Slide chain drive and slide-out arrangement for vehicles, and magnetic resonance imaging apparatus comprising such a slide chain drive

Abstract

Slide-out arrangements for a vehicle allow a slide-out box to be extended in order to enlarge a vehicle interior. The invention relates to a slide-out arrangement comprising: a vehicle-side assembly for attachment to the chassis of the vehicle; a slide-out-side assembly for attachment to a slide-out box; and also a drive system by means of which the vehicle-side assembly and the slide-out-side assembly can be moved relative to one another. According to the invention, the drive system comprises a push-pull chain drive having at least one double chain set, which has at least two chain strands which are supplied independently of one another to a contact region during the extension of the double chain set and which are each unidirectionally bendable chain strands. The at least two chain strands, when said chain strands are extended, come into contact with each other in the contact region in such a way that, supporting or holding each other, they can be extended together as a combined chain unit.

Description

[0001] Sliding chain drive and slide-out arrangement for vehicles and magnetic resonance imaging devices with such a sliding chain drive

[0002] FIELD OF APPLICATION AND STATE OF THE ART

[0003] The invention relates to a push-chain drive and the use of such a push-chain drive in various fields of application, in particular in the field of slide-out systems, i.e. in the field of extensions for the interior of a vehicle with a slide-out box which is positioned in a slide-out recess of a vehicle wall and can be moved between a retracted storage end position and an extended useful end position with an enlarged interior space.

[0004] Rigid chain drives are designed to move assemblies bidirectionally against each other using rigid chains. Compared to pull chains alone, they are specially designed and equipped with special guides to accomplish this task without the rigid chain breaking out of the desired chain path and thus no longer being able to transmit thrust.

[0005] Push-chain drives are already known from the prior art. These are designed with a double chain set and have two independently fed chain strands that are continuously brought together in a contact area during each extension and are extended together as a chain assembly from the contact area. One such design is shown, for example, in document US 8069954 B2.

[0006] What is not yet ideal with known systems is that, depending on the structural environment, they are not easy to integrate in terms of their installation space and there is still room for improvement with regard to the connection that the chain strands form to form a chain network.

[0007] TASK AND SOLUTION

[0008] The object of the invention is to provide a rigid chain drive that overcomes the disadvantages of the prior art and, in particular, allows flexible application even in limited installation space. To solve this problem, a rigid chain drive with at least one double chain set is proposed, in which the double chain set has at least two chain strands that are fed independently of one another to a contact area when the double chain set is extended. When the chain strands are extended, the at least two chain strands come into contact with one another in the contact area in such a way that they support or hold one another and can be extended as a common chain assembly in a main extension direction.

[0009] Independent feeding of the chain strands means that they are fed to the contact area from different directions. The feeding can be carried out by means of separate drives, but preferably by means of a common drive, which particularly preferably acts on the chain assembly in the contact area or beyond the contact area. The ends of the chain strands opposite the chain assembly are arranged in chain stores, in which they are stored in a linearly extended or preferably spirally wound form.

[0010] Preferably, the at least two chain strands of the linear chain drive are each designed as unidirectionally articulated chain strands. A unidirectionally articulated chain strand is understood to be a chain strand that, starting from a linearly aligned extension, only allows bending in one direction due to the shape of its chain links, but at least largely prevents bending in the opposite direction. If the chain is subjected to a force in this blocked direction, the chain links come into contact with each other, limiting movement and preventing buckling in this blocked direction.Preferably, the unidirectional bending mobility is achieved in that an outer contour on two opposite edges of a chain link is rounded on the one hand and is designed without rounding on the other hand, so that buckling of the following chain link is only possible in the area of ​​the rounded outer contour.

[0011] The at least two chain strands are preferably permanently joined at their ends to form a chain assembly. As the chain strands extend, they continuously come into contact with one another in the contact area, supporting or holding each other as they extend to form an extending chain assembly. The bending mobility of the chain links is eliminated within the chain assembly. In the case of unidirectionally bendable chain strands, the bending mobility of both chain strands differs from one another, so that the chain assembly is deprived of mobility transverse to the extension direction. In particular, the at least two chain strands are designed to form a positive coupling in the contact area with respect to a securing direction extending orthogonally to the main extension direction, as explained below.

[0012] The special feature of the proposed rigid chain drive according to the invention is that the at least two chain strands are fed in different chain planes. This means that the two chain strands are not fed in a common plane from different directions within this plane, but rather in different planes. This can be advantageous with regard to the available installation space. In particular, this makes it possible to provide the rigid chain drive in a corner area of ​​an assembly that is to be linearly displaced by means of the rigid chain drive.

[0013] Although designs with more than two chain strands are possible and these more than two chain strands are also understood as a double chain set in the sense of the invention, it is preferred that the double chain set of a push chain drive according to the invention has exactly two chain strands that extend in different chain planes.

[0014] In particular, it is provided that the at least or exactly two chain strands are fed in non-parallel chain planes, which preferably enclose an angle between 60° and 120° with each other, in particular preferably an angle of 90°.

[0015] Such an angle is appropriate in many applications, particularly for the aforementioned arrangement of the rigid chain drive in a corner area of ​​a linearly displaceable assembly. The angled chain planes also mean that the storage of chain strand components that are not yet part of the chain assembly is often simplified if these chain strand components are stored in different chain planes. This applies both to designs in which the part of the two chain strands not yet joined to the chain assembly is stored in the form of a single elongated strand, and to designs in which one or both chain strands are stored in a spiral or other meandering manner in a chain storage unit.

[0016] The angle of the chain planes also opens up particularly advantageous possibilities for connecting the chain strands to one another.

[0017] It is particularly preferred if, in the at least two chain strands, each having a plurality of chain links, at least one coupling chain link of a first of the two chain strands and at least one coupling chain link of the second of the two chain strands are provided with corresponding engagement structures of a first type, which are designed to enter an engagement state in the contact region when the chain strands are extended. In this engagement state, the two coupling chain links are positively secured to one another in a first securing direction transverse to the main extension direction. Relative movement of the chain strands in the chain assembly is thus prevented, and the stability of the chain assembly is increased.

[0018] In particular, it can be provided that the at least one engagement structure of the first type on the coupling chain link of one of the two chain strands has an exposed extension which engages in a receiving space of the engagement structure on the other coupling chain link in the common chain assembly.

[0019] This receiving space is delimited by walls on both sides relative to the first securing direction, so that relative displacement of the chain links in the first securing direction is prevented or bidirectionally limited when the extension is arranged in the receiving space. The receiving space is preferably provided with a recess between the two walls on at least one side, so that the extension can pivot into the receiving space from the side upon pivoting movement of the corresponding coupling chain link. The extension is preferably extended such that it points in the direction of the main extension direction within the chain assembly.

