Patent Description:
Swing door operators are found in many different places and are very common in e.g. hospitals, care homes, schools and offices. In many of these places, the swing door operators are used to control fire doors, i.e. doors that are designed to withstand fire and/or heat for a minimum period of time. In order for these doors to function correctly and to ensure preservation of e.g. building fire cells, there are specific requirements for swing door operators when used to control fire doors. A swing door operator is typically required to fulfill certain safety standards, e.g. EN <NUM> and EN <NUM>. When used to control a fire door, further requirements apply such as those specified in the normative annex A of EN <NUM>. The mentioned standards are but a selection of the abundance of international standards that are applicable to swing door operators. One thing that most of the standards have in common, is that they place very stringent requirements on a swing door operator.

The requirements cover vast areas of operation and many different parameters have to be controlled and within certain limits in order for the swing door operator to fulfill the requirements. One such parameter is the torque of the door, both when opening the door and when closing the door. According to standards, the required torque is varying through the opening and closing action and is thus dependent on the angular position of the door leaf.

The requirements listed above are applicable to swing doors operators regardless if they are e.g. electric or hydraulic and the requirements are valid also during power failures. Controlling the torque and the travel speed during closing and opening is simple when having electricity and a controller, but the system has to work also in a powerless mode.

In <CIT>, a door driving mechanism for connecting a door operator to a swing door leaf and fulfilling e.g. EN <NUM> is provided. The door driving mechanism comprises a guiding member fixedly arranged to the door leaf; and a driving arm at one end being rotationally driven by the door operator, wherein said driving arm is slidably connected to the guiding member at a fixed position in relation to the door leaf.

One problem with the prior art is that is very difficult to tune the parameters controlling the closing speed and torque in a powerless system.

<CIT> discloses an automatic door control system which uses microcontrollers to control four drive transistors and a drive motor connected in an H-bridge circuit. The microcontrollers use pulse width modulation to control the speed of the drive motor.

From the above it is understood that there is room for improvements.

An object of the present invention is to provide a new type of swing door operator which is improved over prior art and which eliminates or at least mitigates the drawbacks discussed above. More specifically, an object of the invention is to provide a swing door operator that enables the control of the speed of a door leaf also in a powerless mode or operation. These objects are achieved by the technique set forth in the appended independent claims with preferred embodiments defined in the dependent claims related thereto.

In a first aspect, a swing door operator for moving at least one door leaf between a first position and a second position is provided. The swing door operator is arranged to operate in a powered mode and a powerless mode. The swing door operator comprises a permanent magnet DC motor that is arranged to move the door leaf at least from the second position to the first position in the powered mode. Further to this, the swing door operator comprises a mechanical drive unit that is arranged to move the door leaf from the first position to the second position in the powerless mode. Also, the swing door operator comprises, in the powerless mode, a resistive device arrangement electrically connected in parallel with the permanent magnet DC motor. The resistive device arrangement is arranged to limit a current generated by the permanent magnet DC motor in response to the movement of the door leaf from the first position to the second position by means of the mechanical drive unit, and comprises at least two resistive devices. With two devices it is possible to select which one to use and if both are used simultaneously, higher accuracy can be achieved since total tolerances due to e.g. spread of component characteristics is reduced. The swing door operator further comprises at least one position switch arranged to sense an intermittent position of the door leaf and to switch which one of the at least two resistive devices that is operatively connectable in parallel with the permanent magnet DC motor depending on the intermittent position of the door leaf. By switching resistive element depending on the position of the door leaf, it is possible to have different speeds of the door leaf at different parts of the distance between the first position and the second position - all in the powerless mode.

In one variant of the swing door operator, the mechanical unit is further arranged to store energy mechanically when the door leaf is moved from the second position to the first position. This allows the mechanical drive unit to store energy when the movement of the door leaf is provided by the permanent magnet DC motor. Further, this means that there will always be energy mechanically stored in the mechanical drive unit when the door leaf is not in the first position.

In a further variant of the swing door operator, said move of the door leaf from the first position to the second position in the powerless mode by the mechanical drive unit is provided by releasing the mechanically stored energy. This means that this movement is provided by mechanically stored energy and is consequently provided without the need of external power.

