PROGRAMMABLE LOCK CYLINDER

Description

[0001] The invention relates to a locking cylinder, in particular a programmable locking cylinder, and to a method for programming a locking cylinder.

[0002] Lock cylinders consist of a stator (sometimes called the "cylinder housing") that is fixed to a lock and cannot rotate, and a rotor (sometimes called the "cylinder core") that rotates around the cylinder's axis when a matching key is inserted. The rotation of the rotor moves drive mechanisms that actuate a bolt or other components related to the desired function of the lock cylinder.

[0003] Many mechanical lock cylinders, whether for reversible keys or pin tumbler keys, have long been based on the same operating principle. The rotor is a cylinder inserted into the stator, with several bores extending through both the rotor and the stator. Each bore contains a tumbler, a counter-tumbler, and a coil spring. The tumbler and counter-tumbler are movable along the bore axis and are restored by the coil spring. When a key matching the lock cylinder is inserted, the tumblers position themselves so that the separation surface (i.e., the shear plane) formed between the tumbler and counter-tumbler coincides with a shear plane (i.e., the shear plane) between the rotor and stator. Thus, the tumbler is completely within the rotor, and the counter-tumbler is completely within the stator.This allows the rotor to rotate within the stator and can thus enable the unlocking of a locking system.

[0004] Lock cylinders are typically manufactured to individual specifications, with each pin having a length precisely matched to its corresponding key. These lengths correspond to the coding engraved in the key, which is manifested in recesses of varying depths at defined positions on the key (and read by the respective pin). This necessitates significant logistical effort to transport the manufactured lock cylinders to their point of use or to retailers, especially when the cylinder is intended to replace another or become part of a larger locking system. Furthermore, the production of customized lock cylinders usually requires considerable manual labor to assemble the numerous individual components.

[0005] Therefore, various methods have been proposed for subsequently programming, or individualizing, a lock cylinder after assembly. In the case of programmable lock cylinders, a generic, i.e., not yet individualizable, but still programmable lock cylinder can be manufactured, enabling more efficient and automated production. Alternatively, generic lock cylinders can be supplied that are programmed later, for example, at the point of use or at a dealer.

[0006] For example, WO 2010 / 103032 A1 proposes providing tumblers whose length can be adjusted by rotating a section of the tumbler with an internal thread relative to a section with a matching external thread. This requires the creation of very small threads, particularly in reversible key cylinders. Furthermore, it must be ensured that the length of each tumbler is set with sufficient accuracy during programming and that this setting remains sufficiently accurate even after years of use of the cylinder.

[0007] US 2005 / 0217331 discloses a programmable lock cylinder in which the shear surface between the lock cylinder rotor and the lock cylinder stator can be adjusted for each tumbler-counter-tumbler pair by allowing so-called shear sleeves to be mounted in adjustable positions. US 2 232 017 discloses a lock cylinder with two-part tumblers, which can be programmed in the presence of a key before the lock cylinder is assembled.

[0008] Other programmable locking cylinders are known, for example, from EP 2 152 986, WO 2007 / 050511 A2 and US 2003 / 0084692 A1.

[0009] US Patent 3,190,093 discloses a locking system for pin tumbler keys in which the cylinder is initially programmed for a temporary key. The cylinder features a special pin tumbler-counter-tumbler pair at one position. The pin tumbler has a sleeve and an additional element, such as a ball, that can be inserted into the sleeve against friction. This additional element is rounded at the interface with the counter-tumbler. If a secondary key with a shallower notch is used at the location of the special pin tumbler-counter-tumbler pair, the cylinder will lock due to the excessive length of the pin tumbler. However, by turning the cylinder with sufficient force, the user can push the additional element further into the sleeve against friction, thus shortening the pin tumbler to fit the secondary key. The temporary key will then no longer fit.

[0010] This reprogramming system has the disadvantage that reprogramming is very limited and only possible in one direction (from a key with a deeper notch to a key with a shallower notch). Therefore, the system is also unsuitable for the concept of first manufacturing a generic, unprogrammed cylinder and only programming it later, for example, on-site. Furthermore, it is very delicate to ensure that the force required to push the additional element into the sleeve (exerted by a shearing motion) does not become too great, while simultaneously risking loosening the connection between the sleeve and the additional element.

[0011] US 2,194,469 relates to a locking system with a reprogrammable cylinder lock in which an upper and a lower part of each tumbler can be fixed relative to each other in different axial positions, the fixing being accomplished with the aid of a rake. US 2,232,137 also teaches a reprogrammable cylinder lock in which the reprogramming is accomplished with the aid of a tool.

[0012] The object of the invention is to create an alternative programmable locking cylinder that overcomes the disadvantages of the prior art. In particular, programming should be simple, fast, and / or secure. Furthermore, a corresponding method for programming a locking cylinder should be provided.

[0013] A further object of the invention is to provide a programmable locking cylinder that is mechanically robust, in particular so that the programming remains accurate even after years of use and / or other mechanical stress. A further object of the invention is to enable particularly simple programming of a locking cylinder. A yet another object of the invention is to enable particularly fast and / or particularly precise programming of a locking cylinder. The programmable locking cylinder and / or the tools used for programming should preferably be relatively easy to manufacture and meet high security requirements.

[0014] At least one of these tasks is solved at least partially by devices and methods according to the patent claims.

[0015] A locking cylinder of the type described here is a mechanical locking cylinder (which does not preclude the additional presence of electronic / electromechanical security features) and has a stator and a rotor rotatable within the stator, with a keyhole into which a key can be inserted. It further has a plurality of tumbler-counter-tumbler pairs mounted in bores in the rotor and stator, respectively, the corresponding bores of the rotor and stator being aligned when the rotor is in a starting position relative to the stator, allowing for the insertion and removal of a key.

[0016] According to the invention, it is proposed to provide a locking device comprising two parts whose relative position is adjustable and fixable by connecting the two parts in a press fit.

[0017] Furthermore, a locking cylinder is designed in such a way that it can be programmed by a tool which exerts a thrust force on the counter-lock or directly on the locking pin in order to push the two parts of the locking pin (further) into each other, while a key with the desired coding is inserted into the cylinder and forms an internal stop for the respective locking pin which depends on the coding.

[0018] The programming of the mechanical locking cylinder is achieved through an interaction between a tool that pushes the locking pin (directly or via the counter-locking pin) inwards to a certain position on the one hand, and the pre-made key with the correct coding on the other.

