EP4261366B1 - Key element, lock cylinder, locking system and method - Google Patents

Description

The invention relates to the field of mechanical locking systems. It relates in particular to a locking system with a locking cylinder and a matching key element, as well as a key element, a locking cylinder for such a locking system and a method for producing a key element.

In this text, the term “key element” refers to mechanical keys and key blanks for the production of such keys.

Lock cylinders have a stator (sometimes called a "cylinder housing") that can be attached to a lock in a non-rotatable manner and a rotor (sometimes called a "cylinder core") that can be rotated around the axis of the lock cylinder when a suitable key is inserted. The rotation of the rotor moves output means that are used to operate a bolt or other means related to the desired function of the lock cylinder.

Many mechanical locking cylinders have locking/counter-locking pairs which query the mechanical coding of the inserted key. One locking mechanism of each such pair is guided in a bore in the rotor, and a bore in the stator which is aligned with it in a basic position guides the corresponding counter-locking mechanism. The locking/counter-locking pair is pressed radially inwards by a spring so that the locking mechanism protrudes into the key channel. When a key which fits the locking cylinder is inserted into the locking cylinder, the locking mechanisms position themselves in such a way that one between the locking mechanism and the counter-locking mechanism is The parting line (i.e. the parting surface, parting line or parting point) formed by the counter-lock coincides with a parting line (i.e. the parting surface/shear surface) between the rotor and the stator, whereupon the rotor can be rotated away from the basic position.

The locking systems of interest in the present context have locking-counter-locking pairs that are arranged at an angle to the flat side, with the corresponding mechanical codings being formed by blind holes on the flat side (additional mechanical codings, for example on the narrow side and/or in the form of a profile are of course not excluded). This distinguishes them from locking systems in which the locking devices are arranged parallel to the flat side and engage in a serrated control groove in the flat side by means of lateral projections in relation to the locking axis.

In the publications WO 01/77466 and WO 2014/032191 A locking system is presented in which an extended locking/counter-locking pair is arranged in the locking cylinder at a rearmost coding position, so that the key can only be fully inserted into the locking cylinder if there is a groove of sufficient depth and with a cross-section suitable for the corresponding locking mechanism along a flat side of the key, away from the key tip. This procedure creates an additional security feature, and the number of possible permutations - which should always be as high as possible - is simultaneously increased or at least not reduced compared to the state of the art.

The US Patent 5 819 566 discloses a cylinder lock provided with an elastically pre-tensioned auxiliary locking pin which projects into the keyway, wherein the Auxiliary locking pin has a first end shaped to partially define an expanding tenon and a second end that engages a locking recess in the lock housing. The cooperating key has a key shank with a longitudinal slot shaped to engage the first end of the auxiliary locking pin, the depth profile of the slot increasing from an initial engagement depth to a functional depth. Upon insertion of the key, an axial force is generated acting on the head of the auxiliary locking pin to retract the second end of the bolt from the shell locking recess.

There is a constant need in locking technology to further increase copy protection without requiring too much space on the key for new security features and without significantly complicating the series production of key blanks and keys. It is therefore an object of the present invention to create a key element, a locking cylinder and a locking system as well as a method for producing a key element which meet this need and which in particular enable increased copy protection.

According to one aspect of the invention, there is a key element according to claim 1, namely a key element with a key shaft with two flat sides parallel to one another and two narrow sides opposite one another, ie a flat key or a blank for producing a flat key. The key element has an inlet groove extending in one of the flat sides from the key tip parallel to the key axis, which has a non-constant depth along its axial extent. The inlet groove can have a first depth in an entry area in particular and a second, greater depth in a coding area further away from the key tip.

According to the present invention, the inlet groove is undercut and the key element is a reversible key element in which the key shaft is symmetrical with respect to a rotation of 180° around the key axis.

Due to its design, the inlet groove is generally profiled in cross-section perpendicular to the key axis, i.e. the depth of the groove is not constant across its width. The depth of the inlet groove at a specific axial position is therefore defined as the average depth across the cross-section at this axial location. The characteristic of non-constant depth applies to the depth according to this definition. It can also apply in particular to the undercut as such.

The inlet groove runs parallel to the key axis, i.e. its (middle) position in the direction parallel to the plane of the flat side and perpendicular to the key axis (y-coordinate) is constant along its axial extension. This is necessary because the block tumbler meets the flat side perpendicularly or at another angle and is not, for example, guided parallel to the flat side, as is the case with tumblers that interact with serrated control grooves. The fact that the position in the plane of the flat side (the y-position) is constant does not rule out the possibility that the cross-section of the inlet groove can change over its length, which also includes the possibility that it widens or narrows over its length. An example of widening towards the rear is explained below.

On the locking cylinder associated with the key element, in particular at an axially rearmost position in a row of locking-counterlocking pairs, there is a block locking device whose total length (possibly depending on the coding) exceeds the total length of the other, regular locking-counterlocking pairs, so that a key can only be fully inserted into the locking cylinder if the entry groove is deep enough.

The block tumbler has a scanning head that widens radially outwards from a neck so that the undercut of the entry groove is scanned. If a groove of the appropriate width is available but does not have an undercut, the key cannot be fully inserted either.

Like regular tumblers, the block tumbler can also be designed to be cylindrically symmetrical (rotationally symmetrical with respect to rotation through any angle) around a pin axis.

"Undercut" is defined in relation to a direction that corresponds to the direction of the pin axis that scans the key at the location of the run-in groove. This can be perpendicular to the flat side, or at an angle to the normal to the flat side. Even if the scanning pin (namely the block tumbler) does not belong to the key, but to the lock cylinder, the orientation of the pin axis is defined and recognizable on the key element in that the run-in groove is symmetrical over at least part of its cross-section with respect to a central plane that is parallel to the key axis and passes through the pin axis.

