Patent ID: 8297833

Claim:
An assembly for securing the peripheral end of the balance-spring of a sprung balance device for a timepiece, including: a balance-spring stud holder, secured to a balance-cock and positioned to enable the outer end of the balance-spring to be fixed in a channel in the stud holder, and devised to house a stud against which the balance-spring can be locked; a screw for locking the balance-spring stud, which comprises a threaded body for assembly inside an inner thread of the stud holder that opens onto the channel and which pushes the stud towards a back face of the channel and allows the balance-spring to be secured by insertion between the stud and said back face of the channel, wherein: the locking screw has a tip in the extension of the threaded body, at the opposite end to the screw head; and the stud has a housing into which the tip can be inserted.