SE544599C2 - Actuator and lock device - Google Patents

Abstract

An actuator (ioa-iod) comprising a primary core member (12) having a first and second primary section (44, 46) and a primary coil section (48), the primary core member being arranged to adopt a first and second primary polarity; a primary electric coil (30) wound around the primary coil section and arranged to provide the first and/or second primary polarity in the primary core member; a secondary core member (14) having a first and second secondary section (50, 52), the secondary core member being arranged to adopt a first and second secondary polarity; and a movable member (16) comprising at least one magnet (20, 84, 86) and being movable between a first position (18), in which the at least one magnet is magnetically forced towards the first primary section and towards the first secondary section, and a second position (40), in which the at least one magnet is magnetically forced towards the second primary section and towards the second secondary section.

Description

ACTUATOR AND LOCK DEVICE Technical Field The present disclosure generally relates to an actuator. In particular, an actuator, and a lock device comprising such actuator, are provided.Background Various types of actuators may be used in lock devices. Some lock devices usea linear solenoid actuator for effecting locking and unlocking of the lockdevice. The solenoid actuator may for example comprise a ferromagneticactuator pin, an electric coil wound around the actuator pin, and a springforcing the actuator pin into a locked position. In the locked position, noelectric current may be supplied to the electric coil. By passing an electriccurrent through the electric coil, the electric coil produces a magnetic fieldforcing the actuator pin to move against the force of the spring from thelocked position and into an unlocked position. Some solenoid actuators ofthis type can be manipulated. By subjecting the solenoid actuator tovibrations or bumping, the actuator pin can be caused to impermissibly move from the locked position to the unlocked position.

In order to improve the security, the actuator may comprise an electric motorinstead of the linear solenoid. The electric motor may rotationally drive a leadnut that in turn threadingly engages a lead screw to cause the lead screw totranslate linearly. Although such electric motors can better withstandvibrations, such electric motors are typically not designed to only switchbetween two distinct positions. For example, an output member of suchelectric motor (such as a lead screw) in a lock device can often be controlledto be positioned in one or more intermediate position between a lockedposition and an unlocked position. Since such intermediate positions areoften not used in a lock device, the rating of the electric motor is unnecessarily high. That is, the design of such electric motors for lock devices 1O is often quite exclusive in order to merely accomplish a locked position andan unlocked position. This leads to added cost and power consumption.

Moreover, such electric motors are difficult to produce in a very small size.Summary One object of the present disclosure is to provide an actuator having a high security.

A further object of the present disclosure is to provide an actuator having a small size.

A still further object of the present disclosure is to provide an actuator having a compact design.

A still further object of the present disclosure is to provide an actuator having a low power consumption.

A still further object of the present disclosure is to provide an actuator having a cost effective design.

A still further object of the present disclosure is to provide an actuator having a less complicated design.

A still further object of the present disclosure is to provide an actuator solving several or all of the foregoing objects in combination.

In particular, a still further object of the present disclosure is to provide anactuator having a high security, a small size, a low power consumption and a cost effective design.

A still further object of the present disclosure is to provide a lock devicecomprising an actuator, which lock device solves one, several or all of the foregoing objects.

According to one aspect, there is provided an actuator comprising a primary core member of magnetically conductive material, the primary core member 1O having a first primary section, a second primary section and a primary coilsection between the first primary section and the second primary section, theprimary core member being arranged to adopt a first primary polarity and asecond primary polarity; a primary electric coil wound around the primarycoil section and arranged to provide the first primary polarity and/ or thesecond primary polarity in the primary core member; a secondary coremember of magnetically conductive material, the secondary core memberhaving a first secondary section and a second secondary section, thesecondary core member being arranged to adopt a first secondary polarityand a second secondary polarity; and a movable member comprising at leastone magnet, the movable member being movable between a first position, inwhich the at least one magnet is magnetically forced towards the first primarysection by means of the first primary polarity and towards the first secondarysection by means of the first secondary polarity, and a second position, inwhich the at least one magnet is magnetically forced towards the secondprimary section by means of the second primary polarity and towards the second secondary section by means of the second secondary polarity.

In case the actuator is subjected to a strong external magnetic field in anattempt to tamper with the actuator, each of the primary core member, thesecondary core member and the at least one magnet of the movable memberwill respond to this external magnetic field. Since the actuator is designedsuch that the movable member adopts the first position when primary coremember adopts the first primary polarity and the secondary core memberadopts the first secondary polarity, the external magnetic field needs toswitch the polarity of each of the primary core member and the secondarycore member in order to cause the movable member to move from the firstposition to the second position, at the same time as the external magneticfield does not counteract movement of the movable member from the firstposition to the second position by interaction with the at least one magnet.The actuator therefore provides a very high security against tampering bysubjecting the actuator to a strong external magnetic field with a design of low complexity. The low complexity design in turn enables a cheap 1O manufacture, the size of the actuator to be reduced and the power consumption to be reduced.

Moreover, since the principle of operation of the actuator enables animproved resistance against tampering by subjecting the actuator to a strongexternal magnetic field, the actuator does not need to comprise a casing forshielding from external magnetic fields. As a consequence, the size of the actuator can be further reduced.

Since the magnet is magnetically forced towards the primary core memberand the secondary core member in each of the first position and the secondposition, the movable member can be held in each of the first position andthe second position by means of a magnetic force of the at least one magnetand without any power supply. The at least one magnet generates a magneticfield. The movable member may be held stationary in each of the first position and the second position only by means of this magnetic field.

