Patent Grant
11454049
This application is a national stage application under 35 U.S.C. 371 and claims the benefit of PCT Application No. PCT/EP2018/083591 having an international filing date of Dec. 5, 2018, which designated the United States, which PCT application claimed the benefit of Sweden Patent Application No. 1751574-3 filed Dec. 19, 2017, the disclosure of each of which are incorporated herein by reference.
The present disclosure generally relates to actuators comprising an electro permanent magnet. In particular, an actuator comprising an electro permanent magnet and a movable member arranged to move between a first position and a second position, lock devices comprising the actuator, a handle device comprising the actuator and a method for operating the actuator, are provided.
Various types of actuators may be used in lock devices. One type of powered actuator is a motor that rotates a drive shaft, which requires power to both lock and unlock a lock device, for example an electric strike. Another type of powered actuator is a solenoid which has a plunger that moves relative to a housing in response to power being supplied. Such solenoids are typically provided with a spring to return the plunger to its original position without power. The solenoid includes a coil and a shaft which is axially movable within the coil. The coil is energized by connection to a source of electrical current and thereby generates magnetic flux which influences the shaft to move in one direction. When the coil is de-energized, the spring operates to move the shaft in the reverse direction. One advantage with solenoids over motors is that in a power failure event, the plunger can still return to its original position.
US 2012299315 A1 discloses a structure for electrical locks comprising two rotational members, a latching assembly and a controlling means. The two rotational members are respectively secured to two handles of a door. The latching assembly includes a cartridge, a sliding element and a dividing rod. The dividing rod is fitted in the cartridge to define two lateral zones respectively corresponding to two recesses of the rotational members. The sliding member is slidably fitted in one of the lateral zones of the cartridge. The controlling means includes a pushing assembly and a solenoid. When the solenoid is de-energized, the pushing assembly can be moved forward to lock a respective handle. When the solenoid is energized, the pushing assembly can be moved back to free the respective handle.
One object of the present disclosure is to provide an actuator having a low power consumption.
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 reliable operation.
A still further object of the present disclosure is to provide an actuator having a simple design.
A still further object of the present disclosure is to provide an actuator having a good protection against tampering.
A still further object of the present disclosure is to provide an actuator that is efficient, i.e. has a high magnetic holding force relative to its size.
A still further object of the present disclosure is to provide an actuator solving two or more of the foregoing objects.
A still further object of the present disclosure is to provide a lock device comprising an actuator solving one, several or all of the foregoing objects.
A still further object of the present disclosure is to provide a handle device comprising an actuator solving one, several or all of the foregoing objects. A still further object of the present disclosure is to provide a method for operating an actuator solving one, several or all of the foregoing objects.
According to one aspect, there is provided an actuator comprising at least one base section; at least one permanent magnet arranged in the base section; at least one electro permanent magnet arranged in the base section, the at least one electro permanent magnet being configured to switch a polarity between a first polarity and a second polarity when being subjected to a magnetic field and configured to maintain the polarity when the magnetic field is removed; a coil located around the electro permanent magnet; a power controller configured to apply a current pulse to the coil to generate the magnetic field for changing the polarization of the electro permanent magnet; and a movable member comprising at least one magnetic target section, the movable member being arranged to move to a first position relative to the base section, when the electro permanent magnet adopts the first polarity, and arranged to move to a second position relative to the base section due to a magnetic field generated by the permanent magnet and the electro permanent magnet in combination and acting on the magnetic target section, when the electro permanent magnet adopts the second polarity.
When a current pulse of a certain duration and level is applied to the coil wound around the electro permanent magnet, the magnetic field generated by the current pulse flips the polarity of the electro permanent magnet. Once the electro permanent magnet has been flipped from the first polarity to the second polarity, the permanent magnet and the electro permanent magnet combine to generate an electric field. This electric field acts on the magnetic target section of the movable member (e.g. by means of an attractive or repulsive force) such that the movable member moves from the first position to the second position. Once the polarity of the electro permanent magnet has been switched from the first polarity to the second polarity and the movable member has moved from the first position to the second position, the electric field generated by the permanent magnet and the electro permanent magnet in combination may hold the movable member in the second position without power supply. The first position and the second position may constitute distinct positions for the movable member.
