Key element, locking cylinder, locking system, and method

Abstract

Key Element, Locking Cylinder, Locking System, and Method A flat key (1) comprises a key head and a key shank extending along a key axis from said key head to a front key tip and having two parallel flat faces and two mutually opposing narrow faces. An entry groove is provided in at least one of said flat faces extending from said key tip parallel to said key axis and having a non-constant depth along its axial extent. The entry groove may have a first depth, particularly in the entry area, and a second, larger depth in a coding area remote from said key tip. According to the invention, the entry groove is undercut so that an extended sensing head of a block tumbler 141 can engage therein.

Description

[Technical field]

[0001] The present invention relates to the field of mechanical locking systems, in particular to a locking system having a locking cylinder and a key element fitted thereto, as well as to a key element, a locking cylinder for such a locking system, and a method for manufacturing the key element. [Background technology]

[0002] As used herein, the term "key element" refers to mechanical keys and key blanks for manufacturing such keys.

[0003] A locking cylinder has a stator (sometimes called a "cylinder housing") that is non-rotatably fixed to the lock, and a rotor (sometimes called a "cylinder core") that is rotatable about the axis of the locking cylinder when a matching key is inserted. Rotation of the rotor moves an output means, which is used to actuate a bolt or other means associated with the desired function of the locking cylinder.

[0004] Many mechanical locking cylinders have a tumbler / counter-tumbler pair that senses the mechanical coding of the inserted key. In each such pair, one tumbler is guided in a rotor hole, and an aligned stator hole in the base position guides the corresponding counter-tumbler. The tumbler / counter-tumbler pair is pressed radially inward by a spring so that the tumbler protrudes into the key channel. When a key that fits the locking cylinder is pressed into the locking cylinder, the tumbler is positioned so that the separation joint (i.e., generally a separation surface, line, or point) formed between the tumbler and counter-tumbler coincides with the separation joint (i.e., a separation surface / shear surface) between the rotor and the stator, at which point the rotor can rotate away from the base position.

[0005] The locking systems of interest in the present context have a tumbler / counter-tumbler pair arranged at an angle to a flat surface, with a corresponding mechanical coding formed in the flat surface by means of blind holes (additional mechanical coding, for example in the form of narrowing and / or profiling, is of course not excluded), which distinguishes them from locking systems in which the tumblers are arranged parallel to the flat surface and engage in a serrated control groove in the flat surface via a protrusion transverse to the tumbler axis.

[0006] Publications WO01 / 77466 and WO2014 / 032191 each present a locking system in which an extending tumbler / counter-tumbler pair is arranged on the locking cylinder in the 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 a suitable cross section for the corresponding tumbler along the flat face of the key, away from the tip of the key. By this approach, an additional security feature is created and the number of possible permutations (which should always be as large as possible) is simultaneously increased or at least not reduced compared to the prior art.

[0007] U.S. Patent No. 5,819,566 discloses a cylinder lock with a resiliently biased secondary locking pin projecting into a key channel, the secondary locking pin having a first end shaped to partially define an expansion pin and a second end that engages in a locking recess in the lock housing. A cooperating key has a key shank with a longitudinal slot shaped to engage the first end of the secondary locking pin, the depth profile of the slot increasing from an initial engagement depth to a functional depth. When the key is inserted, an axial force acting on the head of the secondary locking pin is generated to retract the second end of the bolt from the locking recess in the shell.

[0008] There is a constant need in the locking technology to further increase the cloning resistance without requiring too much space on the key for new security features and without significantly complicating the production of blank keys and series of keys.The object of the present invention is therefore to provide a key element, a locking cylinder and a locking system, as well as a method for producing a key element, which meets this need and in particular allows for increased cloning resistance. Summary of the Invention

[0009] According to one aspect, the invention relates to a key element, i.e. a flat key or a blank for producing a flat key, having a key shank with two parallel flat faces and two mutually opposing narrow faces. The key element has an entry groove, which extends from said key tip parallel to the key axis in one of the flat faces and has a non-constant depth along its axial extent. The entry groove can have a first depth, especially in the entry area, and a second, larger depth in the coding area, away from the key tip.

[0010] According to the invention, the inlet groove is undercut.

[0011] Due to their design, the entry grooves are generally profiled in cross-section perpendicular to the key axis, i.e. the depth of the groove is not necessarily constant across its width. Thus, the depth of the entry groove at a particular axial location is defined as the average depth across the cross-section at that axial location. The non-constant depth feature applies to depths according to this definition. Moreover, it may be specifically applied to such undercuts.

[0012] The inlet groove runs parallel to the key axis, i.e. its (centre) position in a direction parallel to the plane of the flat surface and perpendicular to the key axis (y coordinate) is constant along its axial extent. This is necessary because the block tumbler contacts the flat surface perpendicularly or at another angle and is not guided parallel to the flat surface as is the case with tumblers which interact with, for example, a sawtooth control groove. The constant position in the plane of the flat surface (y position) does not exclude the possibility that the cross section of the inlet groove may vary along its length, including the possibility that it widens or narrows along its length. An example of widening towards the rear is described below.

[0013] In the locking cylinder associated with the key element, particularly in the rearmost position in the row of tumbler / counter-tumbler pairs, there is a block tumbler whose overall length (possibly depending on the coding) exceeds the overall length of the other normal tumbler / counter-tumbler pairs, so that the key can only be fully inserted into the locking cylinder if it has an entry groove of sufficient depth.

[0014] The block tumbler may have a sensing head extending radially outward from the neck so that, among other things, undercuts in the entry groove may be sensed. If the groove is of the correct width but does not have an undercut, the key may not be fully inserted.

