Abstract
A key element having a flat key with a key head and a key shank which extends along a key axis from the key head to a front key tip and has two parallel flat sides and two mutually opposing narrow sides. On at least one of the flat sides, an inlet groove extending from the key tip in parallel with the key axis is provided which has a non-constant depth along its axial extent. The inlet groove can have a first depth, in particular in an entry region, and a second, greater depth in a coding region remote from the key tip. The inlet groove is undercut, as a result of which an expanded sensing head of a block tumbler can engage therein.
Claims
1. A key element having a key head and a key shank which extends along a key axis from the key head to a front key tip and has two parallel flat sides and two mutually opposing narrow sides, having an inlet groove extending from the key tip in one of the flat sides in parallel with the key axis which has a non-constant depth along its axial extent, wherein the inlet groove is undercut, wherein the key element is a reversible key element in that the key shank 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 and a second, greater depth in a coding region remote from the key tip.
3. The key element according to claim 2, wherein an undercut formed by the inlet groove extends to a greater depth in the coding region than in the entry region.
4. The key element according to claim 2, wherein the inlet groove has a smaller width in the entry region than in the coding region.
5. The key element according to claim 1, wherein a side wall of the inlet groove has, at at least one position in a section perpendicular to the key axis, an undercut part which is inclined away from the flat side from a central plane of the inlet groove at an acute angle to the central plane, wherein the acute angle to the central plane of the inlet groove is between 10 and 45.
6. The key element according to claim 5, wherein in the direction away from the flat side an outer bottom part adjoins the undercut part, wherein the outer bottom part is inclined at a second acute angle towards the central plane of the inlet groove, wherein the outer bottom part forms a right angle with the undercut part.
7. The key element according to claim 1, which is a key blank for producing a flat key by providing customised coding holes.
8. The key element according to one of claim 7, wherein the inlet groove has the two oblique grooves and a central web between the oblique grooves.
9. The key element according to claim 1, which is a flat key and has on the flat side at least two rows of coding holes parallel to the key axis, one row of which is arranged collinearly with the inlet groove.
10. A locking cylinder for a key element according to claim 9, with a locking cylinder stator and a locking cylinder rotor with a key channel arranged in the locking cylinder stator and rotatable in a release position relative thereto, as well as at least one row of tumbler/counter-tumbler pairs which are slidably mounted in pin holes in the locking cylinder rotor and in the locking cylinder stator and are pressed inwards in the direction of the key channel by a spring, further including a block tumbler and an associated block counter-tumbler, wherein the block tumbler has a neck radially inwards towards the key channel and a sensing head adjoining thereto radially inwards, wherein the sensing head has a larger diameter than the neck and is designed to engage into the undercut inlet groove.
11. The locking cylinder according to claim 10, wherein a sum of the lengths of the block tumbler and the block counter-tumbler is greater than a sum of the lengths of the tumbler/counter-tumbler pairs.
12. The locking cylinder according to claim 10, wherein the block tumbler is arranged at an axially rearmost position in the row of tumbler/counter-tumbler pairs.
13. A locking system, having the at least one key element and at least one locking cylinder according to claim 12, wherein the block tumbler is arranged such that when the key element is inserted into the key channel, the key channel is first raised and then the sensing head is guided in the inlet groove.
14. The locking system according to claim 13, wherein the inlet groove is designed such that the block tumbler 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.
15. The locking system according to claim 13, wherein the sensing head is located in a coding region of the inlet groove when the key element is fully inserted into the key channel.
16. The locking system according to claim 15, wherein a radially inner tip of the sensing head rests against a bottom of the inlet groove when the sensing head is located in the coding region.
17. The locking system according to claim 15, wherein a laterally radially inwardly tapering region of the sensing head abuts against an inwardly tapering part of the inlet groove forming a lateral flank when the sensing head is located in the coding region.
18. The locking system according to claim 15, wherein a shoulder of the block tumbler formed radially outside the neck abuts the flat side of the key element when the sensing head is located in the coding region.
19. A method for producing a key element according to claim 1, the method including the following steps: providing a key moulded body with a key shank with two parallel flat sides and two narrow sides between the flat sides, and with a key head, wherein the key moulded body forms a key tip on the front side, providing a preparation groove which extends axially rearwardly along one of the flat sides from the key tip, and providing, on both sides, an axially extending oblique groove, which extends proceeding from the preparation groove from a central plane of the preparation groove obliquely into the depth of the key shank, resulting in the inlet groove with an undercut from the preparation groove with the two oblique grooves, wherein the oblique grooves and/or the preparation groove are provided such that they have a non-constant depth, and after introducing the oblique grooves, the inlet groove has a central web between the oblique grooves.
