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Why are you convinced that the cable will break? It's not having to lift the trailer and payload, just apply the brakes.
Trailer breakaway cable
- Thread starter ridgy
- Start date
Why are you convinced that the cable will break? It's not having to lift the trailer and payload, just apply the brakes.
Refueler
Well-Known Member
If as shown there is no secondary connection of trailer to vehicle - the length of breakaway cable would be too short to cause trailer brake to operate and allow time for vehicle to stop once driver realises somethings wrong.
The breakaway cable is not capable of having such weight till trailer and vehicle stopped. Think of the snatch load ... it will be huge ! even on a small trailer.
OH and let me correct someone elses misrepresentation of my posts ... because I say a Breakaway cable is different to a secondary connection - the chain - does NOT automatically say both should be fitted. If anyone cares to go back - they will find my post saying that my trailers did not have both fitted ....
[159032]
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I find now that the breakaway cable is expected to break.
That sounds a bit bonkers to me.
One of the slightly less interesting videos I have seen.
.
That sounds a bit bonkers to me.
One of the slightly less interesting videos I have seen.
.
halcyon
Well-Known Member
Your coupling was out of date in the early 1970's, it goes back to the days of few trailers going at a low speed. Spring control was very basic but all we had, with the advent o gas filled dampers the world of trailer rakes changed. The only thing we used them on was mobile air compresses, even these were being replaced with damper type over-run hitches by mid 1970.
Fit a new coupling with modern damping on over-run.
Brian
Refueler
Well-Known Member
Gor Blimey Guv !!
It still does not answer the important question ... how does the trailer brake stay on after cable breaks ?
halcyon
Well-Known Member
Yes the breakaway cable is supposed to break, all part of type approval of overrun braking systems.
The Yanks were keen on safety chains and little braking in the old days for boat trailers, but did not meet UK regs. We had chains on air braked commercial trailers from memory.
Brian
Refueler
Well-Known Member
Cmon ... then show us the more modern and show how it works to hold brake on after cable breaks.
I've searched and all I can find that would lock on is an electric system used in Australia and USA - which requires modification to comply with UK rules ...
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halcyon
Well-Known Member
When Harry and Ken started making your coupling you did need to fit a breakaway cable. Breakaway cables were fitted to some spring over-run hitches for A-frame couplings for caravans, these had a lever operated by over-run and a separate handbrake lever, that operated the overrun brake lever also.
Brian
VicS
Well-Known Member
[
Its a powerful spring that holds the hand brake lever on once the cable has pulled it past the "overcentre" position
Reasonably well explained here
Hi Roger
Its a powerful spring that holds the hand brake lever on once the cable has pulled it past the "overcentre" position
Reasonably well explained here
Refueler
Well-Known Member
Now we are getting somewhere ....
Hot Property
Well-Known Member
My Bailey caravan has a gas strut that pushes the brake on. In order to release it considerable pressure needs to be applied. When the breakaway cable operates, the handle springs up under the gas strut pressure. I have no doubt that should the coupling fail, then the brakes would be applied and stay firmly on!
Refueler
Well-Known Member
Good ... as with the Energy store ... we are now getting info to show that it can be done.
As I posted - my caravaning ended in the 90's and we did not have any system to lock the brakes on, other than the ratchet pawl ... all they did was to brake as long as cable was tensioned .. and as far as I remember - my last van with the auto reversing brakes was about the best then !!
Just a comment ... those auto brakes to allow you to reverse the van were very temperamental ! You had to ease the car so slow back to get the van to NOT lock its brakes ... I always reckoned the locking U plate on the hitch shaft was much better ! Number times I'd start backing up and trailer would lock ...
JumbleDuck
Well-Known Member
My Drascombe trailer has a system like that. It works quite well ... but it has auto-reverse brakes which (duh) don't work in reverse, whether the impetus comes from the car or gravity. In other words, you can't use the brake handle to control it down a launching ramp and the gas strut won't stop it from rolling downhill if it breaks away on a slope.
JumbleDuck
Well-Known Member
I never understood how auto-reverse brakes worked until I got one and opened up a hub to find out. Basically itrelies on the braking mechanism rotating backwards and folding up slightly when the drum turns backwards. To work reliably several parts need to be able to slide or swivel freely. As you say, a U-plate is much more reliable.
KREW2
Well-Known Member
If you have auto reverse brake drums it is essential that you fit an energy store. Without it your handbrake will not work if the trailer is parked on a slope, with the rear of the trailer facing down the incline.
Capt Popeye
Well-Known Member
Well suggest that the cable is called a 'breakaway cable' for that reason, its designed to allow the trailer / car to 'break away' from each other when they part company ?
rogerthebodger
Well-Known Member
I agree
Vic that shows the handbrake is NOT operated by th overrun coupling but is separate. Its was I would call an over center lock which works similar to a ratched handbrake.
The main change is that the overrun coupling does not operate the brake via the handbrake lever so there must be a seperate lever to pull the brake on when the car brakes and the trailer runs forward either on a spring or damper.
It is clear from Vic's Video that the breakaway cable is connected to the separate handbrake which can have what is called an energy store but is to me just an overcenter lock.
So I understand now.
I still prefer the chain over the tow hitch as this ensures the trailer will still be attached to the car if the coupling comes adrift. There could be some improvement to ensure the chain cannot jump off the hitch as well but twisting the chain aids that anyway.
KREW2
Well-Known Member
Yes the cable brakes, but bit should have activated the braking system first.
duncan99210
Well-Known Member
OK, I hadn’t realised what folks weren’t understanding about breakaway and how hand brakes are now separated from the overrun brakes. The Alko catalogue here https://www.alko-tech.com/sites/def...9418-katalog-auflaufeinrichtungen-2017-en.pdf has a number of drawing of their hitches and brake mechanisms, along with a brief explanation of the minimum requirements for braking systems.
Most of the hand brakes are, as someone has said above, over centre levers which can be activated either by hand or the breakaway cable. The ones I’m familiar with use a gas strut to hold the lever in the “brakes on“ position which requires considerable effort to move from on to off and vice versa (that’s the energy store talked about above). Some others types use a push button ratchet, but that’s prone to failure in trailers that spend much of their lives sat around doing nothing. Yet others I’ve encountered use both a gas strut and a ratchet.
Hope that helps to clear things up: if anyone is really interested, I can photo hitches and post on here next time I have reason to visit the gig trailers.
Most of the hand brakes are, as someone has said above, over centre levers which can be activated either by hand or the breakaway cable. The ones I’m familiar with use a gas strut to hold the lever in the “brakes on“ position which requires considerable effort to move from on to off and vice versa (that’s the energy store talked about above). Some others types use a push button ratchet, but that’s prone to failure in trailers that spend much of their lives sat around doing nothing. Yet others I’ve encountered use both a gas strut and a ratchet.
Hope that helps to clear things up: if anyone is really interested, I can photo hitches and post on here next time I have reason to visit the gig trailers.
Refueler
Well-Known Member
Total poppycock ! Please explain how all those 1980 's caravans with auto reverse brakes were successfully handbraked like mine ?
The handbrake when put on with trailer stopped .. means the brake shoes move out to braked without the auto reverse mechanisn having flipped over. The auto reverse can only activate when brake is NOT on and is why you have to start moving back so slow - to avoid putting the brake on ... then it flips and you can then reverse - STILL slowly.