SHOOTING CHAIN, DRIVE DEVICE AND LIFTING PLATFORM

Description

Technical area

[0001] The invention relates to a push chain with chain links which are connected to one another by joints and have stop surfaces, whereby a straight alignment of the chain links occurs when the stop occurs, but the chain links can be pivoted in the other direction relative to one another and wherein the chain links have engagement elements for a pinion drive. Technical background

[0002] Push chains are widely used as power transmission links, particularly when spanning stroke ranges where they are long, stretched, and usually unguided. A drive applies a force to the chain, which is transmitted primarily in a compressive direction to an element connected to the chain. The drive is usually a pinion drive, with at least one pinion engaging the push chain and driving it. A counterforce, usually in the form of a guide rail, holds the push chain in the engagement area of ​​the pinion(s).

[0003] A common application is lifting platforms which can be carried by several push chains, for example, which, due to the number and mutually supporting arrangement of the push chains, assume the desired height position in a stable manner. Basically, there are two types of push chains:

[0004] In one case, the chain links are flat plates in parallel rows, connected by joints, similar to a bicycle chain. To serve as a push chain, the plates must have stop surfaces for the extended alignment, as is known, for example, from EP 1 006 074 B1. This does not allow for high stability under high forces.

[0005] The other type of push chain essentially consists of U-shaped chain links that rest on each other in the supporting function of the push chain.

[0006] Such push chains are known from DE 198 05 157 A1, DE 10 2016 110 949 B4, and an embodiment of DE 20 2014 004 827 U1. Connecting plates are inserted within the U-shaped chain links, connecting the U-shaped chain links to each other via joints. Stability against lateral deflection of the push chain in the extended state is achieved only through the joints and connecting links, which is insufficient under high forces and high stability requirements, especially against buckling.

[0007] DE 10 2014 007 458 B4 and embodiments of DE 20 2014 004 827 U1 eliminate the need for connecting plates by designing the U-shaped chain links with offset plates, whereby the chain links are encompassed by the offset plates of the subsequent U-shaped chain link. While this creates greater stability than the aforementioned prior art, it is associated with complex and expensive manufacturing due to the offset.

[0008] DE 10 2012 214 270 A1, which discloses a push chain according to the preamble of claim 1, proposes a push chain made of similar U-shaped chain links that are connected to one another by plates attached to the U. However, this connection only eliminates the need for offsetting because the chain links are arranged alternately offset from one another. However, this mutual offset does not allow for stiffening through a mutually stabilizing engagement of the surfaces of the U-legs and the plates with the subsequent chain link. There is no interlocking of the surfaces of successive chain links, as is the case with the offsets of the chain links in DE 10 2014 007 458 B4, where one chain link engages the other. Therefore, in this push chain, too, stability, particularly against buckling, is essentially achieved only by the joints, which is susceptible to wear because the surface contact is lost. Object of the invention

[0009] The invention is therefore based on the object of making available a simple-to-manufacture push chain compared to the cited prior art, which can absorb high forces even over large unguided stroke lengths and remains stable. General description of the invention

[0010] In the following, the terms "have," "have," "comprise," or "include," or any grammatical variations thereof, are used non-exclusively. Accordingly, these terms can refer both to situations in which, besides the features introduced by these terms, no further features are present, or to situations in which one or more further features are present. For example, the expression "A has B," "A has B," "A comprises B," or "A includes B" can refer both to the situation in which, apart from B, no further element is present in A (i.e., a situation in which A consists exclusively of B), and to the situation in which, in addition to B, one or more further elements are present in A, for example, element C, elements C and D, or even further elements.

[0011] Furthermore, it should be noted that the terms "at least one" and "one or more," as well as grammatical variations of these terms, when used in connection with one or more elements or features and intended to express that the element or feature may be provided singly or multiple times, are generally used only once, for example, when the feature or element is first introduced. Upon subsequent re-mention of the feature or element, the corresponding term "at least one" or "one or more" is generally no longer used, without limiting the possibility that the feature or element may be provided singly or multiple times.

[0012] Furthermore, the terms "preferably," "in particular," "for example," or similar terms are used below in connection with optional features, without limiting alternative embodiments. Thus, features introduced by these terms are optional features, and these features are not intended to limit the scope of the claims, and in particular the independent claims. Thus, as those skilled in the art will recognize, the invention can also be carried out using other embodiments. Similarly, features introduced by "in one embodiment of the invention" or "in an embodiment of the invention" are understood as optional features, without limiting alternative embodiments or the scope of the independent claims.Furthermore, these introductory expressions are intended to leave untouched all possibilities of combining the features introduced thereby with other features, whether optional or non-optional.

