HOLDING DEVICE AND DOOR DRIVE

Description

[0001] The invention relates to a locking device for locking a sliding block of a door drive for automatically closing a door, the sliding block being mounted displaceably in a slide rail. The locking device comprises a locking element with a locking section and an energizable electromagnet. The locking element is movable between a release position and a locking position and, in the assembled state in its locking position, blocks a movement of the sliding block past the locking element, coupled to a closing movement of the door, with the locking section. The electromagnet, in its energized state, locks the locking element in its locking position. Furthermore, the invention relates to a door drive for automatically closing a door, comprising a slide rail and a sliding block mounted displaceably in the slide rail, as well as a locking device for locking the sliding block.

[0002] Common locking devices for sliding blocks in door operators used to automatically close a door, so-called slide rail door closers, feature actuating elements or mechanisms to block the sliding block's closing movement. These mechanisms are often locked by an electromagnet. When used on fire doors, the power supply becomes active in the event of a fire, and passive in the event of a power failure, cut off, and the electromagnet releases the mechanism. This allows the sliding block to pass through the mechanism of the locking device, closing the door.

[0003] The internal design and arrangement of the mechanical actuating elements determine the efficiency and triggering reliability of the respective locking device. In conventional locking devices, a holding force for locking the sliding block is often generated by the mechanism itself, for example, through spring elements. The electromagnet, on the other hand, is used to block movement of the actuating elements, for example, by positively engaging one of the actuating elements.

[0004] Overall, this often results in a complex mechanical design of the holding device, which can increase its susceptibility to errors. Internal friction losses can also occur, which are often not negligible. To ensure high operational reliability of the holding device, which is particularly necessary when used on safety-critical doors such as fire doors, precise manufacturing tolerances must be maintained. The size of the spring elements used to provide the required holding force also complicates the desired compact design of the holding device.

[0005] DE 35 37 177 A1 relates to a locking device for a fire-proof door, comprising a holding device with a locking mechanism and a slide. The locking mechanism has an actuating element pivotally mounted in a housing and provided with a tubular section into which a stop is inserted and biased downwards by a spring whose biasing force is adjustable by a screw screwed into the tubular section. The slide is provided with an inclined surface at the front end and a recess for receiving the stop. The slide is displaceable in the space formed between the actuating element and the housing, with the stop being guided upwards by the inclined surface of the slide. The slide is locked by the stop when it falls into the recess in the slide.The slider is released from the locking mechanism by pivoting the actuating element or by pushing the stop upwards against the preload force of the spring.

[0006] It is therefore an object of the present invention to at least partially remedy the above-described disadvantages of known locking devices and door drives of the prior art. In particular, the object of the present invention is to provide a locking device and a door drive that are mechanically particularly simple and, moreover, particularly compact, and exhibit a low susceptibility to failure and high operational reliability.

[0007] The above object is achieved by the patent claims. In particular, the object is achieved by a locking device having the features of independent claim 1 and by a door drive having the features of claim 12. Further features and advantages of the locking device according to the invention and the door drive according to the invention emerge from the subclaims, the description, and the drawings.

[0008] According to the invention, the object is achieved by a locking device for locking a sliding block of a door drive, which sliding block is mounted displaceably in a slide rail, for automatically closing a door, wherein the locking device has a locking element with a locking section and an energizable electromagnet, wherein the locking element is movable between a release position and a locking position and, in the assembled state in its locking position with the locking section, blocks a movement of the sliding block past the locking element, which movement is coupled to a closing movement of the door, and wherein the electromagnet, in its energized state, locks the locking element in its locking position.The locking device according to the invention further comprises a coupling mechanism, wherein the coupling mechanism comprises a first rocker, a second rocker and a first coupling rod which is rotatably connected to both the first rocker and the second rocker, wherein the first rocker forms the blocking element, wherein a second coupling rod is provided which is rotatably connected to both the second rocker and to a contact end of an armature rod which is displaceable by the electromagnet, and wherein the electromagnet, in its energized state, displaces the armature rod into an active position in which the armature rod locks the blocking element in its blocking position via the second coupling rod and thereby via the coupling mechanism.The locking device according to the invention is characterized in that the first rocker is designed as a two-armed lever with a rotatable bearing about a first bearing point, the locking section at a first end of the lever and a rotatable connection to the first coupling rod at the second end of the lever, and the second rocker is designed as a two-armed lever with a rotatable bearing about a second bearing point, a rotatable connection to the first coupling rod at a first end of the lever and a rotatable connection to the second coupling rod at the second end of the lever.

