Patent Description:
The increasing demand for next-day delivery of articles such as parcels, packages, and letters requires high-throughput sorting systems to rapidly direct articles received from multiple sources to selected destinations.

<CIT> discloses that in a method for changing the conveyance direction of products tiered on the pallet in a branched part and a meeting part or a corner part of a pallet conveyance conveyor, a pallet conveyance direction change device having a plurality of skew rollers capable of setting a rotation speed and an oscillation angle arbitrarily is provided in the branched part and the meeting part or the corner part to set a rotation speed and an oscillation angle of a plurality of skew rollers in accordance with a weight of products tiered on the pallet when the conveyance direction of the products tiered on the pallet is changed.

<CIT> shows a matrix warehouse control method and discloses the preamble of claim <NUM>.

One version of a grid sorter embodying features of the invention comprises a plurality of first conveyor lines arranged in parallel in a first direction and a plurality of second conveyor lines arranged in parallel in a second direction perpendicular to the first direction. The first and second conveyor lines intersect at a plurality of intersections to form a grid. The first conveyor lines include series of first conveyors, and the second conveyor lines include series of second conveyors. At least some of the first and second conveyors are omnidirectional-roller sorters disposed at selected intersections. Each of the swivel sorters includes a plurality of omnidirectional rollers. A controller controls the omnidirectional rollers to direct articles along selected conveying paths on the omnidirectional-roller sorters. A plurality of discharges adjacent at least some of the omnidirectional-roller sorters in the first and second conveyor lines receive articles from the omnidirectional-roller sorters.

Another version of a grid sorter comprises a plurality of first conveyor lines arranged in parallel in a first direction and including a plurality of first bidirectional conveyors operable to convey articles in or opposite to the first direction and a plurality of second conveyor lines arranged in parallel in a second direction perpendicular to the first direction and including a plurality of second bidirectional conveyors operable to convey articles in or opposite to the first direction. The first and second conveyor lines intersect at a plurality of intersections to form a grid. A plurality of omnidirectional-roller sorters are each disposed at one of the intersections between two of the bidirectional conveyors in one of the first conveyor lines and between two of the bidirectional conveyors in one of the second conveyor lines. Each of the omnidirectional-roller sorters includes a plurality of omnidirectional rollers, which are controllable to direct articles along selected conveying paths on the omnidirectional-roller sorter. A plurality of discharges are disposed in the grid between the first and second conveyor lines to receive articles from the swivel sorters.

One version of a grid sorter embodying features of the invention is shown in <FIG>. The grid sorter <NUM> comprises four columns of north-south (N-S) conveyor lines C1-C4 and three rows of east-west (E-W) conveyor lines R1-R3. Four columns and three rows are used as just one example to illustrate the operation of the grid sorter. The four N-S conveyor lines C1-C4 are arranged in parallel, and the three E-W conveyor lines R1-R3 are arranged in parallel, perpendicular to the N-S conveyor lines to form a conveyor grid. The N-S conveyor lines convey articles in the grid in or opposite to a first direction <NUM>, and the E-W conveyor lines convey articles in or opposite to a second direction <NUM>. Each conveyor line is composed of a series of aligned conveyor segments including bidirectional conveyors <NUM>, infeed conveyors <NUM> at the ends of each conveyor line, and omnidirectional-roller sorters <NUM> at the intersections of the N-S and E-W conveyor lines. The infeed conveyors <NUM> at the ends of the conveyor lines are arranged to receive and convey articles toward the bidirectional conveyors <NUM> in the interior of the conveyor lines C1-C4, R1-R3.

The omnidirectional-roller sorters <NUM> at the intersections of the conveyor lines C1-C4, R1-R3 include roller assemblies with rollers that are selectively rotatable and pivotable to convey articles in multiple directions-in and opposite to the first and second directions <NUM>, <NUM> and in directions between the first and second directions and their opposites-such as N, NW, W, SW, S, SE, E, and NE; i.e., every <NUM>°. For example, an omnidirectional-roller sorter <NUM> receiving an article traveling from E to W along conveyor line R2 can pass the article forward along the conveyor line in the W direction or can reverse the direction of the article in the E direction. It can alternatively divert the article <NUM>° left or right in the N or S direction onto a N-S conveyor segment <NUM>. Or the omnidirectional-roller sorter <NUM> can divert the article <NUM>° in the NW, SW, SE, or NE directions to an adjacent discharge <NUM> disposed in the grid <NUM> between the N-S and E-W conveyor lines C1-C4, R1-R3. The discharge <NUM> may be openings through which the article drops onto a discharge conveyor below, onto a chute into a receptacle, or even onto another grid-sort level below in a <NUM>-D arrangement. Each discharge <NUM> represents a selected destination for the article. Position sensors <NUM> are distributed throughout the grid as a sensor system configured and adapted to indicate the presence or absence of an article at those positions. Instead of multiple position sensors, a camera with a visioning system could be used as the sensor system configured and adjusted to sense the positions of articles on the grid sorter.

