DE102023121673B3 - Flat key with copy protection - Google Patents

Abstract

The invention relates to a flat key (1) with a key bow (2) and a key shaft (3) for a lock-key system, in which a key channel corresponding to a key profile of the key shaft (3) is provided in a locking cylinder (20), wherein the key shaft (3) has a key back (4), a key tip, two key side surfaces (5, 6) and a key breast (7), wherein the key profile has a paracentric shoulder (8) on the key breast side and the paracentric shoulder (8) is formed by an outer surface (8a) and an inner surface (8b), in particular wherein the outer surface (8a) is essentially formed by one of the two key side surfaces (5, 6) and the inner surface (8b) is arranged parallel to the outer surface (8a), wherein the inner surface (8b) has a distance (b) to the center plane (9) of the key shaft (3), in particular flat key (1), in the range of 0.2 mm to 0.3 mm.

Description

The invention relates to a flat key with copy protection based on a paracentric shoulder. Furthermore, the invention also relates to a lock-key system.

Nowadays, conventional flat keys are copied or imitated for a variety of reasons. This is not always done legally. Manufacturers of lock-key systems generally take the approach that a replacement key can be purchased either by ordering it from the manufacturer or through a certified locksmith. Such certified locksmiths generally use original blanks from the manufacturer in conjunction with a security card, which can be used to make a replacement key. These locksmiths also have a license to copy the keys. However, there are a number of universally applicable key profile copying machines on the market, such as the EasyEntrie from Keymax, Bad Saulgau, Germany. With such copying machines, anyone can copy or duplicate conventional flat key profiles.

From the DE 197 07 932 A1 A flat key is known in which the profile ribs have curved cross-sectional contours to avoid sharp edges.

From the EN 10 2005 036 113 A1 A flat key is known in which grooves are cut starting from the flat sides, whereby the angles of the grooves are chosen in such a way that sharp-edged arms are avoided.

From the EN 10 2018 101 438 A1 Flat key profile with different profile grooves is known.

From the CH718958 A1 A flat key with coding holes and a method for its production are known.

From the EN 601 30 230 T2 Various key manufacturing processes are known.

It is therefore the object of the present invention to provide a flat key which has increased copy protection compared to conventional flat keys and cannot be copied by conventional key profile copying machines.

This object is achieved according to the invention by a flat key having the features of claim 1.

According to the invention, a flat key with a key bow and a key shaft is provided for a lock-key system, in which a key channel corresponding to a key profile of the key shaft is provided in a locking cylinder, wherein the key shaft has a key back, a key tip, two key side surfaces and a key breast, wherein the key profile has a paracentric shoulder on the key breast side and the paracentric shoulder is formed by an outer surface and an inner surface, in particular wherein the outer surface is essentially formed by one of the two key side surfaces and the inner surface is arranged parallel to the outer surface.

What is essential in the flat key according to the invention is that the inner surface has a distance from the center plane of the key shaft, in particular the flat key, in the range of 0.2 mm to 0.3 mm.

The term “key breast side” preferably means that the paracentric shoulder is formed starting from the key breast.

The key side surface is preferably understood to be an outer surface of the flat key, which can comprise one or more partial surfaces. For example, a key side surface can have one or more profile features in the form of profile grooves, steps, notches, etc. In this case, several partial surfaces of the key side surface are preferably formed.

Paracentric preferably means an off-center profile feature that preferably extends beyond the center plane of the flat key. However, it is also possible that the off-center profile feature does not extend beyond the center plane, but rather does not extend from a key side surface to the center plane. In this case, too, a paracentric profile feature is assumed. In particular, the paracentric step is a step that extends along the insertion direction when looking at the cross section of the flat key or when looking at the key tip from the front.

As a rule, a key copy is made with a smaller thickness than the original key. This ensures that the key copy can definitely be inserted into the key channel of the locking cylinder.

