M & W DR961 Micrometer

Can anyone help?

I have a Moore and Wright DR961 0 – 1” micrometer.

This is a direct reading mechanical as opposed to electronic mechanism. It reads to 0.0002” with the thou’s showing as numbers in the viewing window in the thimble.

This is a favourite micrometer of mine due to the direct reading so I was upset when it fell out of my overall coat pocket when I picked up the coat to put it on. The micrometer fell onto a concrete floor with the result that the thimble sprung off the knurled operating knob. After a lot of attempts I have managed to relocate the thimble back in the correct location. The direct reading figures and graduations are correctly located within the transparent window in the thimble. Unfortunately when the thimble with the attached spindle is screwed back into the body of the micrometer and the thimble located at either the “0” or the “10” graduation on the body the spindle is exactly 0.030” clear of the anvil or 1.030” (using a 1” test disc from my M & W 0 – 4” micrometer set) at “0” and “10” respectively. After weeks of trying I cannot find what is wrong. The thread is 50 TPI with one revolution moving the spindle 0.020” . It looks to me that the spindle need extracting 0.030” from the knurled operating knob. But how? Just short of where the spindle ends and becomes the threaded part of the component there are two black areas. One about 1/16” wide and the other 1/32”. If this should be a join where the spindle is threaded to the operating thread it should be possible to add shims to extend the length by 0.030”. But again how?

I have contacted Bowers Group who have Moore and Wright as one of their companies. A Mr Alex Glover Repairs & Calibration Manager (in-house lace w:st="on">UKlace>) e-mailed me to say “Unfortunately we don’t have literature for these mics, due to their age and update of our electronic drawings / system. I’m sorry, I’m unable to help in this instance”.

If anyone on the forum can help I would be extremely grateful

Regards,

Wychwar

There is a metric version on Ebay at the moment and it quotes a British paten number BRIT.PAT.1158293 which may give a clue -- might have look tomorrow too late right now !

John

.

Allow me, John

... You’ve done the difficult bit already

**LINK**

https://worldwide.espacenet.com/publicationDetails/originalDocument?CC=GB&NR=1158293A&KC=A&FT=D&ND=3&date=19690716&DB=EPODOC&locale=en_EP

MichaelG.

Well done Michael, hopefully this will help Roger to figure out how to "time" the micrometer

John

To resurrect an old thread, does anyone have any experience of these micrometers?
I've downloaded the patent, and having a read.

I recently picked up one second hand, which seems to need a bit of "adjustment", so I though I'd enquire here first, before I risk damaging anything.

Bill