Twentieth century hand-book for steam engineers and electricians, with questions and answers .. (1905)
Swingle, C. F. [from old catalog], Horstmann, Henry Charles, 1858- [from old catalog], Tousley, Victor Hugo, 1875- [from old catalog] · Chicago, F. J. Drake & co. · leaf 476
s, thereby ELECTRICITY FOR ENGINEERS 57 burning a small hole wherever such a particle of emery-has lodged itself. The emery will also work into thebrushes and copper bars and wear them down; it beingalmost impossible to remove all the emery. In the end-on carbon brushes, Fig. 30, the contactsurface… … FIGURE 29. leaving the tension of the brush down on the sand-paper, it is an easy matter to move the sandpaper toand fro and throughly clean off the glazed and dirtysurface from the carbon, leaving it with a concave thatwill exactly fit the commutator. The advantages of carbon brushes are…
