US2390471A - Cylinder lock - Google Patents

Description

A. SUTER CYLINDER LOCK Filed Marbh 2a, 1944` Patented Dec. 4, 1945 CYLINDER Loox Alexander Suter, Basel, Switzerland, assignorvto Spiku-Trust, Vaduz, Liechtenstein, a corporation of Liechtenstein Application March 28, 1944, Serial No. 528,377 -InSwitzerland J anuary 30, 1943 4 Claims.

(Cl. 'l0-385) The present invention refers to changeable combination cylinder locks and keys therefor.

Insuch` locks ythe key can be introduced into `the lock, or withdrawn from the lock, in three positions, namely the locked position, the open `position and the intermediate position (neutral n'position) `thelock maybe set to a new combination by the insertion of a key with a diiferent combination In neutral'position, the tumblers of of the pegs of thekey-bit. Thereafter the lock will react to this new key and it will no longer be possible to'operate it by means of the original key. '1 Such locks areconveniently provided with one master key and a certain number of standard keys in which the pegs are not'adjustable, for

wwhich', however, the required number of pegs in various lengths is available for fitting to these keys. In other Words, the standard keys can be fitted with the required pegs in a combination `corresponding to that of` the master key. The 14master key is equipped with bit pegs provided with a scale, so that' the pegs may be set according to any pre-selected figure, for instance six key pegs *set to a six gure number. Itwill be advisable to lkeep the master key under lock and key and to use for locking and unlocking a certain number of standard keys set in accordance with the master key. Of course, the consequence of any modication ofthe master key is to render necessaryzthe `re-setting of all the standard keys; it

follows'jas a matter of course that thesetting of the master key should be modified as seldom as possible and only in case of need.

\ The present invention aims at such a design of the lock and of the corresponding keys as shall insure that, in neutral lock position. it shall be `impossible to withdraw the standard key from, o-r

' re-insert it into, the lock and that even for the master key this shall be possible under certain conditions only. "The invention is characterised by the feature that at least one locking organ-which can be released or disconnected-is provided for preventing the unintentional withdrawal of the keys out of the neutral lock position, and that the bit of Vthe master key, as compared with the bit of the Figure l is a section along the line V|"l of Figure 2, showing the lock in neutral position.

Figure 2 is a longitudinal section along the broken line 2 2 of Figure 1. i

Figure 3 shows the grouping of the key locking organs, the lock being in open position.

Figure 4 is a fragmentaryl detail off `Figure 3. l Figure 5 is a front elevation of the lock Vin locked position. 'y f Figure 6 is the key slot in neutral position.:V Figure 7 is the same, with the locking organ released. l

Figures 8 and 9 areA end and sideelevatiolls respectively of the bit of themaster'key.

Figures 10` and 11 are end and side elevations respectively of the bit of the Vstandardkey.

Theho-using l isprovided with six dovetailshaped grooves 2 in which the serrated dovetails. 3 are axially slidable. In the housing I is lodgeda cylinder 4 provided withA six dovetail'fshaped grooves 5 also extending axially.V To each of these grooves 5 corresponds a hole 6 and a slot 1.1 T- shaped slides are housed in the grooves; ,they are constituted by the dovetail-shaped piecerl, the connection 9 and the bolt I0. The springsl Il inserted in the holes 6 maintain the slidesin the neutral position shown in Fig. 2. The slides, .in their part 8, are provided with noses l2 reaching l over the ends of the dovetails 3. When inserting the key into the slot `I3 the bit pegs I4 displace the slides rearwardly, each slide according to the setting. of the respective peg. Through the`v subsequent turning ofthe key, and thus of the cylinder 4, the serrations I5 of the `cylinder 4 `engage the serrations of the dovetails 3, so that these latter are locked axially in their shifted position. The noses l2 of the slides are simultaneously disengaged from the dovetails V3. so that the slides are forced back into their initial position by the pressure of the springs l I, locking the lock. The cylinder can only be turned back byla key provided with a bit exhibiting the same Deg combination as the key` by which the slides Were dovetails 3 now catchinto the. adjacent serra.

tions I5' which lock the dovetails 3 in the open position. Between these two cylinder positions there is an intermediate position as shown in Figs. 1 and 2, the neutral position, in which the grooved bodies 3 are resting between the noses with the result that theprevious' key' willE notl fit any more. Should therefore a keyv be unintentionally withdrawn while the lock is in neutral position, the lock couldV be opened and locked byany other key and the possessor of the first key would be unable to open his lock an more.