The operation of the grid sorter <NUM> is controlled by a controller <NUM> as shown in <FIG>. The controller <NUM> may be a general-purpose computer, a programmable logic device, or other programmable device with program and data memory. The controller <NUM> receives position signals <NUM> from the position sensors <NUM>. (Alternatively, a camera <NUM> could provide a video signal <NUM> from which the positions of the articles on the grid sorter can be determined by the controller <NUM>. ) The controller <NUM>, acting as a traffic controller, sends motor control signals <NUM> to motors <NUM> driving the infeed conveyors, the bidirectional conveyors, and the omnidirectional-roller sorters. The controller also sends pivot signals <NUM> to swivel actuators <NUM> in the omnidirectional-roller sorters.

A simple example of the operation of the grid sorter <NUM> is shown in <FIG> for two articles. A first article A, indicated by solid squares, heads north at time T = <NUM> on the infeed conveyor at the south end of conveyor line C1. The article A is destined for a discharge D1 between N-S columns C3 and C4 and E-W rows R1 and R2. The controller directs the omnidirectional-roller sorter <NUM> at the C1-R3 intersection to continue conveying the article A north in the N direction onto the adjacent bidirectional conveyor <NUM>, which continues to convey the article north. At time T = <NUM>, the article A is about midway along the bidirectional conveyor. The article A continues to be conveyed north until it is received on the omnidirectional-roller sorter <NUM>', which diverts the article A traveling north along the conveyor line C1 to the east in the E direction on the conveyor line R2. At times T = <NUM>, <NUM>, and <NUM> the article A is conveyed to the east along the conveyor line R2 by two bidirectional conveyors and an intervening omnidirectional-roller sorter <NUM>". After being received on the omnidirectional-roller sorter at the C3-R2 intersection, the controller causes the omnidirectional-roller sorter to divert the article <NUM> to the northeast (NE) direction and into its selected discharge D1. In the meantime a second article B (indicated by circles) is being conveyed south in the S direction on an infeed conveyor <NUM> at the north end of the C2 conveyor line at time T = <NUM>. The article B continues to be conveyed south over an omnidirectional-roller sorter and a bidirectional conveyor <NUM>. Because the article B reaches the omnidirectional-roller sorter <NUM>" at the C2-R2 intersection while the other article A is already on it, the controller stops the bidirectional conveyor <NUM> conveying the article B to prevent the articles from colliding at time T = <NUM>. Once the article A has cleared the omnidirectional-roller sorter <NUM>", the controller restarts the bidirectional conveyor <NUM> in the line C2 to push the article B onto the C2-R2 omnidirectional-roller sorter. Then the controller adjusts the omnidirectional-roller sorter <NUM>" to divert the article B to its selected discharge D2 at time T = <NUM>. The controller could alternatively have chosen a different route for the article A to take to its destination discharge D1 by diverting the article to the east on the conveyor line R3 with the C1-R3 omnidirectional-roller sorter <NUM>. The article A continues to the east at times T = <NUM>', <NUM>', <NUM>' until the C3-R3 omnidirectional-roller sorter diverts the article A <NUM>° counterclockwise to be conveyed north along the conveyor line C3. After time T = <NUM>', the article A is diverted by the C3-R2 omnidirectional-roller sorter to the northeast and into the destination discharge D1. If the controller selects that route for the article A, the other article B does not have to stop for the article A to pass because the routes do not intersect at the same time.

In a grid sorter with many N-S and E-W conveyor lines handling many articles simultaneously, the controller determines the routes for each article to take from a starting point on one of the infeed conveyors <NUM> to a designated discharge <NUM>. With regular position updates from the sensor system, the controller can adjust the routes on the fly and start and stop the infeed conveyors, the bidirectional conveyors, and the omnidirectional-roller sorters or change the directions of the bidirectional and omnidirectional-roller sorters to avoid collisions or alter routes.

One example of an omnidirectional-roller sorter <NUM> embodying features of the invention is shown in <FIG>. The omnidirectional-roller sorter <NUM> includes a plurality of roller assemblies <NUM>, each of which has a roller <NUM> mounted in a frame <NUM> that is pivotable about a vertical axis <NUM>. The roller assemblies <NUM> are mounted to a base plate <NUM> with salient portions of the rollers <NUM> extending above a cover plate <NUM> to support conveyed articles. A swivel actuator <NUM> controls the orientation of the roller assemblies <NUM> by adjusting their pivot angle <NUM>. In this example the swivel actuator <NUM> consists of two linear actuators <NUM>, 51R on opposite sides of the base plate. Each actuator controls the orientation of alternating rows <NUM>, 44R of the roller assemblies <NUM>. Each actuator <NUM>, 51R translates a rack gear <NUM>, 43R through a slide arm <NUM>. The rack gears <NUM>, 43R engage the large ring gears <NUM> on the roller assemblies <NUM>' closest to the rack gears. Pinion gears <NUM> engage the ring gears <NUM> in each row <NUM>, 44R so that the roller assemblies <NUM> in each row pivot together. The rollers <NUM> in the roller assemblies <NUM> are actuated to rotate on their axes of rotation by a rotation actuator, such as a bidirectional motor-driven belt <NUM> contacting the bottoms of the rollers. In this example only one belt is shown serving as a rotation actuator. If, for example, two actuator belts are used, the omnidirectional-roller sorter could be divided into two zones of independently rotated rollers.

