. American telephone practice . rgized. The type of relay now used for line and supervisory work by theWestern Electric Company in the switch-board they manufacturefor the various Bell companies is shown in Fig. 388. This is a modification of the tilting armature type shown in Fig. MULTIPLE SWITCH-BOARD APPARATUS. 537 386, and needs little explanation. For supervisory purposes whereit is important to prevent cross talk, the outer shell, g, of this relayis made of copper about 3-32 inch thick. This type of relay is alsoused as a line relay for lighting the line lamp, but in this case thecopper
. American telephone practice . rgized. The type of relay now used for line and supervisory work by theWestern Electric Company in the switch-board they manufacturefor the various Bell companies is shown in Fig. 388. This is a modification of the tilting armature type shown in Fig. MULTIPLE SWITCH-BOARD APPARATUS. 537 386, and needs little explanation. For supervisory purposes whereit is important to prevent cross talk, the outer shell, g, of this relayis made of copper about 3-32 inch thick. This type of relay is alsoused as a line relay for lighting the line lamp, but in this case thecopper shell is omitted, and all of the relays on the strip are enclosedin a common dust-proof case. The type of relay now largely used by the Bell companies fortheir cut-off relay, or, in general, where several contacts have to bemade and broken, is shown in plan, elevation and section in Fig. 389. In this, m, is the mounting strip to which is secured the core, a,carrying at its rear end an angular pole-piece, d, and at its front end. d . m v^ FIG. 388.—WESTERN ELECTRIC LINE RELAY. a similar piece, d; secured to the under side of the pole-piece, d, bya spring, e, is an armature, e, projecting forwardly under the hori-zontal portion of the angular pole-piece, d. This armature is there-fore raised by the magnetic pull of the two pole-pieces when thecoil is energized. The armature thus serves to complete the mag-netic circuit between the two pole-pieces. The downward move-ment of the armature is limited by the adjustment screw, f, againstwhich it rests when not attracted. The range of movement of thearmature may be adjusted by means of this screw, as is readily on the upper face of the pole-piece, d, are two pairs of con-tact springs, i and g, i and g\ these springs carrying platinum con-tact points at their forward ends, and are so arranged that the upper 538 AMERICAN TELEPHONE PRACTICE. spring will normally make contact with the lower one. The lowerspring, i, in each ca
Size: 1581px × 1581px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., boo, bookcentury1900, bookdecade1900, bookidamericantelepho00mill
