Carriage for a conveyor, in particular for a gravity conveyor, conveyor system and method for operating a conveyor system

Description

Technical area

[0001] The present invention relates to the conveyance of goods. It relates to a carriage for a conveyor, in particular for a gravity conveyor, a conveyor system, in particular a gravity conveyor system, and a method for operating a conveyor system, in particular a gravity conveyor system. State of the art

[0002] Automated goods handling plays an important role in the production and post-processing of goods, as well as in the picking and packing of orders. Gravity conveyors, especially overhead gravity conveyor systems, are characterized, among other things, by the fact that they allow goods to be moved from the floor to otherwise unused areas inside or outside buildings. Overhead conveyor systems are therefore often mounted overhead on supports attached to the ceiling, walls, or individual columns fixed to the floor.

[0003] Overhead conveyor systems are also used as buffers between two or more work processes with different speeds. This allows networked processes to be decoupled temporally and / or spatially, allowing, for example, process disruptions to be rectified without having to stop the other parts of a process chain. They can also be used to compensate for cycle time differences in processing.

[0004] Gravity overhead conveyors are particularly suitable for buffer construction in many applications. This is partly due to the aforementioned improved use of space. On the other hand, they are relatively energy-efficient because, unlike forced-conveyor systems, they do not require drive mechanisms such as drive chains running along the rails and usually have only a few short, forced-conveyor sections. This also allows gravity overhead conveyors to be scaled down or expanded relatively easily and cost-effectively to meet changing production requirements.

[0005] For the safe operation of gravity overhead conveyors, it is important that the transport bodies used (also called trolleys) have consistently good running characteristics. In particular, it must be ensured that transport bodies do not accidentally slow down or even come to a stop on gravity-conveyed sections of the conveyor, as this would lead to delays or interruptions in the conveyor process. Therefore, trolleys with wheels or rollers are usually used as transport bodies for gravity overhead conveyors, as these generally have lower resistance to movement than those with so-called sliders, which in turn have a speed-dependent resistance to movement.

[0006] Different types of carriages are known in the state of the art, in which the wheels or rollers are aligned to the loads occurring during conveying.

[0007] WO2016030274A1 by the same applicant describes, among other things, a rail-conveyed conveyor comprising a conveyor carriage with at least one first, second, and third roller along a rail guide. The rotational planes of the at least first, second, and third rollers are to be arranged at an angle of greater than 0° and less than 180° relative to one another. To prevent a tipping moment in the conveying direction of the conveyor carriages moved independently of one another along a conveyor line, an arrangement of two or more first, second, and / or third rollers is provided. A conveyor system with such conveyors is also described. The same applicant shows a system for buffering goods during production on the internet, which is related to the aforementioned international application. This system is suitable for a wide variety of applications.However, in some specific applications it may be necessary to adjust the carriages, rail type and rail path specifically to the material being conveyed in order to achieve an optimal result.

[0008] EP 0 856 480 A1 describes a rail-guided transport device, particularly for conveying printed products, as well as a transport system with such transport devices. The transport device comprises several wheels resting on two sides of a guide rail. Movements transverse to the conveying direction are to be prevented by means of a flange attached to the wheels. According to the description, the transport device is to be mounted and guided on the guide rail with virtually no play by means of offset wheels or sliding means.

[0009] US 4,531,460 shows a material transport system that is also suitable for the suspended transport of heavy goods. It describes carriers that comprise at least two mechanically connected carrier heads. One head can serve as the drive head and the second head as the idler head. The two carrier heads each have support wheels that run on horizontal running surfaces of a support rail. In addition, the carrier heads have smaller guide rollers rotating around vertically arranged axes. The carriers are constructed from a relatively large number of components. Furthermore, they cannot absorb torques transverse to the direction of travel, but only those around axes parallel to the direction of travel and those around vertical axes perpendicular to the direction of travel.

[0010] EP 0 291 622 B1 discloses a rail for guiding a drive chain in a conveyor belt system for handling individual objects, with which the objects can be moved along selectable paths. The rail is intended to comprise a plurality of prefabricated, detachably interconnected modules, each module forming a section with a square cross-section. According to the document, the modules are intended to consist of straight and curved modules, with only one type of curved module being available, and the radius of curvature of the curved modules being determined by the smallest curve radius of the drive chain used. On each of its four sides, a guide matching the corresponding drive chain is arranged on each module.In this way, ascending or descending paths as well as curves can be created with one type of curved module by rotating it and arranging the drive chain apparently in the respective vertically downward-facing guide. The guides not occupied by the drive chain are intended, as shown, to accommodate connectors between multiple modules. EP0456978A1 relates to a conveyor provided with a track having a running surface and with several running gears with rollers. It also has traction means comprising a traction element attached to the running gears. To simplify assembly and ensure quiet operation, it is proposed that the running surface of the track for the running gear rollers be made of plastic.

