Abstract:
A longitudinal guiding device for a conveying device includes at least one guide rail with at least one profile body, and a holding device with a slot-like receiver. The at least one profile body includes a longitudinally running, cross-sectionally concave recess that defines a guide surface for a conveying device. The at least one profile body further includes a longitudinally running, outwardly directed insert strip. The at least one profile body of the at least one guide rail is held on the holding device via the insert strip inserted into the slot-like receiver.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to a conveying chain for a conveying means of a conveying device, comprising a plurality of chain links which are connected to one another, wherein the chain links via joint connections are connected to one another in a manner pivotable in each case about a first axis and a second axis aligned perpendicularly to the first axis, into the conveying chain. The invention moreover relates to a chain link for a conveying chain according to the invention. 
     Description of Related Art 
     Chain conveyors, with which a conveying member, such as grippers or plate elements for example, is led along a revolving track through a conveying device by way of a conveying chain, are generally known. 
     Thus for example, the document EP-A-1 975 093 describes a side bow conveying chain which is formed from inner chain links and outer chain links. The individual chain links are connected to one another via a type of universal joint connection and have two pivot axes which are perpendicular to one another. The outer chain links moreover comprise connection locations, via which carrier plates can be fastened with a positive fit. The guiding of the conveying chain is effected here via sleeve-like projections on the outer chain links which lie on the guide track. This conveying chain has the disadvantage that this is still constructed of a multitude of different components, such as e.g. outer chain links and inner chain links. 
     A modular conveying system with a modularly constructed conveying belt is described in the document U.S. Pat. No. 5,911,305. The conveying belt itself is constructed of individual joints and comprises bending sections to the side, which engage around a guide strip. Although the conveying system is likewise constructed in a modular manner, individual components or links are only suitable for the design of a certain belt conveyor. 
     DE 2118232 describes a conveying device with a conveying chain which is constructed of chain links of the same type. The chain links each comprise a fork-like receiver, into which a coupling piece of an adjacent chain link engages, said adjacent chain link being connected to the fork-like receiver via a round rod designed as a joint pivot. The chain here has exclusively the function of a pulling means. Other functions are not assigned to the conveying chain. The conveying member which here consists of plates is fastened on the round rods which lead laterally away from the chain links. 
     EP-A-1 902 978 also describes a plate conveyor with individual carrier plates which are movably connected to one another. Runner rollers are fastened on the carrier plates. The carrier plates thus themselves form the chain links. 
     BRIEF SUMMARY OF THE INVENTION 
     It is the object of the present invention to then suggest a conveying chain which consists of as little as possible different components, is robust and simple to drive. Moreover, the conveying means should be movable in a reliable manner and with little wear. The connection between the individual chain links should moreover be simple and should be able to be created where possible without any tools. Despite this, the connection should reliably hold in different pivot positions. The conveying chain should moreover be designed in a flexible manner, so that different conveying systems, such as e.g. gripper conveyors or plate conveyors can be realised with the same conveying chain. 
     This object is achieved by the conveying chain according to the independent claim. The dependent claims contain preferred further developments of the invention. 
     The conveying chain according to the invention is characterised in that this, with regard to the shaping is preferably constructed of constructionally identical chain links, and the chain links in each case at a first end section comprise a receiver and at the second end section comprise a coupling body engaging into the receiver of an adjacent chain link. The receiver and the coupling body are now designed such that these can be connected to one another by way of an insertion-rotation movement, for forming the joint connection. Apart from the mentioned end sections, the chain links comprise preferably a middle section in each case between the first and the second end section. The term “adjacent chain link” here means the chain link which runs in front or runs behind, in the conveying chain. 
     The term “constructionally identical with regard to shaping” in particular is relates to end sections as well as middle sections, for connecting a conveying member, and which are formed identically with regard to design. The chain links do not need to be identical with respect to possible connection interfaces for attaching runner rollers, as described further below, but however are preferably likewise identical. 
     In a preferred further development of the invention, the coupling body comprises a joint head, and receiver a joint socket. The joint socket encompasses the joint head preferably beyond its equator in the operating position. Such a connection is also referred to as an enarthrodial joint in medical technology. The joint head is preferably connected to the base body, i.e. the middle section, of the chain link via a neck section. The joint head is usefully rigidly connected to the base body of the chain link. The joint socket comprises an introduction opening for introducing the joint head into the joint socket. The introduction opening for this is preferably directed to the adjacent chain link. The joint head, the joint socket and the introduction opening are now preferably designed such that the joint head, for forming the joint connection via an insertion-rotation movement, is inserted through the introduction opening into the joint socket and by way of a subsequent rotation movement can be secured against sliding out opposite to the insertion direction. The insertion movement is preferably effected in the longitudinal direction of the conveying member or conveying chain. 
     For this, the introduction opening and the joint head are preferably designed such that the joint head and thus the associated chain link can only be introduced into the joint socket of the adjacent chain link, when rotated in a certain angular position or in a certain angular region relative to the joining partner, i.e. the adjacent chain link, about the longitudinal axis of the conveying chain or the chain link. This angular position or angular region is selected or set such that the chain links cannot be decoupled during operation of the conveying chain, i.e., the mentioned angular position or the mentioned angular region corresponds to a twisting or rotation of two chain links coupled to one another, which these would never assume in all pivot positions relative to one another during operation of the conveying chain. This relates to the pivoting of the chain links relative to one another about the first and the second pivot axis A 1 , A 2 . 
     The joint connection can e.g. be designed such that the chain links are rotatable relative to one another by 360° about the longitudinal axis L of the chain link. The joint connection is further preferably designed such that the chain links are pivotable relative to one another only in a limited angular region or range of e.g. 5° to 30° about the second pivot axis A 2 . The pivotability can for example be limited by way of the design of the edge of the receiver or of the joint socket. 
     The coupling body, the receiver and the introduction opening are advantageously designed such that two chain links can only be connected to one another when these are rotated relative to one another about their longitudinal axis (L) by an angle in the range of 45° to 135° and in particular about 90°. This in particular relates to the embodiment of a joint connection with a joint head, a joint socket and a slot-like opening as described above. 
