CA1057072A - Key changeable lock - Google Patents

Abstract

Abstract of the Disclosure A double key changeable safety deposit lock includes a movable bolt and associated bolt plate including cam surfaces to be engaged and moved between open and closed positions by turning renter and guard keys in the lock, a plurality of gated tumbler renter key levers to be engaged by the renter key, a plurality of gated tumbler guard key levers to be engaged by the guard key, each of the levers being moved to align their respective gates to receive latch members on the bolt plate upon manipulation of the two keys to allow opening of the lock and wherein pivot means are provided for each lever including a plurality of individually selectable pivots such that the pivotal axis of each lever may be selectively varied to provide for different combinations of lever movement required by an associated key to align the associated gates. Releasable pivot selecting means are provided for normally engaging certain ones of the pivots of the levers which is rotatable to allow release of the lever pivots so that the levers may be moved to a new combination of positions by the insertion and manipulation of new renter and/or guard keys and then held in the new combination by re-engaging the pivot selecting means, also referred to as a fulcrum means, with the selected ones of the pivots whereby both keys for the double key lock are changeable.

Description

.1 . ' - ` , , . : -1 105707Z : - .
I . , . . ':'' 1 ¦ Background of the Invention , , ~

2 ¦ The present invention relates in general to changeable

3 ¦ key locks and more specifically to locks having one or more keys 41 for operating the lock between open and closed positions and :
~¦ wherein the internal mechanism of the lock may be selectively 6 manipulated to accommodate the use of different keys.
q Vario,us types of key çhangeable locks have been developed 8 heretofore wherein a single key is employed for turning associated :~
9 internal tumbler levers of the lock between open and closed positions. An example thereof is the prior U.S. patent No.
11 1,693,731 wherein a plurality of plate like latch members are 12 releasably secured to the bolt. A plurality of gated tumbler 13 levers are provided on fixed pivots and are moved by the key 1~ tumblers to align the gates to the aforementioned latches. The key can be changed by releasing the latches from the bolt, placing 16 a new key in the lock in engagement with the fixed pivot tumbler 17 levers in latch released relation and then re-engaging the tumbler 18 levers with the,latches to fix the combination. In another prior 19 art example, U.S. patent No. 1,268,900 a single changeable key lock is shown in association with a plurality of gated levers. The 21 levers are stated as being gated at opposite ends and pivoting 22 about a fixed axis within the lock to alternately engage primary 23 and auxiliary, separately movable bolt and auxiliary bolt members.
24 The lock constructions of the prior art, including those of the references noted, do not facilitate the provision of a 26 double changeable key lock as would be desirable for modern safety 27 deposit locks wherein both the renter and guard keys are changeablc 28 and further are not believed to present a satisfactory construction 29 ~r mode of operation for a s~ngie char.geable key lock.
It is therefore the primary object of thc present invcntion , 31 to disclose and provide a changeable key lock whcrein the lock 32 ~ ma simply and cconomically consLructcd, assembled and 1057~7Z
manipulated in use, w~lere the key can be easily changed and the lock is reliable and secure in its operation. It is also an object of the present invention to disclose and provide such a lock wherein tWD changeable keys are provided for operating the lock and the internal lock mechanism is simply and reliably manipulable for changing the combination requlred of koth keys for opening of the lock.
Generally stated, the invention provides, in a changeable key lock having a bolt, a plurality of gated tumbler levers and means for operating the bolt only when the tumbler levers æe placed in predetermdzabLe positions by manipulation of a selectable key in the lock. Pivot means are prDvided on one or more of the levers for providing a plurality of individually selectable pivots about which the associated lever may pivot whereby the pivotal axis of each such lever may be varied to provide for different comr binations of lever movements required to open the lock. Releasable fulcrum means are provided for engaging with the lever pivots to restrict each levers mDvement akout a selectable one of the pivots when engaged therewith and being releasable therefrom to allow for the selection of another of the pivots to ke engaged thereby, the fulcrum means comprising a fulcrum member and means for rotatably m~unting the member in the lock for releasing and re-engaging the pivot means through rotation of the m~mber a~out a fixed axis.
According to another aspect of the invention a double key changeable safety deposit lock comprises a moveable bolt and an associated bolt plate means provided with forward and rearward latch plates and including cam surfaoe s to ke engaged and moved between open and closed positions by turning renter and guard keys in the lock. A first plurality of gated tumbler g~ard key levers æ e adapted to be engaged by the guard key and are provided with gates alignable to one of the plates, and a second plurality of gated renter key levers are adapted to be engaged by the renter key and are provided with gates aligrable to the other one of the latch plates. The levers are maved to align their respective gates to receive the res~ective latch plates on the bolt plate to allow opening of the lock only ,:

