ROTOWIND

Cal. 535 - 539

Discover how we developed the ROTOWIND® movement and learn from the patent application that started in 1951 to the completed project in 1953. It took more than 2 years of research and development to achieve the famous ROTOWIND® automatic movement with unprecedented reliability.

CH290950

PATENT SPECIFICATION N°290950

MAI 2, 1951, 5½ p.m, Class 71e

Buren Watch Co s/A. Büren (Switzerland).

Watch with automatic winding by oscillating weight.

The subject of the present invention is a watch with automatic winding by oscillating weight, comprising a pinion actuated by the rotation of the oscillating weight and two wheels of a winding train meshing with each other.

Characterised by two rockers each carrying a reference meshing with said pinion and located in the same plane as the latter, said transmissions coming into contact, during automatic winding and according to the direction of rotation of the oscillating weight, alternately with one of the wheels of said reassembly train, and two springs each acting on one of said levers and pressing it in the direction of the respective wheel of the winding train.

CH297476

PATENT SPECIFICATION N°297476

OCTOBER 29, 1951, 6½ p.m, Class 71e

Buren Watch Co s/A. Büren (Switzerland).

Automatic watch winding mechanism.

The object of the present invention is an automatic watch winding mechanism by the movements in both directions of an oscillating mass. The making mechanism.

The object of the invention comprises four mobiles, namely a pinion mounted coaxially on the oscillating mass, a sliding pinion and two identical toothed wheels engaged with each other and whose axes are located at equal distance from that of said mass, the sliding pinion still being engaged with the pinion mounted on the oscillating mass, the latter leading alternately said sliding pinion, according to the alternations of said oscillating mass, engages with one and the other of the two gears wheels.

CH305464

STATEMENT OF INVENTION N°305464

NOVEMBER 6, 1952, 6¼ p.m, Class 71e

Buren Watch Company s/A. Büren a. d. A. (Switzerland).

Watch with automatic winding and manual winding.

The object of the present invention is a self-winding watch. and manual winding, in which the barrel ratchet is actuated by two independent gear trains, corresponding respectively to the two mechanisms (the winding.

Watches of this type generally comprise a device disengaging the members of the automatic winding mechanism when the watch is wound by hand and a device disengaging the members of the manual winding mechanism when the watch is wound automatically. When the automatic winding mechanism includes a ratchet, the first of said release devices is constituted by this ratchet.

When, on the other hand, the automatic winding mechanism comprises only the wheels, a freewheel device is inserted in the gear train of the automatic winding mechanism. Such a freewheel device, however, complicates the construction and increases the cost of manufacturing the watch.

**Rotowind** **Cal.539** *BUREN WATCH COMPANY SA*

CH314384

PATENT SPECIFICATION N°314384

OCTOBER 6, 1953, 6½ p.m, Class 71f

Buren Watch Company s/A. Büren a. d. A. (Switzerland).

Axial thrust bearing.

The object of the present invention is an axial thrust bearing for the pivot of a mobile, in particular of a mobile device such as a timepiece, measuring instrument, etc., in which a circular element serving as an axial abutment is held axially in place in a bearing body by a device comprising a circular ring.

Constructions of this type are already known, in particular bearings for the wheel set of a watch train, constructions in which said ring is split and is retained on a notch on a bezel carrying a pierced stone; that is, the ring has a tapered edge and a tapered groove is provided on the bezel. The positioning of said ring is then done by bringing its two free ends together with a view to closing it and thus introducing it into said groove.