Conveying apparatus for conveying transporting structures

A conveying apparatus for conveying transporting structures with at least one conveying element, in particular transportation skids with a conveying runner in the automotive industry. A conveying route has at least one route unit with at least one longitudinal profile which defines a transporting direction. A drive system for the transporting structures has at least one drive device which is arranged on the at least one longitudinal profile and has at least one drive wheel which can be rotated about an axis of rotation and can be pressed, in the form of a friction wheel, against the conveying element. A bearing structure which bears the drive wheel, is mounted such that it can be pivoted about a pivot axis, and therefore the drive wheel can be moved relative to the longitudinal profile. The pivot axis of the bearing structure runs at an angle to the axis of rotation of the drive wheel.

RELATED APPLICATIONS

This application is a national phase of International Patent Application No. PCT/EP2016/070333 filed Aug. 29, 2016, which claims the filing benefit of German Patent Application No. 10 2015 012 001.8 filed Sep. 18, 2015, the contents of both of which are incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to a conveying apparatus for conveying transporting structures having at least one conveying element, in particular for conveying within the automotive industry transport skids having a conveying runner, said conveying apparatus comprisinga) a conveying track, which comprises at least one track unit having at least one longitudinal profile, which latter defines a direction of transport;b) a drive system for the transporting structures, having at least one drive device, which is disposed on the at least one longitudinal profile and comprises at least one drive wheel, which is rotatable about a rotational axis and which can be pressed as a friction wheel against the conveying element;c) a bearing structure, which supports the drive wheel and which is mounted pivotably about a pivot axis, so that the drive wheel is movable relative to the longitudinal profile.

BACKGROUND OF THE INVENTION

Conveying apparatuses of this type are used, for instance in the form of roller conveyors, for the conveyance of transporting structures. In the automotive industry, in particular vehicle bodies, or parts thereof, are transported with such conveying apparatuses between individual machining or treatment stations, such as, for instance, painting stations or dryers. The vehicle bodies, or parts thereof, are here fastened on so-called transport skids, which are known per se. These transport skids have two parallel skid runners, which during transport rest on rollers of the roller conveyor, which rollers are arranged generally in pairs, and one behind another in the direction of conveyance, on the longitudinal profiles of the conveying apparatus. A drive device comprises in practice a drivable roller, which acts on a runner of the transport skid. The drivable roller can be a supporting roller, on which the transport skid rests. Alternatively, the drive device can be configured as a friction wheel drive and comprise a drive wheel which acts laterally on the runner of the transport skid.

It must here be ensured that the drive wheel bears with sufficient force against the conveying runner of the transport skid in order to prevent unwanted slippage of the drive wheel.

In conveying apparatuses known from EP 2 523 878 B1, the bearing structure is a pivoted lever, the pivot axis of which runs parallel to the rotational axis of the drive wheel. The pivot axis of the pivoted lever and the rotational axis of the drive wheel here, in practice, run vertically, but also a solution having horizontal axes is known, wherein the axes there run in a horizontal plane perpendicular to the direction of transport. The mechanical structure is here very complex.

SUMMARY OF THE INVENTION

An object of the invention is now to provide a conveying apparatus of the type stated in the introduction, which at least offers an alternative to the known concepts and creates the possibility of a less complex structure.

This object may be achieved in a conveying apparatus of the type stated in the introduction by virtue of the fact thatd) the pivot axis of the bearing structure runs at an angle to the rotational axis of the drive wheel.

The invention is based on the recognition that it is possible by virtue of this measure, in a departure from the known concepts, to support the drive roller mechanically such that it is movable comparatively easily.

It is here particularly favorable if the angle between the pivot axis of the bearing structure and the rotational axis of the drive wheel is 90 degrees. In this case, within the limits of structural tolerances, deviations of exactly 90 degrees can occur.

Preferredly, the pivot axis of the bearing structure runs, at least with one directional component, in the direction of transport or parallel to the direction of transport. In particular in the case of a parallel path, the drive roller can be moved without a directional component in and counter to the direction of transport.

In order to ensure a reliable advancement of the transporting structure, it is advantageous if the drive device comprises a contrarotating wheel, which cooperates with the drive wheel and is mounted on that side of the longitudinal profile which lies remote from the drive wheel.

The contrarotating wheel is here preferredly mounted in a pretensioning device, by which it is biased in the direction of the drive wheel by a force means, in particular by spring force.

