The invention relates to an electrically energized cylinder lock.

BACKGROUND

A lock of this type is known from practice and is described in, for example, US 6,865,916 B2. In the known lock, there are included in the inner knob an electromagnetic coil, permanent magnets, a compression spring, and a power supply in the form of a battery. With the aid of an operating rod movable in axial direction and extending through a rotatable inner plug, which is nonrotatably connected with an inner knob, a coupling element can connect the inner plug with a rotatable outer plug, which outer plug is nonrotatably connected with an outer knob. Between the coupling element and the outer plug, there is also a compression spring. The spring constant of the compression spring in the inner knob and the spring constant of the compression spring between the coupling element and the outer plug are accurately tuned to each other, so that with the aid of the electromagnetic coil and the permanent magnets, an assembly is obtained which can bring the operating rod in two stable positions, whereby in a first stable position of the operating rod the outer knob is freely rotatable so that the lock cannot be operated and whereby in a second stable position of the operating rod the outer knob is coupled via the outer plug and the coupling element with the inner plug so that the lock is also operable with the outer knob. The

movement of the operating rod is effected by a brief electrical energization of the electromagnetic coil. As a result of the fact that the known lock involves two stable positions, the electromagnetic coil needs to be energized only briefly, so that power is only consumed to bring the operating rod from the first stable position to the second stable position and vice versa. DE 10065155 also shows an electrically energized lock, where, with the aid of an electrically energized control element movable in axial direction, two blocking elements, for example balls, are pressed outwardly in radial direction for obtaining a coupled condition in which an outer rotary knob is nonrotatably connected with the carrier of the lock. In an uncoupled condition, the axially movable control element is in a retracted position, so that the two blocking elements are in a radially inwardly moved position.

WO2012004734 shows an electronic lock with an actuator rotatable by an electric motor, with which blocking balls can be forced into a coupling condition in which these balls are in a radially outwardly moved position. The rotatable actuator can also be brought in a rotational position in which the balls can move into a radially inwardly moved position, so that an uncoupled condition is effected. SUMMARY

A drawback of the lock known from US'916 is that it contains relatively many parts and consequently is costly. Another drawback is that the energization is done with a relatively complicated assembly of a coil and permanent magnets as well as a number of springs with spring constants accurately tuned to each other. In connection with the size of the coil and the required magnetic force, the lock housing itself provides insufficient space to accommodate the coil and the magnets. Hence, these parts are received for a large part in the inner knob.

The invention contemplates an electrically energized cylinder lock whereby at least some of the above-mentioned drawbacks are at least partly solved. More particularly, the invention contemplates an electrically energized cylinder lock whose operation preferably fits into the inner plug of a euro cylinder, that is, has a diameter of less than 13 mm, and where use can be made of a standard direct -current motor, which are available at low costs. Obviously, the invention also envisages that the life of the battery or accumulator for energizing the lock be as optimal as possible. Finally, manipulation of the lock by unauthorized individuals, as by vibration, by use of magnets, or by rotating the outer knob at high speed, should not result in the opening of the lock.

To this end, the invention provides a lock according to claim 1.

More particularly, the invention provides a cylinder lock comprising:

• a lock housing provided with a cylindrical lock housing bore;

• a carrier which is provided with a carrier cam and which is rotatable relative to the lock housing;

· a substantially cylindrical inner plug with which the carrier is

nonrotatably connected, wherein the cylindrical inner plug is received in the lock housing bore in a manner rotatable around an axial axis, wherein the cylindrical inner plug is provided with an inner plug chamber;

· an inner knob or inner handle which is nonrotatably connected with the cylindrical inner plug or is an integral part thereof;

• a substantially cylindrical outer plug which is received in the lock housing bore in a manner rotatable around the axial axis and which is provided with at least one blocking recess;

· an outer knob or outer handle which is nonrotatably connected with the outer plug or is an integral part thereof;

• a coupling mechanism which is switchable into a coupled condition in which the outer plug is nonrotatably connected with the cyhndrical inner plug and an uncoupled condition in which the outer plug is freely rotatable relative to the cylindrical inner plug;

• an electric motor provided with a rotatable output shaft which is operatively connected with the coupling mechanism for operating the coupling mechanism;

wherein the coupling mechanism comprises:

