Spatially deflectable cable routing device, particularly for a robot

Description

[0001] The invention generally relates to a cable guide device for dynamically guiding cables, such as cables, hoses, or the like, between two connection points, at least one of which is movable relative to the other. The invention particularly relates to such a cable guide device for use on a robot with multiple degrees of freedom, in particular on an industrial robot or . industrial articulated arm robots .

[0002] In this context, a robot is generally understood to mean any type of handling device that is operated automatically, but in particular industrial articulated-arm robots with multiple degrees of freedom. However, the present invention is not limited to applications with robots, but can also be advantageously used in other ways, for example, with lifting devices or the like.

[0003] The cable routing device serves to protect the routing of cables, particularly supply lines for power, signals, and / or operating media. In an articulated-arm robot, for example, the cables serve to supply the tool mounted on the end effector, also known as the robot hand.

[0004] For the protected routing of cables between two relatively movable connection points, a wide variety of cable routing devices, such as energy chains, are well known.

[0005] The invention particularly relates to a cable guide device which comprises at least one spatially deflectable section along its length.

[0006] Such generic cable guide devices have already been proposed, for example, in patents EP 1 492 967 B1 or EP 1 616 376 B1. Such generic cable guide devices or energy chains comprise a plurality of links that form a receiving space for the protective guidance of the cables. The links are arranged consecutively in a longitudinal direction and are connected to one another in an articulated manner by a respective articulated connection. The articulated connection between two links allows for a spatial deflection of the connected links relative to one another, which is particularly, but not exclusively, necessary for applications on articulated-arm robots or industrial robots.

[0007] Further such cable routing devices are disclosed in DE 20 2018 103418 U1, DE 10 2010 032920 A1, DE 20 2020 100699 U1 and WO 03 / 084721 A2.

[0008] Particularly in such applications, both the distance and the spatial position between the two relatively movable connection points typically change, for example, between the third axis of an articulated-arm robot and the sixth axis or the end effector of an articulated-arm robot. This requires a cable guide length that covers the greatest possible distance and angle of rotation between the connection points. To prevent uncontrolled movements due to the excess length in such applications, depending on the position, so-called retraction systems or retraction systems are already known from the prior art.

[0009] A common design for such retraction systems comprises a longitudinally displaceable deflection pulley around which the cable guide device is guided, forming a loop or deflection curve. The longitudinal adjustment of the deflection pulley retracts or retracts the length of the cable guide device that is not required, depending on the operating position. An example of such a retraction or retrieval system is known from patent EP 3 126 104 B1. However, the design of such systems is comparatively complex and takes up space, which can, among other things, impair the freedom of movement of a robot.

[0010] A simplified solution in this respect for resetting or retrieving spatially deflectable cable guide devices or energy chains was proposed in patent EP 1 200 753 B1. In this case, at least one resilient rod is provided in the receiving space of the cable guide device for resetting purposes. This resilient rod is resilient about its longitudinal axis and extends longitudinally within the receiving space. When the chain links are pivoted, the rod generates a counteracting restoring force. However, this solution also requires a certain amount of installation space or freedom of movement for the movement of the longitudinal section of the cable guide device provided with the resilient rod. Another solution using a spring arm, which also requires installation space, for example around the robot arm, was proposed in DE 20 2006 0066 37 U1.

[0011] In view of the above prior art, a first object of the present invention is to propose a simplified and compact solution that can, in particular but not exclusively, implement the function of a retrieval system. The solution should be particularly suitable for articulated-arm robots.

[0012] A generic cable guide device is used to guide flexible lines, such as cables, hoses, or the like, between a first connection point and a second connection point that is movable relative thereto, particularly on a robot with multiple degrees of freedom. For this purpose, the cable guide device comprises, in particular, a plurality of links that form a receiving space for lines, are arranged consecutively in a longitudinal direction, and are connected to one another in an articulated manner by a respective articulated connection. The articulated connection allows or enables a spatial deflection of the connected links relative to one another.

[0013] According to the invention, the cable guide device or energy guide chain, in the simplest embodiment of the invention, comprises at least one elastic return element and has a variable-length section. Thus, according to the invention, at least the longitudinal section of the cable guide device or energy guide chain is designed such that the length of this longitudinal section is variable. The variable-length section can, in particular, be extendable against a return force caused by the elastic return element.

[0014] In particular, the length-variable section comprises a number of links that are connected to one another so as to be both relatively rotatable in the longitudinal direction and longitudinally adjustable relative to one another to extend the length-variable section in the longitudinal direction. The links can be connected in particular in an articulated manner and / or connected or mechanically coupled in such a way that a longitudinal adjustment of two links relative to one another results in a desired, predetermined relative rotation.

[0015] The return element is intended to be elastically stretchable and arranged in such a way that it exerts a restoring force on the length-variable section, which counteracts an extension of the length-variable section.

[0016] A key idea of ​​the invention is to enable a change in length by combining permitted relative rotation of the links with the adjustability or displacement of the links relative to one another in the longitudinal direction, since the cables to be accommodated are not longitudinally expandable, i.e. they fundamentally do not allow for any lengthening (although the cables themselves are not necessarily the subject of the invention). The invention is based, among other things, on the finding that a helical laying of the cables in the cable guide device allows for stretching within certain limits. This can be exploited by combining permitted relative rotation and longitudinal adjustability between the links in order to create a design that is comparatively easy to stretch or retract in the longitudinal direction, at least in one longitudinal section of the cable guide device.

[0017] In combination with an elastically stretchable return element, a particularly simple, compact and lightweight return functionality can be achieved.

[0018] The spiral or helical course can be predetermined by the links in the length-variable section itself, or, for example, with optional extension by at least one correspondingly deformable support element, e.g. a band-like carrier, with an expandable helical or helical basic shape, on which the lines in the length-variable section are held.

[0019] The connection between the links can be articulated with several degrees of freedom, or can be designed in the form of a screw joint, for example.

[0020] If the length-variable section itself specifies the preferred helical course of the lines, its links are preferably not freely rotatable relative to one another, but only in a correspondingly predetermined manner.

