Cylinder lock with flat key having a protected profile

Abstract

A cylinder lock comprising: a stator provided with at least one cylindrical cavity having an axis A; a rotor housed in each cylindrical cavity, wherein each rotor comprises a longitudinal recess along the axis A; a flat key configured to be inserted into the longitudinal recess of the rotor and to control the rotation of the rotor within the stator; wherein the flat key comprises two substantially opposite main faces delimited by two longitudinal edges substantially parallel to the axis A, a widened base end, a tip end, and a set of teeth protruding from one of the two longitudinal edges; wherein a notch is formed on one of the two main faces by material removal, wherein the notch is obtained in a position such that when the flat key is inserted into the rotor, the notch at least partially houses a first sphere of a pair of spheres arranged in series and slidable in a channel obtained in the rotor so as as to free the rotation of the rotor within the stator previously blocked by interference by the second sphere of the pair of spheres; wherein the notch does not have a circular profile and has a length along the axis A greater than the diameter of the first sphere.

Description

Cross-Reference to Related Applications

[0001] This patent application claims priority from Italian utility model application No. 202024000005283 filed on December 16, 2024, the entire disclosure of which is incorporated herein by reference.Technical Field of the Innovation

[0002] The technical field of reference for the present innovation is that relating to cylinder locks with flat keys. In said technical context, the present innovation provides a solution to the problem of making the key profile more protected, where "more protected" means making the key impossible to reproduce except by contacting the official retailer / manufacturer. Furthermore, the solution provided by the present innovation will be more efficient and reliable compared to similar flat keys with machined profiles.State of the Art

[0003] As is known, a cylinder lock with a flat key is a lock that comprises: a stator provided with one or two cylindrical cavities along an axis A, the number depending on whether the lock is designed to provide access to the key from only one side or both sides; for each cavity, a cylindrical rotor housed in the corresponding cavity having a longitudinal recess or slot along the axis A. a flat key configured to be inserted into the longitudinal recess of the rotor.

[0004] The key is defined as flat because it is essentially two-dimensional and comprises two essentially opposite main faces separated by a small thickness and joined on opposite sides by two longitudinal edges substantially parallel to the axis. The key has a widened base end for user handling and an opposite tip end, usually triangular. At least one of the two longitudinal edges is provided with a set of teeth, which cooperate with corresponding movable pins when the key is inserted into the rotor. The heights of the teeth define a unique code. To increase security, it is currently common to provide the key with additional elements. Specifically, it is known to machine blind holes or small circular recesses on one side of the key, which, when inserted into the rotor, partially house one of a pair of movable spheres in a channel obtained in the rotor. Before the circular seat reaches the spheres, the insertion of the key causes the spheres to retract into a position so that the outer sphere is arranged in a seat straddling the stator and the rotor, effectively blocking the rotation of the rotor relative to the stator. When the circular seat reaches the spheres, both spheres move toward the circular seat, so that the inner one is at least partially housed therein and the outer one is entirely in the rotor channel, no longer straddling the stator and rotor. In said condition, turning the key frees the rotor to rotate accordingly.

[0005] Said known technique described above has some drawbacks. The first is that the circular seat for the sphere is easily reproducible even without contacting the official distributor / manufacturer, thus compromising security. Another disadvantage lies in the circular-seat / sphere coupling, which is unable to absorb clearance and forms a snap-fit engagement that significantly stresses the affected components.Object and Summary of the Innovation

[0006] According to the present innovation, a cylinder lock with a flat key is proposed, as defined in the attached claims. The present innovation also extends to the key itself.

[0007] The starting point of the present invention is a lock as previously described in the prior art chapter, namely, a lock comprising: a stator provided with one or two cylindrical cavities along an axis A, the number depending on whether the lock is intended to allow access to the key from only one side or both sides; for each cavity, a cylindrical rotor housed in the corresponding cavity with a recess or longitudinal slot along the axis A a flat key configured to be inserted into the longitudinal recess of the rotor.

[0008] The key is essentially two-dimensional and comprises two essentially opposite main faces separated by a small thickness and joined on opposite sides by two longitudinal edges substantially parallel to the axis. Along the axis A, the key has a widened base end for user handling and an opposite tip end, usually triangular. The heights of the teeth define a unique code.