The paracentric shoulder ensures that the core pins of the locking cylinder, which interact with the paracentric shoulder, are not in the middle as with conventional flat keys, but queried off-center. Preferably, the core pins are queried at a distance from the center plane determined by the paracentric shoulder. The top of the core pins is usually curved or dome-shaped. This means that if the core pin is queried in the center, it would be queried at its highest point. Due to the curved or dome-shaped top, the core pin is no longer queried at the highest point of the core pin in an off-center query.

The paracentric shoulder of the flat key now provides copy protection in that the specified distance of the paracentric shoulder to the center plane is changed in the key copy due to the smaller thickness compared to the original key. This means that when the key copy is inserted into the locking cylinder, the core pins are not interrogated at the specified distance, but at a different distance. This means that the core pins are no longer pressed in far enough due to their curved or dome-shaped top, or are even pressed in too far, depending on whether the key copy is interrogated more centrally or more off-center. In both cases, the underside of the core pins misses the separation plane. It is therefore no longer possible to lock and close the lock with the key copy.

Furthermore, the paracentric heel offers a further advantage in complying with the DIN18252 (“Profile cylinders for door locks – terms, dimensions, requirements, marking”); DIN18252:2018-05 ; Issue date: 2018-05). Since the paracentric shoulder preferably represents the notch area, i.e. the area in which the notches are provided and at the same time one of the DIN18252 required paracentric profile features, only two additional paracentric profile features need to be provided above the notch area instead of three paracentric profile features. This offers the possibility of arranging more variable profile features above the notch area or above the paracentric step.

The distance between the inner surface and the center plane is preferably the specified distance described above. If the flat key is copied, this distance can no longer be maintained when copying the key. For example, the distance of the key copy would always be more than 0.3 mm. In this case, the core pin of the locking cylinder would no longer be checked at the predefined position, which means that the core pin is not pushed in far enough. The underside of the core pin therefore no longer reaches the parting plane of the locking cylinder and it is not possible to lock the lock with a key copy.

In a preferred embodiment, the paracentric shoulder can extend in the direction of key insertion of the flat key. It is preferably provided that the paracentric shoulder extends over the entire length of the key shaft. This ensures that several core pins arranged in the lock cylinder can be interrogated with the paracentric shoulder over the entire length of the key shaft.

It can also be provided that the paracentric shoulder extends from the key face in the direction of the key back, in particular wherein the extension has a height in the range of 2 mm to 5 mm, preferably 3 mm to 4 mm. In particular, when considering the cross section of the flat key, the paracentric shoulder is to be understood as a rectangular profile that has a height and a width. The width preferably extends from the outer surface to the inner surface of the paracentric shoulder.

In particular, it is provided that the paracentric shoulder has two or more notches, in particular where the two or more notches start from the key face and preferably extend over the entire width of the paracentric shoulder. Notches are preferably understood to mean triangular incisions that can be seen when looking vertically at one of the key side surfaces of the flat key. The paracentric shoulder can preferably have 2 to 10 notches, more preferably 3 to 8 notches, particularly preferably 4 to 7 notches.

Preferably, the notches of the parametric shoulder interact with the core pins of the locking cylinder. Each notch preferably interacts with a corresponding core pin. Depending on how deep or high the notches are, different core pin lengths are used to ensure that the undersides of the core pins always reach the parting plane.

In a preferred embodiment, it can be provided that at least one profile groove is provided on one or both key side surfaces, which extends in the key insertion direction of the flat key. In other words, the at least one profile groove runs parallel to the key back and preferably extends over the entire length of the key shaft. For example, 1 to 12, preferably 2 to 10, more preferably 3 to 8, profile grooves can be provided.

Furthermore, it can preferably be provided that the at least one profile groove is paracentric. This preferably means that the profile groove has a profile depth that extends beyond the center plane of the flat key. Preferably, three or four or five paracentric profile grooves are provided. It can also be possible that in combination with the paracentric profile grooves, further profile grooves are provided that are not paracentric.

The invention can also comprise a lock-key system, in particular a lock-key system with a lock cylinder and a flat key according to one of the embodiments described herein. In particular, the lock cylinder has a key channel corresponding to a key profile of the key shaft and core pins for interrogating key notches of the key profile of the flat key.