~os7072 ,., when both keys are operated. Pivot means are prnvided on each lever for providing a plurality of individually selectable pivots, whereby the pivotal axis of each lever may be v æ ied to provide for different ccmbinations of lever mDvement require by an associated key to align the associated gates.
Releasable pivot selecting means are provided for normally engaging certain ones of the pivots of levers of koth the first and second plurality of levers ~-and are releasable to allow mDvement of the levers to a different pivot position deternined by an associated key and for re-engaging the thus aligned pivots to allow changing the combination thereof for either or koth of the guard and renter keys.
A more ccmplete understanding of the present invention, as well as a better understanding of how the present invention in key changeable lock i~proves upon the state of the art and achieves the objectives aforestated therefor will be ~rovided to those skilled in the art from a consideration of the following detailed description of a preferred exemplary e=icdiment there-of. Referen oe will be made to the appended sheets of drawings which will be briefly described prior to the detailed explanation.
Erief Description of the Drawings Fig. 1 is a perspective view of a preferred exe~plary embodiment of changeable key lock according to the present invention showing selected guard and customer keys;
Fig. 2 is a perspective view of a change key employed with the preferred exemplary emkcdiment of lock of Fig. l;
Fig. 3 is a section view of the lock of Fig. 1 taken therein along the plane III-III;
Fig. 4 i9 a front elevational view, with portion of the front face of the lock removed, taken in Fig. 3 along the vertical plane Iv-rv;
Fig. 5 is a view of the lock of Fig. 4 with the exemplary tumbler levers shown in phantom and the lock in bolt closed position;
Fig. 6 is a detail view of the lock of Fig. 5 showing the , . ,1 - . .; --- ` . :
lOS707~

1 guard key turned to open position; -2 ~ig. 7 is a view of the lock of Fig. S sXowing the ~ customer and guard keys moved to open positions and the bolt

4 withdrawn to a lock opened position;
Fig. 8 is a detail view of the loc~ of the Fig. 7 showing 6 the guard key removed and a change key inserted;
7 Fig~ 9 is a view of the lock as in Fig. 7 showing the 8 change key turned fully clockwise and the bolt fully withdrawn 9 to a change key position; ', Fig. 10 is a view of the lock as in Fig. 9 showing the 11 fulcrum means rotated to a lever release position wherein the 12 pivot means of the levers are released from the fulcrum member;
13 Fig. 11 is a view of the lock as in Fig. 10 showing the 1~ customer Xey turned fully clockwise to be withdrawn and replaced by a different customer key;
16 Fig. 12 is a view of the lock as in Fig. 11 showing a new 17 customer key turned against the associated tumblers setting them 18 in a new combination;
~9 Fig. 13 is a view of the lock as in Fig. 12 showing a new guard key inserted and turned counterclockwise against the 2~ associated levers, but prior to movement of the bolt which will 22 initially rotate the fulcrum means back into engagement with the 23 pivot means of the various levers;
2~ Fig. 14 is a view of the lock as in Fig. 13 showing the customer key turned to bolt locking position with the bolt moved 26 to its locking position preparatory to turning of the guard key 2q clockwise to a release position;
28 Fig~ 15 is a section view of the lock taken in Fig. 12 29 along the planc XV-XV;
Fig. 16 is a section view of the lock taken in Fig. 6 31 along the plane XVI-XVI;
32 Fig. 17 is a detail section view o~ thc lock takcn in Fig.
., .' . ' .