[0020] The positive locking effect created by the engagement structures of the first type relates to a first securing direction transverse to the main extension direction. Furthermore, a corresponding positive locking effect can also be created by means of the engagement structures in a second securing direction, which is oriented orthogonally to the main extension direction and deviates from the first securing direction.

[0021] However, it is particularly advantageous if at least one coupling chain link of the first of the two chain strands and at least one coupling chain link of the second of the two chain strands are provided with an engagement structure of a second type, which is also designed to enter an engaged state in the contact area during extension, wherein in this engaged state the two coupling chain links are positively secured to one another in the second securing direction transverse to the main extension direction. This second securing direction deviates from the first securing direction and, in particular, forms a right angle with the first securing direction. Together, the engagement structures of the first and second type therefore completely secure chain links of the chain strands with respect to a displacement transverse to the main extension direction.

[0022] Preferably, the engagement structures of the first and second types are provided on the chain links in such a way that their engagement occurs alternately when the chain assembly is extended. Thus, an engagement structure of the first type is alternately engaged to positively secure the chain assembly in the first securing direction, and then an engagement structure of the second type is alternately engaged to positively secure the chain assembly in the second securing direction.

[0023] With regard to the engagement structure of the second type, it is also preferably provided that an exposed extension is provided on the coupling chain link of one of the two chain strands, which extension engages in the common chain assembly into a receiving space of the engagement structure on the other coupling chain link, wherein this receiving space is delimited on both sides in the second securing direction by walls, so that a relative displacement of the chain links in the second securing direction is prevented or is bidirectionally limited when the extension is arranged in the receiving space. As with the receiving space of the engagement structure of the first type, the receiving space is preferably provided with a recess at least on one side between the two walls, so that the extension can pivot into the receiving space from the side upon a pivoting movement of the other coupling chain link.

[0024] According to this development, two types of engagement structures are provided, which are structurally separate and, in particular, each provide exposed extensions and corresponding receiving spaces on the chain links of both chain strands. These two types of engagement structures are each primarily effective with respect to one securing direction, although this does not mean that the respective engagement structures provide a positive connection solely with respect to this first or second securing direction.

[0025] It is preferred if at least one coupling chain link is provided which has both engagement structures of the first type and of the second type. In particular, both an extension or a receiving space of the first engagement structure and an extension or a receiving space of the second engagement structure are provided on a single chain link. In particular, coupling chain links which have both engagement structures of the first type and of the second type are preferably provided in both chain strands. However, this is not absolutely necessary. Designs are also possible in which the chain links which have the engagement structures of the first type are different chain links than those chain links which have the engagement structures of the second type.

[0026] A particularly advantageous design is one in which the two chain strands comprise pairs of chain links arranged side by side at the same height, transverse to the main extension direction, within the chain assembly. Thus, each chain link of the first chain strand is arranged next to a chain link of the second chain strand, transverse to the main extension direction, within the assembly.

[0027] In this context, it is preferably provided that at least one of the engagement structures of the first type has an extension and a receiving space for receiving the extension, wherein the extension and the receiving space are not provided on chain links assigned to one another in pairs at the same height, but on chain links arranged offset from one another in the chain assembly.

[0028] It is particularly advantageous that the chain strands alternate between coupling chain links and intermediate chain links. The coupling chain links have the engagement structures of the first and preferably also the second type. The intermediate chain links are not coupled to chain links of the other chain strand and therefore have no engagement structure whatsoever.

[0029] In particular, it is provided that in the chain assembly, an intermediate chain link of one chain strand is arranged at the level of a coupling chain link of the other chain strand, wherein a coupling chain link or coupling chain links are provided in front of and / or behind the intermediate chain link, which is positively coupled to the coupling chain link of the other chain strand at the level of the intermediate chain link.

[0030] This design, with virtually offset coupling of the chain strands, offers a significant advantage: Due to the inventive two-level supply of the chain strands, the chain links of both chain strands are deflected at different levels in the contact area in order to achieve the alignment of the chain assembly and to be simultaneously connected to one another by means of the engagement structures. If, as proposed, the engagement structures of two chain links not arranged next to one another in the chain assembly engage with one another, but rather of successive chain links of both chain strands in the manner described, this ensures that the deflection movement of the coupling chain links to be coupled takes place one after the other.One of the two coupling chain links, which are intended to be coupled using the engagement structures, may already have achieved its alignment within the chain assembly when the coupling link of the other chain strand to be coupled with it is pivoted in its chain plane and thereby coupled. This reduces the complexity of the coupling process and means that the receiving space for the extension does not need to be larger than required to accommodate the extension. This reduces any remaining play in the chain assembly, which not only improves mechanical stability but also reduces noise generation during vibrations.

[0031] In a further development of the invention, at least one chain link of a first of the two chain strands and at least one chain link of the second of the two chain strands each have a toothing on an outer side, by means of which they can be driven by a gearwheel to extend and retract the chain assembly. The two toothings are each provided on the outer sides of the chain links, which point in the same direction within the chain assembly. Preferably, the teeth of the two chain links are aligned with each other in the area of ​​the chain assembly.

[0032] Such a design simplifies the drive of the chain assembly. While it is generally sufficient to drive one of the two chain strands and indirectly drive the second chain strand by coupling it to the driven chain strand, this leads to increased load on the coupling of the chain strands and thus to greater wear.

[0033] The two toothings on the two chain strands, which point in the same direction, allow each chain strand to be driven separately without significantly increasing the structural complexity of the drive. A common drive motor can be provided, driving one or more gears that mesh with the toothings. In the case of a single gear, this engages the toothings of both chain links, at least temporarily during extension, but preferably permanently. In an alternative design with multiple gears, these are arranged in a rotationally rigid manner on a common drive shaft driven by the motor.

[0034] In a further development of the invention, it is provided that at least one of the chain strands of the

[0035] Push chain drive, but preferably two chain strands, each having chain links with different shapes, in particular chain links of two different shapes.

[0036] The use of different chain links can be advantageous for various reasons. For example, the chain strand design described above, with coupling chain links that create a coupling connection with the other chain strand, and intermediate chain links that do not participate in the coupling of their chain strand with a second chain strand, is a possible design that demonstrates the value of such different chain links.

[0037] Another advantage is achieved if both chain strands each have two types of chain links which are provided in an alternating sequence at least in a partial section of the respective chain strands, wherein the two types of chain links are arranged overlapping in relation to a transverse direction to the main extension direction when arranged in the common chain assembly.

[0038] This means that an overlapping area extends along the main extension of the chain assembly, in which chain links from both chain strands are arranged alternately. This, in turn, is particularly advantageous when the rigid chain is subjected to shear stress. Because a force transmission path alternates between chain links from both chain strands in this situation, the chain strands are additionally protected against sideways breakage.

