EP2662514A2 - Safety mechanism for locks - Google Patents

Abstract

The device has a handle (1) coupled with a locking lug (7) of a locking device in an actuation state. A braking or blocking device i.e. eddy current brake, brakes or blocks rotating movement starting from a defined number of revolutions of the handle in a unit of time. The braking or blocking device comprises a displaceable element that is displaceable between release- and braking or blocking positions and co-operates with a counter-element to brake or block the rotating movement of the handle. The handle is mechanically decoupled from the displaceable element in the release position. The device comprises an eddy current element i.e. eddy current disk, that is made of ferromagnetic material.

Description

The invention relates to a safety device for locks with a handle which is freely rotatable in the idle state and in the operating state with the locking member of the lock, wherein a braking or blocking device is provided, the more from a defined number of revolutions of the handle in a time unit Rotary movement brakes or blocks, wherein the braking or blocking device comprises a displaceable between a release position and a braking or blocking position element which cooperates in the braking or blocking position with a counter-element to brake or block the further rotational movement.

Conventional locks can be operated by means of a key, by turning a key in a lock a corresponding locking lug is rotated, which moves a bolt in a closed position or retracts from a closed position to an open position. In electronic security systems, a recognition logic and an electronic key in the form of cards or other identification media replace the key. After reading the electronic key, which corresponds to the mechanical scanning of a conventional key, the rotational movement of a handle, such as a knob or handle via a corresponding coupling with another rotatably mounted part rotatably coupled, which actuates the latch in the sequence. In this context, electronic security systems have become known, which are designed as a double-knob cylinder, wherein on one side of the door to be opened elements of a detection logic, and in particular antennas or the like., Are arranged, whereas the coupling of the rotational movement of this outer rotatable part after detecting the correct key via an electronics mostly on electrical Path is made by engaging a coupling element. In such devices, the external handle is freely rotatable without such a coupling. This freely rotatable handle is connected via a shaft with the opposite side of the door or the window on which the coupling is made with the actuator of the lock. The shaft is thereby passed through the castle with relatively little play, the free rotation at the same time relatively little play without the risk of jamming and without the risk of unintentional coupling must be guaranteed. A possible training is for example the DE 19851308 A1 can be seen in which the lock cylinder is provided on both sides with Drehknäufen, of which the inside door knob has access control electronics. Depending on the identification of an identification medium, an access authorization is determined, wherein a clutch is actuated electromagnetically in such a way that a locking bit can be moved from the outside door-side rotary knob.

Due to the low tolerances in the production of such safety devices but has now been shown that a possible improper manipulation is created by the fact that a corresponding drive unit, such as an electric motor or spring mechanism motor is connected to the freely rotatable handle, which quickly in the handle Rotation offset. In such a rapid rotation, a corresponding frictional heat is generated in the interior of the lock, which can lead to rubbing or unintentional coupling of an outer shaft with an inner shaft upon expansion of the usual manner freely spinning shaft, so that in this way, despite the lack of electronic release of the clutch a mechanical coupling achieved by thermal expansion or trituration between the usually freely rotatable handle and the pawl arises, whereby the lock can be operated. However, such incorrect operation or sabotage operation requires that the freely rotatable handle can be brought over a minimum time to a corresponding minimum speed, which can lead to thermal expansion or trituration.

To exclude such a sabotage or incorrect operation and at the same time to ensure that the freely rotatable handle remains freely rotatable only with a relatively low rotational speed and counteracts rubbing or jamming in other cases, is in the WO 2007/095652 A1 already a safety device of the type mentioned above has been proposed in which at least one radially guided displaceable centrifugal weight is coupled to the handle, which engages from a defined number of revolutions of the handle in a time unit with a stationary part of the lock and blocks the further rotational movement , The centrifugal lock ensures that if the speed of the freely rotatable handle is too high, a blockage occurs immediately.

In a safety device in the WO 2007/095652 A1 However, the correct operation, especially in those cases can not be guaranteed with certainty in which a particularly high torque is applied to the handle. In this case, there is the danger that the elements displaceable due to the centrifugal force are mechanically overloaded and subsequently destroyed.

The invention therefore aims to improve a safety device of the type mentioned in that the functionality even at very high rotational speeds and high torque applied to the handle be guaranteed. The safety device should function largely independently of the external forces acting on the lock forces.

