EP2816181B1 - Door lock - Google Patents

Description

The invention relates to a door lock with the features of the preamble of claim 1.

The invention relates to a door lock as it is known for apartment doors. A normal door lock is nowadays regularly a mortise lock, which is inserted into a door leaf from the side. Mortice locks have previously completely displaced conventional box locks. In principle, however, the teaching of the invention also applies to box locks or other types of locks. Door locks in this sense are also locks for other closure elements such as flaps or gates.

The most important data of a door lock are backset, face length and face width, the size of the nut and the door direction left or right. The size of the nut here means the size of the square recess in the lock nut. Usual are square openings of 8 mm, 9 mm or 10 mm. The corresponding pusher pins have corresponding dimensions (see keyword "door lock" in Wikipedia).

Normal door locks are operated manually. But also motorized door locks are known. Also known are manually or motor-locked door locks.

A normal door lock on the one hand has a latch, which is spring-biased in the locked position, but can fall back on it when slamming a door provided with the door lock due to a wedge and does not hinder the closing of the door. On the other hand, a normal door lock usually has a lock bolt, which can be adjusted by a lock cylinder with a rotation of the lock cylinder from an unlocked position into a locking position, possibly with two turns in a further advanced locking position and then stops there. The revolutions of the lock cylinder are called tours, thus there are door locks with one-door locking, those with two-speed locking or, mostly with multiple locks, even with multi-speed locking.

In the course of the teaching of the present invention, a locking element may be both a lock latch and a lock bolt.

Also known asymmetrically designed door locks, the locking element can be operated, for example, only from the inside of the lock box. From the outside of the lock case, an actuation of the locking element is not possible in this example, for example, because there is only a fixed knob attached

The door lock from which the present invention is based ( DE 20 2006 005 337 U1 ), is universally applicable and has a motor operation. The lock nut of the door lock is designed here in two parts, it is divided transversely to its axis of rotation in one of the outside of the lock case facing outer part and one of the inside of the lock case facing inner part. These two parts are rotatably mounted in the lock case so that they are independently rotatable. Each of the parts is connectable with a pusher shaft for a door handle so that torque is transmitted from the corresponding part of the lock nut on this pusher shaft. In other words, an inserted into the part of the locknut pusher shaft is rotatably connected to this part of the locknut. This can usually be done in the manner known per se via a polygonal, in particular square opening in the lock nut. The corresponding pusher shaft is then a typical square pin.

With regard to the effect on the locking element, the construction known here is designed so that only one of the two parts, preferably the inner part, is coupled with the locking element in terms of drive technology. Only when this part of the lock nut is rotated, the locking element moves. When the other part of the lock nut is rotated, the locking element normally does not move.

The door lock can be switched by providing a switchable coupling for the two parts of the lock nut in the lock case. This coupling can be actuated from the outside in such a way that the two parts of the lock nut are coupled in a torque-transmitting manner in the engaged state. Then follows the part of the lock nut coupled here, the rotational movement of the drive-technically coupled with the locking element part of the lock nut and vice versa.

The clutch is in the disengaged state, so coupled to the second part pusher shaft can be rotated without resulting in an effect on the locking element. One of the outside of the lock box assigned Door handle runs empty, the door lock can not be opened by pressing this door handle. Regardless, the door lock but can always be opened from the inside of the door handle associated, because the relevant inner part of the lock nut is always coupled drive-technically with the locking element.

The well-known, previously described door lock has an electronic control that is remotely controllable wirelessly and brings the clutch in the Einkuppfungszustand via the electric actuator in accordance with the signal of a transponder upon receipt of an allowable authorization code. Other functionalities does not have the well-known door lock.

The teaching is based on the problem to expand the Fuhktionalitäten the known, previously explained door lock.

The aforementioned problem is solved in a door lock with the features of the preamble of claim 1 by the features of the characterizing part of claim 1.

The design of the door lock according to the invention takes into account a potential fire in a building in which a door is secured with this door lock. In case of fire, the room temperature at the location of the door lock increases rapidly. This is used according to the invention to control the electric actuator from the electronic control so that the clutch reaches the Einkupplungszustand so that the door can then be opened from both sides. For this purpose, the invention provides that a temperature sensor or thermal switch is arranged in the lock case at a heat from the outside preferably easily accessible location. The temperature sensor or thermal switch is control technology connected to the controller and these are all designed so that when the temperature at the temperature sensor or thermal switch exceeds a previously predetermined limit, the clutch, triggered by the controller, is brought by means of the actuator in the engagement state.

