A conveyor device

Abstract

A conveyor device (120) comprising an endless track; a plurality of carriers (126) distributed in along said track; driving means for moving said plurality of carriers (126) along said track; wherein each carrier (126) comprises at least one support surface for carrying one or more objects; wherein each carrier (126) is supported and guided by means of one or more brackets (143, 276) comprising at least three rollers (239, 240, 241) engaging said at least one guide rail (138, 156); and wherein a first roller (239) of said at least three rollers engages the at least one guide rail (138) in a direction perpendicular to said transport direction X and said transverse direction, and the other two rollers (240, 241) of said at least three rollers engage the at least one guide rail (138) in respective different directions which are not perpendicular to the transverse direction, such that movement of the carrier (126) in said transverse direction is prevented;wherein at least one roller (241) of said at least other two rollers (240, 241) is mounted on a shaft (341); and wherein said shaft (341) is movably mounted in one of said one or more brackets (143, 276) in such a manner that said shaft (341) is allowed to move towards and away from the at least one guide rail (138, 156), and said shaft (341) is biased towards said at least one guide rail (138, 156) by resilient means.;

Description

Field The present invention relates to comprising: an endless track which follows a track path in a transport direction wherein said track is formed by a base frame carrying at least one guide rail; a plurality of carriers distributed along said track, driving means for moving said plurality of carriers along said track; wherein each carrier comprises at least one support surface for carrying one or more objects, said support surface extending in the transport direction and a transverse direction; wherein each carrier is supported and guided by means of one or more brackets comprising at least three rollers engaging said at least one guide rail; wherein a first roller of said at least three rollers engages the at least one guide rail in a direction perpendicular to said transport direction and said transverse direction, and the other two rollers of said at least three rollers engage the at least one guide rail in respective different directions which are not perpendicular to the transverse direction, such that movement of the carrier in said transverse direction is prevented; and wherein at least one roller of said at least other two rollers is mounted on a shaft. Background Such a device is disclosed in US 6,907,985 B1. There is a continuous desire to increase the capacity of conveyor devices, in particular sorter devices for sorting and distributing objects, such as parcels. One way to increase the capacity is to increase the speed at which the carriers are moved along the track. An increase in speed, however, also increases the noise level of the conveyor device, and it may also lead to increased wear of the device. The invention aims at an improved conveyor device, which addresses these concerns at least in part. Summary To this end, said shaft is movably mounted in one of said one or more brackets in such a manner that said shaft is allowed to move towards and away from the at least one guide rail, and said shaft is biased towards said at least one guide rail by resilient means. Thereby the noise and wear of the device may be decreased, because, in particular in the curves of the track and at high transport speeds, in the lateral direction the wheels are allowed to support against the rail continuously without too much friction. According to an embodiment, said at least one guide rail comprises a first guide rail and a second guide rail, wherein said first guide rail and said second guide rail extend parallel to each other in a transverse direction, and said one or more brackets comprises at least a first roller engaging said second guide rail. According to an embodiment, said three rollers engage said first guide rail. According to an embodiment, said at least first roller engaging said second guide rail is said at least one roller of said at least other two rollers which is mounted on the shaft which is movably mounted in one of said one or more brackets. According to an embodiment, said at least one guide rail is a monorail which is engaged by all the rollers that support the carrier. According to an embodiment, said one or more brackets comprises at least one first bracket with a first set comprising said three rollers. According to an embodiment, said one or more brackets comprises a second bracket comprising said at least first roller engaging said second guide rail. According to an embodiment, said at least first roller engaging said second guide rail comprises: said at least one roller which is movably mounted in said second bracket, and one other roller which engages said second guide rail in a direction perpendicular to said transport direction and said transverse direction. Preferably, said first roller of said at least three rollers and / or said first roller engaging the second guide rail engage(s) the guide rail at the top side of said guide rail. Preferably, the second bracket comprises a further roller, opposite the first roller such that the rollers receive the second guide