In another variant, the swing door further comprises a control unit arranged to control the permanent magnet DC motor. The control unit allows for accurate and power efficient control and verification of the permanent magnet DC motor and also the door leaf.

In yet another variant of the swing door operator, the control unit is operatively connected to a control circuit. The control circuit enables the control unit to be a thinner client, not having to have motor control blocks integrated.

In an even further variant of the swing door operator, the control circuit comprises an H-bridge. The H-bridge allows for accurate control of the permanent magnet DC motor.

In another variant of the swing door operator, it further comprises a power switch arranged to, when the swing door operator operates in the powerless mode, disconnect the control unit and/or the control circuit from the permanent magnet DC motor and to connect the resistive device arrangement in parallel with the permanent magnet DC motor. Only having the resistive device connected to the motor enables a controlled discharge of current generated by the motor. The other devices will also affect the current generated and the drive circuits etc. would have to be construed in a way such that it did not provide a second parallel connection across the motor in the powerless mode.

In another variant of the swing door operator, one of said at least two resistive devices of the resistive device arrangement is a tunable resistive device. A tunable resistive device allows for the current generated to be tuned either per swing door operator or at the time of installation. It will also be possible to compensate for drift of the system due to e.g. ageing at later stages in the lifetime of the swing door operator. In summary, it will be possible to more accurately, adaptively and customizably control the speed of the door leaf in the powerless mode.

In a further variant of the swing door operator, the tunable resistive device of the resistive device arrangement comprises at least one semiconductor element. The semiconductor element allows for cheap and accurate ways of controlling the resistance of the resistive device.

In an even further variant of the swing door operator, the semiconductor element is a transistor arranged with a tunable voltage on a controlling terminal of the transistor. The transistor allows for cheap and accurate ways of controlling the resistance of the resistive device.

In yet one variant of the swing door, the tunable voltage is provided by voltage division of a voltage at a high potential side of the transistor. The voltage is provided by the permanent magnet DC motor and will be proportional to the movement of the door leaf, consequently the voltage of the controlling terminal of the transistor and, in turn, the resistance of the resistive element, will depend on the movement of the door leaf.

In one variant of the swing door, the voltage division is further provided by a potentiometer. The potentiometer allows for tunability and makes it possible to customize the resistive element depending on e.g. design of door leaf etc..

In another variant of the swing door operator, the voltage division is provided by at least one potentiometer and at least one resistor. The combination of a potentiometer and a resistor allows for substantially the full range of the potentiometer to be used without saturating or choke the transistor.

In one variant of the swing door, the potentiometer is a non-volatile digital potentiometer. This allows the voltage of the controlling terminal of the transistor and the resistance of the resistive device to be electrically c. Since the potentiometer is non-volatile, it keeps its settings in the powerless mode.

In a further variant of the swing door operator it is operatively connected to a control system and arranged to receive instructions comprising a resistive setting for the non-volatile digital potentiometer from the control system. This allows remote control of the swing door operator and enables the testing and tuning of the system without sending personnel to the location of the swing door operator.

In yet another variant of the swing door operator, the at least one position switch is a lock kick switch arranged to sense when the intermittent position of the door leaf is less than between <NUM>-<NUM>° from the second position, preferably below <NUM>° from the second position. Detecting these particular positions is important since there are regulatory speed requirements for the final degrees of movement of the door leaf and the speed of the door leaf still has to be high enough for the door leaf to fully close and form a tight seal with the door frame.

In another variant of the swing door, the second position corresponds to the door leaf being closed and the first position corresponds to the door leaf being open. This is the typical configuration for fire doors.

In a second aspect, a method is presented for controlling the swing door operator as shown in the first aspect. The method comprises detecting a powerless mode of the swing door operator, providing the resistive device arrangement in parallel with the permanent magnet DC motor, and limiting, by the resistive device arrangement, the current generated by the permanent magnet DC motor in response to the movement of the door leaf from the first position to the second position by means of the mechanical drive unit.