[0019] For this purpose, the lock cylinder has an access point for the tool, through which the tool can act on the counter-latch or tumbler, for example, in the fully assembled state of the lock cylinder (in which a spring presses the respective counter-latch inwards). Such access consists, for example, of an access opening for each tumbler-counter-latch pair with a programmable (length-adjustable) tumbler.

[0020] In contrast to the prior art, the locking cylinder has a helical spring associated with the locking pin and the counter-locking pin, as well as a housing enclosing the stator, wherein the helical spring abuts an inner surface of the housing with one end facing away from the key opening, and that the housing has an access opening through which the pin of the tool can be passed in order to displace the second part relative to the first part, wherein, when the first and second parts are pushed together, the pin of the tool extends through at least a part of the helical spring.

[0021] For example, a generic (programmable) lock cylinder can be manufactured in which the tumblers, counter-tumblers, and springs are already mounted, and the stator is encased in a sleeve or other housing. The two parts of the tumblers are connected to each other (especially in an interference fit) in such a way that the tumblers are all at least as long as is required for any key for which the lock cylinder is to be programmable.

[0022] When a key is inserted for which the lock cylinder is to be programmed, the tumblers only need to be shortened (by sliding the two parts together) until the dividing line between the tumblers and the counter-tumblers for all tumbler-counter-tumbler pairs coincides with the dividing line between the rotor and stator. The rotor can then rotate within the stator; the tumblers have precisely the required length. To ensure that the correct tumbler length is achieved after sliding the two parts together, a simple tool with a pin (or rod) can be used for programming. This tool can be inserted, for example, along the bore axis for the tumbler-counter-tumbler pair into the stator (and possibly...).(also through a sleeve or other housing) in order to then exert a thrust force on the counter-hold or directly on the locking mechanism, by which the two parts of the locking mechanism are pushed (further) into each other.

[0023] The tool can have a mechanical stop that prevents the pin from being inserted further into the cylinder precisely when the desired position is reached (the parting line between the locking pin and the counter-locking pin coincides with the parting line between the rotor and the stator). Depending on the complexity of the cylinder, a simple tool (e.g., with multiple pins of equal length) may suffice for all locking pin-counter-locking pairs, allowing all locking pin-counter-locking pairs of the cylinder to be programmed simultaneously or sequentially, e.g., row by row. Alternatively, different tools may be required for different locking pin-counter-locking pairs.

[0024] This makes it possible to create a programmable locking cylinder, which can be programmed in a particularly simple way.

[0025] Of course, it is not excluded that the locking cylinder may have further locking cylinder pairs in addition to the aforementioned locking cylinder pairs with (at least) two-part locking cylinders, for example with ordinary one-part locking cylinders.

[0026] In one embodiment, the effective closing length of each of the locking elements can be reduced by sliding the respective first and second parts together.

[0027] The effective locking length is the length that the locking device measures along a bore axis that defines the bore in the rotor in which the locking device is mounted (in this text the term "bore" is used regardless of how the corresponding structures (holes / cavities / openings) are manufactured, i.e. it is not limited to manufacture by drilling).

[0028] The counter-lock, which is used in combination with the length-adjustable locking mechanism (due to the adjustable relative position of the first and second parts), can in some embodiments be a conventional, one-piece counter-lock. This is particularly sufficient for locking systems with only moderate security requirements.

[0029] However, in locking systems with high security requirements, it is required that the sum of the locking effective length of the locking pin and counter-lock is constant, so that the locking pin length cannot be read using measuring instruments.

[0030] To create this possibility, at least one of the locking devices has a first and a second part that can be brought into different positions relative to each other and fixed in these positions, and at least the associated counter-lock has a third and a fourth part that can be brought into different positions relative to each other and fixed in these positions, wherein a closing effective total length of the locking device along an axis depends on the relative position of the first and the second part, and a closing effective total length of the counter-lock along an axis depends on the relative position of the third and the fourth part.

[0031] According to these embodiments, both the locking mechanism and the counter-locking mechanism are adjustable in their effective closing length.

[0032] In particular, the first, second, third, and fourth parts can be shaped and arranged relative to each other in such a way that a movement of the fourth part relative to the third part by a path length L causes a movement of the second part relative to the first part by the same path length L. If such a displacement of the second part relative to the first part causes the locking mechanism to shorten by L, it can simultaneously be ensured that the length of the opposing locking mechanism increases by L – thus, the sum of the lengths remains constant.

[0033] For this purpose, the second part can be arranged axially within the fourth part with respect to the bore axis and be aligned with it. Furthermore, an outer portion of the first part can be aligned with an inner portion of the third part.

[0034] This occurs, for example, when the first part forms the inner, key-side end of the locking mechanism (which also scans the key's coding), the third part forms an outer end of the counter-lock, and a distance between the first and third parts is kept constant; when the fourth part is moved relative to the third part (e.g., pushed inwards) and thereby moves the second part relative to the first; or when, as explained below, the second part is moved independently of the fourth part.

[0035] For this purpose, a separation arrangement can be present between the first and third parts, which is in physical contact with both parts and defines a plurality of possible separation interfaces between the first and third parts – namely, at least where the separation arrangement is in contact with the first part and where it is in contact with the third part, and, for example, also within the separation arrangement itself. In the latter case, the separation arrangement may, for instance, have several separation elements that are not connected to each other or are only loosely connected (via a predetermined separation point).

[0036] In embodiments with the separation arrangement, on the one hand the second and fourth parts can be aligned with each other and jointly displaceable in the axial direction relative to the first and third parts - at least inwards - and on the other hand an outer part of the first part, the separation arrangement and an inner part of the third part can be aligned with each other.

[0037] In particular, the second and fourth parts can be arranged radially inside the inner portion of the third part (preferably the entire third part), the separation arrangement, and the outer portion of the first part, which surround the second and fourth parts in a sleeve-like manner. In such embodiments, the separation arrangement can, for example, comprise one or, preferably, several rings, which in the latter case are loosely stacked on top of each other or connected to one another by a detachable connection (in particular, a predetermined separation point).

[0038] The actual separation joint between the locking and counter-locking joints is defined by the - movable, i.e., programmable - separation joint between the second and fourth parts.