· a blocking assembly including: o a control element which is received in the cylindrical inner plug in a manner rotatable around the axial axis and includes a control part with a circumferential contour of which a part has a relatively large diameter and another part has a relatively small diameter; and

o at least one blocking element which is received in a transverse bore which extends in an end part of the cyhndrical inner plug, which end part has a smaller diameter with respect to the remaining part of the cylindrical inner plug, the transverse bore extending perpendicular to the axial axis;

wherein, in a first rotational position of the control element which is the blocking position, the at least one blocking element abuts against the part of the circumferential contour of the control element with the relatively large diameter, so that the at least one blocking element is in a radially outwardly located position in which it extends partly outside the circumference of the end part of the cylindrical inner plug and thereby engages the outer plug, such that the outer plug is nonrotatably connected with the cylindrical inner plug;

wherein, in a second rotational position of the control element which is the unblocking position, the at least one blocking element abuts against the part of the circumferential contour of the control element with the relatively small diameter, so that the at least one blocking element is in a radially inwardly located position in which it extends within the circumference of the end part of the cylindrical inner plug so that the outer plug is rotatable relative to the

cylindrical inner plug; and

wherein the coupling mechanism further comprises:

• a transmission which operatively connects the control element with the rotatable output shaft of the electric motor. As the at least one blocking element needs to move in radial direction to bring the coupling mechanism from the coupled to the uncoupled position and as the blocking element, moreover, is deep into the lock housing, moving the blocking elements with the aid of a magnet for the purpose of unauthorized operation of the cylinder lock from outside is not possible. Also sabotaging the cylinder lock in a different manner is particularly difficult because the electric motor is set up near the inner knob or inner handle and because unauthorized approach of the substantially cylindrical inner plug from the outside is hindered by the outer plug which in the uncoupled position is freely rotatable relative to the substantially cyhndrical inner plug. The various parts of the lock, including the electric motor and the coupling mechanism, can be configured to be so small that these parts fit into the substantially cylindrical inner plug, which substantially cylindrical inner plug has outside dimensions that match a standard cylinder lock, such as defined, for example, in DIN 18252, that is, a substantially cylindrical inner plug having an outside diameter of 13 mm. Moreover, the number of parts can be minimized and use can be made of a standard commercially available electric motor. As a result of the low number of parts and as a result of the possibility of utilizing a standard electric motor, a relatively low-cost cylinder lock can be manufactured that, moreover, is highly robust and reliable.

In an embodiment, the cylinder lock may be configured in the manner as described in claim 2. More particularly, the transmission may include a driving assembly which includes a first driving assembly element which is nonrotatably connected with the output shaft of the electric motor. The driving assembly may then include a second driving assembly element which is operatively connected with the first driving assembly element and which is rotatable by the first driving assembly element between two stable end positions. A first of the two stable end positions may then be a coupling position and a second of the two stable end positions an uncoupling position. Further, in such an embodiment, the transmission may include a torsion spring element which by a first end is nonrotatably connected with the second driving assembly element and which by a second end is nonrotatably connected with the control element, such that:

• in the coupling position of the second driving assembly element the torsion spring element exerts a rotational force on the control element that pushes the control element in the direction of the blocking position;

• in the uncoupling position of the second driving assembly element the torsion spring element exerts a rotational force on the control element that pushes the control element into the unblocking position.

The coupling mechanism having a thus-implemented transmission with torsion spring element provides in a simple manner the advantage of the low electrical power consumption for bringing the cylinder lock into and holding it in the uncoupled and coupled position, as a result of use being made of a driving assembly with two stable positions and of a torsion spring element that allows the at least one blocking element not to move directly into the radially outwardly located position when the outer plug is not in a position such that the at least one blocking element can be received in a blocking recess. In this intermediate phase, the energy supplied by the electric motor is temporarily stored in the torsion spring element as built-up torsion spring tension. As soon as the outer plug does have a position where the at least one blocking element can be received in a blocking recess, the control element will rotate further under the influence of the torsion spring tension and the at least one blocking element will move to the radially outwardly located position and be brought into engagement with the blocking recess in the outer plug.