20. The method according to claim 19, wherein coding holes are provided to create a flat key and the central web between the oblique grooves is at least partially removed.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The subject matter of the disclosure will be explained in more detail below on the basis of exemplary embodiments and the accompanying drawings. In the drawings, identical reference numerals denote identical or analogous elements. They show:
(2) FIG. 1 a perspective view of a key;
(3) FIG. 2 a perspective view of a locking cylinder with key, represented in section;
(4) FIG. 3 a perspective view of a key blank for producing a key according to FIG. 1;
(5) FIG. 4 a detail of the view from FIG. 3;
(6) FIG. 5-8 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 drawn in section;
(7) FIG. 9-11 the view of the block tumbler and the block counter-tumbler together with a detail of the keyrepresented in section along a plane perpendicular to the key axiswith different configurations of the block groove in the coding region;
(8) FIG. 12-14 a view and sectional representations of a key element during three phases of production;
(9) FIG. 15-16 a key blank cut along a plane parallel to the key axis, with two different embodiments of the inlet groove;
(10) FIG. 17-18 a view of a block tumbler together with the associated key cut along a plane perpendicular to the key axis in further embodiments;
(11) FIG. 19 a schematic cross-sectional representation of an inlet groove in the coding region;
(12) FIG. 20 a schematic cross-sectional representation analogous to FIG. 19 with a comparatively deeper inlet groove;
(13) FIG. 21 a view of a tip of a key element with an inlet groove widening rearwards; and
(14) FIG. 22 a view of the key tip of the key element according to FIG. 21, together with a block tumbler which engages into the inlet groove in the entry region.
DETAILED DESCRIPTION OF THE DRAWINGS
(15) FIG. 1 shows an example of a key 1 with key head 11 and 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 a key axis 10, thereby defining two parallel flat sides 21 and two narrow sides 22 with a smaller area than the flat sides 21. An edge 25 is formed between the flat sides 21 and the narrow sides 22. In the example represented, the narrow sides 22 are not completely flat, but slightly rounded.
(16) FIG. 1 also shows the Cartesian coordinate system used in this text, with the x direction running parallel to the key axis and the z direction perpendicular to the flat sides 21.
(17) On the key shank 12, rows of coding holes 31 of various shapes and configurations are provided, running parallel to the key axis 10.
(18) The key shown is a reversible key, i.e. the key shank 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.
(19) Towards the key tip 23, the key has an inlet ramp 24 which slopes forwards at an angle, which enables the locking cylinder to have pins (e.g. tumblers) which sense the coding holes and which protrude further into the key channel than to the central plane, such 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.
(20) FIG. 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. On the rotor 104 is formed a key channel 105, 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 locking cylinder axis parallel to the key axis. The rotation drives a bolt or other element, which is not shown in FIG. 2.
(21) The coding of the locking cylinder is achieved by the fact that pins serving as tumblers 111 with different tumbler lengths depending on the coding are mounted in the rotor 104, with corresponding spring-loaded counter-tumblers 112 being present in the stator 103 (springs 113). These press the tumblers radially inwards against a stop. By inserting the key they are lifted against the spring force. If the key is coded appropriately, as is the case in FIG. 2, the separating joint (i.e. the separating surface) between each tumbler 111 and its counter-tumbler 112 coincides with a separating surface between rotor 104 and stator 103, which is why the rotor can be rotated away from the position shown in FIG. 2. Also illustrated in FIG. 2 is, firstly, the principle that the radially inner ends of the tumblers can be different in order to also sense 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).
(22) These principles of a locking cylinder design and interaction with a key that are known per se are supplemented according to the disclosure 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.
(23) FIG. 3 shows a key blank 71 as it can be used for the production of a key according to FIG. 1. The undercut inlet groove 41 is present on the key blank, while the coding holes are only drilled on the key and can thus be used for customisation. The key can also have customised features in the region of the inlet groove 41 itself, which will be described below.
