CA1150524A

CA1150524A - Electronically coded cylinder lock and key

Info

Publication number: CA1150524A
Application number: CA000323761A
Authority: CA
Inventors: Peter Rutimann; Rolf Bruhin
Original assignee: Bauer Kaba AG
Current assignee: Dormakaba Schweiz AG
Priority date: 1978-03-29
Filing date: 1979-03-19
Publication date: 1983-07-26
Also published as: ATA174079A; SE7902397L; IL56891A0; AU4535079A; AU519693B2; CH627513A5; AT361798B; JPS54134000A; GB2018347B; BE875155A; SE429248B; IT1111268B; DE2818730A1; NL7902029A; ES478729A1; MX148211A; DK126179A; GB2018347A; NO791011L; BR7901895A

Abstract

ABSTRACT OF THE DISCLOSURE
In order to determine the identity and authorization of a key which is inserted into a cylinder lick, the key is provided with an information carrier with elements which are magnetically passive and inductively readable and yield permanently stored information, The carrier is fixed to key blade. A reading head mounted in the lock reads the carrier as the key is moved into or out of the lock, An electronic evaluation circuit uses a micro-processor to interpret the information. The carrier is so designed that alternations made in it after it is coded are immediately detected by the evaluation circuit. A particular relationship of the reading head to the information carrier is described for a particular pattern of loop-shaped information elements on the carrier.

Description

B~CKGl~OUND_Ol; ll~ ~N_I`N'IIOIN

The invention relates l:o a cylincler loek and key ror establishing an authorization to operate the cylinder lock.
The key eontains in~ormation which can be read by readin(3 deviees in the eylinder lock.

T/ocking systems eomprising a plura]ity of lock cyl;nders are used not only ~or locking or unlocking premises or the like, but also in speeial cases for cheeking whetller the neeessary authorization exists. ~uthorization eovers not only time-llmited authorization for aecess to partienlar premises, but also au~horization to remove c300ds or artie]es from automatie maehines, sueh as e.g. pumps at filling stations. The known loeking syster.ls have meehanieal checking of authoriza-tion and, as a result, there are very few coding possibilities for such mecllanieal authorizatlon ehecking.

DOS 2,546,542 deseribes the arrangement of magnetie means on a key servina to extend the eoding possibilities for sueh an autllorization eheeking. liowever, tllese magnetie means have the disadvantage that they ean easily be deliberately ehallged and/or the eode rendered visible with simple auxiliary means. Thus, this eode provides not mueh greater seeurity than the known mechanical code arranged in the form of slots and/or holes on the key.

~,, SU~ RY OF TIIE INV~:NI'[ON

In the novel lock and key In accordance with the invention, a macJIletic passively and induct:ively readable inormation carrier for identifica-tion of the key is arranged on that part of the key which can be inserted in the lock cylinder.

~3~ F Dl'SCRIPTION OF 'I`IIF'I~R~WINGS
. ~

Fig. l is an elevated perspective vie~w of a cy]inder lock and key in accordance with a preferred embodiment of the present invelltion .
Fig. 2a is a side, sect;onal view of a fragment of an information carrier of the key of Fig. l, showing coding ]oop elements of electrica]ly conductive material vn an information carrier and showing schematically a reading head for interac-ting with the coding loop elements.
Fig. 2b is a top view of the fragment of Fig. 2a, showing the pattern of the coding loop elements.
Fig. 3a is a schematic circuit diagram of one of the coding loop elements of Fig. 2b in the process of being read by the reading head of Fig. 2a.
Fig. 3b is a schematic circuit diagram of another of the coding loop elements of Fig. 2b in the process of being read by the reading head of Fig. 2a.
Fig. 4 is a block diagram of an electronic evaluation circuit for processing the information from the readlng head of Fiy. 2a.

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Fig. 5 is a c~oss--sectional v:icw oE a fragmerlt of the key of Fig. l at the narrow edge of the blade, showing tlle infor-mation carr;er of Fig. 2a.
Fig. 6 is a partially sectioned plan view of the side of the reading head of Fig. 2a which faces the information carrier of Fig. 2a on the key of Fig. 1.