[0009] The locking device according to the invention is intended for use in door drives for automatically closing doors, particularly in slide rail door closers. For this purpose, the locking device according to the invention can, for example, be arranged in and / or on a slide rail of the door drive, in which the sliding block is slidably guided. Particularly preferably, the locking device according to the invention can ensure the safe operation of such a door drive on fire doors.

[0010] To lock a sliding block of the door drive, the locking device according to the invention has a locking element that can be locked in a locked position by an electromagnet. In this locked position, the locking element prevents movement of the sliding block past the locking element via a locking section. Since a movement of the door is coupled with a movement of the sliding block, the door is thereby held in an open position. For this locking function, the locking section can preferably, for example, protrude into a travel path of the sliding block in the slide rail.

[0011] If the electromagnet's power supply is removed, for example, by actively switching off the power supply or due to a power outage, as can often occur in the event of a fire, the locking element's locking position is released, allowing the sliding block to pass the holding device and continue its movement in the closing direction. As a result, the door closes.

[0012] Essential to the invention, the locking device according to the invention comprises a coupling mechanism. The coupling mechanism is used, in particular, for the direct transmission or translation of a magnetic force generated by the electromagnet into a holding force with which the locking element blocks the movement of the sliding block.

[0013] The essential components of the coupling mechanism include a first and a second rocker arm, each of which is rotatably mounted in the locking device, for example, in a housing of the locking device. Both rockers are coupled to each other by a first coupling rod, which is rotatably connected to both rockers. In other words, the movements of the individual elements of the coupling mechanism are firmly correlated with each other. All elements of the coupling mechanism are always moving; if one of the elements is blocked in its movement, the entire coupling mechanism is blocked.

[0014] According to the invention, the first rocker forms the locking element. Thus, the first rocker also has the locking section and can be moved into the locking position, in which the locking section can lock the sliding block. At the same time, a second coupling rod is also provided, which is rotatably connected to the second rocker and to a contact end of an anchor rod.

[0015] This armature rod, in turn, can be moved by the electromagnet. Specifically, the armature rod is moved into an active position when the electromagnet is energized. The electromagnet then holds the armature rod in this active position; in other words, the armature rod is fixed in the active position when the electromagnet is energized. This movement of the armature rod is transmitted to the second rocker and thus to the entire coupling mechanism via the second contact rod.

[0016] In its active position, as described above, the armature rod is held by the electromagnet and thereby prevents any movement of the second rocker, in particular in the direction of the armature rod. The entire coupling mechanism is constructed in such a way that the position assumed by the first rocker and thus by the locking element corresponds to the locking position. In this way, in the locking device according to the invention, the locking element is locked in its locking position by the electromagnet via the coupling mechanism. The holding force transmitted to the sliding block by the locking element is essentially based on the magnetic force generated by the electromagnet, which is transmitted and translated by the coupling mechanism. Preferably, it can be provided that the coupling mechanism translates the magnetic force into a comparatively greater holding force.This allows, for example, smaller electromagnets to be used and thus the locking device according to the invention can be made more compact overall.

[0017] According to the invention, both rockers are designed as two-armed levers. The effective lever arms of the first rocker extend from the first bearing point to the locking section or to the location of the rotatable mounting of the first coupling rod on the first rocker. The effective lever arms of the second rocker extend analogously from the second bearing point to the location of the rotatable mounting of the first coupling rod or the second coupling rod on the second rocker. The shape of the first or second rocker can follow the respective effective lever arms or deviate from them. Two-armed levers are mechanically particularly simple components. Simply by selecting the length of the respective effective lever arms, a transmission ratio of the entire coupling mechanism can be set particularly easily.

