This paper is concerned with some ca1cu1ations of fork which consists of a uniform rod. The direction of displacement of the fork is at right angles to the plane of the tuning fork. Natural frequencies and mode shapes arecalculated on the basis of the usual method. Experimental verification has been performed for the fundamental mode. This result is fairly in good agreement with experiment.
"SPIRAL CRYSTAL VIBRATOR" is our coined word. This new type spiral has been defined as ARCHIMEDES' spiral band with several turns, having the larger band width than its thickness. Clamping in the vicinity of its outside terminal, every part of spiral can be caused to move in normal direction of the band width. This results primarily a tortional moment acting on the cross section of every Part of spiral band. The situation is analogous to that of A CONICAL COIL SPRING. The device for maintaining vibrations is realized by using a electromagnetic transducer for pick up and drive functions. Typical frequency is only 156 Hz. It is also available in frequency range from 130 to 800 Hz. This paper presents the results as follows; A mathema tical statement of equation concerning to frequency. Temperetuteecoefficient of frequency vs. crystal cuts of plates. Vacuum sealing effect of glass tube to attain high Q value. Summarized aging data for a few months.