Need help identifying this circular slide rule

Stephen!

Flivver Flyer
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#1
Apparently the company that made this started life as a clock maker in the UK so I figured I would take a shot at one of y'all being able to identify this. Seems to be some kind 7-Day "analyzer" with two scales. One linear and one non-linear. (That crooked line on the clear piece is a scale, not a crack)



 

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Owsley

Premier Member
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#3
I didn't look up tachograph, so is that the correct answer?

If not I can send it to my clock guy and see if he knows.
 

Stephen!

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#4
A tachograph appears to be the 1920s rotary paper card version of the ELD the truckers love so much these days.

"A tachograph is a device fitted to a vehicle that automatically records its speed and distance, together with the driver's activity selected from a choice of modes."

Looks like Colin could have the answer.

I would really like to learn how to use this thing but I keep coming up empty on my searches. :confused:
 

EddyC

IBA Member
#7
A "normal" tachograph card is a 24h card. It is to register, amongst other things, the time the vehicle was moving, the kind of activity was exercised, the speed of the vehicle and, last but not least, how many hours the driver was actually driving.
The point of being a 24h card was to have control of the restricted driving time and the remaining resting time during that period and in relation to the previous period of 24h. There are similar devices as shown in the pictures above, but of course for 24h cards.
So I agree with Tom Tom it is not a tachograph reader, at least not for an "official" tachograph card.
Good luck on the search..
Ed.
 
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Stephen!

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#10
Don't think it's a tachogragh reader this is the type when I was driving.
https://www.worthpoint.com/worthopedia/vintage-chart-analyzer-sangamo-3847647510
That was the ONLY site I could find in my search that showed something looking like this one. It seems to be a weird site, though. The only description given is just the information found on the device itself...
Does not say what it actually is in the description. Almost like it was built by a bot crawling through old eBay listings.

The one you have seams to be something to do with electric meters.
https://www.worthpoint.com/worthopedia/vintage-chart-analyzer-sangamo-3847647510
But I could be wrong
That is the same link.
 

Stephen!

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#13
Saw some 7 day charts fitted to freezers to record temperatures over a week.
There are still some out-of-the-way places still using those. If you look around at some of the older rural Mom 'n Pop stores you can still see them occasionally.

Near as I can tell, this device's wheels are not intended for recording. There is no "vertical" scale. I am sure it is a conversion calculator of some kind, given the two lines on the overlying transparent piece.
 

GSears

Dambuster... Bouncing panniers...
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#15
It is possible the device may be used to read/analyse the chart. To check if temperatures have dropped or risen above predetermined levels.

Scales on the chart aren't radial. (curved).

If I remember correctly (it was a long time ago) the recording needle arm was pivoted to the left of the recording unit which resulted in a curved trace for a change in temperature on the chart. Hence the need for a curved scale.

The analyser you have would be to help read the chart.
 
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