The Practical Telephone Handbook; And Guide to the Telephonic Exchange

The Practical Telephone Handbook; And Guide to the Telephonic Exchange

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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1895 edition. Excerpt: ...pole (where a coil of it is buried), and is stapled round the arms between each pair of insulators. This is intended to intercept any leakage which may occur over the insulators, and prevent its leaking into the adjoining w ires carrying it off to earth instead. The earth wire is sometimes connected to the bolts of the insulators but this is a mistake, as unless the wire makes good earth (which is very seldom the case) it helps the leakage from one wire to another, and causes excessive leakage to earth in wet weather. Stays.--When the poles arc exposed to heavy strains by the wires going off at an angle, stays or guys are used to prevent thej pole going over in the direction of the strain. They are usually made up of seven No. 8 galvanised iron wires twisted together. One end of this is taken twice round the top part of the pole, the best position being midway between the top and bottom arms, so that it may act at the resultant point of the total pull of the wires on the pole. A hole is dug as far from the foot of the pole as is convenient, and in this hole a block of creosoted timber is placed, through which a long bolt, called a stay-rod, provided with a large washer-plaie, is passed. The whole should be undercut, as shown in Fig. 190, so that the pull may be against solid earth. The top of the stay-rod is provided with a swivel, to which one end of the stay is attached. The swivel is so arranged that by turning a nut the stay can be tightened up. Sometimes two or three stays are required where the strain is excessive. Where the wires go off at nearly a right angle, it is better to fix two stays or two double stays, one being fixed in a. line with one direction of the wires, and the second in a line with the other direction. Struts.--In...show more

Product details

  • Paperback | 80 pages
  • 189 x 246 x 4mm | 159g
  • Rarebooksclub.com
  • Miami Fl, United States
  • English
  • black & white illustrations
  • 1236528026
  • 9781236528025