[0015] Like normal tumblers, block tumblers can be designed to be cylindrically symmetric (rotationally symmetric about rotation through any angle) about the pin axis. The "undercut" is defined with respect to a direction corresponding to the direction of the pin axis that senses the key at the entry groove. This can be perpendicular to the flat surface or can be at an angle to the normal to the flat surface. Even if the sensing pin (i.e. the block tumbler) belongs to the locking cylinder and not to the key, the orientation of the pin axis is defined and recognizable in the key element in that the entry groove is symmetric over at least a part of its cross section with respect to a central plane that is parallel to the key axis and passes through the pin axis.

[0016] In other words, the undercut is specifically an undercut in a direction perpendicular to the key axis and parallel to the central plane of the entry groove, which generally corresponds to the direction of the pin axis, meaning that the undercut would prevent a pin having an extension (e.g. a sensing head as described below) that engages in the undercut from being hypothetically pulled radially outwards.

[0017] The undercut can be formed on both sides of the inlet groove, or optionally only on one side. Additionally or alternatively, it may be present on at least one side in a direction perpendicular to the flat surface. This is an option even if the central plane of the inlet groove is not perpendicular to the flat surface. The feature of the undercut also being present in a direction perpendicular to the flat surface is generally self-evident in the approach described herein. It has the advantage that the area of ​​the inlet groove is in the so-called shadow of the optical scanner, i.e. the optical scanner cannot detect the inlet groove.

[0018] When the groove is undercut, at least one transverse cut is made in the lateral direction; in the exemplary embodiment of the invention considered here, in particular two cuts are made, arranged symmetrically with respect to the central plane of the inlet groove.

[0019] The configuration of the entry groove as a groove with an undercut provides important advantages. First, such undercuts cannot be easily detected quantitatively and accurately with conventional detection tools or conventional optical scanners used by key duplicators. This alone makes duplication more difficult. Second, in order to produce the undercuts, a specially configured tool, e.g. a milling cutter, must also be provided that produces the inclined grooves for forming the transverse cuts at angles to each other and to the central plane. Even if the tools are configured such that such inclined grooves can be efficiently produced and the production costs of the blank key do not increase significantly, they still have to be specially configured for this purpose, something that unauthorized key duplicators generally do not have the means to do. Third, the undercut entry groove potentially provides a double security. On the one hand, as mentioned, the widened detection head can prevent the key from being fully inserted even without the undercut, without the otherwise equally dimensioned grooves. On the other hand, an optional shoulder on the block tumbler, which may be present depending on the system or coding, can prevent the circumvention of protection by a groove milled too widely, the width of which corresponds to or exceeds the width of the detection head. Such a shoulder can thus make it possible to detect the web formed above the undercut by abutting against a flat surface of the key element. According to the terminology used here, abutment against a flat surface also occurs when the key element has a shallow recess next to the entry groove and a shoulder in the area of ​​this recess abuts against the surface of the key shank.

[0020] If at least the lateral cut of the entrance groove in the coding area away from the key tip is deeper than in the entry area, this allows a double function of the block tumbler. In addition to the insertion lock, which occurs due to the absence or poor construction of the entrance groove in the entry area (no undercut), the individual mechanical coding can also be detected in the coding area. It may in particular be that the entrance groove on the blank has a central web. When customizing the key in the coding area, this may be left completely or may even be partially or completely removed to the extent that a noticeable depression is formed in the middle of the entrance groove, which is deeper than the undercut. Since the entrance groove is deeper in the area of ​​the undercut than in the entry area, which is generally shallow, codings of different depths can be detected by a suitable shaped detection head, and the undercut does not prevent the detection of such different depths with the detection head engaging it.

[0021] It is also possible for the entry channel to have a first depth in the entry area, a larger second depth in the middle area, and a third depth in the end area, the third depth corresponding to the first depth or possibly the second depth (depending on the coding) or a depth between the first and second depths. It is also possible that the third depth is larger than the second depth. Depending on the configuration of the cylinder, the middle area and / or the end area can serve as the coding area sensed by the block tumbler. For example, in the case of a reversible key, the middle area may be sensed on one side of the key and the end area on the other side. If only one of these areas is sensed, it is not immediately clear to an unauthorized key duplicator which area is sensed, so that they still have to precisely copy the entire entry channel.

[0022] Moreover, by choosing a block tumbler with a different shape at its radially inner end, it is possible for the detection to take place in different parts in or near the coding area of ​​the entry groove. Firstly, there is the conventional possibility of detecting the depth of the entry groove at its bottom, i.e. in the middle, by means of a suitably configured tip of the block tumbler. Secondly, since the detection head can be relatively wide due to the undercut, it is possible to detect the lateral side of the entry groove by flattening it relatively wide radially inwards. Thirdly, the shoulder of the block tumbler mentioned above, which interacts with the web above the undercut, can also detect the mechanical coding, either by abutting the web or not abutting it, depending on the depth of the entry groove in the coding area. It is not possible to identify from the key itself which type of detection is performed by the locking cylinder. This makes it more difficult for unauthorized key duplicators to successfully copy a key, since they can only do so if they match all the features of the key to be copied, including the shape and size of the undercut, which are difficult to copy.

[0023] The inlet groove can have a smaller width in the entry area than in the coding area, which has the potential advantage that even if the configuration of the inlet groove in the coding area further back allows detection of a different coding depth due to its larger width, the block tumbler detects the undercut in the entry area using the mentioned detection head, i.e. even if there is no undercut, an insertion lock is created in the entry area.

[0024] The side walls of the inlet groove can in particular have an undercut portion inclined towards the central plane in a cross section perpendicular to the key axis, i.e. forming an acute angle (α) away from the central plane, thus forming an undercut, whereby the acute angle can be, for example, between 10° and 45°, in particular between 15° and 30°, for example between 20° and 25°, which allows the production of a milled inclined groove.

