Braking device, device for controlling movement of an access member, and access member system

Abstract

A braking device (12a, 12b) comprising: a hard magnet (20); a soft magnet (22) configured to switch polarity between a first polarity and a second polarity when subjected to a magnetic field and configured to retain polarity when the magnetic field is removed; an electrical coil (24) located around the soft magnet; an electrical control system (16) configured to apply a pulse of electrical current to the electrical coil to generate a magnetic field for changing the polarization of the soft magnet; and a braking element (18) comprising a magnetic target portion (28), the braking element being arranged to move to a release position (40) when the soft magnet adopts the first polarity and to move to a braking position (64) when the soft magnet adopts the second polarity due to a magnetic field generated by the combination of the hard magnet and the soft magnet and acting on the magnetic target portion.

Description

Technical Field

[0001] This disclosure generally relates to braking devices. In particular, it provides braking devices including soft magnets, means for controlling the movement of an access member, and access member systems including the means. Background Technology

[0002] Some conventional door closers consist of a spring and a hydraulic cylinder containing oil. During door opening, the spring can be gradually compressed (or otherwise deformed). The hydraulic cylinder provides damping force proportional to the door's speed. However, the use of oil may be undesirable, for example, due to poor fire safety, leakage, and low sustainability. Furthermore, the reliability of such conventional door closers is often unsatisfactory, for example, due to temperature variations and wear.

[0003] US 4973894 A discloses a door closer comprising: a force transmission shaft that rotates in response to movement of a door; a spring element operatively connected to the force transmission shaft such that opening of the door occurs against the force of the spring element; and a dynamic machine comprising a rotor assembly and a stator assembly, the rotor assembly being arranged to be force-transmittedly connected to the force transmission shaft, and the stator assembly being operatively connected to the rotor assembly. Summary of the Invention

[0004] To avoid the use of hydraulic components in door closers, the door closer may include an electric motor and a closing spring that forces the door leaf towards the closed position. When the door leaf opens and / or closes, the electric motor can act as a generator to collect electrical energy. To keep the door leaf stationary, the electric motor can act as an electric motor to make the door leaf overcome the force from the closing spring and remain stationary. For this operation, a holding current must be supplied to the electric motor. Therefore, a considerable amount of energy is consumed even when no mechanical work is being performed during the door leaf holding phase.

[0005] For most types of energy harvesting-based systems, total energy budget should be a critical concern. Therefore, reducing energy consumption is just as important as increasing the amount of energy harvested.

[0006] One object of this disclosure is to provide a braking device with low power consumption.

[0007] Another object of this disclosure is to provide a braking device that does not consume power in either the release state or the braking state.

[0008] Another objective of this disclosure is to provide a braking device with a small size.

[0009] Another objective of this disclosure is to provide a braking device with a less complex design.

[0010] Another objective of this disclosure is to provide a braking device with a cost-effective design.

[0011] Another objective of this disclosure is to provide a braking device with fail-safe operation.

[0012] Another objective of this disclosure is to provide a braking device that addresses several or all of the aforementioned objectives in combination.

[0013] Another object of this disclosure is to provide an apparatus for controlling the movement of an access member relative to a frame, which addresses one, several, or all of the aforementioned objects.

[0014] Another object of this disclosure is to provide an access component system including a frame, access components, and means, which addresses one, several, or all of the foregoing objects.

[0015] According to one aspect, a braking device is provided, comprising: a hard magnet; a soft magnet configured to switch polarity between a first polarity and a second polarity when subjected to a magnetic field, and configured to maintain polarity when the magnetic field is removed; an electric coil located around the soft magnet; an electrical control system configured to apply current pulses to the electric coil to generate a magnetic field for changing the polarization of the soft magnet; and a braking element including a magnetic target portion, the braking element being arranged to move to a release position when the soft magnet adopts the first polarity, and being arranged to move to a braking position when the soft magnet adopts the second polarity due to a magnetic field generated by the combination of the hard magnet and the soft magnet and acting on the magnetic target portion.