[0039] In some embodiments, however, programming is possible that allows the second part to be positioned at a distance from the fourth part, enabling multiple different codes to be assigned to the tumbler-counter-tumbler pair (multiple code levels). This is suitable for more complex locking systems with multiple keys opening a single lock (so-called Master Key Systems, MKS). To move the second part without moving the fourth part, a programming tool can act directly on the second part. For this purpose, the fourth part can have a through-hole through which the programming tool can act on the second part even when the cylinder with the counter-tumbler is already assembled.

[0040] A programming tool of the type described above can, in addition to the mandrels, also have at least one programming pin, which is guided, for example, within the tool and, during programming, protrudes beyond the stop to such an extent that the second part is displaced relative to the first part by the desired amount. Such a programming pin can, for example, be guided coaxially within the bore of the tool and axially through an internal opening in the respective mandrel. For programming, the programming pin can be moved to different positions relative to the stop surface of the tool, with this position being selected, for example, depending on the known coding of the key at the position of the corresponding locking-counterlock pair.

[0041] As an alternative to programming in the manner described above with direct action on the second part, an MKS system can also be achieved by not equipping certain bores with locking-counterlock pairs or by designing some locking-counterlock pairs conventionally and providing them with one or more coding discs, so-called "split pins".

[0042] In one embodiment, the first part forms a key-side end of the respective tumbler for scanning a key inserted into the lock cylinder, and the second part forms a counter-tumbler-side end of the respective tumbler for interaction with the respective associated counter-tumbler.

[0043] In one embodiment, a stop is formed by the respective first part to limit the movement of the respective locking pin into the keyway. This can make it more difficult or even impossible to optically read the coding. For limiting the movement, the stop interacts with a stop in the rotor bore for the locking pin.

[0044] In particular, it may be provided that the first parts each have a section (for example, an annular section in cross-section) in which they fill the cross-section of a bore in the rotor, in which the respective locking device is movably mounted. The same may additionally or alternatively apply (if present) to the third part and / or the separation arrangement. Naturally, sufficient clearance must remain to ensure the locking device's mobility within the opening in the rotor.

[0045] It is also possible (additionally or alternatively) that the second parts each have a section in which they completely fill the cross-section of a bore in the rotor, in which the respective locking element is movably mounted. This can lead to increased mechanical stability and load-bearing capacity of the locking cylinder and, consequently, to increased security of the locking cylinder. In this context, the second part can, for example, be T-shaped or mushroom-shaped. This possibility is eliminated in embodiments with the separation arrangement if, as preferably, it is located radially on the outside.

[0046] In one embodiment, the second part forms a punch (also referred to as a shaft) which is inserted into an opening in the associated first part that is press-fitted to it. In particular, such a punch can be cylindrical and the opening in the associated first part can be hollow cylindrical.

[0047] The first part can, for example, be sleeve-shaped at least on the outside.

[0048] The first and / or second part can, for example, be rotationally symmetrical, in particular a turned part. The same optionally applies to the third and / or fourth part and / or the separation arrangement.

[0049] The bores in the rotor or stator, for example, run radially with respect to the rotor's axis of rotation, which particularly favors the use of rotationally symmetrical parts. However, bore axes that are skew with respect to the axis of rotation are also conceivable – depending on the arrangement of the coding on the key.

[0050] In one embodiment, the first part forms an outer guide and the second part an inner guide. However, it is also possible to reverse this, so that the first part forms an inner guide and the second part an outer guide. Similarly, the third part and the separation arrangement may form an outer guide and the second and fourth parts an inner guide – or possibly vice versa.

[0051] The corresponding inner-outer guide pair can, on the one hand, ensure movement of both parts along the same axis during programming and, on the other hand, if necessary (in a sufficiently long version), create a strong press fit and thus high mechanical stability of the connection between the two parts. As already mentioned, the first and second parts, in particular, are connected to each other in a press fit, allowing them to slide relative to one another. The same can additionally or alternatively be the case for the third and fourth parts in certain embodiments.

[0052] An interference fit is sometimes also referred to as an interference fit. With an interference fit, the two parts are so tightly connected that they maintain their relative position even after years of use and other typical mechanical stresses. Furthermore, the length of the locking element can be adjusted during programming by applying mechanical forces. These forces are sufficient to allow the two parts in the interference fit to be moved relative to each other, thus adjusting the length of the locking element and consequently programming it.

[0053] In one embodiment, the first or third and / or the second or fourth parts and / or optionally the elements of the separation arrangement are made of one of the materials. Bronze; brass; steel, in particular free-cutting steel or spring steel or silver steel or sintered steel; or also ceramic; an artificial material (e.g. an artificial stone, or also a polymer-based plastic, with or without filler); another metal; in particular a sintered metal or another sintered material.

[0054] In particular, the first, second, and, where applicable, third, fourth parts and / or parts of the separation arrangement can consist of the same or entirely or partially different materials. Any combinations and permutations are possible.

[0055] In one embodiment, it is particularly provided that the first / third part is made of bronze and the second / fourth part of bronze; or the first / third part of bronze and the second / fourth part of brass; or the first / third part of silver steel and the second / fourth part of brass; or the first / third part of bronze and the second / fourth part of spring steel; is made.

[0056] In the event that the second / fourth part forms the radially outer part in the press fit, the specified material pairings are exactly reversed.

[0057] However, it is not only possible to manufacture the first and second, or the third and fourth, parts from metal. The first, second, third, and / or fourth part can alternatively be made of plastic, for example, a polymer or a polymer composite.

[0058] In one embodiment, the lock cylinder has a coil spring for each tumbler-counter-tumbler pair. When using conventional counter-tumblers, such a counter-tumbler can have a recess at its end facing away from the keyhole to receive the respective coil spring.

[0059] In one embodiment, the lock cylinder has a housing, e.g. a sleeve, which encloses the stator, and each of the coil springs rests against an inner surface of the housing at its end facing away from the key opening.

[0060] The invention further relates to a device comprising one of the described locking cylinders and a tool. The tool can be used for programming the locking cylinder and can be designed as described in the present patent application. In particular, it can have a stop surface and at least one pin projecting from the stop surface. It can also have several pins projecting from the stop surface to the same extent.

[0061] The tool can be characterized by having at least one stop surface and at least one pin protruding from the stop surface, wherein the diameter and length of the at least one pin are adapted for programming the locking cylinder.