The method further comprises the steps of detecting an intermittent position of the door leaf, and switching, depending on the intermittent position of the door leaf, which one of the at least two resistive devices of the resistive device arrangement that is operatively connected to the permanent magnet DC motor. By switching resistive element depending on the positon of the door leaf, it is possible to have different speeds of the door leaf at different parts of the distance between the first positon and the second position - all in the powerless mode.

Embodiments of the invention as defined by the attached independent claims, as well as related examples not falling within the scope of the invention, will be described in the following; references being made to the appended diagrammatical drawings.

Hereinafter, certain embodiments will be described more fully with reference to the accompanying drawings. Related examples, not falling within the scope of the invention as defined by the attached independent claims, will also be described. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the invention, such as it is defined in the appended claims, to those skilled in the art.

Throughout this disclosure different terms and phrasings will be used. A door leaf may, in some sections of the disclosure, be referred to as a door. This is for simplicity reasons and the skilled person will, from context, know that the interpretation of the phrases are the same.

In <FIG>, a schematic view of a swing door assembly <NUM> is shown. The swing door assembly comprises a swing door operator <NUM>, a door leaf <NUM> and a doorframe <NUM>. The door leaf <NUM> is connected to the doorframe <NUM> via one or more hinges <NUM> and the swing door operator <NUM> is operatively connected to the door leaf <NUM> via an axle and lever assembly <NUM> arranged such that the swing door operator <NUM> can control the position of the door leaf <NUM>.

The swing door assembly <NUM> is typically arranged to move the door leaf <NUM> between a first position O and a second position C. This is exemplified in <FIG> showing a top schematic view of a swing door assembly <NUM> (the swing door operator <NUM> is not shown) mounted in a wall <NUM>. The a door leaf <NUM> may be in the first position C, <FIG>, the second position O, <FIG>, or in an intermediate position I, <FIG>, which may mean any position between the first O and the second position C. This is but an example and what constitutes the first position O and the second position C will, in this disclosure, depend on the configuration of the swing door operator <NUM>. If an electrically powered swing door operator <NUM> is assumed, the second position C of the door leaf <NUM> is the positon that the swing door operator <NUM> travels to when it operates in a powerless mode. The powerless mode may be due to power failures in which case many swing door operators <NUM> are configured such that the second position C corresponds to the door leaf being closed, as shown in <FIG>. This is typically the case with fire doors where the door closes to limit the spread of fire. In other cases of power failure or loss of power, the swing door operator <NUM> may be configured to fully open in the second position C. This may be the case when evacuation is the main purpose of the door assembly <NUM>.

The swing door operator <NUM> will typically comprise a mechanical drive unit <NUM> that ensures that the door leaf <NUM> is placed in the second positon C in the powerless mode. One example of how a swing door operator <NUM> comprising a mechanical drive unit <NUM> may be arranged in order to move the door leaf <NUM> to the second position C in the powerless mode will be explained with reference to <FIG>. In <FIG>, the swing door operator <NUM> is arranged to place the door leaf <NUM> in the second positon C and in <FIG>, the swing door operator <NUM> is arranged to place the door leaf <NUM> in the first position O. The swing door operator <NUM> comprises an electrical motor <NUM> arranged to drive the axle and lever assembly <NUM> via e.g. a disc <NUM>. Note that the actual connection between the electrical motor <NUM>, the axle and lever assembly <NUM> and the disc <NUM> is left out of the illustrations in order to simplify the explanation. This connection may be a direct connection but may also be a complex arrangement with gears and drives. The disc <NUM> is eccentrically connected to a rod <NUM> such that when the disc <NUM> rotates, the rod <NUM> is moved in a substantially linear movement. This is illustrated by the comparison of <FIG> wherein it can be seen that the rod <NUM> has been moved horizontally. Note that the rod <NUM> is shown as being directly connected to the disc <NUM>, this is for illustrative and simplified explanation purposes. An actual implementation may comprise a geared and complex connection between the rod <NUM> and the disc <NUM>. With continued reference to <FIG>, as the rod <NUM> is pulled horizontally by the rotation of the disc <NUM>, the mechanical drive unit <NUM>, illustrated as a spring <NUM> in <FIG>, is compressed. The energy storage of the mechanical drive unit <NUM> is accomplished by the electrical motor <NUM> providing energy to the mechanical drive unit <NUM>. In the transition from <FIG>, this is seen as compression of the spring <NUM> thus mechanically storing energy. If the swing door operator <NUM> would, when in the first or intermediate position I,O, suffer from a power failure, or if it was instructed to operate in a powerless mode, the mechanical drive unit <NUM> will release its mechanically stored energy. In <FIG>, this equals to the spring <NUM> expanding, pushing the rod <NUM> horizontally and forcing a rotation of the disc <NUM>. The scenario can be illustrated as the transition from <FIG>.