The actuator provides two distinct positions of the movable member, namelythe first position and the second position. Each of the first position and thesecond position constitutes an end position of the movable member. Thus,the actuator may be configured such that the movable member moves fromthe first position to the second position in a second direction and such thatthe movable member is prevented from moving from the first position to thesecond position in a first direction, opposite to the second direction.Conversely, the actuator may be configured such that the movable membermoves from the second position to the first position in the first direction andsuch that the movable member is prevented from moving from the second position to the first position in the second direction.

The actuator may be an actuator for locking and unlocking a lock device. Inthis case, the first position and the second position may be a locked positionand an unlocked position, respectively, for the lock device, or vice versa.Thus, in contrast to many prior art electric motors for lock devices that are designed to position an output shaft at one or more intermediate positions 1O between a first position and a second position, the actuator according to thepresent disclosure is optimized to only position the movable member ineither of two distinct positions (the first position and the second position).The actuator does therefore not need to comprise features dedicated toposition the movable member in any intermediate position between the firstposition and the second position. The actuator is therefore optimized interms of size, power consumption, security and production cost. The actuatoraccording to the present disclosure can be used in applications other than lock devices.

The primary core member and the secondary core member may be arrangedin parallel. With this is meant that the actuator can still function to move themovable member from the first position to the second position with only onecore member. However, with only one core member, the movable memberwill be possible to impermissibly manipulate by subjecting the actuator to a strong external magnetic field.

The first primary section may comprise a first primary surface, the secondprimary section may comprise a second primary surface, the first secondarysection may comprise a first secondary surface and the second secondarysection may comprise a second secondary surface. Each of the first primarysurface, the second primary surface, the first secondary surface and thesecond secondary surface may be substantially parallel, or parallel. In thiscase, each of the first primary surface, the second primary surface, the firstsecondary surface and the second secondary surface may lie substantially in,or lie in, a common plane. Alternatively, the first primary surface and thesecond primary surface may lie in a primary plane, and the first secondarysurface and the second secondary surface may lie in a secondary plane, offset from the primary plane.

Each of the first primary section, the second primary section, the firstsecondary section and the second secondary section may be an arm. In thiscase, the first primary section and the second primary section may be substantially parallel, or parallel, and the first secondary section and the 1O second secondary section may be substantially parallel, or parallel. Accordingto one example, all of the first primary section, the second primary section,the first secondary section and the second secondary section are arms arranged substantially in parallel, or in parallel.

Each of the primary core member and the secondary core member may begenerally U-shaped, U-shaped, generally arc-shaped or arc-shaped. The firstprimary section and the second primary section may extend substantially perpendicularly, or perpendicularly, to the primary coil section.

Each of the primary core member and the secondary core member may forexample be made of ferromagnetic material, such as alnico (an alloy which inaddition to iron is composed primary of aluminium, nickel and cobalt), ironor steel containing less than 3 % carbon by weight. Each magnet may be apermanent magnet. Each magnet may for example comprise a Neodymiumalloy such as a Neodymium-Iron-Boron (NdFeB), or other alloy having arelatively high intrinsic remanence. A relatively high intrinsic coercivity maybe used to further protect each magnet from being demagnetized by an applied external magnetic field.

The movable member may comprise a transfer element. The transfer elementmay be configured to engage an engageable structure in the first position, andconfigured to be disengaged from the engageable structure in the secondposition. When the movable member adopts the first position, the transferelement may be in a protruded position. When the movable member adoptsthe second position, the transfer element may be in a retracted position. Thetransfer element may be a rigid piece, such as a pin. The engageable structure may be an engageable structure of the lock device.

The transfer element may be a blocking element. In this case, the actuatorfunctions as a blocking device. The transfer element may block movement ofan output member, e.g. of the lock device, in the first position, and unblock movement of the output member in the second position. In this case, the first 1O position and the second position of the transfer element constitute a locked state and an unlocked state, respectively, of the actuator.

Alternatively, the transfer element may be a coupling element. In this case,the actuator functions as a clutch. The transfer element may decouple aninput member of the lock device from an output member of the lock devicewhen adopting the second position. Thus, when the transfer element adoptsthe second position, movements of the input member are not transmitted bythe transfer element to movements of the output member. The transferelement may further couple the input member to the output member whenadopting the first position. Movement and torque from the input member canthen be transferred to the output member by means of the transfer elementheld in the first position. In this case, the first position and the secondposition of the transfer element constitute an unlocked state and a locked state, respectively, of the actuator.

The secondary core member may comprise a secondary coil section betweenthe first secondary section and the second secondary section. In this case, theactuator may further comprise a secondary electric coil wound around thesecondary coil section and arranged to provide the first secondary polarityand/ or the second secondary polarity in the secondary core member. Thefirst secondary section and the second secondary section may extend substantially perpendicular, or perpendicular, to the secondary coil section.

Each of the primary coil section and the secondary coil section may bepositioned on one side of the movable member. Alternatively, the movablemember may be positioned between the primary coil section and thesecondary coil section. According to a further variant, the actuator comprises four core members, each having a coil section and an associated electric coil.

The primary electric coil and the primary coil section form a primaryelectromagnet. The secondary electric coil and the secondary coil section form a secondary electromagnet. 1O By applying an electric current through the primary electric coil and thesecondary electric coil in a first direction, a first north pole and a first southpole appear in each of the primary core member and the secondary coremember. The magnetic fields produced by the current through the primaryelectric coil and the secondary electric coil in the first direction, and themagnetic field generated by the at least one magnet cause the movablemember to flip from the second position to the first position. For example, arepulsive magnetic force between the first south pole of the primary coremember and the south pole of the at least one magnet, and a repulsivemagnetic force between the first north pole of the secondary core memberand the north pole of the at least one magnet, may cause the movable member to flip from the second position to the first position.