[0018] In summary, the coupling mechanism described above represents a mechanically very simple system that also requires very little installation space. Complex designs, including, for example, mechanical energy storage devices such as spring elements for generating the holding force or precisely coordinated element sections for enabling positive engagement to lock the locking element in its locking position, can be avoided. The simplicity of the design also reduces the susceptibility to errors, thereby increasing the operational reliability of the locking device according to the invention.

[0019] Furthermore, the locking device according to the invention can be further developed such that the first rocker arm and / or the second rocker arm are angled, with a first leg and a second leg that are firmly connected to one another at an apex, wherein the rotatable bearing of the respective rocker arm is arranged at the apex. An angled design of the respective rocker arm can be described by the smaller angle that the two legs enclose at the apex. The legs each enclose this angle with their inner sides, while the respective outer sides of the legs enclose the larger complementary angle. The position of the respective two-armed lever in the locking device is determined by the arrangement of the respective rotatable bearing, around the first bearing point in the first rocker arm and analogously around the second bearing point in the second rocker arm.Together with the angle described above and the lengths of the individual effective lever arms already specified, the transmission ratio of the entire coupling gear can be influenced in a particularly simple manner.

[0020] According to a further development, the locking device according to the invention can also be characterized in that the second bearing point is arranged in the direction of movement of the armature rod between the first bearing point and the electromagnet. In other words, starting from the electromagnet, the second rocker arm and then the first rocker arm are arranged in the locking device. Since the second rocker arm is connected to the armature rod via the second coupling rod and to the first rocker arm via the first coupling rod, the two coupling rods are also arranged at least substantially one after the other along the direction of movement of the armature rod. This results in a sequential arrangement of the elements of the coupling mechanism along the direction of movement of the armature rod. In this way, a particularly flat design with correspondingly low installation space requirements can be achieved, particularly transversely to this direction of movement.

[0021] Alternatively, the locking device according to the invention can also be further developed such that the first bearing point is arranged between the second bearing point and the electromagnet in the direction of movement of the armature rod. In other words, starting from the electromagnet, the first rocker arm and then the second rocker arm are arranged in the locking device. Since the second rocker arm is connected to the armature rod via the second coupling rod and to the first rocker arm via the first coupling rod, the two coupling rods are arranged at least substantially side by side along the direction of movement of the armature rod. This results in a particularly compact arrangement of the elements of the coupling mechanism, which results in a correspondingly small installation space requirement.

[0022] The locking device according to the invention can also be designed such that the locking device has a return spring for pre-tensioning the locking element in the direction of its locking position, wherein the return spring acts on at least one of the following elements: first swing arm, second swing arm, first coupling rod, second coupling rod anchor rod.

[0023] This list is not exhaustive, so the return spring can also act at other technically feasible locations. Such a return spring makes it particularly easy to ensure that, for example, after the sliding block has passed the position of the locking section during an opening movement of the door, the locking device according to the invention with the locking element is already set in its locking position. To lock the sliding block, all that is required is to energize the electromagnet, which preferably occurs automatically, in particular via appropriate contact switches and / or contactless trigger switches.

[0024] Furthermore, in the locking device according to the invention, it can be provided that the electromagnet comprises a magnetic coil with a continuous, preferably central, coil opening, wherein the armature rod engages in the coil opening and / or passes through the coil opening, and wherein the armature rod is preferably displaceably mounted in the coil opening. Magnetic coils represent a particularly simple type of electromagnet. By engaging or passing through the coil opening of the magnetic coil with the armature rod, the magnetic force generated by the electromagnet can be transmitted to the armature rod in a particularly effective and, at the same time, space-saving manner. If the armature rod is simultaneously mounted in the coil opening, further additional mounting devices for the armature rod can be dispensed with.

[0025] Preferably, the locking device according to the invention can furthermore be provided with an armature plate arranged on the armature rod, wherein the electromagnet attracts the armature plate when energized, so that the armature plate strikes the electromagnet. The armature plate preferably extends perpendicular to the longitudinal extent of the armature rod. Furthermore, a diameter of the armature plate is preferably designed to be adapted to the size of the electromagnet; in particular, for example, the diameter of the armature plate essentially corresponds to that of the magnetic coil. Overall, the armature plate can optimize force transmission from the electromagnet to the armature rod. It can even be provided that only the armature plate consists of a material that is magnetically attracted, and the armature rod itself consists of a non-magnetic material.

