How do the auto-reverse trailer hitches work?
If a trailer starts pushing a vehicle it applies the brakes - ie over run braking. How is this different from the vehicle pushing the trailer in reverse ? With my current over run (but NOT auto reverse) trailer hitch I have to hop out and imobilise the brakes, and the auto version is supposed not to need this - but how the heck does it work???
AWEM
Wheel direction ?
Steve
In an 'ordinary' brake the lining is attached to the shoe and when the brake is applied the lining is forced against the drum.
In an auto reverse brake the shoe and lining(supported on a metal carrier) are effectively two separate items. In forward motion when the brake is applied the two parts act as though connected as in an 'ordinary' brake. In reverse motion, however, the motion of the drum forces the lining/carrier to dislocate themselves (for want of a better word) from the shoe and the lining is not forced against the drum.
This is the best picture that I could find - there must be better ones somewhere:
A prettyly-coloured picture here:
In normal forward rotation the drum motion and the force from the two little green springs holds the 'hook' in the carrier/lining against a pin in the shoe making the two act as one.
With reverse drum rotation, the drum drags the carrier/lining with it and 'dislocates' it from the shoe stretching the little green springs as it does so.
Purely out of interest Andrew, did you see my reply re. Quadratech?
Richard
reverse)
Richard, yes thanks - It's printed out on my desk and awaiting a phone call on Monday !
AWEM
Excellent!
As like as not you'll speak to Pat in the office.
Richard
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