[0039] To achieve the overlap, it can be provided that the two types of chain links of both chain strands have a different extension in a transverse direction to the main extension direction or are arranged alternately offset with respect to a transverse direction to the main extension direction. In particular, one type of chain link of the first and second chain strands preferably has an overlap section which, in the extended chain assembly, is arranged between overlap sections of two chain links of the respective other chain strand with respect to the main extension direction. These overlap sections of both chain strands together form the above-mentioned overlap area of ​​the chain assembly.

[0040] This design of the chain assembly with an overlap zone does not necessarily require the presence of engagement structures of the type described above. However, the combination of overlap and engagement structures is preferred. In particular, it can be provided that the engagement structures are provided on the overlap sections themselves, which engage in the contact area upon extension, wherein the engagement structures are designed such that the two chain links are positively secured to one another in a securing direction transverse to a direction of extension of the chain strands behind the contact area. The overlap sections are well suited for the arrangement of the engagement structures, i.e. in particular for a design with exposed extensions or receiving spaces for accommodating these extensions.

[0041] The chain links of the push chain are preferably made predominantly of plastic, based on their mass. The use of plastic is particularly preferred because it allows the push chain to be constructed comparatively lightly. This is relevant, for example, when using a push chain drive in a vehicle, such as a slide-out system on a caravan trailer or motorhome.

[0042] The use of plastic can also be advantageous for cost reasons. Furthermore, there are applications where at least some metals are avoided to prevent interaction with application-specific magnetic fields or measuring devices, for example, in the context of magnetic resonance imaging.

[0043] However, in other fields of application where the reasons mentioned for using plastic play no or a lesser role, the chain links can also be made entirely or predominantly of metal.

[0044] In the case of chain links which are made at least partly of plastic, it is preferably provided that an outer surface of the chain links is formed at least predominantly by plastic surfaces.

[0045] Examples of plastics used for the chain links include polyamide (PA), high-density polyethylene (HDPE), high-molecular-mass polyethylene (UHMW-PE), polyetheretherketone (PEEK), polyphenylene sulfide (PPS) and thermoplastic polyurethanes (TPU).

[0046] A particularly preferred design provides that at least one chain link of one of the chain strands, but preferably chain links of both chain strands and especially preferably all chain links of both chain strands, each have two plastic parts that are connected to one another with or without a joining pin. These two plastic parts together form the majority of the outer surface of the respective chain links. The plastic parts can be connected directly to one another, for example by means of a snap connection or by means of a welding process. However, a design in which a joining element is provided, in particular a metallic joining element, is particularly preferred. This can in particular be a metallic joining pin that is inserted into a recess that has both plastic parts. However, it can also be a screw.

[0047] If the chain links of one or both chain strands are designed primarily from plastic, the plastic parts of the chain link or a plastic part preferably also form the toothing for driving the chain strand.

[0048] The chain links of the push chain are preferably pivotally mounted to one another, so that two adjacent chain links can pivot relative to one another about a defined pivot axis. To form a corresponding joint, it is preferably provided that one chain link has an opening that forms a bearing shell for the pivotal articulation of a subsequent chain link. If the chain link is designed from two plastic parts, it is preferably provided that both plastic parts have aligned openings to form the bearing shell. This ensures that the two plastic parts are held together by an adjacent chain link of the same chain strand.

[0049] Corresponding to this, the chain links preferably have a bearing pin for pivoting in the bearing shell of an adjacent chain link of the same chain strand. If the chain links are made of plastic, it can be provided that the bearing pin is formed by one of the two plastic parts or both plastic parts together. If a metallic joining pin is present for coupling the two plastic parts, it can be provided in particular that the joining pin is arranged within the bearing pin. A design is also possible in which the metallic joining pin itself forms the bearing pin and rests directly against the bearing shell of an adjacent chain link.

[0050] In a design with two plastic parts that together form the outer surface of the chain link for the most part, it can be advantageous if the toothing on at least some of the chain links is formed jointly by both plastic parts.

[0051] In addition to the rigid chain drive itself, the invention also relates to a slide-out assembly for a vehicle. This slide-out assembly comprises a vehicle-side assembly for attachment to the vehicle chassis and a slide-out-side assembly for attachment to a slide-out box. The slide-out assembly comprises the mechanical components for integrating a slide-out box into a vehicle, whereby the slide-out box itself does not have to be part of the slide-out assembly. However, the slide-out box can also be considered part of the slide-out assembly and, together with the components of the slide-out assembly described below, form an integrated product.

[0052] The slide-out arrangement according to the invention comprises a vehicle-side assembly for attachment to the chassis of a vehicle and a slide-out-side assembly for attachment to the slide-out box. The respective assemblies typically have one or more fitting elements that are fastened, in particular screwed, to the vehicle chassis or the slide-out box. Furthermore, the slide-out arrangement preferably has a guide device by means of which the vehicle-side assembly and the slide-out-side assembly can be displaced relative to one another in a guided manner. In particular, the guide device can use a box-side floor surface to which guide means such as rollers or corresponding rails can be attached, although the floor surface is preferably used only as a rolling surface for chassis-side rollers.Although a guide device is generally useful for the operation of the slide-out, this does not have to be part of the slide-out arrangement according to the invention, but can be implemented separately.

[0053] To extend and retract the slide-out box, the slide-out assembly comprises a drive system by means of which the vehicle-side assembly and the slide-out-side assembly can be moved relative to each other. According to the invention, this drive system is designed with a rigid chain drive as described above, i.e., it has a double chain set consisting of at least two chain strands that are fed at different chain levels and joined together in a contact area to form a chain assembly.

[0054] This chain assembly transmits a compressive force during extension and a tensile force during retraction, by means of which the distance between the slide-out-side assembly and the vehicle-side assembly is increased and decreased, thus causing the slide-out box to extend and retract. For the purpose of power transmission, the free end of the chain assembly is firmly attached to the slide-out-side assembly or firmly attached to the vehicle-side assembly. Chain storage for the chain strands and preferably a drive motor are preferably provided on the other assembly. The slide-out box, which is attached to the slide-out-side assembly, usually has at least a dimensionally stable outer side and preferably also dimensionally stable or flexible side walls and / or dimensionally stable or flexible top and bottom walls.

[0055] In particular, it is preferred that the drive system is designed and the double chain set is provided on it in such a way that extending the double chain set retracts the slide-out box and retracting the double chain set extends the slide-out box. This means that the slide-out-side and the vehicle-side assemblies are provided on the chassis and slide-out box respectively in such a way that increasing their distance causes the slide-out box to retract. In particular, the free end of the chain assembly can be attached to the slide-out-side assembly pointing towards the vehicle interior, for example at an inside end, in particular on a circumferential panel of the slide-out box, while the chain storage unit is attached to the inside of the vehicle wall.

