Master Dynamic Limited Patent applications |
Patent application number | Title | Published |
20140198627 | STRESS-RELIEF ELASTIC STRUCTURE OF HAIRSPRING COLLET - A hairspring collet for a hairspring for interference engagement and an interference fit with the cylindrical outer surface of the staff of a balance wheel for a timepiece movement, said hairspring collet portion comprising a plurality of circumferentially extending elastically deformable interconnected arm portions, the arm portions forming an annulus having a central axis and providing an aperture therebetween, wherein each arm portion including a curved concave engagement portion for engagement with the outer surface of a staff of a balance wheel, wherein each engagement portion has substantially the same radius of curvature as each other and are equally spaced from said central axis at a first distance and wherein said first distance is less than the radius of the staff of the balance wheel; said engagement portions have a radius of curvature such that upon deformation of the arm portions and engagement with the outer surface of said staff the engagement portions substantially conform with the outer surface of said staff and an interference fit is formed therebetween, wherein stress induced from said interference fit is transferred and distributed from along the engagement portions to the arm portions adjacent the engagement portions and distributed therein; and wherein the interference fit of the engagement portions with the staff substantially prevents relative movement between the hairspring collet and the staff of the balance wheel upon application of load from a hairspring in use in a timepiece movement. | 07-17-2014 |
20140022873 | HAIRSPRING FOR A TIME PIECE AND HAIRSPRING DESIGN FOR CONCENTRICITY - A method of increasing concentricity in use of a spiral hairspring mechanical timepiece; the hairspring having an inner terminal end portion for engagement with a collet, an outer terminal end portion for engagement with a stud, a first limb portion extending from the inner terminal end portion towards the outer terminal end portion, and a stiffening portion positioned at the outer turn of the hairspring and having a cross-sectional second moment of area different to that of the first limb portion such that bending stiffness of the stiffening portion has a greater bending stiffness than the single limb portion. The method includes modifying cross-sectional second moments of an area of the first limb portion and the stiffening portion by minimizing a cost function throughout the amplitude of the rotation of hairspring in use, the cost function being correlated to the net concentricity of the hairspring. | 01-23-2014 |