[0021] In particular in such an embodiment, it is advantageous if the connection of successive links of the length-variable section is designed in such a way that a longitudinal adjustment of two links relative to each other, depending on the direction in extension or back into the retracted position, specifies a relative rotation in either one or the opposite direction of rotation about the longitudinal direction.

[0022] The connection between the links in the length-variable section can comprise a type of positive guide, in particular a rotary guide, which, upon lengthening longitudinal adjustment of the two links, causes their relative rotation, i.e. of one link relative to the other, in a first direction of rotation and, conversely, upon restoring longitudinal adjustment of the two links, causes their opposite relative rotation. If no spatial deflectability is required in the length-variable section, this can be achieved, for example, by a screw joint for connecting the links. However, connection types or joint types with additional degrees of freedom are preferred, which allow at least a slight spatial deflection between the links of the length-variable section, in particular at least about two axes perpendicular to the longitudinal direction.

[0023] In a preferred embodiment, the length-variable section has a first section in which connected links rotate relatively in a first direction of rotation upon extension and relatively in the opposite direction of rotation upon return, as well as a second section in which connected links rotate relatively in a second direction of rotation upon extension, which is opposite or contrary to the first direction of rotation, and relatively in the opposite direction of rotation upon return. The relative rotation here refers to two connected consecutive links, regardless of the rotating link, i.e. one link rotates relative to the other. Preferably, therefore, in each section in the extension or deployment direction (when extended), only one predetermined direction of rotation is permitted or effected, and in the return direction only the opposite direction of rotation, i.e.Depending on whether the variable-length section is being pulled apart or contracted again, the relative rotation occurs in one direction or the other. This ensures that helical cables are reliably moved back and forth between two opposing spiral shapes, preventing excessive stress.

[0024] Particularly preferably, the return element is arranged to exert a prestress in the longitudinal direction, in particular a prestress that can be adjusted as required, in order to always contract the variable-length section into a basic position that corresponds to the smallest possible longitudinal dimension, even in the case of relatively stiff cables. d.h. allows maximum extension from this basic position. The return element thus reliably ensures retraction to the shortest retracted position.

[0025] The at least one elastic return element can be designed, in particular, as a rope or band. A rubber cable, preferably with rubber threads and / or rubber bands and a braid, can be used as the return element. Alternatively, a suitable spiral spring, for example, can also be provided as the return element.

[0026] In a further development, an adjusting device for adjusting the pretension of the return element is provided on at least one end region of the length-variable section, in particular on an end member of the length-variable section.

[0027] To minimize the stress on the cables, especially when using two counter-rotatable sections, a center piece can be provided between two sections of the variable-length section, providing strain relief for the cables to be routed. The center piece preferably has a greater overall length than the overall length or division of the number of links of the variable-length section.

[0028] Such a middle section can be connected, in particular at its longitudinal ends, to the counter-rotating sections, e.g. by means of counter-rotating guides or, if necessary, also in a rotationally fixed manner.

[0029] Particularly preferred, especially in the case of a rope-like return element, at least the links of the variable-length section each have a central core with a central through-hole through which the elastic return element is freely guided with clearance. This allows the elastic return element to be arranged on the neutral axis of the cable guide. The return element is preferably guided through the core with clearance, ensuring low friction and low wear.

[0030] A central core is not absolutely necessary if, for example, the sections are connected via tubular sheath sections. However, the design with a central core is particularly preferred, for example, if the variable-length section itself determines the desired routing of the cables – without additional support components for the cables.

[0031] A central core can preferably comprise or form guide elements of the rotary guide and / or, preferably, can provide a direction-dependent relative rotation in one or the opposite direction of rotation about the longitudinal direction during longitudinal adjustment of two links. The core can, for example, form the joint parts of a screw joint or a more complex joint with more degrees of freedom on both sides. Alternatively, the desired relative rotation can also be achieved via radially outer guide parts, e.g., a rotary guide, on the shell parts of the links.

[0032] It is preferably provided that at least the links of the length-variable section or of each sub-section, or even all links, each have a central core which forms a joint head and a joint receptacle opposite in the longitudinal direction, which is designed to correspond to the joint head of the following link for the articulated connection.

[0033] The joint head and joint socket preferably simultaneously form the rotational guide for specifying a specified or desired relative rotation, in particular through one or more helical guide surfaces, e.g., with helical trough-like depressions, on the inside of the joint socket. Thus, the joint head and joint socket can interact with one or more guide elements on the joint head to specify the relative rotation.

[0034] Different shapes of joint head and interacting joint receptacle are within the scope of the invention.

[0035] In one variant, it is provided that the joint head has a basic shape with a substantially triangular cross-section, preferably with arched rounded sides, the three vertices of which are guided as guide elements on corresponding helically extending guide surfaces on the inside of the joint receptacle.

[0036] In another variant, it is provided that the joint head has a basic shape with a substantially elliptical cross-section, the two main vertices of which are guided as guide elements on corresponding helically extending guide surfaces on the inside of the joint receptacle.

[0037] In principle, with a suitable design, the joint head and joint socket can form a joint connection that is longitudinally adjustable, relatively rotatable, and pivotable about at least two axes perpendicular to the longitudinal direction for spatial deflection of the connected links relative to one another. In particular, the sides of the basic shape of the joint head are concave in longitudinal section, in particular corresponding to a radius of curvature for spatial deflection. The joint head and joint socket can interact in a manner similar to the effect of a ball joint.

[0038] To facilitate assembly and improve the manufacturability of the links according to the invention, particularly using plastic injection molding technology, the joint head and joint receptacle are preferably formed by two separate plastic components. This can be achieved in particular by a two-part construction of the core, e.g., with two joinable, complementary injection-molded parts, which are preferably connectable at an interface plane located on the longitudinal axis. In this way, the complex geometry of the receptacle, particularly for implementing the desired rotational-translational-relative adjustment, can be produced more easily and more cost-effectively using injection molding technology. The complementary core parts can be connected in a form-fitting and / or force-fitting manner.

