Abstract:
A coupling device for the releasable connection of a lifting element, in particular of a jacquard machine, to at least one lifting element of a warp thread in a weaving machine. The preferred coupling device connects a sinker cord of a jacquard machine to a harness cord of the harness of a weaving machine. The coupling device has a first coupling part assigned to the lifting element and a second coupling part assigned to the harness cord. The coupling parts execute a radial relative movement during coupling and uncoupling. The coupling device provides for rotational alignment of the two coupling parts with one another. At least one coupling part is assigned or capable of being assigned a rotational alignment mechanism. The coupling device is used in a system which rapidly connects and disconnects many connectors at the same time. The system includes a positioning mechanism for vertically moving two positioning elements which operate the coupling devices between standby and operative positions, and for horizontally moving at least one of the positioning elements to cause the coupling parts of each coupling device to interlock and disengage. The positioning elements also cooperate with portions of at least one of the coupling parts to rotationally align the coupling parts so they may interlock.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a coupling device for the releasable connection of a lifting element, in particular of a jacquard machine, to at least one lifting element of a warp thread in a weaving machine. More particularly, the invention relates to a coupling device for the releasable connection of a sinker cord of a jacquard machine to a harness cord of the harness of a weaving machine. 
     2. Description of the Related Art 
     Coupling devices of the general type referred to here are known. See U.S. Pat. No. 4,034,782, for example. These comprise two coupling parts, of which a first coupling part is assigned to the lifting element formed by a cord and a second coupling part is assigned to the harness cord. During coupling and uncoupling, the coupling parts execute in relation to one another a relative movement that is radial to the direction of displacement of the lifting element or of the harness cord. Disadvantageously, the separation and connection of the harness and the jacquard machine or of individual harness cords from and to the respective lifting elements of the jacquard machine have to be carried out manually, which takes up a relatively long period of time. Consequently, the idle times of the weaving machine are increased. 
     SUMMARY OF THE INVENTION 
     The present invention provides a coupling device which does not have the disadvantages of the prior art, such as those noted above. The coupling device of the present invention provides for automated mutual rotational alignment of the two coupling parts. At least one coupling part is assigned or is capable of being assigned a rotational alignment means. 
     Consequently, it is possible to connect and release a lifting element, for example a harness cord, or a plurality of lifting elements, in particular harness cords, for example combined in groups, quickly to and from the respective lifting element of a jacquard machine, for example. As referred to herein, a radial displacement of the coupling parts, used to disconnect the two parts, is a displacement transverse to the direction of displacement (axial direction) of the lifting elements, which is in the vertical or essentially vertical direction. 
     The rotational alignment means acts, according to a first design variant, on the coupling part constantly (FIGS. 11A to  11 C) or, according to another design variant, only during coupling and uncoupling. 
     In an advantageous exemplary embodiment of the coupling device, at least one of the coupling parts has a noncircular cross-sectional portion, over which a locating member engages for rotational alignment. Rotational alignment preferably takes place by the locating member and the one coupling part executing an axial relative movement in relation to one another. In other words, the locating member and/or the coupling part are displaced in the direction of displacement of the lifting element, and the rotational alignment of the coupling part takes place during the displacement operation or is initiated and carried out as a result of the engaging-over action. 
     In a further preferred embodiment of the coupling device, the noncircular cross-sectional portion of the at least one coupling part is twisted on itself axially, as is explained more fully below. As a result, when the cross-sectional portion engages into the locating member or tool, preferably formed by a recess or a passage orifice of a positioning element, desired rotational alignment is induced, preferably about the longitudinal center axis of the lifting element, generally hanging down vertically from the jacquard machine, of the coupling part which has the noncircular cross-sectional portion. The recess or the passage orifice may, if appropriate, also be twisted on itself, the pitch of the cross-sectional portion twisted on itself and of the recess or passage orifice being selected or mutually coordinated in such a way that self-locking does not occur when the two coupling parts are moved toward one another. 
     An exemplary embodiment of the coupling device is also preferred in which a plurality of recesses or passage orifices, which are each assigned a coupling part, are formed in the positioning element. As a result, by a displacement of the positioning element, a plurality, in particular hundreds or thousands, of lifting elements, for example harness cords, can be simultaneously separated from and connected to the respective lifting element, in particular of a jacquard machine. It is consequently possible for the harness of the weaving machine to be changed quickly, as a result of which the stoppage times of the weaving machine can be reduced. 