By applying a current through the primary electric coil and the secondaryelectric coil in a second direction, opposite to the first direction, a secondnorth pole and a second south pole appear in each of the primary coremember and the secondary core member. The magnetic fields produced bythe current through the primary electric coil and the secondary electric coil inthe second direction, and the magnetic field generated by the at least onemagnet cause the movable member to flip from the first position back to thesecond position. For example, a repulsive magnetic force between the secondsouth pole of the primary core member and the south pole of the at least onemagnet, and a repulsive magnetic force between the second north pole of thesecondary core member and the north pole of the at least one magnet, maycause the movable member to flip from the first position to the second position.

Thus, a quick electric pulse in the primary electric coil and in the secondaryelectric coil forces the movable member to move from the second position tothe first position, and a reversed pulse causes the movable member to movefrom the first position to the second position. By pulsing the primary electriccoil and the secondary electric coil with the appropriate electrical polarity, the at least one magnet will align itself with the magnetic field, also moving 1O the movable member. The arrangement thereby operates with very low power consumption and has a cost effective, compact and less complicated design.

According to one variant, each of the primary core member and thesecondary core member may be an electropermanent magnet comprising asection of hard magnetic material (of high coercivity) and a section of softmagnetic material (of low coercivity). The primary core member can therebybe switched on to produce an external magnetic field, and be switched offsuch that no net external magnetic field is produced across its poles, bymeans of an electric pulse through the primary electric coil. The on state andthe off state of the primary core member may correspond to the first primarypolarity and the second primary polarity, respectively, of the primary coremember. Correspondingly, the secondary core member can be switched on toproduce an external magnetic field, and be switched off such that no netexternal magnetic field is produced across its poles, by means of an electricpulse through the secondary electric coil. The off state and the on state of thesecondary core member may correspond to the first secondary polarity andthe second secondary polarity, respectively, of the secondary core member.By utilizing electropermanent magnets in this way, the movable member canmagnetically held in the first position and in the second position with a high force or a high torque.

The primary coil section and the secondary coil section may be substantially parallel, or parallel.

The first primary polarity may be substantially opposite to, or opposite to, thefirst secondary polarity. In this case, it will not be possible to switch themovable member between the first position and the second position by subjecting the actuator to an external magnetic field.

A first primary magnetic flow in the primary core member may besubstantially opposite to, or opposite to, a first secondary magnetic flow inthe secondary core member when the movable member adopts the first position. Correspondingly, a second primary magnetic flow in the primary 1O core member may be substantially opposite to, or opposite to, a secondsecondary magnetic flow in the secondary core member when the movable member adopts the second position.

The at least one magnet may be arranged to establish a magnetic pathbetween the primary core member and the secondary core member in each ofthe first position and the second position. For example, the at least onemagnet may be in contact with each of the first primary section and the firstsecondary section in the first position, and in contact with each of the second primary section and the second secondary section in the second position.

The movable member may comprise a conductive element of magneticallyconductive material. In this case, the conductive element may be arranged toestablish a magnetic path between the primary core member and thesecondary core member in each of the first position and the second position.For example, the magnetically conductive element may be in contact witheach of the second primary section and the second secondary section in thefirst position, and in contact with each of the first primary section and thefirst secondary section in the second position. The conductive element maybe of the same material as the first core member and the second core member.

The actuator may thus be configured to establish a closed magnetic circuit,e.g. with very small air gaps, in each of the first position and the secondposition of the movable member. This further contributes to enabling a smallsize of the actuator. In the first position, the at least one magnet may providea closed magnetic path between the first primary section and the firstsecondary section, and the conductive element may provide a closedmagnetic path between the second primary section and the second secondarysection. In the second position, the at least one magnet may provide a closedmagnetic path between the second primary section and the second secondarysection, and the conductive element may provide a closed magnetic pathbetween the first primary section and the first secondary section. As an alternative to the conductive element, a further magnet may be used. 1OThe movable member may comprise an actuating member. The actuatingmember may be arranged between the at least one magnet and theconductive element. The actuating member may be a rod. The transferelement may be fixed to the rod, e.g. extending substantially perpendicularly to, or perpendicularly to, the rod.

The at least one magnet may be in contact with the first primary section andthe first secondary section in the first position. The at least one magnet maybe in contact with the second primary section and the second secondarysection in the second position. In this case, the at least one magnet may bemagnetically forced against the first primary section and against the firstsecondary section in the first position, and magnetically forced against thesecond primary section and against the second secondary section in the second position.

In the first position, a north pole of the at least one magnet may be in contactwith the first secondary section and a south pole of the at least one magnetmay be in contact with the first primary section. In the second position, thenorth pole may be in contact with the second secondary section and the south pole may be in contact with the second primary section.

The movable member may be rotatable about a rotation axis between the firstposition and the second position. A rotatable movable member furtherincreases resistance against tampering, both by subjecting the actuator to a strong external magnetic field and by vibrations.

In this case, a first rotational position and a second rotational position of themovable member constitute the first position and the second position,respectively. The movable member may for example be rotatable 45 degreesto 180 degrees, such as 90 degrees or 180 degrees, about the rotation axis between the first position and the second position.

The primary core member and the secondary core member may be separated along the rotation axis. In this way, it can be avoided that magnetic field 1Opasses over an air gap between the primary core member and the secondary core member.

The rotation axis may be substantially centered, or centered, between the firstprimary section and the second primary section, and between the first secondary section and the second secondary section.

As an alternative, the movable member may be linearly movable between the first position and the second position.

