US 3727439 A
A key lock which can be produced in modular form with standardized tumblers. The tumblers are levers which have bendable or deformable portions, and are fitted to a particular cut key by inserting the key into the lock and turning it while the tumblers are held against turning in predetermined position. This displaces the bendable portions of the tumblers to new positions corresponding to the respective lift heights of the key which is used to carry out the bending.
Description (OCR text may contain errors)
United States Patent Parrock 5] Apr. 17, 197 3 [5 MODULAR KEY LOCK HAVING 1,953,535 4/1934 Hurd ..29/445 LEVER TU E WITH BENDABLE 3,208,248 9/1965 Twice... ..70/383 3,315,503 4/1967 Schlage ..70/383 Inventor: Joseph J. Pal-rock, Milford, Ohio The Mosler Safe Company, Hamilton, Ohio Filed: Jan. 31, 1972 Appl. No.: 222,153
US. Cl ..70/355, 70/383 Int. Cl. ..E05b 25/00 Field of Search ..70/355, 376, 377,
References Cited UNITED STATES PATENTS 3/1932 l-leyer ..70/377 X Primary ExaminerRobert L. Wolfe Attorney-James S. l-light et a].
[ ABSTRACT A key lock which can be produced in modular form with standardized tumblers. The tumblers are levers which have bendable or deformable portions, and are fitted to a particular cut key by inserting the key into the lock and turning it while the tumblers are held against turning in predetermined position. This displaces the bendable portions of the tumblers to new positions corresponding to the respective lift heights of the key which is used to carry out the bending.
15 Claims, 7 Drawing Figures PATENTEU APR SHEET 1 [IF 2 MODULAR KEY LOCK HAVING LEVER TUMBLERS WITH BENDABLE PORTIONS This invention relates to key locks of the lever tumbler type, that is, the type which includes at least one set of tumblers in the form of levers mounted for swinging movement about an axis, in response to the turning of a cut key. The invention is particularly concerned with a lock of the type described which can be produced in a standard or modular condition, not fitted to any particular key at the time it is assembled, and which thereafter can be set to any of a very large number of keys by the initial turning of any key which is selected.
The conventional key lock of the lever tumbler type includes a plurality of tumblers which are mounted for rotation about a fixed post in the lock case, with each tumbler having a gate or open slot at one end. The levers are turned about the post by a corresponding key to angular positions such that the gates of the respective tumblers are disposed in alignment to receive the bolt, and thereby permit the latter to be withdrawn. Springs urge the tumblers toward a stop and, when no key acts on the tumblers, hold them against the stop. In this rest" mode, the stop positions the tumblers so that their gates are disaligned with respect to the bolt, and the tumblers thereby block withdrawal 'of the bolt. The
gates are formed at different positions on the different I tumblers, so that each tumbler must be turned a different amount by the key in order to align its gate with the bolt. Thus, the different lifts of the key turn the different tumblers through different angles about the post, sufficiently to bring all of the gates into bolt alignment.
To coordinate each conventional lock to the particular key with which it is to be used, the lock must be assembled with tumblers having gates at such positions that they will be aligned by the respective lifts of the key to be used. The keys lifts are cut according to a random schedule, and the lifts differ from key to key and on each individual key. Thus, each key requires a different specific set of tumblers to respond properly and be aligned by it. Literally, each lock has heretofore necessarily been built to fit one and only one key. Obviously, this has necessitated close and painstaking correlation between key and lock during lock assembly.
As can be appreciated, it is desirable to simplify lock construction to enable locks to be produced in a standardized form, without the previous requirement of individualized key-tumbler correlation, and such that as produced, all locks would be substantially identical to one another and could be fitted to different keys after assembly.
The desirability of such standardization is especially great in locks for safety deposit vaults, wherein hundreds or even thousands of locks are used, each of which requires two different keys, a bank or guard key and a customer key.
it has been a principal objective of this invention to provide a lock construction such that the lock manufacturer can build standardized locks with each tumbler identical, and which can thereafter be set or fitted to any of many different keys, merely by inserting a particular key in the lock and turning it.