::

1 8 along the plane XVII-XVII; ~;;
2 Fig. 18 is a section view of the lock taken in Fig. 5 3 along the plane XVIII-XVIII; and 4 ~ig. 19 is an exploded perspective view, partially in section, of the lock of Figs. 1 through 18.

8 Detailed Description of the Preferred Exemplary Embo~iment 9 Referring initially to Figs. 1, 3, 4 and 19 a detailed description of the preferred exemplary embodiment in key 11 changeable lock, in accordance with the present invention, will ;
12 now be made. The preferred exemplary embodiment comprises a 1 double key changeable safety deposit lock, indicated generally at ~4 10, which may, in accordance with certain aspects of the present invention, be provided as a single changeable key lock as well.
16 The exemplary double key changeable sa~ety deposit lock, 17 indicated generally at 10, includes a housing or casing having 18 a back wall 11, top wall 12, bottom wall 13 ~Fig. 4) a latch 19 receiving end 14 having the port 15 and a closed end 16. A
conventional face plate 17 is shown secured by fasteners, preferabl 21 machine bolts, 18-21 which pass through appropriate bolt holes 22 2~-25 in face plate 17 to engage threaded ports in the casing 23 backwall, as threaded hole 24', (Fig. 19) to retain the face plate 24 within recess 26 foxmed about the opening of the casing or housing.
As is also conventional, face plate 17 is provided with key bosses 26 27 and 28, each having opposed key guide notches 29,30 and 31,32 27 respectively.
28 Referring again to Fig. l, the exemplary lock, indicated 2~ ~enerally at 10, is shown as a double key lock adapted to reccivc a customers or xenters kcy 40 and a guard key 41. As is 31 particularly contemplated within the prescnt invention, the 32 present lock is adapted to be changed to accommodate a chanqe in .` ., , -6- .c 10~707Z
both the renters and guard keys. A change key 42, as seen in Fig. 2, is employed in the key changing process as will be described hereinafter. At present, it should be noted that each of the keys has a first upper end pro-jection 43, 44 and 45, respectively with the guard key 41 having an addition-al stop or cam follower projection 46.
The renter key 40 is adapted to ke received in an otherwise conventionally journaled key guide post provided within the face plate boss 27. As kest seen in Figs. 3 and 19, a key guide post 50 is provided for receiving the renter key 40 in the key slot 51. The renter key guide post 50 has a base bearing portion 52 adapked to fit in journal aperture 34 at its lower end. Post 50 is received within a key guide journal bearing 54 which has an internal bore ter~inating in an internal non-circular portion adapted to mate with the flat 53 of post 50 to non-rotatably join the post 50 to the journal 54. Journal 54 is provided with a key slot 55 which is aligned to post key slot 51 through the provision of mating flat 53 fitting appropriately withln journal 54. The journal kearing 54, as is conventicral, is provided with a recess 56 surrounding an end face 57 adapted to fit into the opening of boss 27. A guide post cam 58 is provided adjacent the lower end of post 50 to engage and act upon portions of the bolt as hereinafter explain~d.
The guard key 41 is adapted to fit into similarily prcvided guard key guide post 60, having key slot 61, base kearing 62 and flat 63 as in the case of post 50. Post 60 mates with its associated guard key guide journal bearing 64 having key slot 65, recess 66 and end faced 67 mating with koss 28 in the same manner as descr-hc~ with regard to journal bearing 54 and boss 27. Guard post 60 is also provided with a guard post cam 68 adjacent its lower end for acting upon portions of the kolt as hereinafter explained.

