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
Ah, down to the two multipliers of entities without end. :B
The liberal scientific method requires us to accept the simplest possible explanation that covers all the bases. The ghost of Sir William of Occam stands guard with a cudgel in hand for those who would violate this principle.
Tluxon,
Science does not care for legalese. I believe that the hitch projects the pivot point, as indeed it must in order for the linkage to lock up. I believe that this does in fact limit sway, and therefore the document is technically correct. How it does it seems to be missing from the patent application as it frequently is, and Hensley has recently granted us access to this information, illustrating it liberally, and telling us exactly how it does it. It is now up to us to accept it or come up with a better idea. I accept it.
Ron,
I do know the answer, and you are right, I am not telling. I am not telling because it has no bearing on how the Hensley works. There are no forces acting on the hitch that are not applied straight line through the struts. The hitch pivots left and right freely from the TV end, and not at all from the TT end.
Moving the cable left or right means nothing because in operation there exists no mechanism for such a force to be applied. You have violated scientific method by positing something that does not exist and demanding an explanation of what would happen if it did.
As an engineer, it should not be difficult for you to visualize the answer. If the force vector is straight back, and the hitch is locked up, moving the vector left or right would translate some of the force into a twisting moment while the remainder would still be pulling straight back.
This has nothing to do with why the hitch is locked up, because that is a function of three pivot points being aligned, two made of steel and one virtual. Hensley appropriately calls this a converging linkage.
The hitch ball is another red herring. I believe what Hensley says about its function, in that it is allowed to rotate and to pivot up and down to some extent, limited by the struts, and not at all side to side, prevented by properly adjusted struts. The pattern of wear on mine indicates that this is what is happening, and the movement allowed is demonstratable by using adjusting the weight distribution jacks separately, or in concert, to position the hitch head.
Owners of the hitch know the principles of operation of the weight distribution jacks well, because this is what allows us to hitch up if the TV is tilted or off plane in relation to the TT. You might also note that most of us recommend that the purchaser also buy a Tongue Twister. The reason for this is that the hitch head moves not at all side to side.
One more thing needs to be said. This thread is about the Hensley Arrow hitch and how it works. It is well known, and accepted almost universally, that the Hensley Arrow prevents sway. It makes sense to discuss the hitch alone because the hitch is the only difference between a trailer that can sway and a trailer that cannot.
It makes no sense at all to make statements to the effect that the Hensley Arrow prevents sway by working in concert with numerous items that existed before the Hensley was installed. If the only difference in the equation is the Hensley, it is the Hensley that makes the difference.
The liberal scientific method requires us to accept the simplest possible explanation that covers all the bases. The ghost of Sir William of Occam stands guard with a cudgel in hand for those who would violate this principle.
Tluxon,
Science does not care for legalese. I believe that the hitch projects the pivot point, as indeed it must in order for the linkage to lock up. I believe that this does in fact limit sway, and therefore the document is technically correct. How it does it seems to be missing from the patent application as it frequently is, and Hensley has recently granted us access to this information, illustrating it liberally, and telling us exactly how it does it. It is now up to us to accept it or come up with a better idea. I accept it.
Ron,
I do know the answer, and you are right, I am not telling. I am not telling because it has no bearing on how the Hensley works. There are no forces acting on the hitch that are not applied straight line through the struts. The hitch pivots left and right freely from the TV end, and not at all from the TT end.
Moving the cable left or right means nothing because in operation there exists no mechanism for such a force to be applied. You have violated scientific method by positing something that does not exist and demanding an explanation of what would happen if it did.
As an engineer, it should not be difficult for you to visualize the answer. If the force vector is straight back, and the hitch is locked up, moving the vector left or right would translate some of the force into a twisting moment while the remainder would still be pulling straight back.
This has nothing to do with why the hitch is locked up, because that is a function of three pivot points being aligned, two made of steel and one virtual. Hensley appropriately calls this a converging linkage.
The hitch ball is another red herring. I believe what Hensley says about its function, in that it is allowed to rotate and to pivot up and down to some extent, limited by the struts, and not at all side to side, prevented by properly adjusted struts. The pattern of wear on mine indicates that this is what is happening, and the movement allowed is demonstratable by using adjusting the weight distribution jacks separately, or in concert, to position the hitch head.
Owners of the hitch know the principles of operation of the weight distribution jacks well, because this is what allows us to hitch up if the TV is tilted or off plane in relation to the TT. You might also note that most of us recommend that the purchaser also buy a Tongue Twister. The reason for this is that the hitch head moves not at all side to side.
One more thing needs to be said. This thread is about the Hensley Arrow hitch and how it works. It is well known, and accepted almost universally, that the Hensley Arrow prevents sway. It makes sense to discuss the hitch alone because the hitch is the only difference between a trailer that can sway and a trailer that cannot.
It makes no sense at all to make statements to the effect that the Hensley Arrow prevents sway by working in concert with numerous items that existed before the Hensley was installed. If the only difference in the equation is the Hensley, it is the Hensley that makes the difference.