     Of course, in another exemplary embodiment, the reverse situation is also possible, specifically that in which the lifting elements are separated from the harness cords. For this purpose, the first coupling part executes a radial relative movement in relation to the second coupling part. 
     A further preferred embodiment of the coupling device has each of the two coupling parts assigned a positioning element. The coupling parts can thereby be aligned separately from one another axially, in the direction of the raising and lowering movement of the lifting elements, and radially, in the coupling direction and transversely to the direction of displacement of the lifting elements of the jacquard machine. 
     Finally, in a further embodiment of the coupling device, the two positioning elements have a plurality of recesses or passage orifices which, in the coupling position when the coupling device is in the coupled state, are axially in alignment with one another or offset relative to one another. Accordingly, in a first design variant of the coupling parts, at least their noncircular cross-sectional portions, over which at least one locating member engages in each case, are arranged opposite one another. In another design variant not illustrated in the figures, the cross-sectional portions bringing about rotational alignment of the coupling parts are arranged so as to be offset relative to one another, as seen in the axial direction, transversely to the coupling/uncoupling direction. 
    
    
     Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is explained in more detail below with reference to the drawing in which: 
     FIG. 1 shows a side view of an exemplary embodiment of a jacquard machine; 
     FIG. 2 shows a side view of a first exemplary embodiment of the coupling device according to the invention in the uncoupled state; 
     FIG. 3 shows a further side view of the coupling device according to FIG. 2, which is rotated through 90° in relation to the view illustrated in FIG. 2; 
     FIG. 4 shows a perspective illustration of a portion of a coupling part of the coupling device; 
     FIGS. 5A and 5B each show a top view of a locating member formed by a recess or passage orifice; 
     FIGS. 6A to  6 D in each case show a perspective illustration of two coupling parts during a coupling operation, in various functional positions; 
     FIG. 7 shows two side views of a further exemplary embodiment of a coupling device comprising two coupling parts, in the uncoupled state; 
     FIG. 8 shows two side views of the coupling parts illustrated in FIG. 7, in the coupled state; 
     FIGS. 9A to  9 E each show a side view of a coupling part capable of being connected to a harness cord; 
     FIG. 10 shows an enlarged illustration of part of the coupling part illustrated in FIG. 9C and a side view of two harness cords at their end facing the coupling device; 
     FIGS. 11A to  11 C in each case show a perspective illustration of further exemplary embodiments of the coupling device; and 
     FIG. 12 shows a side view of a substructure of a jacquard machine with a changing device for the simultaneous coupling and uncoupling of a plurality of coupling devices. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The coupling device described below may be used, in general, for the releasable connection of lifting elements, for example cords, bars or the like, that is to say of pull and/or push means. It is assumed below, purely by way of example, that the lifting elements here are those of a jacquard machine which is capable of being coupled to lifting elements of warp threads of a weaving machine, the lifting elements being formed by harness cords. 
     FIG. 1 shows a side view of an exemplary embodiment of a known jacquard machine  1  arranged above a weaving machine which is not illustrated. The jacquard machine  1  comprises a number of lifting elements  3  which are formed, here, by cords connected directly to the sinkers of the jacquard machine  1  via pulley assemblies. The lifting element used for the jacquard machine may, for example, also consist of bars or rods. The design of the jacquard machine is generally known, so that it is not described in any more detail here. 
     Each of the lifting elements  3  is releasably connected, in each case via a coupling device  5 , to one or more harness cords  7  of a harness of the weaving machine. In the exemplary embodiment illustrated in FIG. 1, the lifting elements  3  are connected in each case to three harness cords  7 , the harness cords assigned to a lifting element  3  being in each case guided through a perforation in a guide deck  9 , for example a glass grid or a perforated board. The design and functioning of the coupling devices  5  are explained in more detail below with reference to the rest of the figures. 
     FIGS. 2 and 3 each show a side view of a first exemplary embodiment of a coupling device  5  in the noncoupled state. The coupling device has a first coupling part  11  assigned to the lifting element  3  and a second coupling part  13  assigned to at least one harness cord, here altogether three harness cords  7 . The first coupling part  11  comprises, at the end at which the lifting element  3  is fastened, a noncircular oval cross-sectional portion  15 , over which a locating member  17  engages for the rotational alignment of the first coupling part. 
