By Richard G. Tact
Public transportation is moving into the future, with increased investment in electric and hybrid vehicles, lightweight, mobile and eye solutions towards Bus Rapid Transit. Representatives from United Safety said the company is willing to help the industry with dynamic seating solutions that are appropriate for transportation to focus on these concepts.
The Infinity Line of Seats in Transition by United Safety is designed to help OEMs and transportation agencies create additional flexibility, customize spacing and capacity, increase range, improve comfort and be more sustainable.
“We have seen a change in the thinking processes of agencies and manufacturers in the transportation industry,” said Joseph Mirbil, President and CEO of United Safety. “It is extremely exciting, and our product designs are designed to support these revolutionary changes in public transportation.”
United Safety first unveiled the Infinity Passenger Seat suspension package, the driver’s seat and the driver’s seat at the US Public Transport Exhibition EXPO 2021 in November.
Infinity means flexibility
John Paul McGovern, vice president of engineering at United Safety, said the Infinity line represents the biggest update to a transition session in more than a decade. Designed for all commercial city buses and especially electric and hydrogen vehicles, McGovern said the passenger seat features an industry-leading lightweight design and is designed for comfort with modern riders in mind.
“The passenger seat has a host of features that are not available elsewhere in the market,” McGovern said. “All Infinity passenger seat cushions can be flipped, locked or locked – a level of customization that allows transport authorities additional flexibility.”
He added that the rollover ability of the seats has a variety of uses, from storing everyday strollers to reducing occupancy following an event like COVID-19. United Safety strives for maximum flexibility and modularity for agencies and manufacturers when designing Infinity.
“The modularity simplifies the amount of parts and reduces maintenance,” McGovern said. “In most of the previous seat designs in the aisle, there was a difference between the forward mobility area – where the complex seats lengthwise face the center of the bus – and the rest of the bus seats. The length The seats are usually inverted seats with various custom brackets, and the rest of the bus seats have a standard design that does not tip over. With Infinity, all passenger seats have the same reversal functionality. “
This shared parts lowers the cost of maintenance – thus reducing the purchase costs for the end user as well.
“With Infinity, we align the design features of a product line with the wiring lines of the transportation industry,” said Ray Malidi, senior vice president of United Safety. “The industry is moving towards sustainability, equality and inclusion, and these concepts are the design criteria for this new line.”
“Seat production reduces the carbon footprint of equipped vehicles, reduces the overall weight of vehicles and improves access for riders with disabilities,” he continued. “It makes buses beyond more efficient in transporting people and aligns the vision and mission of United Safety with those of the transportation industry.”
Driver’s seat and hanging
Another major development for United Safety is the Infiniti seat suspension package and the driver seat package for public transport buses. McGovern said Infinity’s driver’s seat features a new computer-controlled suspension system to deliver the smoothest ride available on all manufacturers’ bus models – as well as the industry’s lowest level of full-body vibration available in the industry.
“To this day, driver’s seats have generally been passive Air suspension seats, “he said.” They contained an air spring, which adjusts the height and spring strength of the seat. They also contained passive shock absorbers at a constant rate, designed to prevent the passenger from hitting really hard at the bottom or top during ‘big bumps’ events. Still, these seats transmit a certain amount of energy to the occupant. “
“that’s new, infinite Seat suspension, “he continued,” really reduces the ability to transfer this energy as much as possible. “
“It’s a much more convenient system that is physically suitable for all the buses and the various transportation environments out there,” he said.
Infinity seat rack for drivers includes dampers that can be controlled at the damping rate via a computer system. Using a package of sensors, including an accelerometer and a position sensor, the suspensions determine the floor movement of the vehicle and perform calculations to update the damping coefficient of the seat in real time. McGovern said it occurs at a scale of milliseconds to optimize passenger travel.
Infinity series design
Mirabile said that while aisle seats have received smooth upgrades in recent years like USB ports, the basic design of aisle seats needs an upgrade in order to meet the needs of current riders. Instead of representing another addition, he said the Infiniti line is meant to be a redesign of the whole concept and functionality of the aisle seat, as well as an eye-catching visual upgrade.
“We believe it creates a long-term sustainable public transportation environment, which is why we have made this investment now to support both our bus builders and our customers going forward,” he said. “We think it will lead to a continuous increase in the number of passengers, and thus to more bus lines. These changes increase people’s mobility, and we believe that a whole new wave of passengers will see buses as a futuristic or modern transportation option.”
The engineering of the Infiniti passenger seat began with industrial design and finding a purposeful look and functionality. Then it was a matter of doing the mechanical design, or moving from the conceptual stage to the practical. The weight optimization effort included finite element analysis (FEA) and other simulations.
“Every component in the complex has been analyzed for optimization purposes, including a full suite of FEA virtual testing,” McGovern said. “The parts were prototyped using 3D printing, and then parts and components were released for final design and manufacture. It was an innovative design process, with many virtual simulations to prevent excessive prototype changes.”
McGovern said the Infinity driver and suspension seat design was nearly three years in the making. The first challenge was to design and implement a rack with extremely low friction. It took a few design iterations, as the performance goal would not be possible with a large, sticky rack that contained significant free play and friction. United Safety’s engineering team achieved this feat with computer-aided design simulation followed by numerous physical testing experiments.
From there, McGovern said the team worked through the mechanics of shock absorber location, shock type movement ratios, mounting types and other complexities.
“It was no small task to design this seat, but it was achieved and now we are working on the volumetric production process.”
“When I interview transport managers, they say they want to increase the width of the aisle and have more comfortable seating for the passenger – that they are competing destinations,” Maldi said. “It is not usually possible to do this with capacity, and yet our engineers have found very creative ways to reduce weight, improve ergonomics and increase the space required within these new vehicles. Future developments in the bus driver’s market seem to bring even more advanced features to the industry, such as advanced optimization Of weight including composite technologies and possibly even carbon fiber components. “
Infinity and beyond
Mirabile said that upon exiting APTA EXPO 2021, he heard almost universal excitement from OEMs and customer agencies.
“There is a high level of excitement among manufacturers as we emerge from the COVID-19 low,” he said. “They are excited to see supplier partners like us coming to the table with new products, especially products that align with their future directions.”