(24) The inlet groove extends along the flat side 21 from the key tip 23 in the axial direction. In FIG. 3, it can firstly be seen that it is undercut and secondly that it has a non-constant depth in that along its axial extent it first runs at a higher level in an entry region 51 and has a first, smaller depth, and then runs lowered to a lower level in a coding region 52 and has a second, greater depth.
(25) FIGS. 5-8 show the block tumbler 141 with block counter-tumbler 142 and spring 133 arranged at a rearmost position in the locking cylinder while the key 1 is inserted, with four different key positions being represented. FIG. 5 represents how the key tip 23 hits the radially inner end of the block tumbler 141, whereupon the block tumbler 141 is raised by the inlet ramp 24 and pushed radially outwards against the spring force when the key is inserted further.
(26) FIG. 6 shows the situation at the time when the block tumbler is in the entry region. The block tumbler 141 is raised so far that the block counter-tumbler 142 almost or completely abuts the sleeve 105 which surrounds the locking cylinder stator 103 and on which the spring 103 rests. If the key did not have the inlet groove or the undercut, the key would not be able to reach this position and 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 also be seen in FIG. 2, for example.
(27) In FIG. 7, it can be seen that the block tumbler is again slightly deflected radially inwards by further inserting the key, as the inlet groove is lowered to the lower level.
(28) 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 region) relative to the key. As with the regular tumblers and counter-tumblers, with a suitable key the separating joint 145 will be aligned with the separating surface between the locking cylinder stator 103 and the locking cylinder rotor 104.
(29) FIG. 9 shows an embodiment of the block tumbler 141. Towards the radially inner end, it has a neck 152 adjoining a shaft 151 and a sensing head 153 adjoined thereto which has a larger diameter than the neck 152 and can engage in the undercut. The sensing head forms a tapering region 154 towards the radially inner end and, in the embodiment represented, has a flat radially inner projection 155 which forms the tip of the block tumbler.
(30) At the coding position, independent of the function of the insertion lock, which is caused by the total length of block tumbler 141 and block counter-tumbler 142, various key-dependent codings are also possible. FIG. 9 and FIG. 10 show two corresponding variants.
(31) In the coding according to FIG. 9, the inlet groove in the coding region and in particular at the coding position is configured such that a depression is formed in the middle into which the sensing head 153 engages. The block tumbler can thereby abut at its tip on the bottom of the inlet groove and/or, with the tapering region 154, on a flank of the groove.
(32) However, it can also be provided that the inlet groove in the coding region is milled less deeply, such that a central web 62 remains between the lateral oblique grooves 61 forming the undercut, on which the tip of the sensing head 153 rests, as can be seen in FIG. 10. Different heights of this central web up to the situation according to FIG. 9 (no central web can be seen 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 FIG. 19.
(33) The pin axis 150 is also shown in FIG. 9. The block tumbler 141 and the block counter-tumbler, for example, are rotationally symmetrical (cylindrically symmetrical) with respect to this axis, just like the regular tumblers and counter-tumblers. Even if the block tumbler 141 does not belong to the key but to the locking cylinder, the alignment of the pin axis 150 is defined and recognisable on the key (and on the blank). The inlet groove defines the direction of the pin axis as a direction in the plane perpendicular to the key axis (the y-z 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 centre and/or 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.
(34) In the exemplary embodiment of FIG. 9, as in FIG. 10 and FIG. 11 described below, the pin axis 150 is perpendicular to the flat side 21.
(35) FIG. 11 illustrates the possibility of adapting the shape of the sensing head 153. The sensing head 153 is flattened at the radially inner end such that the tapering region 154 is shortened, the radially inner projection is also absent and an enlarged end surface 156 is accordingly obtained. The sensing is therefore carried out laterally through the tapering region 154, outside the region which can be covered by a scanning tool which senses the key shank from the flat side in order to copy the key (see the dotted line in FIG. 11).
(36) If someone attempts to copy the key using conventional milling tools and in doing so mills the inlet groove over its entire width to accommodate the width of the sensing head 153, as indicated by the dashed line in FIG. 11, then this will result in failure because the block tumbler will extend too far radially inwards until the end surface 156 abuts against the bottom of the overly wide milled groove, which would result in negative locking in the configuration represented. It is not possible to discern from the key to what other depth such a wide groove would have to be milled in order to successfully unbolt the locking cylinder.
(37) The combination of a sensing head configured as shown in FIG. 11 with the undercut of the inlet groove 41 is therefore an additional security feature and represents copy protection.