     In the exemplary embodiment illustrated in FIGS. 2 and 3, the locating member  17  is a passage orifice  19  which is introduced into a positioning element  21  formed by a plate. The lifting element  3 , formed by a sinker cord, tie or the like, is led through the passage orifice  19 . The passage orifice  19  has, at its edge region facing the coupling part  15 , a conical initial portion  23  which has a circular-cylindrical base area which has adjoining it a cylindrical portion  25  with an oval cross section. Alternatively, it is possible for the entire passage orifice to be of conical design. 
     The shape of the cross section of the passage orifice  19  is adapted to the shape of the noncircular cross-sectional portion  15  of the coupling part  11 . Furthermore, the cross-sectional portion  15  is twisted on itself. For rotational alignment of the coupling part  15 , the positioning element  21  displaceable in the direction of the double arrow  27  is displaced downward, so that the locating member  17  engages over the cross-sectional portion  15  of the coupling part  11 . When the coupling part  11  penetrates or engages with its cross-sectional portion  15  into the passage orifice  19 , the coupling part  11  is rotated about its longitudinal center axis. 
     The coupling part  11  has, at its end facing away from the positioning part  21 , a portion  29  of larger diameter, on which is formed a projection  31  limiting the axial movement of the coupling part  11 . In the region of the portion  29 , the coupling part  11  has a receptacle  35  which is open toward the lateral surface  33  and into which a holding projection  37  of the second coupling part  13  is capable of being introduced radially, transversely to the direction of displacement (double arrow  27 ) of the lifting element  3 . The receptacle  35  is also designed, here, so as to be open toward the bottom surface  39  of the coupling part  11 . The coupling part  11  thereby takes the form of a claw in the region of the receptacle  35 . 
     Furthermore, the receptacle  35  has a cross-sectional narrowing  41  in its lower region, so that the free space forming the receptacle is T-shaped. The shape of the receptacle and the shape of the holding projection are adapted to one another. The holding projection  37 , which is T-shaped in this exemplary embodiment, has a cross-sectionally tapered neck  43  and a cross-sectional widening  45  adjoining the neck  43  toward the free end. During the coupling and uncoupling of the coupling device  5 , the neck  43  of the holding projection  37  passes the cross-sectional narrowing  41  of the receptacle  35 . By virtue of this design, the two coupling parts  11 ,  13  are necessarily rotationally aligned and brought into a defined height position for the purpose of connecting the coupling device  5 . 
     As is apparent from FIGS. 2 and 3, the two coupling parts differ from one another only in their end regions cooperating with one another, in that one coupling part has a receptacle and the other a holding projection. For rotational alignment, a locating member  17 ′ engages over the coupling part  13 , which likewise has a noncircular, here oval cross-sectional portion  15 , the locating member being introduced in the form of a passage orifice  19 ′ in a positioning element  21 ′ displaceable in the direction of the double arrow  27 . 
     As a safeguard against the two coupling parts slipping one out of the other laterally in the coupled state, the receptacle  35  has, as seen in the radial receptacle push-in direction, on its wall region, on both sides, here altogether two projections  47  which, during coupling and uncoupling, are overcome by the holding projection  37  on the second coupling part  13  with effort in order to achieve a snap fit. In accordance with the form which the snap fit takes, the ribs  49  provided in the region of the neck  43  of the holding projection  37  engage behind the projections  47 , thereby securing the coupling device  5  against inadvertent release. During coupling and uncoupling, therefore, the receptacle, which is designed as a claw and which consists of an elastic material, for example plastic, has to be widened. In this exemplary embodiment, a further safeguard against radial displacement of the two coupling parts  11 ,  13  is provided. For this purpose, the holding projection  37  has in the region of its cross-sectional widening  45 , as seen in the radial push-in direction, a plurality of projections  47 ′ which, during coupling and uncoupling, widen the claw (the receptacle  35 ) on the first coupling part  11  in order to achieve or release a snap fit. In order to safeguard the coupling parts in the lateral direction, the ribs may have convex curvature and the corresponding recess may have concave curvature (or vice versa.). 