In other words, the undercut is in particular an undercut with respect to the direction that is perpendicular to the key axis and parallel to the center plane of the inlet groove. This direction generally corresponds to the direction of the pin axis, which means that a pin with a pin engaging in the undercut Expansion (e.g. the scanning head described below) would be prevented by the undercut from hypothetically being pulled radially outwards.

The undercut can be formed on both sides of the inlet groove - i.e. the inlet groove can be undercut on both sides of its center plane, or optionally only on one side. In addition or alternatively, it can exist on at least one side (also) in relation to directions perpendicular to the flat side. The latter is also an option if the center plane of the inlet groove is not perpendicular to the flat side. The feature that the undercut also exists in relation to directions perpendicular to the flat side generally arises automatically in the approaches described in this text. It has the advantage that an area of the inlet groove is, so to speak, in the shadow for an optical scanner, i.e. an optical scanner cannot scan the inlet groove.

If a groove is undercut, at least one lateral incision is created; in embodiments of the invention discussed here, in particular two incisions that are arranged symmetrically with respect to the center plane of the inlet groove.

The design of the inlet groove as a groove with an undercut brings significant advantages. Firstly, such an undercut cannot be easily recorded quantitatively correctly with conventional scanning tools or conventional optical scanners with which key copiers work. This alone makes copying more difficult. Secondly, specially set up tools must also be made available to produce the undercut, e.g. milling machines, which produce oblique grooves to form the lateral cuts at an angle to each other and to the central plane. Even if such oblique grooves can be produced efficiently once the tool is set up and the production costs of key blanks do not make them significantly more expensive, as they have to be specially designed for this purpose, something that unauthorised key copiers generally lack the means to do. Thirdly, the undercut entry groove potentially offers double security: on the one hand, as mentioned, a widened scanning head can prevent a key from being fully inserted without an otherwise equally dimensioned groove but without the undercut. On the other hand, an optional shoulder on the block tumbler, which may be present depending on the system or coding, can prevent the protection from being circumvented by a groove that is milled too wide and whose width corresponds to or exceeds the width of the scanning head. Such a shoulder can therefore cause the web that is formed above the undercut to be scanned by resting on the flat side of the key element. According to the terminology used here, a contact on the flat side also occurs when the key element has a shallow depression next to the entry groove and the shoulder rests on the surface of the key shaft in the area of this depression.

If at least the lateral cuts of the inlet groove are deeper in the coding area further away from the key tip than in the entry area, this enables the block lock to have a dual function. In addition to the insertion lock, which is caused by a missing or poorly designed (without undercut) inlet groove in the entry area, an individual mechanical coding can also be queried in the coding area. In particular, the inlet groove on the blank can have a central web. This can be left completely in the coding area when the key is individualized, or can be completely or partially removed, even to such an extent that a pronounced depression is formed in the middle of the inlet groove that is deeper than the undercut. Since the inlet groove is deeper in the area of the undercut than in the - generally shallow - entry area, suitable shapes of the scanning head can scan codes of different depths without the undercut being damaged together with the the scanning head engaging therein would prevent such scanning of different depths.

It is also possible for the entry groove to have a first depth in the entry area, a second, greater depth in an intermediate area and a third depth in an end area, whereby the third depth can correspond to the first depth or possibly (depending on the coding) the second depth, or which lies between the first and second depths. It is also possible for the third depth to be greater than the second depth. Depending on the design of the cylinder, the intermediate area and/or the end area can serve as the coding area scanned by the block tumbler. For example, with a reversible key, the intermediate area can be scanned on one side of the key and the end area on the other side. If only one of these areas is scanned, it is not immediately clear to the unauthorized key copier which of the areas is being scanned, so he must still try to copy the entire entry groove exactly.

In addition, by choosing different shapes of block tumblers at their radially inner end, scanning can take place at different parts in or near the coding area of the inlet groove: Firstly, there is the conventional option of scanning the depth of the inlet groove at its bottom - i.e. in the middle - using a correspondingly designed tip of the block tumbler. Secondly, there is the option of scanning a side flank of the inlet groove by making the scanning head relatively wide and flattened radially inward because it can be relatively wide due to the undercut. Thirdly, the shoulder of the block tumbler mentioned above, which interacts with the web above the undercut, can also scan a mechanical coding by either touching the web or not touching it depending on the depth of the inlet groove in the coding area. It is not possible to tell from the key itself what type of query is being carried out by the locking cylinder. This makes it more difficult for an unauthorized person to Key copiers follow this procedure because they can only successfully copy a key if they adopt all the characteristics of the copied key, including the shape and size of the undercut, which is difficult to copy.

The inlet groove can have a smaller width in the entry area than in the coding area. This has the potential advantage that the block locking device scans the undercut in the entry area using the scanning head mentioned, i.e. that even if the undercut is missing, an insertion lock is created in the entry area, even if the design of the inlet groove further back, in the coding area, allows scanning of different coding depths due to its greater width.

The side walls of the inlet groove can in particular have an undercut section in the form of a section which is inclined in section perpendicular to the key axis to the central plane, namely at an acute angle (α) away from the central plane, thus forming the undercut. The acute angle can be, for example, between 10° and 45°, in particular between 15° and 30°, for example between 20° and 25°, which enables production using milled oblique grooves.

Towards the inside, i.e. in the direction away from the flat side in which the inlet groove runs, an outer base section can be connected, which is inclined towards the central plane, also at a (second) acute angle β. The angle between the undercut section and the outer base section can be a right angle, which is why the second acute angle β=90°-α can be.

The inlet groove can in particular comprise two oblique grooves which run away from each other in a section perpendicular to the key axis in the direction away from the flat side. In other words, the inlet groove can comprise an axially running oblique groove on each side which extend away from each other in a section perpendicular to the key axis from the flat side. The undercut section mentioned can then be formed by a side wall of the corresponding oblique groove, the outer bottom section by its base.