Furthermore, the invention can also comprise a method for producing a flat key according to one of the embodiments described herein. In particular, it is provided that a key blank is provided and the flat key is produced by means of machining, in particular by milling, the key blank.

Alternatively or additionally, a method for producing a flat key according to one of the embodiments described herein can be provided, wherein a digital 3D model of the flat key is provided and the flat key is produced by 3D printing based on the digital 3D model, in particular by means of selective laser melting (SLM). The digital model of the flat key can be provided by the manufacturer as a file. The digital model of the flat key can also be created by scanning a model or a flat key.

The flat key according to the invention is used in almost all cylinder lock systems for house, apartment or building doors. Due to its design, the flat key offers mechanical copy protection, since a key copy made using conventional key copying machines can no longer lock the lock cylinder. The key copy is therefore unusable. This prevents, among other things, the illegal duplication of flat keys by non-certified key services.

• 1 zeigt eine schematische Darstellung eines Raumbilds eines Flachschlüssels.
• 2 zeigt eine schematische Darstellung einer Seitenansicht eines Flachschlüssels.
• 3 zeigt eine schematische Darstellung eines Querschnitts eines Flachschlüssels.
• 4 zeigt eine schematische Darstellung eines Querschnitts eines Schließzylinders mit eingeschobenen Flachschlüssel.
• 5 zeigt ein Diagramm, bei dem die Kernstiftposition über der Parazentrizität des parazentrischen Absatzes des Flachschlüssels dargestellt ist.

The invention is explained below using several embodiments with the aid of the accompanying drawings. The embodiments shown are therefore not to be understood as limiting.

• 1 shows a schematic representation of a spatial image of a flat key.
• 2 shows a schematic representation of a side view of a flat key.
• 3 shows a schematic representation of a cross section of a flat key.
• 4 shows a schematic representation of a cross-section of a locking cylinder with an inserted flat key.
• 5 shows a diagram showing the core pin position versus the paracentricity of the paracentric shoulder of the flat key.

The figures show different examples of embodiments of the invention. Components that are the same or have the same effect are provided with the same reference symbols. Where the embodiments shown in the figures have similarities, these similarities have not been described multiple times to avoid repetition. The respective differences between the embodiments are described in relation to the figures. It goes without saying that the person skilled in the art can modify individual embodiments or combine individual features of these embodiments with one another within the scope of protection of the claims.

1 shows a schematic representation of a spatial image of a flat key 1. The flat key 1 has a key bow 2 and a key shaft 3. The key shaft 3 is preferably formed in one piece with the key bow 2. It is preferably possible for the key bow 2 to be thicker than the key shaft 3 or vice versa.

The key shaft 3 has a key back 4, a key tip, two key side surfaces 5, 6 and a key breast 7. The key shaft 3 preferably forms a key profile which corresponds to a key channel of a locking cylinder 20.

2 shows a schematic representation of a side view of a flat key 1. The 2 The flat key 1 shown corresponds to the 1 shown flat key 1. Thus, in 2 a vertical view of one of the key side surfaces 5, 6 of the flat key 1. The 2 Flat key shown 1 has a key profile in which a paracentric shoulder 8 is provided on the key face side. The paracentric shoulder 8 is preferably visible when looking at the cross section and can also be formed by several notches 10, as in 2 indicated, be formed.

In 3 is a schematic cross-section of the flat key 1, in particular of the key shaft 3, at the position of 2 shown cutting line. Essentially, the cross section of the flat key 1 or the key shaft 3 is formed by the key back 4, the two key side surfaces 5, 6 and the key face 7. As in 3 As shown, the two key side surfaces 5, 6 are each interrupted by a profile groove 11, 12. The profile grooves 11, 12 preferably extend in the key insertion direction of the flat key 1. This means that the profile grooves 11, 12 run parallel to the key back 4 and preferably extend over the full length of the key shaft 3. The profile grooves 11, 12 preferably represent additional profile features which further increase the copy protection of the flat key 1.

In a preferred embodiment, the at least one profile groove 11, 12 can be paracentric. This means that the profile groove 11, 12 has a profile depth that extends at least beyond the center plane 9 of the flat key 1.