The mechanical drive unit <NUM> has been illustrated as a spring <NUM>, but it should be emphasized that any suitable means for mechanically storing energy may be used. An alternative, not illustrated, may be a simple weight connected to the door leaf <NUM> by a string that extends from the door leaf <NUM> to the weight via e.g. an anchor point in the doorframe <NUM>. Such an arrangement will lift the weight when the door leaf <NUM> is moved to the first position O by a force and the weight will move the door leaf <NUM> to the second positon C when the force is removed.

From the teaching presented, it can be derived that as the mechanical drive <NUM> releases its mechanically stored energy, the electrical motor <NUM> will be forced to rotate, this is unless a mechanical solution disconnects the electrical motor <NUM> from the mechanical drive <NUM>. This forced rotation of the electrical motor <NUM> is one inventive aspect realized by the inventor of this disclosure.

Electrical motors <NUM> are well known in the art and a simplified cross sectional schematic view of an electrical motor <NUM> is shown in <FIG>. The electrical motor <NUM> of <FIG> comprises a stationary part, a stator <NUM>, typically connected to or part of a housing <NUM> of the electrical motor <NUM>. The electrical motor <NUM> further comprises a rotational part, a rotor <NUM>, arranged inside the stator <NUM>. One particular variant of an electrical motor <NUM> is a Permanent Magnet Direct Current, PMDC, motor <NUM>. In a PMDC motor <NUM>, the stator <NUM> typically comprises an even number of radially magnetized permanent magnets arranged with alternating magnetic polarization around the housing <NUM> of the PMDC motor <NUM>. The rotor <NUM> comprises a number of coils and a commutator where the commutator is arranged to transfer electrical power, typically through brushes although brushless motors are also available, from a power source to the coils of the rotor <NUM>. The commutator will typically be provided with two connectors external to the electrical motor <NUM> providing connection means for supplying a DC voltage to the PMDC motor <NUM>. The coils are arranged such that the current from the power source induces a magnetic flux in the stator and the stator <NUM> consequently serves as a return path for the magnetic flux. This interaction between the coils and the permanent magnets causes a torque in and a rotation of the rotor <NUM>. Reversing the polarity of the voltage supplied to the PMDC motor <NUM> will reverse the rotational direction of the rotor <NUM>. Subjecting the rotor <NUM> to a torque will allow the PMDC motor <NUM> to act a generator in the form of a dynamo. This means that the magnetic flux caused by the rotation of the rotor <NUM> will induce a current in the coils.

Having the electrical motor <NUM> of the swing door operator <NUM> realized as a PMDC motor <NUM> will, when the mechanical drive unit <NUM> forces a rotation of the PMDC motor <NUM>, cause the PMDC motor <NUM> to generate a current IG. The function of the PMDC motor <NUM> will, in this scenario, be much like that of a dynamo.

As mentioned earlier, one challenge with swing door operators <NUM> is that the requirement for automatic closing and opening speed are valid also in powerless situations. This means it is necessary to control the speed of movement of the door fram <NUM> also when automatically transitioning from the first position O to the second positon C in powerless mode. By taking advantage of the current IG generated by the PMDC motor <NUM> in response to the mechanical drive unit <NUM> transitioning the door leaf <NUM> from the first position O to the second position C, the speed of the transitioning can be controlled.