[0062] The method for programming a locking cylinder relates to a locking cylinder comprising a stator and a rotor rotatable within the stator, with a keyhole into which a key can be inserted, and which further comprises at least one tumbler having a first and a second part which are connected to each other in an interference fit. In the method, with the key inserted into the keyhole, the effective length of the tumbler is changed, in particular by a tool acting from outside the locking cylinder, especially when the key is fully inserted up to a key stop, so that each coding is positioned as intended relative to the corresponding tumbler-counter-tumbler pair, by pushing the first and second parts together or moving them apart, in particular by pushing them together.

[0063] In some embodiments, the tool has a stop surface and a mandrel protruding from the stop surface. The mandrel can also be called a rod and causes the first and second parts to slide together. The mandrel can be solid. However, it can also be hollow (or a hollow rod).

[0064] Such a tool can enable very precise programming, and it can be relatively easy to manufacture.

[0065] The contact surface can be designed to be flat. Alternatively, it can also have a curvature.

[0066] In one embodiment, the mandrel is guided into the stator until the stop surface abuts a counter stop and a force is exerted by the mandrel on the second part, causing it to slide together.

[0067] The aforementioned counter-stop is usually formed by a part of the lock cylinder. In particular, it can be formed by a housing surrounding the stator, for example, a sleeve, or more precisely, by an outer surface of the housing. It is also possible to provide that the counter-stop is formed by the stator itself (more precisely, by an outer surface of the stator).

[0068] The force mentioned can be directed in the direction of the key. In particular, the force can be directed along a bore axis of the bore in which (or which) the locking mechanism is located in the rotor.

[0069] It can be provided that the stop surface has a curvature that is adapted to a curvature of the counter stop.

[0070] The stator is encased in a housing (e.g., a sleeve), and the housing has (access) openings through which the mandrel can be inserted, allowing the mandrel to be inserted through the housing into the stator.

[0071] In one embodiment, a separation joint exists between the stator and the rotor, and a length of the mandrel measured from the stop surface is dimensioned such that, after the mandrel is inserted into the stator until the stop surface abuts the counter stop, the first and second parts are pushed into each other to such an extent that an end of the locking mechanism facing away from the key coincides with the separation joint.

[0072] In particular, if a counter-hold is adjacent to the locking mechanism, the first and second parts are pushed into each other to such an extent that a separation joint formed between the locking mechanism and the counter-hold lies at the separation joint between the stator and the rotor.

[0073] In particular, the tool acts indirectly (by pressing the counter-tumbler, or a part thereof, against the tumbler) or directly (by pressing on the second part) on the second part, while an inner end of the first part rests against the correspondingly coded key. If the interface between the tumbler and the counter-tumbler is thereby shifted to the plane of the interface between the rotor and stator, the lock cylinder is programmed. The tool itself carries no information about the coding; rather, this is transferred from the key to the lock cylinder in the described process.

[0074] This method enables simple and precise programming (individualization) of a lock cylinder, which is typically a generic lock cylinder beforehand. In particular, no specific tools are required for programming, nor does the cylinder need to be modified; in some cases, it doesn't even need to be disassembled but can be used fully assembled as a generic cylinder and adapted using the programming method described here.

[0075] If the counterhold is two-part and thus has a third and a fourth part, then, for example, the tool acts on the second part via the fourth part, i.e., the tool moves the fourth part inwards relative to the first part - while, for example, the third part is prevented from being moved inwards by the separation arrangement - and the fourth part moves the second part inwards relative to the first part, which can be equivalent to the second and first parts sliding into each other.

[0076] In one embodiment, a tool can be used in which a programming pen acts directly on the second part to position it at a distance from the fourth part – this is to define multiple parting lines so that a multi-component system (MCS) can be created. Additionally, the same tool or a separate tool can have mandrels that act on the fourth part in the manner described above.

[0077] Before and after programming, and therefore before and after the first and second parts are pushed together or moved apart, the two parts are connected in a press fit.

[0078] As stated above, the detailed description is limited to the case of reducing the effective closing length by (further) sliding the first and second parts together.

[0079] It is not strictly necessary for a counter-locking mechanism to be present during programming. Programming can also be carried out without a counter-locking mechanism. However, it can simplify the completion of the lock cylinder if a counter-locking mechanism, and possibly also a spring, is already present during programming.

[0080] The first and second parts can be pushed together, in particular, by applying a force acting in the direction of the key, so that the first and second parts are pushed together. In particular, the first part can abut against the key during this process.

[0081] Since the first and second parts are already intertwined (slid into each other) before programming, the aforementioned sliding of the first and second parts into each other during programming generally corresponds to a further sliding of the first and second parts into each other.

[0082] According to the invention, the locking cylinder with tumbler and associated counter-tumbler has a helical spring associated with the tumbler and the counter-tumbler, wherein, when the first and second parts are pushed together, the pin extends through at least a part of the helical spring, in particular extends completely through the helical spring.

[0083] A typical lock cylinder naturally has several tumbler-counter-tumbler pairs. The described procedure can easily be applied to lock cylinders with two or more tumblers, each with at least two parts.

[0084] It is possible to provide that the tumblers in a generic lock cylinder are all the same length.

[0085] Naturally, it is possible to combine the above-described design variants with one or more of the other described design variants, provided this is logically feasible. This also applies to combinations of features described for the process with features described for the locking cylinder, and vice versa.

[0086] It is also important to note that tools of the type described above do not need to have any programming-related coding. In other words, the tools for programming a lock cylinder are the same, regardless of which key the lock cylinder is to be programmed for (and by which means).

[0087] It is therefore possible, for example, to have a set of one or more tools available on-site (e.g., at a retailer) that is suitable for programming a specific type of (generic) lock cylinder. And with this tool set, any of these lock cylinders can then be programmed for use with any key (which, of course, is fundamentally suitable for that type of lock cylinder).

[0088] Alternatively, the use of a tool that is at least partially coded is also possible. Such a tool can, for example, have a base body that forms a stop and at least one programmed mandrel that protrudes from the base body to a programmable extent. The adjustment of such a mandrel can be done manually, for example via an adjusting screw, or electronically / automatically.

[0089] When using such a coded (programmable) tool, programming can be done without a key. The information used for programming the tool can also be used separately for manufacturing the key by applying the corresponding code, in a manner known per se.

[0090] In some embodiments, it is also possible to assemble the lock cylinder only during or after programming, for example, by not pre-assembling the locking elements – such as the two-part locking elements – and possibly the separation arrangements, but rather inserting them together with the corresponding mandrel of the tool, or inserting them after the – then programmable – tool has acted directly on the second parts. In embodiments of the second aspect, it may also be provided that the fourth parts, or the second and fourth parts, are inserted subsequently, for example, during or immediately before programming.

