DOOR DRIVE

Description

[0001] The invention relates to a door drive for a door, comprising a drive mechanism which can be coupled to the door and has a displaceable piston element and a closing spring which acts on the piston element in the closing direction of the door, wherein in the assembled state of the door drive a movement of the door is alternately accompanied by a displacement of the piston element and a manual opening movement of the door displaces the piston element in a deflection direction against a force of the closing spring from an initial position and thereby stores mechanical energy in the closing spring for a closing movement of the door.The drive mechanism comprises a drive unit which has an electric motor unit and a pulling mechanism which can be driven by the electric motor unit, wherein a rotary movement of the electric motor unit in an opening direction of rotation can be converted into a translatory movement of the piston element by the pulling mechanism, wherein when the electric motor unit is actuated in the opening direction of rotation, the pulling mechanism pulls the piston element against the force of the closing spring from the starting position into a holding position, in which the drive unit then holds the piston element when the closing spring is tensioned, whereby the door is also held in an open position when the door drive is in the assembled state.

[0002] Purely mechanical door closers are well known and are used in countless buildings around the world. Each time a door equipped with such a door closer is opened, a mechanical energy storage device, usually a spring, is activated. After the user releases the door, this stored mechanical energy is used to automatically close the door. These purely mechanical door closers thus enable a door to close securely after each use during normal operation.

[0003] Since mechanical energy is stored in the closer spring during each opening process, this additional mechanical energy, which is required compared to simply opening the door, must be provided by the door user. However, this can cause difficulties for certain groups of people, such as young, elderly, and / or physically disabled people, or even make it completely impossible for them to use a door equipped with such a purely mechanical door closer. A door equipped with such a purely mechanical door closer can also pose an insurmountable obstacle for autonomous vehicles such as cleaning robots.

[0004] Furthermore, especially in larger buildings or building complexes, a smoke and heat extraction system (SHEVS system) may be provided to ensure a sufficient supply of fresh air and the rapid and safe removal of smoke from the building in the event of a fire. This protects occupants in the building and, in particular, protects them from poisoning and suffocation. Large air intake areas, such as those provided by open doors, are advantageous for such SHEVS systems. However, doors equipped with simple mechanical door closers are kept closed by these doors, so they cannot be considered for SHEVS systems.

[0005] In principle, it is possible to install a separate drive for opening the door in addition to a purely mechanical door closer. However, since both the door closer and the additional drive must be installed, mounting positions are often limited and installation is complex. Furthermore, in addition to the additional costs incurred for such a drive, it requires more space.

[0006] Alternatively, fully automatic door operators can be used. However, the disadvantage of such automatic door operators is that they are more expensive in terms of purchase, installation, maintenance, and operation.

[0007] EP 1 428 966 A2 relates to a door opener having a drive, a gear connected thereto and a force transmission element connected to the gear, which is at least indirectly connected to the door to be operated, wherein the gear is designed as a linear gear.

[0008] DE 27 51 859 A1 relates to a door closer comprising an elongated housing in which a spring-loaded piston is displaceable in two opposite axial directions, and a rotatable locking shaft connected to the door leaf and provided with a pinion, which cooperates with a rack formed on this piston. The spring is biased in the direction of closing the door.

[0009] US 4 580 365 A relates to a door closer, in particular to a hydraulically operated door closer, with a closer shaft which is loaded in the closing direction by a spring arrangement and which guides the movable member of a piston-cylinder arrangement, wherein between the pressure chamber and the pressureless chamber there is another displaceable piston which has a check valve opening towards the pressure chamber and a blocking valve which is electromagnetically supported in the blocking position.

[0010] The object of the present invention is to at least partially remedy the above-described disadvantages of known door closers and door drives of the prior art, and to do so in the simplest and most reliable manner possible. In particular, the object of the present invention is to create a door drive that enables the independent opening and secure holding of a door, while simultaneously retaining the purely mechanical closing functionality and, moreover, being designed to be space-saving and cost-effective.

[0011] The above object is achieved by the patent claims. In particular, the object is achieved by a door drive having the features of independent claim 1. Further features and advantages of the door drive according to the invention emerge from the subclaims, the description, and the drawings.

[0012] According to the invention, the object is achieved by a door drive for a door, in which the pulling mechanism has a transmission device that can be driven rotatably by the electric motor unit, a coupling element that is connected to the piston element, in particular in one piece, and a connecting part arranged between the transmission device and the coupling element, wherein the connecting part is connected to the transmission device in a rotationally fixed manner and, in particular, is axially displaceable to a limited extent and is coupled to the coupling element via a threaded connection, or vice versa.

[0013] The division of the traction mechanism into transmission device, coupling element, and connecting part allows different tasks of the traction mechanism to be fulfilled by a specially designed element of the traction mechanism. Thus, the transmission device and the coupling element each represent those parts of the traction mechanism that are directly connected to the motor unit and the piston element, respectively. For example, the coupling element can preferably even be formed integrally with the piston element. The transmission device, in turn, is intended to transmit the drive provided by the motor unit, usually rotary, to the coupling element. For this purpose, the transmission device can comprise, for example, shaft and bearing elements, but also a transmission gear.The connecting part, in turn, can form a mechanical operative connection between the transmission device and the coupling element, and thus, overall, between the motor unit of the drive unit and the piston element. Due to the rotationally fixed connection with either the transmission device or, conversely, the coupling element, and the simultaneous threaded connection with the coupling element or, conversely, the transmission device, a rotary drive movement of the transmission device can be particularly easily converted into a translational movement, in particular a pulling movement, of the coupling element and thus of the piston element.The limited axial displaceability of the connecting part enables, on the one hand, the transmission of force between the transmission device and the coupling element to be realized by the limitation, and, on the other hand, the displaceability enables a decoupling between the relative position of the coupling element and the transmission device, in order, for example, not to hinder the opening of the door when the drive unit is inactive.

[0014] A door drive according to the invention is primarily intended for use on doors and can therefore be used with them and arranged accordingly. In addition, however, other locking devices for building openings, for example windows or skylights, can also be equipped with and operated by a door drive according to the invention. The drive mechanism of the door drive, for example comprising a lever linkage or a lever-slide rail unit, can enable the door drive to close automatically. During manual, but also during all other, opening processes of the door, the drive mechanism, which can comprise or contain, for example, a pinion and a toothed rack, moves the piston element from its initial position along its deflection direction against the force of the closer spring, whereby mechanical energy is stored in the closer spring.Once the door is released, the energy stored in the closing spring is released again, and the piston element is pushed back to its original position in the housing, counter to the direction of deflection. This causes the door to close via the mechanical connection described above, formed by the drive mechanism.

[0015] The drive unit can preferably also be arranged or integrated in the housing of the door drive or flanged thereto. An electric motor unit, which is or can be connected to an external and / or internal electrical power supply, drives a pulling mechanism. The motor unit can also be designed together with a gearbox as a combined geared motor unit. The pulling mechanism is at least temporarily mechanically operatively connected to both the motor unit and the piston element and can, in particular, convert the rotary movement provided by the motor unit into a translatory movement. When operatively connected to the piston element, the piston element is pulled by the pulling mechanism against the force of the closing spring when the motor unit is running, whereby the door connected to the door drive is automatically opened via the drive mechanism.

[0016] In other words, the additional drive unit integrated into the door drive, in particular its motor unit and pull mechanism, enables a powered opening of the door. The motor unit is preferably operated until the piston element has reached a holding position corresponding to a desired and / or preset opening position of the door. This opening position can be reached, for example, at a maximum opening angle, but also at an angle smaller than the maximum opening angle.

[0017] Overall, this enables the door to open automatically without the user of the door, whether a real person or, for example, an autonomous vehicle, having to exert any force on the door. The force or mechanical energy required to open the door is generated by the drive unit, which is activated by the user, for example, via a button or a wired or wireless activation signal. Activating the opening process via an externally or internally generated trigger signal is also conceivable and can therefore be provided.

