Nikola Tesla - Free-Energy Devices

ANTI-SPARKING BRUSHES AND COMMUTATORS. 435249 and 250 are views of details of Fig. 248.Fig. 251 is a longitudinalcentral section of another modification, and Fig. 252 is asectional view of the same. A is the end of the armature-shaftof a dynamo-electric machine or motor. A' is a sleeve of insulatingmaterial around the shaft, secured in place by a screw a'.FIG. 248 FIG. 249. FIG. 250.The commutator properis in the form of a disc which is madeup of four segments n D' G G', similar to those shown in Fig. 248.Two of these segments, as D D', are of metal and are in electricalconnection with the ends of the coils on the armature. Theother two segments are of insulating material. The segments areheld in place by a band, B, of insulating material. The disc isheld in place by friction or by screws, y' g' , Fig. 248, whichsecure the disc firmly to the sleeve A'.The collector is made in the same form as the commutator. Itiscomposed of the two metallic segments E E' and the two insulatingsegments r F', bound together by a band, c. The metallicsegments E E' are of the same or practically the same width orextent as the insulating segments or spaces of the commutator.The collector is secured to a sleeve, B', by screws g g,and the sleeveis arranged to turn freely on the shaft A. The end of the sleeveB' is closed by a plate, /, upon which presses a pivot-pointedscrew, /i, adjustable in a spring, H, which acts to maintain thecollector in close contact with the commutator and to compensatefor the play of the shaft. The collector is so fixed that it cannotturn with the shaft. For example, the diagram shows a slottedplate, K, which isdesigned to be attached to a stationary support,and an arm extending from the collector and carrying a clampingscrew, L, by which the collector may be adjusted and set to thedesired position.Mr. Tesla prefers the form shown in Figs. 246 and 247 to fit