Patent Publication Number: US-11641912-B2

Title: Closure device with closure parts which can be placed against each other

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. patent application Ser. No. 17/277,345, filed Mar. 18, 2021, which is the United States national phase of International Application No. PCT/EP2019/074855 filed Sep. 17, 2019, and claims priority to German Patent Application No. 10 2018 123 026.5 filed Sep. 19, 2018, the disclosures of which are hereby incorporated by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     This disclosure relates to a closure device. 
     Description of Related Art 
     Such a closure device comprises a first closure part which includes a base body and at least one closure element rotatably arranged on the base body around an axis of rotation. The at least one closure element comprises a base body and at least one first locking portion arranged on the base body. At least one second closure part includes a base element and at least one second locking portion arranged on the base element. The first closure part and the at least one second closure part can be placed against each other along a placement direction such that in a closed position the at least one locking portion of the at least one closure element and the locking portion of the at least one second closure part are in engagement with each other and the closure parts thus are attached to each other. To release the first closure part and the at least one second closure part from each other, the at least one closure part can be rotated relative to the base body of the first closure part so as to bring the at least one first locking portion of the at least one closure element and the at least one second locking portion of the at least one second closure part out of engagement with each other. 
     In closures for fastening a belt for example for a child seat or a perambulator, on the one hand an easy handling in particular for closing the closure device with a firm, loadable hold in the closed position is desirable. Here, care should be taken in particular that in use on a child seat in a vehicle under particular circumstances, for example in the event of a crash, high load forces may act, which must not cause the locking device to open. 
     It is also desirable to allow such closure device to be operated in a simple way also for opening. 
     In a closure device known from WO 2014/090926 A1 a first closure part and a second closure part can be placed against each other and in a closed position are positively in engagement with each other via engaging protrusions. Magnetic means act between the closure parts so that on placement the closure parts are drawn into engagement with each other and the closure parts are held against each other in the closed position. 
     SUMMARY OF THE INVENTION 
     An object underlying the proposed solution is to provide a closure device which is to be closed easily and comfortably, but also is to be opened again, with a high loadability in particular for use on a child seat or perambulator or also on a helmet, in particular a sports helmet such as a ski helmet or a bicycle helmet. 
     This object is achieved by a closure device with features as described herein. 
     Accordingly, the closure device includes an actuating element adjustably arranged on the base body, which is operatively connected to the at least one closure element in such a way that by adjusting the actuating element relative to the base body, the at least one closure element is rotatable relative to the base body. 
     Thus, the closure element on the base body of the first closure part can be actuated via an actuating element. The actuating element can be shifted or rotated with respect to the base body by a user in order to transmit an adjusting force to the closure element and to adjust the same relative to the base body in particular for opening the closure device so that with its first locking portion the closure element gets out of engagement with the second locking portion of the second closure part, and the first closure part and the second closure part thus can be released from each other. 
     The closure device in particular can include a plurality of closure elements rotatably arranged on the base body, against each of which a second (identically constructed) closure part can be placed. Such a configuration of the closure device may be advantageous in particular for use for example on a belt system for example for a child seat in a vehicle in order to thereby create a multipoint attachment. On each second closure part a belt can be arranged so that by attaching the second closure parts to the first closure part a plurality of belts can be fixed relative to the first closure part. There is obtained an easy handling in particular for closing the closure device. 
     When a plurality of closure elements are provided on the base body for attaching a plurality of second closure parts to the first closure part, the actuating element advantageously cooperates with all closure elements at the same time so that the closure elements can jointly be actuated by the actuating element in particular for opening the closure device. The actuating element can be operatively connected to all closure elements separately. It is, however, also conceivable and possible that the actuating element acts on one of the closure elements, which in turn is coupled to another closure element so that adjusting forces are introduced from the actuating element into a closure element and from the one closure element into the other closure elements. 
     The actuating element can be designed in different ways. For example, the actuating element can include a coupling portion via which the actuating element is positively or non-positively operatively connected to the at least one closure element. The actuating element can be designed for example as a rod element, as a wheel element, as a cable element, as a chain, as a force-deflecting slope or as a coulisse element. It is likewise conceivable to design the actuating element as a pushbutton which can be actuated by pressing, wherein the pressing movement can be converted into a rotary movement of the closure element via a suitable force deflection, for example a helical toothing. 
     In one embodiment, the actuating element is configured as a toothed rack or as a gear wheel. Correspondingly, the actuating element includes a toothing which cooperates with an associated counter-toothing of the closure element and thus drives the closure element. When the actuating element is configured as a toothed rack, for example, the actuating element preferably is linearly shiftable relative to the base body. When the actuating element is configured as a gear wheel (for example as a ring gear with an internal toothing), the actuating element is rotationally twistable relative to the base body. 
     Instead of a positive coupling with an associated closure element via a toothing, it is also conceivable to non-positively couple the actuating element with the closure element, for example by a frictional connection in which a friction surface of the actuating element cooperates with an associated friction surface of the closure element. 
