A device is for fastening a back on a middle of a watch. The back includes a cover arranged to form a bearing surface with the middle and a body arranged to rest in the middle. The device includes a ring disposed between the back and the middle, the ring being arranged to ensure the water resistance and indexing of the back. The ring includes an upper part ensuring the water resistance and a median part including positioning to ensure precise placement of the back.

A water-resistant watch case of a diving watch, includes at least one back mounted on a lower side of a middle part, and a crystal mounted with a fastening gasket on an upper side of the middle part. The back includes an annular bearing surface for coming into contact with an inner annular surface of the middle part of a shape complementary to the bearing surface during mounting of the back on the middle part. The annular bearing surface and the inner annular surface are inclined towards the inside of the watch case at a determined angle less than 90 relative to a central axis perpendicular to a plane of the watch case so as to distribute stresses between the back and the middle part due to the water pressure during a dive. The annular bearing surface and the inner annular surface are conical in shape.

The invention relates to an anodic bonding method for bonding two elements with an intermediate layer. The invention especially, but not exclusively, relates to an anodic bonding method for between a metallic element and a heterogeneous element, for example a glass, artificial sapphire or ceramic element. The specificity and aim of the present invention is to produce an assembly that is gas-tight and fluid-tight, solderless, brazing- or welder-free and without organic compound (glue). The present method has multiple industrial applications, including making it possible to attach a watch-glass, typically made of mineral glass, sapphire or transparent or translucent ceramics, to a bezel or case middle of a watch case using the anodic bonding technique.

A back (1) for a watch case (50), the back (1) including a first element (10) arranged so as to be screwed onto the watch case (50), and a second element (20) including an end face bearing a pattern (M), the second element (20) being mounted such that it can move in rotation about an axis (C) passing through the centre of the case (50), wherein the second element (20) has a brake arranged so as to hold same relative to the first element (10) in different angular positions about the rotational axis (C), the brake being disposed between the first and second elements (10, 20).

A back (1) for a watch case (50), the back (1) including a first element (10) arranged so as to be screwed onto the watch case (50), and a second element (20) including an end face bearing a pattern (M), the second element (20) being mounted such that it can move in rotation about an axis (C) passing through the centre of the case (50), wherein the second element (20) has a brake arranged so as to hold same relative to the first element (10) in different angular positions about the rotational axis (C), the brake being disposed between the first and second elements (10, 20).

A mechanical or electromechanical timepiece including a watch case delimiting an internal volume, the watch case including a back delimiting the watch case at the bottom; a crystal closing the watch case at the top, the crystal defining a useful display aperture; a middle part connecting the back and the crystal to one another; a horological movement housed in the internal volume of the watch case; at least one hand for displaying information visible via a useful display aperture and rotated with respect to the watch case by the horological movement with at least one driving belt extending at least partially in the useful display aperture, the timepiece includes the internal volume of the watch case filled with a fluid wherein at least one driving belt is submerged, and wherein the driving belt is made of a material wherein the optical refractive index is equal or substantially equal to that of the fluid.

A mechanical or electromechanical timepiece including a watch case delimiting an internal volume, the watch case including a back delimiting the watch case at the bottom; a crystal closing the watch case at the top, the crystal defining a useful display aperture; a middle part connecting the back and the crystal to one another; a horological movement housed in the internal volume of the watch case; at least one hand for displaying information visible via a useful display aperture and rotated with respect to the watch case by the horological movement with at least one driving belt extending at least partially in the useful display aperture, the timepiece includes the internal volume of the watch case filled with a fluid wherein at least one driving belt is submerged, and wherein the driving belt is made of a material wherein the optical refractive index is equal or substantially equal to that of the fluid.

A watch assembly method includes: processing a first bonding surface on a first connecting member, bonding a first laser adhesive layer on the first bonding surface and activating the first laser adhesive layer; processing a second bonding surface on a second connecting member, bonding a second laser adhesive layer on the second bonding surface and activating the second laser adhesive layer; fixing the second connecting member with the first connecting member preliminarily in such a manner that the first laser adhesive layer and the second laser adhesive layer face each other, and pressing the first connecting member and the second connecting member against each other until the first laser adhesive layer and the second laser adhesive layer are completely bonded and infiltrated.

A watch assembly method includes: processing a first bonding surface on a first connecting member, bonding a first laser adhesive layer on the first bonding surface and activating the first laser adhesive layer; processing a second bonding surface on a second connecting member, bonding a second laser adhesive layer on the second bonding surface and activating the second laser adhesive layer; fixing the second connecting member with the first connecting member preliminarily in such a manner that the first laser adhesive layer and the second laser adhesive layer face each other, and pressing the first connecting member and the second connecting member against each other until the first laser adhesive layer and the second laser adhesive layer are completely bonded and infiltrated.

Disclosed herein is an electronic device. The electronic device includes a housing provided to accommodate a printed circuit board, a cover coupled to the housing, and including a coupling protrusion protruding to a side of the housing to be accommodated in the housing, and including a coupling hole formed in the coupling protrusion, a fastening pin arranged in the coupling hole and configured to couple to the housing, and a sealing member arranged between an inner wall forming the coupling hole and the fastening pin to seal the coupling hole. Various other embodiments are possible.