[0013] In a push chain of the type mentioned above, this is achieved in that U-shaped outer chain links and U-shaped inner chain links are arranged in an interlocking manner, with the inner chain links resting with their outer sides on the inner sides of the outer chain links, and with the chain links having a complete U-shape for half of their longitudinal extent, and with the legs of the U having longitudinally projecting plates for the other half of their longitudinal extent, that joints are mounted both in the legs and in the plates in such a way that each joint movably connects an outer chain link to an inner chain link, and that due to the dimensions of the chain links, these are supported with the stop surfaces on the bases of the U when the push chain is stretched out,and at the same time all outer chain links and all inner chain links with their respective stop surfaces on the legs of the U are supported on the stop surfaces of the plates of the following chain link.

[0014] The advantage of the inventive rigid chain lies, on the one hand, in the large mutual contact surfaces of the chain links in the supporting function, which encompass both the bases of the U-shaped links of the inner and outer chain links, as well as the outer edges of the legs of these U-shaped links or the link plates. Furthermore, the legs of the U-shaped links and the link plates rest against one another, with the outer chain links enclosing the inner links, creating stable, immovable contact surfaces that are virtually unaffected by wear. This results in mutual support and centering, which highly prevents lateral buckling. All of this is achieved using chain links that can be manufactured in simple U-shapes without any offsets or other complex shaping. Appropriate further training can be found in the subclaims:

[0015] It is advantageous to arrange inner and outer rollers on the pivot pins as engagement elements for the pinion drive. These rollers are adjacent to the legs and plates on each side of the U-shape. This allows the pinion drive to be configured so that two double sprockets engage the inner and outer rollers. This allows very high forces to be transferred from the pinion drive to the chain links.

[0016] In a preferred development, at least one inner roller and preferably at least two inner rollers can be arranged on each joint pin, adjacent to the legs and tabs on each side of the U-shape. Alternatively or additionally, at least one outer roller and preferably at least two outer rollers can be arranged on each joint pin, adjacent to the legs and tabs on each side of the U-shape. In other words, each joint pin can carry a total of at least two or preferably at least four inner rollers and / or a total of at least two or preferably at least four outer rollers, which border the legs and tabs on both sides. By using two inner rollers and two outer rollers on each side of the legs and tabs, this special arrangement of the rollers makes it possible to distribute the force introduction and thus design the geometry accordingly compact.

[0017] A link guide opposite the pinion drive conveniently generates a counterforce that stabilizes the chain in its position.

[0018] In certain sections, usually outside the lifting range, it is advantageous to guide the push chain along guide rails. Such guides can be straight or curved along sections and can be provided both on the force application side and in front of the pinion engagement. Guide rails for the outer rollers are possible, but guide elements arranged at the base of the U-shaped outer and / or inner chain links, which run along guide rails, are also conceivable. Such guide elements and guide rails can, for example, be grooved guides running on both sides of the push chain.

[0019] Before the force is introduced by the pinion drive, such guide rails can be designed as chain storage and can be straight, curved or alternately straight and curved, i.e. meandering.

[0020] To stabilize a load lift, it is advisable for a push chain to work in synchronized fashion with at least one other similar push chain. These two push chains stabilize each other by being able to pivot in opposite directions. A combination of four synchronized push chains can optimally operate a lifting platform or similar device.

[0021] Of course, a push chain can also be used individually, for example, if a load to be moved is also being guided by another means. More than four push chains are also conceivable.

[0022] In a further aspect, a drive device is proposed. The drive device comprises at least one push chain according to one of the embodiments described above or below, and at least one pinion drive. The pinion drive engages the engagement elements of the push chain and is designed to drive the push chain.

[0023] In a further development, inner and outer rollers can be arranged as engagement elements on the pivot pins, adjacent to the legs and plates on each side of the U-shape. The pinion drive can consist of two double sprockets for engagement with the inner and outer rollers.

[0024] In a further aspect, a system is proposed that comprises a lifting platform and a drive device according to one of the embodiments described above or below. The drive device is designed to selectively raise or lower the lifting platform.

[0025] In a further aspect, the use of a push chain and / or a drive device for selectively raising or lowering a lifting platform is proposed.