rail between each other. According to a preferred embodiment, the shaft is connected at one end of said shaft to the first bracket by means of a hinge shaft such that the roller is allowed to swivel around said hinge shaft towards and away from the at least one guide rail. According to an especially preferred embodiment, said resilient means comprises a spring, preferably a torsion spring. According to various embodiments, said at least one guide rail has a circular crosssection, a rectangular crosssection, a square crosssection, a Ushaped crosssection, or is a profiled beam. According to an embodiment, the conveyor device is a sorter device. According to an embodiment, said support surfaces are formed by top surfaces of respective crossbelt conveyors. According to an especially preferred embodiment, said at least one first bracket is pivotable relative to said carrier around a swivel axis which is perpendicular to said transport direction and said transverse direction, and said first roller is attached to said first bracket in such a manner that the rotation axis of said first roller is located at a distance from said swivel axis, seen in the transverse direction. Thereby a caster wheel type construction is formed whereby the noise and wear of the device may be decreased, in particular in the curves of the track and at high transport speeds, as the bracket with the three rollers are allowed to align with the rail. Preferably, the rotation axis of the first roller is located behind the swivel axis in the transport direction. Preferably, the distance between the rotation axis first roller and the swivel axis is at least 25%, preferably at least 50% of the diameter of the first roller. According to an especially preferred embodiment, said at least one second bracket is pivotable relative to said carrier around a swivel axis which is perpendicular to said transport direction and said transverse direction, and said first roller is attached to said second bracket in such a manner that the rotation axis of said first roller is located at a distance from said swivel axis, seen in the transverse direction. Preferably, the rotation axis and rotation axis of the respective mentioned other two rollers are positioned such that the swivel axis substantially intersects the rotation axes. According to an embodiment, said at least one first bracket and / or said second bracket are substantially Cshaped, seen in the transport direction, and extend partially around the respective guide rail. According to an embodiment, said at least one first bracket and / or said second bracket extend partially around the lateral outer side of the respective guide rail. Brief Description of Drawings The present invention will now be illustrated with reference to the drawings, wherein: Figure 1 shows a perspective view of a part of ; Figures 2A and 2B respectively show a partial perspective view and crosssection of part of ; Figures 3A and 3B respectively show a perspective view and crosssection of a first bracket with rollers of the conveyor device; Figure 4 schematically shows a rail with the engagements of the rollers; and Figures 5A 5F show schematic cross sections of various embodiments of . Detailed description With reference to figure 1, 120 for conveying and sorting objects, has a track that forms a closed loop. The conveying and sorting track comprises straight sections as well as left and right curved sections (not shown). Not only horizontal conveying and sorting tracks can be formed, but also vertically ascending or descending sections, and even sections that intersect one another. Thereby it is possible to form conveying and sorting tracks that can be arranged in any desired way in the threedimensional space. The device 120 comprises a left hand first guide rail 138 and a right hand second guide rail 156, seen in the transport direction X. The first guide rail 138 and the second guide rail 156 extend parallel to each other and are each formed as a tube, which has a circular crossfsection. Both the first guide rail 138 and the second guide rail 156 are secured in a base frame 149, comprising spaced apart upright poles 150 which are secured to the floor, a tube 151 which runs parallel to and centrally located under the guide rails 138, 156, and which is connected thereto by means of plate shaped, spaced apart connectors 152. The device 120 comprises a multitude of carriers 126 which are guided along the conveying track. The carriers 126 may be interconnected by means of a hinged coupling so as to pull each other forward, or they may push each other forward. Driving means are provided to move the carriers 126 along the track at one or more locations, which driving means may be in the form of a linear motor. These driving means are not shown in the figures. Sorting units 121 are secured on the traveling carriers 126 and each sorting unit comprises a multitude of crossbelts 177 that can be driven in a transverse direction in relation to transport direction X. Crossbelts 177 are guided in each case via a set of reversing rollers, with axles of rotation that extends in transport direction. The transverse drive of the crossbelts 177 of sorting units 121 occurs by using driving means that can be selectively caused to operate. These driving means are not shown in the figures. Referring to figures 2AB and 3AB, carriers 126 each