Preferred embodiments and further developments of the door lock according to the invention are the subject of the dependent claims.

Another focus is the adjustment of the locking element itself. Provided is preferably an electric locking drive for adjusting the locking element. Of importance for the invention is that the electric locking drive engages with a one-way freewheel in such a way on the locking element, that the locking element is always unhindered by the electric locking drive in the unlocked position can be brought.

This ensures that even when using the electric locking drive for the latch or, alternatively or additionally, also for a lock bolt, always a manual movement of the locking element is possible in the unlocked position. This can then be done easily with a latch if the door provided with the door lock is slammed or if the latch is operated from the door handle: manually.

Fig. 1

eine perspektivische Ansicht eines bevorzugten Ausführungsbeispiels eines erfindungsgemäßen Türschlosses mit einem Schlosskasten, dessen die Außenseite definierendes Schlossblech dargestellt ist, dessen die Innenseite definierende Abdeckung jedoch aus Gründen der Darstellbarkeit weggelassen worden ist,

Fig. 2

das Ausführungsbeispiel aus Fig. 1 in einer Ansicht von der Innenseite her,

Fig. 3

eine Ansicht des Türschlosses von rechts in Fig. 2,

Fig. 4

eine ausschnittweise Schnittdarstellung des Türschlosses aus Fig. 3,

Fig. 5

eine Teildarstellung des Bereichs der Schlossnuss des Türschlosses aus Fig. 2, die Kupplung im Auskupplungszustand, und

Fig. 6

eine Teildarstellung des Bereichs der Schlossnuss des Türschlosses aus Fig. 2, die Kupplung im Einkupplungszustand.

In the following, the invention will now be explained in more detail with reference to a particularly preferred embodiment, in which all variants of the teaching of the invention are realized. Serve the drawings described below, In the drawings shows

Fig. 1

a perspective view of a preferred embodiment of a door lock according to the invention with a lock case, the outside of the defining lock plate is shown, the inside of the defining cover has been omitted for illustrative purposes,

Fig. 2

the embodiment Fig. 1 in a view from the inside,

Fig. 3

a view of the door lock from the right in Fig. 2 .

Fig. 4

a partial sectional view of the door lock Fig. 3 .

Fig. 5

a partial view of the area of the lock nut of the door lock Fig. 2 , the clutch in the disengaged state, and

Fig. 6

a partial view of the area of the lock nut of the door lock Fig. 2 , the clutch in Einkupplungszustand.

The figures of the drawing show in connection a preferred embodiment of a door lock according to the invention. This door lock can be seen in Fig. 1 in a somewhat perspective inclined representation. As usual, this door lock has first a lock case 1, which here has an outside of the lock box 1 forming lock plate 2 and left thereof a right angle to the lock plate 2 extending cuff 3, with such a door lock, which is shown here as a mortise, in a corresponding inclusion of a door is bolted. Below the lock case 1 is a profile cylinder, which is shown here as a dummy cylinder 4.

In the lock case 1 is a locking element 5, which is between an extended locking position ( Fig. 1 ) and a retracted unlocking position (from Fig. 1 starting shifted to the right) is adjustably mounted. This adjustment is made here by a move. In principle, it is also possible and known as such from the prior art not to move such a locking element 5, but to pivot. This occurs, for example, in multiple locking, if not the lock latch shown here, but a lock bolt, as explained above, is concerned as a locking element 5.

This locking element 5 is spring-biased in the locking position, namely by a return spring 6. Since this is concretely a lock latch, this would be the trap spring in the terminology of the lock technology.

Fig. 1 . 2 . 5 . 6 show, moreover, in different representations, another component of this door lock, namely a lock nut 7 rotatably mounted in the lock case 1, which is drive-coupled with the locking element 5.

In the illustrated embodiment, the drive-technical coupling of the lock nut 7 with the locking element 5 is an angle lever 8. This has an upper lever arm 9, which is force-transmitting on one side with the locking element 5, and a Federanschlussarm 10, to which a strong tension spring 11 is connected, which presses the angle lever 8 with its lever arm 9 without any other force against a limit stop 12. The tension spring 11 thus holds the angle lever 8 and with it the lock nut 7 so far when it is coupled to the angle lever 8, in a certain starting position. This corresponds to the normal, unactuated position of a door handle when such is connected via a trigger shaft to the door lock.