[0025] The outer bottom portion may be contiguous inwardly, i.e., away from the planar surface through which the inlet groove passes, and may be inclined toward the central plane at a (second) acute angle β. The angle between the undercut portion and the outer bottom portion may be a right angle, such that the second acute angle β=90°-α.

[0026] The inlet groove may in particular have, on each of its two sides, an axially extending oblique groove which extends away from the flat surface in a cross section perpendicular to the key axis, the mentioned undercut portion being in this case formed by the side wall of the corresponding oblique groove, the outer bottom portion being formed by its base.

[0027] Above the undercut portion, i.e. towards the flat surface, an outer vertical portion may adjoin the undercut portion on at least one side wall, the outer vertical portion being approximately parallel to the central plane of the inlet groove, i.e. parallel or possibly very slightly tapered (at most 10° or at most 5°) towards the central plane.

[0028] In the center, the entry groove has a bottom portion perpendicular to the central plane. The depth of the entry groove in the bottom portion of the finished key varies depending on the individual coding in the coding area. In the blank key, the entry groove in the area of ​​the bottom portion is not as deep as in the area of ​​the lateral oblique grooves, i.e. there is a central web between the lateral oblique grooves. Depending on the selected coding, this may or may not still be present in the key, possibly with a reduced height.

[0029] The inlet groove is generally symmetrical with respect to the central plane in at least one region of its cross section, which is complemented by the rotationally symmetrical configuration of the block tumbler around the pin axis. However, depending on the selected system, it can be provided that the pin axis, and thus also the central plane of the inlet groove, is not perpendicular to the flat surface. In this case, the symmetry of the inlet groove with respect to the central plane applies not completely but only from a certain depth, since in this case one side wall is generally higher than the other. This also occurs, for example, if a shallow recess is provided on one side of the inlet groove in the central plane of the inlet groove perpendicular to the flat surface, which may serve other purposes.

[0030] The block code groove may be symmetrical about the central plane, particularly from the outer bottom portion, meaning that at least the outer bottom portion and all portions deeper than this may be symmetrical about the central plane.

[0031] The key element is a reversible key element, i.e. at least the area involved in the interaction with the locking cylinder, i.e. at least the key shank, is symmetrical with respect to a rotation of 180° about the key axis.

[0032] The key element may have an entrance ramp on the front side towards the tip, extending below the central plane, i.e. the entrance ramp has a depth greater than half the thickness of the key shank. This allows the use of tumblers that protrude relatively deep into the key channel and allow correspondingly deep coding holes, which has a positive effect on the number of different permutations possible. If the key is a reversible key, such an entrance ramp is not possible over the entire width of the key tip for reasons of shape.

[0033] In an embodiment, an entrance ramp with a depth greater than half the thickness of the key shank is present at least at the lateral location (y location) where the row of tumblers, including the block tumblers, is located.

[0034] However, the lateral position of the entry groove can also be where the entry ramp has a depth not greater than half the depth of the key shank. Due to the symmetry of the reversible key, the entry ramp can have a depth greater than half the thickness of the key shank only on one lateral side (e.g. only on the left or only on the right). The entry ramp can also extend to the other side, but there it has a depth correspondingly less than half the thickness of the key shank. In such an embodiment, as an alternative to the arrangement where the entry ramp is deeper than half the thickness of the key shank, the entry groove can also be on the lateral side, where the entry ramp is not deeper than half the thickness of the key shank. Of course, it is not excluded that entry grooves of the type described here are arranged on both lateral sides.

[0035] It is also possible to construct the key so that the entrance ramp is no deeper than half the thickness of the key shank.

[0036] In addition to the key element (key, in particular a flat reversible key or blank), a locking cylinder with a corresponding block tumbler is also part of the subject matter of the invention. The locking cylinder is configured to interact with flat keys of the type described herein, in particular with flat keys having 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 entry groove, i.e. it has a coding hole arranged following the entry groove towards the rear, and optionally it is also possible that one or more coding holes are arranged in the entry groove itself.

[0037] As known per se, the locking cylinder has a locking cylinder stator and a locking cylinder rotor, a key channel arranged on the locking cylinder stator and rotatable relative thereto in the release position, and at least one row of tumbler / counter-tumbler pairs slidably mounted in pinholes in the locking cylinder rotor and the locking cylinder stator and pressed inwardly towards the key channel by springs. Furthermore, the locking cylinder has a row of block tumblers and associated block counter-tumblers, for example at the rearmost position of the locking cylinder, together with at least one other tumbler / counter-tumbler pair. The block tumblers have a neck radially inwardly towards the key channel and a sensing head radially inwardly adjacent thereto, the sensing head having a diameter larger than the neck and designed to engage in an undercut entry groove.

[0038] The overall length of the block tumbler / counter tumbler pair is greater than the length of other (normal) tumbler / counter tumbler pairs, resulting in the insertion lock described herein.

[0039] The locking system according to the invention has at least one locking cylinder in addition to at least one key element, typically a number of keys and / or blanks. In addition to locking cylinders with specially shaped block tumblers with necks and enlarged sensing heads, the locking system can also have locking cylinders without such block tumblers, but rather with conventionally shaped block tumblers tapered radially inwards, or no block tumblers at all.

[0040] Possible features of the key elements described herein are optionally also features of the locking system and of the locking cylinder, mirrored accordingly, and vice versa.

[0041] The method for manufacturing the key element proceeds in particular as follows: in a first step, the key moulding body is provided with a preparation groove which runs axially backwards from the key tip along a flat surface through the place where the entry groove is to be made. Then, proceeding from the preparation groove, on both sides, axially extending oblique grooves are introduced, for example milled, which oblique grooves are inclined away from the central plane of the preparation groove at the (first) acute angle α discussed above. At least the oblique grooves and, for example, also the preparation grooves are introduced, so that they have a non-constant depth along their axial extent, in particular in the entry region, by being less deep than in the coding region further back.

