A device is for fastening a back on a middle of a watch. The back has a shoulder forming a cover arranged to cover entirely partly with the middle and a body arranged to rest in the middle. The device includes at least one pin integral with the middle, a seal mounted between the back and the middle. The back includes, near its periphery, at least one groove, the pin being arranged to slide in the groove between a first position, called the insertion position in which the back is free, and a second position called locking position in which the back is locked and positioned angularly relative to the middle. The groove includes at least one bump to form a hard point and increase the torque when the pin passes through the bump.

A closing/opening system for a case of a timepiece is defined particularly in first and second parts of the case. The system includes a device for producing a mechanical connection, particularly a bayonet connection between these first and second parts and a device for creating a friction torque between these first and second parts. The device for creating a friction torque includes tightening faces to cooperate with one another when closing/opening the case and which are defined in the first and second parts. The system further includes a tightening element in one of these two tightening faces. The tightening element generates a constant friction torque during a course of travel of one of the two parts relative to the other when closing/opening the case of the timepiece.

The invention concerns a timepiece member including a first axis and a first threading intended to cooperate with 5 a second threading provided on a second timepiece member. The first threading is configured so that a zone of contact between the first threading and the second threading extends over less than 50% of the height of the threads of the second threading or is configured so that the zone of contact between the first 10 threading and the second threading extends over less than 0.3 times the pitch of the threading.

A closing/opening system for a case of a timepiece is defined particularly in first and second parts of the case. The system includes a device for producing a mechanical connection, particularly a bayonet connection between these first and second parts and a device for creating a friction torque between these first and second parts. The device for creating a friction torque includes tightening faces to cooperate with one another when closing/opening the case and which are defined in the first and second parts. The system further includes a tightening element in one of these two tightening faces. The tightening element generates a constant friction torque during a course of travel of one of the two parts relative to the other when closing/opening the case of the timepiece.

A watch having a double watch-surface and a method for disassembling the double watch-surface are provided. The watch includes a casing, in which an abutting ring portion is convexly provided; a first watch-surface which is placed on the top of the abutting ring portion; a second watch-surface which is placed at the bottom of the abutting ring portion; an snapping ring, the inner ring of which is annularly provided with a pressing portion and a groove; and a transparent cover engaged onto the groove. The two snapping rings are respectively engaged with the top surface and the bottom surface of the casing. The snapping ring is disposed on the abutting ring portion through the plural engaging protrusions. The pressing portion is pressed against the first and second watch-surfaces. Through the adjusting and snapping assembly, effect of engaging and fixing the two snapping rings to the casing can be achieved.

A spring (1) for a notching system, the spring including at least two elastic arms (11, 12), and a first toothset javomg first notching teeth (11a, 12a) disposed on each of the arms, the spring being designed such that, in a position in which one of the arms of the spring is not loaded, the arm is convex as seen from the top of the first notching tooth of this arm.

A smart wristband with a rotatable dial has a dial, a case and a band. The case is embedded in the band. The dial is rotatably disposed in the case. An end of the dial is provided with a USB port, and the USB port is hidden between the dial and the case. The dial has a bottom case, a rotating ring is fixed at a bottom of the bottom case, the case is sandwiched between the bottom case and the rotating ring, and relative rotation between the dial and the case is achieved by the cooperation and relative rotation between the rotating ring and the case. An opening is provided at an end of the bottom case, a protruding buckling rib is provided at the other end, and a buckling groove that matches the protruding buckling rib is formed at the corresponding position of the case.

A convertible smart watch including: a frame having a groove; a watch body having an analog watch unit on one side and a smart watch unit on the other side leaning against each back, which is designed to be inserted to the groove; and a supporting member supporting the watch body so as to be rotatable, wherein one side is combined to the frame with a hinge such that watch body may rotate with respect to the frame between a first position being inserted to the groove and a second position being protruded to the front of the frame by leaving from the receiving groove.

In one embodiment, an apparatus includes a wristband adapted to position a watch face substantially over at least one of a lateral radial portion of a wrist of a user or an anatomical snuffbox of the user. In an example, this watch face may be part of a smartwatch or other personal electronic device.

A smart wristband with a rotatable dial comprises a dial, a case and a band. The case is embedded in the band. The dial is rotatably disposed in the case. An end of the dial is provided with a USB port, and the USB port is hidden between the dial and the case. The dial comprises a bottom case, a rotating ring is fixed at a bottom of the bottom case, the case is sandwiched between the bottom case and the rotating ring, and relative rotation between the dial and the case is achieved by the cooperation and relative rotation between the rotating ring and the case.