In <FIG>, the speed control of the door leaf is realized by the introduction of a resistive device <NUM> in parallel with the PMDC motor <NUM>. The resistive device <NUM> is arranged to limit the current IG generated by the PMDC motor <NUM>. This is all in accordance with the very well known Ohm's law which is known to the skilled person and no further details regarding this will be given. When the PMDC motor <NUM> acts as a generator, the resistive device <NUM> will limit the current possible to induce in the coils, the magnetic flux generated by the rotation of the rotor <NUM> and consequently the rotational speed of the rotor <NUM>. This is all caused by the inherent properties of the PMDC motor <NUM> and the skilled person is well versed in these effects. The resistive device <NUM> may be provided with a positive connection terminal <NUM> arranged to receive the current IG generated by the PMDC motor <NUM>. The resistive device <NUM> may further be provided with a negative connection terminal <NUM> arranged to output the current IG.

The resistive device <NUM> may be any one of, a plurality of or a combination of known resistive devices <NUM>, e.g. a resistor, a potentiometer, a digital potentiometer, a semiconductor device etc. Within the scope of the invention as defined by the attached independent claims, the resistive device <NUM> is comprised in an arrangement that comprises at least two resistive devices.

In <FIG>, one embodiment of the resistive device <NUM> is realized as a semiconductor device in the form of a transistor <NUM>. The transistor <NUM> is provided with a controlling terminal <NUM> corresponding to, depending on the type of transistor used, e.g. the gate or the base of the transistor <NUM>. Further to this, the transistor <NUM> comprises a high potential terminal <NUM> corresponding to, depending on the type of transistor used, the collector or the source of the transistor <NUM>. Also, the transistor comprises a low potential terminal <NUM> corresponding to, depending on the type of transistor used, e. g, the emitter or the drain of the transistor <NUM>. In order to control the current IG generated when the PMDC motor <NUM> acts as a generator, the transistor <NUM> is provided with a controlling voltage at the controlling terminal <NUM> of the transistor <NUM>. It is well known that a voltage at the controlling terminal <NUM> of a transistor is used to control the conductivity of the transistor <NUM>. The conductivity will, when used as disclosed herein, be comparable to an impedance. However, this controlling voltage may, as shown in <FIG>, be the result of a voltage available at the high potential terminal <NUM> subjected to a voltage division. The voltage division may be provided by a high side impedance Zs connected between the high potential terminal <NUM> and the controlling terminal <NUM> of the transistor <NUM> and a low side impedance ZD connected between the controlling terminal <NUM> and the low potential terminal <NUM> of the transistor <NUM>. Note that the voltages and potentials mentioned in the explanation given above are typically differential voltages or potentials referencing the low potential terminal <NUM>, i.e. the controlling voltage at the controlling terminal <NUM> of the transistor is the differential voltage between controlling terminal <NUM> and the low potential terminal of the transistor <NUM>. Consequently, the term high potential terminal <NUM> or side is referring to a side with a higher potential than that of a low potential terminal <NUM> or side.

The voltage available at the high potential terminal <NUM> will be a provided by the permanent magnet DC motor <NUM> and will be proportional to the movement of the door leaf <NUM>. Consequently, the voltage at the controlling terminal <NUM> of the transistor <NUM> and, in turn, the resistance of the resistive element <NUM>, will depend on the movement of the door leaf <NUM>. In other words, the circuitry will act as a closed loop control system.

Either of the impedances ZD, Zs shown in <FIG> may, as seen in <FIG>, be replaced with or extended with e.g. a three terminal potentiometer Zr. Depending on the setting of the potentiometer Zr, the voltage division between the high potential terminal <NUM> and the low potential terminal <NUM> of the transistor will change. Consequently, the voltage of the controlling terminal <NUM> will change and with that the source-drain/collector-emitter conductivity of the transistor <NUM>. Typically, the embodiment shown in <FIG> will also comprise either of the impedances ZD, Zs in order to ensure that the transistor <NUM> never fully opens or closes regardless of the setting of the potentiometer ZP.