[0042] After the inclined grooves have been introduced, the entry groove generally has a central web between the inclined grooves. In this state, the key element can serve as a blank key and can be delivered, for example, to the system provider. In a further step, coding holes can then be punched to form the key. Depending on the coding, this step can also include punching coding holes, for example, in the coding region of the entry groove. In parallel with the punching of the coding holes, for example in the entry region, it is also possible for the entry groove to be further processed, for example by partially or completely removing the central web.

[0043] In this specification, the orientation terms "radial", "radially inward", "axial" etc. generally refer to the key axis, unless otherwise stated, which in a locking system also corresponds to the axis of the locking cylinder when the key is inserted. "Front" refers to the position towards the key tip on the key or blank and "rear" is the position towards the key head. In a locking cylinder, "front" is the position towards the insertion opening and "rear" is the opposite, i.e. when the key is fully inserted, the front position of the key corresponds to the rear position of the locking cylinder. When describing the entry groove or coding hole of the key element, the terms "top" or "bottom" are sometimes used in this specification. This refers to the situation also shown in the figures, where the groove or hole extends into the depth from the upper flat surface.

[0044] With reference to an entry groove, the "length" of the entry groove refers to its extent along its axis (or "x" direction), the "depth" is its extent perpendicular to the flat face of the key (its "z" direction), and the "width" is its extent in a direction perpendicular to the key axis and parallel to the flat face (its "y" direction).

[0045] The subject matter of the invention is explained in more detail below on the basis of exemplary embodiments and the accompanying drawings, in which identical reference signs refer to identical or similar elements. [Brief description of the drawings]

[0046] [Figure 1] FIG. [Diagram 2] FIG. 2 is a perspective view of a locking cylinder with a key, shown in cross section. [Diagram 3] FIG. 2 is a perspective view of a blank key for producing the key according to FIG. 1; [Figure 4] FIG. 4 is a detailed view of FIG. [Diagram 5] 1A-1D are diagrams of the block tumbler and block counter tumbler at four different stages during insertion of the key into the locking cylinder, with the key and locking cylinder depicted in cross section. [Figure 6] 1A-1D are diagrams of the block tumbler and block counter tumbler at four different stages during insertion of the key into the locking cylinder, with the key and locking cylinder depicted in cross section. [Figure 7] 1A-1D are diagrams of the block tumbler and block counter tumbler at four different stages during insertion of the key into the locking cylinder, with the key and locking cylinder depicted in cross section. [Figure 8] 1A-1D are diagrams of the block tumbler and block counter tumbler at four different stages during insertion of the key into the locking cylinder, with the key and locking cylinder depicted in cross section. [Figure 9] FIG. 2 shows a block tumbler and a block counter-tumbler shown in cross section along a plane perpendicular to the key axis, together with details of a key having different configurations of block grooves in the coding area. [Figure 10] FIG. 2 shows a block tumbler and a block counter-tumbler shown in cross section along a plane perpendicular to the key axis, together with details of a key having different configurations of block grooves in the coding area. [Figure 11] FIG. 2 shows a block tumbler and a block counter-tumbler shown in cross section along a plane perpendicular to the key axis, together with details of a key having different configurations of block grooves in the coding area. [Figure 12] Illustrated and cross-sectional views of key elements in three manufacturing stages. [Figure 13] Illustrated and cross-sectional views of key elements in three manufacturing stages. [Figure 14] Illustrated and cross-sectional views of key elements in three manufacturing stages. [Figure 15] A blank key cut along a plane parallel to the key axis with two different embodiments of the entry groove. [Figure 16] A blank key cut along a plane parallel to the key axis with two different embodiments of the entry groove. [Figure 17] FIG. 13 shows a block tumbler with associated key in a further embodiment taken along a plane perpendicular to the key axis. [Figure 18] FIG. 13 shows a block tumbler with associated key in a further embodiment taken along a plane perpendicular to the key axis. [Figure 19] FIG. 2 is a schematic cross-sectional view of an inlet groove in a coding region. [Figure 20] FIG. 20 is a schematic cross-sectional view similar to FIG. 19, but with a relatively deep inlet groove. [Figure 21] FIG. 13 is a view of the tip of a key element with an inlet groove widening toward the rear. [Figure 22] FIG. 22 shows the key tip of the key element according to FIG. 21 with the block tumbler engaging in the inlet groove in the entry area. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] 1 shows an example of a key 1 having a key head 11 and a key shank 12. The key 1 is a flat key in which the key shank is substantially non-square rectangular in cross section perpendicular to the key axis 10, thereby defining two parallel flat faces 21 and two narrow faces 22 that are smaller in area than the flat faces 21. An edge 25 is formed between the flat faces 21 and the narrow faces 22. In the example shown, the narrow faces 22 are not completely flat but are slightly rounded.

[0048] FIG. 1 also illustrates a Cartesian coordinate system used herein, with the x-direction running parallel to the key axis and the z-direction running perpendicular to the flat surface 21 .

[0049] An array of coding holes 31 of various shapes and configurations are provided on the key shank 12 and run parallel to the key axis 10 .

[0050] The key shown is a reversible key, i.e. the key shank is symmetrical with respect to a 180° rotation about the key axis 10 and the coding on the front and rear planar faces 21 is correspondingly identical.

[0051] Towards the key tip 23, the key has an entrance ramp 24 inclined forward at an angle, which allows the locking cylinder to sense the coding hole and have a pin (e.g. tumbler) that projects further into the key channel than the central plane, so that the coding hole can potentially have a depth greater than half the thickness of the key. This has a positive effect on the number of possible permutations.