     According to a particularly preferred embodiment of such an insertion-rotation connection, the coupling body comprises a joint head with two flattened sides which lie opposite one another. The flattened sides preferably form two plane surfaces. The surfaces can lie parallel to one another. The joint socket for its part comprises a slot-like introduction opening which is directed to the adjacent chain link, for the insertion of the joint head. The slot-like opening as well as the laterally flattened joint head are thus designed and matched to one another such that the joint head can only be introduced into the joint socket when the two elements are at a certain angle or angular region to one another. The term “angle” here means a rotation angle about a rotation axis which runs in the longitudinal direction of the conveying chain and which is perpendicular to the axis A 1  and A 2 . If the two chain links are equally aligned, then the rotation angle is 0°. The width of the slot-like opening is thus adapted to the width of the joint head between the two flattened sides. In an advantageous design, the slot-like opening corresponds to the (largest) cross section of the joint head which is flattened on two sides, or is somewhat larger. I.e., the slot-like introduction opening and the cross-sectional shape of the joint head are congruent. 
     The slot-like opening and the joint head flattened on two sides are then arranged on the chain link such that the angular positions of the joint socket and of the joint head relative to one another in the operational position lie outside the angle or the angle region which the parts must assume for joining together. The two chain links must be brought into an angular position relative to one another, in which the flattened joint head is aligned to the slot-like opening, for joining these together. 
     The joint head can e.g. have a spherical basic shape with the mentioned flattened sides. The joint socket is usefully designed in an equal and opposite manner to the basic shape of the joint head. The neck section has a smaller diameter than the maximal diameter of the joint head. The diameter of the neck section moreover can correspond to the width of the joint head between the two flattened sides, or be smaller. 
     The conveying chain with regard to the shaping and material can be constructed from constructionally identical chain links. The chain links are preferably designed in a single-part manner. The chain links can be manufactured as single-component or multi-component chain links, i.e. from one or more different materials. A single-component chain link means that the complete component is manufactured from the same material. In contrast, multi-component chain link means that the chain link is constructed from a combination of several, e.g. two different materials, and individual sections or parts of the chain link are manufactured from different materials. A single-component chain link can e.g. be obtained via inserts of material which is different to the base body. Moreover, a multi-component chain link can also be obtained by way of an injection moulding method, in which two or more different plastic materials are processed in different injection moulding steps, into a one-part component. Apart from this, it is also possible for the chain link to be coated with another material over part of the surface or the complete surface. This material for example has friction-reducing characteristics. The material can e.g. be PTFE or contain this. Thus e.g. one can envisage the chain links with regard to shaping and material being constructionally identical and either the coupling body or the receiver being coated with another material. One can also envisage two embodiment types of chain links which are constructional equal with regard to shaping being provided. One embodiment type of chain links thereby has a partial-surface or complete-surface coating with another material. The other embodiment type of chain links preferably has no coating. In this case, the coupling body as well as the receiver would be coated. The coating can be envisaged as a separate method step subsequent to an injection moulding method. The coating can also be a method step during the injection moulding method. 
     The individual, different materials of such a component could have characteristics which meet different functional tasks which individual regions of a component must fulfill. 
     The material or a material, from which parts of the chain link or the complete chain link can be manufactured, is preferably a plastic or a reinforced plastic. The material or a material can however also be metal, e.g. an iron metal such as steel or aluminium. If the chain link is manufactured from plastic, then this can be manufactured e.g. by way of injection moulding. If the chain link is manufactured of metal, then this can be manufactured by way of a casting method. The chain links are then corresponding metal cast parts. 
     It is possible for the chain link to be manufactured from plastic, and to comprise inserts such as guide sleeves, pins, receivers (joint socket), coupling bodies (joint head), ball bearings, complete runner rollers, rolling bodies, pivot bodies, etc., which are already integrated into the base body, of e.g. plastic, in the manufacturing method. The inserts thereby consist of a material which is different than the base body, e.g. metal. An injection moulding method is particularly suitable for manufacturing chain links with inserts, e.g., inserts can be provided, which, orientated in the longitudinal direction L, are embedded into the chain link and are designed in order to accommodate tensile forces. 
     A further object of the invention is also to keep the friction between the receiver and the coupling body as small as possible, in order to thus prevent excess wear. Different ideas are possible for solving this problem. 
     According to a first solution of this task, the chain link is a multi-component chain link manufactured from several, preferably two different plastic materials. Despite this, the chain link is preferably produced in a single-part manner. At least the joint head and the joint socket are manufactured from two different plastic materials. The two plastic materials are usefully selected such that the friction coefficient between the joint head and the joint socket and accordingly also the wear is as low as possible. The multi-component chain links, such as e.g. two-component chain links, of several, e.g. two different plastic materials can be manufactured in a multistage injection moulding method. In this case, the chain links are preferably designed constructionally identically with regard to shaping and material. 
     According to a particularly preferred embodiment of a multi-component chain link, in particular a two-component chain link, the one plastic material comprises a friction-reducing component, preferably PTFE (polytetrafluorethylene), in particular PTFE in a quantity of greater than 0% and smaller than 20% (volume percent). Thereby, either the coupling body, i.e. the joint head, or the receiver, i.e. the joint socket, is manufactured from this plastic material. The plastic material of the counter-element in contrast preferably has no friction-reducing additions. The base material of the chain link can e.g. be POM (polyoxymethylene). 
     According to a second solution of the task mentioned above, the individual chain links of the conveying chain although being designed in a constructionally identical manner with regard to the shaping, this however is not the case with regard to the material. Thus the conveying chain with regard to the material of the chain links can be manufactured of a plurality of different embodiment types of chain links. Chain links of different embodiment types are preferably arranged in the conveying chain in an alternating manner. The individual chain links here however preferably consist of a single material. 
     According to a particularly preferred embodiment, the conveying chain comprises two embodiment types of chain links which with regard to the material are not constructionally identical. Chain links of these two embodiment types are in each case arranged in an alternating manner in the conveying chain. The materials of the embodiments of chain links which are not constructionally identical are preferably selected such that the joint head and the joint socket of a joint connection each have a low friction. This means that in the manner mentioned above, on the one hand the friction coefficient between the two components can be lowered, and on the other hand the wear on the contact surfaces can be minimised. 