The invention centers around a lever tumbler which can yield by bending in response to the initial or setting operation of the key with which it is to be used. The
bendable part of the new tumbler is a key-engaging portion. Prior to bending of this portion, it coacts with a stop against which the tumbler rests in one position; in bending, it is moved so that the tumbler thereafter rests in a different position. The surface on the tumbler which engages the stop prior to bending can be considered to be a first active stop-engaging surface. After the bending, a second stop-engaging surface becomes active. The lock is constructed of tumblers in the unbent, undeformed condition, and the respective tumblers are fitted to the corresponding lifts of the particular key by turning the key which causes the bendable portions of the tumblers to be bent.
The new tumbler comprises a lever which in assembly is mounted on a post for rotation around the post in response to turning of the key. At one end a gate is formed in the tumbler, shaped to receive the bolt when the tumbler is properly aligned, and thereby permit the bolt to be retracted.
The key-engaging portion of the tumbler is narrow or is connected to the tumbler by a narrow neck which can yield in bending. This portion is disposed to be bent when the key is first turned while the tumbler is held against turning. As manufactured, the key-engaging portion is in a position such that it will be engaged by the key, regardless of the depth of the particular key lift. Prior to first usage, the first stop-engaging surface of the tumbler rests, under the influence of a bias spring, against stop means in the case. The first stop-engaging surface positions the tumbler so that its gate is either aligned with the bolt, or is in a predetermined position with respect to the bolt. By turning the key while the tumbler is held against movement, the keyengaging portion is bent to a new position with respect to the remainder of the tumbler, the amount of the bending depending upon and varying with the depth of the particular lift of the key.
In the new or bent position, the first stop-engaging surface is rendered inactive or is displaced from its original position, and does not rest against the stop means at the same point. The second stop-engaging surface becomes the active stop surface, and is urged by the bias spring to a rest position in which it resides against the stop means, at an angular position such that the tumbler gate is disaligned with the bolt. Thereafter, to align the gate of that tumbler with the bolt, the proper key must be used, to bear on the key edge of the tumbler and turn the tumbler against the spring bias, to bring the gate into the proper position.
In a preferred embodiment, the key-engaging portion of the tumbler provides the first stop-engaging surface, which coacts with a first stop in the lock case. When the bendable portion is bent by the key, this first stopsecond stop-engaging surface on an unbent part of was made It is recognized that other locks having bendable tumbler portions are known. Schlage US. Pat. No. 3,315,503 shows a construction cylinder lock having tumblers in the form of pins which can be bent to shorten their effective length and thereby change them from fitting a first key, to fit a second key. A specially fitted first key is required to open the lock, prior to patent contains no disclosure concerning lever tumblers.
In Hurd US. Pat. No. 1,953,535, pin tumblers are shown which can be broken along predetermined lines so as to fit the lock to an individual key. Again the number of possible keys to which the lock can be fitted is relatively limited.
In Nawn, U.S. Pat. No. 2,025,293, a sliding tumbler for a cylinder lock is shown which has an end portion that is bent or arched. This is said to accommodate the irregularlyserrated edge of a key, so that the tumbler will glide readily over horizontalledges parallel to the keys transverse edge. The purpose is not to fit the lock to any of a large number of keys, but rather to render the lock operable by duplicate keys which differ only minutely.- I
In US. Pat. No. 1,840,323 there is disclosed a cylinder lock having sliding tumblers in which the tumblers are bendable. However, the bendable portions cannot be bent by use of the key, but must be compressed against the key by means of a special assembly tool; US. Pat. No. 2,058,853 is a further variant on that concept.
Quillen US. Pat. No. 3,255,620 shows a lock having a tumbler made from a material which can be bent, but the tumbler is resilient or elastic, and returns to its neutral position when freed. The bending is reversible, in contrast to the present lock, in which the tumbler is permanently deformed by the bending in order to retain its fit to the corresponding key.
As an example of its utility, the lock embodying the invention is especially useful in two key locks of the type used with safety deposit boxes. Since the invention in that environment, it is described hereinafter primarily in relation to safety deposit box locks, but it should be understood that the invention is not limited to that use.
