Above: A bundle of beams discharges on a saw’s outfeed transfer arms while one beam exits the saw on a roller conveyor

May 2023- Automated conveyor systems become more common throughout service centers and fab shops

A primary focus for CEOs is increasing productivity and improving safety. To this end, metal service centers and fabricators continue to mechanize their material handling operations, especially with today’s challenges when hiring and retaining skilled workers. “There’s a revolving door going on in the workforce,” says Sales Manager Patrick McCallin at Steel Storage Systems Inc. The Commerce City, Colorado-based company’s line of material handling components include idler and powered roller conveyors, transfer and cross conveyors, measuring systems, and accessories, and Steel Storage can design and build custom conveyors, including systems with automated controls. “If customers come to us with an unusual application or layout issues such as sloped floors or bay columns they need to get around, we come in and develop a custom-engineered solution for different warehouse footprints,” McCallin says. The conveyors Steel Storage provides still require workers to, for example, operate the controls to move material through the machining process, interact with the machine, cut the material and index it, McCallin notes. “Everything obviously centers around having the human component on that.” Nonetheless, many end users want more of a hands-off application, he says. “They don’t want the employees touching the material, which kind of goes hand in hand with powered conveyors and automation. If you are going to do that, you’re going to need a machine that can take the basic material, process it and discharge it.”

The types of equipment that are integrated with the company’s conveyors primarily includes saws and drill lines, as well as beam coping machines, McCallin says.

       A dual-lift accumulation transfer conveyor with load rails is for loading round pipe with a forklift.

       A saw infeed roller conveyor with transfers is for accumulating large structural beams up to 60-feet long.

WHAT’S YOUR TYPE?

When looking at the different types of conveyors offered, transfer and cross conveyors are available to feed and discharge material. They comprise a series of arms with a large, powered chain linked to a common drive shaft, which transfers the material laterally. According to McCallin, transfer arms enable a saw to process more material because they accumulate material to the conveyor bed, bring it to the saw for cutting and discharge material from the outfeed roller conveyor. Essentially, a transfer conveyor is a quick and effortless way for an operator to move material from the saw so it can be cutting the next piece and improve efficiency. “The transfer allows the saw to stay productive without going idle.”

Roller conveyors are another option, which are furnished in modular sections that measure 10 feet or less and bolt together to form any continuous length required. One function for a roller conveyor, McCallin says, is to move material from one bay to another or from inside a building to outside without having to put it on a flatbed trailer or forklift. Steel Storage also manufactures bar and pipe loading and discharge conveyors for cut-to- length equipment, he notes. “They’ll cut the material down to a specific size, stack it on top of each other and then our conveyor will increase accumulation and assist in moving it from one space to another.” McCallin adds that if a customer has a specific requirement for round material, such as hot-rolled or cold-finished bar, a bar and pipe loader indexes individual pieces to accumulate them on a roller conveyor and forward them to the saw for processing. “If they’re cutting slivers of material, we would design the outfeed sections appropriately, so it would be a table where the small wafers of material will either fall into a bin or, if they’re cutting a lot of material, we would create a conveyor with a push-bar assembly.” Developing an automated process for conveying structural materials such as tubes and beams, however, is more challenging than one for bar products, according to McCallin, because they take up a significant amount of space and are typically longer. Sawing standard lengths, such as 20-footlong bar into 1/2-inch sections, enhances an end user’s ability to automate a process. Using an automatic saw, the user can “cut that all night long or set the saw and walk away from it.”

CAUSE NO HARM

Built-in interlocks and other safety devices can monitor the sawing operation and trigger an alarm and automatically stop the operation should a problem occur, he adds. McCallin emphasizes the need for safety when workers are around an automated material handling system with lots of moving pieces. The company has responded to the concern. He cites one recent project that required stacking of heavy material in which most of the design focused on safety. Steel Storage incorporated light curtains as an automatic emergency-stop solution that requires an operator to take action to restart the conveyor.

       A roller conveyor safety gate in the up position allows egress through a 130-foot-long saw infeed conveyor. Lifting the gate pauses system operation for safe passage.

“If an operator walks within the light curtain, the sensor will see the operator getting near the equipment and shut off automatically.” McCallin describes light curtains as a proactive approach to safety, especially when compared to previously used limit switches that are built into a roller conveyor and stop the equipment when an operator steps on a motion-sensor pad. “Well, if that operator were to step on the material on the roller conveyor, he wouldn’t be touching that pad anymore and the machine would decide to run, so that just invites a scenario for disaster.” Other safety devices Steel Storage offers are a pull-cable emergency stop along a roller conveyor that will disable the conveyor from driving, and safety gates for egress that shut down and restart a conveyor when raised and lowered, respectively, he explains. Apart from safety, strides continue to be made into improving automated conveyor systems. “We’re working on the new electrical design where it will have an open I/O for other machine tool equipment to integrate with,” McCallin says. “What we want to do is build a conveyor system around that.” Although it depends on the material being cut and the length of cuts needed, he admits a system that provides completely unattended, or lights-out, operation is not available. “We’re still not quite there yet where it’s a fully automated solution but we are actively pursuing it.” MM

Steel Storage Systems Inc., 800/442-0291, http://steelstorage.com/