Throughout the present disclosure, the base section may be constituted by a stationary structure. According to one variant, the actuator comprises two pole pieces, one permanent magnet and one electro permanent magnet arranged between the two pole pieces. In this case, the base section may be constituted by the permanent magnet, the electro permanent magnet and the two pole pieces. The base section may however comprise further components. The movable member may comprise an elongated portion and a head portion and the magnetic target section may be constituted by, or arranged in, the head portion.
The at least one electro permanent magnet may be hollow, e.g. cylindrical or substantially cylindrical. In this case, the movable member may be arranged to move within the electro permanent magnet. Also the at least one permanent magnet and/or the pole pieces may be hollow. According to one example, the base section comprises an outer cylindrical electro permanent magnet, an inner cylindrical permanent magnet and two circular pole pieces attached to the respective ends of the electro permanent magnet and the permanent magnet. In this case, the coil may be wound around the electro permanent magnet and the movable member may be guided within the electro permanent magnet, the permanent magnet, the pole pieces and the coil. The base section may thus be generally cylindrical and may have an outer diameter of only a few millimeters, such as maximum 5 millimeters.
The actuator according to the present disclosure may be referred to as a low power actuator. The actuator may for example be constituted by an actuator for a lock device, such as a lock cylinder, a lock case or a strike assembly, or for a handle device for operating doors, windows and the like. Other implementations are conceivable.
The electro permanent magnet has lower coercivity than the permanent magnet. Throughout the present disclosure, the electro permanent magnet may alternatively be referred to as a switching magnet or soft magnet and the permanent magnet may alternatively be referred to as a hard magnet. The magnetically hard material may for example comprise a Neodymium alloy such as a Neodymium-Iron-Boron (NdFeB), or other alloy having a relatively high intrinsic coercivity. The magnetically soft material may for example comprise an Alnico alloy, Iron-Cobalt-Vanadium, or other alloy having a relatively low intrinsic coercivity. The permanent magnet and the electro permanent magnet may collectively be referred to as a dual material permanent magnet.
When the electro permanent magnet adopts the second polarity, the movable member may be arranged to move to the second position due to either an attractive magnetic force or a repulsive magnetic force. The actuator may further comprise at least one resetting element configured to move the movable member to the first position when the electro permanent magnet adopts the first polarity. Alternatively, or in addition, the movable member may be forced towards the first position or towards the second position by means of gravity.
The resetting element may be constituted by an elastic element. In this case, the actuator may be configured such that the magnetic field, generated by the permanent magnet and the electro permanent magnet in combination and acting on the magnetic target section when the electro permanent magnet adopts the second polarity, moves the movable member to the second position and deforms the elastic element. The deformation of the elastic element may be either a compression or an extension. For example, the elastic element may be compressed a smaller amount when the movable member adopts the first position and may be compressed a larger amount when the movable member adopts the second position. Alternatively, the elastic element may be extended a smaller amount when the movable member adopts the first position and may be extended a larger amount when the movable member adopts the second position.
The elastic element may be fixed to the base section, or to a section fixed with respect to the base section, and to the movable member, or to a section fixed with respect to the movable member. The elastic element may for example be constituted by a spring, such as a coil spring, or by a rubber component.
According to one variant, the at least one base section is constituted by a first base section and a second base section; the at least one permanent magnet is constituted by a first permanent magnet and a second permanent magnet; and the at least one electro permanent magnet is constituted by a first electro permanent magnet arranged in the first base section and a second electro permanent magnet arranged in the second base section. In this case, the movable member may be arranged to move to the first position relative to the first base section and the second base section, when the first electro permanent magnet adopts the first polarity, and arranged to move to the second position relative to the first base section and the second base section due to a magnetic field generated by the first permanent magnet and the first electro permanent magnet in combination and acting on the magnetic target section, when the first electro permanent magnet adopts the second polarity. The first base section and the second base section may be fixedly connected to each other, for example by means of a connecting member.
