US2338768A

US2338768A - Method and apparatus for decoding locks

Info

Publication number: US2338768A
Authority: US
Inventors: Theodore H Johnstone
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-08-03
Filing date: 1940-08-03
Publication date: 1944-01-11
Anticipated expiration: 1961-01-11

Description

1944- T. H. JOHNSTONE METHOD AND APPARATUS FOR DE CODING LOCKS Fi led Aug. 3, 1940 .5 INVENTORI aw-Mare EJ252132)! WA Patented Jan. 11, 1944 UNITED STATEg PTENT FFICE METHOD AND APPARATUS FOR DECODING LOC 9 Claims.

My invention relates to methods and apparatus for decoding locks, and particularly to a method for accurately exploring a lock to ascertain the and means for accurately exploring a lock to ascertain the shape of the key required to open the lock.

Difficulty has been experienced heretofore when keys were lost when attempting to open the look without damaging the lock or its support. No accurate means was heretofore provided which would permit one to accurately explore the lock tumblers of locks having certain protective features so as to ascertain the depth of the notches required in the key to have them conform to the length of the various tumblers. It was substantially impossible to make a key for such locks without damaging the lock or its support.

My method and apparatus permits the lock to be accurately explored and the depths on the key accurately found in a very short space of time. As a result a new key can quickly be made and the lock actuated and the door opened or a device actuated without any harm being done to either.

While there are several types of lock mechanisms well-known in the art, such as that employed in the pin tumbler lock, the lever lock, the wafer tumbler lock, and the combination look, all of these mechanisms operate on standard or basic principles. example, both pins and drivers areof solid cylinder construction and the bores in which these pins and drivers are mounted are uniformly cylindrical. Methods have been discovered for picking the locks having mechanism embodying this simple principle and manufacturers have devised various means to complicate the process. These means often take the form of special tumblers or drivers which are, in practically all cases, based on a specific system of arrangement which can be accurately controlled. The purpose of my apparatus is to discover the controlling element in a particular system which will allow an operator to determine the combination of the lock. This same system, with slight variations, may be employed in the types of locks abovementioned, and others not so specifically pointed out.

For a particular series of. locks. of the same design, a set of keys and picks have been illustrated by way of example with which any one of the locks of the series may be quickly analyzed. It is to be understood, however, that a single, instrument could be employed on whichv all of the notches. for the various depths of tumblers. ar

In the pin tumbler lock, for

mounted and shiftable in to any combination. Assuming a series of locks of the pin tumbler type having five tumblers of five depths are to be explored, drivers of the spool or mushroom type are employed with the tumblers of the 1st, 2nd, and 3rd depths, while cylindrical drivers are employed with the tumblers of the 4th and 5th depths. A locating key is first employed for ascertaining the amount of play between the plug and the cylinder which may be noted by a scratch marked on their faces. Thereafter, the keys of the series are tried in order to ascertain where the tumbler or tumblers of the fourth depth are located. Any tumbler of the fifth depth will naturally be mated with a notch cut to that depth on the key. When the key of the series has been selected which turns the plug, a small distance beyond that turned by the locating key, then it is knoWn for a certainty that the tumbler of fourth depth has been located. The tumblers of four and five depths will be located at the surface between the plug and cylinder and a movement beyond the mated marks occurs since the mushroom or spool type of drivers permit greater turning than that of the cylinder drivers which are no longer effective.

Three decoding picks are provided for the first, second and third depths and these are placed in the slot in the key and advanced to each of the remaining tumbler positions of the key. The lock is tried for each such position until, through the rotational movement of the plug beyond the normal amount, the tumblerfor that particular depth is located. Complete exploration of all of the tumblers occurs in a rapid manner and when all of the five positions of the tumblers are obtained a key can quickly be made having notches corresponding to the required depths which will be similar to the key originally furnished with the lock.

To maintain the keys in a proper order and to prevent the loss of any of the keys, I have provided a unique case in which a plurality of pins project to receive and support the keys. A cover having a plurality of openings through which the pins project is hinged to the side so that when the lid is closedthe pins will project through the lid and the keys will be prevented from shifting.

Accordingly, the main objects of my invention are: to provide a method by which the combination of a lock may be decoded; to provide a method which decodes a lock of the tumbler type by the process of elimination; to provide a series of keys which has all combinations of notches of fourth and fifth depth and mounting the keys in series so that in quickly running through the series the location of the fourth depth plunger may readily be ascertained; to provide a plurality of decoding picks with the keys by which the plungers of the first, second, and third depth may be explored; to provide a method and apparatus by which the plungers of fourth depth may be quickly ascertained and those of the first, second, and third depth thereafter explored which when located completes the analysis since the remaining depth notch or notches will be known to be of the fifth depth; to provide a case for containing a series of keys in properorder and locked in position when not in use so that there can be no disarrangement of the keys or loss thereof;

and in general, to provide a method of decoding locks which is simple, accurate, and positive.