In <FIG>, a block diagram of one embodiment of the swing door operator <NUM> is shown. The swing door operator <NUM> comprises a control unit <NUM> that operatively connects to the electrical motor <NUM> via a control circuit <NUM>. The electrical motor <NUM> may be connected to a transmission <NUM> or transmission mechanism <NUM> before it connects to e.g. the door leaf <NUM>, the doorframe <NUM> or the wall <NUM>. As mentioned before, the mechanical drive unit <NUM> may be connected to the electrical motor <NUM> or to the door leaf <NUM>. The mechanical drive unit <NUM> may also be connected to the transmission <NUM> or transmission mechanism <NUM>. Typically, the door swing operator <NUM> will be connected to a power source, not shown, arranged to supply power to the door swing operator <NUM> and its active components <NUM>, <NUM>, <NUM>, <NUM>.

The control unit <NUM> may be any suitable control unit <NUM> e.g. a microprocessor, MCU, DSP, PLC etc. The control circuit <NUM> may be any suitable control or driving circuitry and may depend on the control unit <NUM> chosen. The control circuit <NUM> may, in some embodiments, comprise an H-bridge for driving the electrical motor <NUM> and in some embodiments it may be a straight forward electrical network directly connecting the control unit <NUM> to the electric motor <NUM> when e.g. the control unit <NUM> comprises motor driving circuitry - as is the case with some MCUs.

In <FIG>, a block diagram is presented depicting the control circuit <NUM> with a simplified H-bridge arranged to control the electrical motor <NUM>. The H-bridge comprises four switches S1-S4 arranged to control the current though the electrical motor <NUM>. A first side P of the switches S1 and S2 is typically connected to a high potential of the power supply, and a second side N of the switches S3 and S4 is typically connected a low potential of the power supply. The other sides of the switches S1 and S2 are connected to the respective other sides of the switches S3 and S4, and the electrical motor <NUM> is connected in parallel with these connections as is well known by the skilled person. However, when looking at <FIG> and <FIG> and placing the resistive device <NUM> in parallel across the electric motor <NUM> this will alter the load seen by the H-bridge. Further to this, the state of switches S1-S4 will affect the impedance limiting the current IG from the electrical motor <NUM> in the powerless mode.

With reference to <FIG>, power switch <NUM> is arranged as a connection between the control circuit <NUM>, the electrical motor <NUM> and the resistive device <NUM>. Note that the control circuit <NUM> shown in the embodiment of the swing door operator <NUM> in <FIG> is an example only. As mentioned, the control circuit <NUM> may not be necessary depending on e.g. the control unit <NUM> provided, and the power switch <NUM> may in those embodiments be arranged as a connection between the control unit <NUM>, the electrical motor <NUM> and the resistive device <NUM>. The power switch <NUM> is a switch arranged such that the electrical motor <NUM> is connected in an electrically closed circuit in parallel with the control circuit <NUM> or the control unit <NUM> when the swing door operator <NUM> operates in the powered mode. When the swing door operator <NUM> operates in the powerless mode, the power switch <NUM> is arranged such that the electrical motor <NUM> is connected in an electrically closed circuit in parallel with the resistive device <NUM>. The power switch <NUM> may be realized by one or more relays, transistors or combination thereof, a switch that is in a first position in a powered mode and in a second position in a powerless mode is well known to the skilled person. The power switch <NUM> may also be remotely controlled such that its state can be changed and the swing door operator <NUM> can be forced to function in the powerless mode even if the active devices <NUM>, <NUM>, <NUM>, <NUM> are still powered. This can be useful for testing, tuning and qualifying the swing door operator <NUM>, and many of the active devices <NUM>, <NUM>, <NUM>, <NUM> may comprise control logic and sensors that can be used to ensure the function of the resistive device <NUM>. This is extra beneficial when the resistive device <NUM> is realized as a non-volatile digital potentiometer ZP since the swing door operator may be tuned and controlled remotely.

