US 12,306,586 B2
Device for fastening a back on a middle for a timepiece
Joël Allimann, Vallon (CH); and Benjamin Chartrel, St-Blaise (CH)
Assigned to The Swatch Group Research and Development Ltd, Marin (CH)
Filed by The Swatch Group Research and Development Ltd, Marin (CH)
Filed on Sep. 26, 2022, as Appl. No. 17/952,689.
Claims priority of application No. 21212693 (EP), filed on Dec. 7, 2021.
Prior Publication US 2023/0176525 A1, Jun. 8, 2023
Int. Cl. G04B 37/00 (2006.01)
CPC G04B 37/0008 (2013.01) 17 Claims
OG exemplary drawing
 
1. A fastening device for fastening (100) a back on a middle of a watch, the back (2) having a shoulder (20) forming a cover (21) arranged to cover totally or partially the middle (1) and a body (22) arranged to rest in the middle (1), said device comprising a ring (3) mounted between the back (2) and the middle (1) and integral with the middle, and at least one pin (4) integral with the back and arranged to cooperate with the ring and the middle,
wherein said ring (3) comprises, at least one recess (5) arranged to cooperate with the pin (4), said pin (4) being capable of sliding in the recess (5) between a first position, the first position being an insertion position wherein the back (2) is free, and a second position, as the second position being a locking position wherein the back (2) is locked and angularly positioned in relation to the middle (1), and
wherein said recess (5) comprises at least one bump (55) to form a hard spot and increase torque during passage of the pin (4) at the bump (55).