Improved Means for Compensating Clock Pendulums having an Alternating Rotary Movement.

摘要

17,212. Grivolas, C. Feb. 19, [Convention date]. Pendulums. - Torsion pendulums are compensated for changes in temperature by means of one or more tubes containing mercury, arranged in the pendulum box, so that the distribution of the oscillating mass about the axis is varied automatically by the displacement of mercury. Fig. 3 shows one form in elevation; Figs. 5 and 9 show modifications in plan and elevation respectively. Each compensator, which is like a thermometer tube, has a large bulb A at one end, which may contain a very expansible liquid in contact with a thread of mercury in the capillary tube B. The liquid in A (which, may, however, be dispensed with), by its expansion, drives the mercury into a smaller bulb D, which terminates the tube at its bentup end C, and is situated near the centre of the pendulum-box. When a number of tubes are used, they are symmetrically arranged, and may contain liquids having different coefficients of expansion, Fig. 13. The compensators may be used in conjunction with radially movable regulating-weights H, H1. If the expansion of the suspension-ribbon is irregular, the capillarytube B may be suitably bent, as shown, for example, in Figs. 5 and 9, so that its compensating action is correspondingly modified.