comprise two first brackets 143 that are spaced apart from each other in the transport direction X. These first brackets 143 are substantially Cshaped, seen in the transport direction X, and extend around the guide rail 138 and each comprise three running rollers 239, 240 and 241. Running rollers 239, 240 and 241 thereby extend around the guide rail 138, seen in the transport direction X (see figure 2B). Thus, seen in the transport direction X, running rollers 239, 240 and 241, or their respective axles of rotation, are arranged at an angle of about 120 degrees around the longitudinal axis of the guide rail 138, so that guide rail 138 is engaged by rollers 239, 240 and 241 in a formlocked manner. One roller 239 engages the guide rail 138 at the top side of the guide rail in the centre, whereas the other two rollers 240, 241 engage the guide rail 138 on lateral sides at the bottom side of the guide rail 138. Furthermore, the carriers 126 each comprise at least one second bracket 276 which comprise two oppositely arranged running rollers 272 and 273 which are mounted in the bracket 276 by means of rotational shafts which extend in parallel, whereby rollers 272 and 273 receive the second guide rail 156 between each other and are guided on this second guide rail 156. One roller 272 engages the second guide rail 156 at the top side of the guide rail 156 in the centre, whereas the other roller 273 is located at the bottom side of the guide rail 156 in the centre. In order to prevent unnecessary friction and wear, the second roller 273 does not normally touch the rail (in other words, there is a small gap between the roller 273 and the rail 156), its function is merely to prevent that the carrier 126 tilts away from the rail 156. The rollers 239, 240, 241, 272, 273 may be provided with a rubber circumference or rubber tyre for engaging the guide rails 138, 156. The first brackets 143 are rotatably mounted on the carrier 126, such that the first brackets 143 are allowed to swivel around a vertical axis 278 which is perpendicular to both the transport direction X and the transverse direction. Seen from above, in the vertical direction of the axis 278 (see figure 3B), the rotation axis 250 and rotation axis 251 of the respective rollers 240, 241 which engage the lateral sides at the bottom side of the guide rail 138 are positioned such that the vertical axis 278 intersects these rotation axes 250, 251. The swivel axis 278 also intersects the guide rail 138. Preferably the swivel axis 278 intersects the central axis of guide rail 138, seen in vertical direction. The first bracket 143 comprises a bracket arm 244 which extends from the top side of the first bracket 143 from the axis 278 in the rearward transport direction. The roller 239, which engages the guide rail 138 at the top side of the guide rail in the centre, is rotatably mounted in said bracket arm 244, such that its rotation axis 249 in the transport direction X is located behind the vertical axis 278. Thereby the first bracket 143 is allowed to swivel around the vertical axis 278, with the roller 239 acting as a caster wheel to maintain the bracket 143 with the two other rollers 240, 241 oriented in the transport direction X, thereby reducing friction and vibration, especially in curved sections of the track. Likewise, also the second bracket 276 is rotatably mounted on the carrier 126, such that the second bracket 276 is allowed to swivel around a vertical axis which is perpendicular to both the transport direction X and the transverse direction, and the second bracket 276 comprises a similar bracket arm which extends from the top side of the second bracket from the axis in the rearward transport direction. The roller 272, which engages the guide rail 156 at the top side of the guide rail in the centre, is rotatably mounted in said bracket arm, such that its rotation axis in the transport direction X is located behind the vertical axis. Thereby also the second bracket 276 is allowed to swivel around the vertical axis, with the roller 272 acting as a caster wheel to maintain the bracket 276 with the other roller 273 oriented in the transport direction X, thereby reducing friction and vibration, especially in curved sections of the track. Referring to figures 3A, 3B and 4, one of the rollers, in this embodiment roller 241 which engages the laterally outer side of the guide rail 138 at the bottom side, is resiliently mounted in the first bracket 143, such that the roller 241 is biased against the guide rail 138. The roller 241 is mounted on a shaft 341 which is movably mounted in the first bracket 143 so that is allowed to move towards and away from the first guide rail 138. The shaft is biased against the first guide rail 138 by resilient means. In this embodiment the shaft 341 on which the roller 241 is rotatably mounted around its axis 251 is connected at one end of said shaft 341 to the first bracket 143 by means of a hinge shaft 342. Thereby roller 241 is allowed to swivel around said hinge shaft 342 towards and away from the first guide rail 138. A torsion spring 343 is mounted around said hinge shaft 342, with one end of the torsion spring 343 connected to the first bracket 143 and the other end of the torsion spring 343 connected to the shaft 341, such that the torsion spring 343 pushes the roller 241 against the guide rail 138 (see figure 