Abstract:
Methods for preparing parcels for final sorting. The methods include dividing a mass flow of parcels into individual streams, separating and singulating the parcels in each stream, delivering each stream at a steady rate to a human operator that faces and culls the parcels, reading identifying indicia on the parcels, delivering the scanned parcels to a presorter in parallel lanes, and selectively discharging parcels from the lane closest to a side of the presorter off the side at multiple discharge points.

Description:
BACKGROUND 
     The invention relates generally to power-driven conveyors and more particularly to methods for preparing parcels for sorting. 
     In typical parcel-sorting systems, a bulk flow of parcels (envelopes and packages) is distributed to a number of individual conveyors. A human operator at each conveyor arranges the parcels on an adjacent conveyor so that they are facing up and in a single file. The face-up single files of parcels are inducted onto a main conveyor where they are scanned so that they can be appropriately sorted downstream. This process is labor-intensive and paced by the operators. 
     SUMMARY 
     According to one aspect of the invention, a method for handling parcels comprises:
     (a) separating a mass flow of parcels into two or more individual streams of parcels;   (b) singulating the parcels in each of the individual streams of parcels; (c) delivering each individual stream of parcels at a steady rate to a corresponding individual culling and facing station; (d) manually culling unacceptable parcels from the individual stream of parcels at each culling and facing station; and (e) manually facing acceptable parcels at each culling station so that identifying indicia on the parcels can be read downstream.   

     According to another aspect of the invention, a method for handling parcels comprises: (a) feeding two or more streams of singulated parcels onto a sorter in parallel lanes; (b) discharging a parcel from a spot in a lane closest to a side of the sorter off the side of the sorter at a selected of multiple discharge points; and (c) diverting a neighboring parcel from an adjacent lane to occupy the spot vacated by a parcel discharged off the side of the sorter for subsequent discharge from the lane closest to the side of the sorter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These features of the invention are described in more detail in the following description, appended claims, and accompanying drawings, in which: 
         FIG. 1  is a top plan view of a conveyor system embodying features of the invention; and 
         FIG. 2  is a block diagram of the conveyor system of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     A conveyor system embodying features of the invention is shown in  FIG. 1 . In the conveyor system  10 , pallet loads of parcels  12  are emptied by unloaders  14  and deposited onto a bulk conveyor  16 , which may be a chute or a conveyor belt, such as an in-line roller belt, that allows the parcels to accumulate with low back line pressure when the upstream supply of parcels exceeds the downstream demand. The bulk flow of parcels is metered downstream in a metering conveyor  18 , such as a friction-top belt operated at a predetermined speed. The metered bulk flow of parcels is fed onto a separator  20 , which singulates the parcels from the metering conveyor into two streams. 
     The separator may be realized with a two-lane, angled-roller centering belt or roller conveyors arranged in a similar pattern  22  followed by an angled-roller alignment belt or roller conveyors arranged in a similar pattern  24  that aligns parcels on each half of the belt against side rails  26 . Rollers in the two-lane centering belt  22  are actuated to rotate in the direction of arrows  28  to direct the mass flow of parcels into two single-file streams in the middle of each lane. The single files of parcels are then aligned against the opposite side rails  26  by the alignment belt, whose rollers are actuated to divert parcels toward the outer sides of the conveyor as indicated by the arrows  30 . The alignment belt may be run at a higher speed than the centering belt to increase the separation between consecutive parcels in each stream. 
     The two streams of parcels are fed to a buffer conveyor  32 , which may be a chute or an in-line roller conveyor belt, to allow parcels in the two lanes to accumulate as necessary. The buffer conveyor  32  feeds the two lanes of parcels to a second metering conveyor  34  set to run at a predetermined speed to release the two streams at a fixed, steady rate to a pair of human operators  38 —one for each stream—manning a facer conveyor  36  at individual culling and facing stations. In this way, the process is paced by the system and not by the operators. 
     Each human operator culls and faces the parcels in his assigned stream. Trash and parcels that are unacceptable (e.g., oversized or overweight) with downstream processing equipment, that are unlabeled, or that are otherwise problematic are culled from the stream by the operator. The operator also faces acceptable parcels with identifying indicia, such as printed labels, oriented so that they may be read by a video scanner downstream. The operator also singulates any side-by-side or piggyback parcels not completely singulated by the separator. 
     The two culled, faced, and singulated streams of parcels are fed by the facer conveyor  36  onto a scan conveyor  40 , shown as a horse-shoe belt in this example for a compact footprint. But the scan conveyor segment could be linear. The scan conveyor can run at a higher speed to increase the gap between consecutive parcels in each stream. A scanning station  42  including at least one camera positioned over the scan conveyor monitors the two streams and reads the label on each parcel. The scan conveyor feeds the two streams of read parcels onto an induction sorter  44 , which sorts the two lanes of parcels to multiple discharge points, such as induction conveyors  46  along one side of the induction sorter. 
     The induction sorter may be realized by a range of technology including a roller belt such as an INTRALOX® Series 7000 sorter belt and roller-activation system  47 . The roller-activation system includes a series of individually actuated roller-activation mechanisms that control the rotation of the belt rollers in the sorter belt. The mechanisms are sequentially disposed in individual zones along the length of the induction sorter in each lane corresponding to the induction conveyors  46 . The induction sorter selectively discharges parcels in the right-hand lane  48  off the conveyor belt and onto a selected induction conveyor  46 . Once a spot in the right-hand lane has been vacated, the sorter can move a parcel from the left-hand lane  49  to the right-hand lane for diversion onto one of the induction conveyors. If all the induction conveyors  46  are full or a parcel is missorted, the induction sorter  44  delivers the parcel off its end  51  to a key station operator  50 . Misread and unread parcels are also routed via a conveyor  54  to the key station operator  50 , who can then manually key the received parcels and load them onto a final induction conveyor  46 F or send them to a remote encoding station for keying. Parcels rejected downstream may also be sent to the key station operator via a final return conveyor  56   
     The induction conveyors  46 , which are shown as angled obliquely relative to the lanes of parcels in the main conveying direction of the induction sorter  44 , convey the parcels to downstream processing via a tray conveyor  54 . 
     The block diagram of  FIG. 2  provides an overview of the process. A bulk flow of parcels is split into two separated streams of parcels. Each stream is buffered and metered for delivery at a predetermined rate to a human operator. Each operator culls unacceptable items from the stream, faces the parcels so that they can be properly scanned, and singulates any residual unsingulated parcels. The two streams of parcels travel side by side through the scanning station where their labels are read. The scanned parcels are delivered in two streams to the induction sorter, which sorts the parcels from both streams off the sorter. 
     Although the invention has been described in detail with respect to a few preferred versions, other versions are possible. For example, the bulk parcel flow could be separated into three or more streams, rather than just two. As another example, the cross belt sorter could have more than two lanes and corresponding actuation mechanisms to handle more streams of parcels. Furthermore, the induction sorter could sort to discharge points on both sides. The induction conveyors may be oblique to the induction sorter as shown or perpendicular.