A device for tracking and representing the play vorga narrow in the case of movement operations, in particular in the case of base ball games

摘要

272,271. Brown, W. J., and Metropolitan Vickers Electrical Co., Ltd. March 4, 1926. No Patent granted (Sealing fee not paid). Thermal switches, cut-outs, and interrupters; alternating-current relays. - An electrically-conducting body is arranged in inductive association with a conductor so as to become heated by eddy currents induced in it when an alternating current flows through the conductor, a device responsive to change in temperature of the body being in thermal association therewith. As shown in Fig. 1 a coil 11 carries the current to be measured, particularly a radio-frequency current, and embraces the bulb 13 of a mercury thermometer. The mercury in the bulb becomes heated by induced currents, and the seals may be calibrated to read current at a particular frequency. Contacts 17, 19 may be sealed into the bulb and stem for closing an auxiliary circuit when the current reaches a predetermined value. The bulb may be lagged or vacuum jacketed. In a modification, Fig. 2, a differential gas thermometer is employed. The coil 11 is arranged around one bulb 13a which either consists wholly of metal or other conductor or is covered inside or outsido by electrodeposition or otherwise; with a conducting layer. Alternatively a conducting body may be placed within the bulb 13a. The legs of the U-tube 21 are bridged by a tube 23 with a stopcock 25 fcr equalizing the pressure in the bulbs 13a, 13b when they they are at the same temperature. In a further modification shown in Fig. 5, suitable for high-frequency currents of large magnitude, a bimetallic strip 31a is surrounded by a coil 17 or is arranged parallel to a straight conductor, and operates an indicating- pointer through threads 41, 43. A second bimetallic strip 31b may be arranged as shown to compensate for changes in atmospheric temperature. The strip 31a may carry a contact at its free end co-operating with a fixed contact, preperably with a snap action. Reference has been directed by the Comptroller to Specifications 77/02, 493/02, 17667/02, 18181/03, 132,567, [all in Class 37, Electricity, Measuring &c.], and 211,492.