4). According to the embodiment as shown in figure 5A, the track comprises a first guide rail 138 and a second guide rail 156, which extend parallel to each other in transverse horizontal direction. The guide rails 138, 156 are tubular, with a circular crosssection. The carrier 126 comprises two brackets 143, 276. The first bracket 143 comprises three rollers 239, 240, 241 engaging the first guide rail 138. The first roller 239 engages the guide rail 138 in the vertical direction at the top side. The other two rollers 240, 241 engage the guide rail 138 in respective oblique upward directions, such that movement of the carrier 126 in the transverse direction and upward direction is prevented. The second bracket 276 comprises a first roller 272 engaging the second guide rail 156 at the top side. The second bracket further comprises a further roller 273, opposite the first roller 272 such that the rollers 272, 273 receive the second guide rail 156 between each other, in order to prevent upward movement of the second bracket. There is a gap between the further roller 273 and the rail 156, such that there is normally no contact with the rail 156. The roller 241 is mounted on a shaft 341, which is movably mounted in the bracket 143 in such a manner that the shaft 341 is allowed to move towards and away from the rail 138, while the shaft 341 is biased towards the rail 138 by the resilient means 243. According to the embodiment as shown in figure 5B, the track comprises a first guide rail 138 and a second guide rail 156, which extend parallel to each other in transverse horizontal direction. The guide rails 138, 156 are tubular, with a circular crosssection. The carrier 126 comprises two brackets 143, 276. The first bracket 143 comprises two rollers 239, 240 engaging the first guide rail 138. The first roller 239 engages the guide rail 138 in the vertical direction at the top side. The other roller 240 engages the guide rail 138 in an oblique upward direction, such that movement of the carrier 126 in the transverse direction and upward direction is prevented. The first bracket further comprises a further roller 273, opposite the first roller 272 and the other roller 240, directed in an oblique upward direction towards the guide rail 138, such that movement of the carrier 126 in the transverse and upward direction is further prevented. There is a gap between the further roller 273, such that there is normally no contact with the rail 156. The second bracket 276 comprises a first roller 272 engaging the second guide rail 156 at the top side. The roller 241 is also mounted on the second bracket, engaging the second guide rail from the lateral side opposite the roller 240 engaging the first rail 138. The second bracket further comprises a further roller 273, opposite the first roller 272, such that the rollers 272, 273 receive the second guide rail 156 between each other, in order to prevent upward movement of the second bracket. There is a gap between the further roller 273 and the rail 156, such that there is normally no contact with the rail 156. The roller 241 is mounted on a shaft 341, which is movably mounted in the bracket 276 in such a manner that the shaft 341 is allowed to move towards and away from the rail 138, while the shaft 341 is biased towards the rail 138 by the resilient means 243. According to the embodiment as shown in figure 5C, the track comprises a first guide rail 138 and a second guide rail 156, which extend parallel to each other in transverse horizontal direction. The guide rails 138, 156 are profiled beams, of which the part that is engaged by the rollers has a substantially Cshape. The carrier 126 comprises two brackets 143, 276. The first bracket 143 comprises three rollers 239, 240, 241 engaging the first guide rail 138. The first roller 239 engages the guide rail 138 in the vertical direction on the inside of the Cshaped profile. The upper part of the Cshaped profile prevents movement of the first bracket 143 in the vertical direction. There is a gap between the first roller 239 and the upper part of the Cishaped profile, such that there is normally no contact with the rail 138. The other two rollers 240, 241 engage the upright part of the Cshaped profile of the guide rail 138 in respective opposite lateral directions, such that movement of the carrier 126 in the transverse direction is prevented. The second bracket 276 comprises a first roller 272 engages the guide rail 156 in the vertical direction on the inside of the Cshaped profile. The upper part of the Cshaped profile prevents movement of the second bracket 276 in the vertical direction. There is a gap between the first roller 272 and the upper part of the Cshaped profile, such that there is normally no contact with the rail 156. The roller 241 is mounted on a shaft 341, which is movably mounted in the bracket 143 in such a manner that the shaft 341 is allowed to move towards and away from the rail 138, while the shaft 341 is biased towards the rail 138 by the resilient means 243. According to the embodiment as shown in figure 5D, the track comprises a first guide rail 138 and a second guide rail 156, which extend parallel to each other in transverse horizontal direction. The guide rails 138, 156 are profiled beams, of which the part that is engaged by the rollers has a substantially Cshape. The carrier 126 comprises two