Safety deposit box locks commonly require use of two different keys, before the box can be opened. One key, which is retained by the bank or the guard, is used first and aligns one set of tumblers. A second key, which is retained by the particular customer, must then be used to operate another set of tumblers. All the tumblers of both sets must be in their proper alignments before the bolt can be withdrawn. This prevents opening of the box by either the bank alone, or the customer alone.
Ordinarily all the boxes in a given installation will be fitted to the same guard key, so that the guard need only carry one key to operate the guard tumblers of all the locks. Different banks of course have difierent guard keys. Each customers key is different, so that each customers key can open only one single lock.
The fact that two keys are used with two sets of tumblers has caused complications in the assembly of safety deposit locks. Heretofore, in order to provide locks to fill a specific banks requirements, the manufacturer has had to assemble all the locks to the particular banks guard key, and each lock to a different customers key. The locks could be assembled only after the specific banks order was placed; this was necessary to match the guard tumblers to the particular banks guard key. This caused substantial delay in delivery, since renewal lock orders had to include the necessary guard key information so that the tumblers could be matched at the factory assembly operation. It was virtually impossible to assemble locks for inventory in advance of order, since the guard key shape was not known in advance.
The tumblers of this invention can usefully be employed to comprise each tumbler of the set which is operated by the guard key. More generally, tumblers in accordance with the invention are useful in either or both sets of tumblers, that is, as either the guard tumblers or the customer tumblers or both in a safety deposit lock, or they can be used in single key locks. The new tumblers may comprise a portion, less than all, of any tumbler set in which they are used.
The invention can best be further described by reference to the accompanying drawings in which:
FIG. 1 is a fragmentary perspective view of a portion of a multiple safety deposit box installation and shows a typical environment of a preferred form of safety deposit lock in accordance with the invention;
FIG. 2 is a horizontal section through a preferred form of safety deposit box lock and is taken on line 2- 2 of FIG. 1;
FIG. 3 is a plan of a guard tumbler including the features of the invention, as used in the preferred embodiment;
FIG. 4 is a vertical section taken on line 4-4 of FIG. 2 and shows a guard tumbler prior to bending, with the bolt retracted and the bit'engagecl in the gates of the guard and customer tumblers;
FIG. 5 is a view similar to FIG. 4, but shows the guard deposit box type. For that reason, this preferred embodiment of the invention is described with relation to such locks, although it should be understood that th invention is not limited to two key locks.
The safety deposit box installation shown in FIG. 1
includes a plurality of lockable doors, each designated lock shown for purposes of illustration, the nose 14 receives the so-called customer or locking key, and nose 15 receives the guard key, but this order could reversed.
In keeping with the usual practice, a guard key, which is retained by the bank or guard, will operate guard tumblers of the locks on all of the doors 10, and each box requires its own individualized customer key to operate customer or locking tumblers. Both the customer and guard tumblers must be aligned before the bolt can be withdrawn.
FIGS. 2 and 4-6 show the arrangement of the guard and customer tumblers within a lock. The lock 18 is fastened by machine screws 19 to the inside surface of the box door 10, and is contained within a two part housing which includes a case 20 and a lid or cover plate 21. The lid 21 is disposed facially against the inside surface of the door 10. The two noses 14 and 15 are mounted to the lid, and project into cooperating apertures formed in the door 10, substantially to the surface of the lock door, and receive the customer and guard keys respectively.
A key post 24 (which receives the customer key) and a key post 25 (which receives the guard key) are rotatably supported at their opposite ends between the noses l4 and 15, and apertures 26, 26 in the bottom of the case 20. Each key post 24, 25 has an elongated shank portion 28, a smaller diameter neck 29 which is seated in the case aperture 26, and an enlarged stepped head 30 which is carried and retained by a flange or rim in the respective nose 14 or 15. Thus each key post 24 and 25 is rotatable within its respective journals, but cannot shift axially. As shown in FIGS. 46, each key post 24 and 25 is slotted along its length, as at 32, to receive the respective key. The customer and guard keys are designated at 34 and 35 respectively in FIGS. 4 and 5, in which they are shown inserted within their respective key posts.
A fixed post or pivot 38 projects from the inner or back surface of the lock case toward lid 21 (see FIG. 2), and a screw 39 which passes through the lid is threaded into this post 38 to hold the lid and case in closed relation prior to fitting to the particular door 10. As will be seen, this post 38 conveniently serves as the pivot for each of the two sets of tumblers to be described.