D]`'l`l~IT.F,D DESCRIPTION OF TIIE PRF,FEI Rl-~.D EMB D IM N'l'S

In a symboLic sectional view, Fig. 1 shows the cyllnder lock , WiliC}l in a per se known manner comprises stator 2 alld rotor 3.
In the rotor 3, the key 4 with its blade 5, which in per se known manner has a number of recesses and/or holes 51, is used for actuating the not-shown tumbler pins provided in the lock cylinder L. An inforl-nation carrier, described in greater detail beLow relative to Figs 2a, 2b and 4, is provided on the narrow side of key blade 5. T]le width of the information carrier must be narrower than -the width of key blade 5. If the key is now inserted in the slot of rotor 3, the information carrier 6 moves with the key 4 past the reading head 7 located ln stator 2. As i will be described in greater detail hereinafter, this relative movement between information carrier 6 and reading head 7 produces a number of different items of information/ SUC}I as e.g. the speed and direc-tion of the relative movement, the stalt and end of the information as to key identification and as t:o the gen-uineness or validity of this identification. It is thus possible to immediately establish not only the identity of the key, but also any change in this identity. The signals received by : .
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rl-~aclill-3 head 7 as a resu]t of ~he relative mov-?~ ?nt o~ th(~
information carrier 6 is trans]n;tted by a not-sho~ln l;nc to the electronic evaluation circuit shown in Fig. 9, in which i-t is evalua-ted in such a way ~hat the identity of the key and its authorization or any for(3iny can be cstab]ished.

In the embodiment of l~ig. 1, kcy ~ is r~presented in such a way that the recesses 51 are loca-ted on the wlde side of key l~lade 5 and the information carrier 6 on tl~e narrow side.
Clearly, the informatioll carrier 6 can be arrangcd on lhe wide side of the blade in the case oE a key which has protuberallces and depressions for act~lating tlle tumbler pins in the lock cylinder on the narrow side of its blade. The arrangemellt of t:he reading head 7 in cylinder lock 1 and the information carrier 6 on key blade 5 can therefore be subsequently e~fort-lessly and easily incorporated into any exist:ing locking system.

Fig. 2a shows in a partial sectional view the reading head 7, .
with two of its four read windings A, B, C, D which, according to Fig. 6, are connected -to the electronic evaluation circuit.
Fig. 2a does not show the electrical connecting lines. In Fig.
2a, reading head 7 is sectioned along tlle section line I - I of Fig. 6. The key blade 5 with information carrier 6 is located a certain distance below the reading llead 7. The inforlllation carrier 6 is covered by a ~rotective ]ayer 71. 'rhis protectlve layer 71, which will be discussed in dctail in conjunction wit:h Fig. 6, comprises an electrically non-conductive and maglletically passive material, such as, for example, a diamac3netic material pemut-ting reading through it by magnetic Eield excltation. The _ 5 _ 5~

.
lnformati.oll carrier 6 cornpr.ises a p.lrt:icular printcd ~ euit pattern 8, whose mat-erial is electricdlly conductive and an inslll.ator 9 whicll i.s el.ectl-ically non-conductive and prcferably has ferrolllac31lctic pr.OpeLt:ieS.

Fig. 2b shows the patterll 8 of e]ectrically conduct;ve material arranc3ed in a speci~ic manner on insulator 9. In the plesent embodiment, tlle pat-tern 8 cornprises a series of ].oop-like elemellts ]Ø Such an elenlent 10 is shown particularly cle~arly ;n~ F;g. 2b. Pattern 8 is coded by opening the short-circuit bl-idyes 11 of l:lle indi.vidual ]oop-like e]ements ]O. Each eLelllent 10 is a bit which, dependiny on whether short-c;rcuit bridge 11 is pre.sent or not, can be logic "1" or "O". A].1 the bits of loop pattern 8 on information carrier 6 are subdivided ;nltO an information code and a test code. '~he information code establishes the identity of the key. The test code gives infor-mat.ion on whether the identi.ty is ~3enu;.ne or a fo:rgery. Accord-;.ng to Fig. 2b, it is assumed -that the uncoded pattern 8 still eonta.;.ns all sho.rt-circuit bridges 11 and that during coding -the br.i~ges 11 are removed by c3rindi.ng, scratehing, burning away, evaporati.ng or etching. 'rhe test code indicates in the form of a binary number how many short-circuit bridges 11 in the infor-mation code are opened. Sinee any damage or modi~ieation leads to the opening of further loop-l.i.ke elements 10 w.ith a resulting increase in the number of interruptions c3iven in -the test code, - the binary test code then no longer agrees, so that the key ean then be recognised as invalid. In the test code, one short-eireuit bridge 11 eorresponds to a logie 1, i.e. this binary number ean only beeome smaller, and never larger, th~ougll damage i2~

to the test code. As a resul,t, al1y existir1cJ valid codc cc~n on1y be chal1c3ed inio an invalid code.