[0026] The locking device according to the invention can also be further developed such that the armature rod extends through the coil opening, and the armature plate and the contact end are arranged at opposite ends of the armature rod for exerting a pressing force on the coupling mechanism when the electromagnet is energized. As described above, the force is transmitted from the electromagnet to the coupling mechanism via the second coupling rod and its rotatable connection to both the armature rod and the second rocker. This can be achieved particularly easily and reliably by providing, for example, a pressing force by the energized electromagnet. The armature plate is attracted to the electromagnet on one side. Since the armature rod extends through the solenoid coil, the armature rod on the other side of the electromagnet is automatically extended and presses on the second rocker via the second coupling rod.

[0027] Alternatively, the locking device according to the invention can also be characterized in that the armature rod at least engages in the coil opening, and the armature plate and the contact end are arranged on the same side of the armature rod with respect to the electromagnet for exerting a pulling force on the coupling mechanism when the electromagnet is energized. As described above, the second coupling rod provides the force transmission from the electromagnet to the coupling mechanism. This can be achieved particularly easily and reliably when a pulling force, for example, is provided by the energized electromagnet. The armature plate is attracted to one side of the electromagnet.Since the armature plate and the contact end of the armature rod are arranged on the same side with respect to the electromagnet on the armature rod, the armature rod is automatically retracted into the coil opening and pulls via the second coupling rod on the second rocker.

[0028] Furthermore, the locking device according to the invention can be characterized in that the electromagnet, in its energized state, applies a magnetic force of between 50 N and 100 N to the armature rod in the direction of the active position. Such electromagnets are inexpensive to purchase and, in particular, require a particularly small amount of space. For example, electromagnets with a coil diameter of less than 20 mm can be used, which enables a particularly compact design of the entire locking device according to the invention.

[0029] According to a further embodiment, the locking device according to the invention can further be provided with a coupling gear having a transmission ratio of 10 or greater, with which it translates a magnetic force of the electromagnet into a holding force with which the locking element blocks the movement of the sliding block. In order to block a closing movement of the sliding block of known door drives, a holding force of 500 to over 1000 N must often be applied by the locking element. With a transmission ratio of 10 or greater, which is provided by the coupling gear, a significantly smaller magnetic force, for example 50 to 100 N, is sufficient to securely lock the sliding block. The required electromagnet can thus be smaller and the entire locking device according to the invention can be designed more compact.

[0030] According to a second aspect of the invention, the object is achieved by a door drive for automatically closing a door, according to claim 12, comprising a slide rail and a sliding block displaceably mounted in the slide rail, as well as a locking device for locking the sliding block. The door drive according to the invention is characterized in that the locking device is designed according to the first aspect of the invention. All the advantages described above with regard to a locking device according to the first aspect of the invention can thus also be provided by a door drive according to the second aspect of the invention, which has the locking device according to the first aspect of the invention.

[0031] Furthermore, the door drive according to the invention can be designed such that the slide rail has, preferably encloses, a receiving section in which the locking device is arranged. In particular, if the receiving section is enclosed by the slide rail, the locking device can be arranged entirely within the slide rail. Overall, this allows the locking device to be integrated particularly easily into the door drive according to the invention.

[0032] Furthermore, the door drive according to the invention can be further developed such that the slide rail is designed as a profile component with two receiving planes, wherein one of the receiving planes forms the receiving section for the locking device, and the sliding block is displaceably mounted in the other of the receiving planes. A profile component is characterized in particular in that the receiving planes have an at least substantially constant free cross-section along a longitudinal extent of the profile component. Thus, the locking device can be arranged at different positions along the longitudinal extent of the slide rail in one of the receiving planes of the profile component, whereby the closing movement of the sliding block can be blocked in the other receiving plane accordingly, likewise at different positions.Since a position of the sliding block is firmly linked to an opening position of the door, it is possible to keep the door open at different opening angles.

[0033] 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.