In a first concept, the bearing structure is configured as a swing bracket, which spans the longitudinal profile transversely to the direction of transport, wherein the drive wheel is mounted on a first end portion, and the contrarotating wheel on a second end portion, of the swing bracket.

It is favorable if the drive wheel is mounted on the swing bracket pendulously about a swing axis, and/or the contrarotating wheel is mounted on the swing bracket pendulously about a swing axis, which swing axes run parallel to the pivot axis. By virtue of this measure, the drive wheel and the contrarotating wheel can freely align themselves with the conveying runner of the transport skid, so that a contact with the running surfaces of the conveying runner is made with maximum possible surface contact.

If the drive wheel is mounted on the swing bracket pendulously about the swing axis, the pivot axis of the bearing structure can be disposed at a vertically lower level beneath the swing axis or at a vertically higher level above the swing axis. The two alternatives can be implemented, for instance, in dependence on the structural realities.

Another effective concept can be realized by configuring the bearing structure as a parallelogram guide having at least two pivot arms, which at one end are linked to the longitudinal profile pivotably about respectively a first pivot axis and at the opposite end are connected to the drive wheel pivotably about respectively a second pivot axis, wherein one of the first pivot axes defines the pivot axis of the bearing structure.

In this context and in the present case, by the term “connection” should also in principle be understood indirect connections, a direct connection of two components does not always have to be realized; this is also evident from the description of the individual illustrative embodiments.

The first pivot axes of the pivot arms can be located, in relation to a vertical center plane of the longitudinal profile, on that side of the longitudinal profile which lies remote from the drive wheel; it is then favorable if the first pivot axes are disposed at a, in the vertical direction, lower level than the second pivot axes. Preferably, the pivot arms then run beneath the longitudinal profile.

The first pivot axes of the pivot arms can alternatively also be located, in relation to a vertical center plane of the longitudinal profile, on the same side of the longitudinal profile as the drive wheel; it is then favorable if the first pivot axes are disposed at a, in the vertical direction, higher level than the second pivot axes. In both alternatives, it is then ensured that the drive roller can move due to gravity when it is not pressing against a transporting structure.

In particular, in both alternatives a pretensioning unit for the drive roller can be dispensed with.

In a further variation, it can be provided that the bearing structure is configured as a pivot bracket, which, via a pretensioning unit, is mounted pivotably about the pivot axis, wherein the pretensioning unit is arranged such that the drive wheel is moved toward the conveying element of the transporting structure.

It can here be advantageous if the pivot axis is disposed, in the vertical direction, beneath the longitudinal profile.

In a further variation, the bearing structure can be configured as a bracket, which is connected via at least one leaf spring to the longitudinal profile. An almost linear movement with only slight pivoting can here be obtained if at least one pair of two leaf springs is present.

It can be favorable if the contrarotating wheel as described above is present and is fastened separately from the bearing structure, by means of a bearing unit, to the longitudinal profile.

It is to be understood that the aspects and objects of the present invention described above may be combinable and that other advantages and aspects of the present invention will become apparent upon reading the following description of the drawings and detailed description of the invention.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail one or more embodiments with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiments illustrated.

Reference is firstly made toFIGS. 1 and 2, which respectively show a modularly constructed track unit10of a conveying apparatus12, which is designed as a roller conveyor14. The conveying apparatus12, and consequently the roller conveyor14, are built up of a plurality of such track units10. The conveying apparatus12thus defines a conveying track, which is formed of a plurality of track units10arranged one behind another.

Such a track unit10can, however, also exist in a lifting table, a rotary table, a swivel table, a lifting station, or a transverse displacement device of a conveying apparatus12, as is known per se.

InFIG. 2, a transporting structure16for objects to be conveyed, which transporting structure rolls down on the roller conveyor14, is additionally shown. In the present illustrative embodiment, this is a transport skid18as is used in the automotive industry and on which, in a manner which is known per se, one or more objects to be conveyed can be fastened; these include, in particular, vehicle bodies, or parts or add-on parts thereof. In the case of a vehicle body, a transport skid18generally receives a vehicle body, whereas smaller objects, such as, for example, add-on parts, are accommodated in once again dedicated transport racks, which are then, for their part, fastened on the transport skid18. As can be seen inFIG. 2, the transporting structure16comprises as the conveying elements two parallel runners20,22, which are connected to each other by transverse members24.

