| 摘要 |
The watch case including a back cover, a caseband, a crystal, the peripheral zone of which entirely covers the caseband, a casing ring including at least one packing, a pair of supports facing one another fixed to the caseband and forming therewith a slot in which the crystal may be engaged and means for displacing the casing ring in order to compress the packing against the internal surface of the crystal and block said crystal against the supports. The crystal exhibits at least in its peripheral zone a spherical form of constant thickness. The upper surface of the caseband has the form of a part of a sphere the radius of which is substantially equal to that of the internal surface of the crystal. During assembly the internal surface of the crystal is made to slide over the upper surface of the caseband with a rotational motion resulting from the sliding of a spherical surface over part of a sphere.
|