[0016] When a current pulse of a certain duration and level is applied to an electric coil wound around a soft magnetic material, the magnetic field generated by the current pulse flips the polarity of the soft magnetic material from a first polarity to a second polarity. Once the soft magnetic material has flipped from the first polarity to the second polarity, a hard magnetic material and a soft magnetic material combine to generate a magnetic field. This magnetic field acts on the magnetic target portion of the braking element (e.g., by attracting or repelling magnetic forces), causing the braking element to move from the release position to the braking position. Once the polarity of the soft magnetic material has switched from the first polarity to the second polarity, and the braking element has moved from the release position to the braking position, the magnetic field generated by the combination of the hard and soft magnetic materials holds the braking element in the braking position without a power source. The release position and the braking position can constitute different positions of the braking element.

[0017] When the braking element is in the release position, the braking device is in the release state. Conversely, when the braking element is in the braking position, the braking device is in the braking state. The braking device is bistable. Bistable means that the braking device can be in either the release or braking state without consuming energy, and only energy is required to switch the braking device between the release and braking states.

[0018] Hard magnets, soft magnets, and electric coils form an electro-permanent magnet (EPM). When the soft magnet adopts the second polarity, the EPM provides high magnetic force, and when the soft magnet adopts the first polarity, the EPM provides zero or near-zero magnetic force. The EPM can be stationary.

[0019] Soft magnets have lower coercivity than hard magnets. Because of their low coercivity, the polarity of soft magnets can be switched by applying a current pulse. Hard magnets, on the other hand, have high coercivity, and their polarity is unaffected by the applied current pulse. Hard magnets can include, for example, neodymium alloys such as neodymium iron boron (NdFeB), or other alloys with relatively high intrinsic coercivity. Soft magnets can include, for example, AlNiCo alloys, iron-cobalt-vanadium alloys, or other alloys with relatively low intrinsic coercivity.

[0020] Because the polarity of the soft magnet can be switched using current pulses, only a very small amount of electrical energy is required to switch the EPM, thereby enabling the braking element to move between the release and braking positions. Therefore, the braking device is an ultra-low-power braking device. The braking device can switch between the release and braking states requiring only a few mJ.

[0021] When the soft magnet adopts a second polarity, the braking element can be arranged to move to the braking position due to magnetic attraction or repulsion.

[0022] Braking devices can be used, for example, in non-hydraulic devices (e.g., door closers) to control the movement of the access member relative to the frame. However, alternative uses for braking devices are conceivable.

[0023] The braking element can be configured as a braking output component. Therefore, the braking element can engage the output component in the braking position. The energy required to switch the EPM is far less than the energy required to maintain the output component by means of an electric motor.

[0024] The braking device can be a friction braking device. In this case, the braking element can frictionally engage the output component at the braking position.

[0025] The magnetic target portion can be of any type affected by the magnetic field of the EPM. The magnetic target portion can close the magnetic circuit in the braking position of the braking element. When the braking element is arranged to move to the braking position due to attractive magnetic force, the magnetic target portion can, for example, comprise a ferromagnetic material such as a soft magnetic material. When the braking element is arranged to move to the braking position due to repulsive magnetic force, the braking element can, for example, comprise a permanent magnet.

[0026] The braking element can be forced toward the release position. For this purpose, the braking device may also include a release spring arranged to force the braking element toward the release position. Alternatively or additionally, the braking element may be arranged to be forced toward the release position by gravity.

[0027] The braking device may also include a braking hinge. In this case, the braking element can rotate about the braking hinge between a release position and a braking position.

[0028] The braking element may include a brake pad. The brake pad may be configured to frictionally engage the friction surfaces of the output member when the braking element is in the braking position to achieve braking.

[0029] The control system may include a driver for applying a first current pulse to the coil to switch the soft magnetic material from a second polarity to a first polarity, and for applying a second current pulse to the coil to switch the soft magnetic material from the first polarity to the second polarity. The control system may also include: a capacitor for applying the first current pulse to the coil to switch the soft magnetic material from the second polarity to the first polarity; a normally open switch connected in series with the driver and the coil; and a normally closed switch connected in series with the capacitor and the coil.

