Airport Application

Posted on Monday, October 24, 2016 in Case Studies


Sage Parts and UEA Shift Into Gear

By Kyle Riegel, R&D Engineer, UEA

This article originally appeared in Ground Support Worldwide.

The culmination of that partnership: A heavy-duty shifter—designed specifically for airline baggage handling tractors—that offers increased reliability and a longer lifespan.

It all started when a major U.S. airline approached Sage Parts, a company long-known for their replacement parts for ground support equipment, for a solution to a longstanding—and costly—issue.

Cable Shifter WearThe problems: (a) the shifters in the airline’s baggage handling tractors could not withstand the extreme conditions characteristic of the airport ramp environment; and (b) aggressive shifting by baggage handlers led to excessive wear and tear on the shifters’ levers.

“The original shifters work well when used for their original intent—material handling in enclosed, indoor spaces,” Michael Bloomfield, executive vice president of Sage Parts, says. “But on ground support equipment, they have a very short life. They aren’t suited for long cycle hours and the outdoors with exposure to ramp chemicals, UV light and everything else airports throw at them.”

The OEM shifters in the baggage tractors rely on a metal shift lever sliding against a metal gate for shifting operation. The continuous metal-on-metal sliding action leads to the lever essentially being sawed off—a dangerous, costly part failure.

Another failure point airlines were noticing in the OEM shifters, according to Bloomfield, was a rubber grommet that provides resistance during shifting. The grommet weathered quickly in airport environments, making it easy for an operator to accidentally shift.

Sage Parts sought out a partner that could help design and manufacture a heavy-duty shifter. This led the company to United Equipment Accessories (UEA), which engineers and manufactures standard and custom solutions for shift controls and other components.

“We already manufacture shifters for equipment in other industries,” Daniel Hanawalt, business development manager at UEA, says. “We knew it would be a unique challenge to work toward designing a durable shifter for such a harsh environment where shifters really take a beating.”

Cable Shifter Side

To solve the problems facing them, Sage and UEA worked from two different angles. First, reduce wear, and second, capture the wear. They conducted tests to find a solution that would either eliminate the wear altogether or would transfer minimal wear onto a part that could be easily replaced.

After intensive testing and several iterations, the two companies co-developed an airline-specific solution—the RAMPTECH® Heavy Duty Shifter—which is manufactured by UEA and sold by Sage Parts.

“The shifter really adds value for the airline customer,” Bloomfield says. “We turned a high-failure component into one that has a long life, significantly reduces maintenance costs, and greatly contributes to ramp safety.

The shifter is designed to be a replacement part, so it integrates seamlessly with the existing equipment. Airlines using it are seeing less tractor downtime, fewer shifter changes, fewer vehicle accidents and less punishment on tractor drivetrain.

The advanced design, which uses a versatile nylon material, minimizes abrasion from sliding metal parts repeatedly rubbing together. The shifter’s synthetic rubber spring-like bushing withstands extreme environmental conditions, provides UV protection and allows the lever to snap in and out of the neutral position while keeping the lever safely locked in forward or reverse when needed.

Internal testing conducted by UEA showed very little wear on the redesigned shifters after a simulated three years of use (110,500 cycles, reverse to near forward). The simulation test shifted the shifter from reverse to near forward with a force of 14 pounds, while constantly pulling the shifter into the neutral position with a force of 5 pounds. The air cylinder was positioned so the lever couldn’t fall into the neutral slot.

Separately, Sage’s internal testing found the RAMPTECH® shifter has a 20.5 percent lower wear rate than the OEM shifter on airline tractors, coming in at a 3.1 x 10-10 m2/N wear rate.

Cable Shifter Back“Sage Parts focuses on reducing costs for their customers, and together, we achieved that,” Hanawalt says. “It also feels great when you know your products help increase people’s safety.”

For even more safety, the forward, neutral and reverse symbols are illuminated by an LED light for clear and easy visibility, and the electric safety neutral switch increases safe operation of the shifter.

The relationship between Sage Parts and UEA has proven to be as long lasting as the replacement shifters. The two companies have already been working together for nearly three years.

“Sage Parts brought knowledge of the punishments parts received in this specific application,” Bloomfield says. “UEA is a true expert in shifters, and we liked cooperating with an expert.”

The RAMPTECH® Heavy Duty Shifter can be found in airports across the country and world. While it’s too early for conclusive data, these shifters are already anecdotally extending the usable life, improving the safety and lowering the cost of ownership of the airline’s baggage tractors.

Sage Parts and UEA continue to collect data and feedback from the field and internal testing to make additional improvements to the shifter.

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