Other objects and features of novelty of my invention will be either specifically pointed out or will become apparent when referring, for a better understanding of my invention, to the following description taken in conjunction with the accompanying drawing, wherein:

Figure 1 is a front view in elevation of a look cylinder for which a key is to be provided;

Fig. 2 is a sectional view of the structure illustrated in Fig. 1, taken on the line 2-2 thereof, with the drivers in normal locked position;

Fig. 3 is a view of the structure illustrated in Fig. 2, with a key and decoding pick in one position of exploration;

Fig. 4 is a view of the structure illustrated in Fig. 3 with the key and decoding pick in another position of exploration;

Fig. 5 is a view in elevation of a master key employed for ascertaining the amount of play between the plug and cylinder when all the drivers and tumblers are disposed in locked position;

Fig. 6 is a view of one of the series of keys employed to explore the plunger of the lock;

Fig. 7 is a view of another key of the series disclosing a position of the notch of fourth depth relative to those of the fifth depth;

Fig. 8 is a view of one of the decoding picks which are employed with the keys illustrated in Figs. 6 and 7;

Fig. 9 is a view of another of the decoding picks similar to that of Fig. 8 but having a projection of a different depth;

Fig. 10 is a View of a third decoding pick employed by the keys of Figs. 6 and '7 having a projection of still different depth;

Fig. 11 is a sectional view of the structure il- I lustrated in Fig. 2, taken on the line I ll I thereof;

Fig. 12 is a sectional view of the structure illustrated in Fig. 2, taken on the line I2--l2 thereof;

Fi 13 is a sectional view of the structure illustrated in Fig. 3, taken on the line I3-l3 thereof;

Fig. 14 is an enlarged sectional view of the structure illustrated in Fig. 6, taken on the line l4-|4 thereof;

Fig.'15 is an enlarged sectional view of the structure illustrated in Fig. 8, taken on the line l5-l 5 thereof;

Fig. 16 is a sectional view of structure, similar to that illustrated in Fig. 12, showing the position of the plug and cylinder during the exploring operation;

Fig. 17 is a view of structure, similar to that shown in Fig. 13 showing the relative position between the plug and cylinder housing during another phase of the exploring operation;

Fig. 18 is a perspective view of a key case employed for maintaining the keys in series and locked in position when transported; and

Fig. 19 is an enlarged sectional view of the structure illustrated in Fig. 18, taken on the line l9l 9 thereof.

In Fig. 1, I have illustrated a lock cylinder 2| comprising a mounting member 22 having a bore 23 in which a plug or rotatabl element 24 is mounted. The mounting member or housing is extended at 25 in which a series of apertures 25 are provided herein illustrated as five in num her. The apertures are aligned with a plurality of similar apertures 27 in the rotatable element or plug 24 which communicates with a key slot 28 extending longitudinally of the lug. Tumbler 29, 30, 3!, 32, and 33 are disposed within the

apertures

26 and 21, each plug being provided with a

driver

34, 35, 36, 31, and 38, respectively. Springs 39 are disposed between the series of drivers and the base of the slots 26 for urging the drivers and tumblers downwardly within the

apertures

25 and 21 to project within the key slot 28.

A key is provided for the slot having a series of notches or biddings of such depth as to conform to the length of the tumblers to thereby raise the tumblers to have the lin of abutment between the tumblers and drivers aligned with the surfaces between the housing 22 and the plug 24. In this position the plug may be turned within the housing to operate a lock bolt or other device by an operating projection 41. A locking element 42 projects into a slot 43 in the plug to prevent the relative longitudinal movement between the plug and the housing.

In older types of locks, the drivers were similar to the drivers 34 and 35 of th cylindrical type herein illustrated, which acted as guides to prevent too great a degree of movement between the plug and housing when the tumblers were in locked position. In view of the fact that these drivers were the same size, they could be held by friction between the plug and cylinder and by means of a vibrating or other device they could be forced upwardly an amount sufficient to have the abutting end of the tumbler aligned with the surfaces between the plug and housing, permitting an easy method of operating a lock. More recent drivers 36, 37, and 38, of the spool or mushroom type, were utilized which could not be bound between the wall of the

slots

26 and 2? when the plug was turned relative to the nous-- ing. The driver extended below the adjoining surfaces between the plug and the housing and when turned an amount illustrated in Fig. 16, the driver would catch upon the shoulder of the housing when moved upwardly and the method of operating locks by vibration could no longer be utilized. As a result, the locks employed today are dilficult to pick and a greater problem is presented when attempting to explore the tumblers and to make a new key for their operation.

