Slimy38
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| posted on 10/10/20 at 10:45 AM |
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What defines a 'handbrake'?
Before anyone answers with 'check the IVA manual' that's where I'm going shortly....
For a bit of context, I want to do an under dash handbrake for my car. I saw it on the HSR demo car at Stoneleigh and I like the idea. Problem is I
don't like how it looks like a regular handbrake that has just been put in the wrong place. A very recent question on here pointed me to a batch
of Caterhams that did the same but under the passenger dash, and again they seem to use the normal handbrake.
I'd like to use something like an old Mercedes pull-type handbrake, but from memory the release mechanism was a floor mounted push button. I
then had other thoughts around old manual choke mechanisms, but then I figured the forces required would overcome the 'friction twist'
locking mechanism that they used. I did find this on the internet, not sure how I'd create something like that or plumb it in;
https://www.roughtrax4x4.com/genuine-toyota-handbrake-pull-leve
r-46110-35230.html
So as I try and look for handbrake inspiration, what are the key points it has to cover? My limited understanding suggests that it has to operate the
rear brakes to a point where the car no longer moves, and that it is lockable in that position. I'm guessing some sort of mechanical assistance
is required, some sort of gear or lever arrangement?
I don't want to go as far as using an electric handbrake.
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belgian2b
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| posted on 10/10/20 at 10:59 AM |
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Just give a look at the 2CV handbrake lever
Gerardo
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SteveWalker
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| posted on 10/10/20 at 11:30 AM |
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Long ago, my father's car had an under-dash handbrake (probably on his Vauxhall Victor 101 Super, as that had a column shift and a bench seat,
so no space for a conventional handbrake). A handle that was pulled straight out and held by a ratchet. Release was by rotating the handle. I'm
sure such a handle could be found amongst classic car parts - or even constructed (it is only a round shaft, sliding in and out, with teeth and a
ratchet on one side and that can be rotated to move the teeth away from the ratchet.
Mechanical advantage depends upon the length of the arms operating the rear brakes and the movement of the cable - increase the travel and the length
of the arms for more force at the brakes. Or an intermediate arm could be used, with the front cable connected to a point further out from the pivot
than the rear cable to the brakes.
[Edited on 10/10/20 by SteveWalker]
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steve m
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| posted on 10/10/20 at 11:52 AM |
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My old Lotus Elan 2+2 had the below the dash pull out handbrake lever, and it never filled me with any confidence. and scraped through the Mot every
time,
Steve
Thats was probably spelt wrong, or had some grammer, that the "grammer police have to have a moan at
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scudderfish
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| posted on 10/10/20 at 01:28 PM |
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The Dax Rush had a handbrake under the steering column.
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snapper
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| posted on 10/10/20 at 01:39 PM |
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Some under dash pull handbrakes had a release button
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
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obfripper
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| posted on 10/10/20 at 03:21 PM |
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A mk1 Isuzu Trooper had an umbrella pull handbrake, early Hilux's & Hiaces, Mazda B2000 and pickups also had them into the '90s.
They generally use a cable from the pull rod to a secondary lever which multiplies your effort and transfers the force to the main handbrake cables,
the ratchet mechanism is integral to the pull rod and is either a twist release, or a button on the handle.
The setup does depend on having somewhere suitable to mount the secondary lever, and enough room for the telescopic action of the pull to operate,
iirc there is 10-12" of travel on most of these setups, to move the main cables 1-2".
The above vehicles have a straight line pull to the secondary lever so no effort is lost in friction in a bowden cable, that isn't realy
possible in the confines of a 7 type body so a bowden cable will be needed, this may require a change in secondary lever ratio to get the required
effort.
Dave
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