The actuator according to this variant may comprise two elastic elements. A first elastic element may be configured to force the movable member to the first position and a second elastic element may be configured to force the movable member to the second position. For example, when the movable member moves to the first position, the first elastic element may be compressed a smaller amount and the second elastic element may be compressed a larger amount and when the movable member moves to the second position, the first elastic element may be compressed a larger amount and the second elastic element may be compressed a smaller amount. A reverse configuration (i.e. by using extension forces of the elastic elements) is also possible. The two elastic elements thus provide a balancing effect on the movable member and thus facilitates the movement of the movable member between the first position and the second position.
The first elastic element may be fixed to the first base section, or to a section fixed with respect to the first base section, and to the movable member, or to a section fixed with respect to the movable member. The second elastic element may be fixed to the second base section, or to a section fixed with respect to the second base section, and to the movable member, or to a section fixed with respect to the movable member. Each elastic element may for example be constituted by a spring, such as a coil spring, or by a rubber component.
According to an alternative example, the actuator according to this variant does not comprise any elastic element for moving the movable member. In this case, the movable member may move from the first position to the second position only due to the magnetic field generated by the first permanent magnet and the first electro permanent magnet in combination with the first electro permanent magnet adopts the second polarity.
Furthermore, in this variant, the second electro permanent magnet may be switched from the second polarity to the first polarity at the same time, or at substantially the same time, as the first electro permanent magnet is switched from the first polarity to the second polarity.
The first base section may for example comprise two first pole pieces and the first permanent magnet and the first electro permanent magnet may be arranged between the two first pole pieces. The second base section may for example comprise two second pole pieces and the second permanent magnet and the second electro permanent magnet may be arranged between the two pole pieces. In this case, the first base section may be constituted by the first permanent magnet, the first electro permanent magnet and the two first pole pieces and the second base section may be constituted by the second permanent magnet, the second electro permanent magnet and the two second pole pieces.
Each of the first electro permanent magnet and the second electro permanent magnet may be hollow, e.g. cylindrical or substantially cylindrical. In this case, the movable member may be arranged to move within each of the first electro permanent magnet and the second electro permanent magnet. Also the first permanent magnet, the second permanent magnet and/or the pole pieces may be hollow. According to one example, each of the first base section and the second base section comprises an outer cylindrical electro permanent magnet, an inner cylindrical permanent magnet and two circular pole pieces attached to the respective ends of the electro permanent magnet and the permanent magnet. In this case, a first coil may be wound around the first electro permanent magnet, a second coil may be wound around the second electro permanent magnet and the movable member may be guided within the first electro permanent magnet, the first permanent magnet, the first pole pieces, the second electro permanent magnet, the second permanent magnet, the second pole pieces, the first coil and the second coil. Each of the first base section and the second base section may thus be generally cylindrical.
The movable member may be arranged to move to the first position relative to the first base section and the second base section due to a magnetic field generated by the second permanent magnet and the second electro permanent magnet in combination and acting on the magnetic target section.
Also in this variant, the actuator may comprise the two elastic elements as described above. Alternatively, the actuator does not need to comprise any elastic element for moving the movable member. In this case, the movable member may move from the second position to the first position only due to the magnetic field generated by the second permanent magnet and the second electro permanent magnet in combination when the second electro permanent magnet adopts the second polarity.
Furthermore, in this variant, the first electro permanent magnet may be switched from the second polarity to the first polarity at the same time, or at substantially the same time, as the second electro permanent magnet is switched from the first polarity to the second polarity.