To solve this problem, the invention provides according to a first aspect in a safety device of the type mentioned above, that the handle is mechanically decoupled from the displaceable element in its release position. The mechanical decoupling ensures that forces acting from outside on the handle and the shaft possibly connected with the handle can not be transmitted to the part responsible for the application of the braking torque or the blocking, namely to the displaceable element of the braking or blocking device , Manipulation or damage due to violence is thus excluded. The displaceable element is therefore structurally separated in particular in the release position of the handle or a rotatably connected to the handle element and in particular does not rotate with the handle. According to a preferred development, the displaceable element cooperates only in the braking or blocking position with the handle or with a rotatably coupled to the handle part to brake or block the further rotational movement.

The invention includes embodiments in which the detection device for detecting the rotational speed of the handle is different from the braking or blocking device, in particular is mechanically decoupled. Thus, unlike the centrifugal brake described in the prior art, the braking or blocking device is not subject to the geometrical and material limitations of the torque detecting device and therefore can be stably constructed.

The mechanical decoupling of the rotational movement of the handle from the displaceable element is preferably achieved in that a drive for displacing the displaceable element between the release position and the braking or blocking position is provided by the non-contact, in particular magnetic coupling with the rotational movement of the handle in motion is displaceable. The non-contact coupling is preferably formed by a driven by the rotational movement of the handle eddy current coupling.

Alternatively, the non-contact coupling may comprise an electrical generator which is driven by the rotational movement of the handle and which provides an electrical voltage for driving the displaceable element.

Particularly preferably, the eddy current coupling is designed in the manner of an eddy current tachometer. The eddy current coupling in this case preferably comprises an eddy current element and a permanent magnet element, which are rotatable relative to each other. In an eddy current tachometer, the permanent magnet element provided with a permanent magnet rotates and generates eddy currents in the eddy current element mounted at a distance therefrom. The eddy current element preferably consists of a metal disc or bell made of an electrically conductive material, in particular aluminum. Due to the eddy currents in the eddy current element creates an additional field energy. This field energy would be avoided if the rotatably mounted eddy current element would rotate with it. But it is prevented by a reset element. The magnetic field increases linearly with the speed, the field energy quadratic, the force acting as their derivative linear again, as well as the restoring force of the return element with its angular deflection. This is the deflection or the angle of rotation of the eddy current element proportional to the speed. The return element may in this case preferably be designed as a spring element. Alternatively, any other element suitable for receiving a torque or a force may be used as the return element. For example, the repulsion of two identically polarized magnets could be used as resistance to the angular deflection.

In the embodiment of the eddy current tachometer described above, the permanent magnet element is coupled to the rotational movement of the handle and thus driven by this. Alternatively, however, the eddy current tachometer can also be designed so that the eddy current element is coupled to the rotational movement of the handle. In this case, not the eddy current element, but the rotatably mounted permanent magnet element is connected to the return element.

The angular deflection of the part of the eddy current tachometer connected to the return element is preferably translated via a transmission or a conversion unit into a displacement movement of the displaceable element, so that the displaceable element is displaced from the release position and the braking or blocking position. Preferably, the training is in this case made such that the transmission or the conversion unit can move the displaceable element regardless of the direction of rotation of the handle from the release position to the braking or blocking position.

The gear or the conversion element comprises, for example, a ramp formed on the part of the eddy current tachometer connected to the return element, which converts the angular deflection of this part into an axial and / or radial movement of the displaceable element. The displaceable element may in this case be guided in the axial and / or radial direction and axially and / or radially engage with a rotatably connected to the handle part of the lock into engagement and thereby block the further rotational movement of the handle.

A preferred embodiment provides that the eddy current element is formed as an eddy current disc made of ferromagnetic material. In some circumstances, the use of a ferromagnetic material can lead to an amplification of the eddy currents.

In an eddy current coupling or an eddy current tachometer usually at least one permanent magnet is arranged on the permanent magnet element so that both the one pole and the other pole of the magnet faces the eddy current element. However, a preferred embodiment provides, as an alternative, for the permanent magnet element to have a first pole and a second pole, wherein the first pole faces the eddy current element and the second pole is remote from the eddy current element. In such an embodiment, a magnetic circuit may close across the eddy current element. This is favored in accordance with a preferred embodiment by the fact that the eddy current coupling has a metallic, preferably ferromagnetic housing, which forms a closed magnetic circuit with the first and the second pole of the permanent magnet element.