For reasons of clari-ty, in F:ig. 2b l~ e pole loc~tions of -the read willdin(3s ~, B, C, D of reading head 7 are shown. With respect -to the poles of the read winclings of the reac~ g head 7, pat-tern 8 is either moved :in a direction indicated by arrow 13 or in t:he opposite direction. In the present embodiment, it is assul1led that direction 13 is the direction of movement occurring on inserting key 4 into lock l (Fig. l). Elernents 10 of pattern 8 are so shaped and constructed that one pair of poles (e.g. read windinys A, s) has a 90 yeome-trical phase displacement to the other pair of poles of read winding C, D, while the pair of poles of read windings B, C has a 180 geometrical phase displac'ement to the other pair of poles of read windings A, D. This arrange-ment can also be achieved throuc3l1 spacings of the poles of read win(1il1c3s R, B, C, D of reading head 7 having other spatlal dimensiolls. It is not necessary in this case to change the pattern 8 of the loop-like elements lO in any way. It is important that the relationship between the pattern 8 and the palrs of poles of reading head 7 is dimensioned in such a way that the above-defined phase displacements are obtained. In the embodiment of Fiy. 2b, these relationships are represented throuyh the pole of read windil1g B being arranged within loop ]0, while tl1e pole of read windings A is already partly outside that loop.
The same applies in the case of the poles of read wil1dii1g C and D, but the siyn is reversed. This means that there is a 180 phase displacement between one pair of poles (B, C) and the other pair of poles (~, D). The same arranc3ement of the four poles . .

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also giv~s a 90 phase disp]acemellt between tlle pa;r o~ poles of read windill~s ~, B and ~he palr of poles of read windlngs C, D. In pr;nciple, it is not necessary for the pattern 8 to be formed froln a series of loop-like elelnellts ]0. ~attern 3 can also comprise discre~e or individ-lal loop-like or area elements 10.

Figs 3a, 3b show the production of inforrnation signals from l:he loop-like e]ements 10 of Figs 2a and 2b.

~ ig. 3a shows the arrangement of a loop 10 under two poles of read wlndings B and D/ -the latter being excited in such a way that there is obtalned a magnetic flux 12 which is of equal phase with the two poles. This is indicated by the cross in Fig. 3a.
~laglletic flux 12 flows back across the electrical insulator 9 with ferromagnet:ic properties of the information carrier 6 to tlle poles of the two other read winclings A and C. Tn loop 10, the magnetic flux 12 produces a secondary current iXS f]owing in the direction of the arrow throuyh loop 10. The short-circuit bridge 11 (see also Fig. 2b~ of loop 10 can be present or absent.
Tll~s changes nothing as regards the flow of secondary current in loop 10. Fig. 3a shows -the state whereby there is a given position between reading head 7 and information carrier 6 of key 4 giving informa:tion to the evaluation circuit shown in Fig. 4.
Reading head 7 can also read the preset information as in Fig.
3b. To this end, read windings B and D are excited in such a way that in the pole of read windlny B a magnetic flux 12 can flow in a given direction across electrical insulator 9 to the poles of the other read windings A and D. In this case, read .
-- 8 ~