In order to eliminate this danger, they keys-as shown in Figs. 8-11-are provided with grooves I6 accommodating locking organs I'I, I 8. Of these locking organs the lock plates', I.'I are xedrto the housing I by the pins I9 and extend' into thek groove of the cylinder 4. These lock plates are provided with recesses 2I which in the open;`v

-lock position corresponds to the key slot I3. The

locking discs I8 of the locking organs are' rotatably mounted: in the groove 20' of the cylinder 4. These are pressed.v by the. noses 23 of thecover disc 24 by means of the spring 25, against the locking plates IT (see Eigsb and 4). The locking discs I'8` are provided with recessesy 26 which enable the key to be withdrawn from the lock i'n locked' position. The bars' 22 and 22 ofy the cover disc 24 are carried through slots 2'I of the housing I; andthe cover disc 24 is rotatably positioned on the housing I by means of the snap ring `28. The bar 22 is provided. with a perforation Pinto which one endof theV spring 25 is hooked. The other endl of the spring 25` is hooked in the bolt 29 xed on the housing. I. 8.) The cover disc 24' is provided with utes 38, so that it can be turnedv by hand against the spring pull'. The lock plates I1 are provided with recesses 3I' defining corners 33 corresponding to the. recesses 32 of the master key, Figs. 8 and 9.

' Iigr 6; shows the key slot I 3' in neutral position. The corners 33 of the locking plate I'I and the corners 34 of the locking discsI I8 occupy the extreme' ends of' the key slot I3 and engage the v grooves I6" of the key, with the result that, al-

though the key may be' turnedV it cannot be withdrawn from the lock in this position. If it isv desiredA to change the lock to another combination of.' the bit pegs, the master key (Figs. 8 and 9) is inserted into the lock and turned until th neutral position is reached.

.By turning the cover disc 24 the locking discs I8 are shifted so that their corners 34 move out of the range of the key slot I 3'. The master key can now be withdrawn and' altered at will because of its' recess 32 corresponding to the corner 33 which permanently occupies the position shown in4 Figures 6 and '7. The lock remains in neutral position until the modified master key is again inserted into the lock. In order to make it impossible that in the interval another key besides the master key shall be inserted into the lock, the recess' 32 of the master key is not to be found in the standard keys. There ,is thus no possibility whatsoever to insert a standard key into the lock in neutral' position, or to withdrawl it. Thus there is an absolute guarantee that the lock cannot be tampered with by third parties. whether by mistake or intentionally. `According to the nature of theV invention, the locking of the key-hole in (See Figs. 2 and tion, all of which variations and modifications are to be included within the scope of the present invention.

Iv claim;

A changeable combination cylinder lock comprising,` in combination with a housing, a Y

cylinder rotatable in said housing between a locked, an unlocked and a neutral position, said cylinder being formed with a key slot, anda master key and standard keys adapted to operate said lock. said standard keys having a cross section adapted to occupy substantially all of said key slot, a circumferential groove Vformed in saidcylinder, a recess formed'y in said keys axially coincident with said groove, a locking y plate xedly mounted in said housing and'V having a portion extendinginto portions of said groove and said recess and occupying a part of said key slot in the neutral position of said' cylinder, and a recess formed in said master key'corresponding to said slot-occupying portion.

2. In a lock according to claim I,`a lockingi disc rotatably'mounted in saidv groove and. having a portion adapted by rotation of said disc-tov occupy and to-'move out of another part/.of said key slot in the neutral position off said cylinder..

3. In a lock according to claim 1', a locking.l disc rotatably mounted in said groove and having4 a portion adapted by rotationv of said disc to occupy and to move out of another part of said key slot in thel neutral position of.' said cylinder, av spring actuating said discinto occupying position and external means for! rotating saidl disc: out: of; said position.

4. A changeable combination. cylinder lock comprising, in combination with a housing', a

cylinder rotatable inA said housing between a locked, an unlocked and a neutrali position, said cylinder being formed with a key slot, and a master key and standard keys adapted' tov operate said lock,` said standardkeys having a cross section adapted to occupy substantially all Yof said key slot, a circumferential groove formed in said cylinder, a recess formed in said keys7 axially coincident with said groove, ailocking plate xedly mounted in said housingV and having a portionk extending into portions of said groove and seid recess and occupying a part of said key slot in the neutral positionof said cylinder, a recess formed in said master key corresponding to said slotoccupying portion, a locking disc rotatably.

mounted in said groove and having a portion adapted by rotation of saiddisc to occupy and to move out of another part of said slot in the neutral position of said cylinder. a spring actuating said disc into occupying position and a cover disc rotatably mounted on said housing and adapted to rotate said kdisc out of said slot occupying position.

ALEXANDER SUTER.

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