[0091] Further embodiments and advantages will become apparent from the dependent patent claims, the following description of exemplary embodiments and the figures.

[0092] The invention will now be explained in more detail with reference to exemplary embodiments and the accompanying drawings. These show: Fig. 1 a lock cylinder with key inserted, perspective view; Fig. 2 the lock cylinder made of Fig. 1 , in exploded view, perspective; Fig. 3 a locking-counterlock pair with spring, perspective; Fig. 4 the locking-counterlock pair of Fig. 3 , in section, perspective; Figs. 5-15 a locking cylinder in partial section, perspective, to illustrate the locking cylinder and its programming; Fig. 16 a two-part tumbler, schematic, in section; Fig. 17 a two-part tumbler, schematic, in section; Fig. 18 a two-part tumbler, schematic, in section; Fig. 19 a two-part tumbler, schematic, in section; Fig. 20 another embodiment of a generic locking cylinder in section; Fig. 21 the locking cylinder according to Fig. 20after the introduction of a coded key; Fig. 22 the firing cylinder after Figs. 20 and 21 during programming; Fig. 23 the locking cylinder after Figs. 20-22 after programming; Fig. 24 the locking cylinder after Fig. 20 during programming with a tool that allows programming of a lock cylinder which can be opened with different keys; Fig. 25 the lock cylinder according to Fig. 20 according to the programming Fig. 24 ; Fig. 26 a to the lock cylinder according Fig. 20 alternative locking cylinders during programming; Fig. 27 the locking cylinder after Fig. 26 after programming; and Figs. 28 and 29 each show a representation of a programmable tumbler-counter-tumbler pair with separation arrangement, for a locking cylinder according to one of the Figures 20-27 .

[0093] Parts not essential for understanding the invention are partially omitted. The described embodiments are exemplary of the subject matter of the invention or serve to illustrate it and do not have a limiting effect.

[0094] Fig. 1 The figure shows a perspective view of a lock cylinder 1 with a key 10 inserted. Fig. 2 shows the locking cylinder in an exploded view from a perspective perspective. Fig. 1 The lock cylinder 1 has a rotor 5 and a stator 6 as well as a sleeve 7. Instead of the sleeve 7, the lock cylinder 1 can have a different housing, or the housing can include, in addition to the sleeve, further parts, e.g., parts that at least partially surround the sleeve, which in Fig. 1 not shown.

[0095] As described above, a locking mechanism with at least two parts is proposed. An example of this is in Figs. 3 and 4depicted from a perspective perspective, in Fig. 4 cut.

[0096] The locking pin 2, together with a counter-locking pin 3 (and a coil spring 4, part of which is received in a recess 3a of the counter-locking pin 3), as well as with rotor 5 and stator 6, enables the conventional locking and unlocking function of the cylinder lock in a manner otherwise known. If the separation gap T2 formed by each locking pin-counter-locking pin pair coincides with the separation gap between rotor 5 and stator 6, rotor 5 can rotate within stator 6 and is unlocked. As long as the separation gap T2 of at least one locking pin-counter-locking pin pair lies elsewhere, rotor 5 is locked and cannot be rotated within stator 6.

[0097] Locking device 2 has a first part 2a and a second part 2b, which have an interference fit 2p. For example, the second (counter-locking side) part 2b can form a shaft 2i and the first (key-side) part 2a a guide 2j for the shaft 2i, so that the two parts 2a, 2b are displaceable relative to each other (while maintaining the interference fit).

[0098] As in the example of the Figures 3 and 4 As shown, the second part 2b, adjacent to the counter-hold, can be T-shaped or mushroom-shaped, and the first part 2a can be sleeve-shaped. The first part 2a has an end 2e by means of which a key inserted into the lock cylinder is scanned.

[0099] Figs. 5 to 15 The figures show a perspective view of a lock cylinder 1 in partial section, illustrating the lock cylinder 1 and its programming. For clarity, not all reference symbols are used in all figures.

[0100] Fig. 5 Figure 1 illustrates the interior of an unprogrammed, generic lock cylinder. The individual components have been described previously. The keyway is labeled 1a. All five depicted pin-tumbler pairs are of the same length and in the same radial position. The initial state can be equivalent for lock cylinders used with pin tumbler locks. For more complex lock cylinders used with reversible keys than the one shown, the length and orientation of the pin-tumbler pairs may differ.

[0101] Furthermore, the following only illustrates the case where the lock cylinder is already pre-assembled with tumbler-counter-tumbler pairs, spring 4, and sleeve 7 before programming. However, this is not mandatory. For example, sleeve 7, or sleeve 7 and counter-tumblers 3 (and springs 4), can alternatively be attached after programming.

[0102] Fig. 6 Figure 1 illustrates the insertion of a key 10, for which (and by means of which) the lock cylinder 1 is to be programmed. The length of the tumblers 2 remains unchanged, but their radial position changes when the key 10 is inserted, as can be seen at the separation joints T2, T2'. The stop 1b of the bore in Fig. 6 visible, which causes the tumblers 2 to be closed if key 10 is not introduced (cf. Fig. 5 ) not protrude too far into the keyhole.

[0103] In Fig. 7The key 10 is fully inserted. The length of the tumblers 2 remains unchanged, but their radial position (relative to the axis of the rotor) is now determined by the coding provided on the key 10, as can be seen at the parting lines T2, T2'.

[0104] A programming tool 9 is shown. It has several prongs 9a attached to a base plate, which forms a stop surface 9b. In the example shown, a counter-stop 8 for the tool 9 is formed by the outer surface of the sleeve 7.

[0105] In Fig. 7 It can also be seen that the mandrels 9a of the tool are inserted through openings in the housing (here the sleeve 7), and that the coil springs then surround the mandrels; the openings in the housing have a smaller diameter than the coil springs so that the latter can be supported on the inner surface of the housing.

[0106] As in Fig. 8 As can be seen, the mandrels 9a of the tool 9 are inserted through the sleeve 7 into the stator 6, each extending through the interior of one of the coil springs 4.

[0107] The arrow K is used in Fig. 9 A force K symbolizes the force by which the parts 2a and 2b, which are in a mutual press fit, are pushed together. This leads to the result shown in Fig. 9 noticeable shortening of the length of tumblers 2.

