Magnetic lock for a control unit in an elevator installation

A control unit for an elevator installation comprises a cover and a base. The control unit further comprises a lock which can lock the cover to the base or release it from the base. The lock comprises a locking bar with a magnet, wherein this locking bar is movable back and forth between a closed position and an open position by movement of a magnetic lock on a surface of the cover. The locking bar with the magnet is stabilized in the closed position by a first magnetic element and the cover is locked. The locking bar with the magnet is stabilized in the open position by a second magnetic element and the cover is released.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to European Patent Application No. 10171892.2, filed Aug. 4, 2010, which is incorporated herein by reference.

FIELD

The present disclosure relates to a lock for a control unit in an elevator installation.

BACKGROUND

Control units are usually mounted in elevator cages and/or in front of shaft doors in elevator installations. Such control units serve for, for example, the input of a destination story by the passenger and for the indication of items of information, such as, for example, a designation of a story at which the elevator cage is currently located. In that case, the control units are usually connected with switching and safety circuits of the elevator installation by cable connections. At the time of service operations at the elevator installation it can be necessary to open a control unit in order to gain access to the interior of the control unit.

Generally, such control units are merely hooked in place or screw-connected. Control units which are hooked in place are often readily accessible to persons not intended to have access. Screw-connected control units generally are awkward to open.

However, in order to provide protection against vandalism, such control units are sometimes locked. Simple locks such as, for example, triangular locks sometimes do not offer effective protection against vandalism. Other locks are sometimes expensive on the one hand, and on the other hand are similarly exposed to vandalism. Thus, for example, the keyhole can be locked or damaged.

SUMMARY

At least some embodiments of the disclosed technologies provide a control unit with a lock which can be securely locked and can be opened in simple manner and which is convenient to produce. In at least some cases, the lock is simple to integrate into an overall design of the control unit.

Some embodiments comprise a control unit with a magnetic lock. The control unit for an elevator installation comprises a cover and a base. The control unit further comprises a lock which can lock the cover to the base or release it from the base. The lock comprises a locking bar with a magnet, wherein this locking bar is movable back and forth from a closed position to an open position by movement of a magnetic key on a surface of the cover. In that case the locking bar with the magnet is stabilized in the closed position by a first magnetic element and the cover is locked. In the open position the locking bar is stabilized by a second magnetic element and the cover is released.

A control unit with such a magnetic lock can have the advantage that the lock is not visible externally and is therefore not at risk of vandalism. Nevertheless, such a lock is capable of securely locking a control unit. Moreover, it can be economic in production, since neither lock cylinders nor keys matching therewith have to be made. In addition, it is advantageous that such a lock can be accommodated in simple mode and manner in a design of a control unit. Thus, such a magnetic lock can, for example, be located under a company logo or at a place on the control unit without text.

The control unit comprises a cover and a base. In that case the base is fastened to a component of the elevator installation such as, for example, a cage inner wall or a shaft door post. The cover is, for example, rotatably connected with the base by way of a hinge. However, in an alternative embodiment the cover can also be completely separate from the base. The cover can consist merely of the cover surface of the control unit or, however, also include buttons or displays and/or electronic components. Equally, the base can consist only of a frame or, however, comprise buttons or displays and/or electronic components. It will be clear to the expert that the distribution of the individual components of a control unit on the cover or to the base can be undertaken in various ways.

The control unit can on the one hand, be control units for passengers such as used, for example, in elevator cages or on stories. On the other hand, control units are also used for the control of elevator installations by maintenance personnel. Such control units are located, for example, on roofs of elevator cages or in engine rooms. Moreover, the control unit can also be control units for the fire service or other bodies with special access authorization. Consequently, a control unit with such a magnetic lock can be used with versatility, wherein the above list is not exhaustive.

