Reply
 
Thread Tools Search this Thread Display Modes
 
Old 12-26-2007, 03:50 PM   #57
Rivet Master
 
JimGolden's Avatar
 
Vintage Kin Owner
1977 31' Excella 500
Berkeley Springs , West Virginia
Join Date: Sep 2005
Posts: 1,619
Images: 7
New Hitch

Hey Gang,

Check this out. Looks like a new and improved Hensley design in town, and at 2/3 the price.

The Jim Hensley Hitch Story | ProPride, Incorporated
__________________

__________________
- Jim
JimGolden is offline   Reply With Quote
Old 12-26-2007, 04:10 PM   #58
Rivet Master<br><img src="/ugala/forums/images/5rivet.gif">
 
CanoeStream's Avatar

 
2006 25' Safari FB SE
St. Cloud , Minnesota
Join Date: Aug 2003
Posts: 13,279
Images: 19
Blog Entries: 3
Quote:
Originally Posted by JimGolden
Looks like a new and improved Hensley design in town, and at 2/3 the price.
That has received some discussion here for several weeks now. The thread was last posted to about 3 hours ago.
__________________

__________________
Bob

5 meter Langford Nahanni

CanoeStream is offline   Reply With Quote
Old 12-26-2007, 04:37 PM   #59
4 Rivet Member
 
Livingston , Texas
Join Date: Dec 2007
Posts: 394
Hensley Linkage at 4 Degree Angle

As the angle between TV and TT increases to 1 degree, 2 degrees, 3 degrees, and 4 degrees, the VPP moves to locations indicated by the 2nd, 3rd, 4th, and 5th x's respectively, as shown below.

When the angle reaches slightly more than 4 degrees, the VPP is at its maximum lateral excursion. It also in important to note that, at this relatively small articulation, the VPP has moved rearward about 24" from the 0 degree position. This means the reduction in steering torque is considerably less than when the linkage is in the centered orientation.

At each angle, the trailer swings as though its tongue were extended to the location of the VPP and the TT is pivoting about the VPP. At 4 degrees, the linkage has rotated so that the ball coupler now is offset about 3" from its centered position. And, the ball has moved forward about 1" relative to its centered position.


__________________
Ron Gratz is offline   Reply With Quote
Old 12-26-2007, 05:26 PM   #60
4 Rivet Member
 
Livingston , Texas
Join Date: Dec 2007
Posts: 394
Hensley Linkage at 10 Degrees

When the articulation reaches 10 degrees, the VPP has moved almost all the way back to the hitch. The VPP is about 9" forward and 9" to the side of the centered position of the ball. In 10 degrees of rotation of the linkage, the forward projection of the ball has decreased from about 52" to about 9". The TT continues to swing as though it were pivoting about the VPP.

When the articulation reaches about 15.5 degrees, the right link will be co-linear with the front link; and the VPP location will coincide with the center of the left front pin. The ball will have reached its maximum excursion of about 5". The forward projection of the VPP will be about 5".

Beyond the 15.5 degree angle, the linkage begins to "collapse" quite rapidly and the ball moves back toward the centerline. The maximum forward excursion of the ball is about 6.4" at an angle of about 62 degrees.
__________________
Ron Gratz is offline   Reply With Quote
Old 12-26-2007, 07:57 PM   #61
_
 
. , .
Join Date: Dec 2004
Posts: 8,812
hi ron and welcome to the asf...

i've seen your posts on other forums and the nice diagrams.

it's not obvious, but we have covered how the haha works in many other threads.

just not this one.

till now.

cheers
2air'
__________________
all of the true things that i am about to tell you are shameless lies. l.b.j.

we are here on earth to fart around. don't let anybody tell you any different. k.v.
2airishuman is offline   Reply With Quote
Old 12-26-2007, 11:11 PM   #62
Rivet Master
 
ROBERTSUNRUS's Avatar

 
2005 25' Safari
Salem , Oregon
Join Date: Mar 2006
Posts: 7,269
Images: 18
Blog Entries: 51
Hi, nice diagrams, but it's all "Hong-Kong" to me. In other words, it might as well be printed in Chineese. Maybe a picture or diagram, in scale, showing the relationship between the tow vehicle and trailer would work better. And a side by side compairison [non Hensley hitch] showing the different positions of tow vehicle, tow ball, pivot points [vertual and real] and trailer. Also, at the 10 degree angle, looks like "Jack-Knife" to me. And will the tow ball actually move between 5" and 6.4"?
__________________
Bob

2005 Safari 25-B
"Le Petit Chateau Argent"
[ Small Silver Castle ]
2000 Navigator / 2014 F-150 Eco-Boost / Equal-i-zer / P-3
YAMAHA 2400 / AIR #12144
ROBERTSUNRUS is offline   Reply With Quote
Old 12-27-2007, 08:26 AM   #63
4 Rivet Member
 
Livingston , Texas
Join Date: Dec 2007
Posts: 394
Quote:
Originally Posted by ROBERTSUNRUS
Hi, nice diagrams, but it's all "Hong-Kong" to me. In other words, it might as well be printed in Chineese. Maybe a picture or diagram, in scale, showing the relationship between the tow vehicle and trailer would work better. And a side by side compairison [non Hensley hitch] showing the different positions of tow vehicle, tow ball, pivot points [vertual and real] and trailer. Also, at the 10 degree angle, looks like "Jack-Knife" to me. And will the tow ball actually move between 5" and 6.4"?
Good suggestions. Actually, you're one step ahead of me. The comparison diagrams will be next.

