CA1264954A - Apparatus for electromagnetic locking on a lock cylinder for a mechanical/electronic locking system - Google Patents

Abstract

A B S T R A C T

The electromagnetic locking apparatus functions on a lock cylinder with a rotor, to whose end is fitted in rotation-restrained manner a driver and a stator surrounding the rotor.
It is positioned with respect to the lock cylinder and a control part engageable with the apparatus. The apparatus is characterized in that the locking means (20, 28) have an electromagnet part (20) with a two-part tie rod (401/402) with a return spring (45) acting on one tie rod part and a probe (28) connected to the other tie rod part (402).

Description

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APPARATUS ~OR ELECTROMACNETIC LOCKING ON A
_ LOC~ CYLINDER ~OR A I~ECHANICAL/ELECTRCNIC
_ LOC~ G SYST~;1 . _ rhe present Lnvention is in the field of security tecnnology and reLates to an apparatus for electromagnetic lockin~ on a lock cylinder according to the preamble of claim l.
On tsle basls of an electronic lockin~ system on a lock cylinder according to the prior art (e.g. Swi99 patent application 6903/82~ for blocking or allowing the relative movement between rotor and stator, the problem of the present inventlon i3 to so ~urtr.er develop an electromagnetic locking system that it provides an L..proved security witn resyect to tne opening/closing function, in the case of operating failures, such as power failures and the like or when safety or security elements fail, aq well as in the case of attempted forced entry.
The problem is solved by t~e invention defined in the characterizing part of claim l. In the case of a Lock cylinder to be locked electromagnetically, according to tne invention the rotor is released e1ther by the mechanical key associated therewith and/
or by the electromagnetic locking system according to tne invention.
An electromagnetically lockable lock cylinder has the advantage that it can be released via electromagnetic means, e.~.
electronically, time controlled, programmed, etc. A key belonging to the lock cylinder can then have electronic and mechanical or solely mechanical opening means. Tne electromagnetic locking ~1 ~, ' ~'`' ' ' .

64~3~4 system can also be released, ~.g. in remotely controlled manner, independently o~ the key.
More particularly, this invention provides locking means for a lock of the type having a lock cylinder with a rotor, a driver mounted on one end of the rotor and restrained against rotation relative to the rotor, a stator substantially surrounding the rotor, electromagnetic locking means mounted adjacent the lock cylinder and a control part having a shaped control surface mounted on a rotatable part of the lock and engageàble with the locking means to control unlocking of that rotatable part, wherein the locking means comprises an energizable electromagnek coil, a tie rod having first and second coaxial, axially movable parts movable between abutting and spaced positions, said first part being axially movable in a first direction by said electromagnet coil and said parts being axially movable together when an energizing signal is provided when said parts are abutting;
a return spring urging said first part in a direckion counter to said first direction; and a probe fixe~ly attached to an end of said second tie rod part and engaging said control surface of said control part, said probe preventing rotation of said control part relative to said probe in the absence of an energizing signal provided when said tie rod parts are in an abutting relationship.
The invention is described in greater detail hereinafter relative to a non-limitative embodiment and the attached drawings, wherein show:
Fig. 1 An example of an electromagnetic locking means according to the prior art for the further development of the invention.
Figs. 2 ~ 3 In longitudinal section the electromagnetic locking means arcording to the invention broken down into an electromagnetic base part and a scanning part.
Figs. 4 & 4A to 4C An example of a slidinq link in the form 9~;~
-2a~
o~ a ring for the engagement o~ the ~canning part and three views relating to the development o~ said link.
Figs. 5A, 5B & 5C The locking means according to the invention in three operating states.
Figs. 6A & 6B An additional security means in the blocking zone of th0 apparatus.
Fig. 1 shows an electromaynetic locking means lO
according to the prior art, which can be used ~or electromagnetic locking on a lock cylinder. It is possible to see an e.g. cylindrical housing 25, which encloses the electrical and mechanical locking ~parts. A bobbin 24 carrying the magnet coil 23 is inslerted and flxed into ~,.

