Hensley Arrow: How does it REALLY work?

Ron Gratz wrote:

Stressor wrote:
Can you tell me how this explanation differs in any way from this one?

Stressor wrote:






Just curious. :B

Milt,

You stated, "At any point along the lines A-C and A-B a set of points could be added as shown by D and E. These could be made flexible and become pivot points."

In my explanation, the extended links are A-C and B-E. There are no intermediate pivot points at D and E. The system A-C-B-A forms a rigid triangle -- the "A-frame" as I referred to it.

In your system, D-C-E-D forms a rigid triangle, but the 4-bar linkage A-D-E-B-A still allows A-B to translate and rotate relative to D-E.

In your second diagram, point C is the Virtual Pivot Point if the lines A-D-C and B-E-C are straight.

In your third diagram, point C is not the VPP. The VPP lies at the intersection of one straight line projected through A and D and another straight line projected through B and E. In your diagram, the VPP would lie to the left and rear of point C.

The location of the HA's VPP changes as the angle between TT and TV (same as the angle between D-E and A-B) changes. That's what makes the Hensley Arrow different from the PullRite. When the HA and PR are aligned straight ahead, the only significant difference in how they handle lateral loads from the TT is in how close their respective virtual or actual pivot point is to the TV's rear axle.

Ron

The drawing demonstrates a locked up rocker-rocker 4 bar linkage, as it is from forces delivered from the travel trailer, and the last drawing shows it unlocked during a turn. C is of course, the VPP when towing straight ahead, after all, it is a projection of the linkage as drawn. I think that makes it equivalent myself.

When turning, the pivot point, or VPP, must necessarily move towards the hitch. Didn't you say for sharp turns it actually moves very close to the actual hitch? Within about 4 inches or less because of the length of the links"