[0108] In Fig. 10 The stop surface 9b (of the tool 9) and the counter stop 8 (of the locking cylinder 1) are in contact with each other, so that no further force can be exerted by the tool 9 to push the two parts 2a, 2b of the tumblers 2 together. The locking cylinder 1 is now programmed. And the rotor 5 is unlocked. As from Fig. 10 As can be seen, all separation joints T2 of the locking-counterlocking pairs coincide with the separation joint T1 between rotor 5 and stator 6.

[0109] In Fig. 11 The figure shows that the tool 9 is removed again by pulling the pins 9a out of the lock cylinder 1. Fig. 12 It is no longer displayed.

[0110] In Fig. 13 The situation is illustrated when key 10 is turned slightly after the actual programming. The locking and locking pairs are separated from each other. Fig. 14 The key is turned a little further, and rotor 5 is no longer shown in section. Fig. 15 The key is turned a little further (number 10).

[0111] As has become clear from the above, the programming of the lock cylinder 1 can be very simple yet precise, and the tool used can also be easy to manufacture.

[0112] For complex locking cylinders with, for example, non-radial bores at different angles and of different lengths for the tumbler-counter-tumbler pairs, it may be necessary or useful to use an individual tool for each tumbler-counter-tumbler pair, or at least to use different tools for some of the tumbler-counter-tumbler pairs.

[0113] The tool(s) therefore carry no information about the coding of the lock cylinder. The coding of the lock cylinder is inherited from the key.

[0114] Fig. 16 The diagram schematically shows a two-part locking device 2 in cross-section. This locking device 2 corresponds to the one described in the... Figures 3 and 4as shown. The first part 2a is sleeve-shaped and forms (through an internal bore) an internal guide 2j for the shaft 2i of the second part 2b, which is T-shaped or mushroom-shaped. The first part 2a further has a stop 2c, through which (by interaction with the stop 1b, see Fig. 6 ) the locking device 2 is held in its bore and the locking device 2 is prevented from protruding too far into the key opening 1a.

[0115] However, many other geometries of two-part locking devices are also possible. Figures 16 to 19 Some examples show this.

[0116] In Figs. 16 to 19 For clarity, the first part 2a is represented by wider lines than the second part 2b. The effective length of the locking pins 2 is marked with L.

[0117] In Fig. 16The dotted lines symbolize a second position of the second part 2b and the corresponding (shortened) effective closing length L, as may be the case, for example, after the programming of the locking cylinder.

[0118] The interlock 2 of Fig. 17 is similar to that of Fig. 16 . But in this case, the guidance of the second part 2b in the bore is better, which, however, entails a more complex manufacturing of the second part 2b.

[0119] In the examples of Figs. 18 and 19 An inner guide is formed by the second part 2b, while a shaft guided therein is formed by the first part 2a.

[0120] In the case of Fig. 18 The attack 2c will be as in Figs. 16 and 17 formed by the first part 2a. However, this results in a small wall thickness of the sleeve-shaped second part 2b.

[0121] If, as in Fig. 19Since the stop 2c is provided on the second part 2b, the wall thickness of the sleeve-shaped second part 2b can be greater, so that the second part 2b can be quite robust. However, this can simplify the optical readability of the encoding.

[0122] Regarding the choice of material, some details have already been given above. For example, bronze can be chosen for the first part 2a and brass for the second part 2b. Typical dimensions are maximum tumbler diameters: between 2 mm and 3 mm, and shank or guide diameters between 1 mm and 1.6 mm, with a (diameter-related) interference fit of between 0.015 mm and 0.04 mm. Other materials and dimensions are conceivable.

[0123] An example of a lock cylinder 1 is shown in Fig. 20The following figures depict the rotor 5, the stator 6 with locking lugs 2 and counter-locks 30 in their initial position (in which the bores of the rotor and stator are aligned and in which the key can be inserted or removed) in section. For the sake of simplicity, the housing, on which, for example, springs acting on the counter-lock (not shown in these figures) are supported externally, is not shown. As explained in the preceding examples, such a housing can have openings for the mandrels of the tool.

[0124] In Fig. 20 The generic, programmable locking cylinder is shown in its initial, unprogrammed configuration and without a key shaft inserted into the key channel 1a. Figures 28 and 29 Each shows a tumbler-counter-tumbler pair with a separation arrangement for a locking cylinder as in Fig. 20and depicted in the following figures Fig. 29 in an exploded view (where elements 41, 42, 43 of the separation arrangement 40 are drawn next to each other, although they may, for example, be designed as separate elements).

[0125] In contrast to the above embodiments, the locking cylinder 1 has, in addition to the two-part tumblers 2, also two-part counter-tumblers 30, which can be seen in Figures 28 and 29 looks particularly good. The programmable interlock-counterlock pairs (in Fig. 20(All ten pairs shown are programmable pairs; however, combinations with conventional tumbler-counter-tumbler pairs are also conceivable.) They are constructed as follows: the first part 2a of the tumbler has an inner end 2e that projects into the keyway 1a. On its outer surface, it has a sleeve-like section forming an outwardly open opening, which serves as a guide 2j for the second part 2b. The second part is designed as an inner part that can be guided inside the sleeve-like section and, in its initial configuration, is inserted into the guide 2j only at its inner end. Because the dimensions of the first and second parts are matched to create an interference fit, the second part 2b is fixed relative to the first part 2a.

[0126] The counterholds 30 also have a third, outer part 30a and a fourth, inner part 30b. The fourth part 30b is guided in the first part 30a, which for this purpose is designed as a sleeve with a through opening. The dimensions of this through opening are matched to the outer dimensions of the fourth part such that an interference fit is also achieved between these parts. The through opening of the third part 30a can be widened outwards, so that, regardless of the position of the fourth part 30b, an opening 30d limited at the bottom is formed (in the arrangement according to Fig. 28 a circumferential groove) into which a helical spring of the type described above can engage, which rests on the outside against an inner surface of a housing surrounding the stator of the type also described above.

[0127] In the examples shown, the fourth part itself is also sleeve-shaped, with an inner opening 30c extending in the direction of the bore axis. This design is optional and, in some embodiments, serves the purpose of programming a "Master Key System" (MKS), which will be explained in more detail below.