[0026] The term "push chain," as used here, is a broad term to which its usual and common meaning should be given, as understood by those skilled in the art. The term is not limited to any specific or adapted meaning. The term can, without limitation, refer in particular to a mechanical component of conveyor technology that can be wound up when de-energized, but can transmit thrust and compression forces when under tension. Push chains are important components in linear drive technology. They demonstrate their true strength where other products such as lifting gears are unsuitable due to space constraints. Typically, loads in drive technology are moved by tension or compression. The push chain can move loads by tension and compression. It consists of specially shaped, high-precision, mechanical chain links. The chain links continuously interlock with each other. The push chain can thus pull and "push."

[0027] The term "pinion drive," as used here, is a broad term to which its usual and common meaning should be given, as understood by those skilled in the art. The term is not limited to any specific or adapted meaning. The term can refer, without limitation, in particular to a drive with at least one pinion or sprocket. The pinion drive typically has a drive housing in which the pinion is located, which engages the intermediate links of the linear chain and moves the chain link by link—both forward and backward. The chain itself has two loose ends. The load to be moved is attached to one end. The other end can be guided freely and is usually coiled in a storage unit. This saves an enormous amount of installation space and is the main advantage of the linear chain. If a "normal" screw jack were used, much more installation space would be required for the spindle stroke.A drive element, usually an electric motor, applies thrust to the chain links. The shoulders of the individual chain links then press against each other, forming a rigid unit. This allows them to lift or push the load.

[0028] In summary, without limiting further possible embodiments, the following embodiments are proposed: Embodiment 1: A push chain with chain links that are connected to one another by joints and have stop surfaces, whereby a straight alignment of the chain links occurs when the link is struck, but the chain links are pivotable relative to one another in the other direction, and wherein the chain links have engagement elements for a pinion drive, wherein U-shaped outer chain links and U-shaped inner chain links are arranged in an interlocking manner, wherein the inner chain links rest with their outer sides against the inner sides of the outer chain links, and wherein the chain links have a complete U-shape over half of their longitudinal extent, and over the other half of the longitudinal extent, the legs of the U have longitudinally projecting plates, such that joints are mounted in both the legs and the plates in such a way that each joint movably connects an outer chain link to an inner chain link,and that due to the dimensions of the chain links, these are supported with the stop surfaces on the bases of the U in the extended state of the push chain, and at the same time, all outer chain links and all inner chain links are supported with their respective stop surfaces on the legs of the U on the stop surfaces of the plates of the following chain link. Embodiment 2: Push chain according to embodiment 1, wherein inner rollers and outer rollers are arranged as engagement elements on the joint pins, adjacent to the legs and plates on each side of the U-shape. Embodiment 3: Push chain according to embodiment 2, wherein the pinion drive consists of two double chain wheels for engagement with the inner rollers and the outer rollers. Embodiment 4: Push chain according to embodiment 2 or 3, wherein on each joint pin, adjacent to the legs and plates on each side of the U-shape,at least one inner roller, and preferably at least two inner rollers, and at least one outer roller, and preferably at least two outer rollers, are arranged. Embodiment 5: A push chain according to one of embodiments 1 to 4, wherein a slotted guide is arranged opposite the pinion drive to generate a counterforce. Embodiment 6: A push chain according to one of embodiments 1 to 5, wherein the push chain is guided in partial areas of its movement path by fixed guide rails, which can run straight or curved in the pivoting direction. Embodiment 7: A push chain according to embodiment 6, wherein the guide rails are tracks for the outer rollers. Embodiment 8: A push chain according to embodiment 6, wherein guide elements are arranged at the base of the U-shapes of the outer and / or inner chain links, which guide elements run in guide rails. Embodiment 9: A push chain according to embodiment 8,wherein the guide elements and the guide rails are grooved guides running on both sides of the push chain. Embodiment 10: Push chain according to one of embodiments 6 to 9, wherein guide rails are designed as chain stores before the force is introduced by the pinion drive, which can be straight, curved, or alternately straight and curved. Embodiment 11: Push chain according to one of embodiments 1 to 10, wherein it interacts in a synchronized manner with at least one other similar push chain, wherein these two push chains stabilize each other by being pivotable in opposite directions. Embodiment 12: Push chain according to embodiment 11, wherein four push chains interact in a synchronized manner. Embodiment 13: Drive device comprising at least one push chain according to one of the preceding embodiments and at least one pinion drive,The pinion drive engages the engagement elements of the push chain and is designed to drive the push chain. Embodiment 14: Drive device according to the preceding embodiment, wherein inner rollers and outer rollers are arranged as engagement elements on the hinge pins, adjacent to the legs and plates on each side of the U-shape, wherein the pinion drive consists of two double chain wheels for engaging the inner rollers and the outer rollers. Embodiment 15: System comprising a lifting platform and a drive device according to one of the two preceding embodiments, wherein the drive device is designed to selectively raise or lower the lifting platform. Short description of the characters