Furthermore, in the 3 The cross-sectional view of the flat key 1 shown shows the paracentric shoulder 8, which is formed by an outer surface 8a and an inner surface 8b. In the embodiment shown, the outer surface 8a is essentially formed by the key side surface 5 and the inner surface 8b is arranged parallel to the outer surface 8a. Alternatively, it can also be provided that the outer surface 8a of the paracentric shoulder 8 is formed by the key side surface 6. In an alternative embodiment, it is also possible that the inner surface 8b and the outer surface 8a are not arranged parallel to one another, but are arranged, for example, at an angular offset.

As mentioned at the beginning, paracentric means an off-center arrangement of a component. As in 3 As shown, the inner surface 8b of the paracentric shoulder 8 is arranged at a distance b from the center plane 9 of the key shank 3. Preferably, the distance b is in a range of 0.2 mm to 0.3 mm.

As in 1 and 2 As shown, the paracentric shoulder 8 preferably extends in the key insertion direction of the flat key 1. It can be provided that the paracentric shoulder 8 extends over the entire length of the key shaft 3.

Furthermore, the paracentric shoulder 8 extends from the key breast 7 in the direction of the key back 4. The extension preferably has a height a in the range of 2 to 5 mm, preferably from 3 mm to 4 mm.

As already mentioned 2 explained, the paracentric shoulder 8 can have two or more notches 10, in particular where the two or more notches 10 start from the key breast 7 and preferably extend over the entire width of the paracentric shoulder 8. Width is to be understood as the extension of the paracentric shoulder 8 from its outer surface 8a to the inner surface 8b. The notches 10 preferably interact with the core pins 23 and are thus intended to ensure that the core pins 23 of the locking cylinder 20 are pressed in as far as the parting plane, so that the locking or locking of the locking cylinder is possible. In the case of a key copy which, as mentioned at the beginning, is thinner than the original key, the core pins 23 are interrogated by means of the notches 10 in a different position than in the original, which is why it is no longer possible to lock or close the locking cylinder.

In 4 is a schematic representation of a cross section of a locking cylinder 20 with inserted flat key 1, as for example in the 1-3 shown. The locking cylinder 20 comprises a cylinder housing 21, in the bore of which a cylinder core 22 is rotatably mounted. A key channel is provided in the cylinder core 22 itself, into which a corresponding flat key 1 can be inserted. Along the center plane 9, one or more pin bores are provided vertically from below in both the cylinder housing 21 and the cylinder core 22, which are arranged along the insertion direction of the flat key 1. In this case, a housing pin 24 is arranged in each of the pin bores in the cylinder housing 21 and a core pin 23 is arranged in each of the pin bores in the cylinder core 22. In this case, a core pin 23 works together with a housing pin 24 and thus forms a pin pair.

Preferably, it can be provided that each housing pin 24 interacts with a spring (not shown) in the cylinder housing 21. The spring ensures that the housing pin 24 is brought into a zero position together with the core pin 23.

If a flat key 1 is now inserted into the keyway, the core pins 23 are displaced or pushed out due to the key profile. pressed downwards. The core cylinder can only be locked or unlocked by rotation with the flat key 1 if all the undersides of the core pins 23 are essentially congruent with the parting plane within the manufacturing tolerances. Conversely, this also means that all the top sides of the housing pins 24 are essentially congruent with the parting plane within the manufacturing tolerances.

As already explained above, the notches 10 of the flat key 1, which are arranged along the paracentric shoulder 8, interact with the core pins 23 of the locking cylinder 20. This is also shown in the cross-sectional view according to 4 illustrated. In cross-section, the paracentric shoulder 8 is in contact with the top of the core pin 23. The top of the core pin 23 is not flat, but curved and/or tapered. The contact between the paracentric shoulder 8 or notches 10 and the top of the core pin 23 preferably always forms a linear and bilateral contact.

As in 4 As shown, the contact system is paracentric, ie off-center. In conventional flat keys 1, the contact system between the notches of the key and the top of the core pin 23 is usually centric, ie the notches touch the core pin at its highest point.