Out Fig. 1 . 3 and 4 results in a further feature of the present door lock such that the lock nut 7 is divided transversely to its axis of rotation in one of the outside of the lock case 1 facing outer part 13 and the inside of the lock case 1 facing inner part 14 which are mounted in the lock case 1 such that they are independently rotatable. Each of the parts 13; 14 is connected to a pusher shaft 16; 16 for a door handle torque transferable connectable. Only one of the two parts 13; 14, here and preferably the inner part 14, is drivingly coupled to the locking element 5. In the lock case 1 is a switchable coupling 17 for the two parts 13; 14 of the lock nut 7. The clutch 17 is operable from the outside so that the two parts 13; 14 of the lock nut 7 in the coupling state torque transmitting coupled and uncoupled in the disengaged state from each other.

In the perspective view of Fig. 1 one sees only schematically this structure. More precisely one recognizes the construction in Fig. 3 to Fig. 6 ,

The first part 13 of the lock nut 7, in the illustrated and preferred embodiment, but of course not restrictive to understand the outer part 13, from a non-illustrated in the drawings door handle, starting at the moment with this outer part 13 torque engaging engaged pusher shaft 15 at any time to be turned around. However, this rotation has no effect due to the coupling 17 on the locking element 5 when the clutch 17 is in the disengaged state. Then the rotation is empty, an actuation of the door handle is then ineffective.

Then, when the clutch 17 is in the Einkupplungszustand, the two parts 13; 14 of the locknut 7 coupled torque transmitting each other. If then the outer part 13 is actuated, takes the outer part 13 with the interposition of the coupling 17, the inner part 14 of the lock nut 7 with. This is turned on. Therefore, the locking element 5 is then adjusted, in particular displaced by the angle lever 8 in the illustrated embodiment.

The representation in particular in Fig. 5 and 6 shows that because of this construction of the door lock, a second tension spring 18 is provided, which cooperates only with the inner part 14 of the lock nut 7. It has the same direction of action as the tension spring 11 and also serves to hold a correspondingly coupled door handle without actuation in the correct position. However, since the lock nut 7 is divided according to the invention, not a tension spring, but it must be a total of two tension springs 11; 18 be present, each acting on a part 13 or 14 of the lock nut 7 and the connected pusher shafts 15 and 16 and corresponding door handle.

In Fig. 5 and 6 can be seen in a special, to be explained later in detail exemplary embodiment of the coupling 17, whose function. Fig. 5 shows the disengagement state. The two parts 13; 14 of the lock nut 7 are independent of each other and can each be rotated for sidh. Fig. 6 shows the engagement state. By in the in Fig. 5 recognizable gap at the edge of the lock nut 7 inserted component are the parts 13; 14 of the lock nut 7 rotationally fixed, so torque transmitting, coupled together. If a part 13 or 14 is rotated, the other part 14 or 13 is synchronously rotated.
In this way, in the disengaged state, the door lock in the door can act as a locked door, although in fact the door can always be opened from the inside without further ado
It is provided that the coupling 17 can be actuated by means of an electric actuator 19 arranged in the lock case 1. This electric actuator 19 can be seen particularly well in the Fig. 2 . 5 and 6 , He will be described in more detail later.
Of course, the clutch 17 may additionally be manually operated. This would be realized, for example, with a shift switch on the inside of the lock case 1.
The illustrated embodiment shows a particularly preferred embodiment for the coupling 17 such that the coupling 17 on each of the two parts 13; 14 of the lock nut 7 has a driver 20. In the illustrated and preferred embodiment ( Fig. 5 . 6 ) is the driver 20 as a ring-like projection on the corresponding part of the lock nut 7 with a defined Gap executed. The gaps between the two drivers 20 of the two parts 13; 14 of the lock nut 7 are usually aligned one above the other.

To clutch 17 also includes an adjustable with respect to the drivers 20 coupling element 21. This is already described in its basic design part in Fig. 5 right bottom offset to the lock nut 7 shown. Fig. 5 shows the disengagement state, the coupling element 21 does not collide with the drivers 20. In contrast, in the engaged state, Fig. 6 , The coupling element 21 is in the gaps formed by the drivers 20 and thereby couples the two drivers 20 rotatably with each other. Will now the parts 13; 14 of the lock nut 7 are rotated so they are coupled together rotationally fixed Consequently, the coupling element 21 moves with rotation of the lock nut 7 with. It keeps the coupling state of the driver 20 upright.