[0056] According to the inventive design of the above-described push chain drive, the push chain drive has two chain strands which are fed in different and in particular in non-parallel chain planes, wherein the chain planes preferably enclose an angle between 60° and 120° with one another, in particular preferably an angle of 90°.

[0057] In particular, this allows the respective chain assemblies to be extended and retracted along corner edges of the slide-out box, wherein the respective chain strands are at least partially accommodated in chain storage units in the non-extended state, one of which is arranged on a vertical side wall and one on a horizontal top or bottom wall.

[0058] The use of only one double chain set for extending and retracting the slide-out box is generally possible. However, the use of multiple double chain sets, each comprising at least two chain strands, is preferred. Particularly preferred is at least two double chain sets, which drive the slide-out box symmetrically on the left and right sides and are located in the area of ​​the corners of the slide-out box. It is also possible to provide more than one double chain set per side, with two double chain sets being provided on each side of the double chain set, for a total of four double chain sets.

[0059] A preferred embodiment of a slide-out arrangement according to the invention with a plurality of double chain sets provides that at least one double chain set has two chain strands which are fed in the manner according to the invention from different chain levels and in particular preferably in non-parallel chain levels, while at least a second double chain set has two chain strands which are fed in parallel chain levels, in particular in an identical common chain level.

[0060] The invention relates, on the one hand, to the described slide-out assembly in the unassembled state, i.e., in particular, to the individual components forming a fitting set, which are designed for attachment in the described manner. However, the invention also relates to the described slide-out assembly in the assembled state, i.e., when integrated into a vehicle.

[0061] Furthermore, the invention also relates to the vehicle as a whole, in particular a mobile home or caravan trailer, with a slide-out arrangement. The vehicle has a vehicle interior and a slide-out arrangement with a slide-out box that is displaceable between a storage end position, in which an outer side of the slide-out box is substantially flush with the surrounding side wall of the vehicle, and a use end position, in which the slide-out box is extended outward to enlarge the vehicle interior. The slide-out arrangement is designed according to the previously described configuration and thus has a push-chain drive of the type described above.

[0062] In addition to the initially explained push chain drive and the slide-out arrangement as a preferred field of application for this, the invention also relates to further applications in which a push chain drive according to the invention can be used advantageously.

[0063] This includes, in particular, use in a magnetic resonance imaging device with an examination room. A magnetic resonance imaging device according to the invention comprises, as is typical for this type of device, a magnet for generating a homogeneous static magnetic field and a gradient coil for generating gradient fields in the examination room. Furthermore, the magnetic resonance imaging device has a radio-frequency coil for generating and / or receiving radio-frequency signals. These components are not specially designed in a magnetic resonance imaging device according to the invention.

[0064] The magnetic resonance imaging device according to the invention further comprises a patient table for positioning a patient during the examination and for moving the patient into the examination room. This is achieved by means of a linear drive.

[0065] According to the invention, this linear drive comprises a rigid chain drive of the type described above. Such a rigid chain drive is particularly suitable for moving the patient table because it can transmit high forces and the chain strands can nevertheless be made entirely or almost entirely of plastic.

[0066] The chain storage units of such a push chain drive can be mounted in a table support below the patient table, while the end of the push chain assembly can move the patient table bidirectionally.

[0067] The content of the priority application EP23180442.8 to the present application is incorporated by explicit reference into the present disclosure. This applies in particular to the design of a rigid chain drive with chain strands fed in parallel chain planes, to the design of chain storage units, and to the attachment of the rigid chain drive to vehicle-side and slide-out-side assemblies for use of the rigid chain drive in slide-out arrangements.

[0068] BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Further advantages and aspects of the invention emerge from the claims and from the following description of preferred embodiments of the invention, which are explained below with reference to the figures.

[0070] Fig. 1 to 3 show the core components of a design of a push chain drive according to the invention with two chain strands in different representations.

[0071] Fig. 4 shows the chain links of a section of the chain assembly assembled by the push chain drive.

[0072] Fig. 5A to 5D shows the four different chain links of the two chain strands in separate representation.

[0073] Fig. 6A to 6F illustrate the process of joining the chain strands in an assembled chain assembly.

[0074] Fig. 7A and 7B show an exemplary vehicle with a slide-out system in the retracted and extended state.

[0075] Fig. 8 and 9 illustrate possible arrangements of push chain drives as part of the slide-out system.

[0076] Figs. 10A and 10B show an exemplary magnetic resonance imaging device.

[0077] Fig. 11 illustrates a possible arrangement of push chain drives in this magnetic resonance imaging device.

[0078] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0079] Figures 1 to 3 show the core components of an embodiment of a push chain drive 10 according to the invention.

[0080] The push-pull chain drive 10 has two chain strands 20A, 20B, each composed of a plurality of chain links 30A, 30B, 32A, 32B. The chain strands 20A, 20B are designed to be extended and retracted during operation. During the extension of the chain strands 20A, 20B, the chain links of these chain strands are guided into a contact area 12, from which they form a common chain assembly 60, which is then extended in a main extension direction Z.

[0081] The chain links 30A, 30B, 32A, 32B of the chain strands 20A, 20B will be discussed in more detail below. However, it should already be explained at this point that the chain links of the chain strands are pivotally movable and are connected in parallel to the following and previous chain links of the respective chain strand, so that the chains thus have a defined chain plane to which the pivot axis of the chain links is orthogonal.

[0082] Furthermore, it should be mentioned here that the chain strands are designed as unidirectionally bendable chain strands. This means that, starting from a longitudinally extended shape of a chain strand, bending in one direction in the plane of the chain is prevented. This is achieved in particular by the outer shape of the chain links, as will be explained below.

[0083] As can be seen from Figures 1 to 3, during extension, the still separate sections 22A, 22B of the chain strands 20A, 20B are fed from different directions X,Y and are each deflected by 90° in front of the contact area 12 in order to be guided further in the main extension direction Z, namely in the form of the chain assembly 60 already mentioned.

[0084] The chain strands 20A, 20B are preferably never completely separated. If the chain strands 20A, 20B are retracted to a significant extent, the chain assembly is shortened. However, some chain links of the chain strands preferably remain part of a short end-side chain assembly 60.

[0085] In the retracted state, i.e., with the chain assembly at its shortest and the separated sections 22A, 22B of the chain strands 20A, 20B at their maximum length, the chain strands 20A, 20B are in a stowed position. This can, for example, be an unbent stowed position in which the sections 22A, 22B extend linearly in the X-direction or Y-direction. However, it is preferred that a chain storage unit be provided for each of the chain strands 20A, 20B, within which the chain strands are stored in a spiral or otherwise meandering stowed position.

[0086] During the aforementioned extension and retraction of the chain strands, and thus during the extension or retraction of the common chain assembly 60, a component attached to the end 62 of the chain assembly 60 can be displaced bidirectionally. The component can be, for example, a slide-out box of a mobile home or a patient table of an MRI machine.

