Abstract: A balance spring comprising a flat spiral coil and a non-elastic inner attachment part formed by laser beam cutting. The spring has an outer attachment plate in the plane of the coil formed with a channel which receives and protects the outer winding of the coil. The outer attachment plate has a curved attachment edge which allows the location of the oscillator dead point to be varied without affecting spring frequency.

Abstract: A balance wheel having a thermally adjustable moment of inertia is described. In one aspect, the balance wheel includes radially movable compensation portions formed of shape memory material exhibiting a two-way memory effect. The radius of gyration of the balance wheel is therefore adjustable with temperature to compensate for thermoelastic effects in a balance spring attached to the balance wheel. In another aspect, a thermally stable balance wheel includes dynamically adjusting appendages whose expansion or contraction with temperature relative to the balance wheel cause change in its moment of inertia. The invention can compensate for both ‘normal’ and ‘abnormal’ thermoelastic spring behavior.

Abstract: The application discloses a method of making a balance spring (100) from continuous fibers or ceramic by winding them around a cylindrical former (90), interspaced with a releasing agent (110). Also disclosed is a method of making a balance spring, preferably of a ceramic material (60), by applying it to a rotating former (70) mandrel or plate and subsequently heat treating. Balance wheels (30) having a moment of inertia which decreases with a rise in temperature due to a special arrangement of components (8, 9, 10) having different coefficients of thermal expansion are also disclosed. A mechanical oscillator system comprising a non-magnetic ceramic or continuous fiber balance spring (50) and a non-magnetic balance wheel (30) formed of a material having a coefficient of thermal expansion of less than 6×10?6K?1 and having a plurality of non-magnetic poising or timing appendages (5) is also disclosed.

Abstract: A balance wheel having a thermally adjustable moment of inertia is described. In one aspect, the balance wheel includes radially movable compensation portions formed of shape memory material exhibiting a two-way memory effect. The radius of gyration of the balance wheel is therefore adjustable with temperature to compensate for thermoelastic effects in a balance spring attached to the balance wheel. In another aspect, a thermally stable balance wheel includes dynamically adjusting appendages whose expansion or contraction with temperature relative to the balance wheel cause change in its moment of inertia. The invention can compensate for both ‘normal’ and ‘abnormal’ thermoelastic spring behaviour.

Abstract: A mechanical oscillator system comprising a balance wheel and a spiral or helicoidal balance spring for use in horological mechanisms or other precision instruments. The balance spring is made of a non-magnetic composite, polymer, carbon or ceramic material, preferably a composite material of carbon fibres in a polymer, carbon or ceramic matrix, and the balance wheel is made from a non-magnetic ceramic. The values of the thermal expansion coefficients for the balance spring and balance wheel are similar, very small and stable over a wide temperature range. The expansion coefficients in the axial sense of the spring and of the balance wheel are of opposite sign and they compensate one another. The density of these materials is smaller than that of the currently used metals. Through this combination of materials it is possible to obtain significant advantages and a higher level of accuracy and stability compared with metal oscillator systems.

Abstract: A balance spring comprising a flat spiral coil and a non-elastic inner attachment part formed by laser beam cutting. The spring has an outer attachment plate in the plane of the coil formed with a channel which receives and protects the outer winding of the coil. The outer attachment plate has a curved attachment edge which allows the location of the oscillator dead point to be varied without affecting spring frequency.

Abstract: The application discloses a method of making a balance spring (100) from continuous fibres or ceramic by winding them around a cylindrical former (90), interspaced with a releasing agent (110). Also disclosed is a method of making a balance spring, preferably of a ceramic material (60), by applying it to a rotating former (70) mandrel or plate and subsequently heat treating. Balance wheels (30) having a moment of inertia which decreases with a rise in temperature due to a special arrangement of components (8, 9, 10) having different coefficients of thermal expansion are also disclosed. A mechanical oscillator system comprising a non-magnetic ceramic or continuous fibre balance spring (50) and a non-magnetic balance wheel (30) formed of a material having a coefficient of thermal expansion of less than 6×10?6K?1 and having a plurality of non-magnetic poising or timing appendages (5) is also disclosed.

Abstract: A mechanical oscillator system comprising a balance wheel and a spiral or helicoidal balance spring for use in horological mechanisms or other precision instruments. The balance spring is made of a non-magnetic composite, polymer, carbon or ceramic material, preferably a composite material of carbon fibres in a polymer, carbon or ceramic matrix, and the balance wheel is made from a non-magnetic ceramic. The values of the thermal expansion coefficients for the balance spring and balance wheel are similar, very small and stable over a wide temperature range. The expansion coefficients in the axial sense of the spring and of the balance wheel are of opposite sign and they compensate one another. The density of these materials is smaller than that of the currently used metals. Through this combination of materials it is possible to obtain significant advantages and a higher level of accuracy and stability compared with metal oscillator systems.