Integral assembly of a hairspring and a collet

An integrated hairspring-collet assembly comprising an element configured to continuously surround a balance staff and comprising:

• a first receiving part configured to bear against the balance staff,
• a second receiving part configured to bear against the balance staff,
• a first connecting part arranged to connect the first and second receiving parts,
• a second connecting part arranged to connect the first and second receiving parts, and
• wherein each of the first and second connecting parts is more deformable than each the first and second receiving part,
• wherein a radial dimension of each the first and second connecting parts varies along at least a portion of a peripheral length of the connecting part.

An integrated hairspring-collet assembly made of a material that has no plastic deformation domain, in which:

• the contour of the collet is a closed contour,
• the central opening of the collet which is intended to receive a balance staff is non-circular,
• the contour of the central opening of the collet comprises at least first and second bearing surfaces for a balance staff;
• wherein
• the collet is formed of first and second balance staff receiving parts located facing one another, wherein the first balance staff receiving part comprises at least the first bearing surface for the balance staff as well as an attachment point for the hairspring, and the second balance staff receiving part comprises at least the second bearing surface for the balance staff, and
• the first and second balance staff receiving parts are connected to one another by two connecting parts which have a lower rigidity than the receiving parts so that they deform elastically as a balance staff is driven in, and a transverse cross-sectional area of at least one portion of each of the connecting part along a peripheral length thereof is smaller than a transverse cross-section area of the respective connecting part at a junction with at least one of the receiving parts at a base of at least one of the first and second bearing surfaces.