Timepiece sub-assembly including a balance spring stud arranged to be fastened to a balance cock, and a balance spring comprising an outer coil and an end plate of larger section than that of the outer coil, this stud including a housing arranged, in a first free state of the sub-assembly, to loosely contain the end plate with tangential mobility with respect to the outer coil, and, in a second immobilised state of the sub-assembly, to immobilise the end plate to which the housing is joined by a layer of adhesive covering a change-of-section shoulder and which forms a mechanical seal for the balance spring in a longitudinal direction of the housing, and the end plate includes an eye communicating with the layer in the second immobilised state.

Timepiece sub-assembly including a balance spring stud arranged to be fastened to a balance cock, and a balance spring comprising an outer coil and an end plate of larger section than that of the outer coil, this stud including a housing arranged, in a first free state of the sub-assembly, to loosely contain the end plate with tangential mobility with respect to the outer coil, and, in a second immobilised state of the sub-assembly, to immobilise the end plate to which the housing is joined by a layer of adhesive covering a change-of-section shoulder and which forms a mechanical seal for the balance spring in a longitudinal direction of the housing, and the end plate includes an eye communicating with the layer in the second immobilised state.

An elastic retaining member for attaching a timepiece component to a support element, includes an opening into which the support element is likely to be inserted, the retaining member includes rigid arms and elastic arms defined between connecting zones helping to ensure elastic clamping of the support element in the opening the rigid arms being provided with the only contact zones of the retaining member with the support element and in that, the rigid or elastic arms each extend longitudinally between connecting zones, the rigid arms and the elastic arms being arranged in the retaining member successively and alternately and each rigid arm has a volume of material greater than the volume of material constituting each elastic arm.

An elastic retaining member for attaching a timepiece component to a support element, includes an opening into which the support element is likely to be inserted, the retaining member includes rigid arms and elastic arms defined between connecting zones helping to ensure elastic clamping of the support element in the opening the rigid arms being provided with the only contact zones of the retaining member with the support element and in that, the rigid or elastic arms each extend longitudinally between connecting zones, the rigid arms and the elastic arms being arranged in the retaining member successively and alternately and each rigid arm has a volume of material greater than the volume of material constituting each elastic arm.

A balance spring, in particular for a horological regulating member, the balance spring (100) including a flexible strip (2) wound about itself in several turns, the strip (2) having a predefined stiffness, the balance spring (100) having a stiffener for adjusting its stiffness, the balance spring (1) also including an actuator (10) for actuating the adjustment means, depending on the ambient temperature. Also, a horological regulating member including such a balance spring.

A method produces an assembly of an elastic holding member-timepiece component assembly with a support element. The elastic holding member is made of an electrically insulating material and the support element is made of an electrically conductive material. The method includes mounting the assembly with the support element aiming to define at least one zone for receiving at least one element for blocking a movement of the holding member relative to the support element, and producing by galvanic metal growth the at least one blocking element on at least one of the reception zones.

A balance-spring stud holder includes a clamping part defining three contact zones intended to press against a lateral wall of a projecting part of the balance bridge, a first contact zone being connected to a second contact zone by a first part and to the third contact zone by a second part of the clamping part. The first part has a first stiffness at a second median point of the second contact zone, relative to a first median point of the first contact zone, which is greater than three times a second stiffness that the second part has at a third median point of the third contact zone relative to the first median point of the first contact zone. The first stiffness can be seven times greater than the second stiffness.

A balance-spring stud holder includes a clamping part defining three contact zones intended to press against a lateral wall of a projecting part of the balance bridge, a first contact zone being connected to a second contact zone by a first part and to the third contact zone by a second part of the clamping part. The first part has a first stiffness at a second median point of the second contact zone, relative to a first median point of the first contact zone, which is greater than three times a second stiffness that the second part has at a third median point of the third contact zone relative to the first median point of the first contact zone. The first stiffness can be seven times greater than the second stiffness.

An attachment monolithic part for fastening a timepiece component on a support element, including an opening into which the support element could be inserted, the attachment part including elastic arms contributing to ensuring an elastic clamping of the support element in the opening, each arm consisting of a contact portion provided with a through hole and with a connecting portion, the contact portion including a receiving region provided with a bearing area intended to come into contact with the support element and the connecting portion ensuring an elastic connection with another one of the arms of the part.

An attachment monolithic part for fastening a timepiece component on a support element, including an opening into which the support element could be inserted, the attachment part including elastic arms contributing to ensuring an elastic clamping of the support element in the opening, each arm consisting of a contact portion provided with a through hole and with a connecting portion, the contact portion including a receiving region provided with a bearing area intended to come into contact with the support element and the connecting portion ensuring an elastic connection with another one of the arms of the part.