- : , ~

105707Z :
. ; ':
1 Bolt means are provided in the exemplary embodiment of 2 lock including a bolt plate indicated generally at 70 and as best 3 seen in FigO 19. The exemplary bolt plate, indicated generally 4 at 70, includes a ~ody portion 71 mounting an integrally formed bolt or latch 72 extending from a shank portion 73. Body portion 6 71 has peripheral cutouts 74, 75 and 76 to provide clearance for 7 the bolts aforementioned. Latch plates 77 and 78, extending 8 laterally of body 71 as best seen in Fig. 19, are provided for 9 controlling opening movement of the bolt plate in co-operation , with the tumbler levers to be described hereinafter.
11 The bolt plate is apertured to provide surfaces co-12 operating with the guide post cams 58 and 68. A renters key 13 cam aperture 80 i5 provided in base plate body 71 as best seen 1~ in Fig. 19 with a closing cam surface 81 and an opening cam ~5 surface 82. As will be apparent to those skilled in the art, 16 rotation of renter key guide post 50 will cause the associated 17 cam 58 to alternately engage cam surfaces 81 and 82 depending 18 upon the direction of rotation of the post. A central rectangular 19 slot 85 is provided to accommodate port~ons of the fulcrum member 100, to be described hereinafter. As can also be seen in Fig. 19, 21 a guard key cam aperture 90 is provided in body 71 with a closing cam surface 91 and an opening cam surface 92 to co-operate, as 23 subsequently described, with guard ~ey post 60 and the latters 2~ cam 68.
A plurality of gated tumbler levers, indicated generally 26 at 110 and 120, are provided in accordance with the present 27 invention to be selectively and pivotally located with respcct 28 to ~ulcrum means for restricting the axis of pivotal movement 29 o~ each lever once a particular pivotal axis therefor has been selected. The ~ulcrum means therefor, as particularly contemPlatcd 31 with the prcsent invention, compriscs a fulcrum membcr 100 a5 32 best scen in Figs. 18 and 19, ~ulcrum menber 100 has a base /^ ~
1 1057~D72 :

1 ¦ bearing 101 adapted to fit within journal aperture 36. A top 2 ¦ pin or stub shaft 102 is provided on fulcrum me~ber 100 to be 31 received in the mating journal aperture 33 in face plate 17.
41 As can be seen in Fig. 18, the fulcrum member 100 is rotatably 51 mounted by its pivotal mounting in the opposed face plate and 61 rear wall of the lock housing or casing. Fulcr~m member 100 is 71 further provided with a laterally extending cam 103 which rides 8 in a cam slot 79 formed in the body 71 of the bolt plate adjacent 9 the rectangular aperture 85. A second cam portion 104 of the ,:
~0 fulcrum member is adapted to ride in the rectangular slot 85 as 11 seen in Figs. 9, 10 and 18 and has a flat side thereof 105 abutting 12 against an upper surface of slot 85 when in the lever engaging 13 position of Figs. 9 and 18, discussed more fully hereinafter. In 14 such later discussion, reference will also be made to the lever pi~ot engaging rib 106 provided along the longitudinal extent of 16 fulcrum member 100 and the xeturn cam 107.
17 As seen in Fig. 3, and as represented schematically in 18 Fig. 19, the lock of the present invention is provided with a 19 plurality of gated tumbler levers indicated generally at 110 and 120. In the exemplary embodiment, there are 7 renter key gated 21 tumbler levers, indicated generally at 110, and 7 guard key levers, 22 indicated generally at 120. Considering first and individual 23 renter key lever, all such levers being identical, and as best 24 seen in Pig. 19, the renter key lever includes an open gate 111 at its forward end having a latch stop 112 adjacent ~he gate to 26 abut against the latch plate 77 of the bolt plate when the bolt is 27 in a closed condition as seen in Fig. 4. The guard key levers, 28 indicated generally at 120, are also identical to one anothcr, 29 and as bcst s_e~ in Fig. 1~, each inciude an inwardly openins gate 121 at the free end having an inwardly facing latch stop 122 31 ad~pted to engage the latch plate 78 of bolt plate 70 as sccn in S2 F~. 4 whcn the bolt is in closed position.

.. . . . . . .. . . . .

L, `
~05707Z
. . . . ' .

