Pick-proof lock mechanism

Abstract

A pick proof lock mechanism for doors, consisting primarily of spring loaded pin members with expandable doors and a two piece key with a slip band.

Description

This invention relates to locks and more particularly to a pick proof lock mechanism of cylinder type.

It is therefore a principal object of this invention to provide a lock mechanism which will be pick proof and which will have expandable portions and pin means on its interior that when incorporated with a two piece key will prevent a prospective burglar from picking the lock.

Another object of this invention is to provide a pick proof lock mechanism which will be of such structure so that it will be impossible to insert anything between the door portions of the mechanism, without forcing the lugs out into a groove beyond the outer diameter of the core, thus stopping the rotation of either the door portions or the core and the door portions are held closed by the pressure from the spring loaded pins of the mechanism.

Still another object of this invention is to provide a lock mechanism of the type described of which the door members of the mechanism may not be drilled readily because the structure of the door members alignment will prevent the door members of the mechanism from aligning with the outer diameter of the core of the mechanism and punching the lock mechanism will have the same end result.

Yet another object of this invention is to provide a lock mechanism of the type described which will not be able to be picked because in order to pick a lock, the torque wrench used must be inserted into the core to hold tension on the pins while the pins are manipulated by bouncing them. The door members of the mechanism would have to be held opened for the torque wrench, therefore the outer diameters of the door members and the core will not be aligned.

Other objects of this invention are to provide a pick proof lock mechanism which is simple in design, adaptable to a majority of existing commercial cylinder type locks, inexpensive to manufacture, rugged in construction, easy to use and efficient in operation.

These and other objects will be readily evident upon a study of the following specification and the accompanying drawings wherein:

FIG. 1 is a front view of the present invention shown in elevation; with parts in the normal rest position;

FIG. 2 is a partial cross-sectional view taken along lines 2--2 of FIG. 3; showing relationship between doors and core groove;

FIG. 3 is a partial sectional view taken along lines 3--3 showing doors and blocks with pins and springs relationship to the adapter groove;

FIG. 4 is a cross-sectional and expanded plan view of the separatable door members of the invention showing interlocking feature of the door union and the rotational operated holes in the doors.

FIG. 5 is a cross-sectional view taken along lines 1--1 with the operational key inserted to show relationship between the key, core and functional pins;

FIG. 6 is an expanded view of components showing their relationship with each other;

FIG. 7 is an enlarged plan view of the twopiece key of the present invention shown with the two members separated;

FIG. 8 is a plan view of flexible slip band of present invention;

FIG. 9 is an end view of FIG. 7 in elevation.

According to this invention, a pick-proof lock mechanism 10 is shown to include a cylinder and core assembly 11 having a crush resistent ring 12. An adapter plate 14 is secured to cylinder place 13 by means of suitable screw fasteners 15 (see FIG. 2). A groove 11' is milled within cylinder face 13 (see FIGS. 1 and 6) for a purpose which hereinafter will be described.

Referring now more particularly to FIG. 3 of the drawing, one will see a pair of separatable door members 16 and 17 having overlapping step portions 17" for making engagement with each other. A pair of holes 18 are one each carried within the door in which extrusions 18' of key member 29 of key 28 will function as hereinafter will be described and member 16 and 17 cylinder face and a lug 19 is slideable within the slot 11' of cylinder face 13. The lugs 19 are carried within the groove 11' of the core 21 of mechanism 10.

The opening 22 receives a pair of plugs 23 which have holes 24 which slideably carries a pin 25 which is springingly urged inwards of mechanism 10 by means of a coil spring 26. Holes 24 are closed off by means of a press-fitted cap 27 and plugs 23 are retained within mechanism 10 by means of pins 23' within holes 23.1 in cylinder face 13's groove 11'.

Referring now to FIGS. 7, 8 and 9 of the drawings, one will see a key 28 having a member 29 with projections thereof, 30. The second number 31 of key 28 includes openings 32. The slip-band 31 of key 28 includes openings 32. The slip-band 33 is provided with a plurality of internal lands 34 and grooves 35 for accommodating key 28 in a manner which hereinafter will be described.