[0039] To facilitate assembly or adjustability of the direction of rotation, the joint receptacle itself can also be formed by at least two separate insert parts which are fastened in a receptacle on the core, each insert part preferably having a helically extending inner surface.

[0040] At least the links of the variable-length section or of its subsections or all of the links preferably each have a central core with at least two essentially radial webs, each of which holds at least one jacket segment. The jacket segments serve to delimit the receiving space in the radial direction, with the jacket segments preferably being arranged so as to be pivotable and / or flexible and forming an insertion opening between each two jacket segments. This facilitates the assembly or replacement of the lines if necessary. At least in the variable-length section, the jacket segments can optionally form a tube that is closed circumferentially and longitudinally. With such a design, the connection of successive links can comprise a rotary guide on the jacket segments, in particular with obliquely running grooves and projections engaging therein at overlapping areas of the jacket segments.

[0041] In one variant, the longitudinally adjustable connection comprises at least two longitudinal stops, which limit the longitudinal adjustment of two links in both directions. Corresponding longitudinal stops can be provided on the core and / or on the casing segments. Particularly preferably, both longitudinal stops for limiting the extension or retraction are formed by a joint mount on the core. This means that no design measures are required on the casing segments.

[0042] The longitudinal play or axial adjustment dimension of the longitudinally adjustable connection between adjacent links is preferably at least 20%, preferably at least 30% and in particular up to 45% of the link pitch or axial length of the link, in particular of the central core.

[0043] Depending on the desired properties, the cable guide device can be designed in such a way that the plurality of links which are connected in a spatially deflectable manner are designed differently from the number of links in the length-variable section, in particular not longitudinally adjustable, i.e. not adjustable or extendable relative to one another in the direction of tensile force transmission (tensile strength) or with an unchangeable length along the neutral fiber.

[0044] Thus, spatially deflectable members of a first type, in particular of a known design, which are not longitudinally adjustable relative to one another, can be connected to members of a second type designed according to the invention, which are provided in the length-variable section, to form a cable guide device.

[0045] Links designed according to the invention differ in particular from spatially deflectable links of a known design in particular by the type of connection, in particular the articulated connection, with which they are connected to one another in pairs, and can, apart from that, have a comparable or essentially identical design to the known one, e.g. with regard to the circumferential limitation by a casing part or the like.

[0046] In a preferred embodiment, the longitudinal section with length-adjustable members designed according to the invention is connected to at least one tensile-strength longitudinal section that is not longitudinally variable and consists of spatially deflectable members of a different type. The length-adjustable section can be provided, for example, between two such longitudinal sections that are not longitudinally variable.

[0047] Alternatively, depending on the application, all elements of the cable guide system can be designed to be spatially deflectable, longitudinally adjustable, and rotatable relative to each other. The entire cable guide system can consist of elements that are connected in a way that allows for spatial deflection and also allows for variable length adjustment.

[0048] The links can be constructed essentially identically in the oppositely rotatable sections, except for the different directions of rotation in the preferred articulated connection, and can be connected via an additional center piece.

[0049] In use, the cable guide device typically has at least one cable guided therein, wherein the at least one cable is arranged in a helical or helix-like manner in the length-variable section, in particular corresponding to a first helical coil in the first subsection and a second helical coil running in the opposite direction of rotation in the second subsection.

[0050] The invention further relates to a robot, in particular an industrial articulated arm robot, with a cable guiding device according to one of the designs described above.

[0051] The invention can be used for any type of supply lines, such as cables, hoses or the like, in particular for power and data supply lines but also compressed air hoses and the like.

[0052] Further details, features, and advantages of the invention will become apparent from the following detailed description of preferred embodiments with reference to the accompanying drawings. FIG.1A-1D : Side views and perspective views of an articulated arm robot with a cable guiding device according to the invention, in a first position ( FIG.1A-1B ), in which the cable guide device is retracted or withdrawn, and a second position ( FIG.1C-1D ), in which the cable guide device is extended; FIG.2A-FIG.2E: Views of a first embodiment of a chain link according to the invention for an extendable cable guide device; FIG.3A-3D: an extendable, length-variable section with a purely exemplary number of links according to FIG.2A-2E, in a retracted state, in longitudinal section ( FIG.3A ) and in front view ( FIG.3B ), as well as in an extended, elongated state, in longitudinal section ( FIG.3C ) and in front view (FIG.3D), with an elastic return element for returning to the retracted state; FIG.4 : a schematic representation of the cable behavior or the helical cable path of cables guided in a cable guide device according to the invention in a retracted state and in an extended state; and FIG.5A-5B : a particularly preferred arrangement with an extendable, length-variable section with two counter-rotating sections made of links according to FIG.2A-2E; FIG.6A-6G : Views of a second embodiment of an extendable longitudinal section of a cable guide device: in retracted ( FIG.6A, 6C ) and extended state ( FIG.6B, 6D ) of the longitudinal section, as well as a side view of the route of the cables routed therein: in fully retracted state ( FIG.6E ), in half-extended position ( FIG.6F ) and when fully extended ( FIG.6G ) with percentage indication of an achievable change in length; FIG.7A - FIG.7D : Views of two chain links of the second embodiment, in perspective views ( FIG.7A, 7B ), as well as in exploded views with a chain link for right-handed connection ( FIG.7C ) and a chain link for left-handed connection ( FIG.7D ); FIG.8 : an embodiment of a center piece for connecting counter-rotating sections of chain links according to FIG.7C or FIG.7D ; FIG.9 : an embodiment of an end piece or connecting piece for connecting chain links according to FIG.7A-7D with a conventional chain link; FIG.10A - FIG.10B : Perspective views of a chain link according to a third embodiment of the invention as a variant of FIG.7 , e.g. for larger diameters; FIG.11 : a perspective view of a chain link according to a fourth embodiment of the invention; FIG.12A-12C : Perspective views of a chain link according to a fifth embodiment of the invention, as a variant of FIG.2 , with two interchangeable multi-part inserts of a joint holder ( FIG.12D, FIG.12E ), which can be selected to have one of two opposite directions of rotation; and FIG.13A-13B : a perspective view of a chain link according to a sixth embodiment of the invention, as a variant of FIG.2 .

