Isolating vibration and noise to minimize their adverse impact on the operator is often extended to the operator’s seat. Industrial equipment designed for heavy surface mining, construction, and agriculture applications usually includes at least a basic passive suspension seat comprising a damper and some form of spring. Additional ergonomic options for the seat could include orthopedically designed cushioning, lumbar support, air or other special types of suspension, swivel, and the ability to adjust to multiple positions to suit operator size and preference.
In tests on six types of suspension seats, National Institute of Safety and Health found that the isolation of vibration provided by a passive suspension seat incorporating linear extension, air, or other types of springs could be further improved with the application of rheology. Lord has integrated magnetorheological (MR) technology into its Motion Master suspension system in the form of a damper filled with fluid that changes viscosity when exposed to a magnetic field. Based on real-time data such as operator body weight and changing levels of shock and load vibration, the system adjusts the strength of the magnetic field to induce the appropriate level of viscosity, thus providing variable compensation ranging from soft to stiff, depending on conditions. Lord’s MR-based seat technology is part of Sears Seating’s semi-active suspension, which is available in seats for agricultural, mining, and construction equipment.
In addition to isolating the noise and vibrations generated during normal equipment operation, seats may also incorporate stabilizers to help absorb vibrations and jolts in the direction of travel, as well as perpendicular to the travel direction.
Manufacturers have continued to upgrade operator seat ergonomics. Grammer, for example, has developed an active seat climate system incorporating a layer of activated charcoal just below the seat’s outer fabric that absorbs body heat and perspiration to cool the driver at the point of contact between driver and seat. Cool, dry air passing through a ventilation layer removes moisture from the charcoal and cools off the outer seat surface.
The seat climate system can also be equipped to provide heating for cold-weather operations. Grammer incorporates its active seat climate control technology into its Maximo Evolution seats for large tractors; these seats also feature a low-frequency suspension system for attenuation of acceleration, and dynamic electronic adjustment based on the operator’s weight.
Operator seats can also incorporate multifunctional joystick controls. With its Turnabout console, CNH tailored its seat to accommodate multiple applications by incorporating the seat, throttle, instrumentation, and implement management into a single rotating unit that can be positioned to face either end of the vehicle. A knobbed steering wheel at the operator’s left and peripheral controls at the operator’s right travel with the console as it rotates through a range from 0 to 240°. In addition to standard positions, the console can also be set at a 15° offset from each position.