Foldable rollover protective structures: Universal lift-assist design

• Published in: Biosystems engineering 2019-09, Vol.185, p.116-125
• Main Authors: Ayers, Paul D., Khorsandi, Farzaneh K., Poland, Matthew J., Hilliard, Cameron T.
• Format: Article
• Language: English
• Subjects: Actuation force; Folding; Handle force; Torsion spring
• ISSN: 1537-5110; 1537-5129
• DOI: 10.1016/j.biosystemseng.2019.02.014

The numbers of agricultural tractor rollover fatalities occurring with foldable rollover protective structures (FROPS) in their lowered position are significant. Raising and lowering the FROPS is a time consuming and strenuous process, and operators often leave the FROPS in the folded-down position providing no protection during a rollover. The purpose of this project is to design, manufacture, and test a lift-assist mechanism to raise and lower the FROPS from the operator's seat. The lift-assist design is based on the FROPS actuation forces, FROPS and tractor dimensions, and ergonomics engineering standards [SAE J898/ISO 6682 and SAE J1814]. The design considered can be retrofitted and will not modify or compromise the FROPS structure. A universal lift-assist lever design has been constructed and successfully tested for three FROPS of different sizes meeting appropriate ergonomics engineering standards. The operator actuation forces were less than the 75 N allowable maximum, and within the zones of comfort and reach for the operator. The lift-assist design uses an energy absorbing torsional spring to accommodate heavier FROPS designs. •A lift-assist lever that actuates the ROPS from the operator seat was designed.•The design is based on the actuation forces, dimensions, and ergonomics standards.•The designs were successfully evaluated with three ROPS of different sizes.