1 Each of the exemplary embodiment of gated tumbler levers, 2 as is particularly contemplated within the present invention, is ;
3 provided with pivot means for providing a plurality of individually 4 selectable pivots about which the associated lever may pivot such that the pivotal axis for each such lever may be varied to provide ~ for different combinations of lever movements required to open 7 the lock. As seen in Figs. 4 and 19, each of the renter key levers 8 indicated generally at 110, ïnclude an arcuate port 113 having a 9 plurality or rac~ of saw tooth-like teeth 114 formed on an inner, surface thereof. The radius of cur~ature of arcuate slot 113 11 preferably intersects the associated gate 111 in a central portion 12 to facilitate pivotal movement of the lever about its gated 13 end during selection of one of the pivots provided by the teeth 14 114.
- The pivot means on the guard key tumbler levers, indicated 16 generally at 120, as seen in Figs. 4 and 19, comprise the provision lq of an arcuate pivot port 123 on each lever with a plurality or ~8 rack of saw tooth-like teeth 124 formed on an inner surface of 19 the arcuate 810t. The radius of curvature for slot 124 preferably 20 passes to the approximate center of gate 121 as noted hereinbefore ;
21 with regard to the renter or customer key tumbler levers indicated 22 generally at 110. It should be noted that the pivot providing 23 teeth 114 are provided on an inward side of slot 113 relative to 2~ the lever while the teeth 124 are provided on an outward side of slot 123 relative the center of the levers indicated generally at 26 120.
2~ As is particularly contemplated within the present invcntio~
28 the customer or xenter tumbler levers are provided in a first set, as b^st seen at 110 in Figs. 3 and q, in a horizontal arraY ~;th the associatcd arcuate slot 113 of each entrained upon fulcrUm Sl member 100 and the associated gatc 111 directed toward the forward 32 latch plate 77 of the bolt plate. Each such lever is providcd with . .

`' - ' :- ' .

. ~5707Z -1 an integrally formed spring arm 115 biasing the gated end to place . .. . .... .. . ... , ---- -2 latch stop 112 against latch plate 77. Each of these levers of 3 the fLrst set, indicated generally at 110, further include a 4 central tumbler port 116 providing a tumbler surface 117 to be engaged by the teeth of the renter key 40.
6 The second set of gated tumbler levers, indicated generally ~ at 120, to act with the guard key 41, and as best seen in Figs. 3 8 and 4, are placed in a horizontal array with the arcuate slot 123 9 of each entrained over the fulcrum member 100 and the associated gate 121 adjacent the rear latch plate 78, the associated latch il stop 122 of each lever abutting a rearward cornex of plate 78.
12 Each of these levers, indicated generally at 120, are also 13 provided with an integrally formed spring arm 125, tumbler port 14 126 and tumbler surface 127, the latter being engagable by teeth of the guard key when the latter is inserted in the lock.
. . . . . . ., 16 Preferably, the individual levers of the first and second 17 sets, indicated generally at 110 and 120 respectively, are 18 alternated one on the other, as best seen in Fig. 3, although 19 it is contemplated that they could be otherwise located within the lock. ~owever so located, it is important to the present invention 21 that the oppositely directed sets of tumbler levers be located 22 within the lock so that their respective pivot means, provided by 23 the teeth 114 and 124 in the exemplary embodiment, be generally 2~ aligned horizontally so that selected ones of the pivots can be engaged by the fulcrum membcr 100, and specifically rib 106 in 26 the exemplary embodiment, to releasably pivot cach of the levers 27 about selectable pivotal axis of each lever. As will be discussed 28 more fully hereina~ter during explanation of the operation of the ~n '_ck~ rotation of the fulcrum member 100 at the appropriatc ~imc will releasc each o~ the tumbler levers which will then be movcd 31 undcx the bias o~ their associatcd spring arms in a downward 32 dixection in Fig. ~ preparatory to being rcset in any dcsirCd 10~Ci707Z ll . ..
. .
1 combination thexefor through the insertion and manipulation of 2 new renter and/or guard keys as will now be described in a 4 detailed descxiption of the operation of the lock.