Above the undercut section, i.e. towards the flat side, an outer vertical section can be connected to the undercut section, at least in one side wall. The outer vertical section is a section that is approximately parallel to the center plane of the inlet groove, i.e. parallel or possibly tapering very slightly (maximum 10° or maximum 5°) towards the center plane.

In at least one region, in particular in the middle, the inlet groove has in particular an inner bottom part which is perpendicular to the middle plane of the inlet groove and through which the middle plane passes.

The depth of the groove in the area of such a base section depends on the individual coding in the coding area of the finished key. On the key blank, the groove in the area of the base section is less deep than in the area of the lateral oblique grooves, i.e. there is a central web between the lateral oblique grooves. Depending on the coding selected, this may still be present on the key, possibly with a reduced height - or not.

The inlet groove will generally be symmetrical with respect to the centre plane in at least one region of its cross-section, which is consistent with the rotationally symmetrical design of the block tumbler. However, depending on the system selected, it can be provided that the pin axis and thus also the center plane of the inlet groove are not perpendicular to the flat side. In this case, the symmetry of the inlet groove with respect to its center plane is not complete, but only applies from a certain depth, because one side wall will then generally be higher than the other. This also occurs if, for example, with a center plane of the inlet groove perpendicular to the flat side, a shallow recess is made on one side of the inlet groove, which may serve other purposes.

The block code groove can be symmetrical with respect to the central plane, particularly from a certain depth, for example from the outer base section. The latter means that at least the outer base section and all sections lying deeper than this can be symmetrical with respect to the central plane.

The key element is a reversible key element, i.e. at least the area relevant for interaction with the locking cylinder, namely at least the key shaft, is symmetrical with respect to a rotation of 180° around the key axis.

The key element can have a run-in ramp on the front, towards the tip, which extends below the middle plane, ie the run-in ramp has a depth that is greater than half the thickness of the key shaft. This means that tumblers that extend relatively deep into the key channel can be used, and correspondingly deep coding holes are possible, which has a positive effect on the number of possible distinguishable permutations. If the key is a reversible key, such a run-in ramp is not possible across the entire width of the key tip for geometric reasons.

In embodiments, the entry ramp, the depth of which is greater than half the thickness of the key shank, is present at least at the lateral position (y-position) at which the row of tumblers is located, which also includes the block tumbler.

However, the lateral position of the inlet groove can also be where the inlet ramp does not have a depth that is more than half the depth of the key shank. In the case of a reversible key, due to its symmetry, the inlet ramp can only have a depth that is greater, i.e. half the thickness of the key shank, on one lateral side (e.g. only on the left or only on the right). The inlet ramp can also extend to the other side, where it has a depth that is correspondingly smaller than half the thickness of the key shank. In such embodiments, as an alternative to the arrangement where the inlet ramp is deeper than half the thickness of the key shank, the inlet groove can also be on the lateral side where the inlet ramp is less deep than half the thickness of the key shank. Of course, it is not impossible for an inlet groove of the type described here to be arranged on both lateral sides.

It is also possible to design the key in such a way that the entry ramp is no deeper than half the thickness of the key shaft.

In addition to the key element according to claim 1, the subject matter of the present invention also includes a locking cylinder according to claim 9 with the corresponding block tumbler. The locking cylinder is designed to interact with a flat key with at least two rows of coding holes parallel to the key axis. At least one of the rows of coding holes is collinear with the inlet groove, ie it comprises coding holes that are in the continuation of the Inlet groove are arranged to the rear, whereby optionally one or more of the coding holes can also be arranged in the inlet groove itself.

As is known per se, the locking cylinder has a locking cylinder stator and a locking cylinder rotor with a key channel which is arranged in the locking cylinder stator and can be rotated in a release position relative to it, as well as at least one row of locking and counter-locking pairs which are slidably mounted in pin holes in the locking cylinder rotor and in the locking cylinder stator and are pressed inwards towards the key channel by a spring. In addition, the locking cylinder has the block locking and the associated block counter-locking, in a row with at least one other of the locking and counter-locking pairs, for example in the rearmost position in the locking cylinder. The block locking has a neck radially inward towards the key channel and a scanning head adjoining it radially inward, the scanning head having a larger diameter than the neck and being designed to engage in the undercut inlet groove.

The total lengths of the block locking/counter locking pair are greater than the lengths of the other (regular) locking/counter locking pairs, resulting in the insertion lock described in this text.

The locking system according to the invention according to claim 11 comprises, in addition to at least one key element according to claim 8 - generally a plurality of keys and/or blanks - at least one locking cylinder according to claim 9. In addition to locking cylinders with the specially shaped block tumbler with neck and widened scanning head, a locking system can also comprise locking cylinders which do not have such a block tumbler, but a block tumbler with a conventional geometry tapering radially inwards or no block locking at all.

The possible features of the key element described in this text are optionally also features of the locking system and - mirrored accordingly - of the locking cylinder, and vice versa.

According to another aspect of the invention, there is a method according to claim 13 for producing a key element according to one of claims 1 to 8. The method runs as follows: In a first step, a key mold body is provided with a preparation groove that runs where the inlet groove is to be created and that extends axially backwards along the flat side from the key tip. Then, starting from the preparation groove, an axially extending oblique groove is introduced on both sides, for example milled, with the oblique grooves being inclined away from the center plane of the preparation groove by the (first) acute angle α discussed above. At least the oblique grooves and, for example, also the preparation groove are introduced in such a way that they have a non-constant depth along their axial extent, in particular by being less deep in the entry area than in the coding area further back.

After the oblique grooves have been made, the inlet groove has a central web between the oblique grooves. In this state, the key element can serve as a key blank and be delivered to system providers, for example. In a further step, coding holes can then be made to form the key. This step can include, for example, making a coding hole - depending on the coding - in the coding area of the inlet groove. In parallel to making the coding holes, the inlet groove can also be further processed. , for example in the entrance area, for example by partially or completely removing the central bar.