It shall be noted that lock mechanism 10 includes the conventional type cylinder 11 with core 21 and with the milled groove 11'. The lugs 19 on the rear of door 16 and 17 will ride within the groove 11' when the door member 16 and 17 are inserted into the groove 22. The plug members 23 are then assembled into the groove 22 along side the door member 16 and 17 and will be just held in place by suitable pins 23' fitted into holes 23.1 as shown in FIGS. 3 and 6 of the drawings. The pins 25 are inserted into the openings 24 and are followed by the springs 26 and then finally the press-fitted cap 27. The plate 14 with the aforementioned assembly contained within groove 22 is then positioned over the face of the conventional cylinder and core assembly 11. The door members 16 and 17 are fitted together when closed, by over-lapping as is more readily seen in FIG. 4 of the drawings.

It shall also be noted that due to the type of conventional cylinders and core assembly 11 used for illustration, the core face is recessed into the cylinder face and therefore necessitates a deeper lug penetration into the core face than if the conventional cylinder and core assembly had flush faces.

The two-piece key 28 is held together by means of slip band 33 for non-operational transport carrying only. In operation, the two-piece key 28's member 31 when inserted into the lock mechanism 10 will remain in the lock core 21 as shown in FIG. 5 thus aligning the conventional shear line 36' of the contained pins 36, thus preparing the core 21 for rotation which cannot take place until the front member 31 of the key 28 is fully inserted enabling the doors 16 and 17 outer diameter to become the same diameter as the core 21 outer diameter shown in FIG. 5. Also enabling lugs 19 of doors 16 and 17 to rotate within groove 11'. The core 21 and doors 16 and 17 must rotate together when projecting lugs 18' of key member 29 are inserted into the openings 18' into the doors 16 and 17 the heretoafter described enabling the combination to be rotated so as to activate the lock 10.

It shall be noted further that it is impossible to insert any thing between the door 16 and 17 without forcing lugs 19 out into the groove 11' beyond the outer diameter of the core 21 which will stop the rotation of either doors 16 and 17 or the core 21. The doors 16 and 17 are held closed with a pressure from the springs 26 and the loaded pins 25 in the plugs 23. The doors 16 and 17 cannot be drilled readily because construction of doors 16 and 17 alignment will again prevent the doors 16 and 17 diameter from aligning with the outer diameter of the core 21.

It shall also be recognized that with the heretofore described invention, unauthorized entry by picking cannot be successfully accomplished and difficult key duplication of the operating key 28 adds to the security benefits of the instant invention which are not founded in the prior art.

The key control lock 10 also has a removeable core 21 thus making it possible to change the key 28 to be used in connection with the lock 10 without having to dismantle lock 10 in its entirety.

Claims

What I now claim is:

1. A pick-proof lock mechanism, comprising in combination, a cylinder and core assembly for application to a door or the like, said cylinder and core assembly having a crush resistant ring, said cylinder and core assembly including a pair of separateable door members, said door members having over lapping step portions for making engagement with each other, said cylinder and core assembly including a pair of plugs having holes that slidably carry a pin which is springly urged inward of said lock mechanism by means of coil springs, said lock mechanism including a two piece key comprised of a first member and a second member, said first member having a series of projections on an end thereof, said projections being receivable in openings upon an end of said second member, said lock mechanism including a slip band of tubular character having long and terminal grooves and protrustions in a central opening thereof, said grooves and protrusions corresponding to a configuration of said two piece key in order to fit on said key and hold said key together, lugs on a rear of said doors riding within a groove of said cylinder and core assembly, said plug being in said groove alongside said door members and being held in place by said pins which are fitted holes located in said grooves, said coil springs being positioned over each said pin, and a press fit cap being positioned over said spring.

2. The combination as set forth in claim 1, wherein said key control lock has a removeable core thus making it possible to change said key without necessity to dismantle said pick proof lock mechanism in its entireity.