Pintle Hitch Question

[BarnyardEngineering]

(quoted from post at 12:46:45 03/22/23) Would you really want a pintle hook where the full weight of the trailer is constantly pulling on the locking mechanism.

Every tractor trailer on the road is constantly pulling on the locking mechanism of the 5th wheel, yet it is considered so secure that safety chains are not necessary.

 

[BarnyardEngineering]

(quoted from post at 19:50:52 03/22/23) Just my opinion for what it is worth. Looks to me to be very UNhandy. Would have to get out to adjust height of hitch, oops that was 1/2 inch too high, let it down a bit, try again, back in to couple, get out again to lift landing leg, then go. Repeat when unhitching. Of course could have a helper to do all that while the driver stays in the seat.

Where these are used the wagon tongues are held up by springs or friction, no landing legs. They're set at the correct height for the machine moving them around.

Not to mention with the pintle hitch open there's a several-inch range where the hitch will "funnel" the eye into the hitch. If you're a "half inch off" it will slide right in.

 

[john in la]

Fritz now you are trying to compare apples to oranges.

The latch of a 5th wheel moves side to side.
A bar comes out a hole on one side and into a hole on the other side.
Where as the king pin is pulling backwards against the bar.
So the king pin is not pulling in the direction of the bar moving open.

A normal pintle hook is U shaped with a locking latch on top.
So the trailer is pulling back against the body of the pintle hook.
Not the latch over the opening.

The pintle hook in this post is set up to where the trailer is pulling in the direction the hook opens.
So the latch is the only thing holding it closed and the trailer attached.

 

[BarnyardEngineering]

On any of the 5th wheels I have seen the kingpin is secured by jaws that grab around the kingpin.

This is a 5th wheel from a pickup but the concept is similar on the big rigs:

 

[Traditional Farmer]

I've seen those hitches on airport tugs where the tractor was used to pull the baggage carts around.Easy to hook and unhook from the tractor seat

 

[john in la]

The orange part number 2 spins and locks around the king pin
preventing the jig pin from moving up due to the lip on the
bottom of the king pin. The blue part number 4 then slides
over behind the orange part preventing it from spinning to the
open position. So all the force is applied to the blue part in a
direction that is not trying to push it open.

When you pull the release handle you are moving the blue
part number 4 out the way. This allows the orange part
number 2 to spin as you pull away.