[0034] They show schematically: Fig. 1 shows a part of a door drive according to the invention in a sectional view, Fig. 2 shows a simplified side view of a first embodiment of the locking device according to the invention with the locking element in the locking position, Fig. 3 shows a side view of the locking device of Fig. 2 , Fig. 4 a side view of the locking device of Fig. 2 with the locking element outside the locking position, Fig. 5 a simplified side view of a second embodiment of the locking device according to the invention, Fig. 6 a simplified side view of a third embodiment of the locking device according to the invention, and Fig. 7 a simplified side view of a fourth embodiment of the locking device according to the invention.

[0035] In Fig. 1 A sectional view of a slide rail 110 of a door drive 100 according to the invention is shown. In the illustrated embodiment, the slide rail 110 is designed as a profile component with two receiving planes 114, 116. A sliding block 80 of the door drive 100 according to the invention is displaceably mounted in the lower receiving plane 116, with a displacement direction corresponding to the longitudinal extent of the slide rail 110 being oriented perpendicular to the plane of the drawing. The second, upper receiving plane 114 forms a receiving space 112 in which the locking device 10 according to the invention is arranged. Also shown is a locking section 16 of a locking element 14 of the locking device 10, which projects into the travel path of the sliding block 80 and thereby blocks it.

[0036] In the Fig. 2 bis 4 a first embodiment of a door drive 100 according to the invention with a locking device 10 according to the invention is shown, wherein only the sliding block 80 of the door drive 100 is shown. Fig. 2 shows a simplified representation of only the relevant elements of the locking device 10, Fig. 3 and 4 show an actually possible constructive realization of the locking device 10. In the following, the Fig. 2 bis 4 described together, with the differences between the illustrations being discussed.

[0037] In particular, in the Fig. 2 bis 4 two different states of the door drive 100 are shown. In the Fig. 2 and 3 the locking element 14 is in its locking position, whereby a closing movement 82 of the sliding block 80 is blocked. In Fig. 4 In contrast, the locking element 14 is deflected from its locking position into its release position, the sliding block 80 is freely movable, both for a closing movement 82 and for an opening movement 84.

[0038] As in Fig. 2 , 3 As shown, the sliding block 80 can be locked by the locking portion 16 of the locking element 14, thereby preventing a closing movement 82 of the sliding block 80. As a result, the door connected to the sliding block 80 is held open. A return spring 12 (only in Fig. 2 shown) ensures that, for example, after passing over the locking section 16 with a switched-off electromagnet 60, which is explained in more detail below, after deflection of the locking element 14 into its release position during an opening movement 84 of the sliding block 80 (see Fig. 4 ), the locking element 14 is again in the Fig. 2 , 3As shown in the example in Fig. 3 , 4 As shown, this automatic setting of the locking position can be used together with a switching element 74, which can register a passage of the sliding block 80, in order to activate a current supply to the electromagnet 60 after the sliding block 80 has passed the locking element 14 during an opening movement 84 and thereby also to lock the locking element 14 in the locking position.

[0039] An essential element of the locking device 10 according to the invention is a coupling gear 20, which translates a magnetic force 72 of the electromagnet 60 into a holding force 18, with which the closing movement 82 of the sliding block 80 is blocked. The coupling gear 20 shown has a transmission ratio of 10 or greater, so that even simple and, in particular, small or compact electromagnets 60 with a maximum magnetic force 72 between 50 and 100 N can be used.

[0040] The coupling mechanism 20 comprises a first rocker arm 30 rotatable about a first bearing point 32, a second rocker arm 36 rotatable about a second bearing point 38, and a first coupling rod 42, which is rotatably connected to each of the two rockers 30, 36. The first rocker arm 30 forms, in particular, the locking element 14 with the locking section 16 already described above. Furthermore, a second coupling rod 44 is provided, which connects the second rocker arm 36 to a contact end 66 of an armature rod 64 displaceable by the electromagnet 60.

[0041] Both rockers 30, 36 are designed as two-armed levers. The effective lever arms of the two rockers 30, 36 extend from the respective bearing point 32, 38 to the mechanically determining points of the rockers 30, 36, namely, in the case of the first rocker 30, to the locking section 16 and the location of the rotatable connection with the first coupling rod 42, and in the case of the second rocker, to the corresponding locations of the rotatable connection with the first coupling rod 42 and the second coupling rod 44, respectively. The actual shape of the two rockers 30, 36 can be based on the effective lever arms, but can also be designed differently from them, as long as it encompasses the respective ends of the lever arms.