     A particular advantage of the radial relative movement of the two coupling parts during coupling and uncoupling is that, when the weaving machine is in operation, the axially acting tensile forces in the coupling device  5  act transversely or essentially transversely to the coupling/uncoupling direction. The forces to be exerted during coupling/uncoupling are therefore independent of the tensile forces involved in lifting the warp threads. Chamfers made on the holding projection  37  and the receptacle  35 , the chamfers not being illustrated in FIGS. 2 and 3, make it easier to couple the coupling device and at the same time give rise, in the axial and radial direction, to some tolerance compensation when a large number of identical coupling devices are actuated simultaneously. 
     During coupling and uncoupling, the oval cross-sectional portion  15 , which is introduced in the passage orifice  19  or  19 ′ during the rotational alignment of the coupling parts  11 ,  13 , absorbs the reaction forces acting transversely to the longitudinal axis or direction of displacement (double arrow  27 ) of the lifting element and additionally maintains the lateral alignment of the two coupling parts. The shape of the cross-sectional portion  15  serving for rotational alignment may, for example, also be rectangular or the like, instead of oval. It is important that the shape of the cross-sectional portion  15  makes centering or rotational alignment of the coupling part possible. The obliquely running projection  31  of the coupling parts  11 ,  13  makes it possible, moreover, to reinforce the axial centering of the coupling parts during coupling and, furthermore, makes it possible for the coupling devices arranged next to and at a distance from one another not to be capable of catching on one another when the jacquard machine is in operation. 
     FIG. 4 shows a perspective illustration of an exemplary embodiment of the noncircular cross-sectional portion  15  of the coupling parts  11 ,  13 . The portion is formed by a cone frustum which is twisted on itself at 90° about its longitudinal center axis and which has an oval cross-sectional surface. The cone frustum  53  has a small enveloping surface  55  and a large enveloping surface  57 . The longitudinal center axis of the cone frustum  53  is in alignment with the z-, z′- and z″-axis of the x-y-z/x′-y′-z′/x″-y″-z″ systems of coordinates. The small enveloping surface  55  lies in the plane spanned by the x″- and y″-axis and the large enveloping surface  57  lies in the plane spanned by the x- and y-axis. The major axis  59  of the small enveloping surface  55  is equal to or smaller than the minor axis  61  of the large enveloping surface  57  and somewhat smaller than the minor axis of the oval portion  25  of the passage orifice  19 ,  19 ′ in the positioning element  21  or  21 ′. 
     The twist of the cone frustum  53  is selected, here, in such a way that, when the cone frustum  53  is in the correct lateral position in relation to the oval portion of the passage orifice  19  or  19 ′ (see FIG.  5 A), the major axis  63  of the large enveloping surface  57  lies below the major axis of the oval portion of the passage orifice  19 ,  19 ′ in the positioning element  21 ,  21 ′, and the major axis  59  of the small enveloping surface  55  lies below the minor axis of the oval portion of the passage orifice  19 ,  19 ′. When the cone frustum  53  is arranged as illustrated in FIG. 5A, which shows a detail of the coupling device in the region of the passage orifice  19 ,  19 ′, the positioning element  21 ,  21 ′, when being displaced axially, perpendicularly to the drawing plane of FIG. 5A, can be displaced as far as a stop-forming projection  31  of the coupling part  11 ,  13 , without the latter rotating at the same time. 
     In an incorrect twisted lateral position, as illustrated in FIG. 5B, in which the cone frustum  53  is arranged so as to be twisted at 90° to the oval portion  25  of the passage orifice  19 ,  19 ′, in the case of the maximum deviation the major axis  63  of the large enveloping surface  57  lies below the minor axis of the oval portion of the passage orifice  19 ,  19 ′ in the positioning element  21 ,  21 ′ and the major axis  59  of the small enveloping surface  55  lies below the major axis of the oval portion of the passage orifice. During axial displacement of the positioning element  21 ,  21 ′, the edges of the long sides of the oval cross-sectional portion of the passage orifice slide along on the widening helix  65  of the cone frustum  53  and at the same time rotate the cone frustum  53 , and consequently the coupling part  11 ,  13 , automatically into the correct position. 
