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 the outer coil of the balance spring.

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 relation to the axis of rotation of the balance staff. The outer end of the helical spring may be clamped firmly between a clamping surface of the inner clamping jaw and a clamping surface of the outer clamping jaw.

A spiral spring for use in connection with horology instruments is disclosed which includes a spiral spring and a collet which are produced in one piece without molecular discontinuity.