Further embodiments of the invention are described in the subclaims and will hereinafter, with reference to the figures, be further clarified. BRIEF DESCRIPTION OF THE FIGURES

Fig. 1 shows an example of a cylinder lock in perspective view;

Fig. 2 shows a similar perspective view of the cylinder lock in exploded view;

Fig. 3 shows another perspective view of the cylinder lock in exploded view;

Fig. 4 shows a perspective view of the cylindrical inner plug with a carrier secured thereon;

Fig. 5 shows a similar perspective view of the cylindrical inner plug to that represented in Figure 4, in exploded view;

Fig. 6 shows the cylindrical inner plug in the exploded view of Figure 5 in perspective from another viewpoint;

Fig. 7 shows the cylindrical inner plug with the coupling mechanism in an uncoupled condition;

Fig. 8 shows the cylindrical inner plug in a condition where the coupling mechanism has been energized but where the control element has not fully rotated a quarter turn yet and the blocking elements have not been fully moved outwards in radial direction yet because the outer plug was not in the appropriate position for that yet, the torsion spring element is under tension in this condition;

Fig. 9 shows the cylindrical inner plug in a condition where the control element, under the influence of the tension in the torsion spring element, has rotated further and the blocking elements have been moved outwards in radial direction, so that a nonrotatable coupling between the inner plug and the outer plug has been effected;

Fig. 10 shows a top plan view of the example of the cylinder lock shown in the preceding figures; and

Fig. 11 shows a cross-sectional view along line XI-XI of Figure 10. DETAILED DESCRIPTION

In the following detailed description, the cylinder lock according to the invention as well as various embodiments thereof are described with reference to the figures. While the detailed description contains reference numerals which refer to the figures, the figures merely show an example and the exemplary embodiments may also be embodied in a different way. The reference numerals therefore serve for clarification only and the exemplary embodiments that are described in the detailed description are not in any way limited to the example shown in the figures. Just as for the claims, it also holds for the detailed description that the reference numerals do not in any way limit the detailed description.

The cylinder lock 10 comprises a lock housing 12 which is provided with a cylindrical lock housing bore 14. Further, the cylinder lock 10, as is clearly represented in Figure 2, has a carrier 16 which is provided with a carrier cam 18 and which is rotatable relative to the lock housing. With the aid of the carrier cam 18, a mechanism in a door lock is energized, which allows a door bolt to be operated in a well known manner. The cylinder lock 10 includes a substantially cylindrical inner plug 22 with which the carrier 16 is nonrotatably connected. The cylindrical inner plug 22 is received in the lock housing bore 14 and is rotatable around an axial axis L. The cylindrical inner plug 22 is provided with an inner plug chamber 24 which is visible in, for example, Figures 7-9 and 11. The cylinder lock 10 further comprises an inner knob or inner handle 26 which is nonrotatably connected with the cylindrical inner plug 22 or which is an integral part of the inner plug 22. In addition, the cylinder lock 10 includes an outer plug 72 which is received in the lock housing bore 14 in a manner rotatable around the axial axis L and which is provided with at least one blocking recess 74. Further, the cylinder lock 10 comprises an outer knob or outer handle 28 which is nonrotatably connected with the outer plug 72 or which is an integral part of the outer plug 72. With the aid of a switchable coupling mechanism 30, the outer plug 72, in coupled condition of the coupling mechanism 30, is nonrotatably connected with the cylindrical inner plug 22. In an uncoupled condition of the coupling mechanism 30, the outer plug 72 is freely rotatable relative to the cylindrical inner plug 22. The cylinder lock 10 has an electric motor 32 which is provided with a rotatable output shaft 34 which is operatively connected with the coupling mechanism 30 for operating the coupling mechanism 30. The coupling mechanism comprises a blocking assembly including a control element 36 which is received in the cylindrical inner plug 22 in a manner rotatable around the axial axis and which includes a control part 38 with a circumferential contour of which a part has a relatively large diameter and another part has a relatively small diameter. Further, the blocking assembly includes at least one blocking element 40 which is received in a transverse bore 42 which extends in an end part 22a of the cylindrical inner plug 22. The transverse bore 42 extends perpendicular to the axial axis L. The end part 22a concerned has a smaller diameter with respect to the remaining part of the cylindrical inner plug 22. The at least one blocking element 40 abuts against the control element 36. In a first rotational position of the control element 36 which is the blocking position, the at least one blocking element 40 abuts against the part of the