In this text, the orientation terms "radial", "radial-inside", "axial" etc. generally refer, unless otherwise stated, to the key axis, which in the locking system also corresponds to the locking cylinder axis when the key is inserted. "Front" refers to the position on the key or blank towards the key tip, and "back" is a position towards the bow of the key. In the locking cylinder, "front" is the position towards the insertion opening and "back" is the opposite, i.e. when the key is fully inserted, a front position on the key corresponds to a rear position in the locking cylinder. When describing the entry groove or coding holes in the key element, the terms "top" and "bottom" are sometimes used in this text. This refers to the situation that is also shown in the figures, in which the groove or hole extends downwards from the flat side on the top.

In relation to the lead-in groove, the «length» of the lead-in groove refers to its extension in the axial direction (or in the 'x' direction). The «depth» is the extension perpendicular to the flat side of the key (extension in the 'z' direction), and the «width» is the extension in the direction perpendicular to the key axis parallel to the flat side (extension in the 'y' direction).

Fig. 1

eine perspektivische Ansicht eines Schlüssels;

Fig. 2

eine perspektivische Ansicht eines Schliesszylinders mit Schlüssel, angeschnitten dargestellt;

Fig. 3

eine perspektivische Ansicht eines Schlüsselrohlings zur Herstellung eines Schlüssels nach Fig. 1;

Fig. 4

ein Detail der Ansicht aus Fig. 3;

Fig. 5-8

je die Ansicht der Blockzuhaltung und der Blockgegenzuhaltung während vier verschiedener Phasen beim Einschieben des Schlüssels in den Schliesszylinder, wobei Schlüssel und Schliesszylinder angeschnitten gezeichnet sind;

Fig. 9-11

je die Ansicht der Blockzuhaltung und der Blockgegenzuhaltung zusammen mit einem Detail des - entlang einer Ebene senkrecht zur Schlüsselachse geschnitten dargestellten - Schlüssels mit verschieden Ausgestaltungen der Blocknut im Codierbereich;

Fig. 12-14

je eine Ansicht sowie Schnittdarstellungen eines Schlüsselelements während dreier Phasen der Herstellung;

Fig. 15-16

je einen entlang einer Ebene parallel zur Schlüsselachse geschnittenen Schlüsselrohling, mit zwei verschiedenen Ausführungsformen der Einlaufnut;

Fig. 17-18

je die Ansicht einer Blockzuhaltung und einer zusammen mit dem - entlang einer Ebene senkrecht zur Schlüsselachse geschnitten dargestellten - zugehörigen Schlüssel in weiteren Ausführungsformen, wobei die Fig. 17 einen konventionellen Blockzuhaltungsstift darstellt;

Fig. 19

eine schematische Querschnittsdarstellung einer Einlaufnut im Codierbereich;

Fig. 20

eine zu Fig. 19 analoge schematische Querschnittdarstellung mit einer vergleichsweise tieferen Einlaufnut;

Fig. 21

eine Ansicht einer Spitze eines Schlüsselelements mit einer sich nach hinten aufweitenden Einlaufnut; und

Fig. 22

eine Ansicht der Schlüsselspitze des Schlüsselelements nach Fig. 21, zusammen mit einer Blockzuhaltung, die im Eingangsbereich in die Einlaufnut eingreift.

The subject matter of the invention is explained in more detail below using exemplary embodiments and the accompanying drawings. In the drawings, identical reference symbols designate identical or analogous elements. They show:

Fig.1

a perspective view of a key;

Fig.2

a perspective view of a locking cylinder with key, shown cut away;

Fig.3

a perspective view of a key blank for producing a key according to Fig.1 ;

Fig.4

a detail of the view Fig.3 ;

Fig. 5-8

each shows the view of the block tumbler and the block counter tumbler during four different phases when inserting the key into the locking cylinder, with the key and locking cylinder shown in section;

Fig. 9-11

each a view of the block tumbler and the block counter tumbler together with a detail of the key - shown cut along a plane perpendicular to the key axis - with different designs of the block groove in the coding area;

Fig. 12-14

one view and one cross-sectional view of a key element during three phases of production;

Fig. 15-16

one key blank cut along a plane parallel to the key axis, with two different designs of the inlet groove;

Fig. 17-18

each shows the view of a block tumbler and a key together with the associated key - shown cut along a plane perpendicular to the key axis - in further embodiments, wherein the Fig. 17 represents a conventional block tumbler pin;

Fig. 19

a schematic cross-sectional representation of an inlet groove in the coding area;

Fig. 20

one to Fig. 19 analogous schematic cross-sectional representation with a comparatively deeper inlet groove;

Fig. 21

a view of a tip of a key element with a rearward widening inlet groove; and

Fig. 22

a view of the key tip of the key element after Fig. 21 , together with a block lock that engages in the inlet groove in the entrance area.

Figure 1 shows an example of a key 1 with a key blade 11 and a key shaft 12. The key 1 is a flat key in which the key shaft is essentially non-square rectangular in cross-section perpendicular to a key axis 10, which defines two flat sides 21 parallel to one another and two narrow sides 22 with a smaller area than the flat sides 21. An edge 25 is formed between each of the flat sides 21 and the narrow sides 22. In the example shown, the narrow sides 22 are not completely flat, but slightly rounded.

Figure 1 also shows the Cartesian coordinate system used in this text, where the x-direction is parallel to the key axis and the z-direction is perpendicular to the flat sides 21.

On the key shaft 12, rows of coding holes 31 of various shapes and designs are provided, running parallel to the key axis 10.

The key shown is a reversible key, i.e. the key shaft is symmetrical with respect to a rotation of 180° around the key axis 10, and the codings on the front and rear flat sides 21 are correspondingly identical.