[0052] FIG. 2 shows the key 1 together with a locking cylinder 101. The locking cylinder 101 has, in a manner known per se, a stator 103 and a rotor 104 attached to it. The rotor 104 is formed with a key channel 105 into which the shaft of the key 1 is inserted. FIG. 2 shows the configuration in which the key is fully inserted. If the key is properly coded, the rotor 104 can rotate relative to the stator 103 about the locking cylinder axis, which is parallel to the key axis. This rotation drives a bolt or other element not shown in FIG. 2.

[0053] The coding of the locking cylinders is realized by the fact that pins serving as tumblers 111 with different tumbler lengths depending on the coding are attached to the rotor 104 and that corresponding spring-loaded counter-tumblers 112 are present in the stator 103 (springs 113). These press the tumblers radially inwards against the stops. By inserting the key, they are lifted against the spring force. If the keys are properly coded, as in the case of FIG. 2, the separation joints (i.e. separation surfaces) between each tumbler 111 and its counter-tumbler 112 coincide with the separation surfaces between the rotor 104 and the stator 103, so that the rotor can rotate away from the position shown in FIG. 2. FIG. 2 also illustrates the principle that firstly the radially inner ends of the tumblers can be different, also in order to detect the shape of the coding holes 31 of the keys, and secondly, that the sum of the lengths of the tumblers and counter-tumblers is the same for all pairs (or at least for groups of pairs), with one exception considered below.

[0054] These principles of locking cylinder design and interaction with the key, which are known per se, are supplemented according to the invention by an entry groove 41 on the key and by a block tumbler 141 and a corresponding block counter-tumbler 142 on the locking cylinder 101, which together can have a greater length than a conventional tumbler / counter-tumbler pair.

[0055] Figure 3 shows a blank key 71 which can be used to manufacture a key according to figure 1. The blank key has an undercut entry groove 41, while only coding holes are drilled into the key and can therefore be used for customization. The key can also have customized features in the area of ​​the entry groove 41 itself, which will be explained below.

[0056] The entry groove extends axially from the key tip 23 along the flat surface 21. In Figure 3 it can first be seen that it is undercut and then that along its axial extent it has a non-constant depth, in that it first passes to a higher level in the entry region 51 and has a first, smaller depth, then passes down to a lower level in the coding region 52 and has a second, greater depth.

[0057] Figures 5-8 show the block tumbler 141 with the block counter tumbler 142 and spring 133 positioned in the rearmost position of the locking cylinder while the key 1 is being inserted, showing four different key positions. Figure 5 shows how the key tip 23 strikes the radially inner end of the block tumbler 141, which then rises due to the entry ramp 24 and is pushed radially outward against the spring force as the key is inserted further.

[0058] Figure 6 shows the situation when the block tumbler is in the entry area. The block tumbler 141 rises until the block counter tumbler 142 almost or completely abuts the sleeve 105 which surrounds the stator 103 of the locking cylinder and supports the spring 103. If the key did not have an entry groove or undercut, it would not be able to reach this position and would be blocked, since 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 normal tumbler 111 and the counter tumbler 112, which can also be seen, for example, in Figure 2.

[0059] In FIG. 7 it can be seen that with further insertion of the key the block tumblers are again deflected slightly radially inwards as the inlet groove drops to a lower level.

[0060] Figure 8 shows the situation when the key 1 is fully inserted and the block tumbler 141 is in the coding position (position of the coding area) relative to the key. As with normal tumblers and counter tumblers, with the appropriate key the separation joint 145 is aligned with the separation surface between the locking cylinder stator 103 and the locking cylinder rotor 104.

[0061] 9 shows an embodiment of a block tumbler 141. Towards its radially inner end it has a neck 152 adjacent to the shaft 151 and a sensing head 153 adjacent thereto that has a larger diameter than the neck 152 and can engage the undercut. The sensing head forms a tapered region 154 towards its radially inner end and has a flat radially inner protrusion 155 which in the embodiment shown forms the tip of the block tumbler.

[0062] At the coding position, different codings depending on the key are also possible, independent of the function of the insertion lock caused by the overall length of the block tumbler 141 and the block counter tumbler 142. Figures 9 and 10 show two corresponding variants.

[0063] In the coding according to Fig. 9, the inlet groove in the coding area and in particular in the coding position is configured with a central recess into which the sensing head 153 engages, so that the block tumbler can abut with its tip against the bottom of the inlet groove and / or with the tapered region 154 against the side of the groove.

[0064] However, as can be seen in figure 10, it can also be provided that the inlet groove of the coding area is milled shallower, so that between the lateral inclined grooves 61 forming the undercut a central web 62 remains, which supports the tip of the sensing head 153. The different heights of this central web up to the situation according to figure 9 (where no central web is visible at all) form different mechanical codings to which the length of the block tumbler 141 is adapted in each case, which is also shown below in figure 19.

[0065] Also shown in FIG. 9 is the pin axis 150. The block tumbler 141 and the block counter-tumbler, for example, are rotationally symmetrical (cylindrically symmetrical) about this axis, as are the normal tumblers and counter-tumblers. Even if the block tumbler 141 does not belong to a key but to a locking cylinder, the alignment of the pin axis 150 is defined and recognizable on the key (and on the blank). The entry groove defines the direction of the pin axis as the direction of a plane perpendicular to the key axis (yz-plane) and as the direction of a plane about which the entry groove is at least partially symmetrical. The direction of the pin axis is generally perpendicular to the bottom of the entry groove in the region of its center and / or exactly in the middle between the sides of the entry groove and / or in the middle between the inclined grooves 61 of the type described and / or in the middle between the undercuts on both sides.

