What is this?

Called a tachograph. There is a round card that goes into it and records the speed of the truck. Very common in the 50,s 60's and 70's. Sorta like a prehistoric big brother before computers.

 

Yep, I remember seeing those. Old "tachograph".
That was the "old tech" version of today's electronic 'logging'. lol
They were made by Sangamo mainly (also known for manufacturing your utility company's electric meters).

Like mnmover said, it had a revolving paper disk inside that a pen needle "scratched against", recording your speed (or rpms) over a 7 day period, IIRC.
I'm glad mnmover said the name of it, because I knew what it was, but was sitting here scratchin my head trying to recall the NAME of it.

 

Used those for many years...there are 3 scratch awls inside, they record time,speed and rpm's, they could be a daily or a weekly time clock, and the clock is/was a windup with a key type. Or if it was a union shop the mechanic's or safety dept would load it and lock the door so the driver wasn't able to mess with it.

 

You could use a cigarrette butt and block the speed off at 55 but usually get caught cause it would draw a straight line.

 

man. I remember these from back in the 80's.

 

Don Keith out of Bakersfield Ca used to have them years ago. Old kenworths hauling crude oil

 

peterbilt_2005,

At first, my eyes popped wide open when I saw the recorded speed read "90", (thinking mph). I said to myself "Whoa".
Then I noticed the disk was actually recorded in kilometers per hour.

Side note: The recorded 90 kph = 56 mph

 

We had them up through the 90's. Believe it or not they have companies that read the chart for the company and gives a report on how the driver was driving. They are very accurate if not broken up. They can tell if the truck swerved or came to a fast stop just about all the information that is needed when the truck is in an accident. It can either save the driver or hang'em. Of course nowadays there's better devices to record the history but back in the day these were very rugged and reliable. They also had many ways to cheat the system too.