[0030] The capacitor can have sufficient capacitance to switch a soft magnetic material from a second polarity to a first polarity. The first current pulse can be a negative pulse, and the second current pulse can be a positive pulse.

[0031] By means of a capacitor, a normally open switch, and a normally closed switch, a first current pulse is applied through the capacitor and the coil in the event of a power outage. Therefore, it can be ensured that the braking device is always in the released state when power is lost. Thus, the control system according to this variant provides fail-safe operation. The power source can be, for example, a battery or mains power. With the aid of the power source, a control voltage can be provided to the control system.

[0032] According to another aspect, a device is provided for controlling the movement of an access member relative to a frame. This device includes a braking mechanism according to the present disclosure, arranged to brake the access member. The device may be a door closer. The access member may be a door leaf.

[0033] The device may also include an electromagnetic generator with a rotor arranged to be driven by the movement of the access member to generate electrical energy. Therefore, the device can provide energy harvesting functionality.

[0034] A generator can be composed of an electric motor configured to function as both a generator and an electric motor. The electric motor can be, for example, a BDC (brushed direct current) or BLDC (brushless direct current) type.

[0035] The control system can be powered by a generator. Therefore, the device can be an energy harvesting device, such as an energy harvesting door closer.

[0036] The device may also include an output member arranged to be contacted by the braking element when the braking element is in a braking position. For this purpose, the output member may include a friction surface for contact with the braking element (e.g., by the brake pad of the braking element).

[0037] The output member can be rotatable or linearly movable. The output member can be driven by the rotor or fixed to the rotor. In either case, a braking element (e.g., a brake pad of the braking element) can engage the output member in a braking position to brake the output member, and thereby also brake the access member.

[0038] The device may also include a transmission mechanism arranged to transmit movement of the accessing member to movement of the output member. The transmission mechanism may be a gear train comprising two or more gears. In this case, one of the gears may be fixed to the rotor. Alternatively, the transmission mechanism may be a belt drive or a chain drive.

[0039] The device may also include an input component. The input component may be fixed to the door leaf. In this case, the input component may be concentric with the door hinge of the door leaf. The input component may form part of a transmission mechanism. In this case, the input component may be a gear.

[0040] The device may also include closing springs for connection to each closing spring in the access member and the frame. The closing springs can be configured to force the access member toward a closed position relative to the frame. Therefore, the closing springs can be tensioned to store mechanical energy when the access member is opened.

[0041] The transmission mechanism may include a freewheel device configured to rotate freely as the access member moves in the opening direction. The freewheel device may include a freewheel or a one-way clutch. Regardless of the braking state, the freewheel device ensures the access member is always open. With the aid of the freewheel device, the access member can be moved to a more open position regardless of the braking position. This is advantageous for less robust individuals (such as children or the elderly). When the braking state is active and the access member is in the closed position, the access member can be gradually (e.g., by several small pushes) pushed to the open position.

[0042] When the transmission mechanism includes a freewheel mechanism, energy harvesting occurs only during the closing movement of the access member. Therefore, the freewheel mechanism makes it easier to open the access member, for example, by essentially only overcoming the force of the closing spring.

[0043] The rotor can be arranged to be driven by a transmission device.

[0044] The transmission device can be a speed-increasing transmission. In this way, the holding force required to hold the access member by braking the output member is significantly lower than the holding force required by directly braking the access member. This significantly reduced holding force, in turn, allows for a smaller braking device. Another advantage of the speed-increasing transmission is that it can drive the generator rotor at higher speeds. This enables more efficient energy harvesting and a reduction in generator size.

[0045] According to another aspect, an access component system is provided, including a frame, an access component movable relative to the frame, and means according to the present disclosure. The access component may be a door leaf.

[0046] The device can be configured to hold the access member in the open position for a selectable holding time. After this holding time, the braking device is commanded to release, causing the access member to begin closing by means of a closing spring. During the closing movement of the access member, energy can be harvested by means of a generator. The load on the generator can be controlled to control the closing speed of the access member.

[0047] The access member system may also include a closing spring, which is arranged to force the access member toward a closed position.