circumferential contour of the control element 36 with the relatively large diameter, so that the at least one blocking element 40 is in a radially outwardly located position in which it extends in part outside the

circumference of the end part 22a of the cylindrical inner plug 22. In that radially outwardly located position, the at least one blocking element 40 engages in an above-mentioned blocking recess 74 of the outer plug 72, such that the outer plug 72 is nonrotatably connected with the cyhndrical inner plug 22. In a second rotational position of the control element 36 which is the unblocking position, the at least one blocking element 40 abuts against the part of the circumferential contour of the control element 36 with the relatively small diameter, so that the at least one blocking element 40 is in a radially inwardly located position in which it extends within the

circumference of the end part 22a of the cylindrical inner plug 22. In that radially inwardly located position, the at least one blocking element 40 is not in engagement with the outer plug 72, so that the outer plug 72 is freely rotatable relative to the cyhndrical inner plug 22. As a result, the carrier 16 cannot be rotated with the outer plug 72 and hence the cylinder lock 10 cannot be operated with the outer plug 72. The coupling mechanism 30 further comprises a transmission 44 which operatively connects the control element 36 with the output shaft 34 of the electric motor 32.

This assembly of features of the cylinder lock according to the invention provides the advantages described in the summary of the

invention set out above, which is considered inserted here and to which reference is made.

As is common and also visible in Figures 5 and 6, the electric motor

32 comprises a motor housing 32a and, received therein, a rotor 32b which is nonrotatably connected with the output rotation shaft 34. In the example represented in the figures, the outer knob 28 is an integral part of outer plug 72. However, the invention is not limited to this. Just as has been shown with the inner plug 22 and the inner knob 26, also the outer knob or outer handle 28 and the outer plug 72 may be implemented as two parts which are nonrotatably connected with each other. This nonrotatable connection is preferably form -closed and may comprise, for example, a square, hexagonal or like polygonal hole in the outer plug and a correspondingly shaped pin which is nonrotatably connected with the outer knob or outer handle 28, or forms an integral part thereof. In an alternative implementation, the outer plug 72 may be provided with a rectangular or hexagonal pin and the outer knob 28 may be provided with a rectangular or hexagonal hole in which said pin is receivable. Further, the example shown in the figures has a lock housing 12 with a substantially constant circumferential contour extending in an axial direction. The lock housing is further provided with a lock housing recess 20 which divides the lock housing 12 in a first and the second lock housing part. The carrier 16 is received in the lock housing recess 20. In a first position of the carrier, the carrier cam 18 is in the lock housing recess 20 between the first and the second lock housing part and the carrier cam 18 is furthermore, viewed in axial direction of the lock housing 12, within the circumferential contours of the lock housing 12. Through rotation, the carrier 16 is

positionable in a second position in which the carrier cam 18, viewed in axial direction, extends outside the circumferential contours of the lock housing 12. However, the invention is not limited to a thus-implemented lock housing with recess 20 and two lock housing parts. Essential is only that the lock housing 12 is provided with a cylindrical lock housing bore 14 and that the cylinder lock 10 has a carrier 16 with carrier cam 18 which is rotatable relative to the lock housing 12. Instead of an integrally configured lock housing 12 as shown in the figures, it is also possible that the two lock housing parts are separate parts which are mutually, in a known manner, interconnected via a bridge.

In an embodiment, of which an example is shown in the figures, the transmission 44 can comprise a driving assembly which includes a first driving assembly element 46 which is nonrotatably connected with the output shaft 34 of the electric motor 32. The driving assembly may further include a second driving assembly element 48 which is operatively

connected with the first driving assembly element 46 and which is rotatable by the first driving assembly element 46 between two stable end positions. A first of the two stable end positions is hereinafter designated as coupling position and a second of the two stable end positions is hereinafter

designated as uncoupling position. Further, the transmission 44 comprises a torsion spring element 50 which by a first end is nonrotatably connected with the second driving assembly element 48 and which by a second end is nonrotatably connected with the control element 36. In the coupling position of the second driving assembly element 48, torsion spring element 50 exerts a rotational force on the control element 36 that pushes the control element 36 in the direction of the blocking position. In the uncoupling position of the second driving assembly element 48, the torsion spring element 50 exerts a rotational force on the control element 36 that pushes the control element 36 in the unblocking position.

