Method for manufacturing articless of jewellery

Abstract

Method for manufacturing an article of jewellery, which comprises a step involving manufacture of a first hollow element in tubular form, said element being made of precious metal or a precious metal alloy and intended to act as a lining; a step involving preparation of a second tubular element made of metal or metal alloy and intended to act as a core for said first element in tubular form; a step involving coaxial joining together of the two elements by means of arrangement of a layer of solder in between so as to obtain a tubular assembly which is then subject to a first drawing step aimed at compressing the first element onto the second element; this is then followed by a step involving brazing of the tubular assembly so as to melt the layer of solder and fix together the two elements before a second drawing step for reducing the thickness of the brazed tubular assembly to the desired value.

1 . Method for manufacturing an article of jewellery, comprising the following operating steps: 
 a step involving manufacture of a first hollow element in tubular form, said element being made of precious metal or a precious metal alloy and intended to act as a lining;    a step involving preparation of a second tubular element made of metal or metal alloy and intended to act as a core for said first element in tubular form;    a step involving coaxial joining together of said first element and said second element by means of arrangement of a layer of solder in between so as to obtain a tubular assembly;    a first drawing step involving drawing of said tubular assembly, intended to compress said first element onto said second element;    a step involving brazing said tubular assembly following said first drawing step so as to melt said layer of solder and fix together said first element and said second element;    a second drawing step performed after said brazing step, for reducing the thickness of said brazed tubular assembly.    
   
   
       2 . Method according to  claim 1 , in which said joining step is performed during said step involving manufacture of said first element in tubular form, which manufacturing step envisages a step for forming said first element in the form of an open channel with a substantially U-shaped cross-section from a sheet-like strip, a step involving insertion of said second tubular element inside said U-shaped channel and a step involving closing said U-shaped channel with said second element inside.  
   
   
       3 . Method according to  claim 2 , in which said closing step envisages continuous welding on said first element in a longitudinal direction of closing of the adjacent edges of said U-shaped channel.  
   
   
       4 . Method according to  claim 1 , in which said joining step is performed after said step involving manufacture of said first element in tubular form and consists in coaxial insertion of said second tubular element inside said first tubular element.  
   
   
       5 . Method according to  claim 4 , in which said step of manufacturing said first element is performed by means of continuous extrusion casting.  
   
   
       6 . Method according to  claim 4 , in which said step of manufacturing said first tubular element envisages a forming step in which said first element is transformed from a sheet-like strip into the form of a tube by passing through pairs of pressure rollers arranged in sequence.  
   
   
       7 . Method according to  claim 6 , in which said step of manufacturing said first element is followed by a step involving continuous welding on said first element in a direction of longitudinal extension of the latter so as to close together the adjacent edges of said first element following its deformation into a tubular form.  
   
   
       8 . Method according to  claim 1 , in which said layer of solder is initially arranged on one joining surface of said first element or said second element, which surface is intended to be interfaced with the corresponding joining surface of said second element or said first element, so that said layer of solder is arranged between said first element and said second element.  
   
   
       9 . Method according to  claim 8 , in which said layer of solder continuously lines the joining surface.  
   
   
       10 . Method according to  claim 8 , in which said layer of solder extends continuously over said joining surface in the axial direction of said tubular assembly and in a discontinuous manner along its circumferential extension.  
   
   
       11 . Method according to  claim 10 , in which said layer of solder is composed of one or more strip-like or filiform portions.  
   
   
       12 . Method according to  claim 8 , in which said layer of solder is applied to the joining surface of said first element before the step involving manufacture thereof in tubular form.  
   
   
       13 . Method according to  claim 1  in which said first element is made of precious metal chosen in particular from gold, platinum and silver or is made of an alloy of precious metal chosen in particular from a gold alloy, silver alloy or platinum alloy.  
   
   
       14 . Method according to  claim 1 , in which said second element is made of a metal chosen in particular from gold, silver, copper, titanium, aluminium, steel or alloys thereof.  
   
   
       15 . Method according to  claim 1 , in which said second element is in turn formed by a brazed tubular assembly obtained using said method.  
   
   
       16 . Method according to  claim 1 , in which said second tubular element is hollow.