[0029] The drawing shows the invention and possible developments thereof. Further details and features emerge from the following description of exemplary embodiments, particularly in conjunction with the subclaims. The respective features can be implemented individually or in combination with one another. The invention is not limited to the exemplary embodiments. The exemplary embodiments are illustrated schematically in the figures. The same reference numerals in the individual figures denote identical or functionally identical elements, or elements corresponding to one another in terms of their functions. They show: Fig. 1 the push chain according to the invention in a perspective view from the side in which the chain links can be pivoted, and Fig. 2 in perspective view from the side on which the stops ensure straight alignment, Fig. 3 the stop surfaces for power transmission through the chain links, Fig. 4 the power transmission through double sprockets, Fig. 5 a push chain with pinion drive, Fig. 6 a design of a guide rail, Fig. 7 a further design of a guide rail Fig. 8 a chain storage unit, Fig. 9 the chain box in a closed state and connected to the pinion drive, Fig. 10 another embodiment of the push chain according to the invention in an interior view, Fig. 11 the push chain of the Fig. 10 in perspective view, Fig. 12 a perspective view of the push chain of the further embodiment of the Fig. 10 and 11 with the pinion drive of a drive device having double chain wheels, Fig. 13 a deflection of a chain box with a closed housing and Fig. 14 the redirection of the chain storage of the Fig. 13 with the case partially opened. Description of the embodiments

[0030] Fig. 1 und Fig. 2 show the push chain 1 according to the invention in a perspective view, wherein Fig. 1 shows the push chain 1 viewed from the side in which the chain links 2, 3 can be pivoted, and Fig. 2 from the side on which the stops ensure straight alignment.

[0031] The push chain 1 consists of U-shaped inner chain links 3, which are encompassed by U-shaped outer chain links 2, with their outer and inner surfaces resting tightly against one another, yet allowing pivoting movement. Both the outer 2 and the inner chain links 3 form a complete U-shape 11, 11' at half their longitudinal extent, to which plates 12 and 13 are attached at the sides of the legs 9, 10 of the U. The joints 4 are mounted both in the legs 9, 10 of the U-shapes 11, 11' and in the plates 12 and 13 attached to them. A joint 4 connects the plates 13 of an outer chain link 2 with the legs 9 of the inner chain link 3. The next joint 4' is the other way around; this connects the plates 12 of the inner chain link 3 with the legs 10 of the next outer chain link 2. This continues along the entire push chain 1. The joints 4, 4' comprise joint pins 14.

[0032] The dimensions of the chain links 2, 3 are such that, when the push chain 1 is stretched, all chain links 2, 3 support each other at the bases of the U with the stop surfaces 5. At the same time, all outer chain links 2 and all inner chain links 3 also support each other with their respective stop surfaces 6 on the legs 9, 10 of the U on the stop surfaces 6' on the plates 12, 13 of the following chain link 2, 3.

[0033] This support is further enhanced by the Fig. 3 , which shows in double hatching the stop surfaces 5 on the bases of the U of both the inner chain links 3 and the outer chain links 2. It can also be seen how all inner chain links 3 and all outer chain links 2 are supported by their stop surfaces 6 on the legs 9, 10 of the U and by their stop surfaces 6' on the plates 12, 13. In this case, the stop surfaces 6 of the legs 10 of the outer chain links 2 always meet the stop surfaces 6' of the plates 13 of the next outer chain links 2 and the stop surfaces 6 of the legs 9 of the inner chain links 3 meet the stop surfaces 6' of the plates 12 of the next inner chain links 3. In this way, a simple support of all chain links 2, 3 by the stop surfaces 5 on the bases of the U-shapes 11, 11' is supplemented by the fact that all inner chain links 3 and all outer chain links 2 are also supported by their stop surfaces 6, 6'.Because the U-shapes are straight without any bending, a high level of rigidity with minimal buckling tendency is achieved for very high forces.