By application of the torsion spring element 50, the electric motor 32 needs to be electrically energized only for a very brief moment to bring the second driving assembly element 48 from the uncoupling position (see Fig. 7) to the coupling position (see Figures 8 and 9). Even when the at least one blocking element 40 as a consequence of a rotational position of the outer plug 72 cannot be pressed into the radially outwardly located position and hence the control element 36 cannot make the full quarter turn (see Figure 8), the second driving assembly element 48 can be fully rotated from the uncoupling position to the coupling position (see Figure 8). The torsion spring element 50 in that situation comes to be under some torsion spring tension so that on the control element 36 continuously a rotational force is being exerted in the direction of the blocking position associated with the desired radially outwardly located position of the at least one blocking element 40. As soon as the outer plug 72 is turned, the at least one blocking element 40 will move into a blocking recess 74 present in the outer plug 72 under the influence of the force exerted by the torsion spring element 50 when the respective recess comes into line with the at least one blocking element 40. The at least one blocking element 40 is then in the radially outwardly located position as represented in Figure 9. As a consequence of this construction, as already noted before, the electric motor 32 only needs to be energized very briefly, so that the consumption of electric power is limited to a minimum and therefore the life of the battery or accumulator is optimal.

The example of the drive shown in the figures is only an example. There are many other kinds of bistable driving constructions conceivable. Of relevance is that with a simple, standard commercially available electric motor 32 a second driving assembly element can be brought from a first stable position into a second stable position. This can also be effected, for example, with a snap construction whereby, for example, a spring-mounted ball can snap into two recesses, with each recess defining a stable rotational position of the second driving assembly element. Possible options also include the use of link systems or other cam/curve assemblies for creating two stable positions for the second driving assembly element.

The torsion spring element 50 may also be configured differently than shown in the figures. In the figures there is a torsion-loadable helical spring involved which extends over a certain length. However, in an alternative implementation of the torsion spring element, use can be made of a flat spiral spring. It is also possible that use is made of a torsion spring element in the form of a flexible plastic or rubber cord or a twisting leaf spring.

In an embodiment, of which an example is shown in the figures, the first driving assembly element 46 can comprise a crank pin 52 which is set up eccentrically with respect to the axial axis L and is rotatable around the axial axis L. The second driving assembly element 48 may then be rotatable around a second axis L2 which extends parallel to the axial axis L and is positioned eccentrically with respect to the axial axis L. In this embodiment, the second driving assembly element 48 is provided with a guide slot 54 in which the crank pin 52 is slidably received.

This construction is relatively simple and robust and is drivable with a standard electric motor 32 which is available at a relatively low cost price and which, moreover, can have a diameter that is so small that this electric motor 32 fits in the inner plug chamber 24 of the inner plug 22, which inner plug 22 in turn has an outside diameter that is fittingly, rotatably receivable in a standard lock housing 12 of a cylinder lock 10, for example according to DIN 18252. This in contrast to the known electrically energized locks which are operated either with an electromagnetic coil or with a motor that is set up outside the lock housing 12, for example, in the inner knob of the lock, as shown in US 6,865,916 B2. The present embodiment provides a particularly compact construction with a minimum of parts, so that the costs are relatively low and, moreover, the construction is particularly durable.

In an embodiment, of which an example is shown in the figures, the second driving assembly element 48 may be provided with a radial arm 56 which extends in radial direction with respect to the second axis L2, with the guide slot 54 also extending in said radial direction in the arm 56.

In such an embodiment, the crank pin 52, upon transition from the coupling position to the uncoupling position of the second driving assembly element 48, moves from a radially inwardly located position of the guide slot 54 to a radially outwardly located position and then to the radially inwardly located position again. The radially outwardly located position essentially forms a dead center that has to be passed to bring the second driving assembly element 48 from one stable position, for example, the uncoupling position, to the other stable position, for example, the coupling position. By the presence of the dead center that has to be passed, there are effectively two stable extreme positions involved, with the associated advantage of low consumption of electrical power that has been described above. It is noted that the invention is not limited to an embodiment with such construction of crank pin 52 and radial arm 56 with guide slot 54 to provide two stable positions. Possible options also include other mechanisms, utilizing, for example, springing pins or spring-mounted balls that fall into associated recesses to provide two stable positions. Instead of a crank pin 52/guide slot 54 mechanism, also a link system may be used. The crank pin 52/guide slot 54 mechanism, however, provides the advantage that it can be made of robust construction and enables relatively simple assembly.