     In one embodiment, the at least one locking portion is rigidly arranged on the base body of the at least one closure element. Likewise, the at least one second locking portion is rigidly arranged on the base element of the at least one second closure part. The at least one first locking portion and the at least one second locking portion hence are each configured rigid and substantially inelastic, and thus form rigid undercuts. On placement of the second closure part against an associated closure element of the first closure part, the locking portions are positively brought into engagement with each other so that a connection between the second closure part and the associated closure element of the first closure part is produced. 
     The closure device, however, can also employ another connecting technique, in which in particular one of the locking portions can be configured elastically resilient. In particular, the closure device can be configured in the form of a closure, as it is described in EP 2 040 572 B1, EP 2 166 895 B1, WO 2014/090926 A1, EP 3 019 757 A2, EP 3 116 747 B1 or EP 2 271 233 B1. 
     Such a closure device can include one or more closure elements on the first closure part so that one or more second closure parts can be placed against the first closure part. 
     In one embodiment, the at least one first locking portion protrudes from the base body of the closure element along the axis of rotation, and the at least one second locking portion likewise can protrude from the base element of the second closure part along the axis of rotation. When the second closure part is placed against an associated closure element of the first closure part, the locking portions come into engagement with each other and thus produce a connection between the second closure part and the first closure part so that in the closed position the second closure part is firmly and loadably held at the first closure part. 
     In one embodiment, the at least one first locking portion includes a first latching protrusion and the at least one second locking portion includes a second latching protrusion. The first latching protrusion and the second latching protrusion, which realize (in particular rigidly configured) undercuts, are positively in engagement with each other in the closed position and thus produce the connection between the second closure part and the closure element of the first closure part. 
     For example, run-up slopes can be formed on the latching protrusions so that on placement of the second closure part against the closure element of the first closure part, the latching protrusions can run up onto each other and thus be moved past each other until the latching protrusions come into engagement with each other in the closed position. 
     In one embodiment, the closure element includes two (or more) first locking portions arranged on the base body, which are arranged on different sides of the axis of rotation and for example face each other diametrically to the axis of rotation. The second closure part correspondingly includes two (or more) second locking portions which in the closed position are positively in engagement with the first locking portions of the closure element so that a connection between the second closure part and the closure element is produced via several pairs of locking portions. 
     On each first locking portion a first latching protrusion can be arranged, and on each second locking portion correspondingly a second latching protrusion. One of the first latching protrusions preferably points radially to the inside, whereas the other one of the first latching protrusions points radially to the outside, which allows the second latching protrusions of the second closure part to be brought into engagement with the first latching protrusions on the closure element in a common engagement direction transversely to the axis of rotation, in order to positively connect the second closure part to the closure element in the closed position. 
     For opening the closure device, the closure element preferably is rotatable relative to the second closure part by an angle greater than 90°, for example by up to 180° or even more than 180°. The first locking portions of the closure element and the second locking portions of the second closure part are shaped and arranged correspondingly, so that when the closure element is rotated relative to the second closure part, the locking portions do not impede a twisting movement between the closure element and the second closure part. 
     For example, the latching protrusions of the first locking portions of the closure element can be arranged on different radii (with respect to the axis of rotation) so that a positive connection between the first locking portions and the second locking portions is produced at different radial positions. 
     In one embodiment, the at least one second closure part includes a blocking element with a blocking portion, which serves to secure the connection of the second closure part to the associated closure element in the closed position. Correspondingly, in the closed position of the closure device the blocking portion is arranged on a side of the at least one first locking portion of the closure element facing away from the at least one second locking portion and thus blocks the engagement between the first locking portion and the associated second locking portion. The first locking portion and the second locking portion thus cannot come out of engagement with each other due to a transverse movement transversely to the axis of rotation, but are positively held in engagement with each other via the blocking portion. 
     In the closed position, the blocking portion in particular can be arranged radially inside the at least one locking portion. On the one hand, this provides for a reliable blockage, because forces acting transversely to the axis of rotation between the second closure part and the closure element act on the blocking portion with an unfavorable lever arm and thus cannot lead to an (unwanted) displacement of the blocking portion. In addition, the blocking portion comes to lie outside such a space, which is swept over by the locking portions on twisting of the closure element so that the blocking element with its blocking portion does not impede a rotary movement of the closure element, in particular for opening the closure device. 
     The blocking element, in one embodiment, is displaceable relative to the base element of at least one second closure part. For example, the blocking element can be elastically pretensioned relative to the base element along the axis of rotation, for example via a suitable spring element or by action of a magnetic force between the blocking element and the base element, which pretensions the blocking element in the direction of a blocking position for blocking the engagement between the locking portions. 
     The blocking element can be received in a receiving space of the second closure part for example with a head portion and can be displaceable in the receiving space. With its blocking portion the blocking element protrudes into the area of the locking portions so that via the blocking portion the positive connection between the locking portions can be secured when the closure device is in its closed position. 