[0034] Fig. 4 shows with the arrows 22 a force introduction to the engagement elements 7, namely the inner rollers 15 and outer rollers 16 of the joints 4, 4', by double chain wheels of a Fig. 4 pinion drive not shown in detail. The inner rollers 15 and outer rollers 16 are arranged adjacent to the legs 9, 10 and tabs 12, 13 on each side of the U-shape. According to the illustration of the Fig. 4 At each end of each pivot pin 14, an inner roller 15 and an outer roller 16 are arranged in such a way that they accommodate the legs 9, 10 and plates 12, 13 between them. Through their engagement with both the inner rollers 15 and the outer rollers 16 on each side of the U-shapes 11, 11' of the inner chain links 3 and outer chain links 2, a balanced force introduction into the push chain 1 is achieved, which - as in Fig. 3 shown - with the stop surfaces 5 and 6, 6' a well-balanced transmission of the introduced force 22 to the following and further chain links 2, 3.

[0035] Fig. 5 shows a push chain 1 with the pinion drive 8 of a drive device comprising double chain wheels. Following the introduction of force 22 by the pinion drive 8, the push chain 1, in a conventional design, is brought into its extended state in which it lifts a load in a vertically aligned manner according to arrow 23. In front of the pinion drive 8 there is a chain storage unit 21, which is shown here without a guide. Such a chain storage unit 21 can be provided according to Fig. 8 with a guide for the outer rollers 16.

[0036] Fig. 6 shows a design for a guide rail 17, which is fixedly mounted in a manner not shown. This guide rail 17 is designed such that it interacts with guide elements 19 that are attached to the bases of the U of the inner chain links 3 and / or outer chain links 2. The guide of the push chain 1 is designed here as grooved guides 20 on both sides.

[0037] Fig. 7 shows a further embodiment of a guide rail 17, which is designed with raceways 24 for guiding the outer rollers 16.

[0038] Fig. 8 shows a chain box 21, which has the outer rollers 16 of a chain box 21 according to Fig. 5 by means of tracks 24 and thus stores the push chain 1 required for possible strokes.

[0039] Fig. 9 shows the chain box 21 in a closed state and connected to the pinion drive 8. As in Fig. 9 As can be seen, the push chain 1 is enclosed on all sides by the chain storage 21.

[0040] Fig. 10 shows a further embodiment of the push chain 1 according to the invention in an internal view. Fig. 11 shows the push chain 1 of the Fig. 10 in perspective view. Only the differences from the previous embodiment are described below, and identical or comparable components are provided with the same reference numerals. Fig. 11

[0041] We in Fig. 10 and 11 As shown, two inner rollers 15 and / or outer rollers 16 can be arranged on each pivot pin 14 adjacent to the legs 9, 10 and tabs 12, 13 on each side of the U-shape. Two outer rollers 16 and one inner roller 15 are shown. However, it is understood that two inner rollers may be provided, or one outer roller 16 and two inner rollers 15.

[0042] Fig. 12 shows a perspective view of the push chain 1 of the further embodiment of the Fig. 10 and 11with the pinion drive 8 of a drive device having double sprockets 25. It can be seen that the pinion drive 8 has a total of two double sprockets 25, which are arranged on a common drive shaft 26 of the pinion drive 8. From each of the double sprockets 25, a pinion or sprocket 27 engages the inner roller(s) 15, and a pinion or sprocket 27 engages the outer roller(s) 16.

[0043] Fig. 13 shows a deflection 28 of a chain storage 21 with a closed housing 29, which supports the outer rollers 16 of the push chain 1 of the further embodiment of the Fig. 10 and 11 by means of at least one deflection track 30 and thus stores the push chain 1 required for possible strokes. Fig. 14 shows the deflection 28 of the chain box 21 of the Fig. 13 with the housing 29 partially open. The deflection 28 allows the push chain to be deflected by 180°. This creates a compact arrangement.

[0044] The push chain 1 and drive device with the pinion drive 8 described herein can be part of a system. The system further comprises a lifting platform. The drive device is designed to selectively raise or lower the lifting platform. In other words, the push chain 1 and / or drive device described herein can be used to selectively raise or lower a lifting platform. Bezugszeichenliste

[0045] 1 Push chain 2, 3 Chain links 2 Outer chain links 3 Inner chain links 4, 4 Joints 5, 6, 6 Stop surfaces 5 Stop surface at the base of the respective U 6 Stop surface on the legs of the U 6 Stop surface on the plates 12, 13 7 Engagement elements 8 Pinion drive 9 Legs of the inner chain links 10 Legs of the outer chain links 11, 11 Complete U-shape 12 Longitudinally projecting plates of the inner chain links 13 Longitudinally projecting plates of the outer chain links 14 Joint pins 15 Inner rollers 16 Outer rollers 17 Guide rails 18 Tracks for outer rollers 19 Guide elements 20 Grooved guides 21 Chain box 22 Arrows: Force introduction through double chain wheels 23 Arrow: Load to be lifted 24 Raceways 25 Double sprocket 26 Drive shaft 27 Pinion or sprocket 28 Deflection 29 Housing 30 Deflection raceway