[0042] In addition, both wings 30, 36 are angled with a first leg 52 and a second leg 54, which are firmly connected to each other at a vertex 50 (legs 52, 54 only in Fig. 2 The apex point 50 is identical to the corresponding bearing point 32, 38, the two legs 52, 54 correspond to the effective lever arms described above.

[0043] To lock the locking element 14 in its locking position (see Fig. 2 , 3 ) the electromagnet 60 is energized. As a result, an armature plate 68, which is arranged on the armature rod 64, is attracted by the electromagnet 60. Overall, the armature rod 64 is moved along its direction of movement 70 by the electromagnet 60 into the Fig. 2 , 3shown active position. In particular, the armature rod 64 passes through a central coil opening 62 of a magnetic coil of the electromagnet 60, wherein, as shown, the armature rod 64 is preferably also mounted in the coil opening 62, so that the contact end 66 of the armature rod 64 exerts a pressing force on the second coupling rod 44 and thus on the entire coupling gear 20. Since the armature plate 68 is held in place by the magnetic force 72, movement of all elements of the coupling gear 20, namely both rockers 30, 36 and the first coupling rod 42, is also blocked, thereby locking the locking element 14 in its locking position.

[0044] The overall design of the coupling mechanism 20, in particular a position of the bearing points 32, 38, directions of rotation 34, 40 of the rockers 30, 36, a length of the distances between the bearing points 32, 38 and the rotatable connections to the coupling rods 42, 44, or the position of the locking section, is selected such that the above-mentioned transmission ratio of greater than 10 can be enabled. This is sufficient for the closing forces that occur with the commonly used locking mechanisms of the door drives 10 to block the automatic closing of the door.

[0045] In the Fig. 2 bis 4 In the illustrated embodiment of the locking device 10 according to the invention, the first bearing point 32 of the first rocker arm 30 is arranged between the electromagnet 60 and the second bearing point 38 of the second rocker arm 36 in the direction of movement 70 of the armature rod 64. The two coupling rods 42, 44 are thus arranged at least substantially adjacent to one another with respect to the aforementioned direction of movement 70. This enables an overall particularly compact arrangement of the elements of the coupling mechanism 20 with a correspondingly low installation space requirement.

[0046] As in Fig. 4 As shown, when the current supply to the electromagnet 60 is cut off, whether actively by switching off the power supply or passively by, for example, a power failure in the event of a fire, the locking of the blocking element 14 ends and the sliding block 80 can simply push the blocking section 16 away. Without the holding magnetic force 72 (in Fig. 4 not shown), the deflection of the locking element 14, i.e. the first rocker 30, via the remaining coupling gear 20 and the second coupling rod 44 leads to a corresponding displacement of the armature rod 64 and finally to a lifting of the armature plate 68 from the electromagnet 60. To simplify the deflection of the locking element 14, the sliding block 80 and / or the locking section 16 can have a correspondingly designed run-on slope. In addition, if it is desired to close the door with the locking element 14 locked and the door thus held open, the locking element 16 can also be pushed over by manually applying force to the door and thus indirectly to the sliding block 80. In this case, a force so high that the armature plate 68 is lifted from the electromagnet 60.

[0047] The Fig. 5 bis 7 show various alternative embodiments of the locking device 10 according to the invention, each in a simplified side view. To avoid repetition, the following particularly describes the differences to the locking device 10 shown in Fig. 2 bis 4 shown embodiment is described and otherwise reference is made to the above description of the Fig. 2 bis 4 All essential features and advantages, in particular the particularly simple and compact mechanism of the locking device 10, its low susceptibility to errors, and high operational reliability, are made possible by all described embodiments of the locking device 10 according to the invention or the door drive 100 according to the invention.

[0048] Fig. 5 shows a locking device 10 in which, analogous to the one in Fig. 2 bis 4 In the embodiment shown, the first bearing point 32 is arranged between the electromagnet 60 and the second bearing point 38 with respect to the direction of movement 70 of the armature rod 64. In particular, the above-described advantages of a particularly space-saving design of the coupling gear 20 can thus also be achieved by the Fig. 5 shown embodiment of the locking device 10 according to the invention.

