Patent GB-1183110-A (GB)
Title: Bracelet Clasp
IPC: A44C5/18
Filed: 1967-12-29
Abstract: 1,183,110. Releasable fastenings. OMEGA LOUIS BRANDT & FRERE S.A. 29 Dec., 1967 [6 Jan., 1967], No. 59163/67. Heading E2A. [Also in Division A3] A clasp for a bracelet comprises three elements 1, 2, 3 hinged together and adapted for folding so as to become superimposed in closed position, one of the outer elements 3 having means for engaging the other outer element 1 to hold the elements superimposed, the outer elements having a substantially perpendicular U-shaped cross section and each carrying adjustable securing means for one of the extremities of the bracelet said means consisting of a part 8 or 9 which can be secured to the bracelet and a fastening mechanism cooperating with the lateral walls of the outer element I or 3 in such a way that said means is retained by said lateral walls in fastening position and is movable relative to said walls in releasing position. In the construction shown the means for holding the elements superimposed consists of bosses 30 and 31 provided by the lateral walls of the element 3 which engage the walls 1a and 1b of the element 1. The parts 8, 9 of the securing means which engage the bracelet extremities each consist of a plate folded to U-shape to provide two wings between which the extremity of the bracelet is received, the wings then being rivetted to the extremity; the fastening mechanism consists of a plate 15 welded onto one wing and having a thickness equal to the space between the wings, the plate 15 having a cut out 15a which with the base wall 9b of the U-shaped parts 8 or 9 provides a track for a slider 16 and a recess for a cam 17 by means of which the slider is moved. Movement of the slider is limited by a projection 15c of the plate 15 which engages in a recess 16a of the slider. The cam has two flat sides and an arcuate side and when one flat side is engaged with the slider it is in the fastening position and when the other flat side is positioned adjacent the slider, the slider can be moved to releasing position; the slider is provided with teeth which engage teeth in one of the lateral walls of the corresponding outer element and the plate 15 also has corresponding teeth which engage teeth in the opposite lateral wall of the corresponding outer element; the flanks of all the teeth are at 45 to the direction of movement of the slider and the pitch of the teeth of the slider and of the plate 15 is twice the pitch of the teeth of the lateral side walls. When the cam is in the releasing position the slider 16 can be moved by pulling on the bracelet, the teeth moving the slider to the releasing position. The cam is rotated by a tool received in a slot 18, the wings of the U-shaped element being suitably apertured to allow access to the slot. To avoid complete disconnection of the extremities of the bracelet from the clasp the part 8 is retained in its element 1 by a telescopic device of known type comprising a cylinder in which slides a pin 27 biassed by a spring housed in the cylinder and which device is put in position after the introduction of part 8 in element 1. The part 9 is retained in position by two projections 28, 29 made by shearing and folding part of the walls of the element 3; the bracelet is distorted to enable it to pass between the projections. In a modification each securing part 8, 9 has teeth on one side only to engage teeth of one wall of the corresponding outer element the other wall of the outer element and the corresponding portion of the part 8 or 9 being smooth.