Accessibility Modifications to a Ford 4000 Tractor for a Farmer with a Spinal Cord InjuryBy Wray, Christopher L.; Downs, H. Willard; Borgelt, Steven C.; Funkenbusch, Karen; Agrability Quarterly,
Publication Date: July/August 2001
Article discussing a Missouri AgrAbility project to modify a Ford 4000 tractor to accommodate a farmer with a spinal cord injury. Additions were made to update the tractor and make it safer to operate. A Roll Over Protection System (ROPS) donated by Saf-T Cab was installed. A power take-off shield was also designed and installed on the tractor. While the tractor could be accessed from either side, the lift was installed on the left side of the tractor to avoid the brakes and the hydraulic controls on the right side. The left rear tire and the fender were moved out to provide more space for the lift. The tire was moved out using the spinouts on the hub and effectively widened the wheelbase, allowing the fender to be mounted further out. The actual chair moved up and down a beam, and was attached to a chain that was powered by a gear-motor. A carriage that would roll up and down the I-beam with the seat attached was designed, and a plastic boat seat with removable vinyl cushions was used for the transfer seat. The seat required a flat base to be mounted, and included a swivel mechanism that allowed the seat to be locked into a fixed position. A 1 horsepower DC motor with an attached right angle 40-I worm gear drive was donated by DW Auto. A 13 tooth idler gear and a bracket at the lower end of the I-beam were designed to allow tension and adjustment of the chain, and a skid-plate/guard was attached to protect the sprocket and chain from damage. A set of hand controls were designed to operate the brakes and meet the design criteria. Two levers were designed and fabricated from 0.5-inch solid square bar shock to extend from the individual brake pedals to a position where the client could easily reach for operation. A hand clutch lever was designed with linkages and a spring that would pull over-center. The clutch pedal required 30 degrees of rotation for full disengagement. The increased degree improved the feel of the clutch by helping it to feel less sensitive. The lift was approved following tests for durability and function.
University of Wisconsin - Madison (Web Site: http://www.wisc.edu )
Link to text: http://www.agrabilityproject.org/assistivetech/tips/modifyingford4000.cfm