The exact construction of the coupling 17 can of course be realized in various ways. The illustrated embodiment is only one such kind.

In the illustrated embodiment, but also here only preferred, the adjustable coupling element 21 is mounted radially outwardly of the driver 20 on a dome slider 22 limited circular arc adjustable. The dome slider 22 in turn is mounted radially adjustable relative to the drivers 20. By adjusting the dome slider 20 in the radial direction so the clutch 17 is actuated.

The construction described above can be seen particularly well in Fig. 5 and Fig. 6 , Fig. 5 shows the disengagement state. The dome slider 22 is retracted to the bottom right, the coupling element 21 is disengaged from the drivers 20. In Fig. 6 the dome slider 22 has been advanced in a fitting 23 obliquely left above. In this case, the coupling element 21 has come into engagement with the drivers 20 and couples them.

The dome slider 22 of the clutch 17 can be seen by dashed lines indicated a circular arc-shaped displacement guide for the coupling element 21. Is the coupling element 21 in the in Fig. 6 shown position, ie in Einkupplungszustand, the coupling element 21 follows on a circular arc of the limited rotational movement of the parts 13; 14 of the lock nut 7 and thus correspondingly proceeding rotational movement of the driver 20. This circular arc Movement of the coupling element 21 in the dome slider 22 is smooth and unhindered. It is limited by the design-dictated pivot angle covered by the door handle.

The door lock has an electric actuator 19 for the clutch 17. In the illustrated and preferred embodiment, it is provided that the electric actuator 19 is arranged with the adjustable coupling element 21 and the dome slider 22 also present here in a common mounting part 23 in the castle costs 1. The already mentioned built-in part 23 also forms the guide of the dome slider 22.

In Fig. 5 and 6 one sees the actuator 19 at the bottom right in the mounting part 23, here with a drive pinion 19 'and a rack 19 "connected here with the dome slider 22 Fig. 5 the rack 19 "is retracted to the bottom right, the dome slider 22 is in the uncoupling position Fig. 6 If the toothed rod 19 "is moved to the top left, it has moved the dome slider 22 to the top left and set the coupling element 21 into the drivers 20.

Of course, you can choose other constructions for the design and arrangement of the electric actuator 19, for example with a planetary gear, as a direct spindle drive or electromagnetically as a solenoid drive. The illustrated embodiment has proven to be particularly robust and expedient.

Preferably, the coupling 17 is bistable, so once engaged and disengaged without an external force exercise the respective state inherently stable. At the very least, it should be provided that the clutch 17 retains the engaged state in an inherently stable manner, so that only a positive actuation with corresponding exertion of force transfers the clutch 17 into the decoupling state. In any case, this design ensures that, in the event of an emergency, a clutch 17 in the engaged state remains in this state, for example in the event of a power failure of the electric actuator 19, so that the door can be opened from both sides.

A modification possibility is also to design the construction so that in case of power failure, the clutch 17 is adjusted in any case in the Einkupplungszustand.

Combined with Fig. 3 and 4 has already been explained that with each of the two parts 13; 14 of the lock nut 7 own pusher shaft 15; 16 is torque-transmitting engaged (as shown in the figures) or engageable (regularly the pusher shaft is designed as a plug-in pin). It is important that the two pusher shafts 15; 16 are arranged coaxially with each other and aligned. Show that Fig. 3 and Fig. 4 ,

Preferably, the two pusher shafts 15; Although not rotatably connected to each other 16, but not completely separated from each other in the axial direction. That would be possible, the length of the storage of the respective pusher shaft 15; 16 in part 13; 14 of the locknut 7 would be very short. Consequently, one realizes in the present case in the axial direction a quasi-continuous pusher shaft characterized in that here the two Drüdkerwellen 15; 16 are firmly connected in the direction of their common longitudinal axis, although they are freely rotatably connected to each other about the longitudinal axis against each other. Fig. 3 and 4 show a particularly preferred embodiment in that the one pusher shaft 15 has a central, axially extending frontal bore 15 'and the second pusher shaft 16 in the bore 15' accurately inserted retractable extension 16 '. The extension 16 'is defined in the bore 15' by means of a grub screw 15 ".