The at least one magnet may have a sector-shaped or arc-shaped cross-section. An angular distance of the sector shape or the arc shape may forexample be 85 degrees to 95 degrees, such as 90 degrees, with respect to therotation axis. Alternatively, or in addition, the at least one magnet may have acircular outer profile. The circular outer profile may be concentric with the rotation axis. Each magnet may for example be cylindrical.

The actuator may further comprise a control system, the control systemcomprising at least one data processing device and at least one memoryhaving a computer program stored thereon, the computer programcomprising program code which, when executed by the at least one dataprocessing device, causes the at least one data processing device to performthe steps of evaluating an authorization request; and commanding sending ofa current pulse through the primary electric coil in response to a grantedevaluation of the authorization request. Alternatively, or in addition, thecomputer program may comprise program code which, when executed by theat least one data processing device, causes the at least one data processingdevice to perform the steps of receiving a switching command; andcommanding sending of a current pulse through the primary electric coil inresponse to receiving the switching command. The computer program mayfurther comprise program code which, when executed by the at least one dataprocessing device, causes the at least one data processing device to perform, or command performance of, various steps as described herein. 1OThe control system may be configured to apply a current pulse in a firstdirection to each of the primary electric coil and the secondary electric coil togenerate the magnetic field for moving the movable member from the secondposition to the first position, and to apply a current pulse in a seconddirection, opposite to the first direction, to each of the primary electric coiland the secondary electric coil to generate the magnetic field for moving themovable member from the first position back to the second position. Thecontrol system may further comprise a receiving unit, such as an antenna, forreceiving the authorization request. The control system may be configured todetermine whether or not authorization should be granted based on theauthorization request. If access is granted, e.g. if a valid credential ispresented, a current pulse is sent through each of the primary electric coil and the secondary electric coil.

According to a further aspect, there is provided a lock device comprising anactuator according to the present disclosure. The lock device may comprisean input member and an output member. The lock device may further comprise a stationary structure, such as a housing.

In case the transfer element is a blocking element, the transfer element mayprevent the input member and/ or the output member from being movedwhen the transfer element adopts the first position, and the transfer elementmay allow the output member to be moved by movement of the inputmember when the transfer element adopts the second position. In case thetransfer element is a coupling element, the transfer element may prevent theoutput member from being moved by movement of the input member whenthe transfer element adopts the second position, and the transfer elementmay allow the output member to be moved by movement of the input member when the transfer element adopts the first position.

The lock device may further comprise an engageable structure for beingengaged by the transfer element in the first position. The engageablestructure may be an aperture. The engageable structure may be arranged in the input member, in the output member or in the stationary structure. The 1Oinput member may be rotatable or linearly movable. The output member may be rotatable or linearly movable.

In case the lock device is a lock cylinder, the lock cylinder may comprise astationary structure having an engageable structure and a cylinder corerotatably accommodated in the stationary structure. When the transferelement adopts the second position, the cylinder core is allowed to rotaterelative to the stationary structure. When the transfer element adopts thefirst position, the transfer element engages the engageable structure such thatthe cylinder core is prevented from rotating relative to the stationary structure.

The lock device may be an energy harvesting lock device. To this end, the lockdevice may further comprise an electric generator arranged to generateelectric energy from movement of the input member. In this case, the lockdevice may be arranged to power the control system by means of harvestedelectric energy. The energy harvesting lock device may not comprise a battery.

The lock device may for example be a lock cylinder, a lock case, a pad lock, akeypad locker lock, a strike assembly, or a handle device for operating doors, windows and the like. Other implementations are conceivable.

According to a further aspect, there is provided a method of controlling a lockdevice, the method comprising providing a lock device according to thepresent disclosure; evaluating an authorization request; and sending acurrent pulse through the primary electric coil in response to a grantedevaluation of the authorization request. The lock device for the method may be of any type according to the present disclosure.Brief Description of the Drawings Further details, advantages and aspects of the present disclosure will becomeapparent from the following description taken in conjunction with the drawings, wherein: 1O Fig.

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Fig. !13: 14: : schematically represents a plane view of an actuator when amovable member is in a first position; schematically represents a plane view of the actuator when themovable member is in a second position; schematically represents a partial perspective view of the actuatorwhen the movable member is in the first position; schematically represents a further partial perspective view of theactuator when the movable member is in the first position;schematically represents a further partial perspective view of theactuator when the movable member is in the first position;schematically represents a further partial perspective view of theactuator; schematically represents a partial perspective view of the actuatorwhen the movable member is in the second position;schematically represents a further partial perspective view of theactuator when the movable member is in the second position;schematically represents a side view of a lock device comprisingthe actuator when the movable member is in the first position;schematically represents a side view of the lock device when themovable member is in the second position and when an inputmember is manually actuated; schematically represents a front view of a further lock devicecomprising the actuator when the movable member is in the firstposition; schematically represents a front view of the lock device in Fig. 11when the movable member is in the first position and when aninput member is manually actuated; schematically represents a perspective view of a further actuatorwhen a movable member is in the first position; schematically represents a perspective view of the actuator in Fig.13 when the movable member is in the second position;schematically represents a cross-sectional side view of a further example of an actuator; 1OFig. 16 schematically represents a plane view of a further example of anactuator when the movable member is in the first position; Fig. 17a: schematically represents a cross-sectional view of section A-A inFig. 16; Fig. 17b: schematically represents a cross-sectional view of section B-B inFig. 16; Fig. 17c: schematically represents a cross-sectional view of section C-C inFig. 16; Fig. 18: schematically represents a plane view of the actuator in Fig. 16when the movable member is in the second position; Fig. 19a: schematically represents a cross-sectional view of section D-D inFig. 18; Fig. 19b: schematically represents a cross-sectional view of section E-E inFig. 18; and Fig. 19c: schematically represents a cross-sectional view of section F-F inFig.Detailed Description In the following, an actuator, and a lock device comprising such actuator, willbe described. The same or similar reference numerals will be used to denote the same or similar structural features.

