I'll explain. The frame rails need to be strong, especially in the center line between the axles where the joint is. To have that joint in that spot would need some seriously heavy steel in the hardware, especially when you consider twisting on uneven terrain. Also, the drive shaft runs through there. Furthermore, how does the bed slide forward with a load on it?
This joint just adds needless complexity. Ramps stowed in the back end of the truck bed are best.
exactly my thought. the drive should go to a set of wheels in the center before the trailer. the tray would still be heavy enough to tilt the whole thing down for the loading. it's just gonna be simpler this way, the rear part is then just a trailer with a slider that tips the whole thing down.
it is quite elegant but merging the drive with the tilting hinge at the centre is too far.
I just envisioned some sort of lap joint with a heavy equipment like greased metal bushing or axel like joint at the bottom of the lap & an almost equally beefy lock pin in the top part of the lap. The driveshaft would need to hinge with a universal joint in the same plane as the frame hinge, possibly at the end of a remote mounted transfer case. A winch or hydraulics would slide the bed, but having the bed move on a single plane seems like less complication & a better failure mode when compaired to modern rollbacks.
Needing a shorter area to fit a truck in front of or behind a car & having a shallower slope when putting the car on the truck are valuable things, ramps are generally bad for both.
It's possible that it wouldn't work as well as I think, but it's definitely creative & interesting. Maybe just a solid frame with a properly designed air suspension that could drop the back & raise the front, squatting the truck on command, plus a sliding bed or ramps would work & be simpler 🤔 idk
While the bed on a rollback has multiple fail points because it has all that movement….you can still drive the truck if the ramp fails (unless it fails on the ground of course). If your hydraulics failed on this thing, would it still be able to drive? I don’t know. It’s definitely different, but having driven a rollback, I’ll stick with a rollback lol