     In one embodiment, the at least one closure element has a first side and a second side. On the first side and on the second side at least one first locking portion each is arranged, wherein one second closure part each can be placed against the first side and against the second side. Thus, two second closure parts can be placed against the closure element on different, preferably mutually opposite sides so that the closure element can be connected to a plurality of second closure parts. By rotating the closure element relative to the base body of the first closure part, the second closure parts can be released from the closure element at the same time so that a constructionally simple, easy-to-use closure device is obtained. 
     The second closure part to be placed against the first side and the second closure part to be placed against the second side here can be identical in construction so that closure parts of the same type can be placed against the different sides of the closure element. 
     The closure device can be of purely mechanical design and provide for a placement of the at least one second closure part against an associated closure element of the first closure part. In an advantageous embodiment, the closure device however is configured as a magneto-mechanical closure device in which the placement of the at least one second closure part against the first closure part is supported in a magnetic way. 
     For this purpose, the at least one closure element of the first closure part includes at least one first magnetic element and the at least one second closure part includes at least one second magnetic element, wherein the at least one first magnetic element and the at least one second magnetic element are configured to cooperate in a magnetically attracting manner when the first closure part and the at least one second closure part are placed against each other, so that the placement is supported in a magnetic way. Thus, the second closure part is magnetically drawn into engagement with the associated closure element and thus gets in connection with the closure element. 
     When the closure element is twisted for opening the closure device, the at least one first magnetic element of the closure element and the at least one second magnetic element of the second closure part can be displaced relative to each other in such a way that the force of magnetic attraction is attenuated or even converted into a repulsion. For example, the closure element and the second closure part each can include two magnetic elements, formed by permanent magnets, which are reversed in polarity with respect to each other when the closure element is rotated to open the closure device, so that a force of magnetic attraction is reversed into a magnetic repulsion. In this way, the opening of the closure device can be supported in a magnetic way. 
     The first closure part, in one embodiment, includes resetting means for resetting the actuating element back into a starting position associated with the closed position. Such resetting means for example can be formed by a spring which has a pretensioning effect between the base body and the actuating element. However, such resetting means for example can also act magnetically. 
     The object also is achieved by a closure device comprising a first closure part which includes a closure element with a base body and at least one first locking portion arranged on the base body, and a second closure part, which includes a base element and at least one second locking portion arranged on the base element. The first closure part and the second closure part can be placed against each other along a placement direction. In a closed position, the first closure part and the second closure part are placed against each other in such way that the at least one first locking portion of the closure element and the at least one second locking portion of the second closure part are in engagement with each other. To release the first closure part and the second closure part from each other, the at least one first locking portion of the closure element and the at least one second locking portion of the second closure part can be brought out of engagement with each other by rotating the closure element about an axis of rotation relative to the second closure part. It is provided that the second closure part includes a blocking element with a blocking portion which in the closed position is arranged radially inside the at least one first locking portion with respect to the axis of rotation and blocks the engagement of the at least one first locking portion and the at least one second locking portion with each other. 
     By providing the blocking element, the first locking portion and the second locking portion thus cannot come out of engagement with each other due to a transverse movement transversely to the axis of rotation, but are positively held in engagement with each other by means of the blocking portion. 
     Due to the fact that in the closed position the blocking portion is arranged radially inside the at least one locking portion, this on the one hand provides for a reliable blockage, because forces acting transversely to the axis of rotation between the second closure part and the closure element act on the blocking portion with an unfavorable lever arm and thus cannot lead to an (unwanted) displacement of the blocking portion. In addition, the blocking portion comes to lie outside such a space which is swept over by the locking portions on twisting of the closure element so that the blocking element with its blocking portion does not impede a rotary movement of the closure element, in particular for opening the closure device. 
     The blocking element, in one embodiment, is adjustable relative to the base element of at least one second closure part. For example, the blocking element can be elastically pretensioned relative to the base element along the axis of rotation, for example via a suitable spring element or by action of a magnetic force between the blocking element and the base element, which pretensions the blocking element in the direction of a blocking position for blocking the engagement between the locking portions. 
     The blocking element can be received in a receiving space of the second closure part for example with a head portion and can be displaceable in the receiving space. With its blocking portion, the blocking element protrudes into the area of the locking portions so that via the blocking portion the positive connection between the locking portions can be secured when the closure device is in its closed position. 
     In one embodiment, the closure element includes two (or more) first locking portions arranged on the base body, which are arranged on different sides of the axis of rotation and for example face each other diametrically to the axis of rotation. The second closure part correspondingly includes two (or more) second locking portions which in the closed position are positively in engagement with the first locking portions of the closure element so that a connection between the second closure part and the closure element is produced via several pairs of locking portions. 
     On each first locking portion a first latching protrusion can be arranged, and on each second locking portion correspondingly a second latching protrusion. One of the first latching protrusions preferably points radially to the inside, whereas the other one of the first latching protrusions points radially to the outside, which allows the second latching protrusions of the second closure part to be brought into engagement with the first latching protrusions on the closure element in a common engagement direction transversely to the axis of rotation, in order to positively lock the second closure part with the closure element in the closed position. 
