A conveyor device

Abstract

A conveyor device (101) comprising: an endless track which follows a track path in a transport direction; a plurality of carriers (111) distributed in a closed loop along said track, wherein each carrier (111) comprises at least one rectangular support surface (103) for carrying one or more objects; wherein each support surface (103) is provided with upright side walls (128) extending along two opposite sides of said support surface (103) in upward direction up to a wall height, said sides of said support surface extending perpendicular to said transport direction; driving means for moving said plurality of carriers (111) along said track; wherein at least one of said side walls (128) is movable between an upper position and a lower position, wherein in the upper position the side wall (128) extends up to said wall height in said upward direction from said edge of the support surface, and in said lower position an object, which is supported by said support surface (103), is allowed to extend over the respective edge of said support surface (103) in a substantially flush manner towards the respective adjacent support surface (103) to be supported thereby.

Description

[0001]A conveyor device The present invention relates to a conveyor device comprising: an endless track which follows a track path in a transport direction; a plurality of carriers distributed in a closed loop along said track, wherein each carrier comprises at least one rectangular support surface for carrying one or more objects; wherein each support surface is delimited by upright side walls extending along two opposite sides of said support surface in upward direction up to a wall height, said sides of said support surface extending perpendicular to said transport direction; driving means for moving said plurality of carriers along said track. Such a device is disclosed in WO 2020 / 169435 A1. Other examples are of such conveyor devices are disclosed in US 5,547,084 A and WO 2001 / 024947 A2. The support surfaces disclosed in these documents are formed by the top surfaces of cross-belt conveyors, but the current invention is not limited thereto. The support surfaces may for instance be formed by the surface of trays provided with object pushers, such as disclosed in EP 1972579 A1. The upright side walls that extend next to the support surfaces provide a safeguard so objects that are placed onto the support surface and transported thereon at high speed don't slide off the support surface. At the same time the walls may prevent a more flexible use and / or a higher capacity use of the conveyor device. The invention aims at addressing this problem. To this end, a conveyor device according to the preamble is characterized in that at least one of said side walls is movable between an upper position and a lower position, wherein in the upper position the side wall extends up to said wall height in said upward direction from said edge of the support surface, and in said lower position an object, which is supported by said support surface, is allowed to extend over the respective edge of said support surface in a substantially flush manner towards the respective adjacent support surface to be supported thereby. An object which has a dimension in the transport direction which is larger than the distance between the two side walls may thus be carried by two joint adjacent support surfaces. Also for smaller objects, more efficient use may be made of the conveyor device if objects need to be placed on the location of a side wall for any other reason. According to a preferred embodiment, said side walls are held in the upper position by means of a holding force between the wall and the carrier, which force is chosen to have a value such that an object with a predetermined weight acting on the wall will force the wall to move to the lower position against said holding force. According to a favourable embodiment, said conveyor device is provided with at least one actuator which is arranged to move side walls from the lower position to the upper position. According to an alternative preferred embodiment, said holding force is a spring force between the wall and the carrier, which spring force is chosen to have a value such that an object with a predetermined weight acting on the top of the wall will force the wall to move to the lower position. According to an alternative preferred embodiment, said side walls are held in the upper position by means of the holding force of an actuator positioned between the wall and the carrier, which actuator is arranged to be operated in order to allow the wall to move to the lower position. According to a favourable embodiment, said actuator comprises a solenoid. According to a favourable embodiment, said actuator is connected to one or more sensors, which are arranged to sense an object being moved onto the side wall. According to a favourable embodiment, said actuator is connected to a control unit of the conveyor device, which control unit operates the switch based on timing information about an object being moved onto the side wall. According to a preferred embodiment, each carrier comprises at least two of said support surfaces, wherein each support surface is delimited by upright side walls extending along two opposite sides of said support surface in upward direction up to a wall height, said sides of said support surface extending perpendicular to said transport direction, wherein at least a side wall which extends between said support surfaces is movable between an upper position and a lower position. According to a preferred embodiment, all the side walls are movable between an upper position and a lower position. According to a preferred embodiment, said support surfaces are formed by top surfaces of respective cross-belt conveyors. According to a preferred embodiment, the track path comprises at least one straight section and multiple curved sections in horizontal direction. The track path may thus be part of called horizontal sorter. The invention may also apply to a track path which comprises straight sections and curved sections in the vertical direction, such as in a vertical sorter. According to a preferred embodiment, the conveyor device is a sorter device. The present invention will now be illustrated with reference to the drawing where Fig. 1A is a perspective top view of a part of a conveyor device; Fig. 1B is a perspective bottom view of a part of the conveyor device of Fig 1A; Fig. 2A is a perspective view of carriers of the conveyor device having side walls in an upper position; Fig. 2B is a perspective view of carriers of the conveyor device having side walls in a lower position; Fig. 3A is a front view of a first embodiment of a carrier having side walls in an upper position; Fig. 3B is a front view of the first embodiment of a carrier having side walls in a lower position; Fig. 4A is a front view of a second embodiment of a carrier having side walls in an upper position; Fig. 4B is a front view of the second embodiment of a carrier having side walls in a lower position; Fig. 5A is a front view of a third embodiment of a carrier having side walls in an upper position; Fig. 5B is a front view of the third embodiment of a carrier having side walls