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
Milt,
I see your picture as showing longitudinal force; it seems to me the forces that are most likely to be present in sway are lateral forces, which Ron has stated several times. You are correct in that the HA won't move with the type of force on it that your picture shows, it'll break before it moves, however it isn’t locked. I think that you are also correct in your assertion that simply pulling your HA mounted TT down the road assists some in the HA's stability, because as the HA moves through its range, the TT must move closer to the TV.
I particularly like Tim’s terminology describing the HA’s motion as trans-rotational, because it must rotate as it translates through it’s motion, also note that the rotational direction is opposite that which would allow sway. I also believe that Ron is correct in his assertion that the HA gets some of it’s stability by putting the lateral forces on the TT tires.
Imagine the following scenario…
You are driving along in the right lane of a 2 lane highway, pulling your HA mounted TT. A large truck passes you in the left lane. As the bow wave from the truck pushes the back of your TT to the right, it causes a CCW pivoting action about your TT’s axles. This in turn causes the front of the TT to attempt to swing to the left. As your HA moves to the left it has to rotate CW, because of the linkage. This CW rotation then loads the RH strut on the HA, which prevents any pivoting about the ball, and effectively ends the sway moment, unless the lateral forces that are put on the TT tires are so great that they cause the tires to loose traction.
I believe that if you were to take your HA mounted TV/TT to a flat smooth parking lot and put swiveling dollies under each of your TT wheels you would be able to swing your TT around behind your TV rather easily, it would just be in a very controlled path.
Hopefully I’ve explained my little scenario is clearly enough for everyone to understand, if not let me know.
Dave
Edited 9/6 to clarify the scenario part of the message
I see your picture as showing longitudinal force; it seems to me the forces that are most likely to be present in sway are lateral forces, which Ron has stated several times. You are correct in that the HA won't move with the type of force on it that your picture shows, it'll break before it moves, however it isn’t locked. I think that you are also correct in your assertion that simply pulling your HA mounted TT down the road assists some in the HA's stability, because as the HA moves through its range, the TT must move closer to the TV.
I particularly like Tim’s terminology describing the HA’s motion as trans-rotational, because it must rotate as it translates through it’s motion, also note that the rotational direction is opposite that which would allow sway. I also believe that Ron is correct in his assertion that the HA gets some of it’s stability by putting the lateral forces on the TT tires.
Imagine the following scenario…
You are driving along in the right lane of a 2 lane highway, pulling your HA mounted TT. A large truck passes you in the left lane. As the bow wave from the truck pushes the back of your TT to the right, it causes a CCW pivoting action about your TT’s axles. This in turn causes the front of the TT to attempt to swing to the left. As your HA moves to the left it has to rotate CW, because of the linkage. This CW rotation then loads the RH strut on the HA, which prevents any pivoting about the ball, and effectively ends the sway moment, unless the lateral forces that are put on the TT tires are so great that they cause the tires to loose traction.
I believe that if you were to take your HA mounted TV/TT to a flat smooth parking lot and put swiveling dollies under each of your TT wheels you would be able to swing your TT around behind your TV rather easily, it would just be in a very controlled path.
Hopefully I’ve explained my little scenario is clearly enough for everyone to understand, if not let me know.
Dave
Edited 9/6 to clarify the scenario part of the message