Your "Jack-Knife" comment made me realize the diagrams need further explanation. The longitudinal centerline of the tow vehicle is on the plot's vertical axis. This means that in all diagrams, the tow vehicle is pointed up with its centerline in the left-right center of the plot. An angle of 10 degrees should not present a jackknife situation. Perhaps the next set of diagrams will better explain this.

Yes, the HA's tow ball can move laterally plus or minus 5" and can move forward 6.4" relative to its "centered" position. The HA is based on a 4-bar linkage. The rear unit which holds the tow ball is one of the links. In order to have a yaw angle between the trailer and the tow vehicle, the rear unit must simultaneously rotate and move laterally. The diagrams show the relative movement among the links.

Ron
__________________
Ron Gratz is offline   Reply With Quote
Old 12-27-2007, 08:49 AM   #64
2 Rivet Member
Commercial Member
 
Hensley Ron's Avatar
 
Currently Looking...
Oxford , Michigan
Join Date: Dec 2007
Posts: 95
This is why us engineers aren't allowed to talk on the phone with customers. I love Ron's diagrams. The 4 bar linkage is not as difficult as it appears. Build one out of toothpicks, Legos, whatever you like. With nothing "pinned down," it can rotate anywhere you like. Those are "degrees of freedom." By fixing one or more points, you limit the degrees of freedom. The trapezoidal (as opposed to a simple rectangle) design allows the tow vehicle to maintain a mechanical advantage over the trailer.

Listen, it's just a tool, like any other. A set of pliers puts a tight grip on an object in one direction, falls off in the other. The linkage system at the heart of the Arrow has been in existence for a long time, someone just decided to try it in a hitch application.

By the way, the Lego video was done by a Hensley customer without any prompting from us. We stumbled across it and put it on the web site. Maybe I'll put Ron's drawings on there. Physics always was my favorite subject (really).
__________________
Ron Estrada
Hensley Mfg., Inc.
www.NoSway.com
Hensley Ron is offline   Reply With Quote
Old 12-27-2007, 11:03 AM   #65
Ready-to-Travel
 
pmclemore's Avatar

 
2012 30' International
Walkerton , Virginia
Join Date: Dec 2003
Posts: 2,494
Ron,

Your last sentence explains a lot. The video is worth much less than you paid for it and detracts from your product.

Other than that...

Pat
__________________
pmclemore is offline   Reply With Quote
Old 12-27-2007, 02:37 PM   #66
2 Rivet Member
Commercial Member
 
Hensley Ron's Avatar
 
Currently Looking...
Oxford , Michigan
Join Date: Dec 2007
Posts: 95
But it gives grown men a great excuse to play with Legos!
__________________
Ron Estrada
Hensley Mfg., Inc.
www.NoSway.com
Hensley Ron is offline   Reply With Quote
Old 12-27-2007, 02:54 PM   #67
Rivet Master
 
byamcaravanner's Avatar
 
1967 28' Ambassador
1963 19' Globetrotter
1970 29' Ambassador
Waukesha , Wisconsin
Join Date: May 2007
Posts: 1,180
Quote:
Originally Posted by pmclemore
The video is worth much less than you paid for it and detracts from your product.
I agree... it likens the product to "snake-oil" maybe you could re-do the video in an accurate depiction of the hitches function.
__________________
Steve & the crew
'70 Ambassador International Twin
'63 19' Globetrotter TAC WI-1
http://byamcaravanner.blogspot.com/
byamcaravanner is offline   Reply With Quote
Old 12-28-2007, 08:29 AM   #68
2 Rivet Member
Commercial Member
 
Hensley Ron's Avatar
 
Currently Looking...
Oxford , Michigan
Join Date: Dec 2007
Posts: 95
Joking aside, I agree. We've made several attempts to show how it works. It seems it's never enough info or too much. The price of computer animation has come down quite a bit in the last few years, though, so I may have to re-visit that. We have the same problem with our TrailerSaver 5th wheel hitch.
__________________
Ron Estrada
Hensley Mfg., Inc.
www.NoSway.com
Hensley Ron is offline   Reply With Quote
Old 12-30-2007, 09:18 AM   #69
4 Rivet Member
 
Livingston , Texas
Join Date: Dec 2007
Posts: 394
Comparison Diagram -- Hensley, PullRite, Conventional

Quote:
Originally Posted by ROBERTSUNRUS
---Maybe a picture or diagram, in scale, showing the relationship between the tow vehicle and trailer would work better. And a side by side compairison [non Hensley hitch] showing the different positions of tow vehicle, tow ball, pivot points [vertual and real] and trailer.
Following is a diagram showing basic features of the Hensley Arrow, PullRite, and "conventional" hitches. The tow vehicle is modeled after a Suburban with wheelbase = 130". The distance from the rear axle to the ball of a conventional hitch is assumed to be 65".