The key has a forward-sloping inlet ramp 24 towards the key tip 23, which allows the locking cylinder to have pins (e.g. tumblers) that scan the coding holes and extend further into the keyway than to the central plane, so that the coding holes can potentially have a depth greater than half the thickness of the key. This has a positive effect on the number of possible permutations.

Figure 2 shows the key 1 with a locking cylinder 101. The locking cylinder 101 has, in a manner known per se, a stator 103 and a rotor 104 mounted therein. A key channel 105 is formed on the rotor 104, into which the shaft of the key 1 is inserted. Fig.2 shows the configuration with the key fully inserted. If the key is coded appropriately, the rotor 104 can be rotated relative to the stator 103 about a lock cylinder axis parallel to the key axis. The rotation drives a bolt or other element, which in Fig.2 but is not shown.

The coding of the locking cylinder is achieved by the fact that pins serving as tumblers 111 are mounted in the rotor 104 with different tumbler lengths depending on the coding, whereby corresponding spring-loaded counter-tumblers 112 are present in the stator 103 (springs 113). These press the tumblers radially inwards against a stop. They are raised against the spring force by the inserted key. If the key is coded appropriately, as shown in Fig.2 the case, the parting line (ie the parting surface) between each tumbler 111 and its Counter-lock 112 with a separating surface between rotor 104 and stator 103, which is why the rotor from the Fig.2 shown position can be turned away. Also in Fig.2 illustrated are, firstly, the principle that the radially inner ends of the tumblers can be different in order to also query the shape of the coding holes 31 in the key, and, secondly, the principle that, with one exception discussed below, the sum of the lengths of the tumbler and counter-tumbler is identical for all pairs (or at least for groups of pairs).

These known principles of a locking cylinder structure and interaction with a key are supplemented according to the invention by the inlet groove 41 on the key and the block tumbler 141 and the corresponding block counter-tumbler 142, which in total can have a greater length than the regular tumbler-counter-tumbler pairs, on the locking cylinder 101.

Figure 3 shows a key blank 71 as used for the manufacture of a key according to Figure 1 can be used. The undercut groove 41 is present on the key blank, while the coding holes are only made on the key and can thus be used for individualization. The key can also have individualized features in the area of the groove 41 itself, which is described below.

The inlet groove extends along the flat side 21 from the key tip 23 in the axial direction. In Fig.3 one can see, firstly, that it is undercut and, secondly, that it has a non-constant depth in that, along its axial extension, it first runs at a higher level in an input region 51 and has a first, smaller depth, and then, in a coding region 52, runs lowered to a lower level and has a second, greater depth.

Figures 5-8 show the block tumbler 141 arranged at a rearmost position in the locking cylinder with block counter-tumbler 142 and spring 133 while the key 1 is inserted, whereby four different key positions are shown. in Fig.5 It is shown how the key tip 23 hits the radially inner end of the block tumbler 141, whereupon, when the key is further inserted, the block tumbler 141 is lifted by the inlet ramp 24 and pushed radially outward against the spring force.

Fig.6 shows the situation at the time when the block tumbler is in the entrance area. The block tumbler 141 is raised so far that the block counter tumbler 142 almost or completely abuts against the sleeve 105, which surrounds the lock cylinder stator 103 and on which the spring 103 rests. If the key did not have the inlet groove, or if it did not have the undercut, then the key could not reach this position at all, but would be blocked. This is because the sum of the radial lengths of the block tumbler 141 and the block counter tumbler 142 is greater than the corresponding sum of the lengths of the regular tumblers 111 and counter tumblers 112, which can be seen, for example, in Fig.2 also sees.

In Fig.7 you can see that the block tumbler is deflected slightly radially inward again by further inserting the key, as the inlet groove is lowered to the lower level.

Fig.8 shows the situation when the key 1 is fully inserted and the block tumbler 141 is in a coding position (a position in the coding range) relative to the key. As with the regular tumblers and counter-tumblers, If the key is suitable, the separating gap 145 will be aligned with the separating surface between the locking cylinder stator 103 and the locking cylinder rotor 104.

Figure 9 shows an embodiment of the block tumbler 141. Towards the radially inner end, this has a neck 152 adjoining a shaft 151 and a scanning head 153 adjoining this, which has a larger diameter than the neck 152 and can engage in the undercut. The scanning head forms a tapered area 154 towards the radially inner end and, in the embodiment shown, has a flat radially inner projection 155 which forms the tip of the block tumbler.

At the coding position, independent of the function of the insertion lock, which is caused by the total length of block locking device 141 and block counter locking device 142, various key-dependent codings are also possible. Fig.9 as well as Figure 10 show two corresponding variants.

When coding according to Fig.9 the inlet groove in the coding area and in particular at the coding position is designed in such a way that a recess is formed in the middle into which the scanning head 153 engages. The block tumbler can rest at its tip on the base of the inlet groove and/or with the tapered area 154 on a flank of the groove.

However, it can also be provided that the inlet groove in the coding area is milled less deeply, so that a central web 62 remains between the lateral oblique grooves 61 forming the undercut, on which the tip of the scanning head 153 rests, as shown in Fig.10 is visible. Different heights of this central bridge up to the situation according to Fig.9 (no central bar can be seen at all) form various mechanical codes, to which the length of the block tumbler 141 is adapted, which is also shown below in Fig. 19 is still shown.

In Fig.9 the pin axis 150 is also shown. The block tumbler 141 and the block counter tumbler, for example, like the regular tumblers and counter tumblers, are rotationally symmetrical (cylindrically symmetrical) with respect to this axis. Even if the block tumbler 141 does not belong to the key but to the locking cylinder, the orientation of the pin axis 150 is defined and recognizable on the key (and on the blank). The inlet groove defines the direction of the pin axis as a direction in the plane that is perpendicular to the key axis (the yz plane), and also in the plane with respect to which the inlet groove is at least partially symmetrical. The direction of the pin axis will generally be perpendicular to the bottom of the inlet groove in the region of its center and/or run exactly in the middle between flanks of the inlet groove and/or in the middle between oblique grooves 61 of the type described and/or in the middle between the undercut on both sides.