~in~li3lg C is excited in the same way, so thal- a magnel:ic ~]ux Wit}l the sallle direction results. With this directioll conf:igu~
ratlon of mac~netic flllx 1~, a secondary c~lrrent iy can flow in loop 10 if short-circuit bridye ]1 is present. In this case, the current flow directions in both halves of loop 10 are opposite to one another. This is indicated by arrows. If short-circuit bridge 11 is not present, no secollclary iys can flow. It is tllerefore apparent that by a relnoving of the short-clrcuit briclye 11, a code can be provided in pattern 8 in yiven manner (Fig. 2b). 'rhis code gives the infor~ation on the identification and cllecking as to whe-ther or not a forgery exists. It is also pointed out that in Figs 3a and 3b the direction of macJnetic flux 12 represents a momentary value of an alternatlng fleld.
By mcans of Flgs 2b, 3a and 3b, an embodlmellt for obtalning inforMation was described in which the pattern 8 represents a slngle interroga-tion track. 'rhus, the poles of lnterrogation willdillgs B, D of read head 7 are used in two ways (Figs 3a and 3b).
l~owever, there is also a possib;lity of subdlvidin~ the pattern 8 on information carrier 6 into two or more spatially separated tracks. In this case, it is not necessary for the poles of reading head 7 to be used twice. The two or more tracks of pattern 8 can either be located on a single information carrier 6 or on a plurality of information carriers. For example, inEor-mation carrier 6 can be arranged on hlade 5 of key ~ in the mallller , .
shown in Fig. 1, and the other information carrier call be on the opposite narrow side of blade 5 or, if holes 51 are not present, on the wide side of blade 5. In this case, there are required the same number of reading heads 7 as information tr~c]cs.

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Fig. 4 shows an embodilnellt of an evaluation c,;rcu:it in ~,/hich the two oscillators 14, 15 procluce voltages UX ,Ind uy wi,th dir~erent frequencies and provide thern on the following Inatrix 16. ~atrix 16 can be eqll;pped wi~h cliEferent types of active or passive elect:ron;c components. In ~he case of the present elllbodiment, it ls assumed that the matrix comprises higll-valued resistors. It is constructed in such a way that ~he sum oE
currellts ix -~ iy appear on line 17 and is supplied to e~citing willding A. The frequency of current ix corresponds to that of oscillator 14 and Erequency of current iy to that of oscil]ator 15. The frequellcies of the sum current ix -~ iy Oll line 17 are superilnposed. The same sum current as is in line 17 ap~ears also in line ]8, but with a neyative sign, as indicated in Fig.
4. ~.rhis sum currellt passes to read windirlg B. The differentjal currellt~ iy of the two voltages from oscillators 14 and ]5 appears on line 19. The fre~uencies of these oscillators are correspondingly superimposed in the differential current of line 19. The differential current is fed to read winding C.
The same differelltial current as is in line ]9 appears also in line 20, but with a negative sign, as shown in F~g. 9. 'rhe differential current of line 20 is fed to read winding D. Thus, read windings A, B, C, D of reading head 7 are excited in accordance with the currents and in -the loop-like elements 10 of pattern 8 of inEormation carrier 6 prod~lce secondary currents indicated e.g. by'arrows in Figs 3a and 3b. These secondary currents produce feedbacks in the read windillgs A, B, C, D which change the impedance of those windings. This leads to voltage challges in currents supplied to adders 21, 22. Each adder has ; "' , J'~ ~2 all output which is su~pli.cd to a ~oll.ow:inc3 arnplif:ier 23, 24.
'.I`he volta~Je lluctuation wi.~h the frequency mi.xture from oscillators 14 and 1.5 alld whi.ch comes fro]n amp]ifier 23 is so processed in the fol10wing r:ing deTIlodulat(>r 25 that the colllponent having the requen~y of oscil]ator 14 i.s f.i].t.ered out, delllodulated, and fed to the following Schmi.tt trlgger 26. rr}li.s takes place in ring clemodulator 25, due to the fact tllat oscil.lator 19 supp].ies its vol-tage UX not only to matri~ 16, but also to ring clemodu]ator 25. The voltage fluctua~ions with the frequc~ncy m.ix of oscilla-tors .]4, ]5 and coming .Erom amplifiel 24 are so processed in the follow;ng ring dernodulator 27 that tlle compon'ellt with the frec~uency of the oscil]ator 14 is filtered out, demodulated, alld fed to the following Schmitt trigger 28.
Therefore, oscillator 14 is also connected to ring demodu]ator 27.

Tlle signals coming from -the two Schmitt -triggers 26 and 28 are two pulse sequellces'displaced hy 90 which Lepresent the position of the loop-like elements 10 under reading head 7 and ~he speed and direetion of the re].ative movement between infor-mation carrier 6 and reading head 7. These two signals are fed to logie eireuit 29, whieh proeesses them in sueh a way -tha-t the storage loeations i.n a foJ.lowing shift register 30 are,filled in the same way as key 4 is introdueed ;.nto the slot of rotor 3 of lock cylinder 1. Shift register 30 represents a preeise eleetronie diagra~l of -the meehanical posit.ion of the key relative to the loek eylinder. This means that it is established eleetronieally together with the pOSitiOIl of the key whieh it momentarily occupies whether the key is moving in or out of the ~' ' .

