Hensley Arrow: How does it REALLY work?
There have been several discussions on this hitch that have become somewhat 'controversial'. I am NOT trying to stir this controversy/bashing back up. Instead, I'd like to see a good, intelligent di...
Forum Discussion
Sorry about the K Tim, I am getting nearsighted in my old age. I am glad you think you have figured it out.
A good explanation has to make sense to the person that it is presented to, has to explain that which is easily and directly observable, and it has to apply to what is being explained under real world conditions.
I believe that I have a perfect understanding of the way that the linkage works, derived through manipulation of it from both the travel trailer end and the tow vehicle end, and through observation of the hitch in use.
Isolating the hitch to observe its operation is easily accomplished by either suspending it from the travel trailer as it is normally, or by suspending it from the hitch bar for manipulation of the linkage from the travel trailer end.
I have the same reservations about your understanding as you do about mine.
Here is what I do know:
The travel trailer end of the hitch does not move relative to the trailer tongue.
The Tow vehicle end of the hitch does not move relative to the centerline of the tow vehicle.
(If you think that either of these things occurs, drop the popsicle sticks, and go play with the hitch.)
All angular change between the two vehicles is through the two links, with the forward two pivots being slightly closer together than the rear two pivots.
This geometry allows the tow vehicle to change direction, collapsing one link inward to do so, and therefore the trailer turns with it.
The same geometry does not allow the travel trailer to turn the tow vehicle. The link will not collapse from the travel trailer end of the hitch. Any forces transferred through the linkage are therefore applied as a sideways force to the tow vehicle at the location of the VPP.
The tow vehicle resists this force due to a number of factors including traction, moment, and plain old dead weight to name but a few. So does the travel trailer, and the good news is, since the trailer continues to track directly behind the tow vehicle, there is no sway.
This is a perfectly good mechanical explanation, and it has the benefit of being easily observable, easily demonstrated, and it explains the behavior of the travel trailer in combination with the tow vehicle.
What did I miss?
A good explanation has to make sense to the person that it is presented to, has to explain that which is easily and directly observable, and it has to apply to what is being explained under real world conditions.
I believe that I have a perfect understanding of the way that the linkage works, derived through manipulation of it from both the travel trailer end and the tow vehicle end, and through observation of the hitch in use.
Isolating the hitch to observe its operation is easily accomplished by either suspending it from the travel trailer as it is normally, or by suspending it from the hitch bar for manipulation of the linkage from the travel trailer end.
I have the same reservations about your understanding as you do about mine.
Here is what I do know:
The travel trailer end of the hitch does not move relative to the trailer tongue.
The Tow vehicle end of the hitch does not move relative to the centerline of the tow vehicle.
(If you think that either of these things occurs, drop the popsicle sticks, and go play with the hitch.)
All angular change between the two vehicles is through the two links, with the forward two pivots being slightly closer together than the rear two pivots.
This geometry allows the tow vehicle to change direction, collapsing one link inward to do so, and therefore the trailer turns with it.
The same geometry does not allow the travel trailer to turn the tow vehicle. The link will not collapse from the travel trailer end of the hitch. Any forces transferred through the linkage are therefore applied as a sideways force to the tow vehicle at the location of the VPP.
The tow vehicle resists this force due to a number of factors including traction, moment, and plain old dead weight to name but a few. So does the travel trailer, and the good news is, since the trailer continues to track directly behind the tow vehicle, there is no sway.
This is a perfectly good mechanical explanation, and it has the benefit of being easily observable, easily demonstrated, and it explains the behavior of the travel trailer in combination with the tow vehicle.
What did I miss?
