CA1152767A - Cylinder locks - Google Patents

Abstract

ABSTRACT
The invention is concerned with cylinder locks of the kind in which one or more tumblers provide obstruction to rotation of a barrel of the tumbler mechanism of the lock, and a key inserted into the tumbler mechanism engages with the one or more tumblers to withdraw them from providing such obstruction by initial turning of the key in one direction from its position of insertion so as thereby to enable further turning of the key in that same direction to effect unlocking.

Description

1152~67 This invention relates to cylinder locks.

The invention i9 particularly concerned with cylinder locks of the kind in which one or more tumblers provide obstruction to rotation of a barrel of the tumbler mechanism of the lock, and a key inserted into the tumbler mechanism engages with the one or more tumblers to withdraw them from providing such obstruction by initial turning of the key in one direction from its position of insertion so as thereby to enable further turning of the key in that same direction to effect unlocking.

Cylinder locks of the above specified kind are described in United Kingdom Patent Specification Nos 737,547 and 1,030,921, and have been utilized extensively and very successfully in diverse applications. Such locks offer a ; high degree of security and are especially resistant to picking. However certain characteristics of such locks, which whilst advantageous in these and other respects, have tended to limit their more general application. In particular the fact that tumbler withdrawal takes place only in response to the initial turning of the inserted key (rather than as with other more-widely known cylinder locks using spring-loaded tumblers, merely upon key-insertion) has precluded their application incircumstances where turning of the key in either of two direction~ from the position of insertion is desired for lock operation.

Such circumstances arise, for example, with locks of motor-vehicle doors where, conventionally, the step of unlocking the door involves insertion of the key, 3~

~15Z767 turning it in one direction from the position of insertion and then returning it to the position of insertion for withdraval, whereas the step of locking requires precisely the same procedure except that the direction of turning from the position of insertion is opposite to that required for unlocking. Known forms of lock of the said specified kind are incapa~le of practical application in such circumstances. More particularly with known forms of such locks, tumbler withdrawal occurs only in response ~o initial turning of the key in one direction from the position of insertion, and turning of the key in the opposite direction to return it to its position of insertion prior to withdrawal of the key, extends the tumblers to project from the barrel and obstruct rotational ; freedom of the barrel once again. Turning of the key from the ~; position of key insertion, in this same, opposite direction is also hlocked by the projecting tumblers, and indeed attempt to turn the key in this direction from such position merely establishes the obstructing projection of the tumblers more firmly.
It is one of the objects of the present invention to provide a lock of the said specified kind that may be used to overcome the ahove-mentioned limitation of known forms of lock of this kind.
In accordance with one aspect, the invention is a key-`t operable cylinder lock in which tumblers act to obstruct rotation of a barrel of a tumbler mechanism of the lock, and a key inserted into the tumbler mechanism engages with the tumblers to withdraw them by initial turning of the key in one direction from its position of insertion so as thereby to enable further turning of ~ the key in that same direction to effect unlocking, the improvement .' ~'- .
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' ~ ' ll~;Z767 wherein the tumbers act to obstruct rotation of the barrel in the said one, unlocking, direction only, the barrel being free from obstruction for rotation in the opposite, locking direction from the position of key insertion without withdrawal of the tumblers, and spring means opposes resiliently rotation of the tumbler mechanism with ~he key in the locking direction from the position of key insertion.
In accordance with another aspect, the invention is a key-operable cylinder lock responsive to turning of an inserted key in opposite directions from its position of insertion to effect locking and unlocking actions respectively of the lock, comprising: a tumbler mechanism receiving the inserted key in operative engagement for turning in the locking and unlocking directions with the key, the tumbler mechanism comprising a barrel mounted for rotation in the locking and unlocking directions from the said key-insertion position, and withdrawable tumber means carried by said barrel to obstruct rotation of the barrel from said key-insertion position in said unlocking direction only, said tumbler means engaging with said inserted key to respond to turn-ing of the key in the said unlocking direction, said tumblermechanism including means providing rotational slip ~etween the barrel and the inserted key through initial turning of the inserted key in said unlocking direction from the key-insertion position, and said tumbler means responding to the initial turning of the inserted key in said unlocking direction from said key-insertion position to withdraw from obstructing rotation of the barrel in that direction; and further means opposing rotation of the said tumbler mechanism in the said locking direction from said key-", ~lS2767 insertion position, said further means including spring meansengaging with said mechanism to oppose resiliently rotation of said mechanism in at least said locking direction from said key-insertion position.
With the cylinder lock of the present invention the one or more tumblers are used for obstructing rotation in the one, unlocking, direction only. The spring means may simply be a coiled spring, and one or more further tumblers may be carried by a further barrel of ~he tumhler mechanism for obstructing rotation in the said locking direction until there is withdrawal of these one or more further tumblers by the inserted key. Where two barrels are provided they may be intercoupled with one another in the tumbler mechanism via a lost-motion coupling that is pro-vided simply by a lug that projects from one of the barrels and engages in a slot of the other. The further barrel, moreover, may have a rearwardly-extending lug that is engaged by the spring means so as to provide resilient opposition to rotation of both barrels in both the locking and unlocking directions from the position of key insertion.
A lost-motion coupling may be incorporated into the mechanism between the first-mentioned barrel and a part which defines a keyhole to the forend of the lock and which turns with the inserted key. Such coupling may be arranged to allow slip between the barrel and the keyhole-defining part for turning of the keyhole-defining part through a limited angle in the unlocking direction from the position of key insertion.

