Improved Electric Temperature-signalling Device

18,827. Klopfenstein, C., and Klopfenstein, G. Aug. 31. Thermometers.-Relates to electric apparatus for energizing an alarm or other signal when the temperature rises to a predt termined amount. In the arrangement shown in Fig. 4, a fragile tube 2, containing mercury,which is open at its upper end, and is provided with a bulb 2 at it lower end, is secured above a temperature scale 3 on a base 1. A wire 9 adjustable in the open end of the tube 2 by means of a screw 9 mounted in a bracket 6 is connected through a battery B' and electric bell A' to a binding-post 8. A wire 8 connects the binding-post 8 to the mercury in the bulb 2. When the mercury rises to the wire 9, the bell is sounded. A second bell A and battery B are arranged in a circuit between a rigid contact a secured at one side of the bulb 2 and a spring contact b which is held normally away from the contact a by the bulb 2. The wire 9 is set so that the first bell sounds before the other device acts. If the temperature is not re,tified, the mercury then breaks the bulb by its expansion and allows the contact b to engage the contact a and energizes the other circuit. The two bells may be arranged in different places. In a modification, only the bell A and battery B are used, the parts 8, 9 being connected to the contacts a, b respectively.