BACKGROUND

The invention relates generally to power-driven conveyors and, more particularly, to a conveyor that employs a vacuum to facilitate conveyance.

Conveyor belts may sometimes include article-supporting rollers to propel conveyed objects in a desired direction as the conveyor belt advances. Conveyor belts with article- supporting rollers may be used for accelerating, diverting, sorting, merging, switching or otherwise moving objects in a selected direction relative to a moving conveyor belt. The rollers are arranged to rotate in line with or perpendicular or oblique to the direction of belt travel. Examples of conveyors using belts of this kind are described in, for example, U.S. Pat. Nos. 6,494,312; 6,968,941; 7,461,739; and 7,971,701.

Conveyed objects may be unsteady on conveyor belts, particularly due to the use of embedded rollers, which may cause the objects to shift or fall.

SUMMARY

A sorting conveyor employs suction to stabilize products on a conveyor belt employing article-supporting rollers. The sorting conveyor includes at least one vacuum chamber housing activators for the rollers in the conveyor belt. Each vacuum chamber is coupled to a vacuum generator, which selectively generates a vacuum in the associated vacuum chamber to pull articles being conveyed against the conveyor belt. A control system may be used to selectively operate a selected vacuum generator when a product is in an associated vacuum zone.

According to one aspect, a sorting conveyor comprises a conveyor belt having a plurality of rollers, a vacuum chamber disposed below the conveyor belt, the vacuum chamber connected to a vacuum generator to create a vacuum zone in a select area above the conveyor belt and a controller for selectively operating the vacuum generator when a conveyed object is in the vacuum zone.

In another aspect, a sorting conveyor comprises an array of vacuum chambers, each vacuum chamber connected to a vacuum generator, an array of activators for selectively activating one or more rollers in a conveyor belt, each vacuum chamber housing a set of activators and a conveyor belt traveling over the series of vacuum chambers. The conveyor belt comprises a plurality of rollers, with at least one roller in contact with an activator.

According to another aspect, a method of conveying objects using a conveyor comprises the steps of conveying an object on a conveyor belt through a plurality of vacuum zones, the conveyor belt comprising an array of rollers, and generating a vacuum in a selected vacuum zone when the object enters the selected vacuum zone.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed systems and methods can be understood with reference to the following drawings. The components in the drawings are not necessarily to scale.

FIG. 1 is a perspective view of a section of a sorting conveyor employing a vacuum according to an illustrative embodiment of the invention;

FIG. 2 is a detailed, cross-sectional view of an actuator and conveyor belt module of the sorting conveyor of FIG. 1; and

FIG. 3 is a block diagram showing the relationship between a sensor, tracker, vacuum generator and controller for the vacuum generator according to one embodiment of the invention.

DETAILED DESCRIPTION

A sorting conveyor employs the use of a vacuum to stabilize conveyed objects. The invention will be described below relative to certain illustrative embodiments, though the invention is not limited to the illustrative embodiments.

FIG. 1 illustrates a sorting conveyor 10 according to an illustrative embodiment of the invention. The sorting conveyor 10 comprises a conveyor belt 102 traveling in a travel direction indicated by arrow 12. The conveyor belt includes embedded rollers 118, which are longitudinally oriented in the illustrative embodiment. The conveyor belt may comprise a plurality of conveyor belt modules 106 hingedly connected together. An array of activators, illustrated as field 104 of angularly adjustable drive roller modules 106 is disposed below the conveyor belt a sorting region. Each roller module 108 may comprise a free-spinning drive roller 125 mounted in a cartridge 130. The cartridge 130 may include teeth 136, shown in

FIG. 2, used to orient the activator. The conveyor belt and activators may be same or similar to the system described in US Patent Number 7,971,701, the contents of which are incorporated herein by reference.

The activators 106 may be selectively oriented and actuated to move product in a selected direction, indicated by arrows 112a, 112b and 112c, relative to the conveyor belt.

Each module includes spaces 109 between the rollers 118 and the module body 106.

The module may include other openings extending from the top surface of the module to the bottom surface, as well.

The array of activators 104 may include spaces 141 between the cartridges 108 and spaces 142 between the cartridges 130 and driver rollers 125.

The sorting conveyor 10 employs a vacuum to stabilize conveyed articles on the conveyor belt 102. In one embodiment, the sorting conveyor 10 includes one or more vacuum chambers 200 housing the activators 104 and arranged in series. Each vacuum chamber is a sealed box comprising side walls 201 and an open top. A set of activators 104 is housed within the side walls 201 of each vacuum chamber 200. The conveyor belt 102 rides over the open tops of the vacuum chambers. Each vacuum chamber further includes a connector 204 in a side wall for connecting the vacuum chamber 200 to a vacuum generator.

A vacuum generator (not shown) is connected to each vacuum chamber 200 to create a vacuum zone above each vacuum chamber. Each vacuum zone may be segregated from the other vacuum zones.

The vacuum generated by the vacuum generator may pull articles being conveyed against the belt 102 to provide stability. The vacuum may be applied to the conveyed articles during straight conveyance, switching, sorting, and-or transitions on and off of the conveyor belt 102.

In one embodiment, the vacuum is a continuous air flow. In another embodiment, the vacuum may be controlled in different regions. For example, each vacuum chamber may be selectively actuated to create a vacuum in a selected vacuum zone.

Referring to FIG. 3, to perform selective actuation of a vacuum zone, the sorting conveyor 10 may include a sensor 230 for sensing of an article of conveyance. The sensor 230 may be a photoelectric sensor or any other suitable sensor known in the art. The sensor may sense the initial positioning of the product. A tracker 240, such as an encoder, may track the location of the conveyed article along the conveying surface. Information from the sensor 230 and tracker 240 is fed to a controller 250 for a vacuum generator 260. Based on the information, the controller may selectively activate a vacuum generator for each vacuum zone. The vacuum generator may generate a vacuum only when a conveyed object is in the vacuum zone and turn the vacuum off when the article exits the vacuum zone. The selective operation of the vacuum conserves energy and resources.

Alternatively, the controller 250 may use information regarding the location of a conveyed object to selectively connect a vacuum chamber 200 to a vacuum generator when it is desirable to create a vacuum in the vacuum zone above the vacuum chamber, and disconnect the vacuum chamber from the vacuum generator when suction is not necessary or desirable in the vacuum zone.