[0018] Furthermore, the invention provides that the door is held in the reached open position by the drive unit after the motorized opening process. This holding can occur, for example, for a situational and / or predetermined period of time so that the open door can be walked through when triggered. Alternatively, the holding can also occur permanently, or at least until the holding is deactivated, for example by a user or an externally or internally generated deactivation signal. After the expiry of the period of time or due to deactivation, the drive mechanism then stops holding the door in its open position so that the mechanical energy stored in the closing spring is released and the door closes automatically again.Preferably, the entire system consisting of door and door drive is then returned to its initial position, in which normal operation with the door drive as a classic, purely mechanical door closer is possible again.

[0019] However, it is particularly preferred that the drive unit permanently enables the door to be held in the open position, in particular regardless of whether the drive unit is supplied with electrical power or not. This particularly enables the use of a door drive according to the invention as an element of a smoke and heat extraction system. When the door drive according to the invention is triggered, for example in the event of a fire, the drive unit of the door drive is activated and opens the door. The drive unit is designed in such a way that it subsequently continues to hold the door open, in particular even in the event of a power failure. In this way, the open door can act as a secure supply air area for smoke or heat extraction in the context of a smoke and heat extraction system.

[0020] Furthermore, the door drive according to the invention can be characterized in that the electric motor unit and / or the pulling mechanism are arranged in series with the piston element and / or the closing spring in the deflection direction of the piston element. In other words, an arrangement of the various elements of the door drive according to the invention in series along the deflection direction means that these corresponding elements of the door drive, in particular the electric motor unit and / or the pulling mechanism as well as the piston element and / or the closing spring, are arranged next to one another or one after the other along the deflection direction, wherein the individual elements can also overlap one another. The property of the drive unit to be able to pull the piston element of the door drive according to the invention in the deflection direction against the force of the closing spring can be realized in a particularly simple and compact manner in this way.

[0021] The door drive according to the invention can also be designed such that the pull mechanism is coupled to the piston element in such a way that a manual opening movement of the door is still possible while the piston element is being pulled by the drive unit from the starting position into the holding position. This can preferably be made possible, for example, by the pull mechanism being or being capable of being coupled to the piston element in a force-transmitting manner only on one side, for example by a form-fitting stop on only one side, in particular by two components within the pull mechanism that are translationally movable relative to one another. In other words, this form-fitting connection is only effective in the deflection direction, but not in the opposite direction to the deflection direction.In this way, the pulling mechanism can pull the piston element along the deflection direction, while at the same time, if the piston element moves faster along the deflection direction than the pulling mechanism, the piston element can precede the pulling movement.

[0022] In other words, a user can also open the door faster than the drive unit can allow. A force exerted on the door by a user during the drive-driven opening process thus leads, in particular, only to a faster opening of the door and not to a load and / or even damage to the door drive according to the invention. Preferably, it can also be provided that even after completion of the motorized opening movement of the door by the drive unit, i.e., when the drive unit holds the door in its open position, a further opening movement of the door performed by a user is possible.

[0023] Furthermore, in the door drive according to the invention, it can be provided that the pulling mechanism is designed such that when the electric motor unit is actuated against the opening direction of rotation, there is no drive-effective connection between the drive unit and the piston element, so that the electric motor unit does not transmit any force, in particular no translational force, to the piston element. Preferably, an existing drive-effective connection between the drive unit and the piston element is thus released when the electric motor unit is actuated against the opening direction of rotation. Due to the absence of a drive-effective connection in this direction of rotation, the door drive according to the invention can also provide the functions usually provided by purely mechanical door closers, in particular the automatic closing of an open door after it has been opened.Furthermore, the holding of the door in its open position by the drive unit of the drive mechanism can be actively ended by actuating the electric motor unit against the opening direction of rotation, whereby the piston element is then pushed back into its original position by the mechanical energy stored in the closing spring and the door is closed.

[0024] The door drive according to the invention can particularly preferably be characterized in that the drive unit is designed to be self-locking, wherein the electric motor unit is preferably designed to be self-locking, in particular the electric motor unit is designed as a self-locking geared motor unit with a stepper motor and a planetary gear, and / or the pulling mechanism is designed to be self-locking. Self-locking in the sense of the invention means that the drive unit is designed such that, even without a supply of electrical energy, it withstands the force exerted by the tensioned closing spring on the piston element in its holding position and thus holds the door in its open position. In other words, the term self-locking in the sense of the invention includes that the drive unit is designed to be self-locking and is adapted to the respective closing spring used in the door drive.

[0025] The self-locking property of the drive unit makes it possible for the door to be held in its open position by the door drive according to the invention even in the event of a failure of the electrical power supply, in particular, for example, for use of the door drive according to the invention as part of a smoke and heat extraction system. For this purpose, either the electric motor unit or the pulling mechanism, but preferably both elements, can be designed to be self-locking, either individually or in combination. One possible self-locking design of the motor unit is, for example, a configuration of the motor unit as a geared motor unit with a stepper motor and a planetary gear. The use of other types of electric motors or gear units is also possible if they are suitable, in particular with regard to the self-locking properties of the correspondingly designed geared motor unit.The pulling mechanism, in turn, can, for example, have a threaded connection with interlocking threaded sections, which can also have a self-locking effect within the meaning of the invention through a suitable choice of, for example, a pitch of the threaded sections.

[0026] The door drive according to the invention can also be designed such that the drive unit comprises an electrical energy storage device for pulling the piston element at least once against the force of the closing spring from the starting position into the holding position. In particular, when the door drive according to the invention is used as part of a smoke and heat extraction system, it is necessary to sufficiently ensure that the door can be opened in the event of a fire. By means of an electrical energy storage device in which sufficient electrical energy is stored for the door to be opened at least once, this safety for the opening process can be significantly increased. Even in the event of an immediate failure of an external electrical power supply for the door drive according to the invention, the opening process can thus be carried out reliably and the desired supply air area can thus be created.

[0027] In the door drive according to the invention, it can also be further provided that the drive unit comprises control and / or regulating electronics for receiving trigger signals and, based thereon, for controlling the electric motor unit. In other words, in this embodiment of the door drive according to the invention, the control and / or regulating electronics are and / or can be integrated into the door drive. The function of the drive unit can thus be triggered directly by the door drive according to the invention. External control devices that are spatially separated from the door drive can thus be avoided, whereby interruptions in communication connections, which can in particular be wired and / or wireless, between the door drive according to the invention and external control and / or regulating devices, which cannot be ruled out as a source of error, for example in the event of a fire, can be avoided.

[0028] The door drive according to the invention can also be designed such that, in the assembled state of the door drive, the holding position of the piston element corresponds to a door opening angle between greater than 0° and 180°, in particular between 75° and 105°, preferably 90°. A door opening angle of greater than 0° and 180°, in particular between 75° and 105°, preferably 90°, can ensure a sufficiently large supply air area through the open door in the context of a smoke and heat extraction system. This door opening angle, corresponding to the holding position of the piston element, can be the maximum opening angle of the door, but can also correspond to any smaller opening angle.

[0029] In a further development, the door drive according to the invention can be characterized in that the closer spring is designed as a helical spring, and the coupling element and / or the connecting part and / or parts of the transmission device are arranged inside the closer spring. Helical springs represent particularly preferred embodiments of closer springs because they have a hollow space within them. By arranging at least parts of the tension mechanism in this hollow space, a particularly compact design of the entire door drive according to the invention can be achieved.

