Ron Gratz
full time RVer
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Hensley Website wrote:The secret of the Hensley Arrow rests in its patented converging linkage design. The Arrow allows movement on the ball in every direction except side-to-side. Milt, you have misread a key word. It says, "movement on the ball". It does not say, "movement of the ball". Other movement on the ball which is not allowed is: front-to-rear, up-and-down, and rotation in a horizontal plane (due to the struts).
Hensley Website wrote:Side-to-side movement is forced to go through the linkage system which is one directional.
I interpret the phrase, "side-to-side movement" to mean that something is moving side-to-side. Since they are talking about the linkage, they obviously are referring to the side-to-side movement of the HA's upper (rear) unit relative to its lower (front) unit.
Hensley Website wrote:From the trailer side, the linkage is solid. Pivoting by the linkage must be initiated through the tow vehicle.
Pivoting by the linkage can be initiated from either end. If the convergence of the side links were reversed, you still could steer the TT with the TV. Of course, it would handle differently because the VPP would be to the rear of the hitch instead of forward.
Stressor wrote:This says what I have been saying, and I have provided an illustrated explanation of how a converging linkage works in this thread.
"Side-to-side movement is forced to go through the linkage system which is one directional. From the trailer side, the linkage is solid."
I am always happy to be quoted by a manufacturer.
That is not what you have been saying. You have been saying the ball cannot move side to side and you attempted to prove it with your photos and diagrams. The ball does move side-to-side relative to the front of the hitch and a properly conducted "demonstration" would clearly show it. You were not quoted by a manufacturer. You are quoting them -- simply parroting their marketing hype.
Milt, if you want to cite from Hensley literature accurately describes how the HA really works, I suggest you refer to the Hensley Patent Document. It provides a description which has a sound physical basis. The Hensley marketing materials do not. Unfortunately, in the Patent Document, you'll not find any discussion of terms such as "locked", "one directional", straight truck", etc. And, please, don't respond to this suggestion with your Patent Lawyers argument. I'd hate to have to go through all of that again.
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.
* This post was
edited 08/26/05 02:10pm by Ron Gratz *
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tluxon
Kirkland, WA
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Joined: 08/12/2001
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Thanks a lot, you guys! I go away for 10 days and come back to find 47 new posts in this thread that only show that you're starting over! ![[emoticon]](http://www.coastresorts.com/sharedcontent/cfb/images/eek.gif "eek") ![[emoticon]](http://www.coastresorts.com/sharedcontent/cfb/images/awink.gif "awink")
I suggest that if you are really that curious as to why a couple non-Hensley owner engineers (Ron and I) are not giving in to the concept of the Hensley ever being a "locked" hinge hitch - you should try to contact someone at Hensley who might (I'm sure they have more valuable things to do) take an official position on the topic (the piece that Milt quoted from the Hensley website doesn't count because it was misinterpreted).
The problem that has been missed by some of you is whether or not any of the 4 pins in this 4-bar linkage are fixed. As long as they are not and are not restricted from pivoting by anything other than the linkage itself, the only "locking" that CAN occur is outside of the linkage, e.g., the frictional contact that any of the involved vehicles' tires have on the ground that prevents the angulation (trans-rotation) that the linkage is forced to go through in order to pivot. This does NOT mean the linkage itself locks, but it does make the linkage ACT like it's locked in most applications.
BTW Will, the "tug" that that TV places on the TT does relatively little to resist the trans-rotation of the hitch in comparison to the trailer tires not sliding side-to-side laterally in a manner that accomodates angulations that would be forced by the linkage in order to pivot.
I thought we covered this back in June. ???
Tim
Tim -
wife Beverly & 2 boys who love camping
2002 K2500 Suburban 8.1L 4.10 Prodigy
2005 Sunnybrook 30FKS HP Dual Cam
Replaced 2000 Sunnybrook 26FK on 8/6/04
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drfife
Dallas, Texas, USA
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Joined: 11/02/2002
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Tim:
Have you considered that the linear vector force of the tow vehicle on the hitch while in forward motion increases the amount of force necessary to obtain lateral movement of the linkage?
This force may essentially "lock up" the linkage from lateral forces unless they exceed the forces that are incurred by the forward motion of the tow vehicle.
Which would be a LOT of force.
I'm not an engineer, and I don't play one on TV.
Just thought I'd throw that out for you and Ron to dissect....
Russell
'12 GMC Sierra 3500HD SRW
'13 Excel Winslow 34IKE
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tluxon
Kirkland, WA
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drfife wrote:Have you considered that the linear vector force of the tow vehicle on the hitch while in forward motion increases the amount of force necessary to obtain lateral movement of the linkage? Absolutely, it increases the force needed, but not enough by itself to stop a trans-rotation.
drfife wrote:This force may essentially "lock up" the linkage from lateral forces unless they exceed the forces that are incurred by the forward motion of the tow vehicle. It contributes, but the real force that "locks up" the linkage is the fact that the solid connection of the rear linkage bar to the trailer via the two struts requires that the trailer would somehow rotate in the OPPOSITE direction of the moment that initiated any lateral movement in the first place.
To help illustrate my point, in this post, I included the following figure.
![[image]](http://home.comcast.net/~tbluxon/Hensley_Fig4.jpg)
In application, a trailer would need a counterclockwise (CCW) moment in order to move the rear bar to the left as shown. However, the linkage will NOT move unless the trailer is angulated in a CLOCKwise direction. This makes trans-rotation impossible from a moment about the trailer's axles. Using this model, the only way trans-rotation could take place is if a moment initiates about the virtual pivot point, which really can't happen as long as the TT's tires have lateral friction.
I think we're on the same page using different terminology.