The HA's ball, when centered, is assumed to be 77" behind the rear axle. This means the HA's VPP, when the linkage is centered, will be 77-52 =24" behind the TV's rear axle. At a yaw angle of 4 degrees, as shown in the diagram, the HA's VPP has moved rearward about 24" and laterally about 19".

For comparison, the PullRite's pivot point remains fixed at 12" behind the rear axle. I have assumed the PR adds 60" of length to the TT's tongue.

The enlarged diagram shows the different pivot points and the relative positions of the TT's tongue when using the different hitch systems. The unique feature of the HA is its variable virtual pivot point location shown by the yellow path.

The way in which each hitch transfers lateral force from the TT to the TV is a primary factor in yaw stability. The distance from the TV's rear axle to the point of application of lateral force is a "lever arm" over which the lateral force acts to generate a "steering torque" on the TV.

For the conventional hitch without sway control, the lever arm in this example is 65". For the PullRite, the lever arm is 12". For the HA, the lever arm varies from about 24" when the linkage is centered, to about 48" at a 4-degree yaw angle, to about 70" at a 15-degree yaw angle. However, if the TV had a shorter rear overhang, then both the HA and the conventional would have a shorter lever arm.

Discussions about how the HA works usually involve comments about the linkage being "locked" so as to prevent the TT from swinging behind the TV. There is no locking mechanism. The TT and TV are connected via four roller bearings. The HA's rear unit is free to translate and rotate relative to the front unit.

If you could lift the tires of a PullRite-equipped TT off the ground, you could swing the TT with no resistance from the hitch. If you lifted the tires of a TT coupled via a convential hitch with no sway control, you could swing the TT with no resistance. And, if you lifted the tires of a HA-equipped TT, you could swing the TT with no resistance from the HA's linkage.

It is also a myth that a HA-equipped TT cannot "steer" the TV. As long as the "lever arm" is not zero, a TT can steer the TV if the TT exerts lateral force. With a PullRite, it appears there is no steering because the steering torque is significantly reduced. With a HA, it appears there is no steering because the HA also reduces the steering torque. Contrary to what you might read in advertising literature, the HA does NOT 'make the vehicle combination "think" and "act" like a straight unit, a straight truck if you will.'

Ron




__________________
Ron Gratz is offline   Reply With Quote
Old 12-30-2007, 10:55 AM   #70
1 Rivet Member
 
Currently Looking...
Rochester Hills , Michigan
Join Date: Dec 2007
Posts: 15
Quote:
Originally Posted by Ron Gratz
.............................
Discussions about how the HA works usually involve comments about the linkage being "locked" so as to prevent the TT from swinging behind the TV. There is no locking mechanism. The TT and TV are connected via four roller bearings. The HA's rear unit is free to translate and rotate relative to the front unit.

If you could lift the tires of a PullRite-equipped TT off the ground, you could swing the TT with no resistance from the hitch. If you lifted the tires of a TT coupled via a convential hitch with no sway control, you could swing the TT with no resistance. And, if you lifted the tires of a HA-equipped TT, you could swing the TT with no resistance from the HA's linkage.

It is also a myth that a HA-equipped TT cannot "steer" the TV. As long as the "lever arm" is not zero, a TT can steer the TV if the TT exerts lateral force. With a PullRite, it appears there is no steering because the steering torque is significantly reduced. With a HA, it appears there is no steering because the HA also reduces the steering torque. Contrary to what you might read in advertising literature, the HA does NOT 'make the vehicle combination "think" and "act" like a straight unit, a straight truck if you will.'

Ron

I am just relying on a full scale model I build and it doesn't support what you are telling here..


I hold the TV side of the model in my RH and try to twist or move the TT side of the model (simulating yaw, sway...) then the entire model moves.. This trapezoid is LOCKED once you induce a movement from the TT and the trapezoid is flexible once you induce a move from the TV.
Attached Thumbnails
Click image for larger version

Name:	IMG_2435 (Small).JPG
Views:	55
Size:	106.5 KB
ID:	51699  
__________________

__________________
ZenfookPower
ZenfookPower is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Solar<><>this Works For Us ROBERT CROSS Generators & Solar Power 10 09-09-2007 09:10 PM
Beach '65 Carvel Rewiring Simplified PoconoAir Electrical - Systems, Generators, Batteries & Solar 2 06-06-2007 09:14 PM
It works garry Off Topic Forum 3 06-30-2006 01:15 AM
A/C kinda works skidmark Furnaces, Heaters, Fireplaces & Air Conditioning 0 08-27-2005 11:45 PM
my DC works only sometimes Tomcat Electrical - Systems, Generators, Batteries & Solar 2 04-27-2003 12:26 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 03:55 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.