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lock. The logic circui-t 29 is of a gen(-rall.y kno"n type which corresponds to the kno"n princip1e o-~ ]ength measureinent ;n machine tools.

In Fig. 4 the two outpu~s of arnpli.fi.ers 23 alld 24 are connected with a rlng dernodulator 32 via.an ad(1er 31. rhe acider 31 sums the output sigllal (vo]tage fluctuat:iolls of read windlngs A, s) of amplifier 23 and the inverled output signal (voltage fluctuations of read windinas C, D) of amplifier 24, thi.s being represented in the drawinc3 by the mathematical symbols ~, - . The output signal of aclder 31 is Eed to ring demodulator 32, which fil-ters from the vo]tage fluctua-tions only that part having the frequency of oscillator 15. This is followed by demodu]ation. Irherefore~ ring demodulator 32 is conllected to oscillator 15, wllicll supplies i.ts voltage uy not only to matrix 16 but also to ring demociulator 32. The output signal of ring demodulator 32 is supplied to .Schmltt trigger 33.
The signal from Schmitt trigger 33 contains the information from the information carrier 6 of key blade 5. Togetller with the already described signals from logic circuit 29, this information is fed into shift register 30 and in the latter is stored in the corrèct position. When.key 4 has been completely inserted into lock cylinder 1, -tle informati.on is completely available in the shift register, without regard to -the speed w.ith which the key is inserted into the slot of rot:or 3. Th~ls, it does not matter whether key 4 is introduced continuously, or rapidly, slowly in a jerky manner or in short reciprocating movements into the slot of rotor 3 of cylinder lock 1. At all times, shift ~;' , .
~ 12 -52~

register 30 stores the inrormatioll, wh:ich .i.Jl lhe part of a p~ittern 8 of inforrnation carrier ~ on key 4 is just heillg moved past readin~ head 7 in the inser-llon rnovcment direction.
~hen key 4 has been cornple~ely inLierte~ into lock cylinder 1, calculator or adder ~r processes the information of shi~t register 30 so as to establish whether the part;cu]ar kcy has an authorization, e.g. for openilly the doors, for removing information from data banks, for removing goods from vending or (lispensing machines, for usiny equipment, tools or instruments, etc. ~t the same time, this information establishes the autllority of the key. It is pointed out here that adder ~ compares the informa-tion content of shif-t register 30 with data giving information on the authorization`and authority. The adder also establishes whether the informatlon stored :in shift register 30 is correct or falsiEied.
~8 Calculator or adder 31 is presen-tly commercially avai]able and is marketed as a microprocessor by well known computer companies such as INTEL. In accordance with the result of the ~ 3y checking, adder ~1 supplies signals to different peripheral equipment. Fig. 4 gives a selection of such peripheral equipment.
; Thus, the calculator can e.g. give an optical indicating device 32 the result of the authorization, identification and correctness of the information and the time at which this took place. Such ;~ an indicating device can e.g. be celltrally installed in a control room. The calculator can supply the same~ output sigllals to a recorder 33, constructed either as a printer or as a store ; (magnetic store, punched tape, microfilm, etc). If the result ', . .

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from calcuLator ~I is in order, it -ulJplies a sic~al (-o t-he e~
unblocking devlce 34, ~ . locaLcd on the door to be unl~]ocked.
The unblockin~ devlce 34 can also be provldecl on machilles for velldillg or dispens:iny yoods or for movillg information frolll data banks. ~owever, if the checking resu]t oE calcu1.1tor ~r is nec~ative, a signal is supplied to b]ocking device 35 arranged at the same ]ocat;on as indica~ed hereil~beEore. In addition, in the case of a ne~ative rcsult an a]arm device 36 can be operated. This alarm device can be set oEf if there is no authorization, if falsified :information appears, or if there is used a sought identified in -the lost property register.
Calculator ~ can also be connected to a counting device 37, which is preferably used on machines for dispensing c~oods, as well as on equipment, vehicles, e-tc. At the end of a given time, e.g. a month, an abstract from this counting device is supplied to the owner of the key. In the case of the present embodiment, only a limited number of peripheral devices can be used. It is ndturally all aim o~ the invention to be able to use other periplleral devices. To provide a better understandillg of the operation of calculator ~, it is poillted out that the criteria for the autllorization and the identification are located in a ~ 3~Y
store, wllic}l can be arranged either within the calculator~r or ln the vicinity thereof. The conte!lt of the store can obvious:Ly be changed on a time basis, so that not only an identification, but also a time-dependellt checking of authorizations can take place. The electronic circuit of Fig. 4 has hitherto been descri~ed in such a way that the two oscillators 14 and 15 supply volta~es ux, uy with different frequencies. I~owever, these two .
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:

