Networked motorized drive roller conveyor

Abstract

A motorized drive roller conveyor includes an upstream zone and a downstream zone, with each zone having a drive roller, an idler roller that is driven by the drive roller, and a sensor. The upstream zone and the downstream zone are controlled by a card, which measures a gap between a first item on the conveyor and a second item on the conveyor by beginning a counter when a trailing edge of the first item passes the sensor of the upstream zone and stopping the counter when a leading edge of the second item passes the sensor of the upstream zone to generate a counter value. If the first item is stopped in the downstream zone, the card of the upstream zone causes the drive roller of the upstream zone to advance the second item into the downstream zone for a distance derived from the counter value before stopping the transportation of the second item.

Description

BACKGROUND AND SUMMARY OF THE INVENTION[0001]The present invention relates generally to a networked motorized drive roller conveyor.[0002]Conventional conveyor control systems utilize a central Programmable Logic Controller (“PLC”) mounted in a central control panel. This type of system requires control devices, e.g., photo-eyes, solenoid valves, and motor starters, to be terminated at the main control panel. A typical control system utilizing a PLC requires several hundred to several thousand feet of control wiring, which requires significant time, labor and money to route and terminate the wiring. In addition, the PLC requires specialized knowledge, e.g., knowledge of ladder logic, and familiarity with the many different interface requirements unique to each manufacturer's product. Moreover, since there is a central controller, response time with respect to the control devices may be increased because the single processor must account for all operations occurring within the system...

AI Technical Summary

Benefits of technology

The present invention is a networked, distributed control system for conveyor systems that use MDR technology. The system has many advantages over conventional control systems, including lower power consumption, noise reduction, and a decreased need for maintenance. The system can grow without worry of overtaxing a centralized controller and has parallel control capability that minimizes response time issues common to conventional PLC-based systems. The system can handle the basic MDR conveyor drive and accumulation responsibilities, reducing the wiring needed for the system, implementation time, and cost while maintaining a centralized diagnostic capability. The system also has the ability to control the size of gaps between items on the conveyor system, which reduces the number of items that can be accumulated on the conveyor, providing higher accumulation efficiency.

Problems solved by technology

A typical control system utilizing a PLC requires several hundred to several thousand feet of control wiring, which requires significant time, labor and money to route and terminate the wiring.

Having multiple PLCs in this environment creates other undesirable issues as single point diagnostics are difficult to implement.

However, prior to the present invention, MDR systems lacked the ability to control the size of gaps between items on the conveyor system.

Prior art systems are also limited to transporting “Items” that are shorter in length than a single “Zone”.

The elimination of gaps between items on the conveyor system is desirable, in that gaps reduce the number of items that can be accumulated on the conveyor, providing lower accumulation efficiency.

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