in a lower position; Fig. 5C is a perspective view of a side wall of the third embodiment; Fig. 5D is a side view of a part of the third embodiment of the conveyor device having some side walls in a lower position; and Fig. 5E is a side view of a part of the third embodiment of the conveyor device wherein some side walls are reset from the lower position to the upper position. With reference to Figs. 1 A / B, a cross-belt sorter of the type as disclosed in US 6,253,901 B1, the disclosure of which is incorporated herein by reference, comprises a conveyor device 101. The conveyor device 101 comprises a base frame 110 which carries guide rails 114, 115, together forming a track of the conveyor device 101. A plurality of carriers 111 positioned consecutively in a conveying direction, flexibly connected to each other and forming an endless conveying line for loading of objects 102, 104 on each of the carriers 111. The objects may be small objects 102 and large objects 104. Each carrier 111 at the central section of its front side 112 and the central section of its rear side 113 is pivotably connected to the adjacent carrier 111. A cross-belt conveyor is mounted at a top end of each carrier 111 for receiving and subsequent delivering of an object. The cross-belt conveyor has an endless-loop conveying belt 105 which runs over two rollers that are separately positioned and extend in the conveying direction of the conveyor device 101. The top surface 103 of the cross-belt conveying belt 105 forms a rectangular support surface. An electric motor drives one of the cross-belt rollers in such a manner that the support surface 103 of the cross-belt conveying belt 105 moves in the direction perpendicular to the transport direction toward a predetermined delivery station. Each carrier 111 is supported and guided by means of the wheels 116 at its lower end section on left-hand side support / guide rail 114 and right-hand side support / guide rail 115, which determine an endless track path. Each support surface is delimited by upright side walls 128 at both ends, seen in the transport direction, for preventing objects 102, 104 from sliding off the support surfaces 103 in the transport direction. As shown in Figs. 2A / B, each carrier 111 may comprise two (or more) support surfaces 103, wherein each support surface 103 is delimited by side walls 128, and where a side wall 128 may be a shared side wall 128 between two adjacent support surfaces 103 of one carrier 111. The side walls 128 are normally in the upper position as shown in Fig. 2A. But when a large object 104, which may have a dimension in the transport direction which is larger than the distance between two side walls, is to be placed on the conveyor device, one or more side walls may temporarily move down to accommodate the large object 104. It should be noted that also small objects 102 that are loaded onto the conveyor at the location of a side wall 128 may cause the side wall 128 to be moved down. This allows for a more flexible manner to use the conveyor device, and potentially increase its capacity, in particular if the conveyor is moved at very high speeds. The side walls 128 are provided with sloping upper edges 304 (see Fig. 5C) near both outer ends. Since the objects 102, 104 are usually loaded onto the support surfaces 103 in a horizontal movement from a side of the conveyor. In that case, if the object 102, 104, will exert a force on the sloping edge 304 of the side wall 128 which is then converted into a downward force to move the side wall 128 to the lower position. This arrangement is not necessary in embodiments wherein the walls are actively operated and moved by means of sensor or a timer devices and mechanical actuators. According to the embodiment of Figs. 3A / B the side walls 128 are provided with vertical slots 301 which are engaged by pins 302, such that the walls are allowed to move up and down relative to the carrier 111. A spring 303 is provided between the carrier 111 and the side wall 128 in order to exert an upward force on the side wall 128 so that it normally will be held in the upper position as shown in Fig. 3A. The force of the spring is chosen such that for most objects 102, 104 the force of their weight is sufficient to move the sides wall 128 to the lower position as shown in Fig. 3B. Also according to the embodiment of Figs. 4A / B the side walls 128 are provided with vertical slots 301 which are engaged by pins 302, such that the walls are allowed to move up and down relative to the carrier 111. A solenoid 401 is provided on the carrier 111 and is connected to a pin 402 that holds the side wall 128. Normally the solenoid 401 holds the side wall 128 in the upper position as shown in Fig. 4A. If an object is placed on the support surfaces at the location of a side wall, this may trigger a sensor, which is connected to the solenoid, or alternatively, a controller may know when an object 102, 104 is to be placed at the location of a side wall 128, and may operate the respective solenoid 401 to move the side wall 128 to the lower position, as shown in Fig. 4B. Once the object 102, 104 is offloaded from the conveyor, the solenoid is operated in the same manner to move the side wall to the upper position, as shown in Fig. 4B. Also according to the embodiment of Figs. 5A / B the side walls 128 are provided with vertical slots 301 which are engaged by pins 302, such that the walls are allowed to move up and down relative to the carrier 111. Each side wall 128 is further provided with a locking slot 501 which extends parallel to the vertical slots 301, and the carrier is provided with a locking pin 502. The locking slot 501 has a narrower part 504 wherein the locking pin is clamped with a holding force, which is sufficiently high so that the wall 128 is normally held in the upper position. The sides of narrower part of the locking slot 501 may be provided with spring elements 509 to exert said holding force. The holding force is low enough to allow the wall to be moved to the lower position, as shown in Fig. 5B, by the force of an object 102, 104 which is placed on the conveyor at location of the side wall 128. In that lower position the locking pin 501 extends in the wider part 503 of the locking slot 501. As shown in Figs 5D / E, actuators 507 which are attached to the frame 110 may operate an actuator guide 508 to move from an inactive state as shown in Fig. 5D to an active state as shown in Fig. 5E. In the active state the actuator guide forces a wheel 506, which is connected to the side wall 128 by means of an arm 505, to move upward, and thereby to move the side wall 128 upward to the upper position. Depending on the configuration of the conveyor device, instead of multiple operated actuators 507, the conveyor device may also be provided with one or more static actuator guides 508, which is / are located between the last offloading location and the first onloading location for products 102, 104, which static actuator guides will move any side wall 128 which is still in the lower position back to its normal upper position. 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 substantially the same function in substantially the same way to yield substantially the same result as the element specified in the claims.