[0087] While a tensile force is exerted on the connected assembly when the chain strands 20A, 20B are retracted and thus when the chain assembly 60 is retracted and simultaneously shortened, which does not pose any challenge to a chain drive, a pushing force is exerted on the end 62 and thus the connected component when the chain strands 20A, 20B are extended and thus when the chain assembly 60 is extended and simultaneously lengthened.

[0088] To ensure that such a thrust force can be exerted without the chain strands slipping, thus making the transmission of a thrust force difficult or impossible, the chains are combined into a chain assembly. The two chain strands that together form the chain assembly support each other, thus making it more difficult for the chain strands to accidentally break away from the desired chain path. The chain links of the two chain strands can be designed to support each other only through contact, but not interlock. In principle, this can be sufficient due to the unidirectional bendability of the chain strands.

[0089] However, it is advantageous and provided here that the chain strands also engage with each other and thus an even greater degree of stability is achieved in the area of ​​the chain assembly 60.

[0090] In this case, the push-chain drive comprises a drive motor 70, on whose output shaft a gear 72 is mounted, which engages with a second gear 74. This can be seen in Fig. 3, in which a housing of the push-chain drive 10 is shown in section.

[0091] The aforementioned second gear 74 acts on the chain assembly 60. For this purpose, the chain assembly 60 has a toothing 50, which is provided on the chain links 30A, 30B, 32A, 32B in a form explained in more detail below. However, it should already be explained at this point that the gear 74 or several torsionally rigid gears 74 with toothings are in engagement with both chain strands 20a, 20B, so that none of the chain strands is subjected to force exclusively indirectly via the other chain strand.

[0092] Figure 4 shows, in separate form, four different chain links 30A, 30B, 32A, 32B, from which the chain strands 20A, 20B are constructed. The orientations of the chain links 30A, 30B, 32A, 32B in Figure 4 correspond to the orientation in the chain assembly 60. However, to illustrate the respective shapes, the chain links are shown spaced apart from one another. Figures 5A to 5D show the chain links 30A, 30B, 32A, 32B again separately and from different angles.

[0093] The chain links are explained further using Fig. 4 to 5D.

[0094] The two chain strands 20A, 20B are each constructed from two types of chain links. Chain strand 20A consists at least predominantly of chain links 30A, 32A, which are alternately pivotably mounted to one another to form chain strand 20A. Chain strand 20B consists at least predominantly of chain links 30B, 32B, which are alternately pivotably mounted to one another to form chain strand 20B.

[0095] All chain links 30A, 30B, 32A, and 32B share various aspects. All chain links have an opening 54 that provides a bearing shell for connecting a subsequent chain link. All chain links also have a bearing pin 56 that is inserted into the opening of an adjacent chain link and forms a joint with it, enabling buckling deformation in the chain plane of the respective chain strand.

[0096] As can be clearly seen in Figs. 5A to 5D, the chain links are each primarily constructed from two components 34, 36. Polyamide (PA), for example, is a possible material, but all of the other materials mentioned above are also suitable. The two plastic parts 34, 36 can be directly locked together. In this case, they are connected by means of a joining pin 38 or a joining screw 38 that extends through the bearing pin 56.

[0097] The opening 54 of the chain links 30A, 30B, 32A, 32B is formed by openings in both plastic parts 34, 36, so that when the chain strand is joined, the plastic parts 34, 36 are held together in the area of ​​the openings by the adjacent chain link mounted here and its joining pin 38.

[0098] As the figures further show, all chain links 30A, 30B, 32A, 32B are each provided with a toothing 50. In the case of chain links 30B, 32A, 32B, the toothing 50 is provided on only one of the components 34, 36. Only in the case of chain link 30A, in which the pivot axis of the chain link extends parallel to the toothing surface of the toothing 50 and in which the toothing 50 is comparatively wide, do both plastic components 34, 36 together form the toothing 50. With reference to Figure 4, the differences between the chain links with regard to the interaction of the chain strands 20A, 20B in forming the chain assembly 60 are explained below.

[0099] According to the illustration in Fig. 4, one chain link of the chain strand 20A and one chain link of the chain strand 20B form a pair, namely in this case the chain links 30A, 30B on the one hand and the chain links 32A, 32B on the other hand. These chain links form a pair in that they are directly adjacent to one another in the chain assembly and the toothings on the chain links are aligned with one another in the chain assembly.

[0100] Furthermore, it can be clearly seen in Fig.4 that the two chain strands 20A, 20B, with the chain links 30A, 32A on the one hand and with the chain links 30B, 32B on the other hand, have two different types of chain links.

[0101] The chain links 30A, 32B are designed as coupling chain links. This means that they are specially designed to create a connection between the chain strands, as will be explained below. These chain links 30A, 32B are wider in a transverse direction X than the other chain links 30B, 32A.

[0102] The other chain links 30B, 32A represent intermediate chain links. This means that they are not directly involved in the coupling of the chain strands 20A, 20B.

[0103] As can be seen from the described pairwise arrangement of the chain links and from the described designs of the chain links 30A, 32B as coupling chain links, the coupling chain links 30A, 32B are offset from one another. When the chain strands 20A, 20B are extended, a coupling chain link 30A of the chain strand 20A and a coupling chain link 32B of the chain strand 20B alternately become part of the common chain assembly 60.

[0104] As can be seen from Fig. 4, but also from Figures 5A and 5D, the coupling chain links 30A, 32B are provided with cooperating engagement structures.

[0105] In the case of the chain link 30A, the engagement structures are formed by two projections 40A, 42B projecting freely forwards and backwards, which are provided on an overlapping section 52 projecting towards the other chain strand.

[0106] Correspondingly, the engagement structures in the case of chain link 32B are formed by two receiving spaces 40B, 42A, which are also provided at an overlapping section 52 of chain links 32B. These receiving spaces 40B, 42A are intended to receive the extensions 40A, 42B and are suitably dimensioned for this purpose. The receiving spaces are each provided with two opposing walls that limit the mobility of the extension 40A, 42B inserted therein. The receiving spaces 40B, 42A are not only open at the front so that the extensions 40A, 42B can protrude into them, but are also provided with a recess on another side so that the extensions 40A, 42B can pivot in during the joining of the chain strands 20A, 20B in the contact area 12.

[0107] The type of coupling provided here is explained using Figs. 6A to 6F. The figures show a partial section of the chain strands 20A, 20B during the extension movement, i.e. during an extension of the chain assembly 60 and thus the exertion of a thrust force on an assembly attached to the end 62 of the chain assembly.

[0108] Fig. 6A first illustrates that the two chain strands 20A, 20B are constructed from alternately arranged chain links 30A, 30B and 32A, 32B, respectively. Beyond the contact area 12, the chain strands 20A, 20B form the common chain assembly 60, wherein, in the state of Fig. 6A, the last chain links arranged in their desired position in the chain assembly 60 are a coupling chain link 32B of the chain strand 20B and an adjacent intermediate chain link 32A of the chain strand 20A.