6 Operation of the Lock 7 The preferred exemplary embodiment of key changeable lock 8 is shown in Figs. 1 through 4 in a locked condition. During 9 normal operation of the lock to ope~ the associated safe, such ' 0 as a safety deposit box door, the renter key 40 and guard key 41 are inserted in the respective key slots 55 and 65 of key 12 posts 50 and 60. On insertion of the keys, they pass freely 13 through the tumbler apertures 116 and 126 of the two sets of 14 tum~ler levers, indicated generally at 110 and 120, respectively, which are in locking relation to the bolt latch plates 77 and 78 16 as seen in Fig. 4. This condition for the lock is illustrated 17 in Fig. 5 with the plurality of tumbler levers removed and only 18 a representative pair thereof being shown in phantom line so that 19 the co-operation between the key posts 50 and 60, fulcrum member 2 100 and the bolt plate, indicated generally at 70, can be more 21 ¦ easily observed.
22 ¦ After the renter and guard keys 40 and 41 have been insertec 23 ¦ ~nto the lock, they may bc turned clockwise to a lock open 241 position as seen in Fig. 7. Guard key 41 must be first rotated 25 ¦ ~rom the position of Fig. S in a clockwise direction to that of 26¦ Fig. 7 in order to move the guard post cam 68 away from cam 27¦ sur~ace 91 allowing ~or a withdrawal motion of the bolt plate rom 28¦ left tc ri~ht ~ ~io. ~ to ~he p~sitjon of Pig. 7. The bolt 291 platc is moved to the position of Fig. 7, a lock open conditiOn, 301 by turning the renters key 40 clockwise in Fig. 5 against cam 3~¦ surfac~ 82~ Furtllcr inward or withdrawal motion o the bolt pl~c 321 beyond thc position illustrated in Fig. 7 is prevented duc to th~
I .' ' -' `11 10571D72 1 ¦ engagement of the bolt plate against the guard post cam 68, the ;
2 ¦ guard post being held in the position of Fig. 7 due to the pro-3 ~ ~ision of the stop or cam follower projection 46 on the guard 4 ¦ key which rides in arcuate cam slot 79 as seen in Figs. 6 and

5 ¦ 16. ~ithdrawal of either of the renter or guard keys is pre-

6 ¦ vented when they are in the open position of Fig. 7 due to the ¦ presence of the end flanges of bosses 27 and 28.
. ~ ¦ The lock may be returned to a closed and locked condition g ¦ by merely closing the safe door and turning the renter and guard 0¦ keys 40 and 41 counterclockwise back to the position of Fig. 4 to 1¦ place the lock in locked condition once again. During the ~21 unlocking operation of the keys, the tumbler levers pivoted about 13¦ their selected pivots engaged against fulcrum member 100 to ;
14¦ initially align the respective gates to plates 77 and 78 as seen 15 ¦ in Fig. 7 and then to be returned out of alignment on locking of 16¦ the lock as seen in Fig. 4. .

18 ¦ Chan~e ~ ion of the Lock 19 ¦ In the event that it is desired to change the combination 20 ¦ of the lock to accommodate a new renters and/or guard key, a 1 j change key q2 coded to the existing combination of the guard 221 tumblers is inserted in place of guard key 41 in the operation 231 to open the lock hereinbefore described. Since change key 42 does 241 not have a stop projection 46, as does the guard key, it can be 251 turned past the lock open position of Fig. 7 to a key changeable 2~1 position of Fig. 9. As seen in Figs. 8 and 18, change key 42 has 27¦ its end projection 45 positioned within the guide slot 61 of post 2~1 60 but does not have a projection lying in slot 37 as did the gu~r 291 ~cy. As can be seen by a comparison of ~igs 7 and 9, thc urther 30¦ clockwise rotation of the change key moves the associated post 31¦ cam 68 against cam surface 92 of the bolt plate to movc thc lattcr 321 ~o a fully withdrawn position as illustrated in Fig. 9. ~t ~)i5 I . . .
I . ",~,,., . ., .