[0066] In the exemplary embodiment of FIG. 9, similar to FIGS. 10 and 11 described below, the pin axis 150 is perpendicular to the planar surface 21.

[0067] Figure 11 illustrates the possibility of adapting the shape of the sensing head 153. The sensing head 153 is flattened at the radially inner end so that the tapered region 154 is shortened, and there is no radially inner protrusion, resulting in a correspondingly enlarged end surface 156. Sensing is therefore performed laterally through the tapered region 154, which is outside the area that can be covered by a scan tool that senses the key shank from a flat surface in order to duplicate the key (see dotted lines in Figure 11).

[0068] If someone were to attempt to replicate the key using conventional milling tools, milling an entry groove across its entire width to accommodate the width of the sensing head 153 as shown by the dashed line in Figure 11, this would fail because the block tumbler would extend too far radially inward until the end surface 156 abutted against the bottom of the overly wide milled groove, which would result in ineffective locking in the configuration shown. It would be impossible to discern from the key to what other depth such a wide groove would have to be milled to successfully open the locking cylinder.

[0069] Thus, the combination of a sensing head configured as shown in FIG. 11 and the undercutting of the entrance groove 41 is an additional security feature and provides copy protection.

[0070] Other options include: Variation in the length of the neck 152. By shortening the neck 152, the block tumbler can already be made to stand on the shoulder 157 between the shaft 151 and the neck 152, in the region of the web 158 above the undercut on the flat surface 21 of the key shank. If a too wide groove is milled by an unauthorized copyist to accommodate the sensing head without providing an undercut, such a standing up does not occur and the block tumbler will also move too far radially inwards, resulting in ineffective locking. Combinations are also possible. In general, there are numerous possibilities where the entry groove or its surroundings can be detected, and it is not clear from the key itself where the block tumbler would effectively do this. Therefore, a key cannot be easily replicated by replicating only its individual features.

[0071] Figures 12 to 14 show stages in the process of making a key, in which cross sections through planes II, II-II and III-III are shown on the right hand side, which are shown in plan view on the left hand side of the figures.

[0072] 12, a preparation groove 91 is first provided in the key moulding body 81, which runs axially along the flat surface of the key tip in the area where the entry groove is to be formed. 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 production of the undercut entry groove.

[0073] Figure 13 shows the produced blank 71 after the entry groove has been produced. In addition to and proceeding from the preparatory groove, an inclined groove 61 is produced by milling with a milling tool with an inclined axis of rotation towards the flat surface, leaving a central web 62 between them. It can also be clearly seen in Figure 13 that the entry groove 41 thus produced runs downward towards the rear towards the coding area, i.e. is deeper, both in the region of the central web and, as is particularly noticeable in the embodiment of Figure 13, in the region of the inclined groove 61.

[0074] The blank is finished in the state shown in Figure 13. In this state it can be sold as a product, for example to a specialist shop that is authorized to customize it.

[0075] The finished customized key can be seen in detail in Fig. 14. On the one hand, during the customization stage, coding holes 31 are drilled, only a few of which are shown in Fig. 14, which can have different shapes as well as different depths. On the other hand, the entry grooves 41 are also modified depending on the customization. In the example of Fig. 14, this is done by partially removing the central web 62 in the coding area 41 to the desired coding depth (see for example cross section III in Fig. 14) as well as by optional post-machining in the entry area (cross section I in Fig. 14).

[0076] 14 also shows the optional feature of a groove extension 94 of the entry groove that is not undercut, which indicates further coding. Optionally, a tumbler / counter-tumbler pair arranged in the same row next to the blocking tumbler (or in the case of a reversible key, a tumbler / counter-tumbler pair in the corresponding position of the locking cylinder rotated 180°) can also sense the groove extension 94 and extend to have a corresponding blocking effect if necessary. In the example shown, one of the coding holes 31 is located in the groove extension.

[0077] Another optional feature seen in FIG. 14 is another entrance groove 95 leading to the first coding location.

[0078] This entry groove 41 can not only be coded by customization (by machining the central web 62), but also by different depths of the inclined grooves 61, as shown in figures 15 and 16. These figures show a blank 71 with a shallower entry groove 41 (figure 15) and with a deeper entry groove 41 (figure 16), respectively. In this way, for example at the "blank" level, a distinction can be made between different incompatible locking systems. For example, by choosing the appropriate overall length of the block tumbler and the block counter-tumbler, the locking cylinder can be configured in such a way that a key with a flatter entry groove cannot be inserted at all. On the other hand, by using the interaction of the sensing heads and the undercuts, different locking cylinders can also be configured in such a way that, for example, a very flat coding (short block tumbler) in the area of ​​the entry groove will never open this locking cylinder if the key has a deeper entry groove.

[0079] Based on the embodiment of FIG. 17, it is first shown that the pin axis 150 does not necessarily have to be perpendicular to the flat surface 21 (as in FIG. 18 below). Rather, as known per se, it can be angled with respect to the normal to the flat surface in the yz plane, i.e. with respect to a plane perpendicular to the key and cylinder axes. This applies optionally to both the block tumbler 141 and to the normal tumbler pins in the corresponding tumbler row. The undercut of the entry groove also applies to these embodiments with respect to the pin axis 150. Also in these embodiments, the entry groove can be symmetrical with respect to a plane passing through the pin axis 150 and parallel to the key axis, i.e. perpendicular to the drawing plane in FIG. 17.

[0080] The option of the pin axis being at an angle other than 0° with respect to the normal to the flat surface 21 applies to features of all embodiments and concepts described herein, independent of the particular features of the embodiments of Figures 17 and 18.

