. The practical telephone handbook and guide to the telephonic exchange . Fig. 166 a.—Scale f. Fig. 167.—Scale f the lifting of the drop shutter into its normal position. Thereare a large number of varieties of these instruments, the SWITCH-BOARD APPARATUS I5i simplest being those having a kind of cam projection on thefront of the drop shutter, which, when the plug is inserted inanswer to a call, is lifted upward by an enlarged collar on theplug, so as to carry the shutter to its normal position, as shownin Fig. 167. Another form of this kind of apparatus is shown in , in which the bott
. The practical telephone handbook and guide to the telephonic exchange . Fig. 166 a.—Scale f. Fig. 167.—Scale f the lifting of the drop shutter into its normal position. Thereare a large number of varieties of these instruments, the SWITCH-BOARD APPARATUS I5i simplest being those having a kind of cam projection on thefront of the drop shutter, which, when the plug is inserted inanswer to a call, is lifted upward by an enlarged collar on theplug, so as to carry the shutter to its normal position, as shownin Fig. 167. Another form of this kind of apparatus is shown in , in which the bottom long-line spring of the spring-jack ahas a kind of stirrup loop formed on its end. This is bent up-ward so as to intervene between the end of the ironclad magnetand the drop shutter d. The shutter has attached a pro-jecting-piece, which passes to the back through a hole in theframe-piece f, so that when the shutter falls the projecting
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Keywords: ., bookcentury1900, bookdecade1900, booksubjecttelephone, bookyear19