Tim
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BurbMan
Indianapolis, IN
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Joined: 09/20/2001
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tluxon wrote:This does NOT mean the linkage itself locks, but it does make the linkage ACT like it's locked in most applications.
Tim, welcome back! Yes, thanks to Will we have resurrected this thread...anyway, I'm glad you to took the time to chime in. Your quote above is EXACTLY what Milt, Will and I have been trying to point out. In fact, Russ has brought up the same point about the force exerted by the forward velocity of the TV that Will and I were tossing around last week while you were on vacation.
Anyway, the discussion continues as we try to resolve the subjective area between the theoretical and the practical, which is why I selected the above text from your previous post.
What we HA owners are saying is that it doesn't matter if the linkage CAN move, the fact is that it DOESN'T move for the reasons you point out. Unfortunately, Ron has an excellent grasp of the math and physics that drive this design, but he refuses to acknowledge this point, and so the discussion continues.
Don
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willald
NC
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tluxon wrote:It contributes, but the real force that "locks up" the linkage is the fact that the solid connection of the rear linkage bar to the trailer via the two struts requires that the trailer would somehow rotate in the OPPOSITE direction of the moment that initiated any lateral movement in the first place.
To help illustrate my point, in this post, I included the following figure.................In application, a trailer would need a counterclockwise (CCW) moment in order to move the rear bar to the left as shown. However, the linkage will NOT move unless the trailer is angulated in a CLOCKwise direction. This makes trans-rotation impossible from a moment about the trailer's axles. Using this model, the only way trans-rotation could take place is if a moment initiates about the virtual pivot point, which really can't happen as long as the TT's tires have lateral friction.
I think we're on the same page using different terminology.
That could well be, Tim. And, I agree 100% with your diagram, and your points about how the rotation works.
However, I think the point we're trying to make (and your diagram illustrates it even more), is that IN ADDITION to the point about clockwise/counter-clockwise moment you mentioned, the Hensley also makes pivoting impossible (from the trailer side) because of the fact that in order to rotate, the trailer/Hensley has to move forward slightly. And, in order to move forward, it has to overcome a LOT of force, when being pulled on. Look at your diagram, and notice how when it shows a swing to the left, the bar has moved forward a good ways. This illustrates the point we've been trying to make. Thanks for providing this illustration, that proves what we were trying to say. ![[emoticon]](http://www.coastresorts.com/sharedcontent/cfb/images/smile.gif "smile")
Like I said before - picture a pendulum, where as the pendulum swings to either side, a mechanical linkage also shortens the arm. Thats similar to what we have here.
BTW, we just got back from a GREAT camping trip, with some of our good camping friends ('JALCamper' here on the forum). Had a great time, weather was perfect, was one of the most fun trips we've had in a while. We were going down the interstate yesterday on the way home, doing a good 70mph and STILL had a semi blow by us going faster than that, we felt NOTHING. Just one more reminder of how well this hitch does exactly what it was designed to do.
Will
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Stressor
Whitefish Bay, Wisconsin
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Joined: 05/29/2001
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Ah, I see now. Hensley does not know how their hitch works, they are just engaging in a conspiracy of some sort, and we cannot trust what they say in public statements on their website. The "real majick"can only be found in other documents, to which only a select few are privy.
Folie a Deux
Quote:
Folie a deux is the situation where a paranoid delusional system appears to have developed in a person as a result of a close relationship with another person who has an established and similar delusional system.
This condition is rare and is usually seen in two people who are members of the same family. Generally there is a dominant partner with fixed delusions who appears to induce similar delusions in a dependent or suggestible partner. This sometimes will occur after initial resistance. Usually the two people have lived together for a long time in close intimacy. There is often isolation from the outside world.
The delusions of the second person quickly weaken if the two are separated.
Carry on then. ![[emoticon]](http://www.coastresorts.com/sharedcontent/cfb/images/biggrin.gif "biggrin")
![[image]](http://home.ripway.com/2005-1/238631/Folder%20Name/Hensleytext006.JPG)
Milton Findley (and Kerene)
A small piece of my mind...
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willald
NC
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Geez, Milt...Just when I thought we were all about to come to a good, solid agreement on this, then you have to jump in and call everyone in this discussion (except hensley owners) 'dillusional'. Such comments aren't really helping matters, and I sure hope it doesnt make this thread go downhill, and get locked. We've come too far to let that happen...
Please, lets try to get back to what Tim, Ron, Don, and I were discussing, and avoid making posts that could be taken as insulting. Insults really don't accomplish much, except make a thread go downhill fast.
Will
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AO_hitech
SF Bay Area
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Joined: 08/09/2004
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Quoted from the patent:
This has the effect of placing the effective pivot point for the trailer ahead of the actual hitch assembly, which in turn enhances the stability of the combination tow vehicle and trailer, rendering it less susceptible to swaying or fishtailing in the presence of side winds.
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Stressor
Whitefish Bay, Wisconsin
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Delusional has only one l.
Hensley Website wrote:
The secret of the Hensley Arrow rests in its patented converging linkage design. The Arrow allows movement on the ball in every direction except side-to-side. Side-to-side movement is forced to go through the linkage system which is one directional. From the trailer side, the linkage is solid. Pivoting by the linkage must be initiated through the tow vehicle. The system's design is inherently stable. Best of all, it functions mechanically, without the use of friction so it exhibits consistent and predictable behavior regardless of changes in weather or road conditions.
If the hitch is locked up, as demonstrated below, and as stated above, there is no pivot point, because there is no pivoting going on.
As I stated before, patent documents will say just about anything to secure a patent. I know Ron says otherwise, but then, he thinks it is the traction of the rear tires that keep the trailer from swaying. Note that the rear tires are missing in the picture above, and nothing is pivoting with a loaded 4000 pound come-along attached.
Carry on.
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