WRISTWATCH WITH FASTENING MEANS INSERTED ON THE EXTERNAL EDGE OF THE WATCHCASE Field of the invention

The present invention relates to the field of wristwatches. State of the art

It is known that a wristwatch essentially consists of three parts: the watchcase, the back case and the glass.

The watchcase is an essentially cylindrical hollow body, which accommodates the movement of the watch and is superiorly closed by the dial with the hands or by a display, in the case of digital watches; the crown and possibly one or more buttons or knobs which interact with the movement system by means of corresponding holes present in the edge of the watchcase and allowing the setting of the time and other possible functions of the watch (changing the date, stopwatch, etc.) are normally present on the external side edge of the watchcase. The back case closes the watchcase on the side opposite to the dial and allows access for cleaning operations, repairs, battery change, etc. The glass is the normally cap-shaped transparent part arranged to protect the dial. An elastic seal which ensures the sealing and the waterproofing of the watch is normally arranged between back case and watchcase and between glass and watchcase.

The back case and the glass are joined to the watchcase either by pressure or by fixing means, normally screws, arranged perpendicularly to the plane containing the watchcase and capable of engaging the appropriate cavities obtained for this purpose in the side wall of the watchcase itself. The pressure closing system is not particularly secure and is however certainly unsuitable for high-quality watches.

The closing system with the above-described fixing means, given the small dimensions involved, presents many problems; indeed, the use of a through screw capable of reciprocally engaging back case, watchcase and glass at the same time is not easy and requires particular contrivances and therefore two series of fixing means must often be employed: an upper one for joining the glass to the watchcase, and a lower one for joining the back case to the watchcase;

furthermore, the closing and opening of the fastening means thus arranged are not easy operations to be performed and furthermore the described position of the fastening screws may present problems also from the point of view of appearance. It is thus apparent the interest for a possible wristwatch wherein the fixing between the three essential component parts, as described above, does not present the aforesaid problems. Brief description of the figures

Fig. 1 shows a particular embodiment of the invention, with the fastening means respectively open (1 a) and closed (1 b) Figs. 2 (a) and (b) respectively show two embodiments of the invention Fig. 3 shows a further embodiment of the invention. Detailed description of the invention

The present invention allows to overcome the aforesaid problems in virtue of one or more fixing means arranged along the external wall of the watchcase. Specifically, either said fixing means may consist of means capable of rotating about their axis and acting on corresponding engagement means, integrally connected to the glass and to the back case perpendicularly to the plane which contains the watchcase, and of exerting an upwards or downwards traction orthogonal to the plane which contains the watchcase, or such fastening means may be traditional screws, in this second case the glass and the back case must be appropriately modified as shown below.

As shown in Fig. 1 , which depicts a specific embodiment of the invention, watchcase 10 presents fixing means along the external part comprising at least one pin 11 , in turn provided with cams 12 and 12' adapted to engage with one of corresponding counterparts 13, 13' integrally connected to glass 15 and to back case 14.

Obviously, by turning pin 1 1 , cams 12 and 12' will exert an equal and opposite traction on glass and back case thus sealing and fastening them to each other. According to a further embodiment of the invention, similar to the previous one, as shown in figure 2b, the fixing means consists of an essentially cylindrical body 16 on which the two ends of two tie-rods 17 are integrally connected, the opposite ends of which are integrally connected to back case and to glass, respectively;

obviously, by turning cylindrical body 16, the two tie-rods wind on it and pull glass and back case against the watchcase.

According to another embodiment of the invention, see Figure 2a, said essentially cylindrical body comprises a rack-type mechanism, in turn comprising a toothed wheel 16' capable of engaging toothed rods 17' integral with back case and glass so as to move them downwards and upwards as it rotates, thus fastening them. Similarly, pins provided with a protruding head capable of engaging the groove present on an essentially cylindrical body similar to above-described cylindrical body 16 may be integrally applied to the back case and the glass of the watch, in a direction orthogonal to the plane which contains them. As said cylindrical body rotates, said pins are pulled so as to fasten the concerned parts together. Appropriate safety mechanisms maintain glass, watchcase and back case fastened. For example, it may be contemplated that said cylindrical bodies may only rotate in one direction unless a release mechanism adapted to allow the rotation in opposite direction and the consequent opening of the watch is operated. According to a further particular embodiment of the invention, the fastening means consist of common screws inserted in the wall of the watchcase. According to this embodiment, diagrammatically shown in Fig. 2, both glass 15 and back case 14 are provided with an edge 18, consisting of an either continuous or interrupted cylindrical surface, arranged perpendicularly to the plane which contains them. The diameters of said edges will be reciprocally different and different from the diameter of the watchcase so that - when the wristwatch is being closed - they overlap and contain the watchcase. Said edges will be further provided with through holes 19 corresponding to threaded holes obtained in the watchcase. When the wristwatch is assembled, said holes will correspond and thus allow the insertion of appropriate screws 20 for fastening the various parts. The alignment of said holes for the insertion of the screw is facilitated by the presence of elastic seals. Obviously, the aforesaid solution is suitable for a number of similar variants according to the choice of the diameters of edges 18 of back case and glass which may be either smaller or larger than the diameter of the watchcase.

Instead of the traditional screws as described above, the watchcase, the back case and the glass may be joined by fastening means consisting of a "T"-tip screw comprising a spring.

In this case, the watchcase and edges 18 of glass and back case will present a slot capable of accommodating the T-tip of the screw then allowing the rotation thereof until it is arranged in an appropriate housing where it will be engaged in virtue of the traction action of the spring.