[0048] Attached text

[0049] Further details, advantages, and aspects of this disclosure will become apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0050] Figure 1 : schematically represents a braking device including a braking element in the released position;

[0051] Figure 2 : A schematic representation of the device after the output component has moved;

[0052] Figure 3 : A schematic representation of a device that brakes the output component when the braking element is in the braking position;

[0053] Figure 4 : This schematically represents the EPM and control system of the braking device;

[0054] Figure 5 This schematically illustrates the EPM and control system in the event of a power outage.

[0055] Figure 6 : schematically represents an access component system including a braking device; and

[0056] Figure 7: schematically represents another device that includes another braking device. Detailed Implementation

[0057] The following description includes a braking device comprising a soft magnet, a means for controlling the movement of an access member, and an access member system including the means. The same or similar reference numerals will be used to denote the same or similar structural features.

[0058] Figure 1 Device 10a is schematically shown. In this example, device 10a is a door closer. Device 10a includes a braking device 12a. The braking device 12a includes an electro-permanent magnet EPM 14, an electrical control system 16, and a braking element 18.

[0059] EPM 14 includes a hard magnet 20, a soft magnet 22, and an electric coil 24. The soft magnet 22 is configured to switch polarity between a first polarity and a second polarity when subjected to a magnetic field. Figure 1 In the middle, the soft magnet 22 has the first polarity.

[0060] The EPM 14 in this example also includes pole pieces 26. Hard magnets 20 and soft magnets 22 are arranged in parallel between the pole pieces 26. The pole pieces 26 may be made of a ferromagnetic material. An electric coil 24 is wound around the hard magnets 20 and the soft magnets 22.

[0061] The braking element 18 includes a magnetic target portion 28. The magnetic target portion 28 is illustrated herein as an arm having a material (e.g., a ferromagnetic material) that strongly responds to a magnetic field. The magnetic target portion 28 may be made of a soft magnetic material with no or low remanence. As an alternative example, the magnetic target portion 28 may form only a part of an arm or other type of component.

[0062] The braking element 18 in this example also includes a brake pad 30. The brake pad 30 is attached to the magnetic target portion 28. The brake pad 30 may be made of, for example, rubber.

[0063] The braking device 12a also includes a braking hinge 32. The braking element 18 can rotate about the braking hinge 32.

[0064] The braking device 12a in this example also includes a release spring 34 (illustrated here as a helical spring). One end of the release spring 34 is connected to a fixed structure (not shown), and the other end of the release spring 34 is connected to the braking element 18.

[0065] The braking device 12a in this example also includes a mechanical stop 36. The mechanical stop 36 is illustrated herein as a retaining pin.

[0066] The device 10a in this example also includes an output member 38a. The output member 38a in this example is a rack. The output member 38a is linearly movable along its longitudinal axis.

[0067] When the soft magnetic material 22 has a first polarity (according to) Figure 1 The hard magnet 20 and the soft magnet 22 have opposite magnetizations. Therefore, EPM 14 is in the off state, so that no or substantially no net external magnetic field is generated on the pole piece 26.

[0068] exist Figure 1 In the middle position, the braking element 18 is in the released position 40. In the released position 40, the braking element 18 is pulled by the release spring 34 to rotate about the braking hinge 32 until the braking element 18 (here, its magnetic target portion 28) contacts the mechanical stop 36. In the released position 40, the brake pad 30 is separated from the output member 38a. Therefore, the release spring 34 ensures that the output member 38a is not braked when the EPM 14 is in the off state.

[0069] The device 10a in this example also includes a door 42. Door 42 is an example of an access component according to this disclosure. Figure 1 In the middle, door leaf 42 is in the closed position 44. Door leaf 42 can be rotated from the closed position 44 to the open position.

[0070] The device 10a in this example also includes a transmission device 46a. The transmission device 46a is configured to transmit the movement of the door leaf 42 to the movement of the output member 38a. In this example, the transmission device 46a is configured to transmit the rotation of the door leaf 42 (…). Figure 1 The linear motion (clockwise) transmitted to the output component 38a is (in the middle) Figure 1 (Left side of the middle).

