Patent Publication Number: US-7708457-B2

Title: Watch with a polygonal bezel

Description:
This application claims priority from European Patent Application No. 07101333.8, filed Jan. 29, 2007, the entire disclosure of which is incorporated herein by reference. 
   FIELD OF THE INVENTION 
   The present invention relates to the field of horology. It concerns more specifically a watch including a middle part on which a polygonal bezel of soft or fragile material is mounted. 
   “Soft material” means a material having a Vickers hardness of less than 30 HV for example wood, certain plastics or even leather. “Fragile material” means a material with no plastic deformation field, such as a ceramic, stone or mother of pearl. More generally, the group of soft or fragile materials is substantially formed of non metallic materials. 
   BACKGROUND OF THE INVENTION 
   Watches comprising an exterior made of soft material, such as wood, are known to those skilled in the art for their particularly decorative appearance. In existing embodiments, the case is either entirely formed of wood, or formed of a metal body covered with a wooden cover. Reference can be made, for further information about these embodiments, to Patent Application Nos. DE 233 309 and CH 667 177. 
   One drawback of the exterior made of soft material is its lack of resistance to wear. Since angular parts, such as corners, are particularly exposed to wear, existing embodiments do not include any, but have rounded shapes. Such watches are consequently limited to circular and oval geometries. 
   Watches whose exterior is formed of a fragile material are also known. Unlike soft materials, fragile materials are generally quite resistant to wear, but are liable to break at the angular parts. For this reason, circular and oval geometries are also preferred for watches comprising an exterior made of fragile material. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to overcome these limitations, by proposing a watch fitted with a polygonal bezel made of soft or fragile material, whose corners are resistant to wear and shocks. 
   More specifically, the invention concerns a watch comprising a middle part including a top face arranged for receiving a polygonal bezel made of a first material, characterized in that the corners of the bezel are truncated and in that the middle part is fitted with angular elements made of a second material secured to the top face thereof and arranged to be substituted for the truncated corners of the bezel when the latter is mounted on the middle part. 
   In a particularly advantageous embodiment, the second material is more resistant to shocks or wear than the first. 
   Owing to the angular elements made of a shock or wear resistant material, arranged to be substituted for the corners of the polygonal bezel, any wear or breakage of the corners, which are the major drawbacks of such a bezel, are greatly reduced. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other features and advantages of the present invention will appear more clearly from the following detailed description of an example watch according to the invention, this example being given purely by way of non limiting illustration, with reference to the annexed drawings, in which: 
       FIG. 1  is a perspective view of the watch according to the invention; 
       FIG. 2  is a cross-section of the case along a first axis AA, and 
       FIG. 3  is a cross-section of the case along a second axis BB. 
   

   DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS 
   The watch shown in  FIGS. 1 ,  2  and  3  includes in a conventional manner a case  10 , formed of a middle part  12 , a back cover  14  and a bezel  16 . Middle part  12  defines with back cover  14  a housing  18  containing a movement  20 . Movement  20  can be of the mechanical or electromechanical type powered by a battery that is not shown. The watch further includes a crystal  22  mounted on middle part  12 , a dial  24  inserted between the movement  20  and crystal  22 , and time indication display means, such as hands  26  and  28 , kinematically connected to movement  20 . A crown  30 , secured to a winding stem, located on the side of middle part  12 , is for winding and correcting the time indication. 
   Middle part  12 , back cover  14  and bezel  16  have a substantially square geometry. In a variant, middle part  12 , back cover  14  and bezel  16  could be of any polygonal shape, for example, rectangular, hexagonal, triangular, etc. Middle part  12  and back cover  14  are formed of a material that resists wear and shocks well, typically a metal, such as steel. The bezel is formed of a soft or fragile material, such as wood, ceramic, mother of pearl or any other non metallic material able to provide a decorative effect. 
   Middle part  12  includes a top face  32  formed of a substantially plane surface  34  delimited by an inner edge  36  forming a shoulder  38  on which crystal  22  is mounted. Those skilled in the art could choose to mount crystal  22  in a water resistant manner, by inserting a sealing gasket between crystal  22  and middle part  12 . The top face  32  further includes four angular elements  40   a, b, c  and  d , which project relative to surface  34  and are arranged at the four corners thereof. The four elements  40   a, b, c  and  d  form with middle part  12  a monoblock assembly. They are obtained by machining top face  32 , or by stamping middle part  12 . In a variant, elements  40   a, b, c  and  d  could be added to middle part  12  by brazing, welding, bonding or by screws. 
   Bezel  16  is positioned on the top face  32  via an edge  36  and screwed to middle part  12  using four screws so as to be pressed against surface  34 . In a variant, bezel  16  could be bonded to surface  34 . The four corners of bezel  16  are truncated, such that when it is positioned on top face  32  of middle part  12 , angular elements  40   a, b, c  and  d  take the place of the four corners. This arrangement prevents the corners of bezel  16  being damaged, either by wear or by a shock. 
   Thus a watch has been described including a polygonal bezel whose corners resist wear and shocks well. It goes without saying that the present invention is not limited to the embodiment that has just been described, and that various simple alterations and variants could be envisaged by those skilled in the art, without departing from the scope of the present invention as defined by the annexed claims.