So that each of the two pusher shafts 15; 16 in each associated part 13; 14 of the lock nut 7 is axially just right, is the insertion depth of the respective pusher shaft 15; 16 in the respective part 13; 14 of the lock nut 7 by means of an axial fixing element, here in the form of a respective snap ring 24, set.

The illustrated and preferred embodiment shows in Fig. 1 and 2 even more peculiarities of the door lock shown here.

First of all, an electric locking drive 25 for adjusting the locking element 5 is provided here. The electric locking drive 25 engages with a one-way freewheel on the locking element 5 in such a way that the locking element 5 is always freely from the electric locking drive 25 in the unlocked position can be brought. The freewheel is here by a slot 26 in the locking element 5 forming latch (realized only in this embodiment, a SchlosSriegel can be so) in connection with the attached on the lock plate 2 pin-like limit stop 12.

The electric locking drive 25 is designed here in a particularly advantageous manner similar to the actuator 19, which has already been explained above. Here it is namely provided that this locking drive 25 is designed as a gear / rack drive with a drive pinion 27 and an extendable rack 28. The latter shows in particular Fig. 2 ,

In principle, it is structurally possible to arrange the electric locking drive 25 in a stationary manner on the lock case 1. He would then be connected to the locking element 5 in only one adjustment force-transmitting. In the opposite direction, the locking element 5 could always move freely.

The illustrated embodiment shows a contrast kinematic reverse construction in such a way that the electric locking drive 25 is arranged on the locking element 5 and adjustable with this and is connected to the lock case 1 in only one adjustment force transmitting. You can see in Fig. 2 the rack 28, which protrudes to the left a little from the housing of the locking drive 25. This rack 28 is supported on the left stump on the inside of the faceplate 3 from. Now, if the locking drive 25 is set in motion, the electric motor of the locking drive 25 rotates the drive pinion 27, which in Fig. 2 This pushes the rack 28 to the left against the faceplate 3. This is in the opposite direction, the housing of the locking drive 25 and with him here the locking element 5 shifted to the right, against the spring force of the return spring 6. The locking element 5 forming latch of the here is shown in Fig. 2 pushed to the right.

By this construction it is ensured that the door lock according to the invention also has a lock opening function, so it can be opened by an electric motor. This is of considerable importance for many applications.

This in Fig. 2 illustrated and so far preferred embodiment shows only dashed lines indicated that an electronic control 29 is arranged for the door lock in the lock case 1. The electronic control 29 can be operated by wire. However, an embodiment in which it is provided that the electronic controller 29 can be operated remotely wirelessly is particularly preferred. For this you can all known in the prior art ways of Realize remote control, especially a radio remote control. It is also expedient to operate by means of near-field detection (RFID).

For wireless remote operability, the illustrated and preferred embodiment may include an antenna. The antenna may for example be integrated in the dummy cylinder 4.

The controller 29, which in Fig. 2 can be clearly seen, with a variety of compounds, each of which is shown in dashed lines, connected to the corresponding components of the door lock control technology. An accumulator located in the door lock is not shown, the line leading to it is only hinted at.

For easy controllability by means of the controller 29, it is recommended to provide suitable limit switches for the various moving components, if necessary. These limit switches are not shown in the drawings. Typical limit switches work with Hall sensors, for example. However, limit switches can also monitor the motor current of a drive motor and identify an end position from a current increase.

End position switch can provide for the means of the locking drive 25 adjustable locking element 5, for both end positions, as well as for the two parts 13, 14 of the locknut 7. Then it can be easily determined whether the two parts 13, 14 are such that the gaps formed by the associated drivers 20 are in overlap. Then, the coupling element 21 can retract the dome slider 22 in the gaps 20 formed by the drivers. Only when the associated limit switches indicate this position of the parts 13, 14, the actuator 19 can be controlled.