[0081] FIG. 17 also shows the possibility of using a conventional tumbler pin without an extended sensing head as the block tumbler pin 141. In this case, the pin tip with the radially inner projection 155 is directly adjacent to the neck 152. With such a block tumbler pin 141, the undercuts are not detected and it will also work with keys with non-undercut entry grooves if their width is adjusted accordingly. However, in a system with multiple locking cylinders, it may be an option to use both cylinders with an extended sensing head on the block tumbler and cylinders without this sensing head.

[0082] 17 also illustrates the possibility of having a shoulder 157 of the block tumbler resting on the key surface, i.e. on the flat surface 21. In a corresponding embodiment, only the presence of an entry groove, e.g. in the coding area, is detected and not its depth.

[0083] The latter (detecting only the key surface in a lock cylinder configuration) is also an option for an embodiment with an extended sensing head 153, which is shown in FIG. 18. In this embodiment, in addition to the presence of an entry groove, the undercut is also detected. Thereby, the width of the shaft 151 in the region of the shoulder 157 can be similar to the width of the sensing head. Depending on the shape and dimensions of the sensing head, a key with an entry groove of a width large enough to accommodate the sensing head will therefore not work, because in this case the block tumbler cannot stand on the shoulder 157 on a flat surface, but will go too far radially inwards. The possibility of detecting the key surface is therefore also a potential security feature in combination with the undercut.

[0084] Also, the block tumbler 141 of Figures 17 and 18 differs from the block tumblers of the embodiments described above in the shape of the shaft 151, particularly due to the step in the shaft, but this does not affect the other features described herein.

[0085] In Fig. 19 a schematic cross section is drawn through an inlet groove 41 in the coding area. The thick line indicates the inlet groove with a specific first coding (C1), which corresponds to the longest block tumbler. In the example shown, the central plane 160 of the inlet groove, in which the pin axis of the block tumbler lies, is inclined with respect to the normal to the flat surface 21.

[0086] A feature of the entry groove of the key according to the invention, and also of the blank key, is an undercut portion 162 which originates from a flat surface and enters into the depth of the entry groove, tilting away from the central plane, resulting in an undercut. The undercut portion is tilted at an acute angle α with respect to the central plane 160, in particular the angle α can be between 10° and 45°, for example between 15° and 30°.

[0087] Towards the flat surface, the undercut portion can be adjacent to an outer vertical portion 161, which can also be formed on only one side, on the left side in FIG. 19, in the case of an inlet groove inclined relative to the normal to the flat surface as in the example shown.

[0088] In the direction away from the flat surface 21, the undercut portion 162 terminates with an outer bottom portion 163 that is inclined towards the central plane 160, in particular at a second acute angle β. In a number of exemplary embodiments, the second acute angle β is greater than the first acute angle α. In particular, the outer bottom portion 163 can be formed at a right angle to the undercut portion 162. In this case, β=90°-α. Such an outer bottom portion can be easily produced at an angle α to the central plane 160 using a milling tool, in which an inclined groove is milled, as described above with reference to FIG. 13.

[0089] Depending on the coding, an inner vertical portion 164 and an inwardly tapered portion 165 may follow the outer bottom portion.

[0090] The dashed lines show alternative cross-sectional contours resulting from the second coding (C2) and the fourth coding (C4); a third coding between the second and fourth codings is not shown for clarity. From these dashed lines it can be seen that the inner vertical portion 164 does not always result, but rather it is also possible for a reverse gradient to result from the inwardly tapered portion 165.

[0091] Common to all codings is an inner bottom portion 166 whose location in the embodiment where the coding is sensed by the tip of the block tumbler is determined. A central plane 160 passes through the inner bottom portion 166 and generally defines its central vertical plane.

[0092] In FIG. 19, reference numeral 170 designates undercuts bounded by respective dotted lines.

[0093] It can also be seen in Figure 19 that the inlet groove is symmetrical about the central plane 160, although the sidewalls do not rise the same distance on both sides due to the tilted position of the central plane (160); in other embodiments, for example in Figures 17 and 18, a shallow recess next to the inlet groove may also affect the extent to which the sidewalls extend. Where an inlet groove is symmetrical about a central plane, in this specification this may mean that the symmetry exists only from a certain depth measured along the central plane.

[0094] FIG. 20 shows a view of a section through the inlet groove 41 in the coding area, similar to FIG. 19. The inlet groove 41 of the embodiment of FIG. 20 differs from FIG. 19 in that the undercut is deeper, i.e. during production, the transverse inclined grooves were milled deeper into the blank key. This results in a qualitatively slightly different course of the inlet groove side walls, since even in the embodiment with the deepest first coding, there is no inner vertical part. Instead, next to the outer bottom part 163, towards the central plane, there may be a small web 169, which occurs due to the manufacturing process between the milled part forming the inclined groove and the inner bottom part 166. Furthermore, in the embodiment shown, the central plane 160 of the inlet groove is inclined relative to the normal to the flat surface, while the outer vertical parts 161 are formed on both sides.

[0095] 21 and 22 illustrate, with a key 1 shown in cross section, the possibility that the inlet groove 41 has a smaller width (first width b1) on the front side of the entry area than in the coding area (second width b2). The width of the inlet groove at a particular axial position, measured at the widest depth of the inlet groove in the cross section at this axial point, i.e. at the depth of the undercut. As a result, the undercut of the inlet groove 41 can already be detected in the entry area, since if there was no undercut, the detection head 153 would prevent insertion, which can be clearly seen in FIG. 22. FIG. 22 illustrates that the detection head virtually completely blocks the undercut in the entry area, since here the inlet groove is not so wide. In the coding area, the larger second width b2 of the inlet groove has a different coding, i.e. the detection head can be arranged at a different depth relative to the part forming the undercut.

