Hensley Arrow: How does it REALLY work?

Stressor wrote:
The links you are requesting have long been posted in this thread.

Milt, there is no link posted anywhere in this thread which supports your claim that the "Rocker/Rocker 4 bar linkage theory predicts the lock". If there were, I'm sure you could tell us which one.

Supporting diagrams have been posted in this thread.

The numerous flaws in your "supporting diagrams" and your explanations of same have been thoroughly discussed here and here. The diagrams only support the premise that the person who presented them has a serious lack of understanding about how the HA's linkage works.

The forces applied are determined by the attachment points of the struts.

Milt, are you aware there is a ball coupler on your trailer? Are you aware that forces are applied via both struts and the ball coupler and not just via one strut as you did in your "demonstration"? The struts only serve to prevent the TT from pivoting on the ball. A proper free body analysis of the interaction between TT and hitch assumes there is no pivoting and the forces in the struts do not enter into the analysis.

"Changing the angle" is a red herring, and has no relevance in anything other than a Ron Gratz imaginary hitch. It always was a red herring.

Milt, given this statement and the errors in your "supporting diagrams", I'm afraid the other readers will think you have no idea whatsoever of how forces are transferred between TT and TV via the HA linkages. No, the angle of force is not a red herring; it is the central issue in the "lock up" discussion.

There is only one angle to concern yourself with on a real hitch, there ain't no magic angle except on a Ron Gratz imaginary hitch.

Milt, you still have not revealed what this "one angle" is. I can think of four -- the angle of the force vector produced at the left strut pin, the angle of the force vector produced at the right strut pin, the angle of the force vector produced at the ball coupler, and, most importantly, the the angle of the vector resulting from the combination of the first three. It appears that you have no idea of how these forces are handled by the upper (rear) unit of the HA.

But in answer to your unnecessary question, changing the angle only changes the force vector, it does not unlock the hitch.

Milt, I have to agree with you on this one. Changing the angle does change the force vector, because a force vector is defined by its magnitude and direction. And, changing the angle does not "unlock" the hitch, because it never is locked in the first place.


How about the answers to my other questions:

For the test condition depicted in your photo, what was the horizontal angle between the cable and the TV's longitudinal axis?

Did you change the angle of the pull?
Did you pull, say, 10 degrees to the left and 10 degrees to the right of the angle shown?
Do you have photos to show the cable pulling at other angles?
I guess we know the answers to these last three questions since you consider the angle of the force vector to be a red herring; that is, other than that one "fortutious" angle which you claim proves your "lock up" theory.


The HA does not "lock up".
The HA does not prevent the trailer from swinging.
Lateral forces on the TT's tires control the swinging.
The HA works by reducing the magnitude of lateral force and by moving the effective point of application closer to the TV's rear axle. This significantly reduces the ability of the TT to "steer" the TV.
This, alone, is sufficient to explain the HA's anti-sway capabilities.