     Thus e.g. the material of the first embodiment type of a chain link can be a plastic with a friction-reducing component, preferably PTFE, in particular PTFE in a quantity of larger than 0% and smaller than 20% (percentage by volume). The material of the second embodiment of a chain link is a plastic without PTFE. The (base) material of the first and second embodiment type can e.g. be POM or contain this. 
     If a conveying chain consists of several embodiment types of chain links, then the chain links of one embodiment type in each case have a specific colouring which differs from the colouring of the chain links of other embodiment types. In this manner, the chain links of different embodiment types can be optically simply differentiated from one another. 
     The chain links, independently of whether these are single-component or multi-component chain links, can preferably be manufactured by way of an injection moulding method in one or more injection moulding steps. 
     In a further development of the invention, the middle section of the chain link comprises first connection means for the non-positive and/or positive connection of the chain links to a conveying member or its conveying elements. The conveying chain with the conveying member forms a conveying means. The first connection means are preferably provided on a connection side of the chain link which is directed to the conveyed products. The first connection means can comprise plug-in (insertion) openings or detent hooks, wherein the conveying member comprises the accordingly complementary, second connection means. The connection between the conveying element and the chain links is effected e.g. via a plug-in connection, in which detent hooks hook into plug-in openings and lock (snap) therein. The detent hooks are e.g. designed in a spring-elastic manner and on inserting are bent laterally away from one another or to one another amid the application of force, so that they wedge into the plug-in receiver on locking or snapping in. The detent hooks can be designed in a tab-like manner. The detent hooks amid a force action must be laterally bent away again, so that the locking lugs can release from the detent (locking) position, for releasing the connection. Only then can the conveying element be released from the chain link. Through-openings, e.g. two tool openings can be provided in the region of the detent hooks, so that the release or removal of the conveying element from the chain link is also possible from the conveying surface and therefore also in the operationally ready condition of the conveying device. A tool, e.g. a pliers-like tool with clamping or spreading limbs can then be introduced through the tool openings, by way of which tool the detent hooks can then be bent away laterally and thus the hooking can be released. In this case, the detent hooks are preferably attached on the conveying element. 
     The conveying member can consist of plate-like elements which can be fastened on the chain links in the described manner. The conveying member can however also comprise grippers suitably fastened on the chain links. 
     The chain link in a further development of the invention can comprise a drive interface for the asymmetrical or symmetrical introduction of a drive force. The drive interface in particular is a toothing on the chain link for the purpose of forming an engagement with the toothing of a drive means. A drive interface for the asymmetrical introduction of a drive force means that the drive force is only introduced onto the chain link from one side. Accordingly, the chain link has corresponding interface means such as e.g. a toothing, only on one side, e.g. on the opposite side lying opposite the connection side to the conveying member. A drive interface for the symmetrical introduction of a drive force means that the drive force is introduced onto the chain link from two opposite sides. Accordingly, the chain link comprises interface means, e.g. a toothing, on two oppositely lying sides, e.g. in each case laterally and below the connection side to the conveying member or to runner rollers on the conveying means. The symmetrical force introduction has the advantage that with this, no counter force needs to be exerted onto the chain link, as this is the case with an asymmetrical force introduction for the purpose of preventing a yielding movement of the conveying chain. 
     The toothing is preferably designed in a plane. It extends in each case preferably over a surface section. The toothing can be designed in a serrated manner and comprise teeth, staves or ribs running transversely to the conveying direction or longitudinal direction. The toothing serves for the positive-fit connections to a drive means for the force transmission and movement transmission. The drive means and the drive interface can be designed for accelerating as well as for braking the conveying means. The features of the drive interface here are to be understood as independent features. 
     In each case, at least one runner roller can be attached on individual or all chain links. The at least one runner roller can already be attached with the single-part manufacture of the chain link, or be attached at a later stage via suitable connection interfaces such as a pivot bodies, onto the chain link which is preferably manufactured as one piece. The runner roller or runner rollers on the chain links serves for supporting the conveying means on a longitudinal guiding device and for the guided movement of the conveying means along a conveying track defined by a longitudinal guiding device. Preferably, in each case a runner roller is attached on both sides of a chain link, or a connection interface is provided for this. I.e. two runner rollers are arranged, e.g. symmetrically to one another, per chain link. 
     In a preferred further formation of the invention, in each case a runner roller is arranged on both sides of the chain link and is fastened on this. The runner rollers each form a support (contact) location to a guide rail of a longitudinal guiding device. The support locations can be support points or support lines or support surfaces. The support locations of the two runner rollers together with the joint connection lie on a common straight line. The support locations of the two runner rollers in particular together with the geometric centre of the joint connection lie on a straight line, or with the first pivot axis A 1  of the joint connection lie on a common straight line. The geometric centre of the joint connection is e.g. formed by the intersection point of the first and second pivot axis A 1  and A 2 . 
     The chain links can be designed in a lightweight construction manner, in particular in a hollow construction manner, with crossing chamber walls which enclose open and/or closed chambers. The chain links in particular can be manufactured in a lattice construction manner. 
     The joint connection between the individual chain links is moreover preferably designed such that the chain links via contact surfaces can transfer or transmit push pulses or compressive/push forces onto adjacent chain links. Preferably, the chain links or the joint connections are designed such that these can mutually transmit tensile forces as well as push pulses or compressive forces. By way of this, the conveying chain can be driven by way of tension forces as well as compression forces. This means that the conveying chain can be pulled as well as pushed. The conveying chain is secured with respect to compressive forces as well as tensile forces thanks to the joint connection according to the invention. 
     The invention moreover also relates to a chain link for a conveying chain. The chain link is characterised in that this in each case on a first end section comprises a receiver and on a second end section comprises a coupling body, wherein the coupling body is designed such that this can be introduced into the receiver of an adjacent chain link which is constructionally identical with regard to shaping. Moreover, the chain link is designed such that the receiver can assume a joint connection with the coupling body of the chain link which is adjacent in the longitudinal direction of the conveying chain, and the coupling body can assume a joint connection with the receiver of the other chain link which is adjacent in the longitudinal direction of the conveying chain, by way of an insertion-rotation movement. 
     The structural and functional features with respect to the chain links and which are described in this description in the context of the conveying chain, of course also apply to the independently claimed individual chain link, which is why these features or no longer described separately at this location. 
