As vehicle operators continue to spend more time in their machines, choosing a comfortable seat is becoming just as important to an OEM’s design process as choosing the right gauges or displays. To help OEMs continue to provide the best seat for equipment operators, seat companies are constantly developing new seats to meet changing operator comfort needs.
Ron Mock, Director of Market Intelligence at Sears Mfg. Co. (Sears), says the company is designing new things all the time. From large projects designing new cushion technology to smaller redesigns such as making wider and longer armrests, the company is always working on ways to keep operators comfortable.
One of the biggest factors affecting operator comfort is the combination of noise, vibration and harshness (NVH) caused by the various systems used in mobile off-road equipment and the terrain those vehicles drive over. Seat manufacturers attempt to combat NVH in a number of ways, one of them being the suspension system built into the seat.
Two commonly used suspension systems in seat design are mechanical and pneumatic suspension. Mechanical suspensions use coil springs as well as energy-damping shock absorbers to provide a smooth ride similar to that of a passenger car. Meanwhile pneumatic suspension systems employ air springs which have a variable spring rate.
Active air and semi-active air suspension systems are two of the pneumatic offerings from Sears. Designed with John Deere and Co., the active suspension uses the tractor’s hydraulics to help alleviate vibrations. Speed sensitivity was built into the suspension system as well, so no matter how fast or slow the vehicle is going, the suspension system will keep the operator comfortable.
The semi-active suspension, according to Mock, is an electromagnetic damping system. An electronic controller sends a variable electric signal to the semi-active shock absorber as the suspension system travels up or down. This electric signal causes the shock absorber to create a softer or firmer ride dependent upon vibration inputs.
Sears now has a heavy-duty version of its semi-active suspension called the VRS 3. Designed for vehicles with extreme ride and vibration characteristics, the suspension has a 3 in. longer stroke, which “gives us a better isolation of vibration” says Mock. Stroke refers to the travel of a suspension system, such as up and down.
Along with suspension systems, seat manufacturers offer a number of comfort features to ensure a more pleasant seating experience. Add-ons such as adjustable armrests, headrests, cushion heaters or height-adjustable seat risers provide vehicle operators with more comfort for their long workdays.
David Winkels, Senior Vice President, and Brent Clark, OEM Sales Director at the Seating Solutions division of Iowa Export-Import/Global Solutions (IEI) say the company is continually working to update its seats and seat options to enhance operator comfort. This is why the company not only offers components such as adjustable armrests or lumbar support as add-on options but as standard features, as well. Seats like IEI’s premium high back seat have models which come standard with adjustable armrests, adjustable lumbar support, seat contouring and a taller seat back, which provides support without restricting the user’s vision while operating the vehicle.
For its full adjustment seat with suspension, IEI includes a seat back that can be adjusted backward 28 degrees and forward 90 degrees. Weight adjustment and three position height adjustment are also included as part of the seat’s comfort features. Since a vehicle can often have a different user every day, adjustable components such as these allow users to tailor the seat to their individual comfort needs.
The importance of system optimization as well as individual component optimization.