tipsy keyn. a kind of watch-key invented by Bréguet: see quot. 1884.
ΚΠ
1884 F. J. BrittenWatch & Clockmakers' Handbk. (new ed.) 36Tipsy Key, a watch key in which the upper and lower portions are connected by means of a ratchet clutch kept in gear by a spring, so that the upper part will turn the lower part in the proper direction for winding.