[0053] FIG.1A-1D show, as an example of an industrial robot, an articulated arm robot 1, here with serial kinematics, e.g., a 6-axis articulated arm robot of a conventional design. The invention is particularly, but not exclusively, advantageously applicable to such robot arms with multiple degrees of freedom. A cable guide device 10 is arranged between two connection points 2, 3, here, e.g., on the third and sixth axes, wherein the cable guide device 10 is fixed at the ends to both connection points 2, 3 on the articulated arm robot 1 by means of clamps. The connection point 3 is spatially movable relative to the connection point 2 in accordance with the robot axes (fourth to sixth axes).

[0054] The cable routing device 10 has, as FIG.1A shows at least one first section 11 of variable length, to which a spatially deflectable second section 12 adjoins. The sections 11, 12 can each be spatially deflectable and of variable length. Alternatively, only the first section 11 can be variable in length and, if necessary, also spatially deflectable, whereas the second section 12 can have known chain links. The second section 12 can, for example, have chain links according to a design from EP1616376B1 or US7439446B2 (=WO2004 / 093279A1, the teaching of which is incorporated herein by reference) or can be composed of such known chain links.

[0055] The connection between the first section 11 and the second section 12 ( FIG.1A ) can be achieved using a special connecting piece or end piece, as described below.

[0056] FIG.2A-FIG.2E show a first example of a chain link 200 for forming a length-variable section 11. In a construction known per se, the chain link 200 comprises a casing 201, which in this example is circumferentially closed around the longitudinal axis L. The casing 201 is connected to a core 210 of the chain link 200 via three radial webs 202 and can, for example, be made in one piece from plastic. Between the casing 201 and core 210, the chain link 200 forms three chambers 203, separated by the webs 202, as receiving space for cables (not shown). The chambers are continuously open in the axial direction. The casing 201 and webs 202 are arranged and designed, for example, rotationally symmetrical about the longitudinal axis L.

[0057] A particular aspect of the invention lies in the design of the connection between successive chain links 200, as can be seen from FIG.3A-3C illustrated by an exemplary section of chain links 200. To connect adjacent chain links 200, the core 210 has a joint head 220 at one longitudinal end and a joint receptacle 230 conjugated thereto at the other longitudinal end. The joint head 220 and the joint receptacle 230 are designed such that connected chain links 200 are longitudinally adjustable relative to one another, as a comparison between FIG.3A und FIG.3C shows, and in such a way that a longitudinal adjustment of two chain links 200 to each other causes their relative rotation by a predetermined angular dimension, as can be seen from the front views in FIG.3B or FIG.3D.

[0058] The best from FIG.2A-2B and FIG.2E, has in this example a basic shape with a substantially triangular cross-section perpendicular to the longitudinal axis L, wherein in this cross-section the sides 221 are rounded in an arcuate manner according to a first radius, cf. FIG.3B , and the vertices 222 or tips are rounded according to a significantly smaller second radius, see FIG.3D. In each longitudinal section along the longitudinal axis, the outer surface of the arcuate triangular joint head 220 is further rounded according to a comparatively small, third radius, ie this rounding is provided circumferentially as FIG.2A with FIG. 2E. Thus, only a curved contact corresponding to the contour of the largest cross-sectional area can be achieved in the joint receptacle 230, whereby the rounding in the axial direction or corresponding to the third radius allows tilting or a ball-joint-like movement about two axes perpendicular to the longitudinal axis. The joint head 220 is integrally connected to the wall of the joint receptacle 230 via a neck-like pin 223.

[0059] FIG.3A und FIG.3C further show a restoring element 300 in the form of an expander rope or rope-like rubber cable. This preferably consists of highly elastic rubber threads and a braiding for their protection. The restoring element 300 is guided coaxially to the longitudinal axis L through corresponding central through-openings 225 in the core 210 and is fastened to the ends of the length-variable section 11 on the chain links 200 in a tension-resistant manner, e.g. by means of clamping rings 302. The restoring element 300 is elastically longitudinally extensible as intended and generates an axially directed restoring force on the length-variable section 11, which counteracts an extension of the length-variable section, ie, the section from the extended position to FIG.3C into the retracted position in FIG.3A resets.

[0060] The joint head 220 of each connection between two chain links 200 interacts with the inner surface 232 of the joint receptacle 230 in such a way that the connection acts as a rotary guide or forced guide, which, when extended longitudinally ( FIG.3A to FIG.3C ) the chain links 200 rotate relative to one another in a first rotational direction, causing their opposite relative rotation upon restoring longitudinal adjustment. For this purpose, the joint receptacle 230 is provided with an inner surface 232, which corresponds to a helical rotation of the outer contour of the joint head 220. In other words, the inner surface 232 corresponds to a surface generated by rotation of the contour of the joint head 220 during axial advance. Accordingly, the joint receptacle 230 forms a negative shape for the rotatable and longitudinally adjustable mounting of the joint head 220, in particular conjugated to the volume generated by the corresponding rotational translation of the joint head 220, plus a technically necessary movement play.Thus, the three vertices 222 of the joint head 220 are guided as guide elements on corresponding helically extending guide surfaces, which form trough-like and helical depressions, similar to a type of internal thread, on the inside of the joint receptacle 230. The chain links 200 are connected or coupled in such a way that a longitudinal adjustment of two links relative to each other causes their relative rotation, depending on retraction or extension in one or the other direction of rotation.

[0061] As longitudinal stops to limit the maximum expansion or extension, the sheaths 201 each engage with each other in the plugged-in position. For this purpose, the sheath 201 has a circumferential annular groove with a rear annular edge 205 as a stop and an inwardly projecting annular collar 207, which abuts the edge 205 as a counter-stop. Longitudinal stops are preferred, among other things, because the return element 300 clamps the chain links 200 against each other, but a breakage of the return element 300 should not result in the separation of the variable-length section 11 of the cable guide device or energy chain 10. The longitudinal stops can also be implemented differently, e.g., on the central core (see below).