[0071] The transmission device 46a is a speed-increasing transmission device, exemplified here as a gear train. In this specific example, the transmission device 46a includes a first gear 48, a second gear (not visible), a third gear 50, a fourth gear 52, and a fifth gear 54. The second gear is fixed to and concentric with the third gear 50. The first gear 48 meshes with the second gear. The third gear 50 meshes with the fourth gear 52. The fourth gear 52 meshes with the fifth gear 54. The fifth gear 54 meshes with the output member 38a. The second gear is smaller than the first gear 48, the third gear 50 is larger than the second gear, the fourth gear 52 is smaller than the third gear 50, and the fifth gear 54 is smaller than the fourth gear 52.

[0072] The first gear 48 is fixed to the door leaf 42. The first gear 48 is an example of an input component according to this disclosure.

[0073] The device 10a in this example also includes an electromagnetic generator 56. The generator 56 includes a stator (not shown) and a rotor 58. In this example, a fifth gear 54 is fixed to the rotor 58. The rotor 58 is thus driven by a transmission 46a. Therefore, the rotor 58 is arranged to be driven by the rotation of the door leaf 42 to generate electrical energy. By means of the transmission 46a, the rotor 58 rotates at a higher speed than the rotational speed of the door leaf 42, thereby increasing the energy harvesting capacity of the generator 56. When the braking element 18 is in the release position 40, the door leaf 42 can be manually opened and closed as needed.

[0074] Figure 2 The device 10a schematically illustrates the door leaf 42 moving from the closed position 44 to the open position 62 in the opening direction 60. The output member 38a is moved linearly by means of a transmission device 46a. More specifically, and referring to… Figure 2 Door leaf 42 and first gear 48 rotate clockwise together, second gear and third gear 50 rotate counterclockwise, fourth gear 52 rotates clockwise, fifth gear 54 rotates counterclockwise, and output member 38a moves linearly to the left.

[0075] During the movement of door 42 in the opening direction 60, electrical energy can be collected with or without the aid of generator 56. To keep door 42 in the open position 62, EPM 14 is activated to the on state, as described below.

[0076] Figure 3 The device 10a is schematically shown when the braking element 18 is in the braking position 64. Figure 3 In this circuit, control system 16 sends a second current pulse through coil 24. This generates a second magnetic field, which causes the soft magnet 22 to change its polarity or flip from the first polarity to the second polarity. Since the hard magnet 20 has a higher coercivity than the soft magnet 22, the polarity of the hard magnet 20 is unaffected by the magnetic field. When the soft magnet 22 adopts the second polarity, the magnetization directions of the hard magnet 20 and the soft magnet 22 are aligned. Therefore, the hard magnet 20 and the soft magnet 22 combine to generate an external magnetic field. EPM 14 is thus switched on. Once the soft magnet 22 switches to the second polarity, no energy is required to keep EPM 14 on.

[0077] The external magnetic field generated by EPM 14 acts on the magnetic target portion 28 through magnetic attraction. The braking element 18 is thus forced into the braking position 64, overcoming the force of the release spring 34 (which is stretched). Therefore, EPM 14 pulls the braking element 18, forcing the brake pad 30 against the output member 38a. In the braking position 64, the brake pad 30 contacts and frictionally engages the output member 38a. The braking element 18 thus brakes the output member 38a through friction. In this way, the door leaf 42 can remain in the open position 62 without energy consumption. The door leaf 42 does not close until the braking device 12a is released again.

[0078] Since the transmission device 46a is a speed-increasing transmission device, the holding force acting on the output member 38a through the braking element 18 is significantly lower than the holding force acting directly on the door leaf 42 by the braking element 18. This allows for a reduction in the rating of the braking device 12a.

[0079] In this example, the braking element 18 (here, the magnetic target portion 28) contacts the pole piece 26 in the braking position 64. Therefore, the mechanical stop 36 and the pole piece 26 define two different positions for the release position 40 and the braking position 64, respectively.