     The present invention is characterised by an economical manufacture of the individual components. A one-part, single-component or multi-component chain link or conveying element can be manufactured e.g. in a few method steps and with a lower effort with regard to manufacturing technology and logistics. The constructionally identical chain links as well as the preferably likewise constructionally identical conveying elements, with or without inserts can be manufactured in one working step by way of a single-stage or multi-stage injection moulding method. Moreover, pivot bodies, arms, roller element cages and/or complete runner rollers can also be integrally manufactured with the chain link or conveying element in this manufacturing step. Moreover, the complete rolling bodies can be integrally connected as an insert, to the chain link or the conveying element with the manufacture of this. 
     A further, independent invention relates to a longitudinal guiding device, in particular for a conveying device. The subsequently described longitudinal guiding device however also in combination with the conveying chain described above or with the conveying means described above and in their various designs can form particular embodiments of conveying devices. 
     The mentioned longitudinal guiding device typically comprises a guide rail as well as a holding device, on which the at least one guide rail is held or mounted by way of fastening means. The fastening means can be designed for the releasable or non-releasable fastening of the guide rail on the holding device. The fastening can be with a material fit (e.g. weld connection) or with a non-positive and/or positive fit. 
     The guide rails or their subsequently described profile bodies are however preferably repeatedly releasable from the longitudinal guiding device and repeatedly fixable thereon. In this case, the fastening means are preferably designed for a non-positive and/or positive fixation of the profile bodies on the holding device. The fastening means can e.g. be holding elements in the form of holding clips, holding tabs, holding strips, holding bars, holding slides or holding screws. The holding elements can e.g. be welded or attached in another manner, onto the holding device or onto the transverse connection elements, at a suitable location. 
     The longitudinal guiding device in then characterised in that the at least one guide rail is formed from at least one profile body which comprises a longitudinally running, cross-sectionally concave recess designed as a guide surface for a conveying means. The concave recess in particular is characterised by a completely or partly arched cross-sectional course. The mentioned recess thereby forms a guide channel for the conveying means or their runner rollers. 
     The guide surface in particular is designed for guiding runner rollers of a conveying means. The runner rollers can thereby lie on the guide surface which in this case corresponds to a running surface, in a surfaced or linear manner. The type of support (contact) of the guide rollers on the running surface (surfaced or linear) depends on the cross-sectional geometry of the runner rollers and the longitudinally running, concave recess. 
     The runner rollers can e.g. comprise a running surface of plastic. The rolling surface of the runner rollers can have a concave cross-sectional geometry 
     The longitudinal guiding device or its guide rail are designed as a support for the conveying means or their runner rollers, wherein the support force is produced by the gravity force and/or centrifugal forces, acting on the conveying means. 
     According to a first embodiment of the invention, the profile body consists of an extrusion profile or continuous casting profile, wherein the at least one longitudinally running, cross-sectionally concave recess is incorporated into the profile cross section of the profile body with the extrusion or continuous casting method. 
     According to a second embodiment, the profile body is a formed (reshaped) profile which is manufactured from a tubular starting profile which is plastically formed in its cross section. The plastic forming is effected e.g. via a mechanical forming (reshaping) method. The tubular starting profile is e.g. designed in a thin-walled manner. 
     The solution according to the second embodiment permits the use of conventional tube profiles which are available on the market, such as round tubes, or rectangular tubes, at accordingly favourable conditions. The starting profile does not need to be manufactured separately, and the procurement of expensive tools and installations for manufacturing the starting profile can be done away with. The profile bodies formed from round tubes and with these, the guide rails, can be produced in an extremely inexpensive manner by way of this. 
     The guide rails can be designed as disposable components which when worn due to abrasion can be exchanged in an inexpensive manner and without any problem, on account of the inexpensive and simple manufacture of these guide rails. With the pairing of the guide rails/runner rollers, one can envisage the guide rails being designed such that these have a greater wear than the runner rollers, e.g. due to a lower hardness, in order thus to conserve the runner rollers, for reducing the wear of these. 
     According to a further development of the profile body of both embodiments, the profile body comprises at least two longitudinally running concave recesses which are arranged on its outer periphery and are each designed as guide surfaces. The profile body in particular can form two, three or four longitudinally running, concave recesses of the same or different cross-sectional geometry, which are designed as a guide surface for the conveying means. 
     The at least two longitudinally running, concave recesses preferably run parallel to one another. The at least two longitudinally running recesses are each preferably designed as guide surfaces, so that one of the longitudinally running recesses assumes the function as a guide surface in the longitudinal guiding device, in dependence on the assembly of the profile body on the holding device. 
     One can now envisage the at least two longitudinally running recesses having the same cross-sectional geometry and thus being able to be applied selectively in the conveying device as guide surfaces. As explained in more detail further below, this permits the exchange to a different guide surface if one of the guide surfaces, e.g. on account of wear, can no longer be used for guiding the conveying means. 
     However, one can also envisage the at least two longitudinally running recesses being designed in a different manner, i.e. having different cross-sectional geometries. This permits the application of the profile body in the longitudinal guiding device with guide rails with differently dimensioned guide surfaces. Specifically, differently designed guide surfaces for the runner rollers are necessary, depending on the conveying means or runner rollers which are applied in the conveying device. 
     The at least two longitudinally running, concave recesses are preferably arranged such that the profile body has a point-symmetrical cross-sectional shape. 
     If now a profile body or a guide rail formed from the profile bodies has several longitudinally running concave recesses which are designed as guide surfaces, then the profile bodies are fastened in the holding device in a manner such that one of the longitudinally running, concave recesses lies in the correct position for assuming its function as a guide surface. If the running surface of a profile body of a guide rail is worn above a fixed tolerance value, then another longitudinally running, concave recess of the same profile body can be used as a running surface. For example, by way of rotating the profile body about its longitudinal axis, a longitudinally running recesses lying on the outer periphery of the same profile body can serve as a running surface. The life duration of the guide rail or its profile body can be multiplied by way of the use of different longitudinally running, concave recesses of the profile body as a running surface. 
     In a further development of the profile body, according to the second embodiment, the at least one, longitudinally running, cross-sectionally concave recess in the formed profile is incorporated into the starting profile with a plastic forming method. 