'`-` 'I 1057072 :

l point in the operation of the lock, the customer key is free to 21 be turned further clockwise, although it will engage against cam 31 107 before it is turned far enough to be withdrawn through the 41 guide notches 29 and 30 of the associated boss 27.
51 When the bolt plate, indicated generally at 70, has been 61 moved fully within the lock casing through manipulation of the ~1 change key 42 ~s aforedescribed, the fulcrum member 100 is manuall~
8 rotated to release the pivot means of the associated tumbler 9 levers indicated generally at 110 and 120. The base portion 101 of the fulcrum member lies within a journal aperture 36 formed in 11 the backwall 11 of the casing. A slot or hex-shaped depression 12 130 may be formed in the underside of base portion 101 which can 13 be reached from the inside of the safe door mounting the lock to 14 receive a plain or "Allen" wrench or suitable tool for manually rotating the fulcrum member 100 in a clockwise direction from 16 that shown in Pig. 9 to that shown in Fig. 10. Such rotation of 1~ the ~1crum member releases all of the associated tumbler levers 18 which are then free to move under the respective spring bias in 19 a downward direction as seen in Figs. 10 and 11 to the fully released position of ~ig. 11. The renters key 40 may be turned 21 manually to the release position of Fig. 11, or if in the position of Fig. 10 on release of the levers, may be moved to a release 2 position due to the bias of the associated levers indicated 24 generally at 110. It should be noted that rotation of fulcrum member 100 manually from inside the door is limited in a clock-26 wise direction due to the abutment of cam portion 107 against 2~ stop wall 108 ormed in the body 71 of the bolt plate.
28 Either ox both of the rentcr and guard ~eys 40 and 41 may ~3 now be replaccd. A new change key 4~' may now be inserted in thc S0 lock in place o~ change key 42. This new change key will havc 31 a codc identical to the new guard key to bc used hereina~tcr with 32 the lock. At the same timc, a new customer key 40~ may be insertec l 105707Z -1¦ in place of key 40. To reset the lock for the new keys, the 2¦ new customer key 40' is turned to an upright position, as seen 31 in Fig. 12, automatically placing each of the associated tumbler 4 levers, indicated generally at 110, in a new coded relationship 51 relative to the fulcrum member 100. Thereafter, the new change 61 key 42' may be turned counterclockwise into engagement with the ~¦ guard tumbler levers, indicated generally at 120, as seen in Fig.
81 13 to set the guard levers in a new combination or adjustment 9¦ determined by the coding of the new change key 42'. As can be 10¦ seen in Fig. 13, the tumbler levers have been raised through 11¦ the turning of the renter and guard keys to the generally vertical 12¦ positions of Fig. 13 but have not as yet been held in the new 131 combination position by engagement with the fulcrum member 100.
14¦ Re-engagement of fulcrum member-with the pivot means of 15¦ each of the renter and guard tumbler levers is automatically 16¦ accomplished on turning the new change key 42' fully upright as ~71 seen in Fig. 14 and thus rotating fulcrum member 100 covnter-18 ¦ clockwise to bring rib 106 into engagement with selected ones 19 ¦ of the pivots provided by the teeth 114 and 124 of the respective 20 ¦ levers. As can be seen from a comparison of Figs. 13 and 14, 21 ¦ movement of bolt plate 70 from the position of Fig. 13 toward 22 ¦ that of Fig. 14, to the left in Fig. 13, moves bolt plate stop 231 surface 108 against fulcrum member cam portion 107 to pivot or 24¦ rotate the fulcrum member 100 to the position of Fig. 14 and into 251 re-engagement with the pivots of the tumbler levers. A furthcr 26¦ movement of the bolt plate to the position actually illustrated 2q¦ in Fig. 14 is accomplished through turning of the renter or 28¦ customer key 40' to thc full counterclockwise position of Fig- 1~, 29¦ the associate~ post cam 5~ riding again~t cam surfac~ 8; o~ t~2 301 bolt plate to move it to thc locked position illustratcd. Thc 31¦ change key can now also be turncd counterclockwise to a rclcasc 32¦ position. The ncw matiny guard kcy may therea~ter bc cmplYCd for . . .