Fig. 2 shows the inventive design of the illustrated door lock. This takes into account a potential fire in a building where a door is secured with this door lock. In case of fire, the room temperature at the location of the door lock increases rapidly. This is used according to the conception shown here to control the electric actuator 19 so that the clutch 17 reaches the Einkupplungszustand so that the door can be opened from both sides. For this purpose, it is provided that a temperature sensor or thermal switch 29 'is arranged in the lock case 1 at a location which is preferably easily accessible from outside for the action of heat, that the temperature sensor or thermal switch 29 'is control technology connected to the controller 29 and that the temperature sensor or thermal switch 29' and the controller 29 are designed so that when the temperature at the temperature sensor or thermal switch 29 'exceeds a previously predetermined limit, the clutch 17 triggered by the controller 29 can be brought into the coupling state rsp. is brought. The design takes into account the possibility with a temperature sensor, so that the evaluation of the measured temperature value is completely in the controller 29, or with a thermal switch 29 ', in which the temperature limit is stored in the switch and transmits to the controller 29 only a corresponding switching signal becomes.

If the door lock according to the invention is equipped with at least one current consumer, that is, for example, an electric actuator 19 and / or an electric locking drive 25 and / or an electronic control 29, then one must think of the power supply. Of course, this can basically be achieved by batteries or rechargeable batteries. For this purpose, the door lock could have a connection for a mains charger. This is still better than a fixed wiring of the door lock.

Also in this regard, a special construction is provided, which is also realized in the illustrated and preferred embodiment. It is in fact provided here that the locking element 5 is designed as a power supply element for a power supply of the lock case 1 and provided for this purpose with two electrical contacts 30, with electrical mating contacts 31 on a stationary counterpart 32, in particular on a strike plate, in live contact can be brought. You can see that in Fig. 1 in the interaction of mating contacts 31 and contacts 30 while in Fig. 2 only the contacts 30 on the locking element 5, here on the latch, sees.

If you work with a low-voltage power supply, so preferably with 12 V to 24 V, so there is no contact problem. If a door equipped with a door lock according to the invention is closed, then the electrical contacts 30 in the locking element 5 abut against the electrical mating contacts 31 on the stationary counterpart 32 on the door frame, in particular on the strike plate. In this state, an accumulator in the lock case 1 of the door lock can be supplied with power via the corresponding supply lead, so that it is charged. This is done by itself, without any special handling by a user. In this way it is possible, the invention Door lock to perform self-sufficient. It can simply be built into a door instead of an existing door lock without having to change anything on that door.

If you want to realize the described power supply, so you have to modify only slightly accessible to the lock plate something to install the stationary counterpart 32 with the electrical mating contacts 31 there and to wire.

Overall, it is of particular advantage that the dimensions of the new built-in components are so small that the dimensions of a normal lock case 1 can be met for classic door locks. By way of example applies to the dimensions of a door lock according to the invention that the lock case 1 a box height of 120 to 200 mm, preferably from 150 to 160 mm, and / or a box width of 60 to 100 mm, preferably from 80 to 90 mm, and / or a box thickness of 10 to 30 mm, preferably from 12 to 20 mm, in particular from 13 to 15 mm. LIST OF REFERENCE NUMBERS 1 lock case 27 pinion 2 latch plate 28 rack 3 faceplate 29 electronic control 4 blind cylinder 30 electrical contacts 5 locking element 31 electrical mating contacts 6 Return spring 32 stationary counterpart 7 lock follower 8th bell crank 9 lever arm 10 Federanschlussarm 11 mainspring 12 limiting stop 13 Outer part of 7 14 Inner part of 7 15 Pusher shaft of 13 15 ' drilling 15 " grub screw 16 Pusher shaft of 14 16 ' renewal 17 clutch 18 second cylinder 19 actuator 19 ' pinion 19 " rack 20 takeaway 21 coupling member 22 dome slide 23 fitting 24 snap ring 25 locking drive 26 Long hole

Claims (12)