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A cylindes: lock in accordance with the present invention will now be descri~ed, by way of example, with reference to the accompanyi.ng drawings, in which:-5 Figure 1 is a view of the cylinder lock fxom - its forend;

Figure 2 is a sectional side-elevation of - the lock taken on the line II-II
of Figure l;

Figure 3 is a plan view of the lock;

Figures 4 and 5 are end elevations of the lock, with and without, respectively, an operating lever;

Figures 6 and 7 are sectional end views of the lock taken on the lines YI-VI
and VII-VII respectively of Figure 2;

Figure 8 is an exploded view of the lock;

25 Figure 9 shows at ~a) and (b) forend and rear views of a casing of the lock;
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~igure 10 shows at (a) to (c) front, side and 30. sectional-side views of a disc- .
insert that is located to the forend of the casing of Flgure 9 in the .e_hs~lsm of the 1Ock;

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- ~S2767 Fiyure 11 shows at (a~ to (c) front, side and rear views of a bush that engages with the di.sc-insert of Figure 1 in the lock mechanism;

Figure 1~ shows at (a) and (b) front and side views of a disc that engages with the bush of Figure 11 in the lock mechanism;
Figure 13 shows at (a) to (d) front, rear, side and sectional-side views of one of two barrels forming part of the lock mechanism;
Figure 14 shows at (a) to (d~ side views and front and rear views of the other barrei of the.lock mechznism; and 20 Figure lS sho~7s at (a~ to (d) front, rear, siae and plan views of a cover that serves to close the casing of . Figure 9, in the lock.

25 The lock illustrated in the accompanying drawings will be described in the context of its application to the locking of a door of a motor vehicle. In such application the locking of the door re~uires insertion of an appropriate key into the~lock, turning of the key in one direction and then back to return i~ to the insertion position before withdrawal, whereas unlocking requires insertion of t~e key, turning in the opposite direction ~rom that.used for locking and then tuxning it back again ~o the insertion po.sition ~e~ore withdrawal.