[0011] US4248157A discloses a carriage according to the preamble of claim 1.

[0012] It has been found that in existing systems, where the carriages must move forward on their own, driven by gravity, obstructions to the carriage's movement occur primarily where the path includes spatial curves. Such obstructions, which also depend on the type of goods being transported, can significantly impair the operation of such a conveyor system. Description of the invention

[0013] It is therefore an object of the invention to provide a reliable carriage, particularly for a gravity conveyor system. Such a carriage should be suitable for goods of different dimensions and / or masses, as well as for conveyor lines with virtually any desired track layout.

[0014] It is a further object of the invention to provide a carriage that can be manufactured at a relatively low unit price.

[0015] Another object of the invention is to provide a functionally reliable and simple conveying system, in particular a gravity conveying system.

[0016] A further object of the invention is to provide an advantageous method for operating such a conveyor system.

[0017] These and other objects are achieved by claims 1, 13 and 15.

[0018] Embodiments of the invention emerge from the dependent claims.

[0019] The carriage according to the invention according to claim 1 for a rail-guided conveyor system, in particular a gravity conveyor, comprises: a) a carriage body designed to engage around a guide rail, said carriage body comprising a first and a second leg which are connected to one another by a transversely extending connecting section, wherein b) the first leg has first rollers mounted on its inside and c) the second leg has second rollers mounted on its inside and d) the connecting section has third rollers mounted on its inside, e) the first and second rollers are arranged upright and f) the third rollers are arranged horizontally.

[0020] When mounted on a guide rail, a carriage can also be rotated at least temporarily, so that, for example, during such a rotation of 90°, the first and second rollers can be arranged horizontally and the third rollers can be arranged vertically.

[0021] One design of the carriage is characterized by the fact that the carriage has a U-shaped cross-sectional profile.

[0022] A carriage according to the invention can be used for a gravity overhead conveyor. Due to its special properties, a carriage according to the invention can only be mounted suspended from a guide rail. With a correspondingly aligned guide rail, a carriage design can also run upright on or alongside a guide rail as an alternative to the invention. Orientations in between are also possible.

[0023] A design of the carriage according to the invention is characterized in that means for conveying objects in a suspended or supporting manner are attached to the connecting section. A carriage can thus be located at least temporarily above, to the side, or below an object being conveyed.

[0024] In one embodiment of the carriage, it comprises a plate mounted on the connecting section as a means for supporting the conveyance of objects. Such a plate can be a single plate. However, such a plate can also be an arrangement of several plates mounted on one and / or several carriages, as will be explained in more detail later.

[0025] According to the invention, the first and second rollers are arranged mirror-symmetrically to a vertical plane of symmetry of the carriage.

[0026] According to the invention, the axes of rotation of the third rollers lie in the vertical plane of symmetry of the carriage.

[0027] The carriage according to the invention is characterized in that the first and second rollers as well as the third rollers are each provided in pairs, wherein the rollers of a pair are each arranged one behind the other in the running direction of the carriage.

[0028] In particular, the axes of rotation of each assigned pair of rollers can have the same distance from each other.

[0029] Optionally, the axes of rotation of the rollers of a first roller set, comprising a first and a second and a third roller, may lie in a first plane and the axes of rotation of the rollers of a second roller set, also comprising a first and a second and a third roller, may lie in a second plane, wherein the first plane is parallel to the second plane.

[0030] It has been shown that, in certain applications, such an arrangement of two roller sets can achieve particularly precise and reliable guidance. In particular, it can ensure that even with sharp curves in the trajectory of a conveyor line, there is no risk of jamming between the rollers and the guide rail. It also prevents the carriage from undesired lurching and / or vibrating. This ensures even loading of the rollers and smooth carriage travel.

[0031] A further embodiment of the carriage is characterized in that the first and second rollers have a diameter of 10-50 mm and a width of 5-25 mm.

[0032] Another design of a carriage is characterized in that it comprises a first set of rollers with a first, a second and a third roller, all of which have the same diameter and the same width. The axes of rotation of the rollers of the first set of rollers lie in a first plane. Such a design of a carriage is also characterized in that it comprises a second set of rollers with a first, a second and a third roller, all of which have the same diameter and the same width. The axes of rotation of the rollers of this second set of rollers lie in a second plane. In such a design of a carriage, the first plane lies parallel to and at a distance from the second plane. It has been shown that with such a design of a carriage, particularly safe conveying can be achieved even on conveyor lines with very sharply curved trajectories.

[0033] Another design of the carriage is characterized in that the third rollers and the first and second rollers have the same dimensions. This can be advantageous for reducing the number of different components of a carriage, which simplifies their production and—also due to the simplified inventory management it enables—can make them more cost-effective.