     For opening the closure device, the closure element preferably is rotatable relative to the second closure part by an angle greater than 90°, for example by up to 180° or even more than 180°. The first locking portions of the closure element and the second locking portions of the second closure part are shaped and arranged correspondingly, so that when the closure element is rotated relative to the second closure part, the locking portions do not impede a twisting movement between the closure element and the second closure part. 
     For example, the latching protrusions of the first locking portions of the closure element can be arranged on different radii (with respect to the axis of rotation) so that a positive connection between the first locking portions and the second locking portions is produced at different radial positions. 
     The closure element, in one embodiment, can form the first closure part so that the closure device has a two-part design and to open the closure device, the closure element as a whole is rotatable relative to the second closure part. It is, however, also conceivable and possible to provide the first closure part with a three-part design, comprising a base body on which the closure element is rotatably arranged about the axis of rotation. On the base body, for example, a belt attachment can be mounted for fastening a belt, wherein with a stationary base body the closure element is rotatable relative to the second closure part in order to open the closure device. 
     Advantageously, the closure device is configured as a magneto-mechanical closure device. For this purpose, the closure element of the first closure part includes at least one first magnetic element and the second closure part includes at least one second magnetic element, wherein the at least one first magnetic element and the at least one second magnetic element are configured to cooperate in a magnetically attracting manner when the first closure part and the second closure part are placed against each other, so that the placement is supported in a magnetic way. Thus, the second closure part is magnetically drawn into engagement with the associated closure element and thus gets into connection with the closure element. 
     When the closure element is twisted for opening the closure device, the at least one first magnetic element of the closure element and the at least one second magnetic element of the second closure part can be displaced relative to each other in such a way that the force of magnetic attraction is attenuated or even reversed into a repulsion. For example, the closure element and the second closure part each can include two magnetic elements, formed by permanent magnets, which are reversed in polarity with respect to each other when the closure element is twisted to open the closure device, so that a force of magnetic attraction is reversed into a magnetic repulsion. In this way, however, opening of the closure device can be supported in a magnetic way. 
     The object also is achieved by a closure device comprising a first closure part which includes a closure element with a base body and at least one first locking portion arranged on the base body, and a second closure part which includes a base element and at least one second locking portion arranged on the base element. The first closure part and the second closure part can be placed against each other along a placement direction. In a closed position, the first closure part and the second closure part are placed against each other in such way that the at least one first locking portion of the closure element and the at least one second locking portion of the second closure part are in engagement with each other. To release the first closure part and the second closure part from each other, the at least one first locking portion of the closure element and the at least one second locking portion of the second closure part can be brought out of engagement with each other by rotating the closure element about an axis of rotation relative to the second closure part. It is provided that the closure element has a first side and a second side, wherein on the first side and on the second side at least one first locking portion each is arranged, wherein one second closure part each can be placed against the first side and against the second side. 
     Thus, two second closure parts can be placed against the closure element on different, preferably mutually opposite sides so that the closure element can be connected to a plurality of second closure parts. By rotating the closure element relative to the base body of the first closure part, the second closure parts can be released from the closure element at the same time so that a constructionally simple, easy-to-use closure device is obtained. 
     The second closure part to be placed against the first side and the second closure part to be placed against the second side here can be identical in construction so that closure parts of the same type can be placed against the different sides of the closure element. 
     A closure device of the type described above can be used as a closure for connecting two or more parts to each other. In particular, a closure device as described above can be used as a belt buckle for example for a seat, in particular for a child seat in a vehicle or for a perambulator in order to connect one or more belt portions to a belt buckle. 
     A closure device as described above can also be used for example as a closure for a helmet, in particular for a sports helmet, for example a ski helmet or a bicycle helmet. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The idea underlying the proposed solution will be explained in detail below with reference to the exemplary embodiments illustrated in the Figures. 
         FIG.  1    shows a view of an exemplary embodiment of a closure device which includes a first closure part with a plurality of closure elements rotatably arranged on a base body and a plurality of second closure parts, in an open position; 
         FIG.  2    shows a view of the closure device, in a closed position; 
         FIG.  3    shows an exploded view of the closure device; 
         FIG.  4    shows a view of another exemplary embodiment of closure device, in an open position; 
         FIG.  5    shows a view of the closure device as shown in  FIG.  4   , in a closed position; 
         FIG.  6    shows an exploded view of the closure device as shown in  FIGS.  4  and  5   ; 
         FIG.  7    shows a top view of a second closure part arranged on a closure element of a first closure part; 
         FIG.  8 A  shows a sectional view along line A-A of  FIG.  7    on placement of two closure parts of the closure device against each other; 
         FIG.  8 B  shows a sectional view of the closure device along line A-A of  FIG.  7   , in a closed position; 
         FIG.  8 C  shows a sectional view of the closure device along line A-A of  FIG.  7    on opening of the closure device; 
         FIG.  9    shows a top view of an arrangement in which two second closure parts are placed against a closure element of a first closure part; 
         FIG.  10    shows a sectional view along line B-B of  FIG.  9   ; 
         FIG.  11 A  shows a view of an exemplary embodiment of a closure device, in a closed position; 
         FIG.  11 B  shows a sectional view longitudinally through the closure device as shown in  FIG.  11 A ; 
         FIG.  12 A  shows a view of the closure device on opening; 
         FIG.  12 B  shows a sectional view through the closure device as shown in  FIG.  12 A ; 
         FIG.  13    shows a view of the closure device with closure parts separated from each other; 
         FIG.  14 A  shows a view of a closure device, in a closed position; 
         FIG.  14 B  shows a sectional view through the closure device as shown in  FIG.  14 A ; 
         FIG.  15 A  shows a view of the closure device on opening; 
         FIG.  15 B  shows a sectional view through the closure device as shown in  FIG.  15 A ; and 
         FIG.  16    shows a view of the closure device with closure parts separated from each other. 