[0062] FIG.4 schematically illustrates two different helical or helix-like courses S1 and S2 of a cable that is guided in a variable-length section. Position S1 corresponds to the retracted or retracted position of the cable guide device 10 (cf. FIG.1A-1B ). Position S2 corresponds to the extended position of the cable guide device 10 (cf. FIG.1C-1D ).

[0063] FIG.5A-5B illustrate a particularly preferred embodiment, wherein the length-variable section 11 has a first subsection 11A, in which connected chain links 200A each rotate relatively in a first rotational direction R1 about the longitudinal direction L upon extension and rotate relatively in the opposite direction R2 upon return. Furthermore, the length-variable section has a second subsection 11B, in which connected chain links 200B rotate relatively in the second rotational direction R2, opposite to the first rotational direction R1, upon extension and rotate relatively opposite to the first rotational direction R1 upon return. As a result, the rotations of the subsections 11A, 11B cancel each other out, so that overall no rotation is transmitted at the ends of the length-variable section 11, and the cables are also protected. The number of links 200A, 200B is preferably the same in both subsections 11A, 11B.The design of the links 200A, 200B of each section 11A, 11B differs only in the direction of rotation, which is determined by the respective joint receptacle 230, i.e., the joint receptacles 230 are reversed. Thus, in one section 11A, the links rotate clockwise relative to each other when extended or pulled out (e.g., R1), and in the other section 11B, they rotate counterclockwise relative to each other when extended (e.g., R2), or vice versa, and rotate back in the opposite direction when retracted.

[0064] Furthermore, a special center piece 250 is provided between the sections 11A, 11B of the variable-length section. The center piece 250 provides strain relief for the cables to be routed, e.g., by means of corresponding slots in the sheath. The center piece 250 preferably has a greater overall length than the overall length or pitch of the sections 200A, 200B.

[0065] The center piece 250 may have a core 252 which is configured at its longitudinal ends corresponding to the links 200A, 200B and is connected to the counter-rotating sections 11A, 11B.

[0066] The permissible relative adjustment dimension between two links 200A or 200B in the longitudinal direction, which is allowed as play for the longitudinally adjustable connection, is in FIG.5B denoted by d, and is summed over all chain links of the length-variable section 11 to the maximum length difference L2-L1 in the fully stretched position ( FIG.5B ).

[0067] A further preferred embodiment will now be described with reference to the FIG.6-9 explained in more detail.

[0068] FIG.6A-6D show a length-variable section 11 of a cable guide device 10 for an arrangement according to FIG.1A , consisting of two sections 11A, 11B. The sections 11A, 11B also rotate in opposite directions to each other when extending from the fully retracted state with length L1 ( FIG.6A, FIG.6C ) to the fully extended state with length L2 ( FIG.6B, FIG.6D ), e.g. with 1.3*L1 ≤ L2 ≤ 1.5*L1, for example with L2=140%*L1 ( FIG.6G ). The sections 11A, 11B are made of connected chain links 700A and 700B respectively according to FIG.7A-7D assembled and connected via a special center piece 800 according to FIG.8 connected to each other, on which guided cables 60 are strain-relieved. At the end, each section 11A, 11B has a special end piece 900 for connecting to a longitudinal section of conventional chain links, e.g. according to the design of EP1616376B1 or US7439446B2 (=WO2004 / 093279A1. As described above and in FIG.6A-6D As illustrated, the two sections 11A, 11B can also be extended or telescopically by rotating in opposite directions, to the left or right, relative to each other.

[0069] FIG.6E-6G show an exemplary arrangement and the course of, for example, six guided lines 60 in section 11. Each line runs in the variable-length section 11 in a helical or helix-like manner, namely corresponding to a first helical coil 61A, e.g., right-handed R1, in the first section 11A and a second helical coil 61B running in the opposite direction of rotation, e.g., left-handed, in the second section 61B. All lines 60 are twisted together to form corresponding multiple-helical packages in the fully retracted state, and in a central region on the middle piece 800 according to FIG.8 strain-relieved. The directions of rotation of the screw coils 61A, 61B correspond to the direction of rotation of the chain links 700A, 700B and are opposite to each other. In the fully extended state ( FIG.6G ), the lines 60 then extend essentially in a straight line, ie both helical coils 61A, 61B are unwound. For this purpose, the partial sections 11A, 11B, when fully extended, form straight, continuous receptacles for the lines 60, cf. FIG.6D .

[0070] FIG.7A-7D show in detail the second example of the chain links 700A, 700B for forming a length-variable section 11 with counter-twisting sections 11A, 11B. For the sake of shortening, only essential differences to FIG.2-5 The chain links 700A, 700B have curved shell segments 71, which are made of identical parts ( FIG.7C-7D ) are manufactured. The shell segments 71 are in FIG.7A-7D not circumferentially closed around the longitudinal axis L, but form an insertion opening 71A, 71B on both sides to facilitate assembly or replacement of the cables 60. Each of the two jacket segments 71 is connected to a core 710 of the chain link 700A, 700B via exactly one radial web 72. Each chain link 700A, 700B thus forms two separate axially open chambers for accommodating the cables 60 (cf. FIG.6D ).

[0071] Each chain link 700A, 700B has a core 710 with a joint head 720 at one longitudinal end, which is axially opposite to it, and a joint receptacle 730A or 730B, which is conjugated thereto, at the other longitudinal end. For easier production, in particular the complex geometry of the joint receptacle 730A or 730B, as well as for simplified assembly of the joint head 720 in the joint receptacle 730, the core 710 is FIG.7A-7D manufactured in two parts, here from a first part 710A comprising the joint head 720 and from a cover-like second part 710B for forming the joint receptacle 730A or 730B. The second part 710B is complementary to the first part 710A and can be connected to it in a form-fitting manner. The two-part construction enables, among other things, a circumferential holding edge 733 at the opening of each joint receptacle 730A or 730B for the engagement of the joint head 720. The holding edge 733 serves in particular as an axial stop during extension or lengthening, but can also limit the spatial deflectability by striking the cylindrical neck which carries the engaging joint head 720. In the opposite direction when retracting, the joint head 720 strikes the inside against the inner surface of the joint receptacle 730A or 730B.