[0034] Yet another embodiment of the carriage is characterized in that the second rollers and / or first and second rollers are designed as ball bearings overmolded with a roller body.

[0035] A further embodiment of the carriage is characterized in that the first and second rollers and the third rollers are detachably attached to the carriage body, in particular, they are screwed to the carriage body or to the carriage body. This allows, for example, simplified replacement of defective rollers. However, other types of connections are also conceivable.

[0036] Another embodiment of the carriage is characterized in that the carriage body is formed in one piece.

[0037] Yet another embodiment of the carriage is characterized in that the carriage has at least one coupling element arranged on the first or second leg or the connecting section in an outwardly projecting manner for at least temporary coupling to a device for accelerating or uniformly moving or braking the carriage.

[0038] In particular, the first and second rollers are provided in pairs, with the rollers of each pair being arranged one behind the other in the running direction of the carriage, and the at least one coupling element being arranged between the rotational axes of the first or second rollers. Such an arrangement can be advantageous for minimizing pitching moments that occur when two carriages collide. Furthermore, the carriage can have two coupling elements that are arranged mirror-symmetrically to the vertical plane of symmetry.

[0039] A further embodiment of the carriage is characterized in that the carriage has at least one elastically deformable buffer body projecting outward from the carriage body in a running direction of the carriage for cushioning contact with a second carriage. In particular, the carriage can have at least one central buffer body mounted centrally on the connecting section. This can prevent, for example, damage when the connecting sections of successive carriages collide. This can be advantageous, for example, for guide rails with a continuously decreasing gradient.

[0040] Another embodiment of the carriage is characterized in that the carriage has coupling means with which it can be connected to at least one other carriage. This allows the formation of an interlinked carriage arrangement. Depending on the application, such interlinked carriage arrangements can comprise a few carriages (e.g., 2, 3, or more) or a large number of such carriages (e.g., 10, 20, or more). Such interlinked carriage arrangements can also be endless (closed) or quasi-endless (very long) chains, as will be explained in more detail later.

[0041] Depending on the application area of the carriage, these can be connected to the coupling means in a detachable or non-detachable manner.

[0042] Coupling means can be mechanical coupling means, e.g. hooks and eyes, cardan joints or ball joints, but can also be magnetic coupling means or adhesives.

[0043] A connection between carriages created by such coupling devices can be rigid or articulated, for example, to ensure the necessary mobility of the individual carriages when cornering. The connection can also include additional elements such as connecting rods, springs, or spring-damper elements, for example, to specifically adjust the kinematic coupling of connected carriages to a specific application.

[0044] In particular, the carriage may have at least one elastically deformable buffer body projecting outward from the carriage body in a running direction of the carriage for cushioning contact with a second carriage, wherein the coupling means may be integrated into the buffer body. For some applications, the buffer bodies of a first and an adjoining second carriage may be formed integrally, wherein the coupling means may, for example, be a thin section designed as a hinge or joint.

[0045] The conveyor system according to the invention, in particular a gravity conveyor system, comprises at least one guide rail and at least one carriage according to one of claims 1 to 12, wherein the guide rail and the carriage are coordinated with one another and the guide rail is encompassed by the carriage. One embodiment of the conveyor system, in particular a gravity conveyor system, is characterized in that several carriages are provided, that some of the carriages are designed as transport carriages and can be loaded with transported goods, and that another part of the carriages is designed as spacer carriages and can be used to ensure a distance between the transport carriages.

[0046] The method according to the invention for operating a conveying system according to claim 15, in particular a gravity conveying system, according to the invention is characterized in that a plurality of carriages is provided, and a part of the carriages is equipped with transport goods and another part of the carriages is empty and is used to form a distance between the carriages equipped with transport goods.

[0047] One embodiment of the method is characterized in that the carriages loaded with transport goods and the empty carriages used to create a gap between them are coupled together. Depending on the application, this coupling can be detachable or non-detachable.

[0048] One embodiment of the method is characterized by the fact that several carriages are linked to form at least one coupled carriage arrangement. Such a carriage arrangement or linked unit can, for example, comprise between 2 and 20 carriages. However, linked units with more carriages are also conceivable.

[0049] A further embodiment of the method is characterized in that the load of at least one conveyed item is distributed across multiple carriages of the at least one coupled carriage arrangement. This can be achieved, for example, by mechanically connecting a transported item to multiple carriages simultaneously, e.g., by attaching it to them. In this way, even particularly heavy items can be conveyed, for example, since the resulting loads can be distributed across the multiple carriages.

[0050] A carriage according to the invention, particularly for a gravity conveyor, is particularly suitable for a guide rail as described in detail in a parallel Swiss patent application filed by the same applicant. However, a carriage according to the invention is not fundamentally limited to use with such guide rails.