[0080] To release the braking device 12a, the control system 16 sends a first current pulse through the coil 24. This generates a first magnetic field, which causes the soft magnet 22 to change polarity or flip from a second polarity back to a first polarity. When the soft magnet 22 adopts the first polarity, the hard magnet 20 and the soft magnet 22 are again magnetized in opposite directions, causing the EPM 14 to be in an off state, thus preventing the generation of a net external magnetic field on the pole piece 26. Therefore, the magnetic force from the EPM 14 acting on the magnetic target portion 28 stops, and the release spring 34 forces the braking element 18 to move from the braking position 64 back to the release position 40. When the door leaf 42 moves from the open position 62 back to the closed position 44, electrical energy is collected by the generator 56.

[0081] Figure 4 EPM 14 and control system 16 are schematically represented. Figure 4 The stator 66 of the generator 56 can also be seen in the image. The control system 16 also includes a driver 68. The driver 68 is configured to apply a first current pulse and a second current pulse to the coil 24 to switch the polarity of the soft magnet 22.

[0082] The control system 16 also includes a capacitor 70, a normally open switch 72, and a normally closed switch 74. The capacitor 70 is also configured to apply a first current pulse to the coil 24 to switch the soft magnetic material 22 from a second polarity to a first polarity, i.e., to switch the EPM 14 from an on state to an off state. The capacitor 70 is used for emergency closing of the door 42.

[0083] Normally open switch 72 is connected in series with driver 68 and coil 24. Normally open switch 72 is an electrically controlled switch. Normally open switch 72 is open when no voltage is applied. Normally open switch 72 closes when a (positive) voltage is applied to its control pin. Normally open switch 72 can be implemented using an enhancement-mode MOS transistor.

[0084] Normally closed switch 74 is connected in series with capacitor 70 and coil 24. Normally closed switch 74 is an electrically controlled switch. Normally closed switch 74 is closed when no voltage is applied. Normally closed switch 74 is open when a (positive) voltage is applied to the control pin of the normally closed switch. Normally closed switch 74 can be implemented using a depletion-type MOS transistor.

[0085] Figure 4 The control voltage V+ is also shown. The control voltage V+ can be, for example, +12V.

[0086] The control system 16 in this example also includes a normally closed manual switch 76. The manual switch 76 can be used to manually close the door 42, and can also be used to test the functionality of the control system 16.

[0087] The control system 16 also includes a diode 78 and a resistor 80. The resistor 80 is used to set an appropriate charging current for the capacitor 70.

[0088] exist Figure 4 In the control system 16, power is available, for example, from a battery or mains power. In normal mode, normally open switch 72 is closed, and normally closed switch 74 is open. EPM 14 is thus connected to driver 68, and capacitor 70 is charged and disconnected from EPM 14.

[0089] The control system 16 in this example also includes a data processing unit 82 and a memory 84. The memory 84 includes a computer program stored thereon. The computer program includes program code that, when executed by the data processing unit 82, causes the data processing unit 82 to perform or command the various steps described herein. For example, the data processing unit 82 can command the driver 68 to send a first pulse and a second pulse to respectively switch the EPM 14 to an off state and an on state. Furthermore, the data processing unit 82 can monitor the time period during which the braking device 12a should be in a braking state to hold the door 42 in the open position 62.

[0090] The control system 16 also includes energy harvesting electronics, which include an energy storage device, illustrated herein as a harvesting capacitor 86, and four harvesting diodes 88 arranged in a diode bridge configuration. The harvesting diodes 88 are arranged to rectify the voltage from the generator 56.

[0091] The control system 16 also includes a disconnect switch 90 and a short-circuit switch 92. Each of the disconnect switch 90 and the short-circuit switch 92 is controlled by a driver 68. Figure 4 Positive line 94 and ground line 96 are also shown. Positive line 94 and ground line 96 are connected to corresponding terminals of generator 56. In this example, disconnect switch 90 is provided on positive line 94. Each of disconnect switch 90 and short-circuit switch 92 can be implemented using transistors such as MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors).

[0092] The disconnect switch 90 is arranged to selectively disconnect from the generator 56. When the disconnect switch 90 is open, the resistance increases, and the door 42 moves relatively easily compared to when the door 42 moves to collect electrical energy.