[0109] Starting from this intermediate position, the further extension process is now explained:

[0110] When the chain assembly is extended further in the Z direction by means of the drive motor 70, the chain assembly pulls along additional chain links of the chain strands 20A, 20B that have not yet been included in the chain assembly 60. In the situation of Fig. 6A, the next chain links to be added to the chain assembly are a coupling chain link 30A of the chain strand 20A and an intermediate chain link 30B of the chain strand 20B.

[0111] During the transition from the state of Fig. 6A to the state of Fig. 6B, the extension 42B of the coupling chain link 30A moves into the receiving space 42A of the coupling chain link 32B of the chain strand 20B, which is already contained in the chain assembly 60. The relative movement of the coupling chain link 30A with respect to the coupling chain link 32B is therefore a purely 2-dimensional pivoting movement. The receiving space 42A therefore does not need to have a clear width that is significantly larger than the thickness of the extension 42B. The intermediate chain link 30B adjacent to the chain link 30A is also only pivoted, but as an intermediate chain link, it does not establish any transverse connection to the chain strand 20A.

[0112] The state shown in Fig. 6B is established. In this state, the chain links 30B, 32A that have just been pivoted in now form the youngest chain links of the chain assembly 60. The next chain links to be inserted into the chain assembly 60 are the chain links 32B, 32A that are in the pivoting movement shown in Fig. 6B.

[0113] During the transition to the state shown in Fig. 6C, the previously described process is repeated in reverse. The two chain links 32B, 32A now pivot inward, with the receiving space 42A pivoting onto the extension 40A and thereby receiving it.

[0114] The joining of the engagement structures 42B, 42A on the one hand and the engagement structures 40A, 40B on the other hand leads to the formation of transverse connections between the chain strands 20A, 20B. These engagement structures form a different type of securing mechanism. The receiving space 42A and the extension 42B engaged therein secure the chain strands 20A, 20B primarily in the X direction. The receiving space 40B and the extension 40A engaged therein secure the chain strands 20A, 20B primarily in the Y direction. Together, the engagement structures of the first and second type ensure stable securing of the chain strands, preventing the chain strands of the chain assembly from separating in any transverse direction.

[0115] With the state of Fig. 6C, a state similar to that of Fig. 6A is reached. This means that, again next, during the transition to the state of Fig. 6D, a coupling chain link 30A and an intermediate chain link 30B are added to the chain assembly 60. During the further transition to the state of Fig. 6E, a coupling chain link 32B and an intermediate chain link 32A are then added again. During the transition to the last of these representations, the state of Fig. 6E, a coupling chain link 30A and an intermediate chain link 30B are then added to the chain assembly 60.

[0116] Based on the state in Fig. 6F, another special feature of the resulting chain assembly 60 is explained. In addition to the cross connections between the chain strands formed by the engagement structures 40A, 40B, 42A, 42B, the chain assembly 60 is also particularly stable because it creates an overlap area 80 that extends in the main extension direction Z. The overlap sections 52 of the coupling chain links 30A, 32B extend into this overlap area 80. The consequence of this is that shear forces acting on the chain assembly 60 are at least partially diverted via this overlap area 80, and thus the coupling chain links 30A, 32B are alternately arranged in the force flow path. The coupling chain links 30A, 32B are thereby pressed against one another, thereby increasing the stability of the chain assembly 60.

[0117] With reference to Figs. 7A, 7B and 8 and 9, a preferred field of application for a push chain drive of the type described is explained, namely the use in motor vehicles and in particular the use in slide-out systems of motor vehicles.

[0118] Figs. 7A and 7B show a vehicle 150 in the form of a motorhome. This vehicle 150 is equipped with a slide-out assembly 100, which is provided for moving a slide-out box 120 that can be displaced between a retracted position and an extended position. This allows a vehicle interior 110 to be enlarged when the vehicle is stationary.

[0119] The slide-out box 120, in turn, has an outer side 121, which, in the retracted state of Fig. 7A, is substantially aligned with a side wall 102 of the vehicle. In this state of Fig. 7A, the movement of the vehicle 150 is possible.

[0120] As the extended state of Fig. 7B shows, the slide-out box 120 has, in addition to the outer side 121, two side walls 122, 123, an upper wall 124 forming the ceiling, and a lower wall 125 forming the floor. Fig. 7B shows the extended state, which is used during stationary operation of the vehicle 150 and by which the vehicle interior 110 of the vehicle is enlarged.

[0121] The displacement of the slide-out box 120 takes place in a slide-out arrangement 100 according to the invention and in a vehicle 150 according to the invention by means of at least one push-chain drive 10 of the type described above. Although the extension requires considerable force, the push-chain drive 10 based on plastic chain links is sufficiently stable, even with a high number of retraction and extension cycles.

[0122] Fig. 8 illustrates a preferred arrangement of several rigid chain drives 10 for the joint displacement of the slide-out box 120. Here, each rigid chain drive 10 is designed with two chain strands 20A, 20B such that the chain links of the chain strands 20A, 20B are fed in different chain planes. With respect to the rigid chain drive 10 in the upper left corner of the slide-out box 120 (seen from the outside), one chain strand 20A is fed in, the chain plane of which is spanned by the X and Z axes, while another chain strand 20B is fed in the chain plane spanned by the Y and Z axes. In the contact area 12, the chain strands 20A, 20B are brought together and extended in the Z direction as a common chain assembly 60. This extension movement of the chain assembly 60 is preferably used to retract the slide-out box 120, i.e. to transfer it from the state of Fig. 7B to the state of Fig. 7A.

[0123] The drive motors 70 are not shown in Fig. 8. In principle, it is possible to design each rigid chain drive 10 with its own drive motor 70, as shown in Figs. 1 to 3. Alternatively, a common motor can also be provided to drive several rigid chain drives, in particular for the two rigid chain drives on each side of the slide-out box 120.

[0124] Fig. 9 shows an alternative design. Here, the push-chain drives 10 of the type described are again provided at the upper corners of the slide-out box 120, in which the chain strands 20A, 20B are fed in different chain planes. However, in this design, the respective lower push-chain drives 11 are designed differently, namely such that both chain strands 21A, 21B are fed in a common chain plane spanned by the axes Z and Y. Regarding the construction of such a push-chain drive, reference is made to priority application EP23180442.8, the disclosure of which regarding such push-chain drives, and in particular Fig. 6, together with the associated description sections, is hereby incorporated into the disclosure of the present patent application.