In an exemplary embodiment the locking bar is guided in the base in such a manner that it is secured at least in the open position and in the closed position against falling out of the base. For this purpose the locking bar can have, for example, a trapezoid-shaped cross-section along a movement direction of the locking bar, wherein a shorter base side of the trapezoid is closer to the cover than a longer base side of the trapezoid. In that case, the base of the control unit engages around the longer base side of the trapezoid and at least in part the lateral sides of the trapezoid.

In further embodiments the locking bar is guided along a movement direction, wherein a movement of the locking bar is limited by abutments to a region between the open and closed positions.

In a further embodiment a marking is arranged on a surface of the cover and indicates to a user in which regions of the surface the magnetic key can open and close the lock.

DETAILED DESCRIPTION

An elevator cage is shown in three-dimensional illustration inFIG. 1. The elevator cage has side walls2, a ceiling4and a floor3. A cage door5is arranged in a side wall2. If the elevator cage is located at a story, passengers can disembark from the cage via a shaft opening6when the cage door5is open. A shaft door (not illustrated), which can be moved synchronously with the cage door5, is usually arranged on each story.

A cage control unit1is fastened to a side wall2. The cage control unit1can in principle be fastened to any side wall2. The cage control unit1is connected with switching and safety circuits (not illustrated) of the elevator installation.

The cage control unit1comprises a display7and buttons8. The display7is suitable for the purpose of illustrating items of information for the passenger such as, for example, a designation of a story at which the elevator cage is currently located. The buttons8serve for, for example, the input of a destination story by the passenger or for triggering an emergency call in an emergency situation. A story control unit10is arranged in the shaft opening6. The story control unit10similarly has a button18and displays17. The button18is suitable for the purpose of calling an elevator cage. The displays17serve the purpose of indicating to a waiting passenger in which direction the arriving elevator cage is traveling.

In at least some cases, for maintenance and service operations it can be necessary to open the cage control unit1and/or the story control unit10in order to gain access to internal components. In this exemplifying embodiment the cage control unit1has hinges9arranged laterally thereof so that the cage control unit1can be opened without having to be separated from the cage side wall2. Analogously thereto, the story control unit10has laterally arranged hinges19so that the story control unit10can be opened without having to be separated from the inner wall of the shaft opening6.

No magnetic lock is visible inFIG. 1, because it is located under a cover of the cage control unit1or the story control unit10. In the following figures the magnetic lock is explained in more detail by way of exemplifying forms of embodiment.

An exemplifying form of embodiment of a magnetic lock is shown in sectional illustration inFIGS. 2 to 4. InFIG. 2this magnetic lock is in a closed position. InFIG. 3this magnetic lock is in an open position and inFIG. 4this magnetic lock is similarly in an open position, wherein the cover, by contrast toFIG. 3, is open.

The control unit illustrated inFIGS. 2 to 4comprises a base22and a cover21. The base22is in that case connected by a hinge29with the cover21. In these illustrations neither displays nor buttons are depicted. A first magnetic element23and a second magnetic element24are arranged in the base22. A locking bar26with a magnet27is arranged to be displaceable by way of these magnetic elements23,24with respect to the base22. InFIG. 2this locking bar26is so positioned that the magnet27is closer to the first magnetic element23than to the second magnetic element24, wherein the locking bar26is stabilized in this position by the first magnetic element23. In this position the magnetic lock is closed. InFIG. 3the magnet27of the locking bar26is disposed closer to the second magnetic element24than to the first magnetic element23, wherein the locking bar26is stabilized in this position by the second magnetic element24. The magnetic lock is open in this position.

A hand of a user38positions a magnetic key25on a surface32of the cover21. If the magnetic key25is positioned as inFIG. 2the locking bar26is brought into the closed position because the magnet27is magnetically attracted by the magnetic key25. If, however, the magnetic key25is positioned as illustrated inFIG. 3, then the locking bar26is disposed in the open position, because the magnet27is magnetically attracted by the magnetic key25. The locking bar26is stabilized not only in the open position, but also in the closed position, because the respective magnetic element23,24disposed closer to the magnet27exerts a stronger influence on the magnet27and thus on the locking bar26by virtue of a smaller spacing than the respective other magnetic element23,24.