[0051] In the past, it has been shown that under certain load conditions, the rollers of carriages for gravity conveyors align themselves relative to the guide rail in such a way that the latter's resistance to movement increases significantly. On the one hand, it can happen that rollers leave the actual running surfaces of a guide rail and instead contact surfaces with significantly higher rolling resistance.

[0052] On the other hand, it is also possible that the contact forces between the rollers and treads are greatly increased, which can also result in a significant increase in rolling resistance.

[0053] Likewise, due to certain external forces, a carriage may be aligned relative to a guide rail in such a way that the guide rail becomes jammed against the carriage body and / or the rollers, causing the carriage to slow down. This may interrupt conveyance at least temporarily and / or damage the carriage or guide rail.

[0054] In the case of gravity overhead conveyors in particular, (translational) forces in the direction of travel (x), forces horizontally lateral to the direction of travel (y) and forces in the vertical direction (z) act on a carriage. In addition, however, different torques also act on a carriage, which are caused in particular by accelerations of the conveyed material, but also of the carriage itself, during transport along the conveyor track. Such accelerations occur mainly during horizontal and vertical changes of direction and during braking or increases in speed. For many types of rail, pitching moments, i.e. torques about axes aligned laterally to the direction of travel (y), have proven particularly problematic. However, depending on the material to be conveyed and the route of the rail track, yaw moments, i.e. torques about axes vertical to the direction of travel (z), can also be problematic.The same applies to rolling moments, i.e. torques about axes (x) aligned parallel to the direction of travel.

[0055] A carriage according to the invention, thanks to specially arranged rollers matched to a guide rail, can withstand the forces and torques occurring both individually and in any combination. This reliably prevents jamming of the carriage and guide rail.

[0056] For this purpose, a carriage according to the invention for a gravity conveyor comprises a carriage body designed to engage around a guide rail. Such a carriage body has a first and a second leg connected by a connecting section. According to the invention, first and second rollers are mounted on the inside of the first leg and on the inside of the second leg. Third rollers are mounted on the inside of the connecting section. According to the invention, the first and second rollers are arranged vertically, whereas the third rollers are arranged horizontally.If such a carriage is used in a gravity conveyor, for example, a gravity overhead conveyor, the first and second rollers primarily carry the vertical load, thus serving as support rollers, while the third rollers primarily guide the carriage horizontally, thus acting as guide rollers. However, the rollers can temporarily change these functions and / or swap positions, as explained in more detail later. This can be the case, for example, when accelerations occur transverse to the running direction in curved sections or when the guide rail is rotated about its longitudinal axis.

[0057] Carriages according to the invention exhibit particularly good properties when used in combination with guide rails which have essentially horizontal, parallel and oppositely directed surfaces which can serve as running surfaces for the support rollers and which also have essentially vertical, parallel and oppositely directed surfaces which can serve as running surfaces for the guide rollers.

[0058] Means for conveying transported goods (tubes, bottles, cartons, boxes, etc.) can be attached to the connecting section of a carriage. This conveyance can be carried out, for example, in a suspended or supporting manner. However, within the scope of the invention, it is also possible for carriages to lack such means for specific reasons, as will be explained in more detail later.

[0059] The guide rollers serve, on the one hand, to guide the carriage so that its running direction essentially coincides with that of the guide rail. This is achieved by the third rollers acting as guide rollers, for example in curved sections, absorbing the centripetal forces acting laterally from the guide rail onto the running bodies, thereby deflecting the carriage. The third rollers also limit yaw movements, such as the maximum possible rotation of the carriage relative to the guide rail about a vertical axis (z). Consequently, the running direction of the carriage cannot deviate from that of the guide rail by more than a predetermined amount. This also prevents the first and second rollers, which act at least partly as support rollers, from coming into contact with parts of the guide rail that are not running surfaces. On the other hand, this also reduces the friction between the rollers and the running surfaces.The first and second rollers also serve to absorb yaw moments acting on the carriage.

[0060] The first and second rollers of the carriage serve to transfer the weight of the conveyed material and also that of the running body to the guide rail.

[0061] In addition, the first and second rollers also limit pitching movements of a carriage relative to the track, such as those that occur on sloping track sections. This is achieved by limiting pitching only to the extent that a front first or second roller comes into contact with an upper running surface of the track and a rear first or second roller comes into contact with a lower running surface. Pitching moments can thus be transferred to the track without a critical increase in rolling resistance. Likewise, such a limitation of pitching movements according to the invention prevents the first and second rollers from coming into contact with areas of the track that are not running surfaces.

[0062] Furthermore, the first and second rollers also limit rolling movements of the carriage relative to the guide rail, such as can occur in curved sections. In the case of pure rolling moments, a rolling movement is generated which leads to the first rollers coming into contact with the upper running surfaces and the second rollers with the lower running surfaces, or vice versa. Such contact defines a maximum rolling movement. This prevents the third rollers from coming into contact with parts of the guide rail that are not running surfaces. At the same time, the third rollers still guide the carriage and prevent the first and second rollers from coming into contact with areas of the guide rail that are not running surfaces.