Details of an omnidirectional roller in the roller assemblies of <FIG> are shown in <FIG>. The roller assembly <NUM> includes a frame <NUM> supported in a support ring <NUM> and rotatable about a main axis of rotation <NUM>. Openings <NUM> in the frame <NUM> receive small rollers <NUM>. Each small roller <NUM> is paired in rolling contact with a similar small roller received in the opening on the other side of the frame <NUM> to form a mutually-actuating roller set <NUM>. Each roller assembly <NUM> has at least one such mutually-actuating roller <NUM>. In this example, three mutually-actuating roller sets are disposed along the axial length of the frame <NUM> at different orientations. The small rollers <NUM> in each set rotate on parallel minor axes <NUM> skewed relative to the main axis of rotation <NUM> of the frame <NUM>. The outside surfaces <NUM> of the small rollers <NUM> extend slightly beyond the frame <NUM>. And salient portions of the roller assembly extend beyond top and bottom faces <NUM>, <NUM> of the support ring <NUM> to engage articles on the top and rotation actuators, such as belts <NUM>, on the bottom.

An example of swivel actuation is shown in <FIG>. Each roller assembly <NUM> shown in <FIG> has a peripheral ring gear <NUM>. The swivel actuator includes rack gears <NUM> that engage the ring gears <NUM> of the roller assemblies <NUM>. The rack gears <NUM> are formed in a gear plate <NUM> with cutouts <NUM> for the roller assemblies <NUM>. The gear plate <NUM> is translated by an actuating device, such as the linear actuator <NUM> in <FIG>, in a translator direction <NUM> to set the orientation <NUM> of the omnidirectional roller assemblies <NUM>.

Acting together, the swivel actuator, setting the orientation of the roller assemblies, and the rotation actuator, setting the direction of rotation of the omnidirectional rollers in the roller assemblies, allow the omnidirectional-roller sorter to push articles atop the rollers in any conveying direction along a selected conveying path. In particular, the article-divert, or conveying, angle of the omnidirectional-roller sorter with mutually-actuating rollers is twice the pivot angle. One commercial example of an omnidirectional-roller sorter is the Omni-Directional Sorter sold by Intralox, L. of Harahan, Louisiana, U. And further details of various versions of omnidirectional sorters usable in the grid sorter of <FIG> are disclosed in <CIT>.

Another version of a grid sorter <NUM> is shown in <FIG>, in which all the conveyors <NUM> in the first and second intersecting conveyor lines <NUM>, <NUM> are omnidirectional sorters. Discharges <NUM> are disposed within the grid at selected non-adjacent intersections in the conveyor lines <NUM>, <NUM>. In this example the discharges <NUM> are at the intersections of every other first and second conveyor line <NUM>, <NUM>. The swivel sorters 82A on the four sides of the discharges <NUM> sort to the discharges and convey articles past the discharges, while the omnidirectional-roller sorters 82B at the four corners of the discharges do not sort, but convey articles selectively in one of four directions. In this example the omnidirectional-roller sorters <NUM> need only adjust the direction of rotation of the rollers and the sorter's conveying direction and the conveying path followed by articles in four directions as indicated by the arrows <NUM>.

In the grid sorter <NUM> shown in <FIG>, the discharges <NUM> are at one or both ends of the first and second conveyor lines <NUM>, <NUM>. All the first and second conveyors <NUM> within the grid are grid sorters as in <FIG>. The grid sorter <NUM> is shown in this example with three infeed conveyors <NUM> feeding articles into the grid from three sources. In all the examples shown in <FIG>, <FIG>, the grid sorters can convey an article along continuous paths that include all the first and second conveyors.

Claim 1:
A grid sorter (<NUM>) comprising:
a plurality of first conveyor lines (C1-C4) arranged in parallel in a first direction (<NUM>) and including series of first conveyors;
a plurality of second conveyor lines (R1-R3) arranged in parallel in a second direction (<NUM>) perpendicular to the first direction and including series of second conveyors, wherein the first and second conveyor lines intersect at a plurality of intersections to form a grid;
wherein at least some of the first and second conveyors are omnidirectional-roller sorters (<NUM>) disposed at selected intersections, each of the omnidirectional-roller sorters including a plurality of omnidirectional rollers (<NUM>);
a controller (<NUM>) controlling the omnidirectional rollers to direct articles along selected conveying paths on the omnidirectional-roller sorters;
a plurality of discharges (<NUM>) adjacent at least some of the omnidirectional-roller sorters in the first and second conveyor lines to receive articles from the omnidirectional-roller sorters;
a rotation actuator selectively rotating the rollers in the direction of rotation; characterized in that each of the omnidirectional rollers has a direction of rotation and is disposed in a roller assembly (<NUM>) including:
a swivel actuator (<NUM>) selectively pivoting the roller assemblies to adjust the direction of rotation of the rollers at least in and opposite to the first and second directions.