In <FIG>, the swing door operator <NUM> showing two resistive devices <NUM> is depicted. Typically, the two resistive devices <NUM> will have different resistance and/or impedance, either by means of preset fixed resistors or by variable or tunable resistive devices as described earlier with reference to e.g. <FIG>. A lock kick switch <NUM> is arranged to select which of the resistive devices <NUM> that will be connected in parallel with the electrical motor <NUM>. The circuitry shown in <FIG> is shown as comprising also the power switch <NUM>. The lock kick switch <NUM> is typically a mechanical switch that switches between the resistive devices <NUM> depending on the position of the door leaf <NUM>. The lock kick switch <NUM> is arranged to switch between the resistive devices <NUM> at a preset intermittent position I of the door leaf <NUM> and this may be accomplished in a number of different ways. The lock kick switch <NUM> may be located at the door leaf <NUM>, the doorframe <NUM> or even the wall <NUM> and arranged such that it can switch at a certain position of the door leaf <NUM>. However, a preferred solution is to place the lock kick switch <NUM> internal to the swing door operator <NUM>. This allows the lock kick switch <NUM> to detect the position of the door leaf <NUM> as a function of the position of e.g. the rod <NUM>, the disc <NUM>, the axle and lever assembly <NUM>, the electrical motor <NUM> or any other suitable part of the swing door operator <NUM>. The embodiment in <FIG> is provided with two resistive devices <NUM> and one lock kick switch <NUM>. This should not in any way be considered limiting, there can be any number of resistive devices <NUM> (albeit at least two) possible to connect in parallel with the electrical motor <NUM> via any number of lock kick switches <NUM>. The name lock kick switch <NUM> is also not to be considered limiting and it may just as well be named position switch <NUM>, and any switch not associated with a function may be used and the switches may be arranged to sense any position between the first positon O and the second position C.

One particular of e.g. the EN <NUM> standard is that the door must travel the final degrees before closing for a minimum amount time. This is to avoid the door leaf <NUM> slamming shut and risking injuries of people. There are similar requirements for swing door operators <NUM> that have the second positon C being an open positon, this is also to avoid injuries and further to reduce the risk of the door leaf <NUM> damaging e.g. a wall <NUM> or similar arranged to stop the door leaf <NUM>. Consequently, it may be beneficial to arrange the position switch <NUM> such that it switches at a positon that is relevant from a certifications perspective. In one further embodiment, the lock kick switch <NUM> is arranged to switch when the door leaf <NUM> is in an intermittent position I that is <NUM>-<NUM>° from the second positon. Preferably, the lock kick switch <NUM> is arranged to switch when the intermittent position is below <NUM>° from the second positon C. Applying this embodiment to the non-limiting example of <FIG>, the lock kick switch <NUM> will switch resistive devices <NUM> when the door leaf <NUM> is <NUM>° from closing. Detecting these particular positions is important since there are, in addition to the regulatory speed requirements for the final degrees of movement of the door leaf <NUM>, requirements on proper closing of the door. This means that the door leaf <NUM> must form a tight seal with the doorframe <NUM>, and this requires a certain speed of movement of the door leaf <NUM> in order to successfully achieve this. Too slow movement of the door leaf <NUM> will leave it resting on the doorframe <NUM> providing a gap where e.g. smoke, fire and/or heat may pass.

The switching of the position switch <NUM> will typically occur regardless if the swing door operator <NUM> operates in a powered or powerless mode. As mentioned, the implementation may be realized with or without the power switch <NUM> although an implementation with the power switch <NUM> is preferred since the resistive device <NUM> will, in this case, not affect the operation and control of the electrical motor <NUM> in a powered mode of operation and vice versa.