The actuator may further comprise a first mechanical stop defining the first position of the movable member relative to the base section. The first mechanical stop may for example be constituted by a protrusion, such as a collar, on the elongated portion of the movable member, that engages with the base section. Alternatively, the first mechanical stop may be constituted by a profile, such as an inclined surface, on the head portion of the movable member, that engages with the base section.
The actuator may further comprise a second mechanical stop defining the second position of the movable member relative to the base section. The second mechanical stop may also be constituted by a profile, such as an inclined surface, on the head portion of the movable member, that engages with the base section. Alternatively, the second mechanical stop may also be constituted by a protrusion, such as a collar, on the elongated portion of the movable member, that engages with the base section.
The movable member may be arranged to move substantially linearly, or linearly, relative to the base section between the first position and the second position. Other movement paths of the movable member, including for example curved movement paths, are conceivable.
A magnetic field outside the base section may be substantially neutral, or neutral, when the electro permanent magnet adopts the first polarity. In the variant comprising a first electro permanent magnet arranged in a first base section and a second electro permanent magnet arranged in a second base section, the magnetic field outside the first base section may be substantially neutral when the first electro permanent magnet adopts the first polarity and the magnetic field outside the second base section may be substantially neutral when the second electro permanent magnet adopts the first polarity.
The permanent magnet and the electro permanent magnet may be polarized in the same direction when the electro permanent magnet adopts the second polarity. The actuator may further comprise a battery for powering the power controller. An external power supply may alternatively be employed for supplying electrical power to the power controller. In case the actuator comprises a first electro permanent magnet arranged in a first base section and a second electro permanent magnet arranged in a second base section, one power controller may be associated with each electro permanent magnet or one common power controller may be used in common.
According to a further aspect, there is provided a lock device comprising an actuator according to the present disclosure. When the actuator is used with a locking device, the actuator may constitute a blocking mechanism of the locking device. The actuator according to the present disclosure may replace many blocking mechanisms in conventional lock devices, for example blocking mechanisms driven by a solenoid, a motor or a voice coil.
According to one variant, the lock device is constituted by a lock cylinder. In this case, the lock cylinder may comprise a stationary structure and a cylinder core rotatably accommodated in the stationary structure, wherein the first position of the movable member constitutes a disconnecting position in which the cylinder core is allowed to rotate relative to the stationary structure, and wherein the second position of the movable member constitutes an interconnecting position in which the movable member engages both the cylinder core and the stationary structure such that the cylinder core is prevented from rotating relative to the stationary structure.
According to a further variant, the lock device is constituted by a lock case. In this case, the lock case may comprise a follower unit having a hub and a coupling device, wherein coupling device is movable under control of the actuator between an engaging position where two parts of the hub are engaged and a disengaging position where the two parts of the hub are disengaged.
According to a further aspect, there is provided a handle device for operating doors, windows and the like, comprising an actuator according to the present disclosure. In addition to the actuator, the handle device may comprise a first element rotatable about an axis, a second element rotatable about the axis, a coupling device movable under control of the actuator between an engaging position where the first element and the second element are engaged and a disengaging position where the first element and the second element are disengaged. The first element may be constituted by a handle grip or a boss and the second element may be constituted by a handle escutcheon or a cylindrical end section.
According to a further aspect, there is provided a method for operating an actuator comprising at least one base section, at least one permanent magnet arranged in the base section, at least one electro permanent magnet arranged in the base section, and a movable member comprising at least one magnetic target section, the method comprising providing the electro permanent magnet with a first polarity such that a magnetic field outside the base section is substantially neutral; switching the polarity of the electro permanent magnet from the first polarity to a second polarity such that the permanent magnet and the electro permanent magnet combine to generate a magnetic field acting on the magnetic target section such that the movable member moves from a first position relative to the base section to a second position relative to the base section. The actuator for the method may be of any type according to the present disclosure.
