US2137504A

US2137504A - Pickproof lock

Info

Publication number: US2137504A
Application number: US147811A
Authority: US
Inventors: John J O'connell
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-06-12
Filing date: 1937-06-12
Publication date: 1938-11-22
Anticipated expiration: 1955-11-22

Description

Nov. 22, 1938. J, J, OCQNNELL 2,137,504

PIGKPRooF Loox Filed Jun 12, 1957 l INVENTR A ,Jahn OConnel] TTORNEY5 Patented Nov. 22, 1938 UNITED STATES PATENT OFFICE 4 Claims.

The present invention relates to cylinder locks and more particularly'to cylinder locks wherein auxiliary means are provided for making the lock pick-proof.

An object of the present invention is a lock wherein auxiliary plungers are provided for securing the key plug against rotation 'and the auxiliary plungers carry means for securing them when in locking position. Another object is a lock of this type wherein the auxiliary plungers may be readily reset to released position. A further object is a lock of this type which may be made in very small sizes. These and other objects Will be readily understood from the following description with reference to the accompanying drawing, in which:

Fig. 1 is a sectional view of the preferred embodiment of the invention on the line I-I of Fig. 2;

Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary view of one auxiliary plunger of Fig. 1 in locking position;

Fig. 4 is a view of another embodiment of the invention on the line 4-4 of Fig. 5;

Fig. 5 is a sectional view on the line 5-5 of Fig. 4; and

Fig. 6 is a. top view of the plungers of Fig. 4.

Referring to the drawing, the lock comprises the usual barrel or cylinder 2, the key plug 4 having a keyway 6 therein, pin tumblers 8, drivers I0, driver springs I2, and cylinder slide I4. The drivers IIJ and pin tumblers 8 being so related that upon the insertion of the proper key the upper end of the pin tumblers 8 and lower end of the drivers I0 are alined with the periphery of the key plug 6 whereby turning of the key will rotate same. All the foregoing structure is common to locks of this type.

In accordance with the present invention there is provided (Fig. 1) a set of auxiliary plungers I6 arranged at an angle to the drivers I0 and carried in bores II of cylinder 2 and adapted to coact with pin tumblers 8 to lock the key plug should the lock be picked or an unauthorized key employed. Each plunger is provided with a double head, the top head I8 having a smaller diameter than the lower head 20, this construction allowing a split resilient ring 22 to be carried in the recess 2l between the heads. The bore is formed with a shoulder 25 on which rests a positioning and stop member 24 having an inside diameter approximately that of the top head I8 and an outside diameter greater than the lower head 2D, the lower end of the position- (Cl. 'l0-364) ing member also forming al stop 21. A spring 28 normally biases the plunger downward, the spring being held between head I8 and slide 30. With the construction shown the ring 22 may be set in recess 2| between heads I8 and 20 and held by positioning member 24, the entire assembly may then be inserted in the barrel 2, spring'. 28 and slide 30 then being positioned, whereupon the plunger will be positioned as shown in Figs. 1 l and 2. If the key plug 4. is turned without the proper key, plunger I6 will coact with one of the pin turnblers 8 whereupon spring ring 22 will expand beneath stop 2'I and lock the plunger in place as shown in Fig. 3. To reset it is only necessary to remove slide 30, drop out the parts and reassemble. This construction is particularly adaptable to very small locks such as those used in automobiles, and although only two plungers I6 have been shown it is apparent that one could be associated with each tumbler.

In the embodiment shown in Fig. 4 the auX- iliary plungers 32 are provided with an enlarged head 34 which, as shown, may be square or provided with any suitable means to make it nonrotatable. The auxiliary plungersI are biased by springs 3B and held in position by the usual socket closure 38. Each auxiliary plunger 32 is provided with a stop pin 40 which is biased against the wall of the barrel by a spring 42. Arranged at right angles to the plungers and alined with the stop pins 40 is an opening 44 one end of which is closed with a cap screw 4S. Thus if the auxiliary locking plunger moves to engage the key plug should same be turned without the proper key, the stop pin 40 will enter opening 44 and be limited in its movement by cap screw 46 and thus lock plunger 32 against movement. In like manner plunger 48 will be locked against movement by stop pin 43, which will enter opening 44 and abut head 34 of plunger 32. With this construction it is possible to reset the auxiliary plunger by removing closure 38, and then by removing cap screw 46 the stop pin 40 may be pushed back into plunger head 34 by any suitable wire and then raised into position, whereupon the next stop pin 40 may be repressed and the next auxiliary plunger reset. It is also possible to simply remove plug 46, push back the stop pin 40, and then raise the plunger by using any suitable picking tool.

As in the rst embodiment the auxiliary plungers and stop pins are assembled and then inserted in the sockets in a single operation. Although only two auxiliary plungers have been shown and their size has been enlarged for purposes of clear illustration, it is evident that one auxiliary plunger could be associated With each key plug tumbler I2.

As many changes could be made in the above construction and many apparently Widely different embodiments of this invention could be made Without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

The following is claimed:

l. A lock comprising a cylinder, a key plug rotatably mounted in the cylinder, a plurality of pin tumblers carried by the plug, a plurality of drivers carried by the cylinder and alinable With the pin tumblers in one position, a plurality of auxiliary plungers carried by the cylinder and alinable with the pin tumblers when the key plug is rotated from the first position, stop means carried by the auxiliary plungers and adapted to hold the same against movement when in engagement With the pin tumblers, and resilient means for operating said stop means.

2. A look comprising a cylinder, a key plug rotatably mounted in the cylinder, a plurality of pin tumblers carried by the plug, a plurality of drivers carried by the cylinder and alinable With the pin tumblers in one position, a plurality of auxiliary .plungers carried by the cylinder and alinable With the pin tumblers when the key plug is rotated from the first position, a resilient member carried by the plunger, means for maintaining the member in compressed position when the plunger is out of alinement with the pin tumblers and for allowing the same to expand when in alinement with the pin tumblers.

3. A lock comprising a cylinder, a key plug rotatably mounted in the cylinder, a plurality of pin tumblers carried by the key plug, a plurality of drivers carried by the cylinder `and alinable` with the pin tumblers in one position, a plurality of auxiliary plungers carried by the cylinder and alinable With the pin tumblers when rotated from the first position, said plungers having a double head and a recess between the heads, a resilient split ring carried in the recess, a positioning member adapted to t around the top head and hold said ring under compression when said plungers are out of alinement With the pin tumblers, said positioning member having a down- Wardly facing shoulder beneath which said ring Will expand when said plungers are in alinement With the pin tumblers.

4. A lock comprising a cylinder, a key plug rotatably mounted in the cylinder, a plurality of pin tumblers carried by the key plug and alinable with the pin tumblers in one position, a plurality of non-rotatable auxiliary plungers carried by the cylinder and alinable With the pin tumblers When the key plug is rotated from the first position, said cylinder having an opening therein at right angles to the plungers, a stop` member carried by said plungers and adapted to enter said opening when the plungers aline with the pin tumblers, and resilient means for operating said stop member.

JOHN J. OCONNELL.