[0030] The door drive according to the invention can also be further developed in that the coupling element is tubular and / or the transmission device has a drive shaft, in particular one that extends into the tubular coupling element, and / or the connecting part has a nut element. A drive shaft represents a particularly simple embodiment of a transmission device for transmitting the drive movement provided by the motor unit, in particular the rotational drive movement. Inserting the drive shaft into the tubular coupling element enables a further increase in the compactness of the structure of the entire pull mechanism and, as a whole, of the door drive according to the invention.To convert the rotary movement of the drive shaft into a translatory movement of the coupling element, which pulls the piston element, a nut element as a connecting part or part of the connecting part is also a particularly compact and space-saving option. In particular, the nut element can have an internal thread or an external thread for the threaded connection to the transmission device or the coupling element. Preferably, in this embodiment, the closing spring is also designed as a helical spring, and the coupling element, the nut element, and at least part of the drive shaft are arranged inside the closing spring.

[0031] Particularly preferably, the door drive according to the invention can be further developed in such a way that the drive shaft is designed at least in sections as a threaded spindle and the nut element is arranged on the threaded spindle with an internal thread adapted to the threaded spindle and is mounted in the tubular coupling element in a rotationally fixed and axially displaceable manner, wherein when the drive shaft is driven in the opening direction of rotation, the axial displaceability is limited, so that the coupling element and the piston element follow an axial movement of the nut element along the threaded spindle, but not when the drive shaft is driven opposite to the opening direction of rotation.In this preferred embodiment of the door drive according to the invention, the rotational movement of the drive shaft is converted into a translational movement of the nut element along the deflection direction via a threaded connection formed by the threaded spindle of the drive shaft and an internal thread of the nut element. This is because the rotationally fixed arrangement of the nut element in the coupling element blocks any rotational movement of the nut element following the rotation of the threaded spindle. By limiting a possible axial displacement of the nut element in the coupling element, an axial positive connection is formed between the nut element and the coupling element when the limit is reached by the nut element. This results in the coupling element and thus the piston element being pulled in the deflection direction.A particularly simple and safe conversion of the rotary drive movement of the electric motor unit into a pulling of the piston element into its holding position can be made possible in this way.

[0032] According to a first further developed embodiment of the door drive according to the invention, it can be provided that at least one bolt is arranged radially on the nut element, wherein the at least one bolt engages in an axially extending groove in the coupling element, wherein, furthermore, when the drive shaft is driven in the opening direction of rotation, an axial movement of the nut element relative to the coupling element is limited by a positive abutment of the at least one bolt against an axial surface of the groove, in particular an axial end of the groove or at least a partial section of the groove. In this embodiment, the nut element has at least one bolt protruding in the radial direction. Preferably, the nut element can also have a plurality of such bolts, for example two such bolts diametrically opposite one another with respect to the threaded spindle, each of which engages in a groove.The engagement of at least one bolt in the groove of the coupling element ensures, on the one hand, the rotationally fixed arrangement of the nut element in the coupling element. The abutment of the bolt on the axial surface, which blocks axial displacement of the nut element relative to the coupling element, in turn enables the coupling element and thus the piston element to follow the axial movement of the nut element along the rotating threaded spindle. For this purpose, the groove can be designed, for example, as a simple groove extending linearly along the deflection direction. Alternatively, the groove can also be shaped essentially L-shaped, for example, with the limiting axial surface being arranged on the lower transverse arm of the L-shaped groove. The vertical arm of the L-shaped groove can even extend with its upper end to the axial end of the coupling element.This makes assembly of the drive unit easier because the bolt can simply be inserted into this upper end of the vertical arm when assembling the pulling mechanism.

[0033] According to an alternative development, the door drive according to the invention can be provided with the nut element having a non-circular, in particular hexagonal, outer contour, wherein the nut element is mounted in a rotationally fixed and axially displaceable manner in an inner contour of the tubular coupling element, which inner contour corresponds to the outer contour. Furthermore, the coupling element is provided with a stop element which, when the drive shaft is driven in the opening direction of rotation, positively limits an axial movement of the nut element relative to the coupling element. In this embodiment, the rotationally fixed mounting of the nut element in the coupling element is achieved by the correspondingly matched non-circular outer and inner contours of these elements. At the same time, this rotationally fixed mounting also enables an axial displaceability of the nut element in the coupling element.To limit this axial displacement, which, as already described above, enables the piston element to be pulled in the deflection direction, the coupling element here has a stop element against which the nut element abuts in a form-fitting manner at a specific position in the coupling element. Upon further rotation of the threaded spindle in the opening direction, the coupling element, and thus the piston element, then follows the axial movement of the nut element along the threaded spindle. Particularly with a uniform hexagonal design of the outer contour of the nut element and the inner contour of the coupling element, a commercially available screw nut can preferably be used as the nut element in this embodiment.

[0034] In a further alternative development, the door drive according to the invention can be designed such that a common longitudinal axis of the threaded spindle and the internal thread is arranged offset from a central axis of the coupling element, wherein the coupling element is provided with a stop element which, when the drive shaft is driven in the opening direction of rotation, positively limits an axial movement of the nut element relative to the coupling element. In contrast to the embodiment described above, in this embodiment the outer contour of the nut element and the inner contour of the coupling element can be cylindrical with a circular cross-section. In this embodiment, the rotationally fixed mounting of the nut element in the coupling element is achieved via the radial offset between the central axis of the coupling element and the common longitudinal axis of the threaded spindle and the internal thread.During a rotational movement of the threaded spindle, this offset causes the nut element to rest against the inner contour of the coupling element. The stop element, in turn, ensures that, from a certain axial position of the nut element and coupling element, the coupling element, and thus the piston element, is pulled along the deflection direction.

[0035] Furthermore, the door drive according to the invention can be characterized in that the drive shaft has a drive section for rotationally driving the nut element, wherein the nut element has a continuous central opening adapted to the drive section of the drive shaft for rotational driving, wherein the drive shaft passes through the central opening with its drive section, wherein the nut element further has an external thread that engages with an internal thread of the tubular coupling element, and the drive shaft has an axial limiting element that positively limits an axial movement of the nut element relative to the drive shaft when the drive shaft is driven in the opening direction of rotation. In this embodiment, the nut element is connected directly to the coupling element by a threaded connection.The rotational drive of the nut element is achieved via the drive section of the drive shaft and the correspondingly designed central opening of the nut element. The drive section and the central opening are designed to be coordinated with one another in such a way that rotation of the drive shaft and thus of the drive section leads to rotation of the nut element, for example through parts of the drive section being in positive contact or striking contact with corresponding surfaces of the central opening. In particular, the drive section and central opening are designed in such a way that axial displacement of the nut element on the drive section along the deflection direction is generally possible. The limiting element can block this axial displacement of the nut element from a certain position of the nut element.This results in a subsequent further rotation of the drive shaft, and thus of the drive section and the nut element, being transmitted via the threaded connection to the coupling element in such a way that the latter is pulled along the deflection direction.

[0036] In a further development, the door drive according to the invention can be designed such that the drive section has an axially constant, non-circular, in particular hexagonal, cross-section and the central opening is adapted to this cross-section of the drive shaft and thus the nut element is mounted on the drive shaft in a rotationally fixed and axially displaceable manner, wherein the drive shaft has an end stop projecting radially beyond the cross-section as an axial limiting element. The axially constant cross-section makes the above-described axial displacement of the nut element along the drive section particularly easy. The non-circular shape of the cross-section and the adapted shape of the central opening enable a positive transmission of a rotation of the drive shaft to the nut element.The end stop, as an axial limiting element, enables axial displacement of the nut element along the drive section to be blocked from a certain position, thus allowing the piston element to be pulled along the deflection direction.