In the example of Fig.9 stands, as in Fig.10 and the following Fig. 11 , the pin axis 150 perpendicular to the flat side 21.

Figure 11 illustrates the possibility of adapting the shape of the scanning head 153. The scanning head 153 is flattened at the radially inner end, so that the tapered area 154 is shortened, the radially inner projection is also absent and an enlarged end surface 156 is created accordingly. The scanning therefore takes place laterally through the tapered area 154, outside the area that can be detected by a scanning tool that scans the key shaft from the flat side in order to copy the key (see the dotted line in Fig. 11 ).

If someone tries to copy the key using conventional milling tools and takes into account the width of the scanning head 153 the run-in groove milled out over its entire width, as in Fig. 11 indicated by the dashed line, then this will lead to failure because the block tumbler moves too far radially inward until the end face 156 rests against the base of the groove that is milled too wide, which would lead to negative locking in the configuration shown. It is not possible to tell from the key to what other depth such a wide groove would have to be milled in order to successfully unlock the lock cylinder.

The combination of a such as Fig. 11 designed scanning head with the undercut of the inlet groove 41 is therefore an additional security feature and represents copy protection.

• Variationen der Länge des Halses 152. Ein verkürzter Hals 152 kann bewirken, dass die Blockzuhaltung schon mit der Schulter 157 zwischen dem Schaft 151 und dem Hals 152 im Bereich des Stegs 158 oberhalb des Hinterschnitts auf der Flachseite 21 des Schlüsselschafts aufsteht. Wird die Nut durch den unbefugten Kopierer zu breit gefräst, um den Abtastkopf aufzunehmen ohne einen Hinterschnitt vorzusehen, kann ein solches Aufstehen nicht stattfinden, und die Blockzuhaltung gelangt ebenfalls zu weit nach radial-innen, was eine negative Versperrung bewirken wird.
• Auch Kombinationen sind denkbar. Insgesamt gibt es eine Mehrzahl von Möglichkeiten, wo die Einlaufnut oder deren Umgebung abgetastet werden kann, und am Schlüssel selbst ist nicht erkennbar, wo die Blockzuhaltung das effektiv macht. Daher kann ein Schlüssel nicht zuverlässig kopiert werden, indem nur einzelne Merkmale davon kopiert werden.

Other options include:

• Variations in the length of the neck 152. A shortened neck 152 can cause the block tumbler to stand up with the shoulder 157 between the shaft 151 and the neck 152 in the area of the web 158 above the undercut on the flat side 21 of the key shaft. If the groove is milled too wide by the unauthorized copier to accommodate the scanning head without providing an undercut, such standing up cannot take place and the block tumbler also moves too far radially inward, which will cause a negative blocking.
• Combinations are also conceivable. Overall, there are a number of possibilities where the entry groove or its surroundings can be scanned, and it is not clear from the key itself where the block tumbler effectively does this. Therefore, a key cannot be reliably copied by copying only individual features of it.

Figures 12 to 14 show steps in the process of manufacturing a key. In the figures, sections through levels II, II-II and III-III are shown on the right, which are shown in the top views on the left in the figures.

In a Fig. 12 In the step shown, a key mold body 81 is first provided with a preparation groove 91 that runs axially along the flat side from the key tip in the area in which the inlet groove is to be created. The preparation groove 91 can already have a smaller depth in the entry area 51 than in the coding area 52. It serves to prepare and simplify the creation of the undercut inlet groove.

Fig. 13 shows the blank 71 as it was created after the inlet groove was created. By milling with a milling tool whose axis of rotation is inclined to the flat side, the oblique grooves 61 are created in addition to the preparation groove and from this, between which a central web 62 remains. You can see in Fig. 13 It is also clear that the inlet groove 41 thus created is lowered towards the rear, towards the coding area, i.e. it is deeper, both in the area of the central web and, in the embodiment of Fig. 13 particularly pronounced in the area of the oblique grooves 61.

In Fig. 13 The blank is finished in the state shown. In this state it can be sold as a product to specialist shops that are authorized to customize it.

The finished, customized key can be seen in detail in Fig. 14 . During the individualization step, the coding holes 31 are made, of which Fig. 14 only some are shown, and which can have different depths and different shapes. On the other hand, depending on the Individualization the inlet groove 41 is modified. In the example of Fig. 14 This is done by partially removing the central web 62 in the coding area 41 (see, for example, section III of Fig. 14 ) to the depth of a desired coding as well as by optional post-processing in the input area (section I of fig. 14 ).

In Figure 14 the optional feature of a non-undercut groove extension 94 of the inlet groove is also shown, which represents a further coding. Optionally, the locking-counter-locking pair arranged in the same row adjacent to the block locking (or, in the case of a reversible key, the locking-counter-locking pair at the corresponding position of the locking cylinder rotated by 180°) can also be extended in order to also scan the groove extension 94 and, if necessary, to have a corresponding blocking effect. One of the coding holes 31 is located in the groove extension in the example shown.

Another optional feature that can be found in Fig. 14 is another inlet groove 95 which leads to a first coding position.

The inlet groove 41 can be coded not only by individualization (by machining the central web 62), but also by different depths of the oblique grooves 61, which in Figures 15 and 16 These figures each show a blank 71 with a flatter inlet groove 41 ( Fig. 15 ) and with a deeper inlet groove 41 ( Fig. 16 ). In this way, for example, a distinction can be made between different incompatible locking systems at the "blank" level. For example, a locking cylinder can be designed in such a way that a key with the flatter entry groove cannot be inserted at all by choosing a corresponding total length of block tumbler and block counter-tumbler. On the other hand, a - different - locking cylinder can also be designed in such a way that it There cannot be a key with the deeper entry groove that opens this locking cylinder - e.g. through a very flat coding in the area of the entry groove (short block locking) - by using the interaction between the scanning head and the undercut.