[0063] The carriage body can, for example, be formed in one piece, which may potentially allow for cost-effective production. In principle, carriage bodies according to the invention can be manufactured using various processes and from different materials. For example, one-piece molding using injection molding is possible for plastics (e.g., polyethylene, polyurethanes, or polyamides) or metals (e.g., aluminum alloys or steel). Carriage bodies can also be made from long- or short-fiber-reinforced plastics, for example, glass fibers or carbon fibers.

[0064] The use of metallic or non-metallic inserts in a carriage body is also possible. These can be used, for example, to provide threads, attach support elements, or secure the support and guide rollers. Alternatively or in addition, inserts can also be used as local reinforcements in areas with concentrated load application and / or to stiffen the overall structure.

[0065] A carriage body can also be manufactured by bending sheet metal.

[0066] Particularly in the case of carriage bodies manufactured by bending sheet metal, other components can also be integrated into the carriage body. For example, coupling elements can be formed onto the carriage body by bending out sheet metal tabs or similar components. This type of functional integration can potentially significantly reduce manufacturing costs.

[0067] If necessary, corresponding bent sheet metal parts can also be overmolded with plastics or otherwise coated. Such designs may allow for the cost-effective production of carriage bodies with specific optical or chemical surfaces, such as those required for use in the food industry.

[0068] A carriage body can also be manufactured by machining, for example, from a preform. A carriage body can also be manufactured from a section of an extruded profile, such as a U-, V-, or Y-shaped profile. Several such sections can also be combined to form a carriage body.

[0069] The geometry of the carriage body can include additional elements that increase its strength and / or rigidity. For example, the legs and / or the connecting section can be shell-shaped. Alternatively or additionally, reinforcing ribs can be included, particularly in the area of the connecting section and the transitions from it to the two legs. Likewise, a carriage body can have areas with increased wall thickness.

[0070] The carriage advantageously has several coupling elements, which are arranged mirror-symmetrically to the vertical plane of symmetry. Other arrangements are also possible.

[0071] The carriage can also be equipped with an optional marker that allows the carriage and / or the transported goods attached to the carriage to be clearly identified. This marker can be an RFID tag or an optical marking such as a label or barcode. The use of multiple markers is also possible. Such markers can also be arranged in or on a coupling element.

[0072] The carriage body can advantageously also have at least one elastically deformable buffer body that projects outward in a running direction of the carriage. Such buffer bodies serve to dampen shocks when several carriages mounted on a guide rail collide. For this purpose, the buffer body can be made, for example, at least partially from an elastic or preferably elastic-plastic material. The buffer body can be an integral part of the carriage body or a separate component that is fixedly or detachably connected to it. For this purpose, it can have one or more pins with which it engages in a corresponding bore in the carriage body.

[0073] In the case of a carriage body produced by bending sheet metal, a buffer body can also be injection-molded, which can create a particularly simple and mechanically resilient connection between the carriage body and the buffer body if required.

[0074] Alternatively, or in addition, projections (e.g., sheet metal tongues) can be attached to the carriage body, which can be inserted into corresponding openings in the buffer bodies to mechanically connect the buffer bodies to the carriage body. If necessary, these projections can also be provided with barbs that prevent them from being separated once inserted.

[0075] The conveyor system according to the invention, in particular the gravity conveyor system, is particularly suitable for conveying goods with a mass between approximately 50 grams and 30 kilograms. However, with appropriate scaling, a conveyor system according to the invention can in principle also be used for goods with a mass outside this range. During operation of such a system, some of the carriages can be loaded with goods, while another part of the carriages remains empty and determines and maintains a distance between the carriages loaded with goods. In this way, even larger goods can be conveyed without the goods from different carriages coming into contact with each other. If necessary, the maximum load acting on a guide rail per unit length can also be limited in a simple and safe manner.

[0076] One or more leading empty carriages and / or one or more trailing empty carriages can also be coupled to a carriage loaded with a transported item in order to form a fixed carriage composition.

[0077] Likewise, a number of carriages can be connected or linked together to form a chain of carriages. This also allows for conveyance via a drive attached to the guide rail.