In case the method is used with an actuator comprising a first permanent magnet and a first electro permanent magnet arranged in a first base section and a second permanent magnet and a second electro permanent magnet arranged in a second base section, the method may further comprise providing the first electro permanent magnet with a first polarity such that a magnetic field outside the first base section is substantially neutral; switching the polarity of the first electro permanent magnet from the first polarity to a second polarity such that the first permanent magnet and the first electro permanent magnet combine to generate a magnetic field acting on the magnetic target section and such that the movable member moves from a first position relative to the first base section and the second base section to a second position relative to the first base section and the second base section. The method may further comprise switching the second electro permanent magnet from a second polarity to a first polarity, at substantially the same time as the first electro permanent magnet is switched from the first polarity to the second polarity, such that a magnetic field outside the second base section is substantially neutral.
The method may further comprise switching the polarity of the second electro permanent magnet from the first polarity to the second polarity such that the second permanent magnet and the second electro permanent magnet combine to generate a magnetic field acting on the magnetic target section and such that the movable member moves from the second position relative to the first base section and the second base section to the first position relative to the first base section and the second base section. The method may further comprise switching the first electro permanent magnet from the second polarity to the first polarity, at substantially the same time as the second electro permanent magnet is switched from the first polarity to the second polarity, such that a magnetic field outside the first base section is substantially neutral.
Further details, advantages and aspects of the present disclosure will become apparent from the following embodiments taken in conjunction with the drawings, wherein:
In the following, an actuator comprising an electro permanent magnet and a movable member arranged to move between a first position and a second position, lock devices comprising the actuator, a handle device comprising the actuator and a method for operating the actuator, will be described. The same reference numerals will be used to denote the same or similar structural features.
The permanent magnet 18 may for example comprise a Neodymium alloy and the electro permanent magnet 20 may for example comprise an Alnico alloy. In
The pole pieces 16 may for example be made of relay steel, such as Hiperco® alloy. At least the right pole piece 16 may have a smooth exterior surface to minimize air gaps.
A coil 22 is wound around the permanent magnet 18 and the electro permanent magnet 20. The number of windings of the coil 22 may vary. The coil 22 may comprise copper wirings.
The actuator 10 further comprises a power controller 24. The power controller 24 is in this example powered by a battery 26. The power controller 24 is configured to apply current pulses to the coil 22 such that magnetic fields are generated. The power controller 24 may comprise switches, a pulse control transistor and a flyback diode for protecting the pulse control transistor. The battery 26 may provide a high power voltage supply (e.g. maximum 60V and maximum 20 A). Alternatively, the power controller 24 may be connected to a charged capacitor optimized for the specific pulse for the electro permanent magnet 20.
The actuator 10 further comprises a movable member 28. The movable member 28 of this example is arranged to move linearly along a movement axis 30. In
In this example, the pole pieces 16, the permanent magnet 18, the electro permanent magnet 20 and thus the entire base section 14 are cylindrical. The movable member 28 is guided within the cylindrical base section 14.
The movable member 28 comprises an elongated portion and a head portion 34. The head portion 34 comprises a magnetic target section 36 of a material strongly responsive to magnetic fields. The movable member 28 further comprises a first mechanical stop 38, here implemented as a collar on the elongated portion and a second mechanical stop 40, here constituted by an inclined surface on the head portion 34.
The actuator 10 further comprises a resetting element 42. In this example, the resetting element 42 is constituted by an elastic element in the form of a spring connected between the base section 14 and the movable member 28 and encircling the movable member 28. The resetting element 42 pushes the movable member 28 in the first direction 32 such that the first mechanical stop 38 engages the base section 14, more specifically the left pole piece 16 of the base section 14.
By applying a current pulse to the coil 22 of sufficient duration and level, a magnetic field is generated that switches the polarity of the electro permanent magnet 20 from a first polarity to a second polarity but that does not switch the polarity of the permanent magnet 18, which has a higher coercivity. The thresholds of the magnetic fields where the electro permanent magnet 20 is flipped/switches polarity and where the permanent magnet 18 is flipped, depends on the coercivity of the respective material.
