Abstract: An instantaneous date control device for a timepiece, in particular for a mechanical wristwatch, including: a date disc, a gear train forming a kinematic linkage between the control device and a horological movement of said timepiece, a first mobile including a first toothed wheel driven at a speed of one turn per day and a cam mounted freely rotatably, over a limited angular range and/or in a single direction of rotation, as well as temporarily coupled in rotation to said first toothed wheel, a second mobile including a second toothed wheel driven at a speed of one turn per day, an unlocking and driving yoke carrying a feeler bearing on said cam and a driving finger which can mesh with teeth located on the date disc, an unlocking and driving spring, and a retaining means allowing to secure the angular position of the date disc between two instantaneous jumps.

Abstract: A method for fixing pieces by freezing which consists in fixing the pieces o be machined on an auxiliary support having good thermal conductivity, for example made of aluminium, by freezing onto an freeze vice on the copper plate of which there has previously been deposited a film of antifreeze liquid. The auxiliary support is fixed to the freeze vice by vacuum, by magnetism, or by any mechanical clamping. This method makes it possible to eliminate the operation and the time for thawing which, up until now, was required for removing the pieces to be machined from the freeze vice. The auxiliary support may be used as a transfer pallet on which the pieces are held by freezing.