~e~erring to Figure~. 1 to 8, the key-operable tum~ler mechanism 1 of the lock is con~a~ned ~ithin a cylindrical .
, . . llSZ767 _ 6 die-cast c~sing 2 - shown in detail in Figure 9 that has a flange 3 located at the ~orend of the lock. The flange 3, which is for use in c]amping the loc~ in the vehicle door and which has a central aperture 4, provides an escutcheon for entry of the key 5 ~Figure 8) to a keyhole 6 of the mechanism 1 within the casing 2. A
spindle 7 of the mechanism 1 projects through a cover 8 that closes the rear-end of the casing 2, and carries a lever ~ for coupling to the door latch (not shown). Until the appropriate ~sey 5 is inserted in the keyhole 6 and turned, the mechanism l as a ~7hole, is restrained from turning within the casing 2. However when the appropriate key S is inserted and turned, the mechanism 1 is freed to turn with the key through a substantial angle in either direction from the position of key insertion. The spindle 7 and lever 9 turn with the mechanism 1, and the door latch is résponsive to the deflection of the lever 9 to lock or unlock the door according to the sense of the aeflection.
In the present case,-clockwise rotation of the key - as viewed from the forend of the lock - is requlred to unlock the door, whereas counter-clockwise rotation is required ' tb lock it. The lever 9 turns back upon return of the key to the key-insertion posit~on for withd~awal, but the latch mechanism is unresponsive to this return movement, leaving the door locked or unlocked until the ~ey is again inserted in the keyhole 6 and turned in the clockwise or counter-clo~kwise sense, respectively.
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The keyhole 6 is defined by a rectangular slot 10 in a disc-insert 11 - shown ~n detail in Figure 10 - that is located within the casing 2 and is seated within the ap~rture 4. A spring-biased shutter 12 closes the keyhole 6 behirld the slot 10, the shutter 12 being pivoted on a spindle 13 and biased b~ a spring 14 to cover the slot 10 The ends of the spindle 13 are trapped within slots 15 in a bush 16 ~ shown in detail in Fi~ure 11 -; that abuts the insert 11, so that under the thrust of the ~, . ~ .. . . .

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` ` 115Z767 key 5 entering the keyhole 6, the shutter 12 pivots backinto the bush 16 on the spindle 13 against the bias of the spring 14.

S The bush 16 has two forwardly-projecting lugs 17 that engage tightly with slots 18 in the periphery of the insert 11, . ,and two rearwardly-projecting lugs 19 that similarly ,~ . engage with slots 20 in the periphery of a slotted disc 21 -,~ sho~n'in detail in Figure i2 - that abuts the rear of the ~' 10 bush'16 in the assembly. The insert 11, bush 16 and , : .disc 21 intercoupled in this'way are free to rotate as one together within the casing.2 except to the extent that such ::. turning is limi;ted by a lug 22 that projects forwardly , ~ :from a~cup-shape barrel 23 - shown:in detail in Figure 13 -I5 into a lar~e slot 24 having flanks 25 and 26,in the periphery 1~ ~of the~disc 21~. ~The'lug 22 normally ~abuts the flank 25;ofn the slot 24 80 ~as to urge'the barrel 23 to:turn with the .,1 'intercoupled insert ll,'~bush 16 and disc 21 in the counter-~' ' ' clockwi,se sense;'the intercoupled insert 11, bush~16 and ":~! ' 20 disc 21 may however rotate to a substantial extent in the , ~opposlte, clockwise sense free of the barrel 23. .
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~ : The barrel 23 contains a pack of six tumblers 30 .(of which ,,l . ' ~ only two are shown in Figure:8) that are:separated one from ', 25 :the:other by five washers 31 ~of:which only one is shown 'ln Figure 8l~ and are,urged tightly together and onto the' rear,:of $he disc 21 by a dished spring-washer 32. Each tu.mbler:30 ~has two arms:33 that extend in opposite I directions to one another'from an apertured bellied-30 ~portion 34.into two slots 35 respectively in the cylindrical , . , wall o~ the barrel 23. The inside conf1guration of this wall~(see ~a). of~Figure 13 especially) is such as,to enable '.each tumbler 30 freedom to move transversely of the ', ' barrel.23 with its arms 3~ sliding ~n the slots 3~ (see '.' 35~ Figure 6). The.overall width of each tumbler 3~ measured .. across- the arms 33::equals the external diameter of the ~'"~ barre1:~23~ and accordlng t'o the transverse loca~ion of the . - :
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individual tumbl~r 30 within the barrel 23, so either it i5 withdra~ to be contained who].ly within the compass of the barrel 23, or one or the other of its two arms 33 projects.
It is only when all six tumblers 30 are withdrawn into the baxrel 23 so that none of the arms 33 projects therefrom, that the barrel 23 is freed for turning in the clockwise sense; turning of the barrel 23 in this sense is otherwise obstructed, (as illustrated in Figure 6), by abutment of those of the arms 33 that project (in either direction) ~' 10 from the ~arrel 23, with shoulders 36 within the cylindrical ' casing 2.