     According to a further development of the profile body of both embodiments, the profile body amid the formation of an X-shaped cross-sectional shape comprises four longitudinally running, cross-sectionally concave recesses which are arranged or incorporated uniformly on its outer periphery. If the profile body is a formed profile according to the second embodiment, then the four longitudinally running recesses are shaped into a tubular starting profile by way of a plastic forming method. 
     According to a further development of the profile body of both embodiments, the profile body at least on its end sections forms a hollow chamber which is open at the face side and is preferably continuous in the profile longitudinal direction. In a particular development, the profile body is an in particular closed hollow profile. Closed hollow profiles are characterised by a high torsional stiffness with a simultaneously low weight. If the profile body is a hollow profile, then the concave recesses in the profile interior preferably form a cross-sectionally convey chamber wall which, as described hereinafter, serves e.g. as a centring surface for forming a surface contact or line contact with a centring means. 
     According to a further development of the profile body according to the second embodiment, the formed profile with its at least one longitudinally recess on the outer periphery is shaped from a round tube with a circular or oval cross section. The starting profile can also have a polygonal cross-sectional shape and e.g. have a square or rectangular cross section. 
     The profile body according to both embodiments can consist of metal such as steel (stainless steel) or aluminium, or of plastic. 
     The starting profile for manufacturing the formed profile according to the second embodiment can likewise be an extrusion profile or continuous casting profile. Starting profiles in the form of tube profiles, in particular of round tubes, can however e.g. also be manufactured of a rolled produce (e.g. sheet-metal) by way of a forming or bending method and subsequent welding method. 
     According to a further development of the profile body of both embodiments, the profile body comprises at least two longitudinally running, concave recesses which are adjacent one another and arranged on the outer periphery of this profile body, wherein the concave recesses enclose or form a longitudinally running, roughly radially outwardly directed insert strip, also called insert beading, for the insertion into a slot-like recess of a holding device. If the profile body is a formed profile of a hollow profile, then the insert strip can be designed in a double-walled manner by way of leading together two profile walls. 
     If the profile body comprises several longitudinally running recesses which are designed as guide surfaces, then preferably a corresponding number of insert strips is provided, which are designed and arranged in the profile body such that the one or the other longitudinally running recess assumes the position as the guide surface in the longitudinal guiding device, depending on which insert strip is inserted into the slot-like recess of the holding device. 
     If the profile body as described above comprises four longitudinally running, concave recesses amid the formation of an X-shaped cross-sectional shape, then the X-shape is formed by the insert strips between the longitudinally running concave recesses, said insert strips being directed roughly radially outwards on the outer periphery. 
     According to a further development of the longitudinal guiding device, the at least one guide rail is formed from a plurality of profile bodies which are arranged one after the other and end-to-end. The profile bodies can be designed in a straight manner for straight conveying sections and in a curved manner for curved conveying sections. The curvature is e.g. achieved by way of a bending method. Hereby, in particular, the straight profile bodies comprise two or more longitudinally running, concave recesses. Since the mentioned recesses as the case may be increase the bending stiffness, such profile bodies are not always particularly well suitable for the manufacture of bent profile bodies. For this reason, the bent profile bodies preferably in each case have only one such longitudinally running recess. 
     Two profile bodies forming an end-to-end joining can be aligned to one another without any offset by way of a centring means which is introduced into hollow chambers open at the face side, of the profile bodies, in a manner engaging over the profile and which is fixed radially in the hollow chambers. I.e. the transitions between two profile bodies are smooth and form no shoulders or channels. 
     The centring means can e.g. be a centring pin or a centring tube. The hollow chambers can e.g. form centring surfaces, on which the centring means bears and via which this is radially fixed. The centring surfaces are e.g. chamber walls or profile walls. The centring means can bear on the centring surfaces in a surfaced manner amid the formation of a surface contact, or in a linear manner amid the formation of a line contact. The profile bodies are thus stuck together in the longitudinal direction via the centring means and are thus automatically centred by the centring means. 
     The holding device of the longitudinal guiding device, according to a particular further development of the invention comprise slot-like receivers, via which the profile bodies of the guide rails are held. In particular, an insert strip of the profile body is inserted into the slot-like receiver, e.g. with a positive fit. 
     According to a further development of the longitudinal guiding device, this comprises two guide rails which are distanced to one another, led in a parallel manner, held via the holding device and preferably connected to one another. 
     If the longitudinal guiding device comprises two guide rails which are led next to one another, then the holding device comprises at least one transverse connection element with slot-like receivers, via which the profile body of the two guide rails are held. The transverse connection element as a result connects the guide rails to one another. 
     The longitudinal guiding device according to the invention further also relates to a method for manufacturing a profile body of a guide rail of a longitudinal guiding device described above. The method comprises the following steps: providing a premanufactured hollow profile, in particular tube profile; and incorporating a longitudinally running, cross-sectionally concave recess into the outer periphery of the hollow profile by way of plastic forming. 
     In a further development of the method according to the invention, this comprises the following step: incorporating two adjacent, longitudinally running, cross-sectionally concave recesses into the outer periphery of the hollow profile and creating a longitudinally running insert strip between the recesses by way of plastic forming. 
     Of course, method features can be combined with device features and vice versa. The mentioned longitudinal guiding device is particularly applied in a conveying device. 
     The described conveying means and longitudinal guiding device permit a three-dimensional design of the conveying path. Thus e.g. spiral-shaped conveying paths with simultaneous curves to the left or right and positive or negative gradients can be envisaged. The conveying device with conveying means and longitudinal guiding device is lightweight, but despite this is stable as well as low-wearing. 
     Less drive power is necessary due to the fact that the conveying means and in particular the conveying chain is relatively light and moreover low in friction. The drives can therefore be accordingly dimensioned in a smaller manner on account of this. Several comparatively small drives can thus be arranged distributed over the conveying device and locally drive the conveying means. 
     The conveying device with a conveying chain according to the invention can also be applied in foodstuff processing, since it is simple to clean. The cleaning agent e.g. can run away in an unhindered manner thanks to the design according to the invention. Moreover, the conveying device according to the invention permits a simple and rapid assembly. Existing conveying devices can be retrofitted in a simple and inexpensive manner with the conveying device according to the invention, or can be replaced by this. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The subject matter of the invention is hereinafter explained in more detail by way of preferred embodiment examples which are represented in the accompanying drawings. In each case are shown schematically. 