[0072] How FIG.7C-7D As can be seen, due to the design of the webs 72, a stable securing of the second part 710B to the first part 710A is realized. This is achieved by both parts 710A, 710B each jointly having a shaft, pin or the like. z.B. a square, consisting of two halves 711, onto which a conjugated receptacle 712, z.B. a square socket, is inserted. The two halves 711 are secured together when attaching the casing segments 71 by inserting them into the socket 712, whereby each casing segment 71, z.B. by means of a self-tapping screw to the core 710. The receptacle 712 is realized in an inner projection that is integral with the shell segment 71, which then firmly holds and secures the components 710A, 710B of the core 710. Furthermore, FIG.7A-7D also in the first part 710A the coaxial continuously open through-opening 725 for a return element 300 (cf. FIG.5A-5B ), whose mouths gently widen.

[0073] As a comparison of FIG.7C with FIG.7D shows, the chain links 700A, 700B differ in the direction of rotation of the respective joint receptacle 730A or 730B, which is designed either clockwise R1 or counterclockwise R2, whereby the joint head 720 remains the same in each case. Joint head 720 and joint receptacles 730A or 730B allow the desired axial longitudinal adjustment relative to each other and also specify the desired relative rotation. For this purpose, the inner surface of the joint receptacles 730A, 730B and the joint head 720 also interact in this embodiment such that the connection serves as a type of rotational guide or forced guide, which specifies a rotation of the two connected chain links 700A, 700B upon extension or retraction. The joint head in FIG.7A-7D is designed here with an approximately triangular basic shape corresponding to that in FIG.2E.

[0074] FIG.8 shows a construction for a middle piece 800 for connecting the sections 11A, 11B, ie of their end chain links 700A and 700B in the middle area of ​​the variable-length section 11 between the sections 11A, 11B ( FIG.6B-6C ). The basic construction is analogous to FIG.7A-7D , in particular with a two-part core 810 consisting of a first part 810A and a second part 810B, which are secured to one another by means of several, here four identical, shell segments 71, e.g. as shown in FIG.7C-7D described above. The core 810 has or forms at each of its two longitudinal ends one of the two complementary joint receptacles 730A and 730B, respectively, for connection to the joint head 720 of the connected chain link 700A and 700B, respectively. Thus, compared to a simpler, rigid connection of the subsections 11A, 11B, the extension length L2-L1 is increased.

[0075] The center piece 800 further has strain relief elements 840 that are attached to the core 810 on both sides, e.g., in this case, by screwing in a form-fitting and friction-locking manner. Each strain relief element 840 has several T-shaped holders projecting axially on both sides for securing and strain-relieving the cables, e.g., by means of cable ties, on the center piece 800. The strain relief elements 840 can be screwed together as two clamp-like identical parts and encompass the core 810, simultaneously providing additional security for its components 810A, 810B. The center piece 800 shown consists, excluding screws, of only four components: the components 810A, 810B of the core 810, two pairs of sheath segments 71 and two strain relief elements 840. These components, as well as the parts of the links 700A, 700B, are preferably manufactured as plastic injection-molded parts. FIG.8 also illustrates the through-opening 825 in the middle piece 800, for the rope-shaped return element 300 (not shown in FIG.6-9 ).

[0076] FIG.9 shows an end piece 900 for connecting each longitudinal end of the variable-length section 11 comprising the chain links 700A or 700B to the joint socket of a conventional chain link in the design of EP1616376B1 or US7439446B2 (=WO2004 / 093279A1), the teachings of which are incorporated herein by reference. For this purpose, the core 910, consisting of two components 910A, 910B, has a joint head 720 at one axial end for connection to a joint receptacle 730A or 730B of a chain link 700A or 700B, respectively, and a known spherical joint head 90 according to EP1616376B1 or US7439446B2 (=WO2004 / 093279A1) at the other axial end. If necessary, identical end pieces 900 can be used at both ends of the variable-length section 11. Furthermore, the end piece 900 forms coaxial clamping shells 927 of a cable clamp with transverse ribs on the inside of the components 910A, 910B for the axial end fastening of the cable-like return element 300.Thus, the end piece 900 can simultaneously secure the ends of the return element 300 (not shown) without additional clamping rings, as in . FIG.5A-5B As with the clamping rings 302, the preload of the return element 300 can also be adjusted using the cable clamp formed by the clamping shells 927, by preloading it accordingly and then axially securing it to the end piece 900. For this purpose, the combination with clamp-like strain relief elements 840 is advantageous, which, by means of the screw connection, can clamp the components 910A, 910B against each other as tensioning clamps. Accordingly, the two clamp-like strain relief elements 840 preferably also encompass the two clamping shells 927.

[0077] FIG.10A-10B show a further chain link 100 for a length-variable section 11 according to FIG.1A . This variant differs from the previous examples in the elliptical basic shape of the joint head 120 and the corresponding design of the joint socket 130 (only one of the two is shown here). FIG.10B an alternative to securing a multi-part core 110 made up of two parts 110A, 110B by a snap connection of arm-shaped projections 111 on both sides of the parts 110A, 110B in corresponding receptacles 112 in the shell segments 71, which otherwise e.g. FIG.7-9 are equivalent to.

[0078] A similar variant shows FIG.11 , but here for the realization of a tubular, circumferentially closed cable guide device 10. Here, the chain link 1100 is essentially formed from two molded parts 1100A, 1100B, which are connected to one another via a tongue and groove connection at the interface of the webs and are secured by additional securing elements 1111. The other construction can correspond to one of the previous embodiments, in particular with regard to the articulated connection of the chain links 1100.