     
    
    
     DESCRIPTION OF THE INVENTION 
       FIGS.  1  to  3    show an exemplary embodiment of a closure device  1  which includes a first closure part  2  with a plurality of closure elements  22  arranged on a base body  20  and a plurality of second closure parts  3  to be placed against the closure elements  22  of the first closure part  2  along a placement direction A. In a closed position shown in  FIG.  2   , the second closure parts  3  are connected to the closure elements  22  and thereby held on the first closure part  2 . 
     On the base body  20  of the first closure part  2  a belt attachment  21  is arranged, via which a belt  4  (schematically indicated in  FIG.  2   ) can be attached to the first closure part  2 . In addition, each second closure part  3  includes a belt attachment  31  via which a belt  4  can respectively be attached to each second closure part  3 . In the closed position of the closure device  1 , a multipoint attachment thereby is created, by means of which a plurality of belts  4  are connected to each other. 
     Such a closure device for example can be used as a belt buckle in a child seat in a vehicle or in a perambulator. 
     The closure elements  22  of the first closure part  2  each are rotatably arranged on the base body  20  of the first closure part  2  about an axis of rotation D. Each closure element  2  includes a base body  220  and a locking portion  222  molded thereto and protruding from the base body  220  along the axis of rotation D, which serves to positively come into engagement with an associated locking portion  302  of a second closure part  3 . 
     In the closed position, the locking portion  222  of each closure element  22  is positively in engagement with a radially inwardly pointing latching protrusion on the locking portion  302  of an associated second closure part  3  via a radially outwardly pointing latching protrusion molded thereto. As is shown in  FIG.  2   , the closure parts  3  in this way each are positively connected to a closure element  22  and thereby held on the first closure part  2 . 
     The locking portion  302  in the exemplary embodiment of  FIGS.  1  to  3    is functionally identical with the locking portion  302  of the exemplary embodiment of  FIGS.  4  to  10    described below, so that in this respect reference is made to the following explanations, in particular to the explanations of  FIGS.  8 A to  8 C . 
     The closure elements  22  each include a magnetic device  23  with two magnetic elements  230 ,  231  preferably formed by permanent magnets. As can be taken from the exploded views of  FIG.  3   , each second closure part  3  also includes a magnetic device  33  with two magnetic elements  330 ,  331  preferably formed by permanent magnets, which on placement of the second closure parts  3  against the first closure part  2  cooperate with the magnetic elements  230 ,  231  of the closure elements  22  and thus support the placement of the second closure parts  3  by a force of magnetic attraction. 
     Due to the magnetic effect, in particular the locking portions  222 ,  302  of the closure elements  22  and of the second closure parts  3  are positively drawn into engagement with each other so that in the closed position the second closure parts  3  are securely and reliably locked into place at the first closure part  2  by means of the closure elements  22 . 
     As can be taken from the exploded views of  FIG.  3   , the base body  20  includes bearing openings  200 , in each of which a closure element  22  is rotatably mounted about an associated axis of rotation D. The closure elements  22  here each include a circumferential, radially outwardly protruding toothing  221  on their base body  220 , which is in engagement with an internal toothing  242  on a collar  241  of an actuating element  24  configured as a ring gear. Via a shaft  243  protruding from a body  240  of the actuating element  24 , the actuating element  24  is rotatably mounted on a central bearing opening  201  on the base body  20  of the first closure part  2  so that the actuating element  24  can be rotated relative to the base body  20  of the first closure part  2  along an actuating direction B. 
     Via resetting means, for example a spring acting between an associated closure element  22  and the base body  20 , the closure elements  22  can be resettable into their starting position associated to the closed position. Via resetting means, the actuating element  24  additionally or alternatively can be reset in the direction of its starting position associated to the closed position. 