Claims

C L A I M S 1. A conveyor device (101) comprising: an endless track which follows a track path in a transport direction; a plurality of carriers (111) distributed in a closed loop along said track, wherein each carrier (111) comprises at least one rectangular support surface (103) for carrying one or more objects; wherein each support surface (103) is delimited by upright side walls (128) extending along two opposite sides of said support surface (103) in upward direction up to a wall height, said sides of said support surface extending perpendicular to said transport direction; driving means for moving said plurality of carriers (111) along said track; characterized in that at least one of said side walls (128) is movable between an upper position and a lower position, wherein in the upper position the side wall (128) extends up to said wall height in said upward direction from said edge of the support surface, and in said lower position an object, which is supported by said support surface (103), is allowed to extend over the respective edge of said support surface (103) in a substantially flush manner towards the respective adjacent support surface (103) to be supported thereby.

2. The conveyor device according to claim 1, wherein said side walls (128) are held in the upper position by means of a holding force between the wall (128) and the carrier (111), which force is chosen to have a value such that an object with a predetermined weight acting on the wall (128) will force the wall (128) to move to the lower position against said holding force.

3. The conveyor device according to claim 1 or 2, wherein said conveyor device is provided with at least one actuator which is arranged to move side walls from the lower position to the upper position.

4. The conveyor device according to any of the claims 2 or 3, wherein said holding force is a spring force between the wall (128) and the carrier (111), which spring force is chosen to have a value such thatan object with a predetermined weight acting on the top of the wall (128) will force the wall (128) to move to the lower position.

5. The conveyor device according to any of the preceding claims, wherein said side walls (128) are held in the upper position by means of the holding force of an actuator positioned between the wall (128) and the carrier (111), which actuator is arranged to be operated in order to allow the wall (128) to move to the lower position.

6. The conveyor device according to claim 5, wherein said actuator comprises a solenoid.

7. The conveyor device according to any of the preceding claims, wherein said actuator is connected to one or more sensors, which are arranged to sense an object being moved onto the side wall (128).

8. The conveyor device according to any of the preceding claims, wherein said actuator is connected to a control unit of the conveyor device, which control unit operates the switch based on timing information about an object being moved onto the side wall (128).

9. The conveyor device according to any of the preceding claims, wherein each carrier comprises at least two of said support surfaces (103), wherein each support surface (103) is delimited by upright side walls (128) extending along two opposite sides of said support surface (103) in upward direction up to a wall height, said sides of said support surface (103) extending perpendicular to said transport direction, wherein at least a side wall (128) which extends between said support surfaces (103) is movable between an upper position and a lower position.

10. The conveyor device according to any of the preceding claims, wherein all the side walls (128) are movable between an upper position and a lower position.

11. The conveyor device according to any of the preceding claims, wherein said support surfaces (103) are formed by top surfaces (103) of respective cross-belt conveyors (105).

12. The conveyor device according to any of the preceding claims, wherein the track path comprises at least one straight section (203) and multiple curved sections in horizontal direction.

13. The conveyor device according to any of the preceding claims, wherein the conveyor device (101) is a sorter device (101).