Vibrating system with continuously variable frequency and amplitude, in particular for shaking tables, dynamic materials-testing machines and the like

摘要

946,589. Testing machines. W. & T. AVERY Ltd. Jan. 23, 1961 [Jan.22, 1960], No. 2538/61. Heading G1S. A vibrating system for shaking tables or dynamic testing machines has a variable frequency and amplitude. Table 3 is attached to rod 2 secured to a table 8, 9 through a springy membrane 1. The table is vibrated by activator 6 and frequency is varied by introducing pressure medium into cavity 11 and forcing vibrating membrane 1 against sides 8b thus reducing its effective area. Other embodiments in which a spring element is braced against a fixed shape are shown. The embodiment shown in Fig. 1 is a shaking table and that in Fig. 5 a dynamic testing machine.