[0037] Alternatively, in the door drive according to the invention, it can also be provided that the drive section has a cylindrical central part and a sector part projecting radially therefrom, and the central opening of the nut element has a cylindrical middle section corresponding to the central part and a sector opening corresponding at least to the size of the sector part, wherein the nut element has a sector cover complementary to the sector opening and with a stop arranged on a side facing away from the electric motor unit, wherein with the sector part aligned with the sector opening there is no drive-effective connection between the drive unit and the piston element and when the drive shaft is driven in the opening direction of rotation, the sector part abuts positively against the stop of the sector cover and further forms the axial limiting element.In this embodiment of the door drive according to the invention, the nut element and the drive section are designed in the sense of a keyhole arrangement. As long as the drive section is aligned such that its sector part coincides with the sector opening of the central opening, there is no drive-effective connection between the motor unit and the piston element, whereby the door drive according to the invention can only perform its purely mechanical automatic closing functionality. When the electric motor unit is actuated in the opening direction, the drive shaft and thus the drive section rotate such that the sector part engages behind the sector cover. When the sector part strikes the stop, a rotation in the opening direction is transmitted from the drive shaft to the nut element.Since the sector part also rests against the axial surface of the sector aperture at the same time, axial movement of the nut element is blocked, which, as a result, enables the piston element to be pulled in the deflection direction via the threaded connection between the nut element and the coupling element. To ensure that the piston element is held in the achieved holding position, both the axial surface of the sector aperture and the section of the sector part resting against this surface are preferably oriented transversely, preferably perpendicularly, to the deflection direction.

[0038] Alternatively, the door drive according to the invention can also be further developed in that the transmission device comprises a lifting actuator, a lifting rod mounted on the drive shaft and displaceable along the deflection direction by the lifting actuator, and at least one engagement element mounted on the drive shaft and switchable between an engaged position and a release position by the lifting rod. In its engaged position, the at least one engagement element forms the drive section and the limiting element of the drive shaft by engaging in the correspondingly adapted central opening of the nut element. In other words, in this embodiment, the drive-effective connection between the drive unit and the piston element can be actively configured or disengaged.In its engaged position, the engagement element forms a positive connection with the correspondingly adapted central opening of the nut element both radially and axially, so that on the one hand a rotational movement of the drive shaft is transmitted to the nut element, and on the other hand an axial displacement of the nut element along the drive shaft is prevented. As a result, in particular provided by the threaded connection between the nut element and the coupling element, a rotation of the drive shaft in the opening direction of rotation leads to a pulling of the coupling element and thus of the piston element along the deflection direction. At the same time, conversely, with the engagement element in its release position, the drive-effective connection can be released, which can ensure, for example, secure closing of the door, driven by the mechanical energy stored in the closer spring.

[0039] The door drive according to the invention can preferably be further developed such that the lifting actuator has a setting spring acting on the lifting rod along the deflection direction, wherein the setting spring exerts a force on the at least one engagement element in the direction of its engagement position via the lifting rod. In other words, the setting spring holds the drive unit in a state in which the drive-effective connection exists between the drive unit and the piston element. This has the particular advantage that after the piston element has been pulled into its holding position, the engagement element remains in its engagement position even in the event of a power failure, and thus the piston element can be held in this holding position by the drive unit. As a result, the door remains in its open position even without an external power supply. This is necessary when used in a SHEV system, particularly as an air supply area.

[0040] Furthermore, the door drive according to the invention can be further developed such that the at least one engagement element is a pawl or a ball lock pin. This list is not exhaustive, so further designs of engagement elements switchable by a lifting rod are also possible. In particular, the appropriate engagement element can be selected for different door drives with different requirements.

[0041] Furthermore, in the door drive according to the invention, it can be provided that the drive unit has a contour sleeve which is mounted rotatably about the transmission device, in particular the drive shaft, and secured against axial movement along the deflection direction and has a guide contour, wherein the coupling element has a guide pin which engages in the guide contour, wherein the guide contour together with the guide pin forms a type of ballpoint pen mechanism which, after a movement of the coupling element in the deflection direction, holds the coupling element in an at least partially deflected position, in particular the holding position, and only enables a complete return to its starting position after a renewed movement of the coupling element in the deflection direction.This ballpoint pen mechanism thus makes it possible, in particular, to ensure that the coupling element is held in a deflected position, particularly the holding position, even if the electrical power supply is completely lost. Use of the door drive according to the invention in a smoke and heat extraction system can thus be made even safer. In particular, such a mechanism, similar to a ballpoint pen mechanism and specifically adapted for use in a smoke and heat extraction system, also makes it possible to hold the door open after it has been manually opened.

[0042] The invention is described below with reference to the figures. Elements with the same function and mode of operation are provided with the same reference numerals in the figures.

[0043] They show schematically: Fig. 1 an embodiment of a door drive according to the invention as a combination of door closer and drive with a drive shaft, Fig. 2 detailed views of the embodiment of the door drive from Fig. 1 in different states, Fig. 3Detail views of a first modification of the embodiment of the door drive from Fig. 1 in different states, Fig. 4Detail views of a second modification of the embodiment of the door drive from Fig. 1 in different states, Fig. 5Detail views of a third modification of the embodiment of the door drive from Fig. 1 in different states, Fig. 6Detail views of a fourth modification of the embodiment of the door drive from Fig. 1 in different states, Fig. 7 a nut element and a drive section of a drive shaft of another embodiment of the door drive according to the invention, Fig. 8 an embodiment of a door drive according to the invention with a lifting actuator and pawls, Fig. 9 detailed views of the embodiment of the door drive from Fig. 8 in different states, Fig. 10 an embodiment of a door drive according to the invention with a lifting actuator and locking ball pin, Fig. 11 detailed views of the embodiment of the door drive from Fig. 10 in different states, Fig. 12 an embodiment of a door drive according to the invention with a type of ballpoint pen mechanism, and Fig. 13 detailed views of the embodiment of the door drive from Fig. 12 in different states.

[0044] Fig. 1 shows a door drive 100 according to the invention as a combination of door closer and drive. Like all door drives 100 according to the invention, this has a drive mechanism 112 with a piston element 114 and a closer spring 116, which are arranged in a housing 110. The piston element 114 is displaceably mounted along a deflection direction 90 in the housing 110 and, through mechanical coupling to a drive shaft 118, enables connection to a door. In particular, this coupling, which is formed, for example, by a pinion on the drive shaft 118 and a rack on the piston element 114, alternately accompanies a movement of the door with a displacement of the piston element 114.

[0045] Thus, an opening movement of the door via the drive mechanism 112 causes the above-described displacement of the piston element 114 along the deflection direction 90, particularly against the force of the closing spring 116. Thus, with each opening of the door, mechanical energy is stored in the closing spring 116, which can subsequently be released again after the door is released. The closing spring 116 then pushes the piston element 114 back to its original position, and the door is automatically closed, in particular.

[0046] The door drive 100 according to the invention is characterized in that it additionally comprises a drive unit 10 which, driven by a motor unit 12 of the drive unit 10, can pull the piston element 114, via a pulling mechanism 14 of the drive unit 10, from the starting position into a holding position against the force of the closing spring 116 along the deflection direction 90. The motor unit 12 can be designed, in particular, as a geared motor unit 12 in which an electric motor and a gear are integrated into a common structural unit. In the assembled state of the door drive 100 according to the invention, this holding position of the piston element 114 can, for example, correspond to an opening angle of the door between greater than 0° and 180°, in particular between 75° and 105°, preferably 90°.

[0047] Furthermore, the drive unit 10 is designed such that, after pulling, it subsequently holds the piston element 114 in the achieved holding position, whereby the door is correspondingly held in its open position. In this way, on the one hand, a motorized opening of the door is enabled, whereby the door can also be opened by groups of people who are unable to open the door manually, in particular for heavy doors such as fire doors and / or doors equipped with a mechanical door closer. This advantage can also be made possible for autonomous vehicles, such as cleaning robots. Furthermore, by holding the door in its open position by the drive unit 10, the door drive 100 according to the invention can preferably be used as part of a SHEV system to provide an air supply area.

