INCREASED INDEPENDENCE FOR FARMERS WITH A PHYSICAL DISABILITY
D. Keith Morris Agricultural and Biological Engineering Department, Purdue University, West Lafayette, IN U.S.A.
ABSTRACT
When faced with the reality of a physical disability many farmers see accessing the tractor or combine as an obstacle to their returning to their farming operation, especially when the farmer is limited in his or her climbing ability due to a mobility impairment. The Pilot Lift, a vertical screw chair-lift, was first conceived when a farmer with a disability in Vermont approached the Agricultural Engineering Department at a midwest university to develop a chair-lift to access his tractor. A prototype was developed and tested, and Round Grove Machine Inc. was approached about the feasibility of commercially developing a quick, reliable, quality-built product that would allow a farmer to continue his or her farming operation after a disabling accident or illness.
INTRODUCTION
The National Safety Council has ranked agriculture as one of the most dangerous professions in the United States. Data from 1994 university studies indicate that approximately 140,000 disabling injuries occur each year to American farmers. Studies indicate that the total population of farmers/ranchers with spinal cord injuries in the United States is estimated to be between 4500 and 6500 with approximately 250-300 new spinal cord injuries occurring each year. When faced with the reality of a physical disability many farmers see accessing the tractor or combine as an obstacle to their returning to their farming operation, especially when the farmer is limited in his or her climbing ability due to a mobility impairment. Many times farmers design and fabricate their own chair-lifts; most are functional but are not suited for universal commercial applications. The need for a chair-lift which is low maintenance, easy to access and operate, and most importantly dependable is foremost in the minds of farmers with physical disabilities.
DESIGN AND DEVELOPMENT
Initial studies of the problem indicated that there was a need for a chairlift attachment for tractors and combines that would provide the following: 1. A seat or platform that would lift the operator from the ground to a position that would enable him/her to transfer into the operator's seat. 2. Easy installation on the tractor or combine with the least amount of alterations to the original equipment and minimum interference with the operator's vision. 3. A design that was powered by the electrical system of the tractor and did not depend on the operating engine for operation. 4. A lift speed of approximately 5 feet/min and a lifting capacity of at least 300 pounds. 5. Fail-safe lift operation that would protect the operator in the event of power or drive mechanism failure. During the 1980's, a variety of prototype lifts were developed and tested by C.B. Richey at a midwest university. Several concepts were examined, including a vertical winch-lift with a slide through seat, vertical lift platforms operated by winch and cable or by hydraulics, parallel linkage lift, a seat mounted on inclined rails raised by a winch and cable, and a vertical screw lift. The vertical screw lift has proven to be the most adaptive to the greatest number of applications. In 1987, Hubert Von Holten owner/operator of Round Grove Machine Inc. in West Lafayette, IN decided to commercially develop a reliable, quality-built chairlift that would allow a farmer to continue his or her farming operation after a disabling accident or illness. To date, approximately 150 of these units (Pilot Lift) have been installed on agricultural tractors and combines. Variations of the Pilot Lift have also been used in other agricultural and recreational applications.
The original proto-type of the Pilot Lift underwent several minor and major design changes as Von Holten gained experience in producing the lifts and working closely with agricultural clientele. The most significant of these design changes was the introduction of two more electric motors located at each end of the swing arm which allow the swing arm to pivot 3600 around the mounting unit (Figure 1). Other changes include the addition of a bellows around the screw to eliminate dust and dirt from affecting screw operation and the attachment of the seat from a suspended pole which allows the lift seat to be placed within easy transfer distance of the operator's seat on the tractor or combine. The Pilot Lift is operated by a six button (3 pairs) umbilical control box. Each pair of buttons controls one of the three motors. Two of the motors are located on the swing arm and the other motor is located at the top of the screw jack. The motors are all 1/4 hp 12 volt reversible DC electric motors. The mast and screw are custom cut to any specified length depending on the application.
Figure 1
The Pilot Lift will continue to change as the needs of farmers/ranchers with physical disabilities continue to change. Each unit is custom-designed to the individuals' tractor or combine to provide easy access and an increased independence for farmers with a disability.
REFERENCES
1. Bowles, Jerry W., and Field, W.E., Plowshares #8: New Concepts in Manlifts for Farmers and Ranchers with Physical Handicaps. Breaking New Ground Resource Center, 1990.
2. Wilkinson, T.L., and Field, W.E., Modified Agricultural Equipment: Manlifts for Farmers and Ranchers with Physical Handicaps. Breaking New Ground Resource Center, 1987.
ACKNOWLEDGMENTS
Breaking New Ground Resource Center Agricultural and Biological Engineering Depart. Purdue University West Lafayette, Indiana. 47907-1146
Round Grove Machine Inc. 345 Burnett Road West Lafayette, Indiana. 47906 (317) 423-4192