The embodiments listed above are, as mentioned, not limiting and the combination of different embodiments of the resistive device <NUM> may very well be combined with any combination of the power switch <NUM> and/or the lock kick switch <NUM>, within the scope of the attached independent claims. For the sake of completeness, <FIG> shows a schematic overview of one embodiment of a swing door operator <NUM> arranged to operate in a powered and a powerless mode. The mechanical drive unit <NUM> introduced in <FIG> is mechanically and operatively connected to the electrical motor <NUM>. The electrical motor <NUM> is also mechanically and operatively connected to the axle and lever assembly <NUM>, which in turn is mechanically and operatively connected to the door leaf <NUM>. The door leaf <NUM> is mechanically and operatively connected to the position switch <NUM> such that the position switch <NUM> switches depending on the position of the door leaf <NUM>. As mentioned earlier, this may be an indirect connection wherein the position switch <NUM> senses a position of e.g. the electrical motor <NUM>, the mechanical drive unit <NUM>, the axle and lever assembly <NUM> or any other suitable means for determining the position of the door leaf <NUM>. The electric circuit of <FIG> comprises the power switch <NUM>. The power switch <NUM> is arranged to switch between having the electrical motor <NUM>, typically a PMDC motor <NUM>, being controlled either by the control unit <NUM> and/or the control circuit <NUM> or by one of the resistive device <NUM> being connected by the position switch <NUM>. The position switch <NUM> is arranged to switch between the two resistive devices <NUM> depending on the positon of the door leaf <NUM>. When the power switch <NUM> is in a positon such that the electrical motor <NUM> is in a closed electrical circuit with one of the resistive devices <NUM>, any current IG generated by the electrical motor <NUM>, by means of the mechanical drive unit <NUM>, will be limited by the connected resistive device <NUM>. The mechanical drive unit <NUM> will typically force the electrical motor <NUM> to generate current IG when the door leaf <NUM> is moved from the first position O to the second position C in the powerless mode. As mentioned, in the powerless mode, the power switch <NUM> connects the resistive device <NUM> in parallel with the electrical motor <NUM>. When the door leaf <NUM> is at a location, or has passed a location, of a predefined position between the first positon O and the second positon C, the position switch <NUM> will switch and change the resistive device <NUM> connected in parallel with the electrical motor <NUM>. This will change the current that can be induced in the windings of the electrical motor <NUM> and consequently change the movement speed of the door leaf <NUM>. In other words, the door leaf <NUM> moves at a first speed that is controlled by a first resistive device <NUM> until the position switch <NUM> is triggered, after which the door leaf <NUM> moves with a second speed that is controlled by a second resistive device <NUM>. Note that the control of the speed of the door leaf <NUM> is accomplished without the need of an external power supply, the movement is driven by the mechanically stored energy in the mechanical drive unit <NUM>.

The embodiment shown with reference to <FIG> may very well in some embodiments be expanded to comprise more resistive devices <NUM> of different configuration, see e.g. <FIG> and the related description. The embodiment may even, in some variants, have one of the resistive devices realized as a short circuit. Such an embodiment would allow the door leaf <NUM> to accelerate the highest speed possible to achievable by the swing door operator <NUM> when it operates in a powerless mode. The position switch <NUM> may be expanded to have the same number of throws/positions as there are resistive devices <NUM> but this would typically require the switch <NUM> having more poles in order to allow for an efficient solution. Alternatively, the swing door operator <NUM> may be extended with further position switches <NUM> typically arranged to switch at different locations of the door leaf <NUM> somewhere between the first position O and the second position C.

Claim 1:
A swing door operator (<NUM>) for moving at least one door leaf (<NUM>) between a first position (O) and a second position (C), the swing door operator (<NUM>) being arranged to operate in a powered mode and a powerless mode and comprising:
a permanent magnet DC motor (<NUM>), arranged to move the door leaf (<NUM>) at least from the second position (C) to the first position (O) in the powered mode,
a mechanical drive unit (<NUM>), arranged to move the door leaf (<NUM>) from the first position (O) to the second position (C) in the powerless mode,
in the powerless mode, a resistive device arrangement electrically connected in parallel with the permanent magnet DC motor (<NUM>) and arranged to limit a current (IG) generated by the permanent magnet DC motor (<NUM>) in response to the movement of the door leaf (<NUM>) from the first position (O) to the second position (C) by means of the mechanical drive unit (<NUM>), characterized by
the resistive device arrangement comprising at least two resistive devices (<NUM>), and
at least one position switch (<NUM>) arranged to sense an intermittent position (I) of the door leaf (<NUM>) and to switch which one of the at least two resistive devices (<NUM>) of the resistive device arrangement that is operatively connected to the permanent magnet DC motor (<NUM>) depending on the intermittent position (I) of the door leaf (<NUM>).