[0048] In order to ensure this opening of the door independently of an external power supply, which can also fail in the event of a fire, the door drive 100 according to the invention can, as shown, comprise an electrical energy storage device 16 for pulling the piston element 114 at least once against the force of the closing spring 116 from the starting position into the holding position. This energy storage device 16 can, as also shown, be integrated into the control and / or regulating electronics 18 of the door drive 100 according to the invention. The control and / or regulating electronics 18 are provided in particular for receiving trigger signals and, based thereon, for controlling the electric motor unit 12. Due to the above-described integration of the energy storage device 16 into the control and / or regulating electronics 18, in particular, the loss of an external power supply can already be recognized by the control and / or regulating electronics 18 as a trigger signal.

[0049] In the Fig. 1 In the illustrated embodiment of the door drive 100 according to the invention, the pull mechanism 14 of the drive unit 10 has a drive shaft 22, which is designed at least in sections as a threaded spindle 24. The drive shaft 22 and the threaded spindle 24 form, in particular, parts of a transmission device 20 of the pull mechanism 14, are directly connected to the motor unit 12 of the drive unit 10, and are rotationally driven thereby. Configuring the closer spring 116 as a helical spring enables at least parts of the pull mechanism 14 to be arranged inside the helical spring, thereby enabling a particularly compact design of the door drive 100 according to the invention.

[0050] Furthermore, the Fig. 1 The pull mechanism 14 shown has a coupling element 70 which, as shown, can preferably be formed integrally with the piston element 114 and furthermore can be formed tubularly. In addition to the drive shaft 22 and the coupling element 70, a connecting part 50 forms a third element of the pull mechanism 14, wherein the connecting part 50 is arranged between the coupling element 70 and the drive shaft 22 and is mechanically operatively connected thereto or at least operatively connectable thereto.

[0051] The connecting part 50 can be designed as a nut element 52, particularly as shown when using a drive shaft 22 as the transmission device 20, and can be mounted on the transmission device 20, in particular the drive shaft 22, or the coupling element 70, in a rotationally fixed and axially displaceable manner to a limited extent. This connecting part 50 is then connected to the corresponding other element, i.e., either to the coupling element 70 or to the transmission device 20, via a threaded connection.

[0052] Furthermore, as also shown by way of example, the electric motor unit 12, the pulling mechanism 14, the piston element 114 and the closing spring 116 can be

[0053] The piston element 114 can be arranged in series in the deflection direction 90. The axial limitation of the displaceability of the nut element 52 relative to the coupling element 70 is preferably translationally unilateral and is set such that, from a certain position of the nut element 52, with the drive shaft 22 driven in the opening direction of rotation, the piston element 114 follows an axial movement of the nut element 52 along the threaded spindle 24.

[0054] Overall, the piston element 114 is thereby pulled along the deflection direction 90 into its holding position and subsequently held there. For this holding, the drive unit 10 can or should be designed to be self-locking, wherein the electric motor unit 12 is preferably designed as a geared motor unit 12, particularly preferably comprising a stepper motor and a planetary gear, and is thus already designed to be self-locking in itself. Due to the design with a threaded connection, the pulling mechanism 14 can also be designed to be self-locking in itself. The self-locking can also be provided or reinforced by the interaction of the drive unit 10 and the pulling mechanism 14.This takes into account that the drive unit 10 is self-locking within the meaning of the invention if, even without a supply of electrical energy, it resists the force exerted by the tensioned closing spring 116 on the piston element 114 in its holding position. In other words, the drive unit 10 is self-locking, adapted to the respective closing spring 116 used in the door drive 100.

[0055] Conversely, the one-sided translational limitation of the displaceability of the nut element 52 relative to the coupling element 70 also makes it possible for a manual opening movement of the door to continue while the piston element 114 is being pulled by the drive unit 10 from the starting position into the holding position. Furthermore, this also ensures that actuation of the electric motor unit 12 opposite to the opening direction of rotation releases a drive connection between the drive unit 10 and the piston element 114, so that the electric motor unit 12 no longer transmits any force to the piston element 114. In other words, when the drive connection is released, the movement of the piston element 114, driven by the closing spring 116, is released again, and the door then closes automatically.

[0056] In the Fig. 1 In the special embodiment of the door drive 100 according to the invention shown, two bolts 56 are arranged diametrically opposite one another on the nut element 52. These bolts 56 extend radially outward and engage in two corresponding axially extending grooves 76 in the coupling element 70. Due to the mechanical interaction, in particular a positive stop, between the bolts 56 and the axial edges of the grooves 76, with corresponding rotation of the threaded spindle 24 as part of the drive shaft 22 and the resulting translational movement of the nut element 52 along the deflection direction 90, the coupling element 70 and thus the piston element 114 are pulled in the deflection direction 90.

[0057] The interaction between the bolts 56 and the grooves 76 is Fig. 2 explained in more detail using three different states in a detailed view of the pull mechanism 14. Figure A shows a rest state with the door closed, Figure B a manually driven opening movement of the door, and Figure C an opening movement of the door caused by the drive unit 10. Figures A, B, and C show the threaded spindle 24, the nut element 52 with the bolts 56, the coupling element 70, and partly also the piston element 114, as well as the grooves 76 with their axial surfaces 78 at the axial ends of the grooves 76.

[0058] The idle state with the door closed (Figure A of the Fig. 2 ) forms a basic starting position. The bolts 56 are arranged in the grooves 76; without drive by the threaded spindle 24 or by a manually triggered displacement of the coupling element 70 or the piston element 114, no power transmission takes place. During a manually triggered opening process of the door (Figure B of the Fig. 2 ), the piston element 114 and thereby the coupling element 70 arranged thereon, in particular, for example, in one piece, is displaced along the deflection direction 90. Due to the axial extension of the groove 76, this displacement takes place without being hindered by the bolts 56 arranged on the nut element 52. In other words, the normal function of the door is ensured by the presence of the door drive 100 according to the invention, in particular its drive unit 10 (see Fig. 1 ) is not obstructed. After the door is released, it returns, driven by the return force of the closing spring 116 (see Fig. 1 ) and without being influenced by the pulling mechanism 14 of the drive unit 10, back into the configuration shown in Figure A. When the threaded spindle 24 is driven in the opening direction (Figure C of the Fig. 2 ) the rotationally fixed mounting of the nut element 52 in the coupling element 70 causes the nut element 52 to move along the deflection direction 90 on the threaded spindle 24, with its bolts 56 abutting the axial end of the grooves 76 on their axial surfaces 78, so that the bolts 56 pull the coupling element 70 and thus the piston element 114 along, whereby the door is opened.

[0059] The following Fig. 3 bis 6 show various embodiments of the pulling mechanism 14, again explained in more detail using three different states of a detailed view of the respective pulling mechanism 14. Here, as already shown in Fig. 2 In each case, Figure A also shows a rest state with the door closed, Figure B shows a manually driven opening movement of the door, and Figure C shows an opening movement of the door caused by the drive unit 10. In the following, the respective special features of the pulling mechanism 14 are discussed in particular, for the illustrated states, reference is also made to the above description. Fig. 2 referred to.

[0060] Fig. 3 shows a tension mechanism 14 having an alternative configuration of a bolt 56 and a groove 76 in the coupling element 70. In particular, in this embodiment, the groove 76 is substantially L-shaped with a vertical arm portion and a transverse arm oriented at right angles thereto. The defining axial surface 78 is arranged on the transverse arm of the L-shaped groove 76. This configuration can also be referred to as a simplified keyhole arrangement. The vertical arm portion of the L-shaped groove 76 extends with its upper end to the axial end of the coupling element 70. The nut element 52 also has a cylindrical central portion extending along the deflection direction 90. When the bolt 56 is arranged on the vertical arm of the groove 76 (Figure A, B), a movement of the coupling element 70, and thus of the piston element 114 and the drive mechanism 112 arranged thereon, is decoupled from the bolt 56 and thus from the nut element 52.Only when driven by the motor unit 12 in the opening direction of rotation does the nut element 52 rotate and the bolt 56 is arranged in the lower cross arm of the L-shaped groove 76, where it then strikes in a rotationally fixed manner on the one hand and also makes positive contact with the axial surface 78 at the axial end of the cross arm on the other hand, and as a result the piston element 114 is pulled in the deflection direction 90.