The applied current pulse may for example have a duration of between 30 μs to 750 μs, such as between 50 μs to 450 μs, such as between 75 μs to 300 μs, such as 100 μs to 200 μs, such as 150 μs. Several current pulses may for example be spaced 10 ms in time. The power supply voltage may for example be 10 V to 40 V, such as 20 V to 30 V.
Since electric power is supplied only for a short time when flipping the polarity of the electro permanent magnet 20, it is possible to save energy while ensuring safety and reliability. In addition, since electric power is supplied only when flipping the polarity of the electro permanent magnet 20, there is no temperature rise. This prevents heat from being generated from the actuator 10.
By applying a current pulse in the coil 22 of sufficient duration and level in a reverse direction, the polarity of the electro permanent magnet 20 can be switched from the second polarity to the first polarity. As a consequence, the magnetic field outside the base section 14 is again substantially neutral and the resetting element 42 pushes the movable member 28 in the first direction 32 back to the first position 12 in
The actuator 10 in
The first base section 14a comprises two first pole pieces 16a, a first permanent magnet 18a and a first electro permanent magnet 20a and the second base section 14b comprises two second pole pieces 16b, a second permanent magnet IA and a second electro permanent magnet 20b. The first permanent magnet 18a and the first electro permanent magnet 20a are arranged between the two first pole pieces 16a and the second permanent magnet 1813 and the second electro permanent magnet 20b are arranged between the two second pole pieces 16b. In this example, each of the first base section 14a and the second base section 14b is cylindrical. As shown in
The movable member 28 in
The movable member 28 in
A first coil 22a is wound around the first permanent magnet 18a and the first electro permanent magnet 20a and a second coil 22b is wound around the second permanent magnet 18b and the second electro permanent magnet 20b. The actuator 10 of the example in
The actuator 10 in
In the first position 12 of
In order to move the movable member 28 from the first position 12 in
At the same time, when the second electro permanent magnet 20b has been flipped from the second polarity in
The lock device 50 in
The cylinder core 56 is axially fixed by means of a cylinder lock pin 68 engaging a circumferential groove on the cylinder core 56. The tailpiece 62 is axially fixed by means of a tailpiece lock pin 70 engaging a circumferential groove on the tailpiece 62.
The base section 14 and the movable member 28 of the actuator 10 are arranged within the cylinder core 56 and the power controller 24 and the battery 26 are arranged within the knob 58. In
The lock case 72 of the example in
The handle device 86 of this example further comprises an activating member 102 and an engaging member 104, here implemented as a ball. The activating member 102 is movable along the handle rotational axis 96 within the cylindrical end section 98. The engaging member 104 is movable in a radial hole 106 of the cylindrical end section 98. The activating member 102 comprises a waist section 108. The activating member 102, the engaging member 104, the cylindrical end section 98 and the boss 100 form a coupling device 110.
In
If the handle grip 88 (see
The handle grip 88 is therefore disengaged from the handle spindle 94 such that the handle grip 88 is allowed to turn freely in relation to the handle spindle 94, thereby enabling a disengaged state of the handle device 86, a so-called free-swiveling function. In this position, it is therefore not possible, by means of the handle grip 88, to operate a tumbler, an espagnolette bolt or any other device to which the handle spindle 94 may be coupled. Thus, when the actuator to adopts the second position 46, the coupling device 110 adopts a disengaging position where the first element (the boss 100) and the second element (the cylindrical end section 98) are disengaged.
While the present disclosure has been described with reference to exemplary embodiments, it will be appreciated that the present invention is not limited to 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 intended that the present invention may be limited only by the scope of the claims appended hereto.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1751574-3 | Dec 2017 | SE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2018/083591 | 12/5/2018 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2019/121000 | 6/27/2019 | WO | A |
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| 20200392758 A1 | Dec 2020 | US |