         FIG. 1  is a perspective view of a first embodiment of a conveying means with a conveying chain according to the invention; 
         FIG. 2  is an exploded perspective view of the conveying means of the conveying device according to  FIG. 1 ; 
         FIG. 3  is a perspective view of a conveying device with a conveying means according to  FIGS. 1 and 2 ; 
         FIGS. 4 a -4 b    are perspective views of a further conveying means with a first conveying chain according to the invention; 
         FIGS. 5 a -5 b    are perspective views of a further embodiment of a chain link according to the invention, with runner rollers; 
         FIGS. 6 a -6 b    are perspective views of a further embodiment of a conveying device with a conveying means; and 
         FIG. 6 c    is a perspective view of a further embodiment of a longitudinal guiding device. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1, 2 and 3  show a conveying means  1  with chain links  2  which can be led together via an insertion-rotation connection, into a conveying chain. The conveying means further comprises a conveying member  20  with conveying elements  21  in the form of constructionally identical, plate-like carrier elements which are arranged one after the other into a conveying member  20 . The plate-like carrier elements  21  form a conveying surface  23 , on which the conveyed products are conveyed (not shown). Two connection means in the form of projecting detent hooks  24 , via which the carrier elements  21  can be fastened via first connection means  9  onto the chain links  2 , are attached on the lower side of the carrier elements  21  which is opposite to the conveying surface  23 . The carrier elements  21  at their sides which face the preceding and subsequent conveying element  21  each comprise a plurality of prong-like, slightly bent projections  22  which are distanced to one another. These projections  22  are envisaged for a meshing engagement, in particular in curve regions, into likewise slightly bent, prong-like projections  22  of the adjacent, similarly designed carrier element  21 . 
     The chain link  2  comprises a first end section  13 , a second end section  14  and a middle section  12 . The second end section  14  comprises a coupling body in the form of a joint head  3  which is connected to the base body of the chain link  2  via a neck section  11 . The joint head  3  has a spherical basic shape. This basic shape is superimposed by two flatted sides  7  on the joint head, which lie opposite one another. The first end section  13  has a spherical receiver in the form of a joint socket  5 . The joint socket  5  forms a ball-shell-like cut-out or recess. The spherical receiver moreover comprises an introduction opening  4  which is directed in the longitudinal direction to the adjacent chain link  2  and through which the joint head  3  can be introduced. 
     The joint head  3  of a chain link  2 , as part of a conveying chain now in each case engages into the joint socket  5  of the adjacent chain link  2 , wherein the joint socket  5  encompasses the joint head  3  beyond its equator, so that the joint head  3  cannot slide out of the joint socket  5  in the longitudinal direction opposite to the introduction direction, in the operating position. 
     The joint socket  5  comprises a slot-like introduction opening  4  for introducing the joint head  3  into this the joint socket  5 . The introduction opening  4  corresponds to the (greatest) cross section of the joint head  3  flatted on both sides, or is somewhat larger. The slot-like introduction opening  4  as well as the laterally flatted joint head  3  are then designed relative to one another and are aligned to one another, such that the joint head  3  can only be introduced into the joint socket  5  when the two associated chain links  2  are rotated by an angle of about 90° relative to one another. The joint head  3  and the introduction opening  4  are equally directed in this introduction position. During operation of the conveying chain, the joint head  3  and the introduction opening  4  in contrast are never equally directed, but are always rotated or twisted at an angle to one another. In the non-rotated position of the chain links  2  relative to one another, the slot-like introduction opening  4  is therefore always perpendicular to the flattened sides of the joint head  3 . For this reason, one of the chain links  2  must always be firstly rotated by an angle of 90° relative to the joining partner  2 , when joining and releasing in the longitudinal direction L of the conveying chain. 
     The middle section  12  of the chain links  2  is designed in a box-like manner with two lateral hollow chambers  9  which serve as first connection means in the form of plug-in receivers. The already mentioned, spring-elastic detent hooks  24  are introduced into the hollow chambers  9  until they lock or detent on the chamber wall in a clamping manner with their detent lug  25  at the exit side, for creating a plug-in connection. The locking or detent hooks  24  with their locking or detent lugs  25  must be accordingly released from the detent position, for releasing the locking or detent connection. 
     The chain links  2  are each designed in a similar manner and apart from the already described joint connection comprise two runner rollers  10  which are each fastened laterally on this in a symmetrical arrangement. The runner roller  10  in each case comprises a rolling body  30  which is mounted via a ball bearing  33  on an axle body  32  and has a rolling surface  31 . The axle body  32  is preferably integrally formed on the chain link  2 , wherein the rolling body  30  is stuck onto an axle stub of the axle body  32  via the ball bearing  33 . The axle body  32  is an angled component part which leads laterally outwards from the chain link  2  and with a connecting axle stub is directed obliquely upwards to the conveying member  20 . The axle body  32  is designed such that the rotation axis R of the runner roller  10  encloses an acute angle α of less than 45° and greater than 10°, preferably from 20° to 40°, in particular from 25° to 35°, with the first pivot axis A 1 . The two rotation axes R of the rolling body pairing run to one another towards the chain link  2  and run apart towards the conveying member  20 . 
     The runner rollers  10  each form support or contact points  34  to the guide rail  41 . The support points  34  of the two runner rollers  10  together with the first pivot axis A 1  of the joint connection lie on a common straight line V. 
     The chain link  2  moreover on the opposite side of the connection side directed to the conveying member  20  comprise a plane and surfaced toothing  8 , which can be brought into engagement with the toothing of a drive means (not shown). 