In an embodiment, of which an example is shown in the figures, the first and second stable end positions of the second driving assembly element 48 may be defined by a blind end of the guide slot 54. Both in the first and in the second stable end position, the crank pin 52 then abuts against the blind end of the guide slot 54, so that further rotation of the second driving assembly element 48 is limited. In an alternative

implementation, the first stable end position of the second driving assembly element 48 may be defined by a part of the radial arm 56 that abuts against an inner wall of the inner plug chamber 24. The second stable end position of the second driving assembly element 48 may then be defined also by a part of the radial arm 56 that abuts against the inner wall of the inner plug chamber 24.

For neither of the above-described alternative embodiments for providing the two stable end positions do any special provisions or elements need to be provided to define the two end positions. In effect, they are defined either by the length of the guide slot 54, that is, the position of the bhnd end thereof, or by the diameter of the inner plug chamber 24 in combination with the length and shape of the radial arm 56. With such an embodiment, the number of parts can therefore be kept to a minimum.

In order to provide for simple assembly of the cylinder lock 10, an embodiment, of which an example is shown in the figures, may include a first assembly part 58 which has a cylindrical circumferential wall 60 and an end wall 62 with a central opening 63 and which is fittingly received in the inner plug chamber 24, such that the control element 36 is rotatably received in the central opening 63 in end wall 62 and is enclosed between the end wall 62 of the assembly part 58 and an end wall of the cylindrical inner plug 22.

In an embodiment, of which an example is shown in the figures, the second driving assembly element 48 can be simply assembled utilizing a second assembly part 64. The second assembly part 64 can have a

cylindrical circumferential wall 66 and at least one end wall 68 and be fittingly received in the inner plug chamber 24. The end wall 68 is then provided with a round hole 70 whose center coincides with the second axis L2, and the second driving assembly element 48 being rotatably received in the round hole 70.

For the purpose of clarity, the two assembly parts 58, 64 are not shown in Figures 7-9 because they would obstruct the view of the driving assembly elements 46, 48, the torsion spring 50 and a part of the control element 36. In Figures 5, 6 and 11, however, the assembly parts 58, 64 are clearly visible.

In an embodiment, of which an example is shown in the figures, the end part of the cylindrical inner plug 22 with the transverse bore 42 may be fittingly received in an end of the substantially cylindrical outer plug 72. The blocking recesses 74 are implemented as a number of grooves, provided near the end of the substantially cylindrical outer plug 72 in an inner wall thereof and extending in axial direction, in which the at least one blocking element 40 engages when the control element 36 is in the blocking position.

By not limiting the number of grooves to just one pair of two diametrically opposed grooves, but opting, for example, for six pairs, the outer plug 72 needs to be rotated only through a small angle, in this example about 25° at a maximum, to effect engagement of a blocking element 40 in the nearest blocking recess 74 after the electric motor 3 has been energized for bringing the second driving assembly element 48 in the coupling position and thereby pushing the control element 36 in the direction of the blocking position. Accordingly, a user who wishes to operate the cylinder lock 10 from the outside in that case feels a non-operative angular displacement of the outer plug 72, and the associated outer knob or outer handle 28, of 25° at a maximum. For that matter, the number of blocking recesses may also be chosen to be lower or even considerably higher than the example of twelve (six pairs) mentioned here. For the purpose of a simple axial fixation of the outer plug 72 in the lock housing 12, in an embodiment, of which an example is shown in the figures, the outer plug 72 may be provided with a circumferential groove 76. A locking pin 78 included in the lock housing 12 may then extend into the circumferential groove 76, such that the outer plug 72 is fixed in axial direction with respect to the lock housing 12.