Fig. 1 schematically represents a plane view of an actuator 1oa. The actuator1oa comprises a primary core member 12 and a secondary core member 14.Each of of the primary core member 12 and the secondary core member 14 is made of a magnetically conductive material, such as iron.

The actuator 1oa further comprises a movable member 16. The movablemember 16 is movable relative to the primary core member 12 and thesecondary core member 14 between a first position 18 and a second position.

In Fig. 1, the movable member 16 is in the first positionThe movable member 16 of this example comprises a single permanent magnet 20. The movable member 16 further comprises a rod 22, here of 1Ocylindrical shape. The rod 22 is one example of an actuating member according to the present disclosure. The magnet 20 is fixed on the rodThe movable member 16 of this example further comprises a transfer element24. The transfer element 24 is here exemplified as a rigid pin fixed to, and extending perpendicularly from, the rodThe movable member 16 of this example further comprises two non-conductive elements 26 (only one can be seen in Fig. 1). Each non-conductiveelement 26 is fixed on the rod 22. Each non-conductive element 26 may for example be made of aluminium.

In this example, the movable member 16 is rotatable about a rotation axis 28between the first position 18 and the second position. The rod 22 is concentric with the rotation axisThe actuator 1oa of this example further comprises a primary electric coil 30and a secondary electric coil 32. The primary electric coil 30 is wound aroundthe primary core member 12. The secondary electric coil 32 is wound around the secondary core memberThe actuator 1oa of this example further comprises a control system 34. Thecontrol system 34 comprises a data processing device 36 and a memory 38.The memory 38 has a computer program stored thereon. The computerprogram comprises program code which, when executed by the dataprocessing device 36, causes the data processing device 36 to perform, orcommand performance of, various steps as described herein. The controlsystem 34 is configured to apply current pulses to each of the primary electriccoil 30 and the secondary electric coil 32 such that magnetic fields aregenerated (or such that soft magnets in the core members 12 and 14 areflipped) . To this end, the control system 34 may comprise a power controller(not shown), e.g. having switches, a pulse control transistor and a flybackdiode for protecting the pulse control transistor. The power controller may beconnected to a charged capacitor optimized for the specific current pulses. A short current pulse through each of the primary electric coil 30 and the 1Osecondary electric coil 32 causes the magnet 20 to flip such that the movable member 16 moves from the first position 18 to the second position.

Fig. 2 schematically represents a plane view of the actuator 10a when themovable member 16 is in the second position 40. In the second position 40,the movable member 16 has rotated 90 degrees about the rotation axis 28.The transfer element 24 has thereby adopted a different position (pointing down into the paper in Fig. 2).

Fig. 2 also shows that the movable member 16 of this example further comprises a conductive element 42. Also the conductive element 42 is madeof a magnetically conductive material, such as iron. The conductive element42 is fixed on the rod 22. The magnet 20 and the conductive element 42 are here arranged on opposite sides of the rodFig. 3 schematically represents a partial perspective view of the actuator 10a,and Fig. 4 schematically represents a further partial perspective view of theactuator 10a. With collective reference to Figs. 3 and 4, the movable member16 is in the first position 18. As shown, the actuator 10a has a very compact and simple design.

The primary core member 12 is U-shaped. The primary core member 12comprises a first primary section 44, a second primary section 46, and aprimary coil section 48 between the first primary section 44 and the secondprimary section 46. The primary electric coil 30 is wound around the primarycoil section 48. Each of the first primary section 44 and the second primarysection 46 is here an arm extending at right angles from the primary coil sectionThe secondary core member 14 has a design corresponding to the primarycore member 12. Thus, the secondary core member 14 is U-shaped. Thesecondary core member 14 comprises a first secondary section 50, a secondsecondary section 52, and a secondary coil section 54 between the firstsecondary section 50 and the second secondary section 52. The secondary electric coil 32 is wound around the secondary coil section 54. Each of the 1Ofirst secondary section 50 and the second secondary section 52 is here an arm extending at right angle from the secondary coil sectionIn this example, each of the first primary section 44, the second primarysection 46, the first secondary section 50 and the second secondary section52 comprises a contact surface in a common plane. Moreover, the primarycore member 12 and the secondary core member 14 are separated from each other along the rotation axisThe number of windings of the primary electric coil 30 and the secondaryelectric coil 32 may vary. Each of the primary electric coil 30 and the secondary electric coil 32 may comprise copper wirings.