(38) Other options include: Variations of the length of the neck 152. A shortened neck 152 can cause the block tumbler to already stand with the shoulder 157 between the shaft 151 and the neck 152 in the region of the web 158 above the undercut on the flat side 21 of the key shank. If the groove is milled too wide by the unauthorised copier to accommodate the sensing head without providing an undercut, such standing-up cannot take place and the block tumbler also moves too far radially inwards, which will cause a negative locking. Combinations are also conceivable. Overall, there are a number of possibilities where the inlet groove or its surroundings can be sensed, 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.
(39) FIGS. 12 to 14 show steps in the process of making a key. In the figures, sections through the planes I-I, II-II and III-III are represented on the right, which are shown in the plan views on the left in the figures.
(40) In a step represented in FIG. 12, a key moulded body 81 is first provided with a preparation groove 91 which runs axially along the flat side of the key tip in the region in which the inlet groove is to be formed. The preparation groove 91 can already have a smaller depth in the entry region 51 than in the coding region 52. It serves to prepare and simplify the creation of the undercut inlet groove.
(41) FIG. 13 shows the blank 71 as it was created after the inlet groove was created. By milling with a milling tool whose rotation axis is inclined towards the flat side, in addition to the preparation groove and proceeding from this, the oblique grooves 61 are created, between which a central web 62 remains. It can also be clearly seen in FIG. 13 that the inlet groove 41 thus created runs lowered towards the rear, towards the coding region, i.e. is deeper, both in the region of the central web and, particularly pronounced in the embodiment of FIG. 13, in the region of the oblique grooves 61.
(42) In the state represented in FIG. 13, the blank is finished. In this state, it can, for example, be sold as a product to specialist shops that are authorised to customise it.
(43) The finished, customised key can be seen in detail in FIG. 14. During the customisation step, on the one hand, the coding holes 31 are drilled, of which only a few are shown in FIG. 14 and which, in addition to different depths, can also have different shapes. On the other hand, the inlet groove 41 is also modified depending on the customisation. In the example of FIG. 14, this is done by partially removing the central web 62 in the coding region 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 entry region (section I of FIG. 14).
(44) FIG. 14 also shows the optional feature of a non-undercut groove extension 94 of the inlet groove, which represents a further coding. Optionally, the tumbler/counter-tumbler pair arranged in the same row adjacent to the block tumbler (or, in the case of a reversible key, the tumbler/counter-tumbler pair at the corresponding position of the locking cylinder rotated by 180) can also be extended in order to also sense the groove extension 94 and, if necessary, to have a corresponding blocking effect. In the example represented, one of the coding holes 31 is located in the groove extension.
(45) Another optional feature seen in FIG. 14 is another inlet groove 95 leading to a first coding position.
(46) The inlet groove 41 can be coded not only by customisation (by machining the central web 62), but also by different depths of the oblique grooves 61, which is illustrated in FIGS. 15 and 16. These figures each show a blank 71 with a shallower 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 configured such that a key with the flatter inlet groove cannot be inserted at all by choosing an appropriate total length of block tumbler and block counter-tumbler. On the other hand, a different locking cylinder can also be configured such that there can be no key with the deeper inlet groove that opens this locking cylindere.g. by a very flat coding in the region of the inlet groove (short block tumbler)by using the interaction between the sensing head and the undercut.
(47) Based on the embodiment of FIG. 17, it is firstly illustrated (as in FIG. 18 below) that the pin axis 150 does not necessarily have to be perpendicular to the flat side 21. Rather, as is known per se, it can be at an angle to the normal to the flat side in the y-z plane, i.e. the plane perpendicular to the key and cylinder axis. This optionally applies to both the block tumbler 141 and 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. Also in these embodiments, the inlet groove can be symmetrical with respect to a plane which passes through the pin axis 150 and is parallel to the key axis, i.e. in FIG. 17 perpendicular to the drawing plane.
(48) 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.
(49) FIG. 17 also shows the possibility of using a conventional tumbler pin without the expanded sensing head as the block tumbler pin 141. The pin tip with the radially inner projection 155 then adjoins directly to the neck 152. In such a block tumbler pin 141, the undercut is not sensed and would also work with keys that have a non-undercut inlet groove if their width is adjusted accordingly. However, in a system with a plurality of locking cylinders, it may be an option to use both cylinders with an expanded sensing head on the block tumbler and those without this sensing head.