[0078] The resulting chain can be an endless chain (closed chain). However, the resulting chain can also be a finite chain with a first and a last carriage. Short explanations of the characters

[0079] The invention will be explained in more detail below using exemplary embodiments in conjunction with the accompanying drawings. They show schematically: Fig. 1 shows an embodiment of a carriage for a conveyor, in particular a gravity conveyor, in a perspective view from above; Fig. 2 shows the embodiment of Fig. 1 in a front view; Fig. 3 the embodiment of Fig. 1 in a view from above; Fig. 4 the embodiment of Fig. 1 in a side view; Fig. 5 an embodiment of a guide rail for the carriage made of Fig. 1 in profile view; Fig. 6the carriage from Fig. 1 in the guide rail Fig. 5 ; Fig. 7 in a side view a combination of three carriages according to Fig. 1 , where the middle carriage carries a transported item, while the other two carriages are unloaded and serve to maintain distance; Fig. 8 in a Fig. 7comparable illustration a combination of two loaded carriages, which are kept at a distance by two unloaded carriages and are additionally combined with one unloaded leading and trailing carriage each; Fig. 9 an embodiment of a carriage as a carrying carriage with a support plate in a perspective view from below; Fig. 10 the embodiment of Fig. 9 in a front view. Ways to implement the invention

[0080] The Figures 1 to 4 show in various views an embodiment of a carriage 1 for a conveyor, in particular a gravity conveyor. The carriage 1 shown comprises a carriage body 2 with a U-shaped cross-section, which in this embodiment has a (horizontal) connecting section 3 arranged at the bottom and laterally adjoining a first and second (vertical) leg 4 and 5, respectively. As a result, the carriage shown is capable of supporting a guide rail according to Fig. 5to encompass and travel on it as an external runner. On the inside of the first leg 4, in the embodiment shown, two first rollers 6a,b are arranged, which act as support rollers. On the inside of the second leg 5, two second rollers 7a,b are arranged, which also serve as support rollers. All first and second rollers are each rotated about a rotational axis 47 ( Fig. 2 ) rotatably mounted.

[0081] As in the Figures 2 and 3 As shown, the rotation axes 47 of the first and second roller pairs 6a,b, 7a,b are aligned substantially parallel to each other (parallel to the y-axis). Furthermore, the first rollers 6a,b and second rollers 7a,b are oriented with respect to a vertical plane of symmetry 45 (parallel to the xz-plane; Fig. 3 ) are arranged mirror-symmetrically to each other.

[0082] Two third rollers 8ab are arranged centrally on the inside of the connecting section 3 and are rotatably mounted. These third rollers act as guide rollers. The axes of rotation of the third rollers 8a,b lie in the plane of symmetry 45 (see Figure 3 ). In the illustrated embodiment of a carriage 1 according to the invention, the rotational axes 46 of the two third rollers 8a,b have the same distance from each other as the rotational axes 47 of the first and second rollers 6a,b, 7a,b. The guide rollers and the first and second rollers are also all of the same construction. As shown in the Figures 2 and 3 As shown, the rollers used also have slightly cambered running surfaces. Such cambering can reduce the rolling resistance of the rollers, especially when the carriage rotates around an axis parallel to the running direction (x).

[0083] The first and second rollers 6a, b, 7a, b are each designed as ball bearings overmolded with plastic. The roller axles, when assembled, are mounted in bores provided in the carriage body. In the illustrated embodiment, the axles are screwed with nuts 16. For this purpose, recesses 17 are provided on the outer sides of the first and second legs 4, 5, into which the nuts 16 can be countersunk. This prevents unwanted protrusions on the outer surfaces of the legs 4, 5.

[0084] On the (downwardly directed) outside of the connecting section 3, means for hanging transport goods can be attached, as will be shown later ( Fig. 7 , 8 ).

[0085] In the exemplary embodiment, coupling elements 9a,b are attached to the outer sides of the first and second legs 4, 5, which protrude laterally (y-axis) from the carriage (horizontally). These coupling elements 9a,b serve, for example, to couple the carriage 1 to a driver of a drive chain (not shown) for upward movement on an incline. As shown in Figure 3 As shown, the coupling elements 9a,b (e.g. with a press fit) can be fastened in through holes in the first or second leg 4, 5 and can also partially protrude inwards beyond their inner sides. As shown in the Figures 4 and 5 As shown, the coupling elements 9a,b in the illustrated embodiment of a carriage 1 are arranged centrally between the axes of rotation of the first and second roller pairs 6a,b, 7a,b. The center axis of the coupling elements 9a,b is also located at the same height (in the direction of the z-axis) as the axes of rotation 47 of the first and second rollers 6a,b, 7a,b.

[0086] The embodiment of the carriage 1 shown in the figures also has elastically deformable buffer bodies 11a-d mounted in the upper area of the legs 4, 5 (cf. Figure 1 ). These serve as damping elements, which, for example, dampen shocks when two independently moving carriages 1 collide. For this purpose, the buffer bodies 11a-d protrude from the carriage body 2 in the running direction (or opposite running direction, x-axis) and are made of an elastic or elastic-plastic material. In the embodiment shown, the buffer bodies 11a-d have pins 13, which engage in corresponding holes on the carriage body 2 and establish a connection therewith, as shown in Figure 4 is indicated. The buffer bodies 11a-d have a crown to prevent tilting of adjacent carriages.