osclll.ato.rs can also be modi.fied in s~lch a way that ~ cy s~]L)ply vo].tac3es ux~ uy with the same frequency. The phase pos:iLions of these two voltac~es must then, however, be d;spl.ace'd by a constallt an~le re].a~ive l-o one anotller, preferably ~/2. The impedallce chanc3e ln read wincli.llgs ~, B, C, D clue to t:he secolldary eurrents in loop pattern 8 on inEornlation carrier 6 leads not only to an amplitude change, but also to a phase change (mod~llat:ion)'. Sinee tlle riny demodulators 25, 27, 32 are not only a .Erequency-sensiti.ve filter, as described in the first enlboclimellt, but are also a phase--sensi-t.ive filter at the output of Scllmitt triggers 26, 28, 33 with the sarlle ci.rcuit principles, the same si.gnals are obtained as in the embodiment with two differellt frequencies.

The use of a time division mul-tiplex leads to a fllrther variallt of the embodiment of Fig. 4 Eor reading the inforlnatlon o~ loop pattern 8 with reading head 7 and producing it in corresponding pulse sequences at the outputs of Schmi.tt tr.Lggers 26, 28, 32. The upper part of the circuit of Fig. 4 is only s.liyhtly cilallged for thi.s variant. The two oscillators 14, 15 are replaced by an oscillator for exciting the read windings A, B, C, D. Matrix 16 is replaced by a multiplex switch which at short time intervals switches tlle oseillatox on lines 17, 18, 19, .
20 in SuC]l a way that alternatively the two l~osition si(3nals and tlle inEormation signal are measured by read willdings A, B, C, D.
The ring demodulators 25, 27, 32 ean be replaced by ordi.nary reetifiers. Behind eaeh of the,Sehmltt tri.gc3ers 26, 28, 32 is eonneeted a storage deviee whieh stores the sic3nal of the immedlately preceding time interval.' The storage device reee.ives i . j .
~ ~ 15 -.
.

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;l-s setti,ng instI-uclions in the salne rhylllm as that in ~h:i,ch tl~e mu],ti,plex switch is switched over.

Fig. 5 shows a sectional view oE part of key blade 5.
slot approxilllately 2.5 r~n wide is made ;n the narrow s;de of key blade 5. The iniormation carrier 6 comprising the insu]ator 9, the pattern 8 and -the protective layer 71 is inserted i,n ~his slot. The indi,vld~al par~s of the information carrier 6 are ' joined together prior -to insertion. The joining can either be made by mealls of an adhesive material, such as e.g. polymerising , synthe-tic resins or by melting or by evaporating on ancl/or clefusing. These mel:hods are known, so that no more detailed information is required. llowever, it is pointed ou-t that the protective layer 71 and pattern 8 must be joined together in such a ~ay that pattern 8 is destroyed if an attempt is made to relllove the protective layer.

`' Glass, ceramics, metal oxides, e.g. aluminium oxide or sil,icon dioxide or the like can be used as the protectlve ]ayer material. The protective layer is required to be chemically and mechanically resistant and magnetlcally and electrically ,~ ' neutral. It must also be opaque and have approximately the same heat expansion coefficient as information carrier 6. It is again pointed out here that -the information carrier 6 comprising electrical insulator 9, the pattern 8 and the protective layer 71 has a thickness of approximately 0.5 mm.

, Fig. 6 shows the reading head 7 of information carrier 6~

The diameter of the reading head 7 is approximately 3 l~n. It is easi.]y possil,le -to see the active surr;lces of the poles aro~ d w}licll tllere are arranged the read wincl:;nc3s ~, ~, C, D. ~rhe ends of the read wi.ndirlc3s are connectcd to the evalllati.on Cir.CU:It ;.n the manner.shown in Fi.g. 4. ~ e poles, or active suxfaces, of the four read wincli.ngs are posi.ti.olled re].ati.ve to pattern 8 of lnformati.on carrier 6 in the same way as im the exarnple shown i.n Figs 2a and 2b.

