Parking Swivel

My husband collects cars.  He is fanatical about not starting them unless they are going to be driven.  “Condensation collects in and corrodes the exhaust system unless they are brought up to full temperature,” he says.  So, he often uses a hydraulic floor jack under the rear of the car to move the cars around in the garage.  It’s amazing how adept he has gotten at gliding the cars around--getting them in and out of tight spots--just using that floor jack.  Watching him do this tonight got me to thinking . . . .

How nice it would be if my (non-collectable) car was equipped with a small, heavy-duty 5th wheel that descended and picked up the back end of the car just enough to allow the rear of the car to be moved laterally on the 5th wheel.  The small, hard-rubber adorned, wheel would caster and the transaxle would supply directional impetus through the front wheels by channeling power precisely, differentially, to each wheel based on input from the steering wheel.  Turn the steering wheel slightly left and the back of the car swings to the right, and vice versa.  The further the steering wheel is turned, the tighter the arc, until some limit, perhaps the caster limit of the 5th wheel, is reached.  One wheel would have to roll forwards and the other backwards to do very tight turns and slightly wider sweeps would only need one wheel to roll while the other is stoutly held stationary.  The throttle would be managed by the power system (as it is when traction control engages), so that the rate of turn is safe and slow.  With this arrangement, I could navigate in and out of very tight spots by pirouetting on the front wheels to orient the car and then retracting the 5th wheel and moving into the spot normally.  This system would only work on front-wheel drive cars, of course.

There are a few patents covering systems similar to this but none of them use differential power to the drive wheels to effect the lateral motion (as far as my searches revealed).  No mercy votes, please.  If you think this is baked . . . 'bone it.