The roller conveyor14is designed, in particular, for the materials-handling connection of machining or treatment stations, in which the objects are moved with dedicated materials-handling systems which are tailored to the environmental conditions prevailing in the machining or treatment stations.

A track unit10of the roller conveyor14comprises two longitudinal profiles26,28, which are arranged parallel to each other on supporting frames30and are fastened to these, and thus define the direction of transport32of the transport skid18. The direction of transport32is illustrated by an arrow, the arrow tip of which, inFIGS. 3 to 5 and 7 to 12, is respectively illustrated by a circle with dot where the direction of transport32runs perpendicular to the plane of the paper toward the observer.

In the present illustrative embodiment, two supporting frames30per track unit10are provided, though also more than two track units30can be used for a track unit10.

When direction specifications such as laterally, at the top, at the bottom, vertically, horizontally or the like are used, these always relate to the components in a roller conveyor14installed at the installation site.

In the longitudinal profile26, the outer side flank is denoted by26a, the opposite side flank by26b, the top side, i.e. the conveying side, by26c, and the bottom side by26d.

The supporting frames30respectively comprise two supporting feet34, which are fastened to opposite ends of a connecting profile36and via which the supporting frames30can be anchored to the floor of the site of operation of the roller conveyor14. The longitudinal profiles26,28of the roller conveyor14are respectively detachably connected to the supporting frame30with the aid of a supporting frame fastening device38.

The conveying apparatus12comprises guide brackets40, more than one of which are detachably fastened at regular intervals to one of the longitudinal profiles26,28; in the present illustrative embodiment, this is the longitudinal profile26. The further components of the guide brackets42are inFIGS. 1 and 2provided with reference symbols only in respect of respectively one guide bracket42. A guide bracket42comprises a supporting roller42, on which the runner20of the transporting structure16can run down. Furthermore, a guide bracket42comprises two guide rollers44for the lateral guidance of the transporting structure16, of which one presses against the outward pointing outer side flank20a, and the other against the inner side flank20b, pointing toward the inside of the skid, of the runner20of the transport skid18, when said runner is in the region of the guide bracket40and is running down on the supporting roller42, as can be seen inFIG. 2. During operation, the rotational axis of the supporting roller42thus runs horizontally and transversely to the longitudinal members26,28, and the rotational axes of the guide rollers44run vertically. The guide brackets40are detachably fastened by means of a respective guide bracket fastening device46to the longitudinal member26.

The distances between two adjacent guide brackets40are geared to the length of the transport skid18in such a way that its runner20is guided always by at least three guide brackets40; this is illustrated byFIG. 2. In practice, it is sufficient if the transport skid18is guided always by two guide brackets40.

The conveying apparatus12further comprises supporting brackets48, of which several are detachably fastened at regular intervals to one of the longitudinal profiles26,28; in the present illustrative embodiment, this is the longitudinal profile28. The supporting brackets48respectively comprise a supporting roller50and are fastened to the longitudinal member28with the aid of a supporting bracket fastening device52.

The supporting brackets48are designed such that the runner22of the transport skid18, which runner rolls down on their supporting rollers50, can move to the side without disturbance of the movement of the transport skid18. The distances between the runners20,22of various transport skids18can turn out to be different, due to structural tolerances. Since one runner20in the guide brackets40is always guided in such a way that a movement to the side is prevented, these tolerances on the part of the supporting brackets48can be compensated, since the second runner22can there run off to the side without hindrance.

The distances between two adjacent supporting brackets48are geared to the length of the transport skid18in such a way that its runner22always rests on at least three supporting brackets48; this is again illustrated byFIG. 2. In practice, it is sufficient if the transport skid18is always guided by two supporting brackets48.

Furthermore, the conveying apparatus12comprises, in total, a drive system54for the transporting structures16, said drive system having at least one drive device56, which, during operation of the conveying apparatus12, is disposed on one of the longitudinal profiles26,28. The drive device56operates as a friction wheel drive. It is configured as a drive module58, which can be detachably fastened to a longitudinal profile26,28. In practice, the drive module58is attached to the same longitudinal profile26,28which also bears the guide bracket40; in the present illustrative embodiment, this is the longitudinal profile26of the roller conveyor14.

The conveying apparatus12comprises a plurality of drive devices56in the form of such drive modules58, wherein the distance between two adjacent drive modules58is tailored such that a conveying structure16is always driven by at least one drive module58.