(50) Also illustrated in FIG. 17 is the possibility of having a shoulder 157 of the block tumbler abutting on the key surface, i.e. on the flat side 21. In corresponding embodiments, it is not the depth of the inlet groovee.g. in the coding regionthat is sensed, but only its presence.
(51) The latter (sensing only of the key surface in lock cylinder configurations) is also an option in embodiments with the expanded sensing head 153, which is represented in FIG. 18. In this embodiment, in addition to the presence of the inlet groove, the undercut is also sensed. The width of the shaft 151 in the region of the shoulder 157 can thereby be similar to the width of the sensing head. Therefore, depending on the shape and dimensions of the sensing head, a key with an inlet groove whose width is large enough to accommodate the sensing 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 inwards. The possibility of sensing the key surface is therefore also a potential security feature in combination with the undercut.
(52) The block tumblers 141 of FIGS. 17 and 18 also differ in the shape of the shaft 151 from that of the embodiments described above, in particular by the steps of the shaft. However, this does not affect the other features described in this text.
(53) In FIG. 19, a schematic cross-section is drawn through the inlet groove 41 in the coding region. 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 central plane 160 of the inlet groovein which the pin axis of the block tumbler liesis inclined to the normal to the flat side 21.
(54) Characteristic of the inlet groove of keys according to the disclosure and also key blanks is an undercut part 162 which, coming from the flat side and into the depth of the inlet groove, is inclined away from the central plane, which results in the undercut. The undercut part is inclined at an acute angle to the central plane 160, with the angle in particular being able to be between 10 and 45, for example between 15 and 30.
(55) Towards the flat side, the undercut part can adjoin an outer vertical part 161, which in the case of inlet grooves inclined to the flat side normal, as in the example shown, can also be formed on only one side, in FIG. 19 on the left side.
(56) In the direction away from the flat side 21, the undercut part 162 is terminated by an outer bottom part 163 which is inclined towards the central plane 160, in particular at a second acute angle . In many exemplary embodiments, the second acute angle is larger than the first acute angle . In particular, the outer bottom part 163 can be formed at a right angle to the undercut part 162. Then =90. Such an outer bottom part can be easily made by using a milling tool at an angle to the central plane 160, and oblique grooves are milled, as explained above with reference to FIG. 13.
(57) Depending on the coding, an inner vertical part 164 and an inwardly-tapering part 165 may follow the outer bottom part.
(58) 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 part 164 does not always result, and that a counter gradient can also result from the inwardly-tapering part 165.
(59) Common to all codings is an inner bottom part 166 whose position determines the coding in embodiments in which the coding is sensed by the tip of the block tumbler. The central plane 160 passes through the inner bottom part 166 and generally forms its central-vertical plane.
(60) In FIG. 19, reference numeral 170 designates the undercut, delimited by the respective dotted line.
(61) In FIG. 19, it can also be seen that the inlet groove is symmetrical with respect to the central plane 160, except for the fact that the side wall is not raised the same distance 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 have an influence on how far the side wall extends. If the inlet groove is symmetrical with respect to the central plane, this can mean in this text that the symmetry only exists from a certain depth, measured along the central plane.
(62) FIG. 20 shows a representation, analogous to FIG. 19, of a cross-section through an inlet groove 41 in the coding region. The inlet groove 41 of the embodiment of FIG. 20 differs from that of FIG. 19 in that 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 part. Instead, small webs 169 may be present next to the outer bottom part 163 towards the central plane, which, due to the manufacturing process, arise between the milled portion forming the oblique grooves and the inner bottom part 166. In addition, in the embodiment represented, an outer vertical part 161 is formed on both sides, although the central plane 160 of the inlet groove is inclined to the flat side normal.
(63) FIGS. 21 and 22 illustrate, using a key 1 represented in sectioned view, the possibility that the inlet groove 41 has a smaller width (first width b.sub.1) at the front side in the entry region than in the coding region (second width b.sub.2). The width of the inlet groove at a specific axial position measured at the depth at which the inlet groove is widest 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 sensed in the entry region, as the sensing head 153 would prevent insertion if the undercut were not present, which can be clearly seen in FIG. 22. FIG. 22 illustrates that the sensing head practically completely fills the undercut in the entry region because the inlet groove is less wide there. In the coding region, the larger second width b.sub.2 of the inlet groove has different codings, i.e. the sensing head can be arranged at different depths relative to the parts which form the undercut.