[0087] In addition to these upper buffer bodies 11a-d, the carriage 1 shown also has lower buffer bodies 12a,b mounted centrally on the lower connecting section 3. These are offset from the upper buffer bodies 11a-d in the running direction (x-axis). The lower central buffer bodies 12a,b are arranged in recesses on the lower connecting section 3. These offset lower buffer bodies 12a,b are intended to dampen impacts between the lower connecting sections 3 of successive carriages 1 on tracks with decreasing gradients.

[0088] The Figure 5shows a possible guide rail 20 for a carriage 1 according to the invention. The guide rail 20 comprises first, second, and third profile sections 21, 22, 23, each having a U- or C-shape. These profile sections are arranged such that the overall profile of the guide rail 20 results in upper horizontal legs 24a,b and lower horizontal legs 25a-b. These legs 24a,b, 25a,b are each connected by vertical connecting sections 27a,b.

[0089] On the lower side of the guide rail 20, two vertical legs 26a,b are arranged, which are connected by a horizontal connecting section 27c. The inner sides of the horizontal legs 24a,b, 25a,b are each designed as horizontal running surfaces 28a-d for the support rollers.

[0090] The inner sides of the vertical legs 26a,b are each designed as vertical running surfaces 29a,b for the guide rollers.

[0091] Between the connecting sections 27a-c there is an intermediate space 30 extending in the longitudinal direction of the rail, which is closed on its upper side by a mechanical connection 31.

[0092] In the illustrated guide rail 20, fastening openings 32a,b are also arranged along the running direction (x-axis) in the horizontal connecting section 27c, as well as in the mechanical connection 31. For example, screws for suspending a guide rail 20 or for connecting several guide rails 20 using a corresponding connector can be installed in these openings.

[0093] In Figure 6shows how a carriage 1 according to the previously described embodiment acts as an external runner on a guide rail 20. The first support rollers 6a,b are arranged in the region of the first profile section 21 between the upper horizontal leg 24a and the lower horizontal leg 25a. The same applies analogously to the second support rollers 7a,b and the second profile section 22. The first and second support rollers 6a,b, 7a,b can each be in rolling contact either at the bottom with a lower horizontal running surface 28b, 28d or at the top with an upper horizontal running surface 28a, 28c. For this purpose, the vertical distance between the horizontal running surfaces is selected to be slightly larger than the maximum diameter of the support rollers.

[0094] The guide rollers 8a,b are arranged in the area of the third profile section 23 between the vertical legs and can each be in rolling contact with one of the two vertical running surfaces 29a or 29b. Here, too, the horizontal distance between the vertical running surfaces is selected to be slightly larger than the maximum diameter of the guide rollers.

[0095] Due to this arrangement of the rollers relative to the running surfaces, any displacement or rotation of the carriage 1 relative to the guide rail 20 that would lead to contact of the rollers with parts of the guide rail that are not running surfaces is eliminated. Likewise, direct contact of the carriage body 2 with the guide rail 20 is prevented.

[0096] As in Figure 7As shown, carriages can be used in a conveyor system according to the invention, in this case designed as a gravity overhead conveyor system, both as transport carriages 40 and as spacer carriages 41. Transport carriages 40 can pick up transport goods 43 by means of carrying means 42. As shown in Figure 7 shown, it is possible to have one or more spacer carriages 41 running in front of and / or behind a transport carriage 40. This can be done, as shown in Figure 7 shown, in a loose connection, in which the transport carriage 40 and the spacer carriages 41 only temporarily touch each other via the buffer bodies 11, but otherwise move largely independently of each other along the guide rail 20.

[0097] Alternatively, transport carriage 40 and spacer carriage 41 can also be connected to form a permanent assembly via detachable coupling means 44, as shown in Figure 8These coupling means 44 can be integrated into the buffer bodies 11, as shown. Such permanent connections between multiple carriages 1 ensure that they remain together even at branching points, or reduce the number of switch positions. Likewise, if necessary, the material to be transported can be distributed among several carriers of a drive chain on uphill sections.

[0098] The Figures 9 and 10 show an embodiment of a carriage 1 which is not designed for suspended conveying but for supporting or carrying conveying. For this purpose, the carriage 1 is, in comparison to the Figures 1 to 8 The carriage shown is rotated 180° around the x-axis. A plate 48 is mounted on the connecting section 3, which is located at the top in this embodiment, and can serve as a support for transported goods (not shown).

[0099] The plate 48 can have a gradation in the z-direction as shown.

[0100] By linking several such carriages 1 with plates 48 (not shown), a carriage arrangement can be formed with a plate arrangement formed from the plates 48 and extending in the running direction. The plates 48 arranged on the individual carriages 1 overlap in such an arrangement similar to fish scales. This allows the formation of a larger plate arrangement extending in the running direction. Interlinked plate conveyors can also be formed in this way.

