Trailer hitch connection?

[Bob_Sheaves]

...
Oh, Bob, were you thinking along the lines of an air hose QD, with it's captured balls & sliding sleave?

Same idea...different application. I was thinking hydraulic QD's, because of the larger angle on the lock ramps and the allowance for rotary action in the joint without leaking (altho leakage for this application is not a concern, since you are not sealing in any liquid). Minor point of difference between air and the mil-spec hyd. QD's....no big deal.

Best regards,

Bob Sheaves
CEO
catNET Incorporated
http://www.catnetsolutions.com

 

[ntsqd]

I'll see if I can amend the model tomorrow.

 

[Tucson T4R]

I'm still sold on the Tregg hitch. Proven design and has been used for years offroad. The spring loaded pin to couple the Tregg block into the hitch is a simple and easy hook up. I also like that the pivot cylinder on the trailer has grease fittings. Super quiet offroad. Me like it. :jumping:

 

[RunninRubicon]

Ball and socket

I guess I'll just thow in a wrench here and say that I don't have an issue with the original ball hitch. I do pull a light-weight trailer-maybe 700lbs loaded but on only one occasion did I get things out of contol so bad that the trailer tried to roll-over. Because of the inherent limiting characteristics of the hitch it prevented this and kept the rubber side down. No harm no foul. PERHAPS in a heavier trailer the risk of damaging the hitch or flipping both rigs over could I see this an possibility. I see mine working well the way it is thanks.

 

[Willman]

An an addendum, the "homebrewer" can make a better design out of some commonly available truck parts-a set of yokes from an 1810 truck ujoint equipped propshaft and scaling up the design of a ball locking hydraulic quick disconnect coupling.

Using the ujoint 1st yoke, machine a square hole in the tube end for a 2" hitch bar and weld securely (I am purposely leaving out the heat treating, annealing, specs etc so everyone has something to look up before attempting this...LOL). Install the 1810 joint to the yoke. This becomes the truck end of the hitch.

Using the second joint yoke, machine a round hole of 2.5" dia in the tube side to insert a machined spud shaft with a retaining ring and groove for the ball retention. Now you would machine a coupler with a sliding sleeve with the ball ramps included and assemble with 12 1/4" dia hardened steel balls. This coupler allows rotation through the ball coupling, fore aft rotation thru the joint, and left right rotation thru the joint also.

Just an idea guys.....

Best as always,

Bob Sheaves
CEO
catNET Incorporated
http://www.catnetsolutions.com/

I would love to see a picture of your idea vs. ntsqd idea!

:jumping:

 

[Willman]

I guess I'll just thow in a wrench here and say that I don't have an issue with the original ball hitch. I do pull a light-weight trailer-maybe 700lbs loaded but on only one occasion did I get things out of contol so bad that the trailer tried to roll-over. Because of the inherent limiting characteristics of the hitch it prevented this and kept the rubber side down. No harm no foul. PERHAPS in a heavier trailer the risk of damaging the hitch or flipping both rigs over could I see this an possibility. I see mine working well the way it is thanks.

Great point!! I have even thought of putting a limit on my new and up coming off-road hitch to prevent roll over.....Still thinking on how I'm going to do it as well.

 

[ntsqd]

I'll try to update my model to what I believe Bob's idea to be is tomorrow. Work may get in the way though.......

My long shelved design had provision for roll-over control. My thinking was that if you could prevent a "light" trailer flop that is was worth doing, but if the trailer threatened to take the tow rig with it then let the trailer go. My great Uncle had this happen, trailer (early Airstream) rolled and took the tow car with it. He had a little difficulty telling his brother-in-law (my grandfather) what happened.

 

[ntsqd]

OK, IF I understood Bob's QD concept this is what is would roughly look like:

To disconnect or remove the coupler the red sleeve would be slid fwd against the spring, which allow the white balls to retract out of the groove in the center shaft.

My thot while modeling this is that the averagely gifted, well tooled home designer/fabricator would have some trouble making this work well & last. Just in modeling it w/o engineering concerns I discovered some nuances to the geometry.

