Patent GB-190413360-A (GB)
Title: Improvements in Electrical Measuring Apparatus.
Filed: 1904-06-13
Granted: 1905-06-01
Abstract: 13,360. British Thomson-Houston Co., [General Electric Co.]. June 13. Current, energy, and quantity meters. -Retates to improvements in the construction of commutator and other motor meters, and in the coils, pivots, and other details of electric meters generally. Fig. 1 shows s a front view and Fig. 2 a side sectional view of a watt - hour meter. The hollow, spherical, coreless armature is formed by winding the coils on a ball of fusible material, afterwards melted out, and is supported on the shaft by means of two small washers 11 bearing against shoulders on a split tube 10, attached to the shaft by clamps 13. A thin steel rod, fixed in a plug at the upper end of the hollow shaft, carries the commutator 8 and worm 16, and fits in a bore in the upper bearing-plug 23. The segments of the commutator, consisting of pieces of round wire coated with japan or other insulating-material, are placed upon insulating-material covering a winding of silk thread, and are held by a binding of silk thread at each end. After being baked, the commutator is turned down and some of the japan between the segments is scraped out to leave airspaces. The field coils 38, of these and of other meters, are made from ribbon conductor to surround the armature with as little clearance as possible. Each is made in two portions to fit one inside the other ; they are clamped between sheet-metal stampings 40 by means of fingers, bent up from one of the stampings, passing through holes in the other, and bent over. The stampings are fixed to the frame by screws 44. The auxiliary field coil 48 is mounted on an arm 47, pivoted to the frame and provided with a clamping-screw 46. The commutator brushes are carried by pivoted members 31, having screw-threaded arms 36 with adjustable weights or lock-nuts 37 by means of which the pressure is regulated. The registering- train is driven by means of fingers forming a flexible connection between the shafts of the wormwheel and the counting-mechanism. The brake magnets 49 are arranged in two pairs, each pair being rigidly held in a clamp 50 with unlike poles facing each other, the gap between the two magnets being considerably longer than those between the poles of each magnet. Each pair of magnets is adjustable towards and away from the shaft. The shaft may be lifted off its pivot for transport and clamped in its raised position. The plug 52, Fig. 11, having a spring-supported jewel at its upper end, screws into a sleeve 56 and holds it down against the spring 57 ; when the plug is turned, the sleeve lifts the shaft and forces a guard 15 against the lower arm of an E-shaped piece which is clamped on the upper bearing-plug. The outer tube 54 of the lower pivot screws into the frame 3 for vertical adjustment and is locked by the nut 55. This arrangement may also be applied generally. The terminals of the meter are arranged on a board 58, and behind this is a resistance 59 in the armature circuit. The back part of the casing is a casting with lugs and pillars as shown, and the sheet-metal cover is secured by the bolts 62 and wing nuts 63.