Patent Publication Number: US-6711886-B1

Title: Link members and a band formed of such link members

Description:
This invention relates to link members adapted to form bands, e.g. for watches and bracelets and the like, and a band formed of such link members. 
     BACKGROUND OF THE INVENTION 
     In metal watch bands formed of inter-engaging metal links, the links are usually made of a single relatively hard metal, e.g. stainless steel, in order to withstand wear and tear during use. A shortcoming associated with such conventional links is that such metal is usually expensive. It is also difficult to drill holes in the links for insertion of linking pins for connection purpose, thus making manufacture of such links costly, time consuming and difficult. 
     It is thus an object of the present invention to provide a link member and a band formed of such link members in which the aforesaid shortcomings are mitigated, or at least to provide a useful alternative to the public. 
     SUMMARY OF THE INVENTION 
     According to a first aspect of the present invention, there is provided a link member adapted to form a band, said link member including an outer casing formed of a plate made of a first metal, and an inner part made at least of a second metal, wherein said first metal is stainless steel or titanium, and wherein said second metal is aluminum, zinc, an aluminum alloy, or a lead alloy. 
     According to a second aspect of the present invention, there is provided a band including a plurality of link members inter-engaged with one another, wherein at least one said link member includes an outer casing formed of a plate made of a first metal, and an inner part made at least of a second metal, wherein said first metal is stainless steel or titanium, and wherein said second metal is aluminum, zinc, an aluminum alloy, or a zinc alloy. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the present invention will now be described, by way of examples only, with reference to the following drawings, in which: 
     FIG. 1 is a side view of a first watch band made of inter-engaging links according to the present invention; 
     FIG. 2 is a top view of the watch band shown in FIG. 1; 
     FIG. 3 is a perspective view of a first link according to the present invention, and forming part of the watch band in FIG. 1; 
     FIG. 4 is a perspective view of a second link according to the present invention, and forming part of the watch band in FIG. 1; 
     FIG. 5 is a side view of a second watch band made of inter-engaging links according to the present invention; 
     FIG. 6 is a top view of the watch band shown in FIG. 5; 
     FIG. 7A is a cross sectional view of a third link according to the present invention taken along the line A—A in FIG. 6; 
     FIG. 7B is a perspective view of the third link shown in FIG. 7A; 
     FIG. 8A is a cross sectional view of a fourth link according to the present invention taken along the line B—B in FIG. 6; 
     FIG. 8B is a perspective view of the fourth link shown in FIG. 8A; and 
     FIG. 9 is a perspective view of a fifth link according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1 and 2 show, respectively, a side view and a top view of a first watch band, generally designated as  100 , made by linking up a number of links  102 ,  104  according to the present invention. A number of the links  102  are connected by stainless steel pins (not shown) to form chains of links  102  in which the links  102  are movable relative to one another. One of the links  102  is connected with the link  104 , which is in turn connected to a buckle  106 . All such connections are made possible by stainless pins (not shown), whereby the various links  102 ,  104  and the buckle  106  are movable relative to one another. 
     Turning to FIG. 3, such shows a perspective view of the link  102 . The link  102  is made of an outer casing  112  made of titanium or stainless steel. The casing  112  is formed by bending a suitably shaped titanium or stainless steel plate into the shape and configuration as shown in FIG.  3 . The titanium or stainless steel plate may be of a thickness of around 0.5 mm, although it should be understood that such may be of some other thickness. Housed within the casing  112  are two plates  114  made of aluminum or an aluminum alloy comprising at least 90 wt. % of aluminum. The alloy may include magnesium or, additionally, manganese. 
     A number of channels  116  are provided in the plates  114  and the casing  112 . As aluminum and aluminum alloys are softer than titanium or stainless steel, it is easier to provide such channels  116 , than if the whole link  102  is made of titanium or stainless steel. A stainless steel pin (not shown) may be received within aligned channels  116  to connect adjacent links  102 ,  104 . It can also be seen that at least two outer side surfaces of the links  102 ,  104 , of which only a respective one  118 ,  120  is shown in FIGS. 3 and 4, are covered by the outer casing  112 . 
     A potential difference will develop because of the contact between the titanium or stainless steel casing  112  and the inner aluminum or aluminum alloy plates  114 , as a result of which the inner plates  114  will suffer from sacrificial corrosion. As the metal forming the casing  112  will experience corrosion, e.g. oxidation, at a lesser rate than when it stands alone, e.g. in conventional links made of titanium or stainless steel alone, its surface texture, e.g. brightness, can remain intact for a longer period of time. In order, however, to lessen the rate of sacrificial corrosion of the inner plates  114 , the aluminum or aluminum alloys may first undergo oxidation to reduce the resultant potential difference between the casing  112  and the plates  114 . 
     FIGS. 5 and 6 show, respectively, a side view and a top view of a second watch band, generally designated as  200 , made by linking up a number of links  202 ,  204 ,  206  according to the present invention. A number of the links  202  and  204  are connected by stainless steel pins (not shown) to form chains of relatively movable links  202 ,  204 . The link  206  is connected with a buckle  208 . All such connections are made possible by stainless pins (not shown), whereby the various links  202 ,  204 ,  206  and the buckle  208  are movable relative to one another. 
     FIGS. 7A and 7B show different views of the link  202 . The link  202  includes an outer titanium or stainless steel casing  210  surrounding and contacting two inner plates  212   a ,  212   b  made of aluminum or an aluminum alloy. The casing  210  is formed by bending a suitably shaped plate. Two channels  214  are formed between the two inner plates  212   a ,  212   b , allowing insertion of a respective stainless steel pin (not shown). 
     As to FIGS. 8A and 8B, such show, respectively, a sectional view and a perspective view of the link  204 . The cross-sectional shape of the link  204  is similar to a letter “H”, and its titanium or stainless steel outer casing  216  contains two aluminum or aluminum alloy plates  218   a ,  218   b , between which two channels  220  are formed. The channels  220  are aligned with apertures  222  formed on two outer side surfaces  223 , of which only one is shown in FIG. 8B, of the link  204  for forming two continuous holes, each for receiving a stainless steel pin (not shown) for joining the link  204  with two links  202 , one on each side of a bridging portion  224  of the link  204 . FIG. 9 shows a perspective view of the link  206  for connection with the buckle  208 . 
     Although it is described and shown here that two plates  114 ,  212   a ,  212   b ,  218   a ,  218   b  of aluminum or aluminum alloy are housed in the respective casing  112 ,  210 ,  216 , it should of course be understood that the inner part of the casing  112 ,  210 ,  216  may be housed with different number of, e.g. one, three or four, such plates  114 ,  212   a ,  212   b ,  218   a ,  218   b . It should also be noted that the plate(s)  114 ,  212   a ,  212   b ,  218   a ,  218   a may also be made of zinc described in the context of separate embodiments, may be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any appropriate sub-combinations.