I'm sure that it can work, I'd just advise anyone not well versed in this sort of design & fab whom is considering trying it that they consult with someone or multiple someones over the duration of the project.

 

[bc_fjc]

speeking from experiance I would much rather have the trailer roll and save the truck then risk rolling the trailer and truck or damaging the truck. Both trailer and tent only took minor damage.

 

[Bob_Sheaves]

OK, IF I understood Bob's QD concept this is what is would roughly look like:

To disconnect or remove the coupler the red sleeve would be slid fwd against the spring, which allow the white balls to retract out of the groove in the center shaft.

My thot while modeling this is that the averagely gifted, well tooled home designer/fabricator would have some trouble making this work well & last. Just in modeling it w/o engineering concerns I discovered some nuances to the geometry.

I'm sure that it can work, I'd just advise anyone not well versed in this sort of design & fab whom is considering trying it that they consult with someone or multiple someones over the duration of the project.

DAMN! Ya done good!

That illustrates the concept exactly...altho' it does not address several manufacturing and safety issues (which you have correctly noted), the illustration shows how simple the idea is. Perhaps I am over estimating the capabilities of the "average" homebrewer...but the details are easy enough to work out by following "Machinery's Handbook" & "Mark's" practices.

...or we can cover them here (I don't want to make this a "Bob's Design School" thread and take over) if there is enough interest and the moderators approve.

Best as always,

Bob Sheaves
CEO
catNET Incorporated
http://www.catnetsolutions.com

 

[Mike S]

On my trailer I designed a simple 360 degree lunette on a .75" shaft that fits through a 3/4" hole in an end plate bolted to a plate welded to a 5' section of 2" square tubing with 1/4" wall. The shaft carries a flat bushing and spring with a double nut to hold it in place inside the tube. The tube fits into the trailer frame which has a receiver at the front of the frame. The lunette fts a standard pintle hook hitch on the Kaymar bumper.

The 'low tech' result is a strong, 360 degree hitch that is adjustable from 18" to 48" in length. Useful on road and off.

Mike S

 

[Bob_Sheaves]

There is one major issue with any lunette/pintle design and that is one of control over the trailer. A pintle, by design is a sloppy fit to the lunette eyelet. This allows unwanted and undesirable "wobble" in the trailer at high speeds (one of the reasons the military limits their trailers to 55mph max.) due to potential alignment issues with a single, but especially a multiple, axle trailer. The CG of the trailer can be misloaded through carelessness or lack of knowledge and can have a harmonic effect leading to a rollover.

Generally speaking, in the commercial trailer building industry, lunettes are not used under 20K lb GVWR for just this reason. Precise and predictable control over the trailer is a liability issue for manufacturers. Look at the people towing trailers well over 70mph on the freeways anywhere in the US interstate road system...... An accident looking for a place to happen.

I am not saying you are wrong, not at all.. all I am asking is, be careful in what you do.

Best regards,

Bob Sheaves
CEO
catNET Incorporated
http://www.catnetsolutions.com

 

[Mike S]

Bob

I have a single axle trailer that loads to about 1200 to 1500 lbs. Tongue weight slightly over 10% of the loaded trailer weight. I have hauled it many thousands of miles over the Western states behind my FJ60 and my FZJ80. It tows flat and tracks straight with no wobble or bouncing, even at 70 mph. Guess I'm lucky it hasn't turned over yet.

Mike S

 

[Willman]

On my trailer I designed a simple 360 degree lunette on a .75" shaft that fits through a 3/4" hole in an end plate bolted to a plate welded to a 5' section of 2" square tubing with 1/4" wall. The shaft carries a flat bushing and spring with a double nut to hold it in place inside the tube. The tube fits into the trailer frame which has a receiver at the front of the frame. The lunette fts a standard pintle hook hitch on the Kaymar bumper.

The 'low tech' result is a strong, 360 degree hitch that is adjustable from 18" to 48" in length. Useful on road and off.

Mike S

Love to see a picture of your hitch setup!!! Sounds like another option....

:chowtime:

 

[Mike S]

Love to see a picture of your hitch setup!!! Sounds like another option....

:chowtime:

Will, I'll try to post a photo tomorrow.

Mike S