--~ ~
1~05707Z -opening and closing the lock in conjunction with the new renter 21 key 40~. -31 . Having thuS described the construction and mode of operatior 41 ~f a preferred exemplary embodiment of key changeable lock, and :
51 specifically a double key changeable safety deposit lock, in 6¦ accordance with the present invention, it should be appreciated q¦ by those skilled in the art that various modifications, adaptation 81 and alterations, i.e. a single key changeable lock, may be made 9¦ within the scope of the present invention which is set forth 0¦ in t e followtng claims.

223 . .

"I ,1~ '' '

Claims (8)

1. In a changeable key lock having a bolt, a plurality of gated tumbler levers and means for operating the bolt only when the tumbler levers are placed in predeterminable positions by manipulation of a selectable key in the lock, the improvement comprising the provision of:
pivot means on one or more of said levers for providing a plurality of individually selectable pivots about which the associated lever may pivot whereby the pivotal axis of each such lever may be varied to provide for different combinations of lever movements required to open the lock; and releasable fulcrum means for engaging with said lever pivots to restrict each levers movement about a selectable one of said pivots when engaged therewith and being releasable therefrom to allow for the selection of another of said pivots to be engaged thereby, wherein said fulcrum means comprises a fulcrum member and means for rotatably mounting said member in said lock for releasing and re-engaging said pivot means through rotation of said member about a fixed axis.

2. The changeable key lock of claim 1 wherein said pivot means on each such lever comprises:
a rack of saw tooth-like teeth formed on an inner surface of an arcuate slot whose radius of curvature intersects the associated lever gate.

3. The improvement in changeable key lock as in claim 1 wherein:
key activated means are provided for rotating said fulcrum member from a pivot release position to a pivot re-engagement position in response to a locking movement of the associated key.

4. The changeable key lock as in claim 3 wherein said key activated means comprises a portion of said bolt and camming means on said member for rotating said member on movement of said bolt by said key to a locking position.

5. The changeable key lock of claim 1 wherein:
said pivot means comprises a plurality of pivots formed in an arcuate slot and said fulcrum means comprises a fulcrum member extending through said slot and having a rib engaging one of said pivots.

6. The changeable key lock as in claim 1 wherein:
said bolt is provided with forward and rearward latch plates;
said gated tumbler levers are provided in a first set having gates aligned to said forward latch plate and a second set having gates aligned to said rearward latch plate whereby said levers must be operated by two changeable keys concurrently to open said lock.

7. The changeable key lock as in claim 6 wherein:
said levers and said pivot means of said first and second set of levers are provided to allow for an alignment of selected pivots of different ones of said levers in a linear array to be engaged by said fulcrum means.

8. A double key changeable safety deposit lock comprising:
a moveable bolt and an associated bolt plate means provided with forward and rearward latch plates and including cam surfaces to be engaged and moved between open and closed positions by turning renter and guard keys in said lock, a first plurality of gated tumbler guard key levers to be engaged by said guard key and having gates alignable to one of said plates and a second plurality of gated renter key levers to be engaged by said renter key and having gates alignable to the other one of said latch plates, said levers being moved to align their respective gates to receive the respective latch plates on said bolt plate to allow opening said lock only when both said keys are operated;
pivot means on each lever for providing a plurality of individually selectable pivots whereby the pivotal axis of each lever may be varied to provide for different combinations of lever movement required by an associated key to align the associated gates;
and releasable pivot selecting means for normally engaging certain ones of said pviots, of levers of both said first and second plurality of levers and being releasable to allow movement of said levers to a different pivot position determined by an associated key and for re-engaging the thus aligned pivots to allow changing the combination thereof for either or both of said guard and renter keys.