~2~ ;4 the cylindrical lock housing. Tne armature 21 passing throu~h tne inner portion of coil 23 carries at one end a rstaining ring 27, which is sufficiently large to act as a longitudinal movement limiter for the stop 29 located on tne nousing end. A compression spring 26 acting between bobbin 24 and retainin~ ring 27 in the form of a ret~lrn spring brings the armature 21 into a clearly defined position with respect to the housing 25 and also with respect to a sliding link flxed e.g. on the rotor end of the lock cyllnder. T'ne magnetic field produced by the excited winding draws the armature 21 against the tension of compression spring 26 up to the armature stop 22 and si~ultaneously a clearance 21' i3 provided in the longitudinal direction for a probe 28 en3a~ing on tr,e ar~ature, so tr.at t;ae clearance obtained permits ~ link play.
Fig3. 2 and 3 snow a special embodiment of an electromagnetic lockin~ appar~tus 20, 28 cooperating with a herelnafter described control link (Figs, 4, 4A, 4B, 4C). An electromagnet part 20 with an exciting winding 41 and a special two-part, prestressed tie rod 401, 402 acts on a scanning part 28, into which is integrated one part of the two-part tie rod. In tnis case, scanning par~ 28 nas a sliding pin 50 and a sliding flank 50*, which are moved alons an aforementioned control or sliding link 60. In tne represented embodiment, thiq is an annular part, which is e.g. fixed to the lock cylinder rotor. Figs. 4 to 4C show the exarr,ple of a completely constructed control link, as used in preferred manner in conjunction with the invsntion and whose operation will be described nereinafter.

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In detail, Fig3. 2 and 3 show the electromagnetic locking means. Fig. 2 shows the electrical base part 20 with excitln~
coil and tie rod part 401, whil~t Fig. ~ 3hows the scanning part 28 with sliding pin 50 and slldlng flank 50~, as ~ell aq the other tle rod part 402. The breaking down of the tie rod into two parts has the followin~ special aspects. rhere i9 to be a reclprocal dominance interactlon between the control link and an electric excitlnæ pulse, i.e. ln the presence of an excitlng voltage and prlor to turning about a glven rotatlon an~le, tne two tle rod parts 401 and 402 magnetically 3tick together. On exceeding this angle, magnetic bonding i3 prevented by the link as a result of the air æap formed.
To per~it ~orkin~ in an electronic low-power, but safety-conscious manner, on attractin~ the magnet, the ~agnetic flux must be at a maximum. At the instant at which the Yolta_e is to bring about a holding together of the tie rod, the air ga? must consequently be zero. This i9 guaranteed by a tolerance compensation 3pring 52, a compression spring between the probe body 51 and tne tie rod part 402 placed on the front end and which is displaceably secured by means of a retaining rin~ 48 against the spring action on probe body 51, wnilst also being sli~htly prestressed. rolerances in tne link of control part 37 can lead to the probe body 51 being moved out of its air gap equal to zero po~ition, e.g. with sliding flank 50' pre3sed in the direction of the tie rod or witn tne sliding pin 50 drawn in the opposite direction. As a function of tne manufacturing tolerance of the components, this compression/tension is taken up by the . ~.

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tolerance compensating spring without any change to the alr gap equal to zero condition. In the case of an addltional biaslng of said spring durinz enga2ement in the sliding link, the manu-facturlng tolerances of the link are compensated in mo~ement-wise manner. In addition the pressure acting on the tie rod parts prevents zero clearance changes in the case of intentional or unintentionaL vibration to the lock cylinder, which greatly increases operational reliability.
Fig. 2 shows the exciter part of the electromagnet with a bobbin 44 and an excitin~ coil 41 wound on to the same with one part 401 of the tie rod 401/liO2 and with a compres~ion spring 45 as the return spring. A retaining rin~ 48 ia located in a slot of tne tie rod and absorb~ the tension of the ret~rn spring. The coil is surrounded by an ln thls case cylindrical housing 42, a recess being provided for electrical connections 47. For the desired operation with minimum energy requirements, the exciter part must be closed by covers 46, whicn serve to close the magnetic circuit and as shown, simultaneously support the retaining ring.
Scannin~ part 28 already discussed in connection with Fig. 3 is inserted in the exciter part at the time of assembly (cf. also Fig~. SA B C). 3etween tne electromagnet part 20 and the scanning part 28 is provided a third compression spring in the form of a retaining spring 55. ~he probe of scanning part 28 which is in tnis case realized by a sliding pin S0 and a sliding flank 50* on a probe body 51 engages witn a control part and in the present embodiment it is in the form of an annular sliding link 60 drawn on to or applied to the circumference of the stator if the latter is arranged in rotary manner, or otnerwi~e on to the circumference of the lock cylinder rotor. This probe 50, 50* can engage in a web-like sliding link 60 (or ln anot~ler embodiment by means of a scanning pin in a correspondingly constructed sliding grooYe) and is controlled by control elements, such as cams and depressions shaped into the sllding link. [n this case, the sliding link 60 has retaining flanks 63, on which can be engaged the 31iding flank 50~, i.9. a rotation of the driver acting on the lock by an angle permittine the opening or clo~ing of the latter is dependent on the position of the sliding flank 50~ witn respect to the retaining flank 63. The desired clos$ng/opening function can be brought about by the mecnanical relea3e of tre key (tumblers) or by tne electromagnetic release throu~n tne locking means. A series connection of mechanical AND and electromagnetic locking i3 also possible.
Figs. 4 and 4A to 4C show the annular embodiment of the control part in three viewing directions, as well as a development of the associated control link 60. ~he neutral or inoperative position of the cylinder prior to the opening or closing on the link is 0. A rotation in direction ~180 e.g. brings about a closing of the lock and rotation in the direction -180 an opening of the lock. Both functions are equivalent, so that the link i~ symmetrical when related to zero. If the pull magnet i~
or becomes currentless,the scanning part 28 is forced against the link wall snown on the right hand side A in the drawing due to the tension of springs 52 and 55, i.e. a tolerance compensating spring and a retainin~ spring. After about lj , a rotation of tne control , ~ .

