Well, I'm shocked.

Wha'? Whoosh?

 

Not you, you fool.

 

Surely the increase in velocity is caused by a pressure drop?

 

My money goes on the boy Carley if this one starts to run...

 

This keeps on coming up and last time I spent ages on Google Patent
Search trying to find the patent Ford supposedly has. I can't - can you?

Ford do have a trademark on "QuickClear" but that's a different thing
altogether. I have a suspicion that the reason other manufacturers don't
use it is that the windscreen replacement gets tiresomely expensive.

 

Agreed, I did A level physics 47 years ago so he is a tad more up
to date than me.

Mumbles incoherently about partial vapour pressures and gives up.

 

<cough> It was posted here yesterday...
http://www.freepatentsonline.com/4743741.html
Message-ID: <>

 

URL:http://en.wikipedia.org/wiki/Bernoulli's_principle#Real_world_application

 

He's even got his own wind tunnel!

 

Yes - http://www.google.com/patents/about?id=7Qo-AAAAEBAJ

 

That isn't it.

 

So have I after last night's curry.

 

Cheers! So it's obviously expired now since it was issued in 1975.

 

Of course, you could have just used the one I posted yesterday
http://www.freepatentsonline.com/4743741.html which actually lists
Ford as the assignee.

 

Except that the later one I quoted (again, at
http://www.freepatentsonline.com/4743741.html) was issued in 1988.
This one specifically covers windscreens "having a complex curved
configuration".

So it is perhaps a sign of the very recent expiry of this patent (in
most cases it's 20 years, in some, like Germany, it's only 18) that
VW's now have this feature, and it's possible that other makers now
do. Who else has bought a brand new car in the last year or so?

 

AFAIK, the only system Ford have used is the one I linked to with
hundreds of tiny wires embedded in the glass. I'm not aware of anyone
using the conductive coating method in your link, but I'm not remotely
up on recent cars.

 

How do you know?

It seems to fit the known facts better, in that it would have expired
last year, or possibly two years earler in Germany, hence we're now
seeing these screens offered by other manufacturers.

Only if you click to open it (as I realised after I posted).

 

Ah. Ignore my other post then.

The VW one appears, when examined closely, to have a sort of
pixellation effect, which might be consistent with
non-visible-to-the-eye wires embedded, rather than a coating, although
of course said coating would presumably have been placed within the
laminate, so may have some visual effect in itself.

But assuming it is wires, why would the 1975 Patent have stopped other
makers using this stuff up until so recently?

I know that a couple of people are claimiing to have seen them on cars
many years ago, but they certainly have not been available on modern
cars in recent time, and I'm sure they would have been very common had
they been so available.

 

Indeed - and it was a much cruder system, stuck onto the glass in a
similar way to normal heated rear windows.

The Monte Carlo rally Minis used a version of it, back in the '60s.