     The helix  65  illustrated on the outer surface of the oval and twisted cone frustum  53  illustrated in FIG. 4 starts at the point of intersection of the major axis of the oval enveloping surface with the contour of this surface and goes in the same direction as the rifling or twisting of the cone frustum  53 , as seen in the direction of the z-axis. When the positioning element  21 ,  21 ′ is pressed onto the cone frustum  53 , the latter is touched along such a helix and, by virtue of the spatial pitch, is centered in the radial direction and at the same time aligned in the lateral direction, that is to say radially to the displacement movement of the lifting element  3 . 
     When a longitudinal edge of a correspondingly designed recess or the like, here of the passage orifice  19 ,  19 ′, meets the helix in a twisted position of the cone frustum, at this instantaneous point of contact  67  the spatial tangent of the spiral helix  65  can be projected, on the one hand, onto the y′-z′ plane and, on the other hand, onto the x′-z′ plane, as illustrated in FIG.  4 . The point of contact  67  is located in the instantaneous cross-sectional surface  69 . The pitch of the tangent in the y′-z′ plane (pitch angle α 1 ) constitutes the pitch of the pure helix without any taper and is responsible for the rotational movement. The pitch angle α 1  is drawn against the normal N T1  of the tangent in the y′-z′ plane to the pressure force F P . Without the friction being taken into account, the rotational force F D , which points tangentially in the y′ direction on the instantaneous cross-sectional surface is obtained via the pitch angle α 1 . The pitch of the tangent in the x′-z′ plane (pitch angle α 2 ) constitutes the slant (taper) of the cone frustum at the instantaneous point of contact  67  and thereby gives rise to the centering movement. 
     The pitch angle α 2  is drawn against the normal N T2  of the tangent in the x′-z′ plane to the pressure force of the positioning element. Without the friction being taken into account, the centering force, which passes radially through the z′-axis (surface center point) in the x′ direction on the instantaneous cross-sectional surface  69 , is obtained via the pitch angle α 2 . If the positioning element first butts on the outer surface of the cone frustum at only one point of contact, when the coupling part is moved further into the passage orifice of the positioning element the coupling part is centered relative to the longitudinal center axis of the passage orifice, until the opposite sides of the cone frustum  53  come into contact with those of the passage orifice. The pressure force of the positioning element is then apportioned to both points of contact on the outer surface of the cone frustum. 
     When abutment at one point of contact takes place, the rotational movement is initiated via the rotational force, with the friction, the translational (radial compensating movement) and rotational mass moment of inertia and the polar moment of resistance of the lifting element  3  or of the harness cord or harness cords  7  being overcome. When pressure on the two opposite points of contact occurs, the pressure force is apportioned to both points of contact and the rotational movement continues positively. If friction is ignored, the rotational force F D  is obtained, as described, from the pitch angle α 1 , and the centering force is obtained from the pitch angle α 2  and, furthermore, from the instantaneous perpendicular position of the cone frustum at one or both points of contact. 
     The aligning movement of the coupling parts in the recesses or passage orifices of the positioning elements may be made easier, for example at locations where there is increased friction, by jogging, for example by means of a microstroke, or knocking the positioning element or positioning elements. 
     FIGS. 6A to  6 D show a perspective illustration of the coupling device  5  in several phases of a coupling operation. Identical parts are given the same reference symbols, so, to that extent, reference is made to the description of the previous figures. The positioning element  21 ′ cooperating with the second coupling part  13  is moved axially in the direction of the arrow  27  vertically upward in the direction of the first coupling part  11  which is rotationally aligned with the aid of the positioning element  21  and dwells in a fixed position, the positioning element  21 ′ being offset laterally relative to the longitudinal center axis of the lifting element  3  hanging down. 
     After a defined height position illustrated in FIG. 6B is reached, the lower positioning element  21 ′ is displaced in the direction of the first coupling part  11  by means of a radial/transverse movement, until the holding projection  37  on the second coupling part  13  has been moved, caught or snapped, into the receptacle  35  provided on the first coupling part  11 . 
     When the two coupling parts are in the coupled or interlocked state (FIG.  6 C), the two positioning elements  21 ,  21 ′ are moved apart from one another upward and downward respectively, as illustrated in FIG. 6D, until the distance between the two positioning elements is such that, when the jacquard machine is running, a free lifting movement of the lifting element  3  or harness cords  7  in the passage orifices  19 ,  19 ′ is possible. 