In an embodiment, of which also an example is shown in the figures, the inner knob or inner handle 26 may be provided with a hollow cylindrical shaft 80 which is rotatably received in the lock housing bore 14. An end of the hollow cylindrical shaft 80 of the inner knob or inner handle 26 is then nonrotatably connected with the cylindrical inner plug 22. This nonrotatable connection makes it possible for the inner plug 22 and hence the carrier 16 to be always rotated with the aid of the inner knob or inner handle 26. In an alternative implementation, the inner knob 26 may be provided with a square or hexagonal pin or a pin of a different polygonal cross section. The substantially cylindrical inner plug 22 may then be provided with a square or hexagonal hole in which the pin is nonrotatably receivable. It is also possible, of course, for the inner knob 26 to be provided with a square or hexagonal hole and for the substantially cylindrical inner plug 22 to be provided with a square or hexagonal pin on which the inner knob 26 with square or hexagonal hole is mountable.

In an embodiment, the inner knob or inner handle 26 may be provided with a chamber 82 in which a battery or accumulator and control electronics for the electric motor 32 are received. The battery or accumulator and the control electronics for the electric motor 32 are not shown in the figures, but it is clear to one skilled in the art how these could be arranged in the inner knob or inner handle 26. Since little power is needed to be able to operate the cylinder lock 10, a relatively small battery can suffice. Also, the control electronics for the electric motor 32 can be made of particularly small design, so that the chamber 82 can be relatively small and the esthetics of the inner knob or inner handle 26 need not be adversely affected thereby.

In an embodiment, the control electronics can comprise a wireless receiver for receiving a wireless signal which is emitted, for example, by a smartphone or a transponder the user has available.

When the lock is approached, a signal from the smartphone or the transponder of the user may be recognized and the coupling mechanism may be automatically operated to push the control element 36 in the direction of the blocking position, so that, as soon as the user rotates the outer plug 72, the nonrotatable coupling between the inner plug 22 and the outer plug 72 is effected and the door lock can be opened.

Similarly to the outer plug 72, for the purpose of the simple assembly of the inner knob or inner handle 26, in an embodiment, of which an example is shown in the figures, also the hollow cylindrical shaft 80 of the inner knob or inner handle 26 may be provided with a circumferential groove 84. A locking pin 86 which is included in the lock housing 12 can then extend into the circumferential groove 84, such that the inner knob or inner handle 26 is fixed in axial direction with respect to the lock housing 12. In an alternative embodiment, the circumferential groove 84 may also be provided in the substantially cyhndrical inner plug 22, and the inner knob 26 may be connected with the inner plug via a pin/hole connection. Pin and hole are preferably of unround configuration, so that a nonrotatable, form-closed connection between the inner knob 26 and the inner plug 22 can be effected.

The above-mentioned nonrotatable connection between the hollow cylindrical shaft 80 of the inner knob or inner handle 26 and the cyhndrical inner plug 22 may, in an embodiment, be implemented as a form -closed connection. This may be realized, for example, in that at least a part of the outer contour of the cylindrical inner plug 22 is provided with a flattened portion 88 and in that a part of the inner contour of the hollow cylindrical shaft 80 includes a flattening 90 which, in mounted condition, fittingly abuts against the flattened portion 88 of the outer contour of the cylindrical inner plug 22. Instead of a single flattened portion, of course, it is also possible to use a plurality of flattened portions. The outer contour of the cylindrical inner plug 22 may be implemented, for example, as a hexagon, and the hollow cylindrical shaft 80 may be provided with an inner hexagon. The cylinder lock 10 may be provided with a locking pin or locking screw 92 which effects a connection between the inner knob or inner handle 26 and the cylindrical inner plug 22.

The carrier 16 may be similarly nonrotatably connected with the substantially cylindrical inner plug 22, viz., form-closed with at least two mutually corresponding flattened portions 94, 96 and possibly with addition of a locking pin or locking screw 98.

In an embodiment, of which an example is shown in the figures, the at least one blocking element 40 may be implemented as two balls.

However, possible options also include other embodiments, such as, for example, two radial movably arranged locking pins or pivotable cams. Balls, however, have the advantage that they are robust and cannot be simply vandalized with a drilling operation for obtaining unauthorized access via the cylinder lock 10. Also, use can be made of a single ball 40 or a singly implemented locking pin instead of the two balls 40 shown in the figures.

The various embodiments described hereinabove may be applied independently of each other and combined with each other in different ways. The reference numerals in the detailed description and the claims do not limit the description of the embodiments and the claims and are for clarification only.