Claims

1. Thrust chain (1) with chain links (2, 3) connected to each other by joints (4, 4') and having stop surfaces (5, 6, 6'), whereby a straight alignment of the chain links (2, 3) takes place in the case of contact, but the chain links (2, 3) are pivotable in the other direction with respect to each other, and wherein the chain links (2, 3) have engaging elements (7) for a pinion drive (8), characterized in that U-shaped outer chain links (2) and U-shaped inner chain links (3) are arranged in an intermeshing manner, wherein the inner chain links (3) bear with their outer sides against the inner sides of the outer chain links (2), and wherein the chain links (2, 3) have a complete U-shape (11, 11') for half of their longitudinal extent, and for the other half of the longitudinal extent the limbs (9, 10) of the U have plates (12, 13) projecting in the longitudinal direction, in that joints (4, 4') are mounted both in the limbs (9, 10) and in the plates (12, 13) in such a way that each joint (4, 4') movably connects an outer chain link (2) to an inner chain link (3), and in that the dimensions of the chain links (2, 3) support them, in the stretched state of the thrust chain (1) with the stop surfaces (5) on the bases of the U, and simultaneously support all outer chain links (2) and all inner chain links (3) with their respective stop surfaces (6) on the limbs (9, 10) of the U on the stop surfaces (6') of the plates (12, 13) of the subsequent chain link (2, 3).

2. Thrust chain according to Claim 1, characterized in that, as engaging elements (7), inner rollers (15) and outer rollers (16) adjoining the limbs (9, 10) and plates (12, 13) on each side of the U-shape are arranged on the joint pins (14).

3. Thrust chain according to Claim 2, characterized in that the pinion drive (8) consists of two double sprockets for engagement into the inner rollers (15) and into the outer rollers (16).

4. Thrust chain according to Claim 2 or 3, wherein at least one inner roller (15) and preferably at least two inner rollers (15) and at least one outer roller (16) and preferably at least two outer rollers (16) are arranged on each joint pin (14), adjoining the limbs (9, 10) and plates (12, 13) on each side of the U-shape.

5. Thrust chain according to one of Claims 1 to 4, characterized in that a slotted guide lies opposite the pinion drive (8) in order to generate a counterforce.

6. Thrust chain according to one of Claims 1 to 5, characterized in that the thrust chain (1) is guided in part regions of its movement path by fixedly arranged guide rails (17) which can run in a manner which is straight or curved in the direction of rotation.

7. Thrust chain according to Claim 6, characterized in that the guide rails (17) are tracks (18) for the outer rollers (16).

8. Thrust chain according to Claim 6, characterized in that guide elements (19) which run in guide rails (17) are arranged at the base of the U-shapes of the outer and / or inner chain links (2, 3).

9. Thrust chain according to Claim 8, characterized in that the guide elements (19) and the guide rails (17) are groove guides (20) running on both sides of the thrust chain (1).

10. Thrust chain according to one of Claims 6 to 9, characterized in that guide rails (17) are configured as chain boxes (21) before force is applied by the pinion drive (8), which chain boxes can run in a manner which is straight, curved or alternately straight and curved.

11. Thrust chain according to one of Claims 1 to 10, characterized in that it interacts in a synchronized manner with at least one other similar thrust chain (1), wherein these two thrust chains (1) stabilize each other in that they can be pivoted in opposite directions.

12. Thrust chain according to Claim 11, characterized in that four thrust chains (1) interact in a synchronized manner.

13. Drive device, comprising at least one thrust chain (1) according to one of the preceding claims, and at least one pinion drive (8), wherein the pinion drive (8) engages into the engaging elements (7) of the thrust chain (1) and is configured to drive the thrust chain (1) .

14. Drive device according to the preceding claim, wherein, as engaging elements (7), inner rollers (15) and outer rollers (16) adjoining the limbs (9, 10) and plates (12, 13) on each side of the U-shape are arranged on the joint pins (14), wherein the pinion drive (8) consists of two double sprockets for engagement into the inner rollers (15) and into the outer rollers (16).

15. System comprising a lifting platform and a drive device according to either of the two preceding claims, wherein the drive device is configured to optionally lift or lower the lifting platform.