     The uncoupling operation, which is not illustrated in the figures, takes place in reverse order. In order to exchange the harness or one or more harness cords, after the jacquard machine has been stopped the positioning elements  21 ,  21 ′ are displaced downward and upward, until they butt onto the projection  31  of the coupling parts  11 ,  13 . This position corresponds to the position illustrated in FIG.  6 C. By means of a radial relative movement of the lower positioning element  21 ′, the second coupling part  13  is pressed laterally out of the first coupling part  11 . The positioning element  21 ′, together with the second coupling part  13  hanging on it, is then lowered. The positioning element  21  assigned to the first coupling part  11  remains in its position illustrated in FIGS. 6A to  6 C, which also at the same time constitutes the initial position for a new coupling operation. 
     It becomes readily apparent from what was said above that the positioning elements  21 ,  21 ′ may also be used for the simultaneous rotational alignment of a plurality of harness cords, for example combined in groups, or of all the harness cords of the harness. For this purpose, the positioning element in each case has, for each lifting element  3 , a recess or passage orifice which can be pushed over the noncircular, for example oval or rectangular cross-sectional portion  15  of the coupling part  11  or  13 , with the result that rotational alignment of the coupling part takes place. With the aid of the positioning elements  21 ,  21 ′, it is therefore possible simultaneously to couple or uncouple a plurality or all of the coupling devices connected to a lifting element of the jacquard machine. 
     FIGS. 7 and 8 each show a side view of two pictures of a further exemplary embodiment of the coupling device  5 ′ having two coupling parts  11 ,  13  which are capable of being coupled and uncoupled as a result of radial displacement. The coupling device  5 ′ is illustrated in the uncoupled state in FIG.  7  and in the coupled state in FIG.  8 . The coupling device  5 ′ differs from the coupling device  5  described with reference to the previous figures, particularly in that the coupling parts  11 ,  13 , instead of having the receptacle  35  and the holding projection  37 , each now has two, here identical hooks  71  and  71 ′ which are open to the lateral surface of the coupling parts and which can be laterally pushed one into the other perpendicularly to the drawing plane of the picture on the left in FIG.  7 . 
     During the closing of the coupling device  5 ′, the deformable tabs  73  located on the end face of the coupling parts  11 ,  13  snap into corresponding grooves  75  and  75 ′ which are introduced into the coupling parts  11 ,  13  in the region of the hooks  71 . For uncoupling, the tabs  73  have to be pressed out of the grooves  75  and  75 ′ by means of a radial relative movement of the two coupling parts  11 ,  13  in relation to one another. With the aid of the tabs  73 , the coupled coupling device is safeguarded against the two coupling parts inadvertently slipping one out of the other laterally. In the exemplary embodiment of the coupling device  5 ′ illustrated in FIGS. 7 and 8, the two coupling parts  11 ,  13  are designed identically, with the result that the costs of the coupling device can be reduced. 
     The harness cords  7  or other lifting elements for the warp threads and the lifting elements, for example a sinker cord, of the jacquard machine can be fastened to the coupling parts  11 ,  13  in various ways. FIGS. 9A-9E illustrate variants of the fastening of the harness cords  7  or of an individual harness cord to the second coupling part  13 . Of course, the first coupling part  11 , to which the lifting element (sinker cord or the like) is fastened or appropriately held, may also be designed identically. 
     In the exemplary embodiment illustrated in FIG. 9A, altogether three harness cords  7  are injection-molded directly onto the coupling part  13 . In the exemplary embodiment illustrated in FIG. 9B, a hook  77  consisting of metal or plastic is injection-molded on the second coupling part  13  or injection-molded directly together with the coupling part  13 , and a harness cord or a plurality of harness cords, which are provided, for example, with a loop at the end, can be unhooked and hung up again individually or in groups on the hooks, for example for individual repairs. By virtue of this design, it is possible, furthermore, to exchange a defective positioning element. Moreover, it is possible for the coupling part  13  itself also to be designed in its end region as a hook  79 , as illustrated in FIG.  9 C. The hook  79  is capable of being closed by means of a tongue-like closing element  81  which is likewise connected in one piece to the coupling part  13 . In the exemplary embodiment of the coupling part  13  illustrated in FIG. 9D, the latter has, on its end region cooperating with the harness cord, a downwardly open-edged U-shaped recess  83  having two lateral surfaces which are arranged parallel to one another and which are connected by means of a bolt  85 . A hook  87  connected to a harness cord  7  or to a plurality of harness cords can be suspended on the bolt  85  or, if the hook  87  is designed accordingly, snapped onto the bolt. As is evident from FIG. 9D, the U-shaped recess  83  is arranged below the aligning cone frustum (cross-sectional portion  15 ). 