Lock case 20 has an endwise opening through which the bolt 41 extends. The bolt includes a bolt pin or racking pin at 42, and is movable between a retracted position (shown in FIG. 4) and an extended position (shown in FIG. 2). The bolt contains a slot 43 indicated by the dotted lines in FIGS. 4-6. Post 38 extends through an elongated portion 48 of slot 43, and supports and guides the bolt for sliding movement between the retracted and extended positions. Bolt slot 43 also includes a portion 44 (see FIG. 5) which is engaged by and cooperates with a bolt thrower in the form of a key bit or foot 45 that is mounted at the inner end of a customer key post 24. A stub or pin 46 on the lock case bottom limits the angular rotation of the dog in the clockwise direction, see FIGS. 4 and 5, and hence the retracted position of the bolt. The end of slot portion 48 fixes the extended position of the bolt.
The lock includes-a set of guard tumblers, which are operated by the guard key, and a set of customer or locking tumblers which are operated by the customer key. Either or both of these sets of tumblers may have a bendable stop feature in accordance with the invention; in the embodiment illustrated, this feature is used on the guard tumblers only, and the customer tumblers are conventional. v
The customer tumblers are designated at 49 and the new tumblers, used as the guard tumblers are designated at 50. In the particular lock shown, there are seven tumblers of each type, and they are arranged alternately with one another within the case, but it is pointed out that neither of the number nor the order of arrangement is critical. All of the tumblers 49 and 50 are levers which are pivotable about post 38.
As shown in FIG. 2, the tumblers of the different sets are interleaved with one another on post 38; a customer tumbler 49 is adjacent the lid, then a guard tumbler, then a second customer tumbler, etc.
Only a single guard tumbler and a single customer tumbler are shown in FIGS. 4-6, to simplify those drawings, but it will be apparent that the other tumblers of the respective set can be similar in outline form, except that they vary from tumbler to tumbler in respect to gate position, and hence, position of alignment.
The customer tumbler 49 is suitably in the form of a thin flat member having an aperture by which it is journalled for rotation about post 38. At one end the tumbler includes a gate 53 shaped toreceive the racking pin 42 of the bolt when properly aligned therewith. A bias spring 54 urges the customer tumbler in the counterclockwise direction around post 38, toward a rest position in which a stop-engaging surface 55 bears against and is arrested by the side of the customer key post 24 (see FIG. 6). In the locked condition, spring 54 holds the customer tumbler 49 in this position with the stop-engaging surface 55 against the customer key post; as shown in FIG. 6, in this position the gate 53 of the customer tumbler 59 is disaligned with respect to the racking pin 42. Thus the customer tumbler will block withdrawal of the bolt, since the pin 42 would bump against the end surface 56 of the tumbler.
When the customer key 34 is inserted in the slot 32 in the customer key post 24 and turned clockwise, the particular lift of the key that is positioned under the respective customer tumbler bears upon a key-engaging surface 57 of the tumbler and turns the tumbler clockwise around post 38 (compare FIGS. 6 and 4). As this occurs, it can be seen that the gate 53 is swung upward to a position such that the gate is properly aligned to receive the bolt as shown in FIG. 4. (This illustrates the need for proper correlation of tumbler and key; if an improper key were used, the tumbler would be turned by the lift of the key an amount which does not move the gate into alignment to receive the bolt.)
The guard tumbler 50 having the bendable feature in accordance with the invention is shown in plan form in FIG. 3. The lock is assembled with all of its guard tumblers in the unbent condition, shown in this figure. Like the customer tumbler 49, this tumbler is flat and relatively thin, and is mounted for rotation on post 38, which passes through an aperture 60 in the tumbler. The tumbler has a gate 61 formed in its end and is biased in clockwise direction about post 38 by a bias spring 62.
In contrast to the customer tumbler, the guard tumbler has two stop-engaging surfaces, a first or initially active stopaengaging surface 63 and a second or subsequently active stop-engaging surface 64. These surfaces 63 and 64 coact with first and second stops which comprise, respectively, the guard and customer key posts and 24. The second stop-engaging surface 64 can correspond generally to the stop-engaging surface 55 of the customer tumbler, which bears on the opposite of the customer key post 24 (see FIG. 6).