[0061] In Fig. 4 a further alternative embodiment of the pull mechanism 14 is shown, in which the nut element 52 has a hexagonal outer contour 54. Furthermore, the coupling element 70 is provided with an inner contour 72 designed corresponding to the outer contour 54, whereby the nut element 52 is mounted in the coupling element 70 in a rotationally fixed and axially displaceable manner. Furthermore, at the axial end along the deflection direction 90 of the coupling element 70, a stop element 74 is provided, which positively limits an axial movement of the nut element 52 relative to the coupling element 70. While during a manual opening of the door (Figure B of the Fig. 4 ) the nut element 52 is relatively displaced inside the coupling element 70, it strikes in the case of a force generated by the motor unit 12 of the drive unit 10 (cf. Fig. 1 ) via the threaded spindle 24 driven opening movement on the stop element 74 (Figure C of the Fig. 4 ) and thereby pulls the coupling element 70 and thus the piston element 114 in the deflection direction 90 into its holding position.

[0062] The Fig. 5 The further alternative design of the pull mechanism 14 shown is a modification of the one shown in Fig. 4 In particular, the variant shown in Fig. 5 In the embodiment shown, the torsional strength of the nut element 52 in the coupling element 70 is not achieved by the correspondingly non-circular outer and inner contours of the nut element 52 and the coupling element 70, but by a radial axial offset of a common longitudinal axis of the threaded spindle 24 and the internal thread of the nut element 52 in comparison to a central axis of the coupling element 70. When the threaded spindle 24 rotates, the nut element 52 is supported on the coupling element 70; rotation of the nut element 52 is not possible due to the axial offset. Overall, this means that in this embodiment too, the nut element 52 is held in place by a rotation generated by the motor unit 12 of the drive unit 10 (cf. Fig. 1 ) via the threaded spindle 24 driven opening movement against the stop element 74 of the coupling element 70 (Figure C of the Fig. 5 ) and thereby pulls the coupling element 70 and thus the piston element 114 into its holding position in the deflection direction 90. This variant has proven to be particularly simple and therefore advantageous in manufacturing.

[0063] In contrast to the Fig. 2 bis 5 The embodiments shown are shown in Fig. 6 In the alternative of the pulling mechanism 14 shown, the threaded connection is not provided between the drive shaft 22 and the nut element 52, but between the nut element 52 and the coupling element 70. In these and similar embodiments of the pulling mechanism 14, it is provided that the nut element 52 has a central opening 60 and the drive shaft 22 has a drive section 26, which are adapted to one another for a rotational drive of the nut element 52 by the drive shaft 22. In the exemplary embodiment shown in Fig. 6 In the variant shown, the central opening 60 and the drive section 26 are hexagonal and thus not circular. Furthermore, axial displacement is ensured by the fact that the cross section of the drive section 26 is axially constant. To prevent pulling of the coupling element 70 and thus of the piston element 114 (cf. Fig. 1 ) along the deflection direction 90, the drive shaft 22 has an end stop 34 which projects radially beyond the cross-section as an axial limiting element 32. When the drive shaft 22 rotates, the nut element 52, which also rotates, is supported on this end stop 34, and the coupling element 70 and thus the piston element 114 are pulled along the deflection direction 90 via the threaded connection.

[0064] Another possibility of a central opening 60 of a nut element 52 and a drive section 26 of a drive shaft 22, which are adapted to each other for the rotational driving of the nut element 52 by the drive shaft 22, is shown in Fig. 7 The left image of the Fig. 7 shows the nut element 52. The right-hand illustration shows the drive shaft 22 together with the nut element 52 with an existing drive-effective connection between these elements. The inset illustration A shows an optionally possible way of holding a door in the open state after a manual opening process. In particular, the variant shown can be referred to as a keyhole arrangement. The drive section 26 has a cylindrical central part 28 and a sector part 30 projecting radially therefrom, and the central opening 60 has a cylindrical middle section 62 corresponding to the central part 28 and a sector opening 64 corresponding at least to the size of the sector part 30. Furthermore, a sector cover 66 complementary to the sector opening 64 is provided on the nut element 52 and has a sector cover 66 which is attached to a contact surface 68 driven by the electric motor unit 12 (cf. Fig. 1 ) facing away from the stop 68. As long as the drive section 26 is aligned such that its sector part 30 coincides with the sector opening 64 of the central opening 60, there is no drive-effective connection between the drive shaft 22 and the nut element 52 and thus between the motor unit 12 and the piston element 114. If the drive shaft 22 is driven and rotated in the opening direction, the sector part 30 engages behind the sector aperture 66 and strikes the stop 68. As a result, the rotation of the drive shaft 22 is transferred to the nut element 52. At the same time, the sector part 30 bears against the axial surface of the sector aperture 66, whereby an axial movement of the nut element 52 along the deflection direction 90 is blocked and thus, via the threaded connection between the nut element 52 and the coupling element 70, the piston element 114 is pulled (in Fig. 7 (not shown in each case) in the deflection direction 90. As long as the nut element 52 and the drive shaft 22 do not change their positions relative to one another, the positive engagement of the sector part 30 on the sector cover 66 prevents movement of the nut element 52 and thus of the piston element 114 counter to the deflection direction 90, whereby the door is held in its open position. By aligning both the sector part 30 and the corresponding axial surface of the sector cover 66 perpendicular to the deflection direction 90, it is ensured that this relative positioning of the nut element 52 and the drive shaft 22 remains unchanged even without active drive by the motor unit 12, for example in the event of a power supply failure, which also enables the use of this design variant in a RWA system.

[0065] As shown in the inset Figure A, the drive shaft 22 can additionally have a stop segment 36, which also protrudes radially beyond the central part 28. After a manual opening operation of the door, recognizable in the inset Figure A by the position of the nut element 52 along the drive shaft 22, by a corresponding rotation of the drive shaft 22, the stop segment 36 can engage behind the sector panel 66 and, as described above analogously to the sector part 30, hold the door in its open position.

[0066] The following Fig. 8 bis 11 show two embodiments of a door drive 100 according to the invention, in which the transmission device 20 each has a lifting actuator 40 and engaging elements 46 switchable by the latter for selectively forming and releasing a drive-effective connection between the drive shaft 22 and the nut element 52. Apart from the transmission device 20, the door drive 100 shown essentially correspond to the Fig. 1 shown door drive 100, to the description of which reference is made.

[0067] In the Fig. 8 , 9 the engagement elements 46 are spring-loaded pawls, in the Fig. 10 , 11 designed as a ball lock pin. Fig. 8 , 10 each show a sectional view through the respective door drive 100 according to the invention, Fig. 9 , 11 three detailed views of different states of the respective train mechanism 14. Analogous to the figures A, B, C of the Fig. 2 bis 6 Figure A shows a resting state or initial state with the door closed, Figure B shows a manually driven opening movement of the door and Figure C shows an opening movement of the door caused by the drive unit 10. The Fig. 8 bis 11 are therefore described together below, with differences between the embodiments being discussed separately.

[0068] The lifting actuator 40 is, as shown in the sectional views of the door drive 100 according to the invention in the Fig. 8 , 10 clearly visible, preferably arranged near the electric motor unit 12 and encompassing the drive shaft 22. Furthermore, a lifting rod 44 is provided which is mounted by the drive shaft 22 and can be displaced along the deflection direction 90 by the lifting actuator 40. By displacing the lifting rod 44, the respective engagement elements 46 can be moved between an engagement position (cf. Figure C in Fig. 9 , 11) and a release position (see Figure A, B in Fig. 9 , 11 ) can be activated. In the preferred embodiment shown, the lifting actuator 40 comprises an electromagnet as an electrically controllable drive element for adjusting the lifting rod 44.

