Technical name for a pushable hinge

General cycling advice ( NOT technical ! )
stoobs
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Re: Technical name for a pushable hinge

Post by stoobs »

In fact, thinking about it, don't most car doors have 2 such positions when open?

A "detent hinge"
mrjemm
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Re: Technical name for a pushable hinge

Post by mrjemm »

I don't think all QR are what you would call "over centre" going by the descriptions above- not all have a reduction in tension as you reach closure- some just get stiffer continuously. These would be more of a reduction of increase of cam radius, rather than an actual reduction in cam radius, that would be how I imagine an over-centre... And often the springiness in the QR is actually in the structure (i.e. seat clamps) rather than the skewer.
LANDSURFER74

Re: Technical name for a pushable hinge

Post by LANDSURFER74 »

if you do not feel a reduction in tension as the lever goes over centre then the tension is set too high and the possibility of it springing open in use is very real ,,, be worried !
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horizon
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Re: Technical name for a pushable hinge

Post by horizon »

LANDSURFER74 wrote:if you do not feel a reduction in tension as the lever goes over centre then the tension is set too high and the possibility of it springing open in use is very real ,,, be worried !


Yes, as it possibly hasn't passed the point of no return.
When the pestilence strikes from the East, go far and breathe the cold air deeply. Ignore the sage, stay not indoors. Ho Ri Zon 12th Century Chinese philosopher
Gearoidmuar
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Re: Technical name for a pushable hinge

Post by Gearoidmuar »

A Hinju Poosh?
Ayesha
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Re: Technical name for a pushable hinge

Post by Ayesha »

horizon wrote:Thanks landsurfer - I presume the QR mechanism is also therefore an over centre lock.


No, its a "Cam operated clamp".

http://www.wdsltd.co.uk/products/Standa ... embly-650/
stoobs
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Re: Technical name for a pushable hinge

Post by stoobs »

Buuuuuut....while the clamping force comes from the cam operation, the clamp stays in position by going over (past) the centre (as can be seen by the shape of the cam on the handle side of the cam in the piccie)
Ayesha
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Re: Technical name for a pushable hinge

Post by Ayesha »

stoobs wrote:Buuuuuut....while the clamping force comes from the cam operation, the clamp stays in position by going over (past) the centre (as can be seen by the shape of the cam on the handle side of the cam in the piccie)


Yup, the QR cam has a flat that effectively locks the closure. What stops it vibrating open is the tension in the skewer.
mrjemm
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Re: Technical name for a pushable hinge

Post by mrjemm »

I don't see a flat on that. Doesn't even look like a reduction in radius. Fine tolerance if there is any.
A constant radius? Which would mean skewer tension and friction.

Can only google pics at mo, but they always look and feel like this to me.

http://s.wiggle.co.uk/images/hope-skewers-zoom.jpg

See a flat or radius reduction? Maybe it's cos I use the dreaded "outer cam" type that Mr S. Brown derided...
Ayesha
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Re: Technical name for a pushable hinge

Post by Ayesha »

Why argue the toss about something that indisputedly works?
Master6
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Re: Technical name for a pushable hinge

Post by Master6 »

May I answer the question with a question please?

Why does the OP, horizon, ask?
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531colin
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Re: Technical name for a pushable hinge

Post by 531colin »

Another domestic over centre lock is the clasp at the end of braces. (For holding up your riding longs.)
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horizon
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Re: Technical name for a pushable hinge

Post by horizon »

Master6 wrote:May I answer the question with a question please?

Why does the OP, horizon, ask?


Good question and thank you all by the way for the replies. I was looking at horizontal spacer flags (a long standing obsession of mine) and was looking at the need to be able to flick the flag into the vertical or longways position when riding through narrow spaces. Whatever this hinge thingy is called is the thing that would do it! There is already a spacer on the market that does this but it isn't quite what I want.
When the pestilence strikes from the East, go far and breathe the cold air deeply. Ignore the sage, stay not indoors. Ho Ri Zon 12th Century Chinese philosopher
stoobs
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Re: Technical name for a pushable hinge

Post by stoobs »

mrjemm wrote:I don't see a flat on that. Doesn't even look like a reduction in radius. Fine tolerance if there is any.
A constant radius? Which would mean skewer tension and friction.

Can only google pics at mo, but they always look and feel like this to me.

http://s.wiggle.co.uk/images/hope-skewers-zoom.jpg

See a flat or radius reduction? Maybe it's cos I use the dreaded "outer cam" type that Mr S. Brown derided...


I can't see a flat on it either. And the radius would not have to reduce if its centre is not the centre of rotation, no? But it could still go over-centre. One of the tech drawings shows 2 centres if I'm not mistaken, but does not show where those centres are in the other plane!
singer
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Re: Technical name for a pushable hinge

Post by singer »

you've got one half way down each leg, it's called a knee!
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