~ The.barrel 23 is free to turn in the counter-clockwise ~ sense w.ithin the casing 2 whether or not any of the arms 33 ~ . 15 project, except to the extent that such turning is xestrained by a second barrel 37 - shown in detail in Figure'~.4 - that incorporates the rearwardly-projecting , spindle 7.. In this respect, the barrel 23 has a rearwardly-: , extending lug 38,that ls engaged with a slot 39 in the , 20, barrel.37, the angular extent of the slot 39 between its ', flanks' 40 and 41 being such as to allow twenty degrees of ~' slip or lost motion in rotation between the two barrels 23 ' and 37. The barrel 37 is biased - under the action of a : coiled'spring 42 mounted externally of the casing 2 - into ' 25 the condition in which the flank 40 normally abuts the '. ' Iug 38. In this condition the lost-motion intercoupling of the barrels 23 and 37 enables the barrel 23 to turn , through twen,ty aegrees in the.counter-clockwise sense ' ~ independently of the barrel 37, or the barrel.37 to turn .,'' 30 through twenty degrees i.n the clockwise sense independently ,. of the barrel 23, before the lug 38 abuts the flank 41.
', . The barrel 37 is howe~er itself free to turn in the courlter-clockwise sense against the bias of the spring 42, ~ ' in dependence:upon the transverse location therein of a ,, 35 single tumbler 4~.

'. , . The tumbler 43, like the t~mblers 30, has two arms 44 that ~ :

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:. ' .. ' ~ '., : . ~ , -, ,,, -` 1152767 g extend in opposite d~rections to one another ~rom an apertured bellied-portion 45. The two arms 44 extend into two s].ots 46 respectively in a cylindrical portion 47 of the barrel 37, and the inside confi.guration of the portion 47 tsee ~c) of Figure 14 especially) is such as ~, to enable the tumbler 43 to move transversely of the barrel 37 with the arms 44 sliding in the slots 46 (see ., Figure 7). The overall width of the tumbler 43 across the : ~ arms,44 is equal to the extexnal diameter of the portion 47, ' 10 and according to the transverse location of the tumbler 43 within the barrel 37, so either it is withdrawn to be ~, ~ .contained wholly within the compass of the portion 47, or ,' . one.or the other of its arms 44 projects transversely from it~ It is only when the tumbler 43 is withdrawn that the ~; 15 barrel 37 is freed for,turniny in~the counter-clockwise sense; such turning i8 .otherwise obstructèd, as illustrated in Figure 7, by the projection of:one~or the other of the arms 44 f~rom the:barrel 37 to abut,with one or the other of two sh~Dulders 48 that project forwardly~wlthin the casing 2 ~,, 20 from the cover 8 - shown; in detail in Figure 15. ., ' .
~ The cover ~, whlch is clamped to the casing 2 by screws 49, '¦~, .. is pierced.by an arcuate slot 50 of almost semicirçular extent, coaxial with the spindle 7. It is through this 25 '~lot'50 that a rearwardly-extending lug 51 ~see (b) and ,'(d) of Figure 14 especially).of the barrel 37 p-ojects to :be~engaged by the coiled.spring 42 and make driving `engagement with the lever 9, externally of the casing 2.
:The~,spring 42~ embraces the:spindle 7 and its two ends 52 30~ are crossed to extend on either side of the lug 51 and ' engage with a rearwardly-extending lug 53 located on the~
,, cover~8 mid-way round the.slot 50. ~hus turning of the barrel 37 in~ either;sense with1n.the casing 2 to deflect he lever,9, is opposed resiliently by the engagement of ,' i ~ : ~ . . . .
35: the lug 51 with.one or other end 52 of the spring 42 to restore th'e barrel 37/ and with it the lever 9, to its ~, ,"."' normal angular positlon.