In the example illustrated in Figs. 2, 3, and. 4, I have shown

tumblers

29, 30, 3|, 32, and 33 of depths five, four, three, two, and one, respectively. That is to say, the plungers vary in length from each other a predetermined amount, approximately .020 with the notch of fifth depth being approximately .0165 from the base of the key.

To explore the lock, a series of keys are provided having one, two, and three combinations.

of notches of fourth and fifth depth. In a lock cylinder of the type described, having five tumblers, 23 keys are required to provide such a series. The series of keys start with a key of five notches, all of the fifth depth. Thereafter, a notch of fourth depth forms a series of keys in all combinations with four notches of the fifth depth. The next series of keys is formed with two notches of the fourth depth in all possible positions with three notches of the fifth depth. A final series of keys is formed with three notches of the fourth depth in all possible positions with two notches of the fifth depth. It. is necessary to maintain the keysv in series and to explore the lock by employing the keys in proper series, otherwise in a lock having a single tumbler of the fourth depth, a key having two or three notches of the fourth depth would provide a. false reading. It is for this reason that applicant has provided a case for the keys which maintain them in accurate position at all times.

In Fig. 5, I have illustrated a key A l. which has been referred to as. a locating key. This key is provided with notches or biddings 45 all of which are of the fourth depth. It is known from the manufacturers code. that no lock is provided hav ing the plungers all the same depth and this key is employed to ascertain the amount of play between the plug 24 and the housing 22 when the tumblers are in locked position. When the drivers 34 and 35 are in locked position, preferably a scratch mark 45 is on the face of the plug 2A and housing 22 which indicates the maximum rotation of the plug 24 relative to the housing 22. After an operator becomes skilled in the use of the apparatus and method the scratch mark may be eliminated as the degree of rotation can readily be sensed after practice.

In Fig. 6, I have illustrated a key lhaving notches 48 which are all of the fifth depth. In Fig. 7, I have illustrated a key is having the first, third, fourth and fifth notches of the fifth depth while the second notch 45 is of the fourth depth. It is to be understood, as pointed out hereinabove, that the 23 keys provided have all combinations of 1, 2, or 3 notches 48 of the fifth depth. The series of keys are employed to locate the turnblers of the fourth depth, the tumblers of the fifth depth being automatically properly positioned although their locations are not initially known.

The tumblers of the first, second, and third depths are then found by the use of the decoding picks 5!, 52, and 53, illustrated in Figs. 8, 9, and 10, respectively. The pick 5| has a projection 54 simulating the first depth when the pick is attached to the key ll, 49, or any other key of the series. The picks 52 and 53 have projections 55 and 55 which simulate the second and third depths, respectively, when attached to a key of the series. The picks have a circular embossrnent 5'! on one side which. mate with one of a series of five apertures 58 on the key to position the projections 54, 55, and 55 relative to the five notches or biddings 48 so that the tumblers may be explored with a projection simulating the first, sec- 0nd, and third depth at any of the notches it of the fifth depth, the position of the notch of the fourth depth being known.

The ends of the projections 55, 55, and may be flanged as at 59 in Figs. 13 and 15 so as to project over the center of the key width and contact the base along the axis of the tumbler. The

base is usually rounded or of conical shape and a false reading may be obtained if engagement at the side of the axis occurred.

In employing the method and apparatus for decoding a lock, the key M is first employed to ascertain the amount of free movement between the. plug 24 and housing 22. The maximum degree of movement may be illustrated by a scratch mark 45 made on the face of the plug and housing. Thereafter, key #1 of the series is inserted in the lock and turned to ascertain whether a greater movement occurs between the plug 24 and housing 22. In the present example, the same degree of turning will occur the second key is then tried. This key will have the fourth depth position in the. first notch from the shoulder or left as viewed in the figure, and since the first tumbler 29 is of fifth depth the plug 2 will turn only the normal amount. Key #3 will then be tried and since this has a notch 45 of the fourth depth in the second position, the tumblers 2'9 and 35 will be moved upwardly until the line of abutment between the drivers t l and 35 and the tumblers will be aligned with the surface between the plug 24 and housing 22 and a greater degree of movement will occur therebetween. That difference in degree of movement is readily apparent from the positions of the plug and housing as illustrated in Figs. 16 and 17. In Fig. 1'7 a turning movement between the plug it and the housing 22 occurs only the normal amount as indicated by the scratch mark es. This occurs because the tumbler 29 of the fifth depth has been projected into the aperture When, however, the tumbler 29 is aligned with the surface between the plug and housing, as illustrated in Fig. 11, a

