Lock for caravan drawbar

The frame should also work to lock the coupling together whereas the ball won't.

I have used a hitch helmet for some years when towing a boat and when boat parked at home. However I do not have anymore use as it will not fit offroad hitch on camper trailer. It is still in good condition in Brisbane. Of course you will need to prevent coupling from being unbolted from drawbar. I also used a locking pin through towbar instead of standard pin as I didnt want to return to ramp and find trailer missing

https://www.whitworths.com.au/main_itemdetail.asp?cat=138&item=91169&intAbsolutePage=1

Brian mine is from Autobarn @ $ 60 for the lockable pin to pass thru the towbar to lock the goose neck and the other bit comes up form under the big nut and covers it and it has 2 hardened shafts that come up either side of the coupling and you fit a hardened female bracket over the holes the shaft has indentations so when you push it hard onto the top of the towball coupling and lock it ,thats it.I have had them for 10 years for my works trailer.I lost the key once and it took me 5 mins with a 6 foot crowbar and mash hammer to get it off and it was wrecked .Cheers John

Gooday,
You should be aware that a lock on the coupling is only going to slow down the Buggers, what they do is shackle the safety chain, or chains, short, drop them over the tow ball of the thieves vehicle form until they get clear of where they stole it and then get out a cordless grinder, if the hammer does not work, and hitch it up properly and off they go.
I have a Klampit Wheel clamp but they like most other precautions only slow down the experts. If you are able to concrete an anchor in the ground where you store it and put some decent chain around the axle they will most likely be too lazy to get under there and look for something easier.
Cheers,
Boroma604.

Either will suffice for insurance purposes, if parked in an unlocked yard or street.