The guard tumbler has a guard key-engaging portion 65 which is presented on an elongated arm 66 that is bendable with respect to the remainder of the customer tumbler. This arm 66 also presents the first stop-engaging surface 63. Specifically, the arm 66 is connected to the tumbler by a narrow neck 67, which can be bent so that the key-engaging portion 65, and the first stop-engaging surface 63, assume a different position with respect to the gate and the second stop-engaging surface 64 (compare FIG. 5, in which arm 66 has been bent, with FIG. 4, which shows arm 66 in the unbent or as manufactured position).
Prior to bending'the tumbler to fit the key, the first stop-engaging surface 63 is the active stop, that is, the one which controls the tumbler rest position. The bias spring 62 urges the tumbler clockwise around post 38 to a position which stop surface 63 rests against the guard key post 25 (see FIG. 4). It can be seen that in this position the second stop-engaging surface 64 is in active, that is, it is spaced from and does not contact the second stop, i.e., the customer key post 24. In this position the gate 61 of the guard tumbler is disposed in alignment to receive the racking pin 42. Thus, prior to setting to a particular guard key, use of the customer key alone will suffice to retract the bolt, since the guard tumblers are already aligned. When the guard key is inserted in its slot 32 in the guard key post 25, and the key turned, the liftof the key-regardless of its height-will come into engagement with the key-engaging portion portion 65 and will stress that portion outwardly thereby causing the neck 67 to bend and stop surface 63 to be moved. In this embodiment the key bears on the first stop-engaging surface 63, and the key post 25 acts as the first stop. However, it is pointed out that the stop surface could be spaced from the key edge and could coact with a stop separate from the key post.
To permit the necessary bending, the material of which the tumbler is made should not be resilient to the stress placed on it, but should be permanently deformed by it so that the key displaces the key-engaging portion. 65 and the first stop surface 63 to a new position (as indicated in FIG. 6) which will substantially be retained when the key is withdrawn. A suitable material is copper alloy No. 342, a high leaded brass with respect to the racking pin 42. Thereafter, in order to operate the lock, the same guard key must be used,
in order to engage the key-engaging portion 65 of the tumbler and cause the tumbler to be swung about post 38 in the counterclockwise direction an amount corresponding to the amount of the bend and thereby bring the gate into alignment.
In the past, the guard tumblers on safety deposit locks have had to be assembled to match the particular guard key of the installation in which they are to be used. This face prevented inventorying of completed locks by the manufacturer, since there was no advance knowledge of the shape of the particular 7 guard key which the guard tumblers would have to fit. The ordering bank had to supply that information, and only then could the locks be assembled.
The present invention overcomes that problem. The particular guard key can be fitted to pre-assembled locks, taken from inventory.
The customer tumblers must of course be matched to unique customers keys but since these are random and not specified by the bank, these tumblers can be assembled in advance as well. Thus, locks having tumblers individualized to customers keys andmodularized as to guard keys can be assembled andheld in inventory awaiting fitting to the particular banks guard key upon receipt of the order. Once the nature of the guard key is known, the locks can be fitted to that key, merely by the initial use of the guard key.
To set the lock to a particular guard key, the customer key is first inserted andtumed to withdraw the bolt. This can be done,since prior to bending the guard tumbler gates are held aligned to receive the bolt. The guard key is then inserted in a horizontal position (with reference to FIG. 4) and-turned counterclockwise 90, its limits of motion being determined by two stops 70 and 71 in the lock case-The racking pin on the. bolt, engaging in the gates, takes the reaction force of the bending. In this connection, it is desirable although not necessary, that the guard key gates have a slight lead or taper as designated at 72 which will air;- commodate slight differences in the yieldability or elasticity of the neck portion' 67 which might cause a small amount of spring back or overbending, depending on the exact grain structure of the tumbler material. When thereafter the bolt is retracted, the racking pin can cam the tumbler, within a slight range of movement, sufficiently to bring it in alignment. When the guard and customer keys are both withdrawn, the bolt will be extended and all tumblers scrambled.