As mentioned at the beginning, key copies are usually made thinner than the original in order to ensure that the key copy can always be inserted into the key channel. With conventional keys, the contact with the core pin 23 is central, the locking mechanism of the cylinder lock can still be reliably activated with a thinner, copied key, since the contact with the core pin 23 is always central even with a thinner key copy. This is due to the fact that the notches of the key copy are always arranged on the central plane 9 of the key, even with a thinner thickness.

However, if a thinner key copy is made from a flat key 1 according to the invention with a paracentric shoulder 8, the distance b of the paracentric shoulder 8 to the center plane 9 of the flat key 1 increases in the key copy compared to the original key due to the reduction in thickness. Due to the increased distance b, the contact system of the key copy with the core pin 23 no longer matches the contact system of the original key with the core pin 23. This means that the contact system is more off-center in the key copy than in the original. The core pin 23 is therefore no longer pressed down far enough and therefore no longer reaches the separation plane. This makes it impossible to close the locking cylinder.

5 shows a diagram in which the core pin position is shown via the paracentricity of the paracentric shoulder 8 of the flat key 1. The paracentricity is preferably given as distance b, as for example in 3 shown. As already mentioned 3 As explained, the distance b is preferably in a range of 0.2 mm to 0.3 mm. Using the diagram according to 5 it is clear that the core pin position increases with larger distances. From distances greater than 0.3 mm, the change in the core pin position increases significantly. Furthermore, with distances greater than 0.3 mm, there is a high risk that the core pin 23 will tilt in the core bore due to the off-center contact point with the paracentric shoulder 8. In this case, the locking function of the locking cylinder begins to jam and may no longer be able to be operated.

List of reference symbols

1

Flat key

2

Key bow

3

Key shaft

4

Key back

5, 6

Key side surfaces

7

Key chest

8

paracentric heel

8a

Exterior surface

8b

Inner surface

9

Middle level

10

score

11, 12

Profile groove

20

Lock cylinder

21

Cylinder housing

22

Cylinder core

23

Core pin

24

Housing pin

a

Height

b

Distance

Claims (7)

Flat key (1) with a key blade (2) and a key shaft (3) for a lock Key system in which a key channel corresponding to a key profile of the key shaft (3) is provided in a locking cylinder (20), the key shaft (3) having a key back (4), a key tip, two key side surfaces (5, 6) and a key breast (7), the key profile having a paracentric shoulder (8) on the key breast side and the paracentric shoulder (8) being formed by an outer surface (8a) and an inner surface (8b), in particular the outer surface (8a) being formed essentially by one of the two key side surfaces (5, 6) and the inner surface (8b) being arranged parallel to the outer surface (8a), characterized in that the inner surface (8b) has a distance (b) from the center plane (9) of the key shaft (3), in particular the flat key (1), in the range from 0.2 mm to 0.3 mm. Flat key (1) after Claim 1 , characterized in that the paracentric shoulder (8) extends in the key insertion direction of the flat key (1). Flat key (1) according to one of the preceding claims, characterized in that the paracentric shoulder (8) extends from the key face (7) in the direction of the key back (4), in particular wherein the extension has a height (a) in the range from 2 mm to 5 mm, preferably from 3 mm to 4 mm. Flat key (1) according to one of the preceding claims, characterized in that the paracentric shoulder (8) has two or more notches (10), in particular wherein the two or more notches (10) start from the key face (7) and preferably extend over the entire width of the paracentric shoulder (8). Flat key (1) according to one of the preceding claims, characterized in that at least one profile groove (11, 12) is provided on one or both key side surfaces (5, 6), which extends in the key insertion direction of the flat key (1). Flat key (1) after Claim 5 , characterized in that the at least one profile groove (11, 12) is paracentric. Lock-key system comprising a locking cylinder (20) and a flat key (1) according to one of the preceding claims, wherein the locking cylinder (20) has a key channel corresponding to a key profile of the key shaft (3) and core pins (23) for querying key notches of the key profile of the flat key (1).

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