1~64~4 link brin~s about a ~uccessive separation of the two tie rod parts 401/402, because the slidinæ ~lank 50~ of scanning part 28 under the pressure force of spring 55 initLall~ runs into the d~pression and then as a result of the sliding pln 50 running on to control cam 61 on ths otner side c~f the link, tne tie rod part 402 i3 further forcibly deflected, whilst increasing the size of air gap 40. F'ollowing a roughly 45 rotation in the same direction, due to the action of retaining sprln~s 55 sliding flank 50' ia blocked on one of the retainlng edge~ 63. The now performed 1/8 turn is not sufficient for operating the lock. In addition, a clearly defined blocking or retaining poiition of probe 28 is brou~nt about by tne con~tantly acting pressure force of the retaining spring. If tnis security action falls, e.g. in the ca~e of a fracture of the retaining spring, in the case of an attempted opening turn without a magnetic puL~ng action the probe 28 is moved into a clearly defined blocking position by means Or guide cams 61 and in this position sliding flank 50' strikes against the retaining flank 63. The effect of the retaining spring is an additional security measure, in order to assist a blocking action in the normal case.
Fig. 4 show~ the development of the presently discussed control link with which tne scanning part 28 can be brought into particular po~ition~. The web like construction of the link, ~nlch ia advantageoua from the manufacturing standpoint, can be clearly seen in Fig~ 4C. The control ~eb of sliding link 60 is constructed in such a way that it maintains tne scanning part in tne open or closed position over most of its length. The control ~fl~5~

web also has further control elements in the form of cams 61 and depressions with flanks 62 and 63 enabling open/clos~d functions and authorization restrictlona to be carried out ln con~unction with exciting pulses. Fig. 4A shows the l~n~ wLth two dapressions arranged mirror symmetricaLly to the zero position and their blocking edges 63 and entry edges 62 seen from A. Fig.
4B shows the control link with the two blocking or control cams 61 seen from ~. In both caies a fixing pin 65 is shown enabling the control part 37 constructed as a link ring to be fixed ln rotation restrained manner on the mechanical closing part rotor/
stator.
Finally, Fig. 4C show3 half in cross-section and ~alf in elevation tne link rin~ from direction C, in such a way tnat all the control elements can be simultaneously seen, namely the web of sliding link 60; the blocking or control cam 61,entry edge 62 and blocking edge 63.
Figs. 5A, 53 and SC show three operating cases. These constitute the normal or basic ?osition ~Fig. 5A) with an air gap equal to zero and the probe 28 under the tension of the retaining spring 55 (optionally also under the action of the tolerance compensating spring 45). This ?osition e.g. corresponds to the 0 position. As a result of the magnetically negligible residual air gap of the compressed tie rod parts 401/402, only a small initial capacity i3 required for exciting the ma~netic circuit and ~his can correspond to the desired, following, minimum retainin~
or nolding capacity.
If the guide cam 51 slides past probe 28 with the coil ;, .