[0093] The short-circuit switch 92 is arranged to selectively short-circuit the terminals of the generator 56 across the collecting resistor 98. When the short-circuit switch 92 is closed, the collected electrical energy is converted into heat in the collecting resistor 98. Then, the door 42 is more difficult to move compared to when the door 42 moves to collect electrical energy. Therefore, when the short-circuit switch 92 is closed, a high counter-torque is provided in the generator 56, making it more difficult to rotate the rotor 58 by means of the movement of the door 42.

[0094] By selectively controlling the disconnect switch 90 and the short-circuit switch 92, the control system 16 can selectively change the electrical load of the generator 56 to control the movement of the door leaf 42. The generator 56 thus functions as an electronic brake.

[0095] Figure 5 The diagram schematically illustrates the EPM 14 and control system 16 in the event of a power outage. For example, the power outage could be caused by a fire alarm system, a power failure, or a burglar alarm. The normally closed switch 74 will therefore close, and the normally open switch 72 will therefore open.

[0096] When power is lost, control system 16 enters emergency mode. The control voltage is then 0V. In emergency mode (or when manual switch 76 is open), EPM 14 is disconnected from driver 68, and capacitor 70 is connected to EPM 14. The discharge current from capacitor 70 ensures that soft magnet 22 adopts its first polarity, regardless of its initial polarity. Therefore, EPM 14 will be in the off state. This ensures that braking element 18 is in or in the release position 40 to release door leaf 42. Diode 78 prevents capacitor voltage from activating normally closed switch 74 and normally open switch 72.

[0097] When power is lost, the brake device 12a will always be in the released state, and the door 42 will always be open. Switching the manual switch 76 triggers the same event as during a power outage.

[0098] To provide protection against individual component failures (both open-circuit and short-circuit failures), most components of the control system 16 (e.g., normally closed switch 74, normally open switch 72, and capacitor 70) can be quadrupled and can be arranged in a series-parallel configuration.

[0099] Figure 6 Access component system 100 is schematically shown. Access component system 100 includes device 10a, which in turn includes braking device 12a. In addition to door leaf 42, access component system 100 also includes frame 102 and door hinge 104. Door leaf 42 is rotatable relative to frame 102 about door hinge 104. Figure 6 In the middle, door leaf 42 is in the open position 62. The first gear 48 is concentric with the door hinge 104 here. The braking device 12a is located inside the frame 102.

[0100] like Figure 6 As shown, device 10a also includes a closing spring 106. One end of the closing spring 106 is connected to the door leaf 42, and the other end is connected to the frame 102. The closing spring 106 forces the door leaf 42 toward the closed position 44. Therefore, the door leaf 42 can open against the force of the closing spring 106. The braking device 12a is in a braking state to hold the door leaf 42 for, for example, 5 to 10 seconds.

[0101] Figure 7 This schematically illustrates another device 10b, including another braking device 12b. A description regarding... Figures 1 to 6 The main differences.

[0102] Device 10b includes a transmission device 46b. The difference between transmission device 46b and transmission device 46a is that transmission device 46b includes a freewheel device 108. This example freewheel device 108 includes a driving member 110 and a driven member 112. The driving member 110 is fixed to the door leaf 42. The driven member 112 is fixed to the first gear 48. When the driving member 110 rotates clockwise (according to…),… Figure 7 The driven member 112 is not driven by the driving member 110. When the driving member 110 rotates counterclockwise (according to...), the driven member 112 is not driven by the driving member 110. Figure 7 The driven member 112 is driven by the driving member 110. Therefore, when the door leaf 42 moves in the opening direction 60, the free wheel device 108 is configured to rotate freely.

[0103] With the help of the freewheel mechanism 108, the door leaf 42 can always be opened. In addition, even when the braking device 12b is in the braking state, the freewheel mechanism 108 can open the door leaf 42 further.

[0104] also, Figure 7 The difference between device 10b and device 10a is that device 10b includes an output member 38b. The output member 38b is a circular member fixed to the fifth gear 54. Therefore, the output member 38b is rotatable. Due to the freewheel device 108, the output member 38b will rotate only counterclockwise. When the braking position 64 is engaged, the braking element 18 of braking device 12b brakes the output member 38b in the same manner as the braking element 18 of braking device 12a brakes the output member 38a when the braking position 64 is engaged.

