The invention relates generally to power-driven conveyors and more particularly to roller transfers between conveyors.
In the parcel-handling industry masses of parcels and envelopes are conveyed to processing stations that perform specific functions, such as applying or reading labels. Many such processing stations can handle only one parcel at a time. Singulators convert a mass flow of parcels into a single file. But often parcels in a mass flow are stacked atop one another. And singulators, which singulate the flow, are not normally designed to unstack stacked parcels.
One version of a destacking conveyor embodying features of the invention comprises a first conveyor conveying a mass flow of articles off an exit end at a first elevation. A roller transfer system at the exit end of the first conveyor at the first elevation receives articles from the first conveyor. The roller transfer system extends in a length direction from an upstream end proximate the exit end of the first conveyor to an opposite downstream end. The roller transfer system includes a plurality of closely spaced rollers rotatable on axes arranged to transfer articles away from the exit end of the first conveyor. A second conveyor at a second elevation lower than the first elevation below the roller transfer system receives articles dropping off the roller transfer system. The axial lengths of the rollers decrease monotonically from the upstream end to the downstream end of the roller transfer system.
The first conveyor 10 feeds the articles 12 onto a roller transfer device 16, which is constructed of an array of side-by-side rollers 18 closely spaced apart in a conveying direction 20. The rollers 18 rotate on parallel axes 22 that are perpendicular to the conveying direction 20 and to a length direction 21 of the roller transfer device 16. Alternatively, the rollers could be arranged with their axes oblique to the length direction 21. As shown, all the rollers 18 are at the same elevation as the exit end 15 of the first conveyor 10. For a better grip on the articles 12, the rollers 18 could have a high-friction periphery made of rubber or an elastomer, for example. The rollers 18 may all be passive rollers, in which articles 12 advance across the rollers by their own momentum or by back pressure from trailing articles. If all the rollers are passive, the array could be tilted slightly downward from an upstream end 24 to a downstream end 25 in the length direction 21 of the roller transfer device 16 to receive the aid of gravity in conveying articles 12 along the roller transfer device. One or more of the rollers 18 could be motorized rollers. If one or more are motorized and others are idle, each idle roller could be connected to one or another of the motorized rollers by transmission belts or gears. In that way all the rollers would be activated together. As another alternative, the rollers 18 could be made of or include an electrically conductive material. A linear-motor stator 26 close to the array of rollers 18 generates a magnetic flux wave that induces eddy currents in the electrically conductive rollers 18. The reaction field caused by the eddy currents interacts with the stator's magnetic flux wave to generate a torque that rotates the rollers 18. Thus, the electrically conductive roller 18 acts as a rotor and forms a linear-induction motor with the stator 26. If the rollers include soft-iron elements or permanent magnets, they would act as rotors and form reluctance motors or synchronous motors with the stator 26.
As better shown in
A discharge conveyor 30 is disposed at a lower elevation than the exit end 15 of the first conveyor and the downstream end 25 of the roller transfer device 16. The discharge conveyor 30 receives articles 12 that drop from the roller transfer device 16 over the edge 27. The oblique edge 27 of the rollers 18 at their second axial ends 29 provides a longer drop-off edge than would be provided if all the rollers were the same length. For this reason and because the edge is oblique to the length direction 21, stacked articles are more likely to become unstacked in their drop to the discharge conveyor 30.
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Entry |
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Interroll Conveyor Lines, catalog excerpt, Feb. 2011, Interroll Holding AG, Sant'Antonito, CH. |
International Search Report and Written Opinion of the International Searching Authority, PCT/US2016/029150, mailed Aug. 9, 2016, Korean Intellectual Property Office, Daejeon, Republic of Korea. |
Number | Date | Country | |
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20160332824 A1 | Nov 2016 | US |