US 5,303,213 AGranted

Unidirectional correction arrangement for a time displaying device

AssigneeETA SA Fabriques d'Ebauches

InventorLaurent Kaelin

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Abstract

This unidirectional correction arrangement (1) for a display device exhibiting a circular element (2) provided with teeth (3) includes a cylindrical element (4) around which is wrapped a helical spring (5), one of the ends of which serves as a finger (6) adapted to come into contact with a tooth (3). When the cylindrical element (4) is driven in rotation in a sense (A) for which the force (F1) exerted on the finger by the tooth is directed in a sense tending to wrap the spring around the cylindrical element and to tighten it therearound, the circular element (2) rotates. Such circular element (2) will not be driven when the cylindrical element (4) is driven so as to rotate in a sense (B) for which the force (F2) exerted on the finger by the tooth is directed in a sense tending to open the helical spring.

Claims7

Dependent claims

A unidirectional correction arrangement for at least one time displaying device in a timepiece, said display device having a circular element provided with teeth, comprising:

a cylindrical element, a lightly tightened helical spring wrapped around the cylindrical element, the spring having two ends, one of which ends is radially raised so as to serve as a finger adapted to come into contact with a tooth of the circular element and to cause the circular element to rotate only when said cylindrical element is driven in a first sense (A) of rotation for which a force exerted on the finger by the tooth is directed in a sense tending to wrap the helical spring around the cylindrical element and to tighten it thereabout, said circular element remaining stationary when the cylindrical element is driven in a second sense (B) of rotation for which the force exerted on the finger by the tooth is directed in a sense tending to open the helical spring and to free it from said cylindrical element.

Dependencies are inferred from the claim text.