[0079] FIG.12A-12E show another chain link 1200 with two interchangeable multi-part inserts 1250A, 1250B and a joint holder 1230A or 1230B ( FIG.12D, FIG.12E ) for the rod end 1220 (here as in FIG.7 ), which selectably specify one of two opposite directions of rotation R1, R2. The inserts 1250A, 1250B are multi-part, here for example each made of three individual parts, preferably injection-molded parts in the form of sectors of a ring. The inserts 1250A, 1250B can be snapped into a holder 1260 in the core of the chain link 1200 by axial insertion. The multi-part design can considerably simplify production by injection molding, particularly if the main body of the chain link 1200 is to be manufactured in one piece. Each of the two inserts 1250A, 1250B forms one of the two holders 1230A, 1230B for the opposite relative rotation, clockwise or anticlockwise, for the respective section 11A, 11B. By means of the locking in the axial direction, a joint head 1220 with an insert 1250A, 1250B mounted thereon can be inserted axially into the holder 1260 in the core of the adjacent chain link 1200, which can simplify the assembly.Otherwise, the construction is largely similar to FIG.2A-2E, including three radial webs 1202, which connect a circumferentially closed shell 1201 to the core 1210.

[0080] FIG.13A-13B finally show a variant of a chain link 1300 after FIG.2-3 , in which the desired relative rotation is realized via radially outer guide parts, here outer rotary guide projections 1320 and inner rotary guide recesses 1330, similar to screw threads, on the casing parts of the chain link 1300. The rotary guide recesses 1330 or rotary guide projections 1320 can be designed as obliquely or helically extending grooves and projections engaging therein at overlapping areas of the casing segments.

[0081] Axial stops can be used, as in FIG.2-3 , also be implemented on the casing parts. The chain links 1300 therefore do not have a joint head or joint socket on the core, unlike, for example, FIG.2-3 .

[0082] As the exemplary embodiments show, the length-variable section 11 can be realized by links of different designs, which are connected in pairs so that they can rotate relative to one another about the longitudinal direction L and are longitudinally adjustable relative to one another. The return element 300 can also be realized in various ways and does not necessarily have to be coaxial with the longitudinal direction or provided as an expander cable. LIST OF REFERENCE SYMBOLS

[0083] FIG. 1A-1D 1 Industrial robot 2, 3 Connection points 10 Cable guide device 11 Length-variable section 12 Spatially deflectable section FIG.2A-2E, FIG.3A-3C, FIG.4 200 Chain link 201 Cover 202 Web 203 Chamber / receiving space 205 Edge (stop) 207 Annular collar (stop) 210 Core 220 Rod end 221 Sides (rod end) 222 Crown / tips 223 Pin 225 Through openings 230 Joint receptacle 232 Inner surface (joint receptacle) 300 Return element 302 Clamping ring L Longitudinal axis S1, S2 helical courses FIG.5A-5B 11A first section 11B second section 200A, 200B chain links 250 middle section d axial play / relative adjustment dimension R1, R2 direction of rotation / sense of rotation L1 length retracted L2 length extended FIG.6A-6G , FIG.7A-7D , FIG.8-9 11 variable-length section 11A first sub-section 11B second sub-section 60 cable 71 sheath segment 71A, 71B insertion opening 72 web 90 joint head (conventional) 61A, 61B screw coil / helical course 700A; 700B chain links 710 core 710A, 710B core parts 711 half (safety shaft) 712 holder 720 joint head 725 through-opening 730A; 730B Joint holder 733 Holding edge (axial stop) 800 Middle piece 810 Core (middle piece) 810A, 810B Core parts 825 Through holes 840 Strain relief element 900 End piece 910 Core (end piece) 910A, 910B Components 927 Clamping shell (rope clamp) R1, R2 Direction of rotation / rotation L1 / L2 Length retracted / extended FIG.10A-10B, FIG.11 100 Chain link; 110 Core; 110A, 110B Core parts; 120 Rod end (elliptical); 130 Joint socket 1100 Chain link; 1100A, 1100B Molded parts; 1111 Securing element FIG.12A-12E 1200 Chain link; 1201 Cover; 1202 Link; 1210 Core; 1220 Rod end; 1230A, 1230B Joint socket; 1250A, 1250B Inserts (for joint socket); 1260 Socket (for inserts) FIG.13A-13B 1300 Chain link; 1320 Rotary guide projection; 1330 Rotary guide recess;

Claims

1. A line guide apparatus (10) for guiding lines, such as cables, hoses or the like, between a first and a second connection point (2, 3) movable relative to the first, in particular on a robot (1) with multiple degrees of freedom, comprising: a plurality of links, which form an accommodation space for lines, are arranged successively in a longitudinal direction (L) and are connected together in articulated manner by a respective articulated connection, wherein the articulated connection allows three-dimensional deflection of the connected links relative to one another; and at least one elastic return element (300); characterized in that the line guide apparatus has a portion (11) of variable length, which comprises a number of links (200A, 200B; 700A, 700B) which are connected together so as to be relatively rotatable relative to one another about the longitudinal direction and longitudinally adjustable relative to one another for elongation of the variable-length portion (11) in the longitudinal direction (L), and in that the return element (300) is elastically longitudinally expandable and arranged in such a way that it exerts a return force on the variable-length portion (11), which counteracts elongation of the variable-length portion.

2. The line guide apparatus according to Claim 1, characterized in that at least the number of links (200A, 200B; 700A, 700B) of the variable-length portion (11) are articulately connected and / or in particular are connected or couplable in such a way that longitudinal adjustment of two links (200A, 200B; 700A, 700B) relative to one another brings about relative rotation (R1, R2) thereof.

3. The line guide apparatus according to Claim 2, characterized in that the connection of in each case successive links (200A, 200B; 700A, 700B) of the variable-length portion (11) is configured such that longitudinal adjustment of two links relative to one another predetermines as a function of direction a relative rotation in the one or the opposing direction of rotation about the longitudinal direction (L); wherein the connection in particular comprises a rotary guide, which, on elongating longitudinal adjustment of the two links (200A, 200B; 700A, 700B), brings about relative rotation thereof in a first direction of rotation (R1) and, on return longitudinal adjustment of the two links, brings about opposing relative rotation thereof.