1. Door lock comprising
   a lock case (1) which defines an inside and an outside, a locking element (5) which is mounted in the lock case (1) such that it can be adjusted, in particular moved, between an extended locking position and a retracted unlocking position, in particular a lock latch, and
   a follower (7) which is rotatably mounted in the lock case (1) and is coupled in drive terms to the locking element (5),
   wherein the follower (7) is split, transversely in relation to its rotation axis, into an outer part (13) which faces the outside of the lock case (1) and an inner part (14) which faces the inside of the lock case (1), which outer part and inner part are mounted in the lock case (1) in such a way that they can be rotated independently of one another,
   wherein each of the parts (13; 14) can be connected in a torque-transmitting manner to a handle spindle (15; 16) for a door handle,
   wherein only one of the two parts (13; 14), preferably the inner part (14), is coupled in drive terms to the locking element (5),
   wherein a switchable coupling (17) for the two parts (13; 14) of the follower (7) is provided in the lock case (1), and
   wherein the coupling (17) can be operated from outside in such a way that the two parts (13; 14) of the follower (7) are coupled in a torque-transmitting manner in the coupled-in state and are decoupled from one another in the uncoupled state,
   wherein the coupling (17) can be operated by means of an electrical actuating drive (19) which is arranged in the lock case (1),
   wherein an electronic controller (29) for the door lock is arranged in the lock case (1), the said electronic controller preferably being wirelessly remotely controllable,
   characterized
   in that a temperature sensor or a thermal switch (29') is arranged in the lock case (1) in a location which can be preferably easily reached from outside for the action of heat,
   in that the temperature sensor or thermal switch (29') is connected in control terms to the controller (29), and in that the temperature sensor or thermal switch (29') and the controller (29) are designed such that, when the temperature at the temperature sensor or thermal switch (29') exceeds a prespecified limit value, the coupling (17), in a manner triggered by the controller (29), can be moved or is moved to the coupled-in state by means of the actuating drive (19).
2. Door lock according to Claim 1, characterized in that the coupling (17) can also be manually operated.
3. Door lock according to Claim 1 or 2, characterized in that the door lock is provided with batteries or rechargeable batteries as the power supply means.
4. Door lock according to one of the preceding claims,
   characterized
   in that the coupling (17) has, on each of the two parts (13; 14) of the follower (7), a carrier (20) and also a coupling element (21) which can be adjusted in relation to the carriers (20) and, in the coupled-in state, couples the two carriers (20) to one another in a rotationally fixed manner and then moves at the same time in the event of rotation of the follower (7).
5. Door lock according to Claim 4, characterized in that the adjustable coupling element (21) is mounted radially outside the carriers (20) on a coupling slide (22) such that it can be adjusted in the form of an arc of a circle in a limited manner, the coupling slide (22) is mounted such that it can be radially adjusted in relation to the carriers (20), and the coupling (17) can be operated by adjusting the coupling slide (20).
6. Door lock according to either of Claims 4 and 5,
   characterized
   in that the electrical actuating drive (19), together with the adjustable coupling element (21) and possibly also with the coupling slide (22), is arranged in a common installation part (23) in the lock case (1).
7. Door lock according to one of the preceding claims,
   characterized
   in that the coupling (17) inherently stably maintains at least the coupled-in state.
8. Door lock according to one of the preceding claims,
   characterized
   in that a dedicated handle spindle (15; 16) is in engagement or can be brought into engagement in a torque-transmitting manner with each of the two parts (13; 14) of the follower (7),
   wherein the two handle spindles (15; 16) are arranged and oriented coaxially in relation to one another, wherein, preferably, the two handle spindles (15; 16) are connected to one another fixedly in the direction of their common longitudinal axis but in a freely rotatable manner in relation to one another about the longitudinal axis, and/or
   wherein, preferably, the two handle spindles (15; 16) are axially fixed to the follower (7).
9. Door lock according to one of the preceding claims,
   characterized
   in that an electrical locking drive (25) is provided for adjusting the locking element (5),
   in that the electrical locking drive (25), by way of a one-sided freewheel, acts on the locking element (5) in such a way that the locking element (5) can always be moved from the electrical locking drive (25) to the unlocking position without impediment,
   wherein, preferably, the electrical locking drive (25) is embodied as a gear/toothed rack drive with an extendable toothed rack (28).
10. Door lock according to Claim 9, characterized in that the electrical locking drive (25) is arranged on the lock case (1) and is connected in a force-transmitting manner to the locking element (5) in only one adjusting direction, or
    in that the electrical locking drive (25) is arranged on the locking element (5) and can be adjusted with the said locking element and is connected in a force-transmitting manner to the lock case (1) in only one adjusting direction.
11. Door lock according to one of the preceding claims,
    characterized
    in that the locking element (5) is spring-prestressed into the locking position.
12. Door lock according to one of the preceding claims,
    characterized
    in that the lock case (1) has a case height of from 120 to 200 mm, preferably of from 150 to 160 mm, and/or a case width of from 60 to 100 mm, preferably of from 80 to 90 mm, and/or a case depth of 10 to 30 mm, preferably of from 12 to 20 mm, in particular of from 13 to 15 mm.

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