[0125] Figs. 10A, 10B, and 11 show a further field of application for a push-chain drive 10 of the described type, namely a magnetic resonance imaging device 200. This magnetic resonance imaging device 200 has, in a generally known manner, an examination chamber 210 surrounded by a magnet 220, a gradient coil 222, and a radiofrequency coil 224. This is illustrated in Fig. 10A.

[0126] The magnetic resonance imaging device 200 includes a patient table unit 230, which consists of a table base 232 and a patient table 234. The table base 232 is fixed in position. The patient table 234, in contrast, is movable to allow the patient lying on the patient table 234 to be moved into and out of the examination room. For this purpose, the patient table 234 is guided by guide rails 236.

[0127] Fig. 10B shows the patient table 234 in a displaced state, in which it is at least partially located in the examination room 210. For the purpose of displacement, a linear drive is provided, which is mounted on a

[0128] Sliding chain drive 10 of the type described above.

[0129] Fig. 11 illustrates how the push chain drive 10 is integrated into the table base 232. It can be seen that the two chain strands 20A, 20B are each fed at different chain levels to form a chain assembly 60 suitable for transmitting push forces in the contact area, as already described above. The patient table 234 is provided at the distal end 62 of the chain assembly, which can thus be moved into and out of the examination room 210.

[0130] In the case of the push-chain drive 10 of the magnetic resonance imaging device 200 presented here, it is also provided that the chain links are made at least predominantly of plastic in the manner described, in particular again of two components 34, 36. Additionally, it can be provided here that the chain links are made entirely of plastic by omitting the joining pin 38 in favor of a snap connection between the two components. It can also be provided that the joining pin 38 itself is made of plastic.

[0131] The use of non-magnetizable and preferably non-metallic materials for those parts of the patient table 234 that enter the examination room 210, and thus also for the chain assembly 60, is considered advantageous. On the one hand, unwanted magnetic attractions are avoided. On the other hand, metallic parts lead to image distortions and can heat up to a disturbing degree. The use of plastics for the linear drive therefore represents a significant advantage.

Claims

Patent claims 1. A push chain drive (10) with at least one double chain set, having the following features: a. the double chain set has at least two chain strands (20A, 20B) which are fed independently of one another to a contact area (12) when the double chain set is extended, and b. the at least two chain strands (20A, 20B) come into contact with one another in the contact area (12) when the chain strands (20A, 20B) are extended in such a way that they can be extended in a main extension direction (Z) as a mutually supporting or holding one another as a common chain assembly (60), and c. the at least two chain strands (20A, 20B) are fed in different chain planes (XY, YZ).

2. A push chain drive (10) according to claim 1 with the following further feature: a. the at least two chain strands (20A, 20B) are fed in non-parallel chain planes (XY, YZ) which preferably enclose an angle between 60° and 120° with one another, in particular preferably an angle of 90°.

3. Push chain drive (10) according to one of claims 1 or 2 with the following further Features: a. the at least two chain strands (20A, 20B) each have a plurality of chain links (30A, 32A, 30B, 32B), and b. at least one coupling chain link (30A) of a first of the two chain strands (20A) and at least one coupling chain link (32B) of the second of the two chain strands (20B) are provided with engagement structures (40B, 40A) of a first type, which are designed to come into an engagement state when extended in the contact region (12), wherein in this engagement state the two coupling chain links (30A, 32B) are positively secured to one another in a first securing direction (Y) transverse to the main extension direction (Z).

4. Push chain drive (10) according to claim 3 with the following further features: a. the at least one engagement structure (40B, 40A) of the first type has an exposed extension (40A) on the coupling chain link (30A) of one of the two chain strands (20A), which extension engages in a receiving space (40B) of the engagement structure on the other coupling chain link (32B) in the common chain assembly (60), and b. the receiving space (40B) is delimited on both sides in the first securing direction (Y) by walls, so that a relative displacement of the coupling chain links (30A, 32B) in the first securing direction (Y) is prevented or is bidirectionally limited when the extension (40A) is arranged in the receiving space (40B).

5. Push chain drive (10) according to claim 3 or 4 with the following further feature: a. at least one coupling chain link (30A) of the first of the two chain strands (20A) and at least one coupling chain link (32B) of the second of the two chain strands (20B) are provided with an engagement structure (42A, 42B) of a second type, which is designed to come into an engagement state in the contact area (12) when extended, wherein in this engagement state the two coupling chain links (30A, 32B) are positively secured to one another in a second securing direction (X) transverse to the main extension direction (Z), wherein the second securing direction (X) deviates from the first securing direction (Y).

6. A push chain drive (10) according to claim 5 with the following additional features: a. the at least one engagement structure (40A, 42B) of the second type has an exposed extension (42B) on the coupling chain link (30A) of one of the two chain strands (20A), which extension engages in a receiving space (42A) of the engagement structure on the other coupling chain link (32B) in the common chain assembly (60), and b. the receiving space (42A) is delimited on both sides in the second securing direction (X) by walls, so that a relative displacement of the coupling chain links (30A, 32B) in the second securing direction (X) is prevented or is bidirectionally limited when the extension (42B) is arranged in the receiving space (42A). preferably with the following additional feature: c.the at least one engagement structure (40B, 40A) of the first type and the at least one engagement structure (42B, 42A) of the second type are designed such that an extension and / or a receiving space of the engagement structure (40B, 40A) of the first type and an extension and / or a receiving space of the engagement structure (42B, 42A) of the second type are provided on at least one of the coupling chain links (30A, 32B).

7. A push chain drive (10) according to one of claims 3 to 6 with the following additional features: a. the two chain strands (20A, 20B) have chain links (30A, 30B; 32A, 32B) assigned to one another in pairs, which are arranged next to one another at the same height in the chain assembly (60) transversely to the main extension direction (Z), and b. at least one of the engagement structures (40A, 40B) of the first type has an extension (40A) and a receiving space (40B) for receiving the extension (40A), wherein the extension (40A) and the receiving space (40B) are not provided on chain links assigned to one another in pairs at the same height.

8. Push chain drive (10) according to one of the preceding claims with the following additional features: a. at least one chain link (30A, 32A) of a first of the two chain strands (20A) and at least one chain link (30B, 32B) of the second of the two chain strands (20B) each have a toothing (50) on an outer side, by means of which they can be driven by a gear (74), and b. the two toothings (50) are each provided on outer sides which point in the same direction in the chain assembly (60).

9. A push chain drive (10) according to any one of the preceding claims, having the following further feature: a. in the chain assembly (60), at least one tooth of the toothing (50) on the first of the two chain links is aligned with at least one tooth of the toothing (50) on the second of the two chain links.

10. A push-chain drive (10) according to claim 8 or claim 9 with the following further feature: a. the push-chain drive (10) has a drive motor (70) which engages the toothing (50) of the chain links (30A, 30B, 32A, 32B) of at least one chain strand (20A, 20B) via at least one gear (72, 74).