       FIG. 3  shows a conveying device  19  which additionally to the conveying means  1  comprises a longitudinal guiding device  40  with two guide rails  41  which run parallel and at a distance to one another and are connected to one another via transverse connection elements  44 . The transverse connection elements  44  serve for holding together the two guide rails  41  and as a spacer, in particular for ensuring a constant distance between the two guide rails  41 . The transverse connection elements  44  are designed in a C-shaped manner and at the two ends comprise a bend section  43  which is directed to the respective guide rail  41 . The end sections of the bend sections  43  run parallel to oppositely lying end sections of the guide rails  41 . A surfaced connection zone  42  is formed in this manner, via which the transverse connection elements  44  are connected to the guide rail  41  via a material-fit connection (e.g. bonding, welding, soldering). The transverse connection elements  44  can consist of a bent rolled product. The transverse connection elements  44  can in particular be formed from sectioned, milled or punched strips of a rolled product. The rail profiles  41  in each case comprise concave running surfaces  45  which are arched in cross section and are in the form of a guide channel which are open to the runner rollers  10 , i.e. which are open to one another. The rolling body  30  runs with its rolling surface  31  on the running surface  45 . The rail profile  41  can be an extrusion profile of a steel or aluminium material. Moreover, the rail profile  41  can also be a bent or rolled product of metal, in particular or a steel or aluminium material. Moreover, the rail profile  41  can also be of a plastic or a reinforced plastic and/or of a coated plastic. 
     The conveying means  101  according to  FIGS. 4 a  and 4 b    likewise comprises a conveying chain of a plurality of chain links  102 . The chain links  102  with regard to the essential features are constructed in the same manner as the chain links  2  according to  FIGS. 1 to 3 . Here too, the chain link  102  on a first end section comprises a receiver into the form of a joint socket  5 , as well a joint head  3  on a second end section. The joint socket  5  moreover also here comprises a slot-like introduction opening  4 . The insertion-rotation connection is effected in the same manner as in the embodiment example according to  FIGS. 1 to 3  and is therefore not described in more detail at this location. Moreover, the chain link  102  likewise comprises a toothing  8  of the already described type. The runner rollers  10  are formed via axle bodies  132  on the chain link  102  in the same way and manner as according to the  FIGS. 1 to 3 . The plug-in receivers on the connection side directed to the conveying member  120 , on the middle section of the chain link  102  are slightly modified in their design. Here too however, two lateral chambers  109  are formed, through which detent hooks  124  are led and with their detent lugs  125  hook with the chamber wall at the exit side. 
     The plate-like carrier elements  121  of the conveying member  120  are likewise slightly modified with respect to the embodiment example according to  FIGS. 1 to 3 . The plate-like carrier elements  121  on both sides which in each case face the preceding and subsequent adjacent carrier elements  121  each have a plurality of prong-like projections  122  which are distanced to one another and slightly bent, for a meshing engagement into likewise, slightly bent, prong-like projections  122  of the adjacent carrier element  121 . The prong-like projections  122  however in each case on one side of the carrier element  121  are supported by a guide base  127 , so that the prong-like projections  122  of the adjacent conveying element  121  which engage in a meshing manner and are not supported by a guide base, are optimally led. 
     The carrier element  121  analogously to the embodiment example according to  FIGS. 1 to 3  comprises two detent hooks  124  which each have a detent lug  125  and are arranged distanced to one another transversely to the longitudinal direction. The connection of the carrier element  121  and chain link  102  is effected in the same manner as  FIGS. 1 to 3 . Moreover, in each case two tool openings  126  are provided in the region of the detent hooks  124 , on the carrier element  121 . A tool, e.g. a pliers-like tool with clamping or spreading limbs can then be introduced through the tool openings  126 , by way of which tool the two detent hooks  124  can be laterally bent away and thus the hooking can be released. 
       FIGS. 5 a  and 5 b    show a further embodiment of a chain link  202  with a joint connection according to the invention, wherein the chain link  202  of this embodiment differs only by way of the design of the runner rollers  210  and their connection onto the chain link  202 . For this reason, the corresponding features between the two mentioned embodiments of chain links  2 ,  202  and their functionalities are hereinafter no longer described in detail. Instead, the respective designs with regard to the  FIGS. 1 to 3  are referred to. 
     The chain link  202  likewise comprises two runner rollers  210  which are arranged on both sides of this. The joint socket  205  as part of a first end section  213 , and the joint head  203  with flattened sides  207  as part of a second end section  214  are likewise connected to one another via a middle section  212 . The joint socket  205  here is also designed such that this encompasses the joint head  203  of the adjacent chain link  202  beyond its equator  206 . The middle section  212  in the known manner is designed in a box-like manner with two lateral hollow chambers  209  which serve as plug-in or insertion receivers. The plug-in connection is effected as already described in  FIGS. 1 to 3 , which is referred to with respect to this. The chain link  202  likewise comprises a toothing  208  which likewise extends from the first end section  213  with the joint socket  205  beyond the middle section  212  up to the second end section  214  with the joint head  203 . 
     The runner roller  210  according to the present embodiment comprises a rolling body  230  which comprises three ball elements  234  which are arranged in recesses  235  of a roller element cage  233 . The ball elements  234  are mutually supported in the roller element cage  233  and to the outside form a support or contact point for the rolling guidance and support of the rolling body  230 . The contact point to the guide rail (not shown) in each case lies in the region of a ball segment of the ball element  234  which projects out of the roller element cage  233 . The roller element cage  233  comprises suitable recesses  235  for receiving and rotatably holding the ball elements  234 , wherein the recesses  235  or their openings are designed such that the ball elements  234  cannot fall out of the roller element cage  233 . The ball elements  234  in the roller element cage  233  are arranged in a plane spanned by the two pivot axes A 1  and A 2  in the non-pivoted position of the chain links  202 , wherein two adjacent ball elements  234  in each case enclose an angle of 120°. 
     The rolling bodies  230  are attached laterally on the chain link  202  via a rigid axle arm  232 , also called connection arm. The axle arms  232  here are designed parallel to the first pivot axis A 1 . They could however also be aligned differently. The roller element cage  233  can however be stuck onto the chain link  202  via the axle arm  232 . However, it is also possible for the roller element cage  233  to be designed in a single-part manner together with the chain link  202  and the axle arm  232 . This is independent of the specific design of the rolling body  230  and of the chain link. The rolling bodies  230  here are pressed through openings into the recesses  235  of the roller element cage  233 , for creating the rolling body  230 . 