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLU-SIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An improved lock and key combination wherein the key is insertable in the lock and has coded information for identification and control of access of the key, compris-ing an information carrier mounted on said key comprising an electrically nonconductive and magnetically conductive sub-strate, and an electrically conductive pattern means carried by said substrate for carrying a code containing desired in-formation; a reading device positioned in the lock; electronic control circuit means coupled to said reading device for pro-ducing an alternating magnetic field to generate an electric alternating current in said pattern means; and electronic evaluation circuit means coupled to said reading device for receiving feedback signals representation of said alternating current for recognition of said key.

2. A lock according to claim 1, wherein said elec-trically conductive pattern means is formed as a plurality of electrically conductive loop elements arranged on said electrically non-conductive and magnetically conductive sub-strate whereby said alternating magnetic field generates said alternating current in each of the loop elements.

3. A lock according to claim 1, wherein said electrically conductive pattern means is shaped as a plural-ity of electrically conductive plain shaped loop elements arranged in a predetermined manner on said electrically non-conductive and magnetically conductive substrate, and wherein said reading device includes a plurality of coils, whereby said alternating magnetic field controlled by said electronic control circuit means and produced by said coils generates said alternating current in each of the loop elements and produces feed back to said evaluation circuit.

4. A lock according to claim 2, wherein each of said electrically conductive loop elements arranged on said electrically non-conductive and magnetically conductive sub-strate means represents one information bit and all said ele-ments together give a security code containing a test bit and an identification bit, the test bit representing the cross-sum of the digits of an inverted identification code as a binary number.

5. A lock according to claim 1, wherein said read-ing head in the lock and said information carrier on the key are formed and arranged with respect to one another in such a way that during the relative movement between the key and the lock cylinder there are produced two timing signals re-presenting the direction of movement and speed of movement and one information signal representing identification.

6. A lock according to claim 1, wherein said elec-trically conductive pattern means or information elements is fixed to said information carrier and covered with a protec-tive layer.

7. An apparatus to test the identification and the access authority of a key coded by electrically conductive pattern means arranged on an electrically non-conductive and magnetically conductive substrate means, wherein said key is inserted in a lock having a reading device for reading the coded information on said key activated by an electronic ex-citing circuit and supplying electrical signals representing said information to an electronic evaluation circuit, and wherein said exciting circuit comprises: two oscillators which generate voltage signals with two different frequencies and supply said voltage signals to read windings of a reading produced in the lines of said read windings as feedback re-presentative of said elements of said information carrier to a storage device such that the content of said storage device gives a precise indication of the position of the key rela-tive to the lock and of the coded information from said in-formation carrier.

8. An apparatus to test the identification and.
the access authority of a key coded by electrically conductive pattern means arranged on an electrically non-conductive and magnetically conductive substrate means, wherein said key is inserted in a lock having a reading device reading the coded information on said key activated by an electronic exciting circuit and supplying electrical signals representing said information to an electronic evaluation circuit, and wherein said exciting circuit comprises: two oscillators which gen-erate voltage signals with the same frequency and different phase and supply said signals to read windings of a reading head of said reading device, and said evaluating circuit com-prises: circuit means for transmitting the voltage fluctua-tions produced on the lines of said read windings as feedback representative of information elements of said information carrier to a storage device such that the stored content of said storage device gives a precise indication of the position of the key relative to the lock and of the coded information from said information carrier.

9. An apparatus to test the identification and the access authority of a key coded by electrically conductive pattern means arranged on an electrically non-conductive and magnetically conductive substrate means, wherein said key is inserted in a lock having a reading device reading the coded information on said key activated by an electronic exciting circuit and supplying electrical signals representing said information to an electronic evaluation circuit, and wherein said exciting circuit comprises: an oscillator which gener-ates voltage signals which are fed to read windings of a read-ing head of said reading device in a given time sequence by means of a time division multiplex switch, and said evaluat-ing circuit comprises: circuit means for transmitting vol-tage fluctuations produced in the lines of said read windings as feedback from information elements of said information carrier to a storage device such that the stored content of said storage device gives a precise indication of the position of the key relative to the lock and of the coded information from said information carrier.