Master Dynamic Limited

Pui Hang Ko

Ho Ching

Siu Kay Chu

A torque-restoring element for an oscillator for a mechanical timepiece and having an oscillator frequency, said torque restoring element comprising a spiral spring body having a number N turnings with an inner terminal end for engagement with a rotational inertial element via a collet, and an outer terminal for engagement with a stationary cock element, and having a width, a height and a total arc length; wherein the spiral spring body includes a core formed from mono-crystalline silicon wafer oriented along the crystallographic axis &#x3c;110&#x3e;; and wherein the spiral spring body includes at least one peripheral coating of a material having a thermal elastic constant different from that of the core of the spiral spring body so as to maintain the oscillator frequency an oscillator including the torque-restoring element substantially insensitive to variations of ambient temperature.

Silicon hairspring

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, the 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 the central axis at a first distance and wherein the first distance is less than the radius of the staff of the balance wheel; the engagement portions have a radius of curvature such that upon deformation of the arm portions and engagement with the outer surface of the staff the engagement portions substantially conform with the outer surface of the 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.

Growing community of inventors

Hong Kong, China

Pui Hang Ko