[0128] A separation arrangement 40 is provided between the first part 2a and the third part 30a. This arrangement comprises a plurality of separation elements 41, 42, 43, between each of which a separation joint is formed. The thickness of the separation elements (measured in the direction of the bore axis) corresponds to the difference between two adjacent possible coding depths of coding bores of the key (which here is designed as a flat key / reversible key; if the invention is implemented with a serrated key, the thickness corresponds to the distance between two adjacent possible coding levels of the serration profile) provided in the entire locking system.

[0129] The separation elements can be fixed relative to both the second part 2b and the fourth part 30b, also by means of an interference fit, by having a continuous opening whose inner diameter is matched to the outer diameter of the first and fourth parts. Accordingly, after programming, the separation elements can be configured as either interlocks or counter-interlocks, depending on the configuration.

[0130] Furthermore, fixing the separation elements relative to the locking or counter-locking mechanism is not necessary at all; rather, they can, for example, be arranged loosely relative to the locking / counter-locking mechanism, since their function during programming lies in defining the distance between the first and third part, and the position of the separation elements relative to the locking and counter-locking mechanism is already defined by the arrangement.

[0131] In the initial configuration, all separation elements 41-43 are fixed to the second part 2b.

[0132] In the illustrated embodiment, the separation elements 41, 42, 43 are designed as perforated discs. Alternatively, they can initially form a single-piece element with predetermined separation points corresponding to the parting lines. Other geometries, e.g., slotted rings, are also possible; an inside-outside reversal is also possible (i.e., the second and fourth parts are each sleeve-shaped, and the first and third parts as well as the separation arrangement are guided in these sleeves), whereby in the latter case openings for the mandrels of the tool are provided in the (in Figures 20 (not shown) housings may need to be adapted and may, for example, be crescent-shaped.

[0133] Fig. 21 shows the lock cylinder Fig. 20After the insertion of a key 10, the locking pins and counter-locking pins are displaced outwards by different amounts according to the key's coding, against the spring force of the springs (not shown). In this configuration, the lock cylinder is ready to be programmed according to the coding of the inserted key 10.

[0134] Fig. 22 The programming is shown. A tool 9 with pins 9a is positioned relative to the lock cylinder such that the pins 9a protrude into the bore, and then pressed against the cylinder until a stop surface 9b abuts a corresponding stop surface of the cylinder (in Fig. 22 formed by the outer surface of the stator; alternatively, also by a surface of the housing (not shown).

[0135] The pins 9a act on the fourth part, which is pressed further in relative to the bore, unless this is due to a particularly deep coding bore of the key (as in Fig. 21 The fourth part (30b) is already so deep in the bore (at position P1) that the corresponding mandrel (9a) cannot reach it. The fourth part (30b) is displaced inwards relative to the third part by the pressure force, thereby pushing the second part inwards relative to the first part. Due to the contact with the wrench (10) or the separation arrangement (40), the first and third parts are prevented from being displaced inwards.

[0136] The length of the mandrels 9a is matched to the dimension of the fourth part in such a way that, when the tool is pressed in to the stop, the parting line between the second and fourth parts – which forms the parting line between the mandrel and the counter-mandrel – is aligned with the parting line between the rotor and stator for all locking-counter-mandrel pairs, which can be seen in Fig. 22 looks good. Since at each coding depth of the coding bore there is a separation joint between the separation order 40 and the first 2a or the third part 30b or between elements 41, 42, 43 of the separation arrangement, this is both a sufficient and necessary condition for the rotor 5 to be able to be rotated relative to the stator 6 when the key 10 is inserted.

[0137] In Fig. 22Two tools 9 are shown, one for each of the depicted coding series. However, it is also perfectly acceptable to work with only one tool even when multiple series are present, as is usually the case with flat keys; the tool is then used sequentially for programming the different series.

[0138] For the engagement of the mandrels of tool 9, the housing surrounding the stator (e.g. sleeve; in Figs. 20-27(Not shown) For each bore in the stator, an opening aligned with it has a smaller diameter than the bore but a larger diameter than the respective mandrel of the tool, so that a stop surface for the helical spring is formed and the mandrel can still act on the fourth part 30b through this opening. The diameter of the mandrel is, if necessary, larger than the diameter of the inner opening 30c of the fourth part 30b, but it is smaller than the diameter of the helical spring and the fourth part 30b.

[0139] Fig. 23 shows the programmed lock cylinder after the key 10 has been removed. In order for the lock cylinder to be operated by turning the rotor 5, the key 10 or a key of identical construction must be inserted so that all separating joints between the second and fourth elements are positioned accordingly.

[0140] It is often necessary for lock cylinders to be operated by several different keys to grant different access rights, for example, for a main entrance and apartment doors, for a master key, or for more complex, different hierarchical levels. For this purpose, purely mechanical locks require at least some of the pin-tumbler pairs to have multiple separation points to allow operation by different keys, and / or pin-tumbler pairs must be omitted entirely.

[0141] Systems with locking cylinders that can be opened by several different keys are referred to here as MKS systems. The following section describes them using the... Figures 24-27 Two possibilities are presented which - besides the trivial solution of simply omitting tumbler-counter-tumbler pairs - make the inventive locking cylinders suitable for MKS systems as well.

[0142] Fig. 24 shows a lock cylinder which, in its initial configuration, is the same as that of Fig. 20 This corresponds to a setup analogous to during programming. Fig. 22 In contrast to the version according to Fig. 22 However, the tool 9 has a more complex design. In addition to the mandrels 9a, it has a plurality of programming pins 90, which are guided coaxially through the tool with the locking and counter-locking bore and can be guided through the inner opening 30c of the fourth part 30b as well as through the inner opening of the separation arrangement 40 and can thus act directly on the second part 2b.

[0143] In the illustrated embodiment, the tool 9 is equipped with a programming pin 90 per mandrel, but this is optional: if it is known in advance at which position the locking-counterlocking pair is to have multiple separating edges, it is also possible to equip only those positions. As a further alternative, the functions of the mandrels 9a and the programming pins 90 can also be implemented by two different tools that are applied one after the other, or the same tool can be used twice in succession, once without programming pins and once with programming pins.

[0144] The programming pins 90 are adjustable (in the illustrated embodiment relative to the body and the mandrels 9a of the tool) such that they protrude into the bores to different depths and, when the tool is guided to the stop 9b, push the second parts 2b inwards to different depths. In particular, they can push a second part 2b further inwards than it was pushed by the fourth part 30b by the action of the mandrel 9a, so that in this case the second part lies at a defined distance from the fourth part. This can also be seen in Fig. 25 good, which shows the situation after removing tool 9 and pulling off the key.