It should be noted that, instead of using the bolt to hold the tumblers during this bending step, a pin (insertable perpendicularly through apertures in the tumblers) or a clamp could be employed to take the reaction force, and thereby hold the tumbler during bending. Use of the bolt for this purpose, therefore, is convenient but not necessary. It is also noted that, in order to compensate for springback in bending, it is within the scope of the inventionto hold each tumbler at a predetermined first position at which its gate is not necessarily aligned to receive the bolt, .but such that,
after bending and springback, its gate will thereafter be. correctly aligned, upon subsequent use of the key, to
(Turning the customer key tends to withdraw the bolt, and this can be done only if the guard tumblers have already been aligned, else they will block the full rotation of the customer key.) With the guard tumblers aligned, insertion and rotation of the proper customer key 34 operates on the customer tumblers to bring them in alignment and also to cause the foot or bit 45 to engage the side of the bolt slot 44 and withdraw the bolt.
The new tumblers may be employed as less than all of the guard or customer tumblers. In other words, not all of the tumblers need be of the deformable type, so long as at least one of them is. In this case, however, the number of different keys to which the new tumblers can be set is much more limited.
As previously stated, an advantage accrues even if the new tumblers are used just for the guard tumblers, since this enables locks having individualized customer keys but standardized guard tumblers, to be built for inventory, awaiting fitting to the guard keys. However, even the need to correlate customer keys and customer tumblers can be obviated by utilizing customer tumblers in accordance with the invention.
In the embodiment just described, the new tumbler has first and second stop-engaging surfaces which are distinct and separate from one another, and which become active in one-two sequence. The stop-engaging surfaces may be combined as described below, as a single surface the position of which is moved by bending. A tumbler of this type is shown in FIG. 7 and may be used either in a single key lock, or as the customer tumbler in a lock of the type described above. In this case the tumbler 74 has a single key-engaging portion, designated by 75. This comprises a bendable web or bridge, with an aperture 76 located adjacent to it in the tumbler. in this case, the portion 75 initially rests against the key post 24 which acts as a stop, and holds the tumbler gate 77 of the tumbler 74 in alignment to receive the bolt. With the bolt withdrawn and the bit engaged in the gate 77, operation of the key will deform the bendable portion 75 to the position indicated by the dotted lines in FIG. 7. Thereafter, when the bolt has been extended, this new surface will, in the rest position, hold the gate in a scrambled position. Thus, rather than a separate second stop surface which replaces the first, the position of the stop surface is changed with respect to the gate.
Having described my invention, I claim:
1. In a key lock of the lever tumbler type having spring biased lever tumblers with bolt receiving gates at the ends thereof alignable to permit a bolt to be retracted, each tumbler having a key-engaging portion which is acted upon by a key, each tumbler being biased by a spring toward stop means presented in the lock case,
the improvement comprising,
at least one lever tumbler having a bendable key-engaging portion disposed to be bent by initial rotation of the key in the lock,
stop means against which said bendable portion rests under the bias of said spring prior to bending and which positions the tumbler in a predetermined first position with respect to the bolt, and against which said tumbler rests after bending in a different second position dependent upon the shape of the key, in which second position the gate is out of alignment with the bolt,
and means for preventing rotation of the tumbler when the key is turned while the tumbler is in the first position. 2. The improvement of claim 1 wherein the bendable 5 key-engaging portion comprises an arm projecting from the tumbler which is connected to the tumbler by a yieldable neck.
3. The improvement of claim 1 wherein the bendable portion is a yieldable web adjacent an aperture in the tumbler and which is deformable by bending relative to said aperture.
4. The improvement of claim 1 wherein the stop means positions the tumbler in the first predetermined position such that the gate is in alignment to receive the bolt.
5. The improvement of claim 1 wherein the stop means includes discrete first and second stops in the lock case.
6. The improvement of claim 1 wherein the first stop is a key post.
7. In a key lock of the lever tumbler type having spring biased lever tumblers with bolt receiving gates at the ends thereof which are alignable to permit a bolt to be retracted, each tumbler having a key-engaging portion which is acted upon by a key, each tumbler being biased by a spring toward stop 'means presented in the lock case, i
the improvement comprising,
at least one lever tumbler having a bendable key-engaging portion,
the bendable portion prior to bending presenting a first stop-engaging surface which is positioned to bends it,
and a second stop-engaging surface on said tumbler that is active only after said bendable portion has been bent by said key, said second stop-engaging surface than being positioned to be arrested by the stop means in the case under the influence of said spring, in a position in which said gate is disaligned with respect to the bolt.
