Mechanical Trailer Ramps Deploy Automatically

Kenny Vandeventer’s skid steer flips its trailer ramps up or down as it drives on or off the trailer. The automation is strictly mechanical with no hydraulics, electronics or remotes involved.


   “I racked my brain for many years to figure an alternative to manhandling the ramps,” says Vandeventer. “I had the trailer in the shop one winter to pack some bearings, and the light came on.”


   Vandeventer’s solution was to take advantage of the dovetail-type ramps with their flip-over lower sections and permanently mounted uppers. He mounted a 9-in. roller chain sprocket to the side of the rear end of the trailer. A 2 1/2-in. sprocket is mounted on a 3/4-in. steel shaft at the joint of the left-hand ramps. The shaft runs through both sets of ramps and is fixed to the lower ramps. A third and smaller sprocket pulls the roller chain down from the large sprocket to run along the side of the upper ramp. It also adds tension to the chain.


   He mounted activator bars at the top of the upper ramp and about 4 ft. forward on the trailer.


   When the ramps are down, the forward bar rides about 5 in. above the bed, while the rear bar rests on the upper ramp. A length of channel iron runs from the forward bar to a bolt welded to the sprocket. A 1-in. wide steel strap connects the two activator bars.


   When the rear wheel of the skid steer backs over the forward bar, the arm moves the large sprocket about 3 in. The gear ratio translates this to a half revolution of the drive sprocket and shaft. At the same time, the activator bar on the upper ramp is raised up off the bed about 5 in. after the front wheel of the skid steer has passed over it. When the skid steer is driven off, the front wheel depresses the rear bar, which pulls the channel iron shaft forward, reversing the direction of the sprocket and roller chain and returning the forward bar to its 5-in. height.


   “If you back on fast, the lower ramp slams into place,” says Vandeventer. “Drive off fast and it slams back down.”


   Contact: FARM SHOW Followup, Kenneth Vandeventer, Ottawa, Kan.