In order to fix the cover21to the base22in a closed position, the locking bar26has a projection31which can engage in a hook28of the cover21. InFIG. 2this projection31prevents the cover from being able to be opened and inFIG. 3the cover21is released by the projection31.

The magnetic elements23,24can, for example, consist of iron or material with iron content. In an alternative form of embodiment the magnetic elements23,24are formed as permanent magnets. The magnetic key25possibly comprises a permanent magnet. Alternatively thereto the magnetic key25can also comprise electromagnets which are activatable, for example, by a button.

With respect to the construction of the magnetic elements23,24it is, however, to be noted that the magnetic force of the magnetic key25should generally be of sufficient magnitude to move the lock from one position to the other position. In that case the magnetic forces or the spacings between the magnetic key25, the magnet27and the magnetic elements23,24can be so selected that the locking bar26is switched over by mere positioning of the magnetic key on the surface32of the cover21. Alternatively thereto the magnetic forces can also be selected so that a displacement of the magnetic key25on the surface32of the cover21is necessary in order to switch over the locking bar26.

It is evident that the design of the magnetic components23,24,25,27can be carried out in numerous ways in order to ensure the characteristics described here. The forms of embodiment expressed here are therefore to be understood merely as examples deriving from a multiplicity of possible alternatives.

An alternative form of embodiment of a control unit20is illustrated inFIG. 5. A cover21is again rotatably connected with a base22by way of a hinge29. By contrast to the exemplifying embodiment illustrated inFIGS. 2 to 4, in this exemplifying embodiment the locking bar26has engagement elements which can respectively engage in a first groove39and a second groove37. In the illustrated closed position the engagement elements are disposed in the respective first grooves39. If the locking bar26is now moved by a magnetic key into the open position then the engagement elements36are respectively disposed in the second30grooves37. Thanks to the engagement elements the locking bar26is protected not only in the closed position, but also in the open position from falling out of the base22.

An alternative mechanism for securing the locking bar26against falling out of the base22is illustrated inFIG. 6. In this cross-sectional illustration a movement direction of the locking bar26is located perpendicularly to the illustration surface. The locking bar26has in this exemplifying embodiment a trapezoid-shaped cross-section. In that case the shorter base side of the trapezoid is closer to the cover21than the longer base side of the trapezoid. By virtue of the inclined lateral sides of the trapezoid, which are retained by a corresponding recess in the base22, the locking bar26is protected against dropping out of the base22when the cover21is open.

Two exemplifying embodiments of a detail of a control unit20are illustrated in plan view inFIGS. 7 and 8. In that case only the cover21is visible in each instance. The hinge29is illustrated by a dotted line. A movement space of the locking bar in the base is similarly illustrated by a dotted line. Respective markings33,35are applied to the cover21. These show to a user how the magnetic key can be held or placed on the cover21in order to open and close the lock.

InFIG. 7these markings33,35consist of two circles, wherein placed near a first circle is the designation ‘close’ and near a second circle the designation ‘open’. If the magnetic key is now held on one of these markings33,35in circular form, then the lock opens or closes. The circular form can correspond with a plan area of the magnetic key. It will be obvious that other forms such as rectangles, triangles or irregular shapes can also be used instead of circles.

InFIG. 8the marking consists of two arrows33,35and respectively associated designations ‘open’ and ‘close’. If the magnetic key is now moved in arrow direction over the markings33,35then the magnetic lock opens and closes.

Having illustrated and described the principles of the disclosed technologies, it will be apparent to those skilled in the art that the disclosed embodiments can be modified in arrangement and detail without departing from such principles. In view of the many possible embodiments to which the principles of the disclosed technologies can be applied, it should be recognized that the illustrated embodiments are only examples of the technologies and should not be taken as limiting the scope of the invention. Rather, the scope of the invention is defined by the following claims and their equivalents. I therefore claim as my invention all that comes within the scope and spirit of these claims.