8. The improvement of claim 7 wherein the bendable key-engaging portion comprises an arm projecting from the tumbler which is connected to the tumbler by a neck.
9. The improvement of claim 7 wherein the bendable portion coacts with a first stop in the lock case prior to bending,
and wherein the second stop-engaging surface is not on the bendable portion of the tumbler, and is so positioned that after the bendable portion has been bent it is engageable in rest position by a second stop in the case which is spaced from the first stop.
10. The improvement of claim 9 wherein the first stop is the key post of the key which bends the bendable portion.
11. The improvement of claim 7 wherein the bendable portion, after bending, becomes the second stopengaging surface.
ing to the shape of the particular key lift whichv 12. A rotatable lever tumbler for a key'lock comprisan end portion having a gate formed therein for receiving a bolt,
means for joumalling said tumbler for rotation,
a key-engaging portion disposed for engagement with a key, said key-engaging portion being deformably connected to the remainder of the tumbler so as to be bendable to a new position by said key when the tumbler is held against rotation,
a first stop-engaging surface associated with said keyengaging portion and bendable therewith, said first stop-engaging surface prior to bending being positioned so that it can be arrested by stop means in the case and when so arrested will position said tumbler in a predetermined first position,
means engageable with the tumbler to prevent it from turning when in said first predetermined position,
and a second stop-engaging surface on said tumbler, said second stop-engaging surface positioned so that it can be arrested by said stop means to arrest said tumbler in a second position at which the gate is disaligned with respect to a bolt, after said keyengaging portion has been bent.
13. In a keylock of the lever tumbler type,
a deformable lever tumbler having an end portion with a gate formed therein for receiving a bolt,
means for joumalling said tumbler for rotation,
a key engaging portion'of said tumbler disposed for engagement with a key, said key-engaging portion being deformably connected to the remainder of the tumbler so as to be bendable to a new position by said key when the tumbler is held against rotation, 1
stop means in the case for engaging the tumbler in a rest position under bias of a spring,
the key-engaging portion prior to deformation bearing against the stop means and holding the gate in alignment to receive'the bolt,
the key-engaging portion prior to deformation being engageable with the key to be deformed by the key if the latter is rotated when the bolt is engaged with the tumbler,
the key-engaging portion subsequent to deformation bearing against the stop means after thekey is removed and holding the gate in a position of disalignment with the bolt.
14. In a key lock of the lever tumbler type having spring biased lever tumblers with a bolt receiving gates at the ends thereof alignable to permit a bolt to be retracted, each tumbler having a key-engaging surface which is acted upon by a key, each tumbler being biased by a spring toward stop means presented in the lock case,
the improvement wherein at least one of the tumblers has a key-engaging portion that is bendable by initial rotation of the key,
said key-engaging portion prior to bending resting against a stop in the case and holding the tumbler gate in alignment to receive the bolt,
said tumbler also having a portion that, when the key-engaging portion has been bent, rests against a stop in the case and holds the gate in disalignment with the bolt. 15. In a two key safety deposit box lock of the lever tumbler type having a set of customer tumblers operated by a customers key and a set of guard tumblers operated by a guard key, the tumblers having bolt receiving gates at the ends thereof which in ordinary use must be properly aligned by the respective keys to permit a bolt to be retracted, each tumbler having a key-engaging portion which is acted upon by a key, each tumbler being biased by a spring toward stop means presented in the lock case,
the improvement wherein each guard tumbler has a guard key-engaging portion which is bendable and which is positioned to be bent by the initial rotation of the guard key,
said guard key-engaging portion prior to bending resting against a guard key post and holding the tumbler gate in alignment to receive the bolt when the latter is withdrawn,
said guard tumbler also having a portion that after bending by said key rests against a customer key post and holds the gate in disalignment with the bolt.