[0069] Preferably, as in the Fig. 8 , 10 shown, the lifting actuator 40 further comprises an adjusting spring 42 acting on the lifting rod 44 along the deflection direction 90. This adjusting spring 42 is designed such that it exerts a force on the engagement elements 46 via the lifting rod 44 in the direction of their engagement position (cf. Figure C in Fig. 9 , 11). In this way, it can be ensured that the entire drive unit 10 is maintained in a state in which the drive-effective connection between the drive unit 10 and the piston element 114 is maintained, even in the event of an external power supply failure. This has the particular advantage that after the piston element 114 is pulled into its holding position, it is also securely held in the holding position. Thus, the door remains in its open position even without an external power supply. This is necessary when used in smoke and heat extraction systems as a supply air surface.

[0070] In other words, the lifting actuator 40 is preferably designed such that energizing the electromagnet mentioned as an example pulls the lifting rod 44 against the force of the adjusting spring 42 and thereby moves the engagement elements 46 into their release position (cf. Figures A, B in Fig. 9 , 11) are activated. Without energization of the electromagnet and thus especially in the event of a power failure, only the adjusting spring 42 acts on the lifting rod, so that the engagement elements 46 are moved into their engagement positions (see Figure C in Fig. 9 , 11 ).

[0071] In the release position there is no drive connection between the drive shaft 22 and the nut element 52, see figures A, B in Fig. 9 , 11 . In its engaged position, however, the respective engagement element 46 forms a positive connection with the correspondingly adapted central opening 60 of the nut element 52 both radially and axially, see Figure C in Fig. 9 , 11, so that a rotational movement of the drive shaft 22 initiated by the motor unit 12 is transmitted to the nut element 52, an axial displacement of the nut element 52 along the drive shaft 22 is prevented and thus as a result a pulling of the piston element 114 along the deflection direction 90 by the drive unit 10 is possible.

[0072] In other words, when the engagement elements 46 are in their release position, a movement of the coupling element 70 is decoupled from the nut element 52, and the door can be opened manually without hindrance (see Figures B in Fig. 9 , 11) or by the energy stored in the closing spring 116. However, when the engagement elements 46 are in the engaged position, the threaded connection between the nut element 52 and the coupling element 70 causes a rotation of the drive shaft 22 in the opening direction of rotation to pull the coupling element 10 and thereby the piston element 114 along the deflection direction 90, see Figure C in Fig. 9 , 11 .

[0073] As in the Fig 8 bis 11 As can be seen, in addition to the engagement elements 46, additional holding elements 48 can be provided, which are designed analogously to the respective engagement element 46 and are arranged on the drive shaft 22 along the deflection direction 90 axially offset from these. These holding elements 48 can also be activated by the respective lifting actuator 40. Due to their axial offset, these holding elements 48 can be used to hold the respective door after a manual opening operation (see Figures B in Fig. 9 , 11 ) in the open position. The holding elements 48 are, as shown, preferably designed in particular such that the holding elements 48 can be overrun by the nut element 52 during the manual opening process.

[0074] A further alternative embodiment of the door drive 100 according to the invention, which is particularly equipped with a type of ballpoint pen mechanism, is shown in Fig. 12 , 13 The function of the door drive 100 shown, in particular with regard to the corresponding drive unit 10, essentially corresponds to that already described with regard to Fig. 1 and 4described embodiment, to which reference is made above. The use of the mechanism in the manner of a ballpoint pen mechanism in this embodiment is to be understood as an example, so the type of ballpoint pen mechanism could also be used analogously, for example, in other embodiments of the door drive 100 according to the invention, e.g. according to Fig. 6 be used.

[0075] As already stated above, the Fig. 12 shown door drive 100, in particular its drive unit 10, in addition to the already mentioned with reference to Fig. 1 , 4 The elements described above have a type of ballpoint pen mechanism. This mechanism, in the manner of a ballpoint pen mechanism, is formed in particular by a contoured sleeve 80, which is rotatably mounted around the drive shaft 22 and secured against axial movement along the deflection direction 90, having a guide contour 82 and a guide pin 84 arranged on the coupling element 70 and engaging in the guide contour 82. Fig. 12 shows a sectional view of the door drive 100, in Fig. 13 five different relative positionings of the guide pin 84 in the guide contour 82 are shown.

[0076] In particular, the guide contour 82 is shaped in such a way that after a movement of the coupling element 70, and thus of the guide pin 84, in the deflection direction 90, the coupling element 70 is held in an at least partially deflected position, in particular the holding position, see Figures A, B, C in Fig. 13 . In this case, it is particularly irrelevant whether this movement in the deflection direction 90 is caused manually or by the motor unit 12. Only after renewed movement of the coupling element 70 in the deflection direction 90, by which the guide pin 84 is moved further in the guide contour 82, is a complete return of the guide pin 84 or the coupling element 70 and thus of the piston element 114 to its initial position possible ("push-to-close" principle), see Figures D, E in Fig. 13This type of ballpoint pen mechanism thus makes it possible, in particular, for the coupling element 70 to be held in a deflected position, in particular the holding position, even if an external electrical power supply is completely lost, and the door accordingly remains in its open position. Use of the door drive 100 according to the invention in a smoke and heat extraction system can thus be made even safer, since the door can be opened not only by motor but also manually and remains securely in its open position. List of reference symbols

[0077] 10Drive unit 12Motor unit 14Traction mechanism 16Energy storage 18Control and / or regulation electronics 20Transmission device 22Drive shaft 24Threaded spindle 26Drive section 28Central part 30Sector part 32Limiting element 34End stop 36Stop segment 40Lifting actuator 42Adjusting spring 44Lifting rod 46Engaging element 48Holding element 50Connecting part 52Nut element 54Outer contour 56Bolt 60Central opening 62Middle section 64Sector opening 66Sector cover 68Stop 70Coupling element 72Inner contour 74Stop element 76Groove 78Axial surface 80Contour sleeve 82Guide contour 84Guide pin 90Deflection direction 100 door drive 110Housing 112Drive mechanism 114Piston element 116Closing spring 118Drive shaft

Claims

1. Door drive (100) for a door, having a drive mechanism (112) which is able to be coupled to the door and has a displaceable piston element (114), wherein, in the assembled state of the door drive (100), a movement of the door and a displacement of the piston element (114) are mutually associated, wherein the drive mechanism (112) comprises a drive unit (10) which has an electric motor unit (12) and a traction mechanism (14) that is able to be driven by the electric motor unit (12), wherein a rotational movement of the electric motor unit (12) in an opening rotation direction is convertible into a translational movement of the piston element (114) by the traction mechanism (14), wherein the traction mechanism (14) comprises a transmission device (20) which is able to be rotationally driven by the electric motor unit (12), a coupling element (70) which is connected, in particular integrally, to the piston element (114), and a connecting part (50) which is disposed between the transmission device (20) and the coupling element (70), characterized in that the door drive has a closer spring (116) which impinges the piston element (114) in the closing direction of the door, in that a manual opening movement of the door displaces the piston element (114) proceeding from an initial position, counter to a force of the closer spring (116), in a deflection direction (90) and as a result stores mechanical energy in the closer spring (116) for a closing movement of the door, wherein when activating the electric motor unit (12) in the opening rotation direction, the traction mechanism (14) pulls the piston element (114) from the initial position counter to the force of the closer spring (116) to a holding position in which the drive unit (10) then holds the piston element (114) while the closer spring (116) is tensioned, as a result of which furthermore, in the assembled state of the door drive, the door is held in an open position, and in that the connecting part (50) is co-rotationally coupled to the transmission device (20), in particular so as to be axially displaceable in a limited manner, and to the coupling element (70) by way of a threaded connection, or vice-versa.

2. Door drive (100) according to Claim 1, characterized in that the electric motor unit (12) and / or the traction mechanism (14) are disposed in series with the piston element (114) and / or the closer spring (116) in the direction of deflection (90) of the piston element (114).

