US 4,061,004 AGranted

Pick-proof lock cylinder and key therefor

OwnerGeorge Pappanikolaouinventor

Life of this patent

Estimating the term…

Loading patent…

Abstract

A pick-proof lock cylinder and key therefor are described. The lock cylinder has a keyhole which opens to provide access to the cylinder, and two cam surfaces are provided at the remote end of the keyhole configurated to deflect a pair of coded, pivotally mounted fingers on a jointed key which is receivable within the keyhole. The revolving cylinder or tumbler includes a plurality of enabling pins or plungers which are generally spaced from each other along a direction substantially normal to the length direction of the keyhole. The fingers of the key may be mechanically or magnetically coded to cause the enabling pins or plungers to be actuated when the key is fully inserted into the keyhole and the coded fingers are deflected to their operative positions by the cam surfaces. Additionally, sensing or monitoring pins enable the proper actuation of the enabling pins or plungers only upon detection of a suitably coded key. Additional pick-proof pins are provided for preventing picking of the lock by indiscriminate actuation of all of the enabling pins or plungers. Provision is also made for alarm means which includes one or more switches arranged to sense the relative positions of the tumbler, the sensing or monitoring pins, as well as a plurality of additional sensing or alarm disabling rods whch are mounted for detecting a preselected code placed on the shank of the key.

Claims30

Dependent claims

A lock cylinder for use with a jointed key generally defining an axis and having at least one pivotally mounted coded finger which is movable between an initial position substantially parallel to said axis and a final position substantially normal to said axis, said lock cylinder comprising an external housing having two coaxial cylindrical cavities in communication with each other, one of said cylindrical cavities defining a keyhole for the jointed key and having an opening to the exterior of said external housing at one end and a remote end proximate to the other of said two cavities, said keyhole having a diameter generally smaller than that of said other cavity;

a revolving cylinder disposed beyond said remote end of said keyhole and having a diameter generally corresponding to that of said other cavity and mounted only for free coaxial rotation therein;
means mounted on said revolving cylinder for common rotation therewith and adapted to cooperate with an associated lock mechanism, said revolving cylinder being provided with at least one cam surface generally facing said one of said cavities and having a surface portion proximate thereto whereby insertion of the jointed key into said lock cylinder causes said finger to initially abut against said cam surface portion, said cam surface being configured to move said finger from said initial position to said final position upon full insertion of the jointed key into said lock cylinder;
and decoding means spaced from the axis of said cavities and cooperating with said external housing and said revolving cylinder for normally preventing said revolving cylinder from rotating relative to said external housing and permitting the same to rotate only when said decoding means detects an appropriate code on said finger in said final position of said finger.

Dependencies are inferred from the claim text.