The risk of sabotage or incorrect operation described above exists in particular in locks in which the handle is rotatably connected to a lock passing through the coupling shaft, which is coupled via a coupling with an actuating shaft which is rotatably connected to the locking member of the castle, said Actuating shaft as a hollow shaft is formed, which is penetrated by the coupling shaft.

The object underlying the invention is achieved according to a further aspect of the invention by a safety device for locks, which has a handle which is freely rotatable in the idle state and in the operating state with the locking member of the lock, wherein a braking or blocking device is provided from a defined number of revolutions of the handle in a unit of time the further rotational movement brakes or blocks, wherein the braking or blocking device is designed as an eddy current brake. The eddy current brake in this case has in particular a magnetic element and an eddy current element, wherein the magnetic element either has at least one permanent magnet or an electromagnet, which is turned on when a certain speed of the handle is exceeded, whereby the eddy current brake applies a torque of the handle opposite torque.

The invention will be explained in more detail with reference to embodiments shown schematically in the drawing. In this show Fig. 1 a schematic overall view of a locking device according to the invention in teilzerlegtem state with safety device, Fig. 2 an enlarged view of the safety device in a first embodiment, Fig. 3 a detailed view of the eddy current element of the first embodiment, Fig. 4a and Fig. 4b Views on two variants of the permanent magnet element of the first embodiment and Fig. 5 an enlarged view of the safety device in a second embodiment.

In Fig. 1 is denoted by 1 a knob, which is freely rotatably connected via a hollow shaft 2 and a coupling shaft 3 with a housed in another knob 4 electromechanical clutch disc. The clutch disc itself may be formed in any desired manner and, for example, magnetically or mechanically coupled with a corresponding component, such as the knob 4. The actuating shaft is denoted by 5 and is penetrated by a sliding sleeve 6. Furthermore, a locking lug 7 is provided for the operation of the lock bolt, said locking lug 7 is held in the axial direction adjusted by corresponding snap rings 8 and rotatably connected to the actuating shaft 5, which in turn rotatably with the inside knob 4 or after the coupling rotatably connected to the clutch shaft 3 is connected.

Without a corresponding coupling of the actuating shaft 5 with the knob 1, the hollow shaft 2 and the coupling shaft 3 connected thereto can be freely rotated. The coupling shaft extends through the sliding sleeve 6 and rotates inside the same. In a sabotage, in which the knob 1 and thus the coupling shaft 3 is acted upon by a high torque and rotated in rotation with rotational speeds of 5,000 - 20,000 rev / min, it can cause thermal expansion and triturations, so that the sliding sleeve 6 suddenly with the Coupling shaft 3 co-rotated. As a result, due to the same effect, the actuating shaft 5 can be taken away from the sliding sleeve 6, which can lead to an undesired actuation of the locking lug 7.

In order to avoid the unwanted actuation of the locking lug 7 described above, a safety device is arranged in the knob 4, which is coupled to the rotational movement of the coupling shaft 3 is and their further rotational movement from a defined rotational speed brakes or blocks. The safety device comprises in the in Fig. 2 illustrated first embodiment, a disk designed as a permanent magnet element 9, which is rotatably connected to the clutch shaft 3. The permanent magnet element 9 has at least one permanent magnet and cooperates with an eddy current element 10, which is cup-shaped and surrounds the disc-shaped permanent magnet element 9 circumferentially. The permanent magnet element 9 and the eddy current element 10 together form an eddy current tachometer, wherein, as in Fig. 3 can be seen, the eddy current element 10 is connected to a formed as a spring 11 retaining element which exerts a restoring moment on the eddy current element 10, as soon as it starts from the in Fig. 3 shown rest position experiences an angular deflection. In this way, the angular deflection of the eddy current element 10 is directly proportional to the rotational speed of the permanent magnet element 9. The angular deflection of the eddy current element 10 is now translated via a suitable transmission in a sliding movement of a displaceable element, not shown, so that the displaceable element from a release position in a brake or Blocking position is shifted. In the braking or blocking position, the displaceable element engages in a recess of the coupling shaft 3 or cooperates in another way with the coupling shaft 3 or a rotatably connected thereto component to exert a braking torque or a blocking effect on the coupling shaft 3 and the knob 1 ,

Fig. 4a shows a view of the end face of the permanent magnet element 9, the permanent magnet having a first magnetic pole (north pole) 15 and a second magnetic pole (south pole) 16, both of which the eddy current element 10 faces. In the Training according to Fig. 4b the eddy current element 10 facing end face is divided into four, with two south poles 16 and two north poles 15 are provided, which are arranged alternately in the circumferential direction. Other modifications are conceivable in which the end face is divided into 6, 8, 10, etc. parts.