brackets 143, 276. The first bracket 143 comprises two rollers 239, 240 engaging the first guide rail 138. The first roller 239 engages the guide rail 138 in the vertical direction on the inside of the Cshaped profile. The upper part of the Cshaped profile prevents movement of the first bracket 143 in the vertical direction. There is a gap between the first roller 239 and the upper part of the Cshaped profile, such that there is normally no contact with the rail 138. The other roller 240 engages the inner side of the upright part of the Cshaped profile of the guide rail 138, such that movement of the carrier 126 in the transverse direction is prevented. The second bracket 276 comprises a first roller 272 engages the guide rail 156 in the vertical direction on the inside of the Cshaped profile. The upper part of the Cshaped profile prevents movement of the second bracket 276 in the vertical direction. There is a gap between the first roller 272 and the upper part of the Cshaped profile, such that there is normally no contact with the rail 156. The roller 241 is also mounted on the second bracket, engaging the inner side of the upright part of the Cshaped profile of the guide rail 138, such that movement of the carrier 126 in the transverse direction is prevented. The roller 241 is mounted on a shaft 341, which is movably mounted in the bracket 276 in such a manner that the shaft 341 is allowed to move towards and away from the rail 156, while the shaft 341 is biased towards the rail 156 by the resilient means 243. According to the embodiment as shown in figure 5E, the track is a monorail, comprising a single guide rail 138. The guide rail 138 is tubular, with a square or rectangular crosssection. The carrier 126 comprises a bracket 143, which in this schematic drawing is represented by three different parts. The bracket 143 comprises three rollers 239, 240, 241 engaging the guide rail 138. The first roller 239 engages the guide rail 138 in the vertical direction at the top side. The other two rollers 240, 241 engage the guide rail 138 in respective laterally opposite directions, such that movement of the carrier 126 in the transverse direction is prevented. The bracket 143 further comprises a further roller 273, opposite the first roller 239 such that the rollers 239, 273 receive the guide rail 138 between each other, in order to prevent upward movement of the bracket. There is a gap between the further roller 273 and the rail 138, such that there is normally no contact with the rail 138. The roller 241 is mounted on a shaft 341, which is movably mounted in the bracket 143 in such a manner that the shaft 341 is allowed to move towards and away from the rail 138, while the shaft 341 is biased towards the rail 138 by the resilient means 243. According to the embodiment as shown in figure 5F, the track is a monorail, comprising a single guide rail 138. The guide rail 138 is tubular, with a substantially Ushaped crosssection. The carrier 126 comprises a bracket 143, which in this schematic drawing is represented by two different parts. The bracket 143 comprises three rollers 239, 240, 241 engaging the guide rail 138. The first roller 239 engages the guide rail 138 in the vertical direction at the top side of the bottom wall of the Ushaped crosssection. The other two rollers 240, 241 engage the guide rail 138 in respective laterally opposite directions at one upright side wall of the Ushaped crosssection, such that movement of the carrier 126 in the transverse direction is prevented. The bracket 143 further comprises a further roller 273, opposite the first roller 239 on the bottom side of the Ushaped crosssection, such that the rollers 239, 273 receive the guide rail 138 between each other, in order to prevent upward movement of the bracket. There is a gap between the further roller 273 and the rail 138, such that there is normally no contact with the rail 138. The roller 241 is mounted on a shaft 341, which is movably mounted in the bracket 143 in such a manner that the shaft 341 is allowed to move towards and away from the rail 138, while the shaft 341 is biased towards the rail 138 by the resilient means 243. The invention has thus been described by means of preferred embodiments. It is to be understood, however, that this disclosure is merely illustrative. Various details of the structure and function were presented, but changes made therein, to the full extent extended by the general meaning of the terms in which the appended claims are expressed, are understood to be within the principle of the present invention. The description and drawings shall be used to interpret the claims. The claims should not be interpreted as meaning that the extent of the protection sought is to be understood as that defined by the strict, literal meaning of the wording used in the claims, the description and drawings being employed only for the purpose of resolving an ambiguity found in the claims. For the purpose of determining the extent of protection sought by the claims, due account shall be taken of any element which is equivalent to an element specified therein. An element is to be considered equivalent to an element specified in the claims at least if said element performs 5 substantially the same function in substantially the same way to yield substantially the same result as the element specified in the claims.