     By means of the actuating element  24 , the closure elements  22  can be jointly actuated to open the closure device  1 . By rotating the actuating element  24  along the actuating direction B, the closure elements  22  each are rotated relative to the base body  20  about their axis of rotation D along an actuating direction B 1 , due to the meshing engagement of the toothing  242  of the actuating element  24  with the toothings  221  of the closure elements  22 , so that each locking portion  222  on the base body  220  is rotated out of engagement with the associated locking portion  302  of the respective second closure part  3 , and the second closure parts  3  thus can be removed from the first closure part  2  against the placement direction A. 
     By rotating the closure elements  22  (by approximately 180°), the magnetic elements  230 ,  231 ,  330 ,  331  also are reversed in polarity relative to each other, so that the force of magnetic attraction is reversed into a force of magnetic repulsion so that with twisted closure elements  22  the second closure parts  3  are repelled from the first closure part  2  against the placement direction A and thus are automatically separated from the first closure part  2 . 
     The magnetic elements  230 ,  231  of a respective closure element  22  with unlike poles (N, S) point towards an associated second closure part  3 . Likewise, the magnetic elements  330 ,  331  of the second closure part  3  with unlike poles (S, N) point towards the associated closure element  22 , wherein on placement the magnetic elements  230 ,  231 ,  330 ,  331  are arranged relative to each other such that the magnetic elements  230 ,  231 ,  330 ,  331  attract each other. By twisting the respective closure element  22  to open the closure device  1 , the magnetic elements  230 ,  231 ,  330 ,  331  however are moved towards each other so that the magnetic elements  230 ,  231  on the part of the closure element  22  now with like poles come to face the magnetic elements  330 ,  331  on the part of the associated second closure part  3 , and thus a magnetic repulsion exists between the second closure part  3  and the closure element  22 . 
     By means of the closure device  1  a plurality of second closure parts  3  can be placed against a first closure part  2  in a simple, comfortable way in order to create a multipoint attachment. The closure device  1  is loadable and reliably holds the second closure parts  3  on the first closure part  2  also under load. 
     Each second closure part  3  includes a blocking element  32  received in a receiving space  300  of the base element  30  of the second closure part  3 , which blocking element includes a head portion  320  resting in the receiving space  300  and a blocking portion  321  axially protruding from the head portion  320 . The blocking element  32  serves for blocking the engagement of the locking portions  222 ,  302  with each other in the closed position, as this will yet be explained below with reference to the further exemplary embodiments. 
     In another exemplary embodiment illustrated in  FIGS.  4  to  6   , second closure parts  3  are to be placed against closure elements  22  of a first closure part  2 , wherein in this exemplary embodiment each closure element  22  includes two locking portions  222 A,  223 A,  222 B,  223 B on different sides, and thus, the second closure elements  3  can be placed against a closure element  22  from different sides. In the closed position shown in  FIG.  5   , two second closure parts  3  are held on each side of the first closure part  2  so that again a multipoint attachment is created. 
     A belt  4  here is arranged on a belt attachment  21  on a base body  20  of the first closure part  2 . Moreover, each second closure part  3  includes a belt attachment  31  on a base element  30 , via which a belt  4  is fixed to the respective second closure part  3 , as this is schematically indicated in  FIG.  5   . 
     In the exemplary embodiment shown in  FIGS.  4  to  6   , two locking portions  222 A,  223 A,  222 B,  223 B facing each other diametrically to an axis of rotation D (about which the closure element  22  is rotatably mounted on the base body  20  of the first closure part  2 ) are arranged on each side of a closure element  22 , which can each be positively brought into engagement with two locking portions  302 ,  303  on associated second closure parts  3 . 
     As can be taken from the exploded views of  FIG.  6   , each second closure part  3  includes a blocking element  32  which with a head portion  320  is received in a receiving space  300  of the base element  30  of the respectively associated second closure part  3  and with a blocking portion  321  protrudes into the area of the locking portions  302 ,  303  on the base element  30  of the second closure part  3 . The receiving space  300  is closed towards the outside by a lid element  301 . 
     The mode of operation of the closure device  1  for placing, holding and releasing a second closure element  3  on an associated closure element  22  of the first closure part  2  will be explained below with reference to  FIGS.  7  and  8 A to  8 C .  FIGS.  7  and  8 A,  8 B,  8 C  show a second closure element  3  on an associated closure element  22 , which is rotatably mounted on the base body  20  of the first closure part  2  about an axis of rotation D. 
     On the closure element  22  two magnetic elements  230 ,  231  are arranged, which on placement of the second closure part  3  against the closure element  22  cooperate with magnetic elements  330 ,  331  on the base element  30  of the second closure part  3  in a magnetically attracting way ( FIGS.  8 A to  8 C  show the magnetic elements  230 ,  231 ,  330 ,  331  in a sectional representation; as can be taken from a synopsis of  FIG.  9    with  FIG.  10   , the magnetic elements  230 ,  231 ,  330 ,  331  each have a cylindrical shape and, on placement of a second closure part  3  against an associated closure element  22 , face each other with unlike poles in such a way that a force of magnetic attraction exists between the second closure part  3  and the closure element  22 ). 
