GB1344647A - Sealed watch case with leakage indicator - Google Patents

Abstract

1344647 Watches A SCHOLLER and E BANDELIER 8 Dec 1971 [10 Dec 1970] 56913/71 Addition to 1307415 Heading G3T In a sealed watchcase which is normally under pressure or vacuum and has a leakage indicator comprising a deformable membrane having one surface subjected to the pressure in an enclosure sealed off from the inside of the watchcase by the membrane and its other surface subjected to the pressure inside the case, an observation aperture is provided through which a part of the membrane or a signalling member carried or actuated thereby becomes visible or invisible in the event of a leak. Fig. 6 shows an indicator comprising an opaque enclosure which is fitted in a watch glass 19 and contains a membrane 12. The membrane 12 is spaced away from screen 13 and invisible so long as the interior of the watchcase is under vacuum. If vacuum is lost, the membrane 12 is deformed so that a coloured patch thereon becomes visible through aperture 14. A main outer watch glass is additionally provided. The space between the two glasses may form part of the sealed enclosure Fig.7 (not shown) or the outer glass may be omitted Fig. 5 (not shown). Alternatively, the indicator may be fitted on a watch dial and comprise a diaphragm (8), Figs.3 and 4 (not shown) having a slit (10) which is normally closed but becomes opened to form the observation aperture when the diaphragm (8) is deformed by the membrane. In further embodiments, a part of the membrane becomes deformed to bulge through the observation aperture Figs.8 and 9 (not shown) or is used to actuate a mechanical indicator (36), Fig.10 (not shown).