H & K were the UK agents for Wohlhaupter if I recall correctly. Now a shadow of their former glory being no less than a logistics company I believe. They were based at Rugby and a lot of there 'goodies' were supplied to the BTH (latterly AEI but again now a multitude of car exhaust and tyre centres plus innumerable Tanning Studio's ) works there manufacturing turbines for power stations.

Bev – A bit of a background of where your cousin may have picked up such a tool may be helpful, where did he live? what major industries were in his area? Could be a start to finding where it may have come from. Are there any other markings on it? which could give a clue to where it was used (R or RR usually indicates Rolls Royce for instance, AS = Armstrong Siddeley, CT = Courtaulds Textile, etc,. )

Martin

My money's on this being a peculiar indicating mic.

The features that it has in common with regular ones is the angled rod for limiting how far you can shove each part in the throat of it, the spring loaded measuring element and the +/- scale that seems to be independent of the main scale.

Bev: Does anything move up and down the scale when you press the plunger?

Apologies … Not quite sure what happened there ^^^

Google ‘helpfully’ provided the URL for the referring page instead of the one I wanted to quote

[ Wizemann’s patent is ‘cited’ in that one ]

.

Try this: **LINK**

https://worldwide.espacenet.com/publicationDetails/biblio?CC=US&NR=4005686A&KC=A&FT=D

MichaelG.

Edited By Michael Gilligan on 29/07/2021 09:07:59

Having relieved Bev of his micrometer … I have removed the barrel for investigation

The knurled thimble moves things bodily within the confines of this flat:

.

and the sprung scale at t'other end looks like this:

.

There is [as Bev has already noted] no apparent connection between this and the anvil

I suspect that things in the anvil area are gummed-up with hardened grease.

… We shall see

MichaelG.

A quick update :

Predictably enough, the dark spot in the screw-thread was grease, concealing a slotted screw.

… it appears to be very tight, so I am leaving it be for a while.

MichaelG.

It doesn't help with the ID, but it's not unique.
https://www.kenosha-reuse.com/ZION,-IL/Commercial/Mechanical/Refurbished/No-Warranty/Rare-german-mystery-micrometer-hahn-kolb.cfm

Bill

Hey, I just finished restoring a similar Jsameter and this thread helped a lot with finding additional information so I just wanted to share what I found out.

The Jsameter is an adjustable snap gauge, how it works: Depress the plunger to retract the anvil, insert the part and let go of the plunger – the springs can only push the anvil forward until it touches the part and the plunger stops and shows a reading on the scale:

The mechanism is quite interesting, on the inside there is a very slightly tapered pin the length of the measuring range and connected to the plunger, it rides between 7 loose bearing balls so be aware when opening one of those up. The plunger is spring-loaded and pushes the bearing balls apart which rest inside a cone that is connected to the anvil – the balls move outward and push the cone forward – the anvil moves forward. Depressing the plunger lets the anvil move back/open up with the help of another spring.

The end part of the barrel with the measuring line on it is pressed in, there are no screws and only two small ridges to pull on. I took out the scale and used parallel pliers on the flat part with the line to wiggle it out with the barrel in the vise with copper jaws. After getting it out I immediately spilled the bearing balls on the floor

My idea of the origin of the name – there is a dial snap gauge called the Passameter, maybe this is the Passameter from J Weco – the Jsameter.

I was also able to find a patent from Wizemann showing the exact instrument in the drawings, except in the patent it is a thread gauge. The patent is from 1939: espacenet: Patent CH236608A

But the mechanism might be a little older, there is a patent from inventor Walter Wolff form 1931: espacenet: Patent DE601437C

Kristof