Claims

1. Transport equipment (120) comprising: an endless track that follows a track path in a transport direction where the track is formed by a base frame (149) that has at least one guide rail (138, 156) wears; a multitude of carriers (126) distributed along the track, means of propulsion for moving the multitude of carriers (126) along the track; where each support (126) includes at least one support surface for supporting of one or more objects, where the support surface extends into the transport direction and a transverse direction; where each carrier (126) is supported and guided by means of a or more brackets (143, 276) comprising at least three rollers (239, 240, 241) that engage on at least one guide rail (138, 156); where a first role (239) of the at least three roles acts on the ten at least one guide rail (138) in a direction perpendicular to the direction of transport and the transverse direction, and the other two rolls (240, 241) of the at least three rolls engage on at least one guide rail (138) in respective different directions that are not perpendicular to the transverse direction, such that movement of the carrier (126) is prevented in the transverse direction; and where at least one role (241) of the at least the other two roles (240, 241) is mounted on a shaft (341); where the shaft (341) is movably mounted in one of the one or more brackets (143, 276) in such a way that the axle (341) is allowed to move to and away from to move at least one guide rail (138, 156), and the shaft (341) by means of a resilient means to at least one guide rail (138, 156) is pre-stressed.

2. Transport arrangement according to claim 1, where at least one guide rail (138, 156) a first guide rail ( 138) and includes a second guide rail (156), where the first guide rail (138) and the second guide rail (156) are extend parallel to each other in a transverse direction, and where one or more brackets (143, 276) at least a first roll (241, 272) include which engages with the second guide rail (156).

3. Transport arrangement according to claim 2, where the three rollers (239, 240, 241) engage the first guide rail (138).

4. Transport arrangement according to claim 2, where at least the first roller (241) engages with the second guide rail (156) the at least one role (241) is of the at least other two roles (240, 241) that is mounted on the shaft (341) which is movably mounted in one of the one or more braces (143, 276).

5. Transport arrangement in accordance with one of the preceding claims, where at least one guide rail (138) is a monorail that is attached is by all the rollers (239, 240, 241) that support the carrier (126).

6. Transport arrangement in accordance with one of the preceding claims, where one or more brackets include at least one first bracket (143) with a first set comprising the three roles (23 9, 240, 241).

7. Transport arrangement in accordance with claim 2, where one or more brackets include a second bracket (276) that the ten The smallest first roller (241, 272) includes the one that engages with the second guide rail (156).

8. Transport arrangement in accordance with claim 7, where the at least first role (241, 272) that relates to the second guide rail (156) includes the following: at least one roller (241) which is movably mounted in the second bracket (276), and another roller (272) that engages with the second guide rail (156) in a direction perpendicular to the direction of transport and the transverse direction.

9. Transport arrangement in accordance with one of the preceding claims, whereby the first role (239) of the at least three roles and / or the first role (272) which the second engages guide rail (156), engages on the guide rail (138, 156) at the top side of the guide rail (138, 156).

10. Transport arrangement in accordance with one of the preceding claims, whereby the second bracket (276) includes a further roll (273), opposite the first roll (272) such that the rollers (272, 273) support the second guide rail (156) mutually.

11. Transport arrangement in accordance with one of the preceding claims, where the axle (341) is connected to one end of the shaft (341) with the first bracket (143) by by means of a hinge axis (342) such that the roller (241) is allowed to move around the pivot axis (342) to turn towards and away from at least one guide rail (138).

12. Transport arrangement in accordance with one of the preceding claims, whereby the resilient medium (243) contains a spring, preferably a torsion spring (343).

13. Transport arrangement in accordance with one of the preceding claims, whereby the ten at least a guide rail a circular cross-section, a rectangular cross-section, a square cross-section, has a U-shaped cross-section, or is a profiled beam.

14. Transport arrangement in accordance with one of the preceding claims, whereby the transport device (120) is a sorting device (120).

15. Transport arrangement in accordance with one of the preceding claims, whereby the support surfaces are formed by top surfaces of respective cross belt conveyors ( 1 77). 1 / 5

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