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Chip Petrea's Forklift-Style Platform Lift
Chip Petrea's Forklift-Style Platform Lift
Chip Petrea's Forklift-Style Platform Lift
Chip Petrea's Forklift-Style Platform Lift
Two photos showing the tractor and bolted-on lift with its component parts as described.

Chip Petrea's Forklift-Style Platform Lift (built by the Braun Corporation of Winamac, IN) enables the Iuka, IL, farmer to gain access to the operator's station of his International Harvester 186 Hydrostatic tractor. He rides the lift standing up; however, it could be adapted for one in a wheelchair if the platform were enlarged. Although not commercially available, the lift is discussed here because of its many workable concepts and the following desirable safety features—(a) a 12-volt electro-hydraulic system that allows lift operation without the tractor running, (b) multiple control locations (i.e., at ground level, at the operator's station, and on the lift platform), and (c) controlled descent should the hydraulics fail. The hydraulic system utilizes one single-acting cylinder to raise the lift platform like a forklift. The lift does not prevent others from using the tractor because the cab steps and a door are on the opposite side. To improve accessibility for Petrea, the lift-side cab door hinges were reversed so that the door opened toward the rear of the tractor; and the main shifting lever was repositioned so it would not interfere with his reaching the tractor seat. Also, the lift was designed to be easily removed if the tractor needs servicing. The lift's mounting frame reaches over the top of the engine compartment and is bolted to both sides of the tractor frame to provide support during tractor operation on rough terrain. The lift guide, welded to the mounting frame, consists of two vertical steel tubes coated inside with low-friction material to eliminate the need for greasing. An expanded-steel operator's platform has plates welded on the sides closest to the tractor and its front wheel to ensure that Petrea's feet won't slide off. Waist-height hand grips on the front and left sides of the platform hold a weatherproof switch that operates the lift and a bracket for Petrea to hang his crutches on while operating the tractor. Two slide tubes with roller chains fastened to their tops reach up from two lift platform corners and slide inside the guide tubes, so the platform travels straight up and down without swaying. The chains attached to the slide tubes (a) travel through the guide tubes to the top of the mounting frame, (b) pass over sprockets and run horizontally to the edge of the mounting frame, (c) pass over more sprockets and down the outside of the frame, (d) roll around sprockets on the rod of a hydraulic cylinder that's mounted vertically to the bottom of the mounting frame, and finally (e) travel back up to fasten solidly near the top of the mounting frame. As the cylinder retracts, the chains pull the slide tubes up through the guide tubes to raise the platform. A bypass valve prevents damage to the hydraulic pump if the switch is not released; and a manual reset breaker protects the tractor's power system from overloads. An extension on the tractor's operator platform allows Petrea to walk from the lift to the tractor cab. A pressure-compensated, flow-control valve installed in the hydraulic system controls the rate of descent, based on how much weight the platform is carrying. Allowing gravity to lower the lift reduces battery drain and eliminates 50% of the cycle wear time on the hydraulic pump.

Estimated Cost Cost range: See below

Limitations Limitations Addressed by Product: Lower extremity


SourceChip Petrea
Iuka, IL, 62847

SourceBraunAbility
631 West 11th Street
Winamac, IN, 46996
Websitewww.braunability.com
EmailWeb form
Phone800-488-0359
Last updated: Apr 14, 2017


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