Patent ID: 8757868

Claim:
A method of fabricating a timepiece balance spring assembly in micro-machinable material or silicon and in three dimensions, including at least a first flat component formed by a hairspring in micro-machinable material or silicon made in a wafer of micro-machinable material or silicon with a given crystalline orientation, said first component extending on one side from a base plane, wherein the method comprises: breaking down the volume of said balance spring assembly into elementary volumes, respectively inscribed in elementary parallelepiped prisms, said elementary prisms being secant at least in pairs to a junction area, said elementary volumes being perpendicular to each other and forming the same number of sub-components, each made in a wafer of micro-machinable material or silicon determined by the thickness and crystalline orientation thereof, each said wafer extending parallel to a wafer plane between two main parallel faces of the wafer; making at least one of said sub-components to form an outer curve of said balance spring assembly, directly joining said at least one hairspring at a point in space, the projection of which into said base plane is located external to said hairspring, said outer curve being in an orthogonal plane to that of said at least one hairspring; and assembling said sub-components at said junction areas by assembling means.