     On placement of the second closure part  3  against the closure element  22 , the locking portions  302 ,  303  with latching protrusions  304  molded thereto get in contact with the locking portions  222 A,  223 A on the associated side of the closure element  33  and with run-up slopes  305  run up onto the run-up slope  225  on the locking portions  222 A,  223 A of the closure element  22  so that the locking portions  302 ,  303  are moved past the locking portions  222 A,  223 A of the closure element  22  with an offset transversely to the direction of rotation D (against an engagement direction E). The blocking portion  321  of the blocking element  32  on the second closure part  3  thereby gets in contact with the locking portion  222 A of the closure element  22  in the placement direction A and is displaced with respect to the base element  30  by the locking portion  222 A, against a force of magnetic attraction between the blocking element  32  and the base element  30  due to an interaction between a magnetic element  322  on the head portion  320  of the blocking element  32  (formed for example by a magnetic armature made of a ferromagnetic material) and the magnetic elements  330 ,  331  on the base element  30 . 
     Due to the magnetic action between the magnetic elements  230 ,  231 ,  330 ,  331  on the closure element  22  on the one hand and the base element  30  of the second closure part  3  on the other hand, the locking portions  222 A,  223 A,  302 ,  303  then are drawn into engagement with each other in the engagement direction E so that the second closure part  3  reaches the closed position shown in  FIG.  8 B , and the second closure part  3  thus is positively held on the closure element  22 , as is shown in  FIG.  8 B . 
     In the closed position, the blocking portion  321  of the blocking element  32  comes to lie on a radially inner side of the locking portion  222 A of the closure element  22  facing away from the locking portion  302 , as is shown in  FIG.  8 B . The blocking portion  321  thus secures the engagement between the locking portions  222 A,  302  and thereby also the engagement between the locking portions  223 A,  303  on the other side. In particular, the second closure part  3  cannot be offset from the adjusting element  22  against the engagement direction E, and the positive connection between the locking portions  222 A,  223 A,  302 ,  303  can be eliminated. 
     When the closure device  1  is to be opened and the second closure part  3  is to be released from the closure element  22 , the closure element  22  can be rotated by approximately 180° about the axis of rotation D along an actuating direction B 1  so that, as shown in  FIG.  8 C , the locking portions  222 A,  223 A,  302 ,  303  get out of engagement with each other, and the positive connection between the second closure part  3  and the closure element  22  therefore is eliminated. 
     By twisting the closure element  22 , the magnetic elements  230 ,  231 ,  330 ,  331  also are rotated relative to each other such that the magnetic elements  230 ,  231 ,  330 ,  331  now face each other in pairs with like poles, so that the magnetic elements  230 ,  231 ,  330 ,  331  magnetically repel each other and the release of the second closure part  3  from the closure element  22  therefore is magnetically supported. 
     As can be taken from  FIGS.  9  and  10   , a second closure part  3  respectively can be placed against each side of the closure element  22 . The second closure parts  3  are identical in construction, and the positive connection is produced in the same way for each second closure part  3  and can also be released again in the same way. 
     In the exemplary embodiment shown in  FIGS.  4  to  6   , the first closure part  2  includes an actuating element  24  which is configured as a toothed rack and is shiftable relative to the base body  20  of the first closure part  2  along an actuating direction B. The actuating element  24  is received in a guide recess  202  of the base body  20  and is guided in the guide recess  202  along the actuating direction B. Supporting elements  245  extend into spring seats  203  on both sides of the guide recess  202  and act on spring elements  244  in the form of compression springs received in the spring seats  203 , via which the actuating element  24  is pretensioned by spring force relative to the base body  20  in the direction of a starting position associated to the closed position, which is shown in  FIG.  5   , against the actuating direction B. 
     The actuating element  24  in the form of a toothed rack includes two toothings  242  on mutually opposite sides, which each are in coupling engagement with one of the closure elements  22 . Each closure element  22  therefor includes a coupling portion  221  in the form of a circumferential toothing, via which the actuating element  24  meshes with the respective closure element  22  so that on actuation of the actuating element  24  in the actuating direction B, the closure elements  22  are jointly rotated relative to the base body  20  of the first closure part  2  along an actuating direction B 1 , B 2 . The closure elements  22  thereby are adjusted relative to the respectively associated second closure parts  3  so that the form fit between the closure elements  22  and the second closure parts  3  is eliminated and the second closure parts  3  thus can be removed from the first closure part  2  for opening the closure device  1 . 
     Due to the fact that in the closed position the blocking portion  321  of the blocking element  32  comes to lie radially inside the associated blocking portion  222 A of the closure element  22 , an advantageous behavior is obtained with loaded closure parts  2 ,  3  such that the locking portions  222 A,  302  are kept in engagement by the blocking portion  321  and even a clearance between the locking portions  222 A,  302  cannot lead to an opening of the closure device  1  under the influence of loading forces. 