Based on the design of Figure 17 Firstly (as in Fig. 18 below) illustrates that the pin axis 150 does not necessarily have to be perpendicular to the flat side 21. Rather, it can - as is known per se - be in the yz plane, i.e. the plane perpendicular to the key and cylinder axis - at an angle to the normal to the flat side. This optionally applies both to the block tumbler 141 and to the regular tumbler pins in the corresponding tumbler row. The undercut of the inlet groove also applies in these embodiments with respect to the pin axis 150. In these embodiments too, the inlet groove can be symmetrical with respect to a plane that goes through the pin axis 150 and is parallel to the key axis, i.e. in Fig. 17 perpendicular to the drawing plane.

The option that the pin axis is at an angle other than 0° to the normal to the flat side 21 applies to all embodiments and features of the concepts described in this text. It is independent of the specific features of the embodiments of Figs. 17 and 18 .

In Fig. 17 Furthermore, the possibility is also shown that a conventional tumbler pin, not part of the invention, without the widened scanning head can be used as the block tumbler pin 141. The pin tip with the radially inner projection 155 then directly adjoins the neck 152. Such a block tumbler pin 141 therefore does not query the undercut and would also work with keys that have a non-undercut entry groove if whose width is adapted accordingly. In a system with a plurality of locking cylinders, however, it may be an option to use cylinders according to the invention with an expanded scanning head on the block tumbler and additionally those without this scanning head.

Also in Fig. 17 illustrates the possibility of having a shoulder 157 of the block tumbler on the key surface, ie on the flat side 21. In corresponding embodiments, it is not the depth of the inlet groove - e.g. in the coding area - that is scanned, but only its presence.

The latter (scanning only the key surface in lock cylinder configurations) is also an option in embodiments with the expanded scanning head 153, which in Figure 18 is shown. In this embodiment, in addition to the presence of the inlet groove, the undercut is also scanned. The width of the shaft 151 in the area of the shoulder 157 can be similar to the width of the scanning head. Therefore, depending on the shape and dimensions of the scanning head, a key with an inlet groove that is wide enough to accommodate the scanning head would not work, since the block tumbler would then not be able to stand up with the shoulder 157 on the flat side and the block tumbler would fall too far radially inward. The possibility of scanning on the key surface is therefore also a potential security feature in combination with the undercut.

The block tumblers 141 of the Figures 17 and 18 also differ in the shape of the shaft 151 from that of the embodiments described above, in particular in the steps of the shaft. However, this has no influence on the other features described in this text.

In Figure 19 a schematic cross-section through the inlet groove 41 in the coding area is drawn. The thick line shows the inlet groove with a specific, first coding (C1), which corresponds to the longest block tumbler. In the example shown, the center plane 160 of the inlet groove - in which the pin axis of the block tumbler lies - is inclined to the normal to the flat side 21.

Characteristic of the inlet groove of keys according to the invention and also key blanks is an undercut section 162 which, coming from the flat side and into the depth of the inlet groove, is inclined away from the central plane, which creates the undercut. The undercut section is inclined at an acute angle α to the central plane 160, wherein the angle α can in particular be between 10° and 45°, for example between 15° and 30°.

Towards the flat side, the undercut section can be connected to an outer vertical section 161, which can also be formed on only one side in the case of inlet grooves inclined to the flat side normal, as in the example shown, in Fig. 19 on the left.

In the direction away from the flat side 21, the undercut section 162 is adjoined by an outer base section 163 which is inclined towards the central plane 160, in particular at a second acute angle β. In many embodiments, the second acute angle β is greater than the first acute angle α. In particular, the outer base section 163 can be formed at a right angle to the undercut section 162. Then β=90°-α. Such an outer base section can be manufactured in a simple manner by setting a milling tool at an angle α to the central plane 160 and milling oblique grooves, as described above with reference to Fig. 13 was declared.

Depending on the coding, an inner vertical section 164 and an inward-tapering section 165 may follow the outer base section.

The dashed lines outline alternative cross-sections that result from a second coding (C2) and a fourth coding (C4); a third coding between the second and fourth coding is not shown for reasons of clarity. It can be seen from these dashed lines that the inner vertical section 164 does not always result, and that a counter gradient can also result from the inward-tapering section 165.

Common to all codes is an inner base portion 166, the position of which determines the code in embodiments in which the code is scanned by the tip of the block tumbler. The center plane 160 runs through the inner base portion 166 and generally forms its central vertical plane.

In Fig. 19 Reference numeral 170 designates the undercut, delimited by the respective dotted line.

In Fig. 19 one can also see that the inlet groove is symmetrical with respect to the central plane 160, except for the fact that the side wall is not raised to the same height on both sides, due to the inclined position of the central plane (160); in other embodiments, e.g. in Fig. 17 and Fig. 18 , a shallow recess next to the inlet groove can also influence how far the side wall extends. If the inlet groove is symmetrical with respect to the center plane, in this text this may mean that the symmetry only exists from a certain depth, measured along the center plane.

Figure 20 shows a Fig. 19 analog representation of a cross section through an inlet groove 41 in the coding area. The inlet groove 41 of the embodiment of Fig. 20 differs from that of Fig. 19 because the undercut is deeper, i.e. during production the lateral oblique grooves were milled deeper into the key blank. This results in a qualitatively slightly different course of the side wall of the inlet groove, since even in the embodiment with the deepest, first coding there is no inner vertical section. Instead, small webs 169 can be present next to the outer base section 163 towards the central plane, which are formed between the milling forming the oblique grooves and the inner base section 166 due to the manufacturing process. In addition, in the embodiment shown there is an outer vertical section 161 on both sides, although the central plane 160 of the inlet groove is inclined to the flat side normal.

