| 摘要 |
The present application discloses a method and apparatus for conveying parcels on a plurality of transport units (32) moving in a conveying path (30) between an induction station (26) and a discharge station (28). Each transport unit has a driven carrier belt (36) thereon, which is moveable orthogonally to the conveying path. The induction station includes a plurality of tandem driven induction belts (62), extending at an angle to the conveying path. The discharge station has a plurality of receiving ports (46) positioned along the conveying path. The invention provides the ability to handle parcels having a length greater than the length of a single transport unit by providing the ability to induct such parcel onto two contiguous transport units (32) and to discharge the parcel from the two contiguous transport units to a selected receiving port (46). This may be accomplished by determining whether a parcel has a length less than or greater than a given length. For longer parcels, having a length greater than the given length, the parcel is inducted to two contiguous transport units by operating the induction belts and the carrier belts of the two contiguous transport units in a manner which positions the parcel on the two transport units (Figs. 9-11). The carrier belts of the two transport units are operated in a manner that rotates longer parcels, having a length greater than the given length, in order to position the parcel on the two transport units. This rotation is accomplished by operating the carrier belts of the two contiguous transport units until a parcel is positioned over the leading one of the transport units (Fig. 10). The carrier belt of the leading transport unit is then stopped and the carrier belt of the following transport unit continues to operate until the parcel is rotated into position on the two transport units. A parcel conveyed on two contiguous transport units is discharged to a receiving port by rotating the parcel concurrently with discharging that parcel (Figs. 12-14). The rotation is accomplished initially by operating the carrier belt of the forward transport unit while not operating the carrier belt of the trailing unit (Fig. 13). After a time delay, the carrier belt of the trailing unit is actuated in order to complete the rotation and discharge the parcel to the receiving port (Fig. 14). Crossbelt sortation system (25) is provided with a transport unit test station (96) that is positioned adjacent to the conveying path. The purpose of the test station is to test movement of the carrier belt associated with individual ones of the transport units passing the test station. Each of the transport units (32) includes a magnet (204a, 204b) that moves in proportion to the linear speed of the carrier belt (36) associated with that transport unit. The test station includes a sensor (200) that senses the magnet of a transport unit passing the test station. The sensor includes at least one Hall-effect cell (208a, 208b) and a magnetic antenna (210) coupled with the Hall-effect cell. <MATH> |