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energized and the tie rod parts connected, tne complete tle rod 401/402 i9 drawn out of the coil counter to the action of return spring 45 (FLg. 53), in order to pass said security member at 30 anæular degrees. After passing guide cam 61, the same return sprin~ ~5 draws back the probe until the sliding ~lank 50' does not strike the blocking flank 63 and tnis is then a correct opening or closing rotatlon.
In the case of a non-energized coil, the sliding flank 50~
of probe 28 pasaes along the guide cam 61 ~addltionally supported by retaining spring 55) and along flank 62 lnto the link depression, so that through the tension of the return spring and the retaining spring, the two tie rod parts 401/402 separate and an air eap L ls for~ed. This air ~ap is increased in size on pas3ing 3uide cam 61 ( Fig. 5C 30 angular degrees as in ~ig. SB) and on further rotation the sliding flank SO~ of probe 28 strikes against the blocking flank 63 of the link and rotation is prevented. Due to the low voltage and the air gap even an exciting ?ulse occurring at this time could not permit tnis incorrect opening or closing rotation. Only after resetting to the normal position can a correct function be initiated again, i.e. only wnen the air gap is equal to zero condition is restored. rhen tne exciting voltage applied is again sufficient to bring about ma2netic flux.
In operation, the ten3ions of retaining spring 55 and return spring 45 act against one another. The following measure was then taken to provide clearly defined conditions here, without making tne apparatus more expensive. In order to prevent a pos3ible blocking of rotation in tne case of energization, the restoring ~4~4 force of spring 45 must exceed tne retaining force of retaining spring 55. So that the same sprin~ can be used for both functions, as a result of a shorter return spring houaing the return sprirlg 45 is biased and by makin~ the retaining spring housing longer said disequilibrium of forces is maintained despite corresponding spring excursions. Thus, tne same spring type (spring constant + spring geometry) can be used for two dlfferent functions.
However, the tolerance compensating spring 52 preferably has a higher spring conatant than the two other springs. Its clearanc~
ia merely intended to prevent the L=O condition from being disturbed by component tolerances and i3 not intended to participate in the retaining and return spring functions.
~ n additional ~easure for increasing security involves, according to Figs. 6A and 6B, making the retaining or blocking f~ 63 back taper slightly and probe 28 interacting with the blocking flank is provided on body 51 with an annular groove 74. In the case of the control part 70 shown in Fig. 6A, the sliding link 71 has a slot-like configuration, wnicn i9 naturally also possible in the case of a web-like slidlng link. When the probe 28 runs on to the blocking flank, the groove and back taper engage, so tnat the probe is easily blocked in the axial direction.
In order to increase security, following the blocking 45 angle, it i3 possible to provide a further guide cam 61 with a compensating depresqion. In this way it is possible to fulfil the requirement of a specific exciting pulse length, so that the opening or closing process is not impeded. In tns case of an unexpected overcominæ of the first obstacle, e.g. in the case of ., .

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a spring fracture, there would still be a further obstacle to prevent incorrect opening or closing.
~ hus, a complex closing/opening condition can be super-imposed on a lock cylinder. Tnus, for operating the lock a flat key ~ith the depressions belonging to the cylinder can be used and which serve solely to release the rotor, or it is possible to use a key equipped witn electrical means whicn brings about the complex unlockLng between stator and housing. The de~cribed axial movement~ of the 3canning path and armature are performed manually by means of the key and in a forced manner through an opening turn of the key. The necessary spring tensions, e.g. of spring 45 for initlating rotation are brought about by means of ~anual force, so ~nat tne said electromagnetic locking means can be operated in an extremely power-saving manner. This means that a very large amount of power is suppl~ed by operating the key.
In order to give the key a familiar appearance, in the case of electronically controlled lock operation, the key shank preferably has milled in rows of depre~sions with a "false" code, which does not release the rotor/stator barrier.
The aforementioned prior art snows now the electromagnetic locking apparatus according to the invention is arranged on a lock cylinder.

Claims (7)

1. THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
   PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
   l. Locking means for a lock of the type having a lock cylinder with a rotor, a driver mounted on one end of the rotor and restrained against rotation relative to the rotor, a stator substantially surrounding the rotor, electromagnetic locking means mounted adjacent the lock cylinder and a control part having a shaped control surface mounted on a rotatable part of the lock and engageable with the locking means to control unlocking of that rotatable part, wherein the locking means comprises an energizable electromagnet coil, a tie rod having first and second coaxial, axially movable parts movable between abutting and spaced positions, said first part being axially movable in a first direction by said electromagnet coil and said parts being axially movable together when an energizing signal is provided when said parts are abutting;
   a return spring urging said first part in a direction counter to said first direction; and a probe fixedly attached to an end of said second tie rod part and engaging said control surface of said control part, said probe preventing rotation of said control part relative to said probe in the absence of an energizing signal provided when said tie rod parts are in an abutting relationship.
2. 2. Locking means according to claim 1 wherein said probe includes a probe body having a sliding pin and a sliding flank in spaced relationship with said pin, said probe body being slidably mounted on said second tie rod part; and a tolerance compensating spring urging said body toward an extended position on said second tie rod part.
3. 3. Locking means according to claim 2 wherein said control part comprises an annular link and said control surface comprises a cam surface for cooperating with said sliding pin and flank including a central neutral portion, sloping surfaces on either side of said neutral portion and step walls beyond said sloping surfaces for engaging at least one of said pin and flank.
4. 4. Locking means according to claim 3 and further including a retaining spring for positioning said probe relative to said control part.
5. 5. Locking means according to claim 4 wherein said retaining spring acts counter to said return spring and is arranged to supply lower spring force than said return spring.
6. 6. Locking means according to claim 5 wherein said retaining spring has the same geometry and spring constant as said return spring and wherein said return spring is prebiased to supply higher spring force than said retaining spring.
7. 7. Locking means according to claim 3 wherein said stop walls have reverse tapers relative to said sloping surfaces for positive blocking of one of said pin and flank.