     Due to the fact that second closure parts  3  can be placed against different sides of a closure element  22 , magnetic elements  230 ,  231  in the form of permanent magnets on the closure element  22  can also cooperate with the closure parts  3  on different sides in the same way. The connection of the second closure parts  3  to the closure element  22  on opposite sides thereof thus provides for a simple configuration to provide a multipoint attachment while reducing the number of components of the closure device  1 , and in addition with an easy handling in particular for opening the closure device  1 . 
     The arrangement as shown in  FIGS.  7  and  8 A to  8 C  also can realize a closure device  1  as such with (exactly) one closure element  22 , against which two second closure parts  3  can be placed. 
     While the exemplary embodiments of  FIGS.  1  to  10    realize closure devices  1  in which a plurality of second closure parts  3  are to be placed against a first closure part  2 , it is also possible that in other exemplary embodiments of a closure device  1  merely one first closure part  2  and one second closure part  3  can be connected to each other. 
     In an exemplary embodiment shown in  FIGS.  11 A,  11 B to  13   , the closure device  1  includes a first closure part  2  and a second closure part  3  to be placed against the same, which in their mode of operation for placing the second closure part  3  against the first closure part  2  and for releasing the closure parts  2 ,  3  from each other are identical with the exemplary embodiment of  FIGS.  7  and  8 A to  8 C  so that in particular with regard to the mode of operation of the locking portions  222 ,  223 ,  302 ,  303  and of the blocking element  32  of the second closure part  3  reference will fully be made to the preceding explanations. 
     In the exemplary embodiment shown in  FIGS.  11 A,  11 B to  13   , the closure element  22  of the first closure part  2  is formed integrally with a belt attachment  21 . The closure parts  2 ,  3  can be rotated relative to each other for opening, as this is illustrated in the transition from  FIGS.  11 A,  11 B  to  FIGS.  12 A,  12 B . Thus, there is created a two-part closure device  1  with a first closure part  2  and a second closure part  3 . 
     In an exemplary embodiment shown in  FIGS.  14 A,  14 B to  16   , the closure element  22  of the first closure part  2  on the other hand is rotatably arranged on a base body  20 , which also comprises a belt attachment  21 , and with a stationary base body  20  can be rotated relative to the base body  20  about an axis of rotation D in order to open the closure device  1 , as this is shown in the transition from  FIGS.  14 A,  14 B  towards  FIGS.  15 A,  15 B . When opening the closure device  1 , the belt attachments  21 ,  31  of the first closure part  2  and of the second closure part  3  thus can remain in position relative to each other. 
     Otherwise, the mode of operation of the closure device  1  in particular for producing the positive connection on placement and for releasing is identical, as described above in particular with reference to  FIGS.  7  and  8 A to  8 C . In particular with regard to the mode of operation of the locking portions  222 ,  223 ,  302 ,  303  and the blocking element  32  of the second closure part  3 , reference therefore is made to the above explanations. 
     The idea underlying the solution is not limited to the exemplary embodiments described above, but can also be realized in principle in a completely different way. 
     A closure device as described above can be used as a belt buckle in a child seat for use in a vehicle or also as a belt buckle for perambulator. In particular such exemplary embodiments in which a plurality of second closure parts are to be connected to a first closure part can be used as multipoint attachments in multipoint belt systems. 
     However, such a closure device can also create a connection between two individual closure parts. Such a closure device can be used for example as a buckle in a helmet, for example a sports helmet, for example a ski helmet or a bicycle helmet. Such a closure device can, however, also be used for connecting entirely different assemblies to each other, for example as a closure for a bag, for example a school bag, or for attaching other parts to each other. 
     An actuating element for actuating a closure element of the first closure part or for jointly actuating a plurality of closure elements of the first closure part, as described, can be configured as a gear wheel or toothed rack. However, other actuating elements are also conceivable, for example in the form of a chain, a cable, a pushbutton, a connecting rod or a coulisse element, wherein a force deflection takes place to convert an actuating movement into a rotary movement of one or more closure elements. 
     LIST OF REFERENCE NUMERALS 
     
         
           1  closure device 
           2  first closure part 
           20  base body 
           200 ,  201  bearing opening 
           202  guideway 
           203  spring receptacle 
           21  belt attachment 
           22  closure element 
           220  base body 
           221  coupling portion (toothing) 
           222  locking portion 
           222 A,  222 B locking portion 
           223 A,  223 B locking portion 
           224  latching protrusion 
           225  run-up slope 
           23  magnetic device 
           230 ,  231  magnetic element 
           24  actuating element 
           240  body 
           241  collar 
           242  coupling portion (toothing) 
           243  shaft 
           244  spring element 
           245  supporting element 
           3  second closure part 
           30  base element 
           300  receiving space 
           301  lid element 
           302  locking portion 
           303  locking portion 
           304  latching protrusion 
           305  run-up slope 
           31  belt attachment 
           32  blocking element 
           320  head portion 
           321  blocking portion 
           322  magnetic element 
           33  magnetic device 
           330 ,  331  magnetic element 
           4  belt 
         A placement direction 
         B actuating direction 
         B 1 , B 2  direction of rotation 
         D axis of rotation 
         E engagement direction