4. The line guide apparatus according to Claim 2 or 3, in particular according to Claim 3, characterized in that the variable-length portion has a first sub-portion (11A), in which connected links (200A; 700A) in each case rotate in relative manner on elongation in a first direction of rotation (R1), and a second sub-portion (11B), in which connected links (200B; 700B) rotate in relative manner on elongation in a second direction of rotation (R2), which is the opposite direction to the first direction of rotation.

5. The line guide apparatus according to one of the preceding claims, characterized in that - the at least one return element (300) is arranged to exert pretensioning in the longitudinal direction, which pretensioning contracts the variable-length portion; and / or - the at least one elastic return element (300) is embodied as a rope or band, wherein the return element in particular comprises or is a rubber cable, preferably with rubber threads and / or rubber bands and a braided cover.

6. The line guide apparatus according to Claim 5, characterized in that an adjusting device (302; 927) for adjusting the pretensioning of the return element (300) is provided at at least one end region of the variable-length portion (11), in particular at an end link (200; 900) of the variable-length portion.

7. The line guide apparatus according to one of the preceding claims 2 to 6, in particular according to Claim 4, characterized in that a middle piece (250; 800) is provided between two sub-portions (11A, 11B) of the variable-length portion, wherein the middle piece (250; 800) has strain relief (840) for lines (60) to be guided and / or preferably has a greater structural length than the structural length or pitch of the number of links of the variable-length portion (11), and / or wherein the middle piece (250; 800) is connected in particular at each of its longitudinal ends in each case with one of the sub-portions (11A, 11B) rotatable in opposing directions, in particular via respectively opposing rotary guides (730A, 730B).

8. The line guide apparatus according to one of the preceding claims 2 to 7, in particular according to Claims 3 and 5, characterized in that at least the links (200A, 200B; 700A, 700B) of the variable-length portion (11) in each case have a central core (210; 710) with a central passage opening (225; 725) through which the elastic return element (300) is passed; and / or in that the core (210; 710) has guide elements (220, 230; 720, 730) of the rotary guide; and / or the core (210; 710), on longitudinal adjustment of two links relative to one another, predetermines as a function of direction a relative rotation in the one or the opposing direction of rotation about the longitudinal direction.

9. The line guide apparatus according to one of the preceding claims 2 to 8, in particular according to Claim 8, characterized in that at least the links (200A, 200B; 700A, 700B) of the variable-length portion (11) in each case have a central core (210; 710), which forms a joint head (220; 720) and a joint receptacle (230A, 230B; 730A, 730B) opposite in the longitudinal direction, which latter is matchingly configured for articulated connection with the joint head of the next link, wherein joint head and joint receptacle preferably form the rotary guide for predetermining the relative rotation, in particular by one or more helically running guide faces (232) on the inside of the joint receptacle (230A, 230B; 730A, 730B), which interact to predetermine the relative rotation with one or more guide elements on the joint head (220; 720).

10. The line guide apparatus according to Claim 9, characterized in that - the joint head (220; 720) has a basic shape with a substantially triangular cross-section, preferably with arcuately rounded sides (221), whose three vertices (222) are guided as guide elements against corresponding helically running guide faces (232) on the inside of the joint receptacle (230A, 230B; 730A, 730B); or - the joint head (120) has a basic shape with a substantially elliptical cross-section, whose two major vertices are guided as guide elements against corresponding helically running guide faces on the inside of the joint receptacle (130); and / or - joint head and joint receptacle (220, 230; 720, 730) form an articulated connection which is longitudinally adjustable, relatively rotatable and, for three-dimensional mutual deflection of the connected links, swivelable about at least two axes perpendicular to the longitudinal direction, wherein in particular the sides of the basic shape of the joint head are concavely shaped in the longitudinal section, in particular corresponding to a radius of curvature for three-dimensional deflectability.

11. The line guide apparatus according to Claim 9 or 10, characterized in that - the central core (710), at least the joint receptacle, is formed by two separate components (710A, 710B) which are connectable to one another; or - the joint receptacle (1230A, 1230B) is formed by at least two separate insert parts (1250A, 1250B), which are attached to the core in a receptacle, wherein each insert part preferably in each case has a helically running inner surface (232).

12. The line guide apparatus according to one of the preceding claims 2 to 11, characterized in that at least the links (700A, 700B) of the variable-length portion (11) or all links in each case have a central core with at least two substantially radial webs (72) by way of which in each case at least one shell segment is retained, to delimit the accommodation space in the radial direction, wherein the shell segments (71) are preferably arranged in upwardly pivotable manner and / or are of flexible construction and form an insertion opening (71A, 71B) between two shell segments (71); - wherein preferably further provided is that at least in the variable-length portion (11), the shell segments (201; 1201) form a circumferentially and longitudinally closed tube, wherein the connection of respectively successive links comprises a rotary guide (1320, 1330) at the shell segments.

13. The line guide apparatus according to one of the preceding claims 2 to 12, characterized in that the connection longitudinally adjustable in the longitudinal direction in each case comprises at least two longitudinal stops, which restrict the longitudinal adjustment of two links in both directions, wherein the longitudinal stops (733) are formed on the core (710) and / or on shell segments, wherein preferably both longitudinal stops are formed by a joint receptacle (730A, 730B) on the core (710); wherein preferably further provided is that the longitudinal play of the longitudinally adjustable connection amounts to at least 20%, preferably to at least 30% and in particular up to 45% of the link pitch or axial structural length of the link (200A, 200B; 700A, 700B), in particular of the central core.

14. The line guide apparatus according to one of the preceding claims, further comprising at least one line (60) guided in the line guide apparatus (10)), characterized in that the at least one line is arranged to run helicoidally or helically in the variable-length portion, in particular corresponding to a first helix coil (S1; 61A) in the first sub-portion (11A) and a second helix coil (S2; 61B) in the second sub-portion (11B) running with an opposing direction of rotation.

15. A robot (1), in particular an industrial articulated-arm robot, characterized by a line guide apparatus (10) according to one of preceding claims 1 to 14.