[0049] In contrast to the design of the Fig. 2 bis 4 However, the coupling mechanism 20 is now subjected to a pulling force by the electromagnet 60. For this purpose, as shown in Fig. 5 As shown, the armature plate 68 and the contact end 66 are arranged on the same side of the armature rod 64 with respect to the electromagnet 60. When the electromagnet 60 is energized, the armature plate 68 is attracted by the electromagnet 60, thereby exerting a pulling force on the coupling mechanism 20. Fig. 5 The corresponding design of the locking device 10 shown, in particular the positions of the bearing points 32, 38, angles between the legs 52, 54 of the rockers 30, 36, directions of rotation 34, 40 of the rockers 30, 36, lengths of the distances between the bearing points 32, 38 and the rotatable connections to the coupling rods 42, 44 or the position of the locking section 16, is selected such that this pulling force also leads to a secure locking of the locking element 14 in its locking position.

[0050] The two Fig. 6 , 7 show locking devices 10 according to the invention, which differ from those shown in Fig. 2 bis 5 shown variants of locking devices 10 in particular in that here the second bearing point 38 is arranged between the electromagnet 60 and the first bearing point 32 with respect to the direction of movement 70 of the armature rod 64. Due to the associated corresponding arrangement of the two rockers 30, 36, namely starting from the electromagnet 60 first the second rocker 36 and then the first rocker 30, the two coupling rods 42, 44 are also arranged at least substantially one after the other along the direction of movement 70 of the armature rod 64. As shown in the Fig. 6 , 7 As can be seen, this enables a flat design transverse to the direction of movement 70 with a correspondingly low installation space requirement for the coupling gear 20 and thus for the entire locking device 10.

[0051] Even in the embodiments of the locking device 10 according to the invention described in the previous paragraph, the respective coupling gear 20 can be actuated both with a pressing force (cf. Fig. 6 ), as well as with a pulling force (cf. Fig. 7 ) As already mentioned with reference to the Fig. 2 bis 4 or 5, in addition to the correspondingly adapted mechanics of the coupling gear 20, a position of the arrangement of the armature plate 68 on the armature rod 64 is decisive, for example for a pulling force with respect to the electromagnet 60 on the same side of the armature rod 64 as its contact end 66 (see Fig. 7 ). For a pressing force, however, as already mentioned with reference to Fig. 2 bis 4 described, an arrangement of the armature plate 68 and the contact end 66 with respect to the electromagnet 60 on different sides of the armature rod 64 is required (in Fig. 6 but not shown). List of reference symbols

[0052] 10Locking device 12Return spring 14Locking element 16Locking section 18Holding force 20Coupling gear 30First swing arm 32First bearing point 34First direction of rotation 36Second swing arm 38Second bearing point 40Second direction of rotation 42First coupling rod 44Second coupling rod 50Vertex 52First leg 54Second leg 60Electromagnet 62Coil opening 64Armature rod 66Contact end 68Armature plate 70Direction of movement 72Magnetic force 74Switching element 80Sliding block 82Closing movement 84Opening movement 100 door drive 110Slide rail 112Receiving section 114Receiving plane 116Receiving plane

Claims

1. Fixing device (10) for fixing a sliding block (80), which is displaceably mounted in a slide rail (110), of a door drive (100) for automatically closing a door, wherein the fixing device (10) has a blocking element (14) having a blocking portion (16) and an energizeable solenoid (60), wherein the blocking element (14) is movable between a releasing position and a blocking position and in the assembled state in its blocking position by way of the blocking portion (16) blocks a movement of the sliding block (80), which is coupled to a closing movement (82) of the door, past the blocking element (14), and wherein the solenoid (60) in its energized state arrests the blocking element (14) in its blocking position, wherein the fixing device (10) has a coupling gear (20), wherein the coupling gear (20) comprises a first swing arm (30), a second swing arm (36) and a first coupling rod (42) which is rotatably coupled to the first swing arm (30) as well as to the second swing arm (36), wherein the first swing arm (30) forms the blocking element (14), wherein a second coupling rod is provided (44) which is rotatably connected to the second swing arm (36) as well as to a contacting end (66) of an armature rod (64) which is displaceable by the solenoid (60), and wherein the solenoid (60) in its energized state displaces the armature rod (64) to an active position in which the armature rod (64) by way of the second coupling rod (44), and as a result by way of the coupling gear (20), arrests the blocking element (14) in its blocking position, characterized in that the first swing arm (30) is formed as a dual-arm lever having a mounting rotatable about a first bearing point (32), the blocking portion (16) formed on a first end of the lever, and a rotatable connection to the first coupling rod (42) on the second end of the lever, and the second swing arm (36) is formed as a dual-arm lever having a mounting rotatable about a second bearing pint (38), a rotatable connection to the first coupling rod (42) on a first end of the lever, and a rotatable connection to the second coupling rod (44) on the second end of the lever.