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llS2767 ~ 10 -Insertiol1 o the key 5 in the lock engages it in the apertures 5~ of the tumblers 30 and also in the aperture 55 of the tumbler 43~ When the apertures 54 and 55 are in register with one another appropriately to receive the key, the t~nblers 30 and 43 are then all positively located ; to obstruct rotation, that is to say, one or other of the arms 33 of each tumbler 30 and one or other of the arms 44 of the tumbler 43, project from the respective barrels 23 and 37L Withdrawal of the tumblers 30 or of the tumbler 43 takes place only in response to tuxning of the key 5 from 'its position of insertion in, respectively, the clockwise or counter-clockwise sense to unlock or lock the do~r.

The intercoupled insert ll, bush 16 and disc 21 turn freely ],5 with the key 5 within the casing 2. If the key is turned ' ~rom its position of insertion in the clockwise sense (to , , unlock the door), the initial turning is not followed by . the barrel 23 since clockwise turning of ~he barrel 23 is obstructed by the abutment of the tumblers 30 wi~h the , 20 shoulders 36 of the casing 2. Turning of.the barrel 37 in ', this sénse;is not however obstructed by the tumbler 43, and . . . the engagement of the key within the aperture 55 of the tumbler 43 turns the barrel 37 with the key against the bias , of the spring 42. As the key turns therefore, so contact ~; 25 of the iugs 38 and 22 of the barrel 23 with the slot-', flanks 40 and 25 of the barrel 37 and disc 21 respectively, , is broken leaving the barrel 23'stationary.

:, Engagement of the clockwise-turning key within the ' 30 apertures 54 of the tumblers 30 acts to.displace them ,', . transversely within the barrel 23. Provided the cut of the ,~ key is appropriately-related to the aperture-configuration -, in each case, all tumblers 30 are withdrawn together into the barrel 23 in response to some twenty degrees, or less, 35. of inltial ~urnin~ of the key from its position.of , insertionL Thus after the:initial turning of ~he key, the barrel 23 becomes free to turn with the key and the rest '~; ' ' ` -.
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115;~767 o the mechanism 1. Turning of the key to the full extent to rotate the mechanism 1 and provide the clockwise deflection necessary to operate the door latch to unlock the door, can therefore be achieved in this case. On the other hand, the full extent of rotation in this respect i5 not possible if the wrong cut of key is used since the tumblers 30 are not then all withdrawn, and turning of the barrel 23 accordingly remains obstructed. After the initial turning of the key, further turning in the clockwise sense is in this case obstructed by abutment of the slot-flank 26 of the disc 21 with the lug 22 of the stationary barrel 23, and ab~utment also of the slot-flank 41 of the barrel 37 with the lug 38.

, When the key is turned from ~ts insertion position in the counter-clockwise sense (to lock the door), the barrel 23 in this case turns with it, and it is rotation of the -barxel 37 that is obstructed by abutment of the tun~ler 43 with one or other of the shoulders 48 of the cover 8.
Abutment between the lug 38 and the slot-flank 40 is broken by the turning of the barrel 23, and the engagement -~f of the key within the aperture 55 of the tumbler 43 displaces the tumbler 43 transversely with respect to the barrel 37.
Provided the key is correctly cut with respect to its aperture-configuration, the tumbler ~3 is withdrawn in response to turning of the key through twenty degrees, or less, from its insertion position. Once the tumbler 43 is wlthdrawn, the barrel 37 is free to turn with the key and the rest of the mechanism 1 in the counter-clockwise sense against the hias of the spring 42. The ~ey can accordingly then be turned on to the full extent in the counter-clockwise sense to provide the deflection of the lever 9 necessary to lock the door. If, on the other hand, the cut of the key is incorrectly xelated to the aperture 55 of the tumhler 43, the tw~ler 43 is not withdrawn and continues to obstruct turning of the barrel 37~. This , .
~ ~ eventually obstructs fulI turning of the key and the rest , ".~ , .

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`." : ~ .' -' ~ - , - 12._ o~ the mech~ni.sm l by ahutment of the lug 38 of the barrel 23 with the slot-flank 41 of the stationary barrel 37.