3. Door drive (100) according to Claim 1 or 2, characterized in that the traction mechanism (14) is coupled to the piston element (114) in such a manner that a manual opening movement of the door is still possible while the piston element (114) is being pulled by the drive unit (10) from the initial position to the holding position, in particular in that the traction mechanism (14) is coupled, or able to be coupled, to the piston element (114) in a force-transmitting manner only on one side.

4. Door drive (100) according to one of the preceding claims, characterized in that the traction mechanism (14) is designed in such a manner that, when activating the electric motor unit (12) counter to the opening rotation direction, there is no operatively effective connection between the drive unit (10) and the piston element (114), so that the electric motor unit (12) does not transmit any force to the piston element (114).

5. Door drive (100) according to one of the preceding claims, characterized in that the drive unit (10) is designed to be self-locking, wherein preferably the electric motor unit (12) is designed to be self-locking, in particular the electric motor unit (12) is designed as a self-locking gear motor unit (12) with a stepper motor and a planetary gear, and / or the traction mechanism (14) is designed to be self-locking.

6. Door drive (100) according to one of the preceding claims, characterized in that the drive unit (10) comprises an electrical energy accumulator (16) for pulling the piston element (114), counter to the force of the closer spring (116), from the initial position to the holding position at least once.

7. Door drive (100) according to one of the preceding claims, characterized in that the drive unit (10) comprises open-loop and / or closed-loop control electronics (18) for receiving trip signals and based thereon for actuating the electric motor unit (12).

8. Door drive (100) according to one of the preceding claims, characterized in that in the assembled state of the door drive (100), the holding position of the piston element (114) corresponds to an opening angle of the door of between more than 0° and 180°, in particular between 75° and 105°, preferably of 90°.

9. Door drive (100) according to one of the preceding claims, characterized in that the closer spring (116) is designed as a coil spring, and the coupling element (70) and / or the connecting part (50) and / or parts of the transmission device (20) are disposed in the interior of the closer spring (116).

10. Door drive (100) according to one of the preceding claims, characterized in that the coupling element (70) is of a tubular design and / or the transmission device (20) has a drive shaft (22) which in particular plunges into the tubular coupling element (70), and / or the connecting part (50) has a nut element (52).

11. Door drive (100) according to Claim 10, characterized in that the drive shaft (22) is at least in portions formed as a threaded spindle (24), and the nut element (52) by way of an internal thread adapted to the threaded spindle (24) is disposed on the threaded spindle (24) and mounted so as to be co-rotational and axially displaceable in the tubular coupling element (70), wherein in the case of a drive shaft (22) driven in the opening rotation direction, the axial displaceability is limited in such a way that the coupling element (70) and the piston element (114) follow an axial movement of the nut element (52) along the threaded spindle (24), but not in the case of a drive shaft (22) driven counter to the opening rotation direction.

12. Door drive (100) according to Claim 11, characterized in that at least one bolt (56) is disposed radially on the nut element (52), wherein the at least one bolt (56) engages in an axially extending groove (76) in the coupling element (70), wherein furthermore, when the drive shaft (22) is being driven in the opening rotation direction, an axial movement of the nut element (52) relative to the coupling element (70) is delimited by a form-fitting impact of the at least one bolt (56) on an axial face (78) of the groove (76), in particular an axial end of the groove (76) or at least a sub-portion of the groove (76).

13. Door drive (100) according to Claim 11, characterized in that the nut element (52) has a non-circular, in particular hexagonal, external contour (54), wherein the nut element (52) is mounted so as to be co-rotational and axially displaceable in an internal contour (72) of the tubular coupling element (70) that is designed so as to correspond to the external contour (54), wherein furthermore the coupling element (70) is provided with a detent element (74) which, when the drive shaft (22) is being driven in the opening rotation direction, delimits in a form-fitting manner an axial movement of the nut element (52) relative to the coupling element (70).

14. Door drive (100) according to Claim 11, characterized in that a common longitudinal axis of the threaded spindle (24) and of the internal thread is disposed so as to be offset from a central axis of the coupling element (70), wherein the coupling element (70) is provided with a detent element (74) which, when the drive shaft (22) is driven in the opening rotation direction, delimits in a form-fitting manner an axial movement of the nut element (52) relative to the coupling element (70).

15. Door drive (100) according to Claim 10, characterized in that the drive shaft (22) has a drive portion (26) for rotationally driving the nut element (52), wherein the nut element (52) has a continuous central opening (60) which for rotational driving is adapted to the drive portion (26) of the drive shaft (22), wherein the drive shaft (22) by way of its drive portion (26) penetrates the central opening (60), wherein furthermore the nut element (52) has an external thread which engages in an internal thread of the tubular coupling element (70), and the drive shaft (22) has an axial delimitation element (32) which, when the drive shaft (22) is driven in the opening rotation direction, delimits in a form-fitting manner an axial movement of the nut element (52) relative to the drive shaft (22).

16. Door drive (100) according to Claim 15, characterized in that the drive portion (26) has an axially constant, non-circular, in particular hexagonal, cross section, and the central opening (60) is adapted to this cross section of the drive shaft (22), and as a result the nut element (52) is mounted so as to be co-rotational and axially displaceable on the drive shaft (22), wherein the drive shaft (22) has as an axial delimitation element (32) an end stop (34) extending radially beyond the cross section.

17. Door drive (100) according to Claim 15, characterized in that the drive portion (26) has a cylindrical central part (28) and a sector part (30) protruding radially from the latter, and the central opening (60) of the nut element (52) has a cylindrical central portion (62) corresponding to the central part (28), and a sector opening (64) corresponding at least to the size of the sector part (30), wherein the nut element (52) has a sector aperture (66) which is complementary to the sector opening (64) and has a stop (68) that is disposed on a side facing away from the electric motor unit (12), wherein, in the case of a sector part (30) aligned on the sector opening (64), there is no operatively effective connection between the drive unit (10) and the piston element (114) and, in the case of a drive shaft (22) driven in the opening rotation direction, the sector part (30) impacts in a form-fitting manner the stop (68) of the sector aperture (66) and furthermore forms the axial delimitation element (32).

18. Door drive (100) according to Claim 15, characterized in that the transmission device (20) has a lifting actuator (40), a lifting rod (44) which is mounted by the drive shaft (22) and is displaceable along the deflection direction (90) by the lifting actuator (40), and at least one engagement element (46) which is mounted on the drive shaft (22) and is able to be switched by the lifting rod (44) between an engagement position and a release position, wherein the at least one engagement element (46) in its engagement position, by engaging in the correspondingly adapted central opening (60) of the nut element (52), forms the drive portion (26) and the delimitation element (32) of the drive shaft (22).

19. Door drive (100) according to Claim 18, characterized in that the lifting actuator (40) has an actuating spring (42) which acts on the lifting rod (44) along the deflection direction (90), wherein the actuating spring (42) by way of the lifting rod (44) exerts on the at least one engagement element (46) a force acting in the direction of the engagement position of the latter.

20. Door drive (100) according to Claim 18 or 19, characterized in that the at least one engagement element (46) is a pawl or a ball locking bolt.

21. Door drive (100) according to one of the preceding claims, characterized in that the drive unit (10) has a contour sleeve (80) which is mounted so as to be rotatable about the transmission device (20), in particular the drive shaft (22) and is secured in relation to an axial movement along the deflection direction (90) and has a guide contour (82), wherein the coupling element (70) has a guide pin (84) that engages in the guide contour (82), wherein the guide contour (82) conjointly with the guide pin (84) forms a type of ballpoint pen mechanism which, after a movement of the coupling element (70) in the deflection direction (90), holds the coupling element (70) in an at least partially deflected position, in particular the holding position, and upon a renewed movement of the coupling element (70) in the deflection direction (90), enables a complete return of said coupling element to its initial position.