greater turning movement occurs, as illustrated in Fig. 16, since the mushroom type of drivers 36, 3?, and 3 8 are shouldered and will not bind between the wall of the apertures 25 and 2'! as occurred in Fig. 17. This movement of the plug 24 a greater amount relative to the housing 22, as indicated by the movement of the scratch mark on the plug beyond that on the housing, indicates that the fourth depth plungers have been located and that the fifth depth plungers are operated although their location is not known. It is now necessary to locate the plungers of first, second, and third depth and this is accomplished by the use of the picks 5!. 52. and 525.

The key #38 has the decoding pick 5! placed in the slot thereof with the projection 54 disposed initially at the first notch position. The key and pick are then inserted in the keyway and the key and plug turned to ascertain whether or not the turning produces a movement greater than that indicated by the scratch mark 46. Since the tumbler at the first stage is of fifth depth, the turning will be the same as when the scratch mark was placed on the tumbler and housing. The key and pick are then withdrawn and the projecting end 5 5 is moved to the third notch position, since it is known that the second notch position is of the fourth depth. Again, the key and pick are inserted in the plug and turned. In this instance, the turning movement will occur only an amount to align the scratch marks since it is known that a tumbler of the third depth is disposed in the third notch position.

The key and pick are again withdrawn from the plug and the projection 5% advanced at the fourth notch position and the key and pick again inserted in the slot. Upon turning the key, pick, and plug, a movement only will occur which will produce the alignment of thescratch marks in--.

dicating that the tumbler in the fourth position is of greater length than the first depth. The key and pick are again Withdrawn from the tumbler and the pick advanced until the projection 54 is in fifth notch position, or that shown in Fig. 4. In this position, upon turning the key, pick, and plug, the scratch mark on the plug will advance beyond that of the housing since the tumbler 33 is moved upwardly by the projection of the pick an amount to align its upper end with the surface between the plug and housing. Th reason for this difference between the degree of turning has been illustrated in Figs. 16 and 17 and has been described hereinabove. The picks are retained in exact position on the key by reason of the embossed projection 51 on the side of the picks engaging one of the five apertures 58 in the base of the slot in the key.

It is now known that No. 2 position has a tumbler of fourth depth while No. position has a tumbler of the first depth. The pick 52 for exploring the tumblers of the second depths is then utilized to explore the first, third, and fourth notch positions on the key. It will be found that the turning of the plug relative to the cylinder by the key with the projection 55 in notch positions 1 and 3 will be the minimum amount which aligns the scratch marks on the face of the plug and housing. In the fourth position, however, a greater turning movement between the plug and housing occurs, indicating that the fourth posi tion has a tumbler of the second depth.

There now remains the first and third notch positions on the key to be explored for tumblers. of the third depth. The pick 53 is then placed in the slot in the key 49 with the projection 56 thereof in the first notch position. The movement in this position will be the minimum amount which aligns the scratch marks on the face of the key. The key is then withdrawn and the pick is advanced to have its projection 56 moved to the third notch position. Upon turning of the key, pick, and plug, the scratch mark will move beyond the minimum amount, indicating that the third position contains a tumbler of the third depth. The first notch position will correspond to a tumbler of the fifth depth, since it has been explored for all of the other depths. As a result, it is now known that the tumblers in the first, second, third, fourth, and fifth notch positions are of the fifth, fourth, third, second, and first depths, respectively. After this is known, a key may be constructed, having notches in the various positions corresponding to the depth of the tumblers ascertained by my method as above pointed out in detail. When the tumbler 33 of the first depth is so short as to cause a rolling, rather than a tilting movement, I have obtained false readings which I have succeeded in overcoming by exploring for the tumblers 32 of second depth before those of the first depth.

While I have illustrated a cylinder lock of the tumbler type as being decoded by my method, it is to be understood that any lock having a series of elements to be moved by a key having notches of different depths may be decoded in a similar manner. It is also to be understood that when the key section is provided with different locating slots that a master slot can be provided in the key which will function in looks requiring keys having a series of slots. Some of the keys with the pick attached thereto will be capable of actually unlocking the look. This, however, will only be true for a portion of the combinations set up in the locks.