A drive module58comprises a drive unit60having a drive wheel62, which latter is mounted rotatably about a rotational axis64and can be pressed as a friction wheel against the conveying runner20of the transport skid18. The drive unit60further comprises a transmission block66and a motor68, which drives the drive wheel62via the transmission block66. The motor68is an electric motor and is supplied with energy and control signals in a manner which is known per se.

The drive module58comprises a drive fastening device70and can be detachably fastened with the latter to the longitudinal profile26. To this end, the drive fastening device70comprises a bearing cheek72of C-shaped cross section, which embraces the longitudinal profile26and supports a bearing structure74, which latter, for its part, movably supports the drive unit60and, in this way, the drive wheel62. The bearing cheek72is on the opposite side of the longitudinal member26bolted to a counterplate (not specifically shown) or the like and is in this manner clamped against the longitudinal member26and fastened thereto. In one variation (not specifically shown), the bearing cheek72can embrace, from the top side, the longitudinal profile26. Where appropriate, components, which are detailed further below, must then be fastened to the bearing cheek72such that they are offset by 90° via angle supports. The bearing cheek72can also be plate-shaped and bear only against the side flank26aof the longitudinal member26.

The drive module58further comprises a contrarotating wheel76, which is mounted on that side of the longitudinal profile (26) which lies remote from the drive wheel62and, situated opposite the drive wheel62, bears against the inner face20bof the conveying runner20of the transport skid16when this is in the region of the drive device56. The contrarotating wheel76is mounted about a rotational axis78in a pretensioning device in the form of a pretensioning block80, by which it is biased by means of spring force in the direction of the drive wheel62. The distance between the drive wheel62and the contrarotating wheel76is here, given the maximum deflection of this same in the direction toward the drive wheel62, smaller than the thickness of the conveying runner20of the transport skid18, so that the contrarotating wheel76is always pressed outward counter to the spring force whenever the conveying runner20passes between the drive wheel62and the contrarotating wheel76.

When the drive wheel62and the contrarotating wheel76bear against the runner20of a transport skid18, their rotational axes64and78, respectively, run broadly vertically.

The bearing structure74, which supports the drive wheel62, is, for its part, mounted pivotably about a pivot axis82which runs at an angle to the rotational axis64of the drive wheel62, whereby the drive wheel62can be moved relative to the longitudinal profile26. In all below-described illustrative embodiments, this angle is 90°, though variations having an angle different than 90°, which angles are greater than 0°, may also be considered. In all below-described illustrative embodiments, the pivot axis82runs, moreover, parallel to the conveying direction32, though variations therefrom, in which the pivot axis82of the bearing structure74is not parallel to the conveying direction32, in which the pivot axis82of the bearing structure74runs at least with one directional component in the direction of transport32, may also be considered in this regard.

FIGS. 3 to 11now show five different illustrative embodiments of drive modules58, which are there respectively denoted by58.1,58.2,58.3,58.4and58.5. The respective bearing structures74there bear the reference symbols74.1,74.2,74.3,74.4and74.5. Mutually corresponding components bear the same reference symbols. InFIGS. 1 and 2, the drive module58.4is respectively shown with the bearing structure74.4according toFIGS. 8 and 9.

In the drive module58.1according toFIGS. 3 and 4, two parallel supporting arms84, of which only one is visible, project outward from the bearing cheek72in relation to the longitudinal profile26. The other of these supporting arms84is located behind the plane of the paper, behind the drive unit60. At their end lying remote from the outer side flank26aof the longitudinal profile26, the two supporting arms84support the bearing structure74.1pivotably about the pivot axis82. The bearing structure74.1is configured as a swing bracket86, which spans the longitudinal profile26of the roller conveyor14transversely to the direction of transport32. The swing bracket86has two mutually connected parallel, U-shaped bracket cheeks88, of which again only one is discernible and the other is disposed behind the plane of the paper, behind the drive unit60. The two bracket cheeks88are coupled, at a first end portion88a, with the drive wheel62. For this purpose, the end portions88areceive the drive unit60articulately between them. In the present illustrative embodiment, the drive unit60—and in this way the drive wheel62—is mounted pendulously about a swing axis90which runs parallel to the pivot axis82of the bearing structure74.1. As a result of the weight of the transmission block66and of the motor68, the drive wheel62, irrespective of the position of the swing bracket86, remains oriented broadly such that its rotational axis64runs vertically.