The primary core member 12 and the secondary core member 14 are arrangedside by side and with a corresponding position and orientation relative to therotation axis 28. The primary core member 12 and the secondary coremember 14 are thus arranged on the same side of the movable member 16 inthis example. The primary core member 12 and the secondary core member 14 are offset along the rotation axisAs shown in Figs. 3 and 4, the magnet 20 of this example has a sector-shapedcross-section with an angular distance of 90 degrees with respect to therotation axis 28. In the first position 18 of the movable member 16, a southpole "S" of the magnet 20 is in contact with the first primary section 44 and anorth pole "N" of the magnet 20 is in contact with the first secondary section50. No power supply is required to hold the magnet 20 in the first positionEach of the two non-conductive elements 26 also has a sector-shaped cross-section with an angular distance of 90 degrees with respect to the rotationaxis 28. Each non-conductive elements 26 is here of the same length alongthe rotation axis 28 as the magnet 20. Each non-conductive element 26 ispositioned between the magnet 20 and the conductive element 42, but on opposite sides of the rod1O Fig. 5 schematically represents a further partial perspective view of theactuator 10a when the movable member 16 is in the first position 18. In Fig. , it can be seen that also the conductive element 42 has a sector-shapedcross-section with an angular distance of 90 degrees with respect to therotation axis 28. A length of the conductive element 42 along the rotation axis 28 is however somewhat shorter than the magnetFig. 6 schematically represents a further partial perspective view of theactuator 10a. As shown in Fig. 6, each of the first primary section 44, thesecond primary section 46, the first secondary section 50 and the secondsecondary section 52 comprises a curved profile corresponding to the exterior shape of the conductive element 42 and the non-conductive elementsWith collective reference to Figs. 1 and 3-6, the magnet 20 is magneticallyforced to the first position 18 by means of a first primary polarity in theprimary core member 12 and by means of a first secondary polarity in thesecondary core member 14. A closed magnetic circuit is provided in theactuator 10a that passes from the magnet 20, through the first secondarysection 50, through the secondary coil section 54, through the secondsecondary section 52, through the conductive element 42, through the secondprimary section 46, through the primary coil section 48, through the firstprimary section 44 and back to the magnet 20. In this example, nosubstantial air gaps are provided in the magnetic circuit when the movablemember 16 adopts the first position 18. As can be gathered, the magnetic fieldis oriented upwardly in the primary coil section 48 and downwardly in thesecondary coil section 54. The design of the actuator 10a therefore makes itimpossible to switch the movable member 16 from the first position 18 to thesecond position 40 by subjecting the actuator 10a to a strong external magnetic field.

Fig. 7 schematically represents a partial perspective view of the actuator 10a,and Fig. 8 schematically represents a further partial perspective view of theactuator 10a. In Figs. 7 and 8, the movable member 16 is in the second position 40. In order to move the movable member 16 from the first position 1O18 to the second position 40, an electric pulse is supplied by the controlsystem 34 to the primary electric coil 30 in a second direction such that thefirst primary polarity in the primary core member 12 is switched to anopposite second primary polarity, and an electric pulse is supplied by thecontrol system 34 to the secondary electric coil 32 in a second direction suchthat the first secondary polarity in the secondary core member 14 is switchedto an opposite second secondary polarity. This causes a south pole to beprovided in each of the first primary section 44 and in the "diagonallyopposite" second secondary section 52, and a north pole to be provided ineach of the second primary section 46 and in the "diagonally opposite" firstsecondary section 50. The south pole of the magnet 20 is thereby repelled bythe south pole at the first primary section 44, and attracted to the north poleat the second primary section 46. The north pole of the magnet 20 is therebyrepelled by the north pole at the first secondary section 50, and attracted tothe south pole at the second secondary section 52. This causes the movablemember 16 to move from the first position 18 to the second position 40. Inthis example, the movable member 16 rotates 90 degrees about the rotationaxis 28, from a position where the magnet 20 is in contact with the firstprimary section 44 and the first secondary section 50, to a position where themagnet 20 is in contact with the second primary section 46 and the second secondary sectionNo power supply is required to hold the magnet 20 in the second positionIn the second position 40, a closed magnetic circuit is provided in theactuator 10a that passes from the magnet 20, through the second secondarysection 52, through the secondary coil section 54, through the first secondarysection 50, through the conductive element 42, through the first primarysection 44, through the primary coil section 48, through the second primarysection 46 and back to the magnet 20. Also in the second position 40, nosubstantial air gaps are provided in the magnetic circuit in this example. Ascan be gathered, the magnetic field is now oriented downwardly in theprimary coil section 48 and upwardly in the secondary coil section 54. In order to switch the movable member 16 from the second position 40 back to 1Othe first position 18, the control system 34 supplies an electric pulse to eachof the primary electric coil 30 and the secondary electric coil 32 in a first direction, opposite to the second direction.

Fig. 9 schematically represents a side view of a lock device 56a comprising the actuator 10a. The movable member 16 is here in the first positionThe lock device 56a of this example comprises a handle 58a and a latch bolt60a. The handle 58a is one example of an input member and the latch bolt60a is one example of an output member according to the present disclosure.In this specific example, the handle 58a is arranged to rotate and the latch bolt 60a is arranged to move linearly.

The lock device 56a further comprises a transmission 72. The transmission 72is configured to transmit a movement of the handle 58a to a movement of thelatch bolt 60a. To this end, the transmission 72 may for example comprise gear wheels and/ or a linkage.

The latch bolt 60a comprises an aperture 74. The aperture 74 is one exampleof an engageable structure according to the present disclosure. In the first position 18, the transfer element 24 engages the aperture 74. The lock device56a is thereby in a locked state 76. The transfer element 24 here functions as a blocking element.

Fig. 10 schematically represents a side view of the lock device 56a. A validcredential has been presented and the control system 34 has thereby sent acurrent pulse in the second direction through each of the primary electric coil30 and the secondary electric coil 32 to flip the movable member 16 from thefirst position 18 to the second position 40, and to cause the transfer element24 to move out from the aperture 74. The lock device 56a is thereby in an unlocked stateThe handle 58a is now manually rotated to retract the latch bolt 60a as shown by arrow 80 to open the lock device 56a. The transfer element 24 thus 1Ounblocks movement of the latch bolt 60a when the movable memberadopts the second positionFig. 11 schematically represents a front view of a further lock device 56bcomprising the actuator 1oa. The movable member 16 is in the first position 18. The transfer element 24 here functions as a coupling element.

