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Why convex/curved glass for gauges?

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HerronScott

HerronScott

Darth Vader
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Does anyone know why convex/curved glass was used for the gauges in early Triumphs? Did all British cars of that era use convex glass?

Just curious!

Scott
 
I would assume that it was used to cut down on glare and reflections.
 
Good question Scott. I suspect it has something to do with glare coming off flat lenses. I'm sure that by the end of the day we will have a definitive answer.

Tinkerman
 
Just my two cents worth but, it could have been a cost reduction, as curved lenses cost twice as much as flat glass. PJ
 
I don't know of any other British cars in my limited knowledge, that have convex glass.
 
Ok, here is the real reason. Triumph didn't know how to make flat glass so they used up what they had. Or is it because there is so little light in the gauge that you need all the help you can get to see it in the dark. Sorry, I had to say it.
 
tomshobby said:
I had a '62 TR4 with convex glass on the gauges.
Click to expand...
Mine still does. I even retrofitted the curved glass into a Smith's voltmeter I installed in place of the Ammeter.
 
tomgt6 said:
Ok, here is the real reason. Triumph didn't know how to make flat glass so they used up what they had. Or is it because there is so little light in the gauge that you need all the help you can get to see it in the dark. Sorry, I had to say it.
Click to expand...

TexasKnuckhead said:
Maybe because water drips off better from a curved surface?
Click to expand...

:lol:

Scott
 
Early TR4's had the same curved glass in their guages as TR3A's, including the new electric temp guage.

The glass became flat when TR4 guages were changed to having a shroud over the needle, which concentrated night back lighting onto the measurement scale instead of the whole guage.

I believe the curved glass was a means of cutting reflections on the speedo, and used on the other instruments for the sake of uniformity.

Viv.
 
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