Turni.ng back of the key to i~s insertion position for withdrawal following either clockw~se or counter~clockwise - turning, restores the lock mechanism l to its initial condition. In particular, the engagement of the key within the apertures 54 of the tumblers 30 during return from clockwise turning, displaces the tumblers 30 transversely -to project once again from the barrel 23 and obstruct clockwise turning. Similarly, engagement of the key within the aperture 55 of the tumbler 43 during return from counter-clockwise turning, displaces the tumbler 43 transversely to project from the barrel 37 to o~struct counter-clockwise turning once again.

The tumblers 30 and 43 and the key.5 are constructed in ~ accordance with the principles described in U~ Patent ; 20 Specification No. l,030,92l, to provide different lock comhinations or differs. It will be appreciated in this - respect also that the number of differs can be changed by use of different numbers o~ tumblers with the barrels 23 and 37, from those described; i.n particular more than one tu~bler may be used with the barrel 37.
:, ' With the lock described above, the spindle 7 (being integral with the barre.l 37) aoes not rotate during initial turning of the key in the counter-clockwise (locking) sense; when turning is in the clockwise (unlo~king) sense, on the other hand, it turns with the key through the initial, limited angular range of freedom from the insertion position.
This latter llmited turning of the spindle 7 and consequent / deflection of the ~ëver 9 (retained on it by a spring S 35 clip 56 and engaged by the lug 51), is in general of no 'l disadvarltage in relation to lock security. Un~ocking ~ operation of the door latch in ~he present instance requires : :

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. ! , : ' ` llSZ767 defl.ecti.ol, of the lever 9 through a much larger angle than involved in this initial freedom, but if this were not the case the lock could be readily modified to avoid it in the unlocking sense. More especially the barrels that are operative for unlocking ~23) and locking (37) Inay be inter-changed with one another so that the spindle 7 is then directly connected to the unlocking barrel rather than as in the above-described example, to the locking barrel.

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Claims (5)

I claim:

1. In a key-operable cylinder lock in which tumblers act to obstruct rotation of a barrel of a tumbler mechanism of the lock, and a key inserted into the tumbler mechanism engages with the tumblers to withdraw them by initial turning of the key in one direction from its position of insertion so as thereby to enable further turning of the key in that same direction to effect unlocking, the improvement wherein the tumblers act to obstruct rotation of the barrel in the said one, unlocking, direction only, the barrel being free from obstruction for rotation in the opposite, locking direction from the position of key insertion without withdrawal of the tumblers, and spring means opposes resliently rotation of the tumbler mechanism with the key in the locking direction from the position of key insertion.

2. A lock according to Claim 1 including rotatable means defining a keyhole for receiving the inserted key and turning therewith, and lost-motion coupling means intercoupling the said keyhole-defining means with the barrel to enable the said keyhole-defining means to rotate with the key relative to the barrel during said initial turning of the key.

3. A lock according to Claim 2 or Claim 3 wherein said spring means is a coiled spring engaging said tumbler mechanism.

4. A key-operable cylinder lock responsive to turning of an inserted key in opposite directions from its position of insertion to effect locking and unlocking actions respectively of the lock, comprising: a tumbler mechanism receiving the inserted key in operative engagement for turning in the locking and unlocking directions with the key, the tumbler mechanism comprising a barrel mounted for rotation in the locking and unlocking directions from the said key-insertion position, and withdrawable tumbler means carried by said barrel to obstruct rotation of the barrel from said key-insertion position in said unlocking direction only, said tumbler means engaging with said inserted key to respond to turning of the key in the said unlocking direction, said tumbler mechanism including means providing rotational slip between the barrel and the inserted key through initial turning of the inserted key in said unlocking-direction from the key-insertion position, and said tumbler means responding to the initial turning of the inserted key in said unlocking direction from said key-insertion position to withdraw from obstructing rotation of the barrel in that direction; and further means opposing rotation of the said tumbler mechanism in the said locking direction from said key-insertion position, said further means including spring means engaging with said mechanism to oppose resiliently rotation of said mechanism in at least said locking direction from said key-insertion position.

5. A key-operable lock according to Claim 4 wherein said spring means comprises a coiled spring engaging said tumbler mechanism to oppose resiliently rotation of said mechanism in both said locking and unlocking directions from said key-insertion position.