Displacement characteristics of one-piece parallel spring movement for balance (7th report) ― Modification of the error rate of displacement due to dimensional errors of the right half circular springs

So far, authors have clarified the effects of dimensional errors of the parallel spring move-ment with right half circular springs on the error rate of displacement. Although it is desirable for balances that the dimensional errors of springs are eliminated by machining, such a work itself, however, takes engineers much time to correct the dimensional errors. So, the authors propose here a notched springs by which the error rate of displacement can be modified without eliminating the dimensional errors. Following is concluded through theoretical, experimental and FEM analyses. (1) In case of the movement with two circular springs, a notch at around±16deg measured from the position with theminimum thickness is most effective formodification, while the one at the minimum thickness contributes to no modification. (2) In case of that with four circular springs, a notch at around ±3deg measured to the outsides, respectively, from the position with the minimum thickness is most effective for modification, while the one near reinforcing plate shows a few effect.