     In order to simplify the exchange of the positioning element  21  assigned to the second coupling part  13 , but not illustrated in FIGS. 9A to  9 E, the second coupling part  13  of the exemplary embodiment illustrated in FIG. 9E is formed by two coupling parts  13 / 1  and  13 / 2  releasably connected to one another. The coupling part  13 / 1  has, at one end facing the first coupling part  11  (not illustrated), a holding projection  37  and, at the other end, a receptacle  35 ′, into which the holding projection  37 ′ of the coupling part  13 / 2  can be radially moved or snapped, at the other end of the coupling part  13 / 2  the latter having the cone frustum  53  for the rotational alignment of the second coupling part  13 . Of course, the other exemplary embodiments of the coupling part  13  which are described with reference to FIGS. 9A to  9 D may also have an additional coupling point of this kind, having a plurality of individual parts releasably connectable to one another. 
     FIG. 10 shows an enlarged illustration of the hook  79  which is connected in one piece to the coupling part  13  illustrated in FIG.  9 C and which is capable of being closed by means of a closing element  81 . The two pictures on the left in FIG. 10 each show the end region of a harness cord  7 , and in these end regions a connection point is injection-molded on one harness cord  7 , that on the left, in order to form a loop and a tab having a recess is injection-molded on the other harness cord located on the right. Furthermore, in order to form a loop, it is known to knot the harness cord in its end region. 
     FIGS. 11A to  11 C in each case show a perspective illustration of a further exemplary embodiment of a coupling device  5 . The coupling device  5  illustrated in FIG. 11A comprises two coupling parts  11  and  13  which each have a shank  91  formed by two round bars  93  connected to one another. The shank of the first coupling part  11  is guided by means of a passage orifice of a first positioning element, not illustrated, the passage orifice having a shaping adapted to the shaping of the shank, and the shank  91  of the second coupling part  13  is guided into a corresponding passage orifice of a second positioning element which is not illustrated. The shank  91  is thinner than the remaining regions of the coupling part  11 ,  13 . The surfaces of friction with the passage orifices of oval or rectangular cross section in the positioning elements when the jacquard machine is in operation are consequently relatively small. The cross-sectional surface of the shank  91  may, in principle, have virtually any desired design. It is necessary merely to ensure that lateral alignment of the coupling parts is maintained. It becomes clear that the coupling parts  11 ,  13  are rotationally aligned only when being introduced into the passage orifice of the positioning elements and, while the jacquard machine is in operation, remain constantly preoriented and slide back and forth in the passage orifices. The coupling device  5  is coupled and uncoupled, here too, by means of a radial relative movement of the coupling parts  11 ,  13 . 
     The exemplary embodiment of the coupling device  5  illustrated in FIG. 11B differs from the exemplary embodiment described with reference to FIG. 11A only in that the shanks  91  have an oval cross section or rectangular cross section with rounded lateral edges. 
     In the exemplary embodiment of the coupling device  5  illustrated in FIG. 11C, only the first coupling part  11  has to be rotationally aligned in order to couple the two coupling parts  11 ,  13 , since the second coupling part  13  has a holding projection  37  which is designed spherically, so that the latter can be moved or pressed into the receptacle  35  of the first coupling part  11  in any laterally rotated position of the second coupling part  13 . A shank may therefore be dispensed with in the second coupling part  13 . The shank  91  having an oval cross section is relatively thin, as compared with the shank  91  illustrated in FIG.  11 B. 
     The exemplary embodiments illustrated in FIGS. 11A to  11 C have in common the fact that the shanks  91  are somewhat longer than the maximum shared stroke. As an alternative to the shank  91 , the coupling parts  11 ,  13  may also have a guide band which engages through the passage orifice in the positioning elements, but in this exemplary embodiment the longitudinal portion of the coupling parts in which the holding projection and receptacle are respectively provided must be designed to be somewhat longer, so that this region of the coupling parts themselves can be guided in the passage orifice of the positioning elements for the purpose of absorbing the coupling forces. 