At the opposite second end portion88b, the bracket cheeks88receive the pretensioning block80, and hence the contrarotating wheel76, between them, wherein this too is pendulously mounted about a swing axis92which runs parallel to the pivot axis82of the bearing structure74.1. In the case of the contrarotating wheel76, mechanical stops (not specifically shown) are present, which delimit the pivoting of the contrarotating wheel76about the swing axis92.

FIG. 3shows a situation in which the conveying runner20of the transport skid18is in the region of the drive module58.1. When the conveying runner20passes with its, in the direction of transport32, front end between the drive wheel62and the contrarotating wheel76, the contrarotating wheel76is firstly pressed outward counter to the bias until the spring force offers too great a resistance and pivots the swing bracket86about the pivot axis82. As a result of the swing mounting, the drive roller62and the contrarotating wheel76are here oriented such that they bear full-facedly against the side flanks20aand20bof the conveying runner20.

As can be seen inFIG. 2, the side flanks20a,20bof the conveying runner20, and its running surface on the bottom side, converge in a, in the direction of transport32, front end portion20c, so that the conveying runner20, in the end portion20c, tapers in the direction of transport32. The second conveying runner22of the transport skid18is correspondingly configured. It is hereby avoided that the drive roller62or the contrarotating wheel76suffers a shock when the transport skid18passes into a drive module58. In some embodiments (not specifically shown), also just the side flanks20a,20b, or perhaps all outer faces, i.e. including the outer face on the top side of the conveying runner20, can converge in the direction of transport32.

Once the transport skid18has passed through the drive module58.1, the swing bracket86pivots back again. For the limitation of the pivot path of the swing bracket86in the outward direction, a mechanical stop (not specifically shown) is present.FIG. 4shows this situation, in which the swing bracket86is pivoted as far as possible to the right about the pivot axis82.

In the case of the drive module58.1, the pivot axis82of the bearing structure74.1lies at a vertically lower level beneath the swing axes90and92of the drive unit60and of the contrarotating wheel76, respectively.

In the drive module58.2according toFIG. 5, the pivot axis82of the there-situated bearing structure74.2is located at a vertically higher level above the swing axes90and92. For this purpose, the bracket cheeks88of the swing bracket86comprise an end portion88aextended beyond the pivot mounting of the drive unit60on the swing bracket86. Via this end portion88a, the bearing structure74.2is mounted above the swing axis90of the drive unit60, pivotably about the pivot axis82, on the supporting arm84, for which purpose the supporting arm84extends upward at appropriate distance from the bearing cheek72.

In the drive module58.3according toFIGS. 6 and 7, the drive wheel62is not swing-mounted, but is fastened to the longitudinal profile26with the aid of a parallelogram guide94. For this purpose, the bearing cheek72bears on its bottom side two vertically downward protruding supporting cheeks96, of which only one is discernible. The other supporting cheek96is located behind the plane of the paper. The supporting cheeks96respectively support two pivot arms98of the parallelogram guide94, which are pivotable on the supporting cheeks96about a first pivot axis100and extend in the direction of the drive unit60. At the ends lying remote from the first pivot axes100, the pivot arms98are hinge-fastened to the drive unit60pivotably about a respective second pivot axis102and are in this way hinge-connected to the drive wheel62.

In the present illustrative embodiment, the pivot arms98run beneath the longitudinal profile26; their first pivot axes100are located, in relation to the vertical center plane of the longitudinal profile26, on that side of the longitudinal profile26which lies remote from the drive wheel62. The pivot arms98thereby cross the path of movement of the conveying runner20of the transport skid18. In this case, the first pivot axes100on the supporting cheeks96are disposed at a, in the vertical direction, higher level than the second pivot axes102on the drive unit60.

In one variation (not specifically shown), the first pivot axes100of the pivot arms98can also be disposed, in relation to the vertical center plane of the longitudinal profile26, on the same side as the drive unit60or the drive wheel62. In this case, the first pivot axes100on the supporting cheeks96are disposed at a, in the vertical direction, lower level than the second pivot axes102on the drive unit60.

In this illustrative embodiment, the bearing structure74.3for the drive wheel62is formed by pivot arms98of the parallelogram guide94, wherein the pivot axis82of the bearing structure74.3is defined by one of the pivot axes100on the supporting cheeks96. The pivot axes100and the pivot axes102run parallel to one another.