[0009] In said context, the main aspect of the present innovation is to have formed a notch on one of the two main faces of the key by material removal, thus replacing the aforementioned circular seat. The notch is obtained in such a position that when the flat key is fully inserted into the rotor, the notch at least partially houses the first sphere of a pair of spheres arranged in series and slidable in a channel obtained in the rotor. As in the prior art, before the notch reaches the spheres, the thickness of the key forces the spheres to retract to a position so that the outer sphere is arranged in a seat straddling the stator and rotor, effectively blocking the rotation of the rotor relative to the stator. When the circular notch reaches the spheres, both spheres move toward the circular seat so that the inner sphere is at least partially housed therein and the outer sphere is completely in the rotor channel, no longer straddling the stator and rotor.

[0010] In this condition, turning the key frees the rotor to rotate accordingly.

[0011] The notch according to the present innovation does not have a circular profile and, along the axis A, has a length greater than the diameter of the first sphere.

[0012] Preferably, the notch has a rectangular shape with long sides parallel to the direction of the axis A.

[0013] Preferably, along the axis A, the notch has a length substantially equal to twice the diameter of the first sphere.

[0014] Preferably, along the direction joining the two edges, the notch has a length greater than the diameter of the first sphere but less than the length of the notch along the axis A.

[0015] Preferably, the notch can be connected to the edge devoid of a set of teeth, so as to provide an opening at said edge.

[0016] Preferably, along the direction joining the two edges, the notch is not connected to the face, so as to form two opposite retaining steps for the sphere.

[0017] Preferably, along the axis A, the notch has a variable depth. Even more preferably, along the axis A, the notch has a greater depth at the middle and is connected to the surface of the face at the ends thereof. Even more preferably, in cross-section along a plane parallel to the edges, the notch has a continuous circular-profile depth.

[0018] Finally, preferably, the notch can be obtained substantially at the middle of the face along the axis A or at a position along the axis A between the middle of the face and the tip.Brief Description of the Drawings

[0019] For a better understanding of the present innovation, an embodiment thereof is now described, purely by way of nonlimiting example, with reference to the attached drawings, wherein: Figure 1 is a side view of a cylinder lock with a flat key; Figure 2 is an exploded view of the lock of Figure 1, with some elements removed for clarity; Figures 3-9 are views, cross-sections, and enlargements of details of an example of a flat key according to the present invention; Figures 10 and 11 show successive operational steps of the flat key of the previous figures. Preferred Embodiments of the Innovation

[0020] The accompanying figures show an embodiment of a lock according to the present invention.

[0021] Figure 1 is a side view of a cylinder lock with a flat key. Specifically, Figure 1 shows a lock 1 with a stator 2 that defines two cylindrical housings 3 arranged in series along an axis A. The lock comprises a key 6 with a widened circular head 12 with a through hole 20.

[0022] As shown in Figure 2, each housing 3 contains a rotor 4 that comprises an axial slot 5 into which part of the key 6 is inserted until a step 21, located immediately downstream of the head 12, engages with the rotor 4.

[0023] The key 6 comprises two substantially opposite main faces 7, 8 delimited by two longitudinal edges 10, 11 substantially parallel to the axis A, a tip end 9 opposite the head 12, and a set of teeth 13 protruding from the edge 10 (the opposite edge 11 is flat). The faces have axial grooves to guide the key when inserted into the rotor.

[0024] Figures 3-9 are views, cross-sections, and enlargements of details of the flat key 6 according to the present invention in which a notch 14 has been obtained on the face 7 by material removal. As can be seen in this example, the notch 14 does not have a circular profile but rather, along the axis A, has a length D greater than the length d along the orthogonal direction that joins the two edges 10, 11. Also in this example, along the direction d that joins the two edges 10, 11 the notch 14 is not connected to the face 7 and forms two opposite steps 22. As shown, along the axis A, the notch 14 has a variable depth and has a depth with a continuous circular profile having a greater depth in the middle while it is connected to the surface of the face 7 at the ends. In this example the notch 14 is obtained substantially in the middle of the face 7 along the axis A but it could also have been obtained on the face 7 in a position along the axis A between the middle of the face 7 and the tip 9.