In Fig. 5 a modified embodiment of the safety device is shown, in which the eddy current tachometer is enclosed by a ferromagnetic housing 12. The eddy current element 10 is likewise formed from a ferromagnetic material. Furthermore, a permanent magnet is arranged on the permanent magnet element 9 such that one magnetic pole 13 of the permanent magnet faces the eddy current element 10 and the other magnetic pole 14 of the permanent magnet faces away from the eddy current element 10. This closes on the housing 12, a magnetic circuit.

In principle, the invention is not limited to specific embodiments of locking devices. Thus, the safety device according to the invention can be used not only in cylinder locks, but for example in fittings, which have the function to couple the handle with the door latch operation or decouple. In the decoupled state, the handle, such as e.g. a pusher without effect, while the handle in the coupled state actuates the case. In the decoupled state, the safety device according to the invention is used and is intended to prevent a jerky actuation of the handle without access authorization to an actuation of the trap.

Claims (12)

Safety device for locks with a handle which is freely rotatable in the idle state and in the operating state with the locking member of the lock, wherein a braking or blocking device is provided which brakes or blocks the further rotational movement in a unit of time from a defined number of revolutions of the handle wherein the braking or blocking device comprises a displaceable between a release position and a braking or blocking position element which cooperates in the braking or blocking position with a counter-element to brake or block the further rotational movement, characterized in that the handle ( 1) is mechanically decoupled from the displaceable element in its release position. Safety device according to claim 1, characterized in that the displaceable element in the braking or blocking position with the handle (1) or with the handle (1) rotatably coupled part (3) cooperates to brake or block the further rotational movement. Safety device according to claim 1 or 2, characterized in that a drive for displacing the displaceable element between the release position and the braking or blocking position is provided, which is displaceable by non-contact, in particular magnetic coupling with the rotational movement of the handle in motion. Safety device according to claim 3, characterized in that the non-contact coupling of one of the rotational movement of the handle (1) driven eddy current coupling is formed. Safety device according to claim 4, characterized in that the eddy current coupling is designed in the manner of an eddy current tachometer. Safety device according to claim 4 or 5, characterized in that the eddy current coupling comprises an eddy current element (10) and a permanent magnet element (9) which are rotatable relative to each other. Safety device according to claim 6, characterized in that the eddy current element (10) is designed as an eddy current disc made of ferromagnetic material. Safety device according to claim 6 or 7, characterized in that the permanent magnet element (9) has a first magnetic pole (13) and a second magnetic pole (14), the first magnetic pole (13) facing the eddy current element (10) and the second magnetic pole ( 14) facing away from the eddy current element (10). Safety device according to claim 8, characterized in that the eddy current coupling has a metallic, preferably ferromagnetic housing (12) which forms a closed magnetic circuit with the first and the second magnetic pole (13, 14) of the permanent magnet element (9). Safety device for locks with a handle which is freely rotatable in the idle state and in the operating state with the locking member of the lock, wherein a braking or blocking device is provided which brakes or blocks the further rotational movement in a unit of time from a defined number of revolutions of the handle . characterized in that the braking or blocking device is designed as an eddy current brake. Safety device according to one of claims 1 to 10, characterized in that the handle (1) rotatably connected to a lock passing through the coupling shaft (3) is coupled via a coupling with an actuating shaft (5) rotatably connected to the locking member (5). 7) of the lock is connected, wherein the actuating shaft (5) is designed as a hollow shaft which is penetrated by the coupling shaft (3). Locking device for building doors, preferably lock cylinder or fitting, window or the like. With a handle which is freely rotatable in the idle state and in the operating state with the locking member of the locking device, characterized by a safety device according to one of claims 1 to 11.

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