[0145] In the illustrative example shown, the distance at position P1 is, for example, two units (one unit is the difference between two adjacent possible defined coding depths of coding holes of the key, corresponding to the distance between two adjacent separation joints of the separation arrangement 40, here corresponding to the thickness of one of the separation elements 41, 42, 43), at position P5 three units, at position P3 one unit, and at positions P2 and P4 there is no distance at all.

[0146] Where a gap is programmed between the second and fourth parts, there are several possible separation points between the locking and counter-locking components; the separation elements in the space can optionally remain in the bore of the locking or counter-locking component when the rotor is rotated relative to the stator - similar to a so-called "split pin" as known in conventional mechanical locking systems with MKS function.

[0147] The number of separation joints per locking-counterlock pair is a+1, where a is the distance measured in the units mentioned.

[0148] The programming means acting directly on the second part - here programming pins 90 - thus make possible a locking cylinder which has at least one tumbler-counter-tumbler pair which has a plurality of separating joints, as is required for locking systems with MKS function.

[0149] Fig. 26This shows an alternative approach in which individual locking-counterlock pairs – in the example shown, the two pairs in relation to the key opening are located furthest inside, i.e., furthest left in the illustration of Fig. 26 - not programmable, but designed as pairs of conventional locking pins 22 and counter-locks 23, with a split pin 24 in between. The split pin 24 - or possibly several split pins per bore pair - can be formed in different thicknesses, as is known per se, and thus have different split lines corresponding to defined coding depths of the respective bore on the key. The construction and programming of the remaining locking pin-counter-lock pairs is as described above. Figs. 20-23 described. Fig. 27 shows the lock cylinder 1 after programming.

[0150] In contrast to the previously described embodiments, the choice of key coding for a lock cylinder is according to Figs. 26 and 27 not freely selectable; rather, the codings are predetermined at the positions of the conventional locking-counterlock pairs, which are generally already fitted by the cylinder manufacturer, whereby, as is known from MKS systems, several different codings fit - depending on the selected locking, counterlock and split pin(s).

[0151] The conventional MKS locking pin and counter-locking pin pairs can optionally be identical in all locking cylinders of a series of locking cylinders and thus also be supplied as generic cylinders, but offer an MKS function through their design.

[0152] Systems with MKS function according to the principle of Figures 26 and 27They exhibit, in particular, an MKS function and are nevertheless programmable with the simplest tool; thus, they combine the MKS functionality of known systems with programmability by the simplest tool according to the embodiments of the Figures 1-23 .

Claims

1. A locking cylinder, having a stator (6) and a rotor (5), which is rotatable in the stator and has a key opening (1a) into which a key (10) can be inserted, and a plurality of tumbler / counter-tumbler pairs, wherein at least one of the tumblers has a first and a second part (2a, 2b) which are connected to one another and whose relative position can be adjusted and fixed, having an access for a tool, through which the tool can act on the tumbler in a fully assembled state of the locking cylinder, wherein the first part (2a) and the second part (2b) are connected to one another in a press fit and the locking cylinder is programmable by way of the tool (9), which exerts a thrust force on the counter-tumbler or directly on the tumbler in order to displace the second part relative to the first part, while a key with a desired coding is inserted into the cylinder and forms an internal stop for the tumbler dependent on the coding, characterised in that the locking cylinder has a coil spring (4) assigned to the tumbler and the counter-tumbler as well as a housing (7) encasing the stator, wherein the coil spring (4) rests against an inner surface of the housing with an end facing away from the key opening, and in that the housing has an access opening through which the mandrel (9a) of the tool (9) can be passed in order to displace the second part (2b) relative to the first part (2a), wherein the mandrel (9a) of the tool (9) extends through at least a part of the coil spring when the first and second parts are pushed into one another.

2. The locking cylinder according to claim 1, wherein the access is formed by one access opening per tumbler / counter-tumbler pair with a two-part tumbler.

3. The locking cylinder according to one of claims 1-2, wherein a stop for limiting a movement of the tumbler into the key opening is formed by the first part.

4. The locking cylinder according to one of claims 1-3, having the combination of a plurality of programmable tumbler / counter-tumbler pairs, in which at least the tumbler has a first (2a) and a second part (2b) which can be brought into different positions relative to one another and can be fixed in these positions, with at least one MKS tumbler / counter-tumbler pair, in which the tumbler (22) and the counter-tumbler (23) each have a predefined length and in which at least one split pin (24) is present between the tumbler (22) and the counter-tumbler (23).

5. A device comprising a locking cylinder according to one of claims 1-4 as well as a tool (9) having a stop surface and at least one mandrel (9a) protruding from the stop surface, in particular wherein the tool has a plurality of mandrels protruding from the stop surface to exert the thrust force, in particular wherein the tool has a plurality of mandrels (9a) protruding equally far from the stop surface.

6. A method for programming a locking cylinder according to one of claims 1-5, having a stator and a rotor, which is rotatable in the stator and has a key opening into which a key can be inserted, and further having at least one tumbler which has a first and a second part which are connected to one another in a press fit and whose relative position can be adjusted and fixed, wherein, when the key is inserted into the key opening, a locking-effective length of the tumbler is changed by pushing the first and second parts into one another by means of a tool, which tool, in the assembled state of the locking cylinder, exerts a thrust force on the counter-tumbler or directly on the tumbler by way of an access, and wherein, when pushed into one another, the key serves as a counter-stop for the first part in such manner that the axial position of the first part relative to a bore axis of a bore in the rotor, in which the tumbler is guided, depends on a coding of the key.

7. The method according to claim 6, wherein the pushing of the first and second parts into one another is carried out by means of the tool (9), which has a stop surface (9b) and a mandrel (9a) protruding from the stop surface, wherein the mandrel (9a) is guided into the stator until the stop surface rests against a counter-stop and a force is exerted on the second part by the mandrel, which causes the parts to be pushed into one another.

8. The method according to claim 6 or 7, wherein the mandrel (9a) is guided through an access opening in a housing surrounding the stator.

9. The method according to one of claims 6 to 8, wherein the locking cylinder has a counter-tumbler (3, 30) assigned to the tumbler and a coil spring (4) assigned to the tumbler and the counter-tumbler, wherein when the first and second parts are pushed into one another, the mandrel (9a) extends through at least a part of the coil spring.