Figures 21 and 22 illustrate, using a section of a key 1 shown in view, the possibility that the inlet groove 41 can have a smaller width (first width bi) on the front side in the entry area than in the coding area (second width b ₂ ). The width of the inlet groove at a certain axial position is measured in the depth at which the inlet groove is widest in the cross section at this axial point, ie in the depth of the undercut. This means that the undercut of the inlet groove 41 can be interrogated in the entry area, as the scanning head 153 would prevent insertion if the undercut were not present, which in Fig. 22 is clearly visible. Fig. 22 illustrates that the scanning head practically completely fills the undercut in the entry area, as the inlet groove is less wide there. In the coding area, the larger second width b ₂ of the inlet groove enables different codings, ie the scanning head can be arranged at different depths relative to the parts that form the undercut.

Claims (14)

1. A key element (1, 71) having a key bow (11) and a key shank (12), which extends along a key axis (10) from the key bow (11) to a front-side key tip (23) with two mutually parallel flat sides (21) and two mutually opposite narrow sides (22), having an inlet groove (41), which extends in one of the flat sides from the key tip parallel to the key axis (10) and which has a non-constant depth along its axial extension, wherein the inlet groove is undercut, characterised in that the key element (1, 71) is a reversible key element in that the key shank (12) is symmetrical with respect to a rotation of 180° around the key axis.
2. The key element according to claim 1, wherein the inlet groove has a first depth in an entry region (51) and a second, greater depth in a coding region (52) further away from the key tip, and wherein, for example, an undercut (170) formed by the inlet groove runs at a greater depth in the coding region than in the entry region.
3. The key element according to claim 2, wherein the inlet groove (41) has a smaller width in the entry region (51) than in the coding region (52).
4. The key element according to one of the preceding claims, wherein a side wall of the inlet groove (41) has an undercut part (162) at at least one position in a section perpendicular to the key axis, which is inclined from the flat side (21) away from a centre plane (160) of the inlet groove (41), at an acute angle (α) to the centre plane (160), wherein the acute angle (α) to the centre plane (160) of the inlet groove (41) is, for example, between 10° and 45°.
5. The key element according to claim 4, wherein an outer base part (163) adjoins the undercut part in the direction away from the flat side (21), wherein the outer base part (163) is inclined at a second acute angle (β) towards the centre plane (160) of the inlet groove (41), wherein, for example, the outer base part (163) forms a right angle with the undercut part (162).
6. The key element according to one of the preceding claims, which is a key blank (71) for producing a flat key (1) by providing individualised coding holes (31).
7. The key element according to claim 6, wherein the inlet groove (41) has two oblique grooves (61) and a central web (62) between the oblique grooves.
8. The key element according to one of claims 1 to 5, which is a flat key and has on the flat side at least two rows of coding bores (31) parallel to the key axis (10), of which one row is arranged collinearly with the inlet groove (41).
9. A lock cylinder for a key element according to claim 8, with a lock cylinder stator (103) and a lock cylinder rotor (104) with a key channel arranged in the lock cylinder stator and rotatable relative thereto in a release position, as well as at least one row of tumbler (111)/counter-tumbler (112) pairs which are displaceably mounted in pin holes in the lock cylinder rotor and in the lock cylinder stator and are pressed inwards in the direction of the key channel by a spring (113), characterised by a block tumbler (141) and an associated block counter-tumbler (142), wherein the block tumbler (141) has a neck (152) radially inwards towards the key channel and a scanning head (153) adjoining it radially inwards, wherein the scanning head has a larger diameter than the neck and is designed to engage into the undercut inlet groove (41).
10. The lock cylinder according to claim 9, wherein a sum of the lengths of the block tumbler (141) and the block counter-tumbler is greater than a sum of the lengths of the tumbler (111)/counter-tumbler (112) pairs.
11. A locking system, having at least one key element according to claim 8 and at least one lock cylinder according to claim 9, wherein the block tumbler (141) is arranged such that when the key element is inserted into the key channel it is first raised and then the scanning head (153) is guided in the inlet groove (41).
12. The locking system according to claim 11, wherein the inlet groove (41) is designed such that the block tumbler (141) is first raised into a first radially outer position when the key element is inserted and is then displaced radially inwards into a second position, and/or wherein the scanning head (53) is located in a coding region (52) of the inlet groove when the key element is completely inserted into the key channel, wherein in particular a radially inner tip of the scanning head rests on a bottom of the inlet groove when the scanning head is in the coding region (52), wherein in particular a laterally radially inwards tapering region (154) of the scanning head (153) rests on an inwards tapering part (165) of the inlet groove (41) forming a lateral flank when the scanning head is located in the coding region (52), and/or wherein a shoulder (157) of the block tumbler formed radially outside the neck (152) rests on the flat side (21) of the key element when the scanning head is located in the coding region (52).
13. A method for producing a key element (1, 71) according to one of claims 1 to 8, comprising the steps:

    - providing a key moulded body (81) having a key shank with two parallel flat sides and two narrow sides between the flat sides, as well as having a key bow, wherein the key moulded body (81) forms a key tip on the front side;

    - providing a preparation groove (92) extending axially rearwardly from the key tip along one of the flat sides;

    - providing, on both sides, an axially running oblique groove (61), which extends proceeding from the preparation groove (92) away from a central plane of the preparation groove obliquely into the depth of the key shank, whereby the inlet groove with an undercut results from the preparation groove (92) with the two oblique grooves (61), wherein the oblique grooves (61) and/or the preparation groove (92) are provided such that they have a non-constant depth, and after the oblique grooves (61) have been introduced, the inlet groove between the oblique grooves (61) has a central web (62).
14. The method according to claim 13, wherein coding bores (31) are provided to produce a flat key and the central web (62) between the oblique grooves (61) is at least partially removed.

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