The balance-spring is formed by a first assembly, comprising the coils (3) and the outer curve (2), made in a first material such as Elinvar having an elastic torque that is insensitive or almost insensitive to elongation, temperature and magnetic field variations, and by a second assembly secured to the first assembly, comprising in particular the inner curve (4) made of a second material essentially selected for its mechanical properties and for the shapeability of said inner curve (4) along t...

A regulating device including a balance (1) and a plane hairspring (2) for a time piece movement, the plane hairspring (2) including a stiffened portion (8) in its outer turn (7) that is arranged to cause the deformations of the turns to be substantially concentric. The spacing (d) between a terminal portion of the outer turn (7) and the last-but-one turn (9) of the hairspring (2) is large enough for said last-but-one turn (9) to remain free radially during expansions of the hairspring (2) up to...

The collet is formed by a metal band (10) whose inner contour (11) delimits the recesses (11a, 11b, 11c) for driving the collet onto a balance staff (2) and whose outer contour (12) includes a function point (4) between the collet and the balance spring (9) located at the end of an arm (14) at a distance R from the centre 0 of the staff (2) greater than that of any other point (6, 8, 13, 15, 17) of the outer contour (12). It is characterised in that the inner contour (11) includes a discrete num...

The balance-spring (1) includes a plurality of coils (3) of which the end (6, 8) of the outer curve (2) is rigidified by deformation in order to define accurately the setting point (7) of said balance-spring, said deformation being able to be achieved by bending the end (6) of the outer curve (2) through 90.degree. in a plane perpendicular to the height of the balance-spring (1) or by folding down through 180.degree. a portion of the end (8) of the outer curve (2) against the inner or outer face...

An oscillating system for a mechanical timepiece includes an annular balance wheel arranged in a fixed manner coaxially in relation to a rotatably mounted balance staff. A helical spring encloses the balance staff and has its inner end fastened on the balance staff and its outer end fastened on a fastening device. The fastening device has a helical-spring connector with an inner clamping jaw and an outer clamping jaw, the inner clamping jaw being radially inside of the outer clamping jaw in rela...

A speed control mechanism has a balance with hairspring mounted to undergo oscillation movement and a regulator structure for adjusting a position of the balance with hairspring. The regulator structure is formed of a nonmagnetic material to prevent reduction of an oscillation angle of the balance with hairspring during oscillation movement thereof.

A precision regulating device for the regulator pointer of a timepiece includes a balance cock and an index regulator mounted on the balance cock such that the index regulator is pivotable about a regulator axis. A hairspring key arranged on the index regulator at a radial distance from the regulator axis allows changing the active length of a hairspring of the oscillating system of the timepiece in response to pivoting of the index regulator. The index regulator also includes a radially directe...

The anti-trip device is for a detent escapement mounted on a wristwatch. It includes a finger fixed to the arm of the balance, two columns between which the finger can pass, said columns being secured to the balance bridge, and a locking arm fixed to the outer coil of the balance spring, said locking arm being able to be inserted between said columns and said finger to prevent the balance from rotating beyond an angle exceeding its normal operating angle. The locking arm is a clamp hooked onto t...

A method for manufacturing a balance-spring for a clockwork movement wherein a spring is formed by winding, from a wire or metal strip, said spring including an inner end intended to be fixed to a balance and a outer end zone intended to be fixed to the balance-spring stud and wherein the whole spring is subjected to a first heat treatment subsequent to the winding step of said wire. The method of the invention is characterized in that it further includes an additional step consisting in subject...

According to a rate adjusting method, the movement of a mechanical timepiece is first assembled. The assembled movement is then disposed in a vertical position, and the rate is measured with respect to a plurality of vertical positions. On the basis of the result of this rate measurement, the magnitude and direction of the positional difference vector are calculated. On the basis of the result of this calculaton, the amount of weight to be added to or subtracted from the annular balance of the m...