11. A push chain drive (10) according to one of claims 8 to 10 with the following further feature: a. at least two tooth edges are provided which are connected to one another in a rotationally rigid manner and which are in engagement with the toothing of each chain strand.

12. Push chain drive (10) according to one of claims 8 to 10 with the following further feature: a. a gear wheel (74) is provided which is designed and / or positioned such that it is at least temporarily and in particular preferably permanently in engagement with toothings (50) on chain links (30A, 30B, 32A, 32B) of both chain strands (20A, 20B).

13. A push chain drive (10) according to any one of the preceding claims, having the following further feature: a. at least one of the chain strands (20A, 20B) has at least two types of chain links (30A, 30B, 32A, 32B) with different shapes.

14. A push-chain drive (10) according to claim 13, having the following additional features: a. both chain strands (20A, 20B) each have two types of chain links (30A, 30B, 32A, 32B), which are provided in an alternating sequence in at least a partial section of the respective chain strands (20A, 20B), and b. the two types of chain links (30A, 30B; 32A, 32B) are arranged in the common chain assembly (60) in an overlapping manner with respect to a transverse direction (Y) relative to the main extension direction (Z), so that when a force acts on one end of the chain assembly (60) in the main extension direction (Z), the force is transmitted by means of a force flow which runs alternately through chain links (30A, 32A) of the first chain strand (20A) and through chain links (30B, 32B) of the second chain strand (20B).

15. A push chain drive (10) according to claim 14 with the following further features: a. to achieve the overlap, the two types of chain links (30A, 30B, 32A, 32B) of both chain strands (20A, 20B) have a different extension in a transverse direction (Y) to the main extension direction (Z) or are arranged alternately offset with respect to a transverse direction to the main extension direction, and b. one type of chain link (30A, 32B) of the first and second chain strands (20A, 20B) are each provided with an overlapping section (52) which, in the extended chain assembly (60), is arranged between overlapping sections (52) of two chain links (30A, 32A) of the respective other chain strand (20B, 20A) with respect to the main extension direction (Z).

16. A push chain drive (10) according to claim 15 with the following further feature: a. engagement structures (40A, 40B, 42A, 42B) are provided on the overlapping sections (52), which engagement structures are designed to engage in the contact area (12), wherein these engagement structures (40A, 40B, 42A, 42B) are designed such that the respective chain links (30A, 32B) are positively secured to one another in a securing direction (X, Y) transverse to the main extension direction (Z) of the chain assembly (60).

17. A push-chain drive (10) according to one of the preceding claims, having the following further feature: a. at least one chain link (30A, 30B, 32A, 32B) of one of the chain strands has two plastic parts (34, 36) which are connected to one another with or without a joining pin (38).

18. A push chain drive (10) according to claim 17 with at least one of the following additional features: a. one of the plastic parts (34, 36) forms a toothing (50) for driving the chain strand, and / or b. the chain link (30A, 30B, 32A, 32B) has an opening (54) which forms a bearing shell for the pivotable articulation of a next chain link, wherein preferably both plastic parts (34, 36) have aligned openings (54) to form the bearing shell, and / or c. the chain link (30A, 30B, 32A, 32B) has a bearing pin (56) for pivotally arranged in a bearing shell of a next chain link, which is formed by one of the plastic parts (34, 36) or both plastic parts (34, 36), wherein preferably a joining pin (38) of the chain link (30A, 30B, 32A, 32B) is arranged within the bearing pin (56).

19. A push-chain drive (10) according to any one of the preceding claims, having at least one of the following additional features: a. the at least two chain strands (20A, 20B) are each designed as unidirectionally bendable chain strands (20A, 20B), and / or b. the two chain strands (20A, 20B) are designed to form a positive coupling with one another in the contact region (12).

20. A slide-out arrangement (100) for a vehicle (150) having the following features: a. the slide-out arrangement (100) comprises a vehicle-side assembly for attachment to the chassis of the vehicle (150), and b. the slide-out arrangement (100) comprises a slide-out-side assembly for attachment to a slide-out box (120), and c. the slide-out arrangement (100) comprises a drive system by means of which the vehicle-side assembly and the slide-out-side assembly can be moved relative to one another, characterized by the following additional feature: d. the drive system comprises a push-chain drive (10) according to one of claims 1 to 19.

21. Slide-out arrangement (100) according to claim 20 with the following further features: a. the slide-out arrangement (100) has at least two push-out chain drives (10), and b. at least one push-out chain drive (10) has two chain strands (20A, 20B) that are fed in different chain planes and in particular preferably in non-parallel chain planes, and c. at least one push-out chain drive (11) has two chain strands (21A, 21B) that are fed in parallel chain planes, in particular in an identical chain plane.

22. Slide-out arrangement (100) according to one of claims 20 or 21 with at least one of the following further features: c. the slide-out arrangement (100) comprises a slide-out box (120) which is attached to the slide-out-side assembly, wherein the slide-out box (120) has at least one dimensionally stable outer side (121) and preferably also dimensionally stable or dimensionally flexible side walls (122, 123) and / or dimensionally stable or dimensionally flexible top and bottom walls (124, 125), and / or d. the push-chain drive (10) is coupled to the slide-out-side assembly and the vehicle-side assembly in such a way that by extending the chain assembly (60) an outer side (121) of the slide-out box (120) is retracted and by retracting the chain assembly (60) the outer side (121) of the slide-out box (120) is extended, and / or e.the push chain drive (10) is designed such that the chain strands (20A, 20B) are arranged in a retracted state in a chain storage unit which is part of the vehicle-side assembly.

23. A vehicle (150), in particular a mobile home, comprising a slide-out arrangement (100) having the following features: a. the vehicle has a vehicle interior (110), and b. the vehicle has a slide-out arrangement (100) with a slide-out box (120) which is displaceable between a storage end position, in which an outer side (121) of the slide-out box (120) is substantially aligned with the surrounding side wall (102), and a use end position, in which the slide-out box (120) is extended outwards to enlarge the vehicle interior (110), characterized by the following additional feature: c. the slide-out arrangement (100) is designed according to one of claims 21 or 22.

24. A magnetic resonance imaging device (200) having the following features: a. the magnetic resonance imaging device (200) has a magnet (220) for generating a homogeneous static magnetic field in an examination space (210) of the magnetic resonance imaging device, b. the magnetic resonance imaging device (200) has a gradient coil (222) for generating gradient fields in the examination space (210), c. the magnetic resonance imaging device (200) has a radio-frequency coil (224) for generating and / or receiving radio-frequency signals, d. the magnetic resonance imaging device (200) has a patient table for supporting a patient during the examination, e. the magnetic resonance imaging device has a linear drive by means of which the patient table and the gradient coil can be moved relative to one another, characterized by the following further feature: f. the linear drive has a push-chain drive according to one of claims 1 to 19.

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