Claims

1. Carriage (1) for a rail-guided conveyor system, in particular a gravity-type conveyor, comprising a. a carriage body (2) which is configured for embracing a running rail (20) and which comprises a first and a second leg (4, 5) which are interconnected by a transversely extending connection portion (3), wherein b. the first leg (4) has first rollers (6a,b) which are attached to the internal side of the former, and the second leg (5) has second rollers (7a,b) which are attached to the internal side of the former, wherein the first and the second rollers (6a,b; 7a,b) are vertically disposed and each are provided in pairs and wherein the first and the second rollers (6a,b; 7a,b) are disposed in a mirror-symmetrical manner to a vertical symmetry plane (45) of the carriage (1), and wherein c. at the connection portion (3) means for conveying objects in a suspended manner are attached, characterized in that the connection portion (3) has third rollers (8a,b) which are attached to the internal side of the former, the third rollers (8a,b) are provided in pairs and wherein the rollers of each pair are disposed sequentially in the running direction of the carriage (1), wherein the rotation axes (46) of the third rollers (8a,b) lie in the vertical symmetry plane (45) of the carriage (1) and the third rollers (8a,b) are horizontally disposed.

2. Carriage according to Claim 1, characterized in that means (42) for conveying objects (43) in a suspended or supported manner are attached to the connection portion (3).

3. Carriage according to one of Claims 1 or 2, characterized in that the third rollers (8a,b) and the first and the second rollers (6a,b; 7a,b) have the same dimensions.

4. Carriage according to one of Claims 1 to 3, characterized in that the first and the second rollers (6a,b; 7a,b) and / or the third rollers (8a,b) are each configured to comprise a roller body being injection-moulded around a ball bearing.

5. Carriage according to one of Claims 1 to 4, characterized in that the first and the second rollers (6a,b; 7a,b) and the third rollers (8a,b) are releasably fastened to the carriage body (2), in particular are screwed to the carriage body (2).

6. Carriage according to one of Claims 1 to 5, characterized in that the carriage body (2) is integrally configured.

7. Carriage according to one of Claims 1 to 6, characterized in that the carriage (1) has at least one coupling element (9 a,b) for the at least temporary coupling to a device for accelerating or for uniformly moving or for braking the carriage, said coupling element (9 a,b) being disposed so as to outwardly protrude on the first or the second leg (4, 5) or on the connection portion (3).

8. Carriage according to Claim 7, characterized in that the carriage (1) has two coupling elements (9 a,b) which are disposed in a mirror-symmetrical manner to the vertical symmetry plane (45).

9. Carriage according to one of Claims 1 to 8, characterized in that the carriage (1) has at least one elastically deformable buffer body (11 a-d; 12 a,b) for buffering any contact with a second carriage, said buffer body (11 a-d; 12 a,b) outwardly protruding from the carriage body (2) in a running direction of the carriage (1).

10. Carriage according to Claim 9, characterized in that the carriage (1) has at least one central buffer body (12 a,b) which is centrally attached to the connection portion (3).

11. Carriage according to one of Claims 1 to 10, characterized inthat the carriage (1) has coupling means (44) by way of which the former may be connected to at least one other carriage so as to form a linked carriage assembly.

12. Carriage according to Claim 11, characterized in that the carriage (1) has at least one elastically deformable buffer body (11 a-d; 12 a,b) for buffering any contact with a second carriage, said buffer body (11 a-d; 12 a,b) outwardly protruding from the carriage body (2) in a running direction of the carriage (1), and in that the coupling means (44) are integrated in the buffer body.

13. Conveyor system comprising at least one running rail (20) and at least one carriage (1) according to one of Claims 1 to 12, wherein the running rail (20) and the carriage (1) are mutually adapted and the running rail (20) is embraced by the carriage (1).

14. Conveyor system according to Claim 13, characterized in that a plurality of carriages (1) are provided, in that some of the carriages (1) are configured as transportation trucks (40) and are loadable with cargo (43), and some of the carriages (1) are configured as spacer trucks (41) and are employable for ensuring a spacing between the transportation trucks (40).

15. Method for operating a conveyor system according to Claim 13, wherein a plurality of carriages (1) are provided, and some of the carriages (1) are loaded with cargo (43), and some of the carriages (1) are empty and are employed for configuring a spacing between those carriages that are loaded with cargo (43).

16. Method according to Claim 15, characterized in that the carriages (1) that are loaded with cargo (43), and the empty carriages (1) that are employed for configuring a spacing between the former are coupled to one another.

17. Method according to one of Claims 13 to 16, characterized in that a plurality of carriages (1) are linked to form at least one coupled carriage assembly.

18. Method according to Claim 17, characterized in that the load of at least one conveyed item of cargo (43) is distributed across a plurality of carriages (1) of the at least one coupled carriage assembly.