Unlike the drive modules58.1and58.2, in which the contrarotating wheel76is likewise supported by the respective bearing structure74.1and74.2, in the drive module58.3the contrarotating wheel76is separated from the bearing structure74.3in the pretensioning block80and is here fastened in a positionally fixed manner to the longitudinal profile26with the aid of a bearing unit104. Nor, in this case, is the contrarotating wheel76swing-mounted.

Once a transport skid18has passed through the drive module58.3, the drive unit60moves downward due to gravity. In order that the drive unit60can move only up to a defined lower position, the drive unit60bears a stop element106, which extends over the top side26cof the longitudinal profile26. The drive unit60can thereby move into a lower position only to the point where the stop element106rests on the top side26cof the longitudinal profile26or on the there-situated part of the bearing cheek72, as is illustrated byFIG. 7.

The parallelogram guide94is designed such that the distance between the drive roller62and the contrarotating roller76is smaller in this lower position of the drive unit60than in a higher position of the drive unit60.

When a transport skid18now passes into the drive module58.3, its conveying runner20forces the drive wheel62outward. The drive wheel62can escape this force influence by way of a corresponding upward movement of the drive unit60. The parallelogram guide94ensures that the drive wheel62, during its movement, remains always horizontally oriented with vertical rotational axis64and in this way always bears vertically, linearly or full-facedly, against the side flank26aof the longitudinal profile26.

In the drive module58.4according toFIGS. 8 and 9, the there-situated bearing structure74.4is not configured as a parallelogram guide, but as a pivot bracket108, which is rigidly coupled with the drive unit60and, in the vertical direction beneath the longitudinal profile26, is mounted on the supporting cheeks96on the bottom side of the bearing cheek72, via a pretensioning unit110, pivotably about the pivot axis82. The pretensioning unit110is arranged such that the drive unit60is acted upon with a spring force in such a way that the drive wheel62is moved toward the conveying runner20of the transport skid18. Thus the drive wheel62is moved toward the contrarotating wheel76when there is no transport skid18in the region of the drive module58.4; this is illustrated byFIG. 9. The stop element106limits in this case the movement of the drive wheel62toward the contrarotating wheel76. The rotational axes64and78of the drive wheel62and of the contrarotating wheel76are in this case no longer parallel.

When a transport skid18passes into the drive module58.4, the drive wheel62is pushed outward by the conveying runner20, whereby the drive unit60pivots outward counter to the spring force of the pretensioning unit110about the pivot axis82and, as a result of the spring force of the pretensioning unit110, presses against the side flank20aof the conveying runner20.

In the drive module58.5according toFIGS. 10 and 11, the there-situated bearing structure74.5is formed by a bracket112of C-shaped cross section, which, from the side flank26aof the longitudinal profile26, embraces the bearing cheek72. The bracket112is rigidly coupled with the drive unit60and connected via leaf springs114to the bearing cheek72, which leaf springs allow the bracket112, and hence the drive unit60, to pivot in relation to fastening ends114aof the leaf springs114to the bearing cheek72. The fastening ends114aand the opposite fastening ends114bof the leaf springs114are provided with reference symbols only inFIG. 11.

In this illustrative embodiment, the pivot axis82of the bearing structure74.5is a virtual pivot axis, which is defined by one of the fastening ends114aof the two leaf springs114to the bearing cheek72.

When the transport skid18passes into the drive module58.5, its conveying runner20exerts on the drive wheel62a force by which the bracket112, and hence the drive unit60, is moved outward. As a result of the restoring force of the leaf springs114, the drive wheel62presses always against the side flank20aof the conveying runner20.

In the drive module58.5, the leaf springs114run vertically in the sense that their opposite fastening ends114a,114bare spaced apart in the vertical direction, but not in the horizontal direction.

In one variation (not specifically shown), the drive unit60is fastened via one or more leaf springs to the bearing cheek72, wherein the leaf springs run horizontally in such a way that their opposite fastening ends are spaced apart in the horizontal direction, but not in the vertical direction.

It is to be understood that additional embodiments of the present invention described herein may be contemplated by one of ordinary skill in the art and that the scope of the present invention is not limited to the embodiments disclosed. While specific embodiments of the present invention have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention, and the scope of protection is only limited by the scope of the accompanying claims.