2. Fixing device (10) according to Claim 1, characterized in that the first swing arm (30) and / or the second swing arm (36) are formed at an angle, having a first leg (52) and a second leg (54) which are fixedly connected to one another at a vertex (50), wherein the rotatable mounting of the respective swing arm (30, 36) is disposed on the vertex (50).

3. Fixing device (10) according to Claim 1 or 2, characterized in that the second bearing point (38) is disposed in the direction of movement (70) of the armature rod (64) between the first bearing point (32) and the solenoid (60).

4. Fixing device (10) according to Claim 1 or 2, characterized in that the first bearing point (32) is disposed in the direction of movement (70) of the armature rod (64) between the second bearing point (38) and the solenoid (60).

5. Fixing device (10) according to one of the preceding claims, characterized in that the fixing device (10) has a restoring spring (12) for preloading the blocking element (14) in the direction of its blocking position, wherein the restoring spring (12) engages on at least one of the following elements: - first swing arm (30), - second swing arm (36), - first coupling rod (42), - second coupling rod (44), - armature rod (64).

6. Fixing device (10) according to one of the preceding claims, characterized in that the solenoid (60) comprises a solenoid coil having a continuous, preferably central, coil opening (62), wherein the armature rod (64) engages in the coil opening (62) and / or penetrates the coil opening (62), and wherein the armature rod (64) is preferably displaceably mounted in the coil opening (62).

7. Fixing device (10) according to Claim 6, characterized in that an armature plate (68) is disposed on the armature rod (64), wherein the solenoid (60) in the energized state attracts the armature plate (68) so that the armature plate (68) strikes the solenoid (60).

8. Fixing device (10) according to Claim 7, characterized in that the armature rod (64) penetrates the coil opening (62), and the armature plate (68) and the contacting end (66) are disposed on opposite ends of the armature rod (64) for exerting a pressing force on the coupling gear (20) in the energized state of the solenoid (60).

9. Fixing device (10) according to Claim 7, characterized in that the armature rod (64) at least engages in the coil opening (62), and the armature plate (68) and the contacting end (66) in terms of the solenoid (60) are disposed on the same side of the armature rod (64) for exerting a pulling force on the coupling gear (20) in the energized state of the solenoid (60).

10. Fixing device (10) according to one of the preceding claims, characterized in that the solenoid (60) in its energized state impinges the armature rod (64) with a magnetic force (72) between 50 N and 100 N in the direction of the active position.

11. Fixing device (10) according to one of the preceding claims, characterized in that the coupling gear (20) has a gear ratio of 10 or more, by way of which it converts a magnetic force (72) of the solenoid (60) into a holding force (18) by way of which the blocking element (14) blocks the movement of the sliding block (80).

12. Door drive (100) for automatically closing a door, having a slide rail (110) and a sliding bock (80) which is displaceably mounted in the slide rail (110), and a fixing device (10) for fixing the sliding block (80), characterized in that the fixing device (10) is designed according to any one of the preceding claims.

13. Door drive (100) according to Claim 12, characterized in that the slide rail (110) has, preferably encloses, a receptacle portion (112) in which the fixing device (10) is disposed.

14. Door drive (100) according to Claim 13, characterized in that the slide rail (110) is formed as a profile component having two receptacle planes (114, 116), wherein one of the receptacle planes (114, 116) forms the receptacle portion (112) for the fixing device (10), and the sliding block (80) is displaceably mounted in the other one of the receptacle planes (114, 116).