The Run.

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—The run or, as it is sometimes called, “the slide,” should also be as light as possible; from ¼° to ½° is sufficient. It follows then, the bankings should be as close together as possible, consistent with requisite freedom for escaping. Anything more than this increases the angular connection of the balance with the escapement, which directly violates the theory under which it is constructed; also, a greater amount of work will be imposed upon the balance to meet the increased unlocking resistance, resulting in a poor motion and accurate time will be out of the question. It will be seen that those workmen who make a practice of opening the banks, “to give the escapement more freedom” simply jump from the frying pan into the fire. The bankings should be as far removed from the pallet center as possible, as the further away they are pitched the less run we require, according to angular measurement. Figure6 illustrates this fact; the tooth S has just dropped on the engaging pallet, but the fork has not yet reached the bankings. At a we have of run, while if placed at b we would only have ½° of run, but still the same freedom for escaping, and less unlocking resistance.

The bankings should be placed towards the acting end of the fork as illustrated, as in case the watch “rebanks” there would be more strain on the lever pivots if they were placed at the other end of the fork.

Diagram showing two right-angled triangles with a weight labelled 2 at the bottom of each slope. The first triangle slopes more.

Fig.7.

                                                                                                                                                                                                                                                                                                           

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