The Talking Machine Encyclopaedia PDF Download

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 edition. Excerpt: ... power escapes here the wear and tear is very great. Lubricant for this gear should consist of heavy grade oil. (See also Gear, Intermediary Gear, Motor.) Pl-l9Y----A wheel which has a fiat surface (sometimes a V groove) for its periphery. It is used in combination with a belt of leather, or other substance, for the transmission of power. Pulleys occur in the talking machine on the mandrel shafting of a phonograph and on the motor. A small leather belt is usually used to connect the two. (See Belt.) R3-tcents'9t and PaW---A mechanical combination by means of which the strength of a wound-up spring is-preserved. It will be obvious that when a spring is being wound, some device must be used to prevent it from flying back; the ratchet wheel and rocking pawl are usually put in for this purpose, although there are alternative devices in the ratchet wheel and spring bind. The device consists of an wheel, toothed around its periphery at regular intervals, the teeth being of such shape as to receive the end of the pawl, and to raise it when the wheel is advanced. The pawl has a conveniently shaped end, and is depressed on to the ratchet by means of a spring, which resists the upward thrust that revolving the ratchet in winding gives it at the passage of each tooth; it is thus pressed into each tooth as it comes round, hence the wheel cannot run back. (See Pawl, Spring Bind.) R0cents0rd---At the present time there are three distinct kinds of sound records on the market. (1) Cylinder (moulded); (2) needle or V cut disc; (3) threeway cut or phono disc. As the third is but an adaptation of the system and cut of a cylindrical record to a disc, they may be dealt with together in general terms, reserving W.ith E_dis61's.o1: i