The lock device 56b comprises a knob 58b and a locking member 6ob. Theknob 58b is a further example of an input member and the locking member6ob is a further example of an output member according to the presentdisclosure. In this specific example, the knob 58b and the locking member6ob are arranged to rotate about a common rotation axis. It should beemphasized that the lock device 56b in Fig. 11 is merely schematicallyillustrated. In particular, the actuator 1oa may be arranged partly inside the knob 58b or partly inside the locking member 6ob.

In Fig. 11, the locking member 6ob comprises the aperture 74. In the firstposition 18 of the movable member 16, the transfer element 24 is seated inthe aperture 74. A valid credential has been presented and the control system34 has thereby commanded to send a current pulse in the first directionthrough each of the primary electric coil 30 and the secondary electric coil 32to cause the movable member 16 to move from the second position 40 to thefirst position 18. The lock device 56b is thereby in an unlocked state 78. In theunlocked state 78, the transfer element 24 couples the knob 58b to the locking member 60b.

Fig. 12 schematically represents a front view of the lock device 56b in Fig. 11.When the movable member 16 is in the first position 18 such that the transferelement 24 engages the aperture 74, a manual rotation of the knob 58b istransmitted by the transfer element 24 to a rotation 82 of the lockingmember 6ob. The knob 58b and the locking member 6ob can thereby be rotated in common to unlock the lock device 56b.

In case the movable member 16 remains in the second position 40, a rotation of the knob 58b will not be transmitted to a rotation of the locking member 1O6ob. The lock device 56b will then be in a locked state. The actuator 1oa thereby functions as a clutch in this example.

Fig. 13 schematically represents a perspective view of a further actuator 1ob.Mainly differences with respect to Figs. 1 to 12 will be described. In theactuator 1ob, the primary core member 12 and the secondary core member 14are arranged on opposite sides of the movable member 16. The movablemember 16 of this example comprises a rod 22, a primary magnet 84 fixed tothe rod 22 and a secondary magnet 86 fixed to the rod 22. The secondarymagnet 86 is distanced from the primary magnet 84 along the rotation axis28. Moreover, the primary magnet 84 and the secondary magnet 86 are positioned on opposite sides of the rodIn the first position 18 of the movable member 16, a magnetic field generatedby the primary magnet 84 passes through the first primary section 44,through the primary coil section 48, through the second primary section 46and then over an air gap back to the primary magnet 84. A magnetic fieldgenerated by the secondary magnet 86 passes over an air gap to the secondsecondary section 52, through the second secondary section 52, through thesecondary coil section 54, through the first secondary section 50 and back tothe secondary magnet 86. In the first position 18, the primary core member12 adopts a first primary polarity and the secondary core member 14 adopts afirst secondary polarity. Also in Fig. 13, the primary core member 12 and thesecondary core member 14 are separated from each other along the rotation axisFig. 14 schematically represents a perspective view of the actuator 1ob in Fig.13. In order to move the movable member 16 from the first position 18 to thesecond position 40, a current pulse in a second direction is passed througheach of the primary electric coil 30 and the secondary electric coil 32. As aconsequence, the primary core member 12 is switched from the first primarypolarity to the second primary polarity and the secondary core member 14 isswitched from the first secondary polarity to the second secondary polarity. A north pole is thereby generated in the first primary section 44 causing the 1O primary magnet 84 to be repelled, and a south pole is thereby generated inthe first secondary section 50 causing the secondary magnet 86 to berepelled. The movable member 16 thereby rotates to the second position 40where the south pole of the primary magnet 84 is attracted to the north polein the second primary section 46, and where the north pole of the secondary magnet 86 is attracted to the south pole in the second secondary sectionFig. 15 schematically represents a cross-sectional side view of a furtherexample of an actuator 10c. Mainly differences with respect to the actuator10a will be described. The magnet 20 of the actuator 10c is arc-shaped, in contrast to the sector-shaped magnet 20 of the actuator 10a.

Instead of the conductive element 42, the actuator 10c comprises a furthermagnet 88. The magnet 88 of this example is of the same shape as theconductive element 42. The magnets 20 and 88 are arranged on oppositesides of the non-conductive element 26. The magnet 88 is orientedmagnetically opposite to the magnet 20. Thus, in the illustrated first position18 of the movable member 16, the magnet 88 is magnetically forced towardsthe second primary section 46 by means of the first primary polarity andtowards the second secondary section 52 (not shown by means of the firstsecondary polarity. As shown in Fig. 15, the magnets 20 and 88 have thesame cross-sectional area. The flux densities in the magnets 20 and 88 are thereby balanced.

Fig. 16 schematically represents a plane view of a further example of anactuator 10d, Fig. 17a schematically represents a cross-sectional view ofsection A-A in Fig. 16, Fig. 17b schematically represents a cross-sectional viewof section B-B in Fig, and Fig. 17c schematically represents a cross-sectionalview of section C-C in Fig. 16. Mainly differences with respect to the actuator10a will be described. In Figs. 16, 17a, 17b and 17c, the movable member 16 isin the first position 18. As shown in Fig. 16, the actuator 10a comprises twoprimary core members 12 and two secondary core members 14. Each of theprimary core members 12 and the secondary core members 14 is arc-shaped, here having an angular extension of approximately 170 degrees with respect 1Oto the rotation axis 28. The two primary core members 12 are aligned alongthe rotation axis 28 and mirrored in a plane comprising the rotation axis 28.The two secondary core members 14 are offset from the two primary coremembers 12 along the rotation axis 28, aligned along the rotation axis 28 and mirrored in the plane comprising the rotation axisThe actuator 1od comprises a primary magnet 84 and a secondary magnet86. The primary magnet 84 is associated with the two primary core members12 and the secondary magnet 86 is associated with the two secondary coremembers 14. Each of the primary magnet 84 and the secondary magnet 86 isa cylinder in this example. Each of the primary magnet 84 and the secondarymagnet 86 is divided in half into two segments constituting respective southpoles and north poles. The combination of arc-shaped core members 12 and14 and cylindrical magnets 84 and 86 enable the actuator 1od to be made very small.