In the instant case, when only a single cylindrical driver is employed, as on the tumbler of the fifth depth and the tumbler of the fourth depth is provided with a mushroom driver, as illustrated on the tumblers of first, second, and third depths, then the pick may be eliminated and an instrument or a series of keys provided having notches of the fifth depth with all combinations of notches of the first, second, third, and fourth depth. The tumblers are explored by the instrument or the series of keys in the manner above pointed out but without the use of adjustable picks. The remaining tumbler or tumblers Will then be the one having the cylinder type of driver, which will be that of the fifth depth in the instant case.

The keys are preferably mounted in a case illustrated in Figs. 18 and 19. One side 63 of the case is provided with a plurality of pins 65 which project into apertures 66 in a cover 64 of the case. Hinges 68 join the cover to the side while a latch 69 is employed for retaining the cover in closed position. Wires, or similar elements, Bl are glued or otherwise secured to the edges of the side 63 of a depth equal to or greater than the thickness of the keys. The keys are furnished in series with suitable numerals or letters designating the sequence so as to be retained in order at all times. As a key is tried in the lock plug it is withdrawn, after the tests show it to be the Wrong key and hung on its peg 65 and the key next in order is then tried. In this manner the keys are kept in proper sequence and when the cover is locked in position the keys are prevented from shifting relative to each other.

While I have described and illustrated several embodiments of my invention, it will be apparent to those skilled in the art that various changes, omissions, additions, and substitutions may be made therein without departing from the spirit and scope of my invention, as set forth in the accompanying claims.

What I claim is:

1. A key body having a slot in one side face and a plurality of biddings along an edge capable of contacting tumblers in a lock, in combination with an element having a bidding, disposed in said slot and shiftable longitudinally thereof into any one of a plurality of positions.

2. A key body having a slot in one side face and a plurality of biddings along an edge capable of contacting tumblers in a lock, an element having a bidding disposed in said slot and shiftable longitudinally thereof into any one of a plurality of positions, and means for retaining said element in said position.

3. A series of keys for decoding locks which includes, in combination, key blanks having a slot in one side face and a plurality of b-iddings along one edge thereof, and a decoding pick disposable in said slot and having a bidding which is adjustable longitudinally thereof, the series of keys and pick being capable of setting up combinations of a series of locks.

4. A series of keys for decoding locks which includes, in combination, key blanks having a slot in one side face and a plurality of biddings along one edge thereof, a decoding pick disposable in said slot and having a bidding which is adjustable longitudinally thereof, and means for accurately positioning said pick in any of a plurality of relatively shiftable positions, the series of keys and pick being capable of setting up combinations of a series of locks.

5. The combination with a series of keys for decoding locks, said keys having a slot in one side face and a plurality of biddings along one edge thereof, a plurality of decoding picks for selective disposition in said slot and having a bidding which is adjustable longitudinally thereof, the series of keys and picks being capable of setting up combinations of a series of locks.

6. The combination with a series of keys having slots in one side face, said keys having a series of notches at predetermined points of different depth and in various combinations relative to each other, a series of elements having notches of diiferent depth from each other and from those in said keys disposable in the slot of said keys and shiftable longitudinally thereof, the series of keys and elements being capable of setting up all combinations of a series of locks.

7. The combination with a series of keys having slots in one side face, said keys having a series of notches at predetermined points of diiferent depth and in various combinations relative to each other, a series of elements having notches of different depth from each other and from those in said keys disposable in the slot of said keys and shiftable longitudinally thereof, and means for locking said elements on said keys in any of the adjustable positions, the series of keys and elements being capable of setting up all combinations of a series of locks.

8. The method of decoding a lock having a device containing a bore in which a rotatable plug is mounted and held in non-rotatable position by a group of elements, at least some of which are of the mushroom type, so positioned as to be actuated by members of varying lengths, which includes the steps; of first turning said plug in the device when in normal locked position to ascertain the normal movement thereof, and thereafter moving an element to difierent positions and turning said plug for ascertaining the position of the element when the plug turns an amount greater than said normal amount.

9. The method of decoding a lock having a device containing a bore in which a rotatable plug is mounted and held in non-rotatable position by a group of elements, at least some of which are of the mushroom type, so positioned as to be actuated by members of varying lengths, which includes the steps; of first turning said plug in the device when in normal locked position to ascertain the normal movement thereof, of moving some of said elements by members of the same lengths and turning said plug for ascertaining the position of any element corresponding to that length of member when the plug turns an amount greater than said normal amount, and repeating said last operation with members of other lengths to locate elements corresponding to said other lengths by the turning of the plug amounts greater than said normal amount.

THEODORE H. J OHNSTONE.