| 摘要 |
601,243. Piezo-electric crystals. GENERAL ELECTRIC CO., Ltd., WOOSTER, N. A., WOOSTER, W. A., RYCROFT, J. L., THOMAS, L. A., and FIELDING, E. A. Jan. 23, 1946, No. 2227. Addition to 580,965. Drawings to Specification. [Class 40 (v)] A quartz plate is made from quartz which manifests electrical twinning by heating the plate to a temperature which is not appreciably greater than its alpha-# inversion temperature, and may be much less, and then cooling the plate while it is strained by subjection to mechanical stress, and possibly strained also by a temperature gradient imposed on it, so as to reverse the positive directions of the electrical axes of at least a portion of the plate, thus reducing the proportion of the plate that is electrically twinned. The operation is carried out as described with reference to Fig. 15 of the parent Specification, but at a lower temperature. Graphs are included which show suitable ranges of values of the applied mechanical torque and temperature, |