Claims

1. 1. A key element comprising: a key head; and a key shank extending along a key axis from said key head to a forward key tip, said key shank having two parallel flat faces and two opposing narrow faces, and an entry groove extending from said key tip parallel to said key axis in one of said flat faces and having a variable depth along its axial extent, said entry groove being undercut, wherein said key element is a reversible key element in that said key shank is symmetrical about a 180° rotation about said key axis.

2. 2. The key element of claim 1, wherein the inlet groove has a first depth in an entry region and a second, greater depth in a coding region away from the key tip.

3. 3. A key element according to claim 2, wherein the undercut formed by the inlet groove extends to a greater depth in the coding region than in the entry region.

4. 3. A key element according to claim 2, wherein the inlet groove has a smaller width in the entry area than in the coding area.

5. 5. A key element according to claim 1, wherein the side wall of the inlet groove has, at least at one location in a cross section perpendicular to the key axis, an undercut portion that slopes away from the flat surface and away from a central plane of the inlet groove at an acute angle to the central plane.

6. 6. A key element according to claim 5, wherein the acute angle of the inlet groove relative to the central plane is between 10° and 45°.

7. 6. A key element as claimed in claim 5, wherein an outer bottom portion (163) adjoins the undercut portion in a direction away from the flat surface, the outer bottom portion inclined at a second acute angle towards the central plane of the inlet groove.

8. The key element of claim 7 , wherein the outer bottom portion is perpendicular to the undercut portion.

9. 6. The key element according to claim 5, wherein at least one side wall of the inlet groove has an outer vertical portion adjacent to the undercut portion toward the flat surface, the outer vertical portion running parallel to the central plane of the inlet groove.

10. 5. A key element according to claim 1, wherein the inlet groove has, in at least one region, an inner bottom portion which is perpendicular to a central plane of the inlet groove and through which the central plane passes.

11. A key element according to claim 1 , wherein the inlet groove is symmetrical about a central plane of the inlet groove from at least a certain depth.

12. A key element according to any one of claims 1 to 4, wherein the undercut lies in a direction perpendicular to the key axis and parallel to a centre plane of the inlet groove.

13. 5. A key element according to claim 1, wherein the inlet groove comprises two inclined grooves extending away from each other in a cross section perpendicular to the key axis in a direction away from the flat surface.

14. 5. A key element according to claim 1, wherein the inlet groove is undercut on both sides of a central plane of the inlet groove and / or the inlet groove is undercut on at least one side in a direction perpendicular to the flat surface.

15. 5. A key element according to claim 1, further comprising an entrance ramp towards the key tip, the entrance ramp having a depth greater than half the thickness of the key shank.

16. 5. A key element according to any one of claims 1 to 4, which is a blank key for producing flat keys by providing customized coding holes.

17. 14. The key element of claim 13, wherein the inlet groove has two angled grooves and a central web between the angled grooves.

18. 5. A key element according to claim 1, which is a flat key and has in its flat face at least two rows of coding holes parallel to the key axis, one of which is arranged in line with the inlet groove.

19. 20. A locking cylinder for a key element as claimed in claim 18, comprising a locking cylinder stator and a locking cylinder rotor, a key channel disposed on the locking cylinder stator and rotatable relative thereto in a release position, and at least one row of tumbler / counter-tumbler pairs slidably mounted in pinholes in the locking cylinder rotor and the locking cylinder stator and pressed inwardly towards the key channel by a spring, characterized by a block tumbler and an associated block counter-tumbler, the block tumbler having a neck radially inwardly towards the key channel and a sensing head adjacent thereto, the sensing head having a larger diameter than the neck and designed to engage within the undercut entry groove.

20. 20. The locking cylinder of claim 19, wherein the sum of the lengths of the block tumbler and the block counter-tumbler is greater than the sum of the lengths of the tumbler / counter-tumbler pair.

21. 20. A locking cylinder as claimed in claim 19, wherein said block tumbler is disposed at an axially rearmost position in said row of said tumbler / counter tumbler pairs.

22. A locking system having at least one key element according to claim 18 and at least one locking cylinder according to claim 21, wherein the block tumbler is arranged so that it first rises when the key element is inserted into the key channel and then the sensing head is guided into the entrance groove.

23. 23. The locking system of claim 22, wherein the entry groove is designed such that when the key element is inserted, the block tumblers first rise into a first radially outer position and then displace radially inward into a second position.

24. 23. The locking system of claim 22, wherein the sensing head is located in a coding region of the entrance groove when the key element is fully inserted into the key channel.

25. 25. The locking system of claim 24, wherein a radially inner tip of the sensing head rests against a bottom of the entrance groove when the sensing head is located in the coding region.

26. 25. The locking system according to claim 24, wherein the lateral radially inwardly tapered region of the sensing head abuts an inwardly tapered portion of the entrance groove forming a lateral side surface when the sensing head is located in the coding region.

27. 25. The locking system according to claim 24, wherein a shoulder of the block tumbler formed radially outward of the neck abuts the flat surface of the key element when the sensing head is located in the coding area.

28. A method for producing a key element according to any one of claims 1 to 4, comprising the steps of: providing a key molding body having a key shank having two parallel flat surfaces and two narrow surfaces between said flat surfaces, and a key head, said key molding body forming a key tip on a forward side; providing a preparation groove extending axially rearward from said key tip along one of said planar surfaces; providing axially extending inclined grooves on either side extending obliquely from a central plane of the preparation groove proceeding from the preparation groove into the depth of the key shank, resulting in an entry groove having an undercut from the preparation groove having two of said inclined grooves; wherein the angled grooves and / or the preparation grooves are provided such that they have a non-constant depth and, after introducing the angled grooves, the inlet groove is provided having a central web between the angled grooves.

29. 29. The method of claim 28, wherein coding holes are provided to create a flat key and the central web between the angled grooves is at least partially removed.

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