GB291448A - - Google Patents

Abstract

291,448. Metropolitan-Vickers Electrical Co., Ltd., (Assignees of Vaughan, V. G.). June. 4, 1927, [Convention date]. Indicators and alarms, applications of; protection or safety devices, auxiliary.-A temperature indicating system for a dynamo-electric machine comprises a thermallyresponsive switch 41 disposed in thermal relation, with the armature. 18 and the switch is adapted to close the circuit of an electro-responsive indicating device such as a bell 36 energized from the armature winding, when a. predetermined temperature is reached. The switch is secured to the rotor spider 17 in proximity to the end windings 19, 21 which are usually at the maximum temperature and the bell is mounted on an arm 27 projecting from the rotor spider 17 and bolted to the spokes 22 of the commutator support. The bell is energized from the commutator by connecting the leads 38, 39 to a pair of segments 33 between which exists to a suitable difference of potential. The conductors 38, 39 may be connected to slip rings whereby an external relay may be energized to effect de-energization of the machine. The thermal switch mav be of the type described in Specification 178,103, [Class 38 (v), Electric switches &c.].