       FIGS. 6 a  and 6 b    show a further embodiment of a conveying device  300  comprising a conveying means  301  which is composed of a conveying member  320  and a conveying chain, as well as a longitudinal guiding device  340 , via which the conveying means  301  is led along a conveying path. The conveying member  320  is designed analogously to the conveying member  120  according to  FIG. 4 a    and is therefore not described in all details at this location. The conveying member  320  is likewise composed of individual conveying elements  321  which engage into one another in a meshing manner via prong-like projections  322 . The engaging, prong-like projections  322  of the adjacent conveying element  321  on the one side of the conveying element  321  are led by a guide base  327 . The conveying elements  321  are connected to the chain links  302  via detent hooks  312  in the already described way and manner. 
     The conveying chain is composed of chain links  302  according to the invention. The chain links  302  correspond essentially and, with respect to the joint connection, completely to the chain link  102  according to  FIG. 4 b   . The single difference lies in the fact that the present chain links  302  additionally to a toothing  308  attached on the opposing side, in each case comprise a lateral toothing  309  which on both sides of the chain link  302  is arranged directed to the guide rails  341  of the longitudinal guiding device  340 . This lateral toothing  309  has the advantage that the conveying chain can be driven from both sides via the toothing  309 . The drive hereby with a drive toothing engaging at both sides not only produces a pressing force onto the lateral toothing  309  of the conveying member, but simultaneously also the necessary counter-force on the oppositely lying side which prevents the conveying means  301  from escaping the pressing force. 
     The chain link  302  moreover likewise has an insertion-rotation connection with a joint head  303  with flattened sides  3097  which engages into a joint socket on the adjacent chain link (not shown). The joint head  303  is connected to the base body of the chain link  302  via a neck section  304 . In an analogous manner to  FIG. 3 , the chain link  302  moreover comprises runner rollers  310  which are rotatably fastened laterally on the chain link  302  via angled axle arms  311 . 
     The longitudinal guiding device  340  is likewise formed from two guide rails  341  which are led parallel next to one another and are connected to one another via transverse connection elements  344 . The transverse connection elements  344  here are designed in a U-shaped manner and have a U-shaped cross-sectional shape which contributes to the stiffness and bending strength. The transverse connection elements  344  at their free end sections each have a slot-like recess  346 , into which an insert strip  347  of the guide rail  341  is inserted and is fixed via a weld connection  348 . The longitudinal guiding device  340  can be fastened on holders (not shown) via fastening openings  349  on the transverse connection elements  344 . The guide rail  341  has a running surface  345 , along which the runner roller  310  rolls. The running surface  345  is designed in the form of a concave guide channel which is arched in its cross section. 
       FIG. 6 c    shows a further embodiment of a longitudinal guiding device  340 . The longitudinal guiding device  340  in  FIG. 6 c    has the same transverse connection elements  344  as the longitudinal guiding device  340  in  FIG. 6 b   . In contrast to the guide rails  341  in  FIG. 6 b   , formed guide rails  350  are connected via the transverse connection elements  344  in  FIG. 6 c   . The formed guide rails  350  each consist of an initially rotationally symmetrical metal tube with a round cross section and a wall thickness for example of 0.5 mm to 5 mm, whose cross section was formed (reshaped), in a mechanical and plastic manner. 
     The formed guide rails  350  have a point-symmetrical and X-shaped cross section with four identically shaped outer side regions of the cross section. Each of the four outer side regions has a section which can be used as a running surface  351 . This section or this running surface  351  is designed in the form of a concave guide channel which is arched in cross section. 
     Insert strips  352  which are inserted into the slot-like recesses  346  of the transverse connection elements  344  and are fixed for example with a non-positive and/or positive fit by fastening means  353  in the form of holding tabs are formed between the running surfaces  351  of the formed guide rails  350 . The holding tabs  353  can be released and fixed in a repeated manner and permit a simple removal and a simple insertion of the insert strip  352  into the slot-like recesses  346 . The formed guide rails  350  can be fastened on the transverse connection elements  344  in a rapid and simple manner and be separated from the transverse connection elements  344  in a rapid and simple manner by way of this. In this manner the formed guide rails  350  of the longitudinal guiding device  340  can be replaced in a simple and quick manner, for example in the case of wear or a defect. The guide rails  350  are then designed (not shown) from a plurality of formed profiles which analogously to the embodiment according to  FIG. 6 b    are arranged one after the other in manner abutting one another and are fastened on the transverse connection elements  344 . According to the embodiment according to  FIG. 6 c   , rod-like or tubular centring means  354  are provided, which in the end sections of the formed profiles abutting one another are inserted into a central profile cavity, so that as little offset as possible between the formed profiles occurs in the region of the profile butt joining. 
     A for example worn or damaged running surface  351  of a formed guide rail  350  can be replaced by another running surface  351  of the same formed guide rail  350 , on account of the design of four running surfaces  351  on the same formed guide rail  350 . For this, the formed guide rail  350  for example is separated from the transverse connection elements  344 , is rotated about the symmetry axis of the point-symmetrical cross section of the formed guide rail  350 , until a designed running surface  351  is located in a position, in which the running surface  351  to be replaced was located, and subsequently connected again to the transverse connection elements  344 . Thus parts of the conveying chain—here the runner rollers  10 —are in contact in each case with other running surfaces  351  of the same formed guide rail  350 , depending on the position of the formed guide rail  350 . Thus all four running surfaces  351  of the formed guide rail  350  can be used, which results in a fourfold greater life duration in comparison to a guide rail with only one running surface. 
     The preceding embodiments concerning the shape, fixation, release and use of formed guide rails  350  of course also applies to non-formed guide rails  341  which however externally are designed in the same manner. 
     Of course the described rolling bodies according to the  FIGS. 1 to 6  can also be fastened on the conveying member or the conveying elements (not shown) e.g. via a connection arm. 
     It is to be expressly specified at this location, that the design of the joint connection according to the embodiment examples described above is not restricted to the design of the conveying means, of the connection means to the conveying means, the runner rollers or their connection to the conveying means or a toothing, but can also be applied in differently designed chain links or conveying means. Moreover, the feature of the tool openings in the carrier elements and the associated plug-in connections are not limited to a specific embodiment of a joint connection, of a conveying element or of a runner roller. 
     The subsequently listed embodiment variants of specific design aspects on the conveying means can therefore be infinitely combined with one another:
         fastening of the runner rollers on the conveying member or on the chain links;   design of the runner rollers;   design of the joint connection;   design of the conveying member or the conveying elements   connection of the conveying elements to the chain links;   design of the longitudinal guiding device.