Figs. 17a, 17b and 17c show the magnetic fields in the primary core members12 and the secondary core members 14, respectively, when the movable member 16 is in the first positionFig. 18 schematically represents a plane view of the actuator 1od in Fig. 16when the movable member 16 is in the second position 40, Fig. 19aschematically represents a cross-sectional view of section D-D in Fig. 18, Fig. 19b schematically represents a cross-sectional view of section E-E in Fig.18, and Fig. 19c schematically represents a cross-sectional view of section F-Fin Fig. 18. As shown, the movable member 16 of this example rotates 18odegrees about the rotation axis 28 between the first position 18 and the second position 4o.

While the present disclosure has been described with reference to exemplaryembodiments, it will be appreciated that the present invention is not limitedto what has been described above. For example, it will be appreciated that the dimensions of the parts may be varied as needed. Accordingly, it is intendedthat the present invention may be limited only by the scope of the claims appended hereto.

Claims (1)

1. An actuator (10a-10d) comprising: - a primary core member (12) of magnetically conductive material, theprimary core member (12) having a first primary section (44), a secondprimary section (46) and a primary coil section (48) between the firstprimary section (44) and the second primary section (46), the primarycore member (12) being arranged to adopt a first primary polarity and asecond primary polarity; - a primary electric coil (30) wound around the primary coil section (48)and arranged to provide the first primary polarity and/ or the secondprimary polarity in the primary core member (12); - a secondary core member (14) of magnetically conductive material, thesecondary core member (14) having a first secondary section (50) and asecond secondary section (52), the secondary core member (14) beingarranged to adopt a first secondary polarity and a second secondarypolarity; and - a movable member (16) comprising at least one magnet (20, 84, 86),the movable member (16) being movable between a first position (18),in which the at least one magnet (20, 84, 86) is magnetically forcedtowards the first primary section (44) by means of the first primarypolarity and towards the first secondary section (50) by means of thefirst secondary polarity, and a second position (40), in which the at leastone magnet (20, 84, 86) is magnetically forced towards the secondprimary section (46) by means of the second primary polarity andtowards the second secondary section (52) by means of the second secondary polarity. The actuator (10a-10d) according to claim 1, wherein the movablemember (16) comprises a transfer element (24) configured to engage anengageable structure (74) in the first position (18), and configured to be disengaged from the engageable structure (74) in the second position (40)- 1OThe actuator (1oa-1od) according to any of the preceding claims,wherein the secondary core member (14) comprises a secondary coilsection (54) between the first secondary section (50) and the secondsecondary section (52), and wherein the actuator (1oa-1od) furthercomprises a secondary electric coil (32) wound around the secondarycoil section (54) and arranged to provide the first secondary polarity and/ or the second secondary polarity in the secondary core member (14)- The actuator (1oa-1od) according to claim 3, wherein the primary coilsection (48) and the secondary coil section (54) are substantially parallel. The actuator (1oa-1od) according to any of the preceding claims,wherein the first primary polarity is substantially opposite to the first secondary polarity. The actuator (1oa-1od) according to any of the preceding claims,wherein a first primary magnetic flow in the primary core member (12)is substantially opposite to a first secondary magnetic flow in thesecondary core member (14) when the movable member (16) adopts the first position (18). The actuator (1oa-1od) according to any of the preceding claims,wherein the at least one magnet (20, 84, 86) is arranged to establish amagnetic path between the primary core member (12) and thesecondary core member (14) in each of the first position (18) and the second position (4o). The actuator (1oa-1od) according to any of the preceding claims,wherein the movable member (16) comprises a conductive element (42)of magnetically conductive material, and wherein the conductiveelement (42) is arranged to establish a magnetic path between theprimary core member (12) and the secondary core member (14) in each of the first position (18) and the second position (4o). 1OThe actuator (10a-10d) according to any of the preceding claims,wherein the movable member (16) comprises an actuating member(22), and wherein the actuating member (22) is arranged between the at least one magnet (20, 84, 86) and the conductive element (42). The actuator (10a-10d) according to any of the preceding claims,wherein the at least one magnet (20, 84, 86) is in contact with the firstprimary section (44) and the first secondary section (50) in the firstposition (18), and is in contact with the second primary section (46) and the second secondary section (52) in the second position (40). The actuator (10a-10d) according to any of the preceding claims,wherein the movable member (16) is rotatable about a rotation axis (28) between the first position (18) and the second position (40). The actuator (10a-10d) according to claim 11, wherein the rotation axis(28) is substantially centered between the first primary section (44) andthe second primary section (46), and between the first secondary section (50) and the second secondary section (52). The actuator (10a-10d) according to any of the preceding claims,wherein the at least one magnet (20, 84, 86) has a sector-shaped or arc- shaped cross-section. The actuator (10a-10d) according to any of the preceding claims, furthercomprising a control system (34), the control system (34) comprising atleast one data processing device (36) and at least one memory (38)having a computer program stored thereon, the computer programcomprising program code which, when executed by the at least one dataprocessing device (36), causes the at least one data processing device(36) to perform the steps of: - evaluating an authorization request; and - commanding sending of a current pulse through the primary electriccoil (30) in response to a granted evaluation of the authorization request.15. A lock device (56a, 56b) comprising an actuator (10a-10d) according to any of the preceding claims.