[0025] The position of the notch 14 along the axis A ensures that when the flat key is fully inserted into the rotor 4, the notch 14 at least partially houses a first sphere 15 of a pair of spheres 15, 17 that are arranged in series and slidable (pushed toward the inside of the rotor) in a channel 16 obtained in the rotor 4 (see Figure 11). During the insertion of the key 6 into the rotor 14, the two spheres are pushed outward so that the outer sphere 17 straddles the stator and rotor and blocks the mutual rotation of these components (see Figure 10). Only when the notch 14 reaches the sphere 15 (Figure 11), the latter 15 can advance, moving the sphere 17 so as to free the rotation of the rotor 4 within the stator 2 (previously blocked by interference by the second sphere 17 of the pair of spheres).

[0026] The particular geometry of the notch, extending along the main axis A (approximately twice the diameter of the sphere), the connected edges of the notch along the axis A with respect to the face of the key and the steps along the direction orthogonal to the axis A are characteristics that allow the objects of the present invention to be optimally achieved. In fact, thanks to said geometry, the coupling between the sphere and the notch does not occur snap-fit engagement but is guided progressively during the insertion of the key (progressive penetration), and any clearance can be absorbed by the length of the notch.

[0027] Finally, it is clear that modifications and alternatives can be made to the lock and key described and illustrated herein without departing from the scope of protection of the present innovation, as defined in the attached claims.

Claims

1. A cylinder lock (1) comprising: - a stator (2) provided with at least one cylindrical cavity (3) having an axis (A); - a rotor (4) housed in each cylindrical cavity (3), wherein each rotor (4) comprises a longitudinal recess (5) along the axis (A); - a flat key (6) configured to be inserted into the longitudinal recess (5) of the rotor (4) and to control the rotation of the rotor (4) within the stator (2); wherein the flat key (6) comprises two substantially opposite main faces (7, 8) delimited by two longitudinal edges (10, 11) substantially parallel to the axis (A), a widened base end (12), a tip end (9), and a set of teeth (13) protruding from one (11) of the two longitudinal edges (10, 11); wherein a notch (14) is obtained on one (7) of the two main faces (7, 8) by material removal, wherein the notch (14) is obtained in a position such that when the flat key (6) is inserted into the rotor (4) the notch (14) at least partially houses a first sphere (15) of a pair of spheres (15, 17) arranged in series and slidable in a channel (16) obtained in the rotor (4) so as to free the rotation of the rotor (4) within the stator (2) previously blocked by interference by the second sphere (17) of the pair of spheres (15, 17); wherein the notch (14) does not have a circular profile and has, along the axis (A), a length greater than the diameter of the first sphere (15).

2. The lock as claimed in claim 1, wherein the notch (14) has, along the axis (A), a length substantially equal to twice the diameter of the first sphere (15).

3. The lock as claimed in any one of the preceding claims, wherein along the direction joining the two edges (10, 11) the notch (14) has a length greater than the diameter of the first sphere (15) but less than the length of the notch (14) along the axis (A).

4. The lock as claimed in any one of the preceding claims, wherein the notch (14) can be connected to the edge (10) devoid of the set of teeth (13) so as to have an opening at said edge (10).

5. The lock as claimed in any one of the preceding claims, wherein along the direction joining the two edges (10, 11) the notch (14) is not connected to the face (7), thereby forming two opposite retaining steps for the sphere (15).

6. The lock as claimed in any one of the preceding claims, wherein the notch (14) has a variable depth along the axis (A).

7. The lock as claimed in claim 6, wherein the notch (14) has a greater depth in the middle along the axis (A) and is connected to the surface of the face (7) at the ends thereof.

8. The lock as claimed in claim 7, wherein, in section along the axis (A), the notch (14) has a depth with a continuous circular profile.

9. The lock as claimed in any one of the preceding claims, wherein the notch (14) is formed substantially in the middle of the face (7) along the axis (A) or wherein the notch (14) is formed on the face (7) in a position along the axis (A) between the middle of the face (7) and the tip (9).

10. A flat key (6) for a cylinder lock (1) according to any preceding claim.

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