Recent discussion on oddball micrometers sent me to my 1930s(?) Shardlow micrometer catalogue (Ambrose Shardlow & Co, Sheffield).
This one opens fully with one turn of the thimble, and automatically closes when released. Full explanation in the text.
I don't know how it worked out in practice. Shardlow had some interesting ideas, including the 'Mizzy' direct reading micrometer, the 'check reading' micrometer, and the combined inch/metric mic, all of which I think I've posted about in the past. The ideas looked good on paper.