[0105] Although this disclosure has been described with reference to exemplary embodiments, it will be understood that the invention is not limited to what has been described above. For example, it will be understood that the dimensions of the components can be changed as needed. Therefore, the invention is intended to be limited only to the scope of the appended claims.

Claims

1. A braking device (12a, 12b) comprising: - a hard magnet (20); - a soft magnet (22) configured to switch polarity between a first polarity and a second polarity when subjected to a magnetic field, and the soft magnet (22) is configured to retain the polarity when the magnetic field is removed; - an electric coil (24) located around the soft magnet (22); - a control system (16) configured to apply a current pulse to the electric coil (24) to generate a magnetic field for changing the polarization of the soft magnet (22); and - a braking element (18) comprising a magnetic target portion (28), the braking element (18) being arranged to move to a release position (40) when the soft magnet (22) adopts the first polarity, and the braking element (18) being arranged to move to a braking position (64) when the soft magnet (22) adopts the second polarity due to a magnetic field generated by the combination of the hard magnet (20) and the soft magnet (22) and acting on the magnetic target portion (28).

2. The brake device (12a, 12b) according to claim 1, wherein The braking element (18) is forced towards the release position (40).

3. The braking device (12a, 12b) according to claim 2, further comprising a release spring (34) arranged to force the braking element (18) towards the release position (40).

4. The brake device (12a, 12b) according to any one of claims 1 to 3, further comprising a brake hinge (32), wherein, The braking element (18) is rotatable around the brake hinge (32) between the release position (40) and the braking position (64).

5. The brake device (12a, 12b) according to any one of claims 1 to 3, wherein The control system (16) comprises: - a driver (68) for applying a first current pulse to the electric coil (24) to switch the soft magnet (22) from the second polarity to the first polarity, and a second current pulse to the electric coil (24) to switch the soft magnet (22) from the first polarity to the second polarity; - a capacitor (70) for applying a first current pulse to the electric coil (24) to switch the soft magnet (22) from the second polarity to the first polarity; - a normally open switch (72) connected in series with the driver (68) and the electric coil (24); and - a normally closed switch (74) connected in series with the capacitor (70) and the electric coil (24).

6. A device (10a, 10b) for controlling movement of an access member (42) relative to a frame (102), the device (10a, 10b) comprising a braking device (12a, 12b) according to any one of claims 1 to 5, the braking device (12a, 12b) being arranged to brake the access member (42).

7. The apparatus (10a, 10b) of claim 6, wherein The device (10a, 10b) is a door closer and the access member (42) is a door leaf.

8. The device (10a, 10b) according to claim 6, further comprising an electromagnetic generator (56) having a rotor (58) arranged to be driven by movement of the access member (42) to generate electrical energy.

9. The apparatus (10a, 10b) of claim 8, wherein, The control system (16) is powered by the generator (56).

10. The device (10a, 10b) according to any one of claims 6 to 9, further comprising an output member (38a, 38b) arranged to be contacted by the braking element (18) when the braking element (18) assumes the braking position (64).

11. The device (10a, 10b) according to claim 10, further comprising a transmission (46a, 46b) arranged to transmit movement of the access member (42) to movement of the output member (38a, 38b).

12. The apparatus (10b) of claim 11, wherein, The transmission (46b) comprises a freewheel arrangement (108) configured to freewheel when the access member (42) is moved in an opening direction (60).

13. The apparatus (10a, 10b) of claim 11, further comprising an electromagnetic generator (56) having a rotor (58), wherein, The rotor (58) is arranged to be driven by the transmission (46a, 46b) to generate electrical energy.

14. The apparatus (10a, 10b) of claim 11, wherein, The transmission (46a, 46b) is a speed increasing transmission.

15. An access member system (100) comprising: a frame (102), an access member (42) movable relative to the frame (102), and a device (10a, 10b) according to any one of claims 6 to 14.

16. The access member system (100) according to claim 15, further comprising a closing spring (106) arranged to force the access member (42) towards a closed position (44).

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