     FIG. 12 shows a side view of a jacquard machine  1  and a substructure arranged below the latter, with a changing device  94  for the simultaneous connection and release of a plurality, for example hundreds or thousands, of radially couplable/uncouplable coupling devices for harness cords  7  or the like, such as are described, for example, with reference to the previous figures. The changing device  94  comprises a plurality of, for example four, guide columns  97 , on which an upper guide frame  99  and a lower guide frame  101  are guided in the axial direction, that is to say vertically. The positioning element  21  assigned or capable of being assigned to the first coupling parts  11  is attached to the upper guide frame  99  and the positioning element  21 ′ capable of being assigned or assigned to the second coupling parts  13  is attached to the lower guide frame  101 , in this exemplary embodiment the positioning element  21 ′ being displaceable in the guide frame  101  transversely to the longitudinal extent of the guide columns  97 . It is, of course, also possible, alternatively, for both positioning elements  21 ,  21 ′ or only the positioning element  21  to be radially displaceable for coupling and uncoupling. The displacement of the guide frames  99  and  101  in the vertical direction takes place by means of a plurality of displacement arrangements which are formed, here, by piston/cylinder units  96  and which are part of an auxiliary changing device  95  arranged below the changing device  94 . The piston/cylinder units comprise, here, in each case at least two pistons extendable in the vertical direction and at least one piston extendable in the radial direction. It also remains to be pointed out that the auxiliary changing device  95 , which operates, for example, mechanically, pneumatically, hydraulically, electrically or the like, is located movably on a carriage or is arranged removably on the stand of the jacquard machine. 
     When a new harness is hung up, first the positioning element  21 ′ with the harness is moved from below, by first pistons being extended out of the cylinders, into the lower guide frame  101  and is fastened there. By means of a further vertical lifting movement of the piston/cylinder units  96 , the positioning element  21 ′ together with the guide frame  101  is raised in order to couple the coupling devices  5  and is moved from below up against the stop  103 . Finally, the positioning element  21 ′ is displaced in the guide frame  101  with the aid of the third piston displaceable in the radial direction. At the same time, the two coupling parts  11 ,  13  are pushed laterally one into the other and interlocked, so that the coupling devices  5  are closed. The second positioning element  21  attached to the upper guide frame  99  is then moved away from the stop  103  by the second pistons of the piston/cylinder units  96  being extended and is displaced upward into its position of rest illustrated in FIG.  12 . The first pistons of the piston/cylinder units  96  are subsequently retracted, with the result that the positioning element  21 ′ displaceably attached to the guide frame  101  is moved into the lower position of rest illustrated in FIG.  12 . The positioning elements  21  and  21 ′, moved apart from one another in this way, are detained in their positions of rest on the guide columns  97  by fastening means, for example quick-action locking means. In this position, when the jacquard machine  1  is in operation, the coupling devices  5  can be moved vertically within the scope of the shared stroke, without butting onto the positioning elements  21 ,  21 ′. The uncoupling of the harness from the jacquard machine, which can be carried out quickly, takes place in reverse order. 
     Instead of the mechanical stop  103 , it is also possible to employ sensors, with the aid of which the displacement movement of the guide frames can be controlled or regulated. 
     It still remains to be noted that, when the harness is unhooked from the weaving machine, the second pistons of the piston/cylinder units  96  are moved as far as the upper guide frame  99  which is arranged in its position of rest and which is then released from the guide columns  97 , lowered by means of a retracting movement of the second pistons and moved from above against the stop  103 . With the aid of the auxiliary changing device  95 , therefore, a defined displacement both of the lower guide frame  101  and of the upper guide frame  99  in the vertical direction is possible. 
     As an alternative to the exemplary embodiment described with reference to FIG. 12, in another exemplary embodiment of the jacquard machine it is possible to raise the lifting elements  3 , such as the sinker cords or the like, together with the first coupling parts attached to them, into the position in which the upper guide frame  99  is illustrated in FIG.  12 . In this exemplary embodiment, during coupling and uncoupling the upper guide frame may be fixed in its upper position of rest, so that the coupling operation can be carried out in this height position and only the lower guide frame together with the lower positioning element  21 ′ has to be moved horizontally and/or vertically. 
     Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. Therefore, the present invention is to be limited not by the specific disclosure herein, but only by the appended claims.