| 摘要 |
<p>1,151,784. Sets. SOC. ITALIANA TELECOMMUNICAZIONI SIEMENS S.p.A. 11 May, 1966 [29 Jan., 1966], No. 20879/66. Heading H4J. In a telephone handset (Fig. 2) comprising a mouthpiece 22 and a receiver 20 hinged together, the mouthpiece 22 includes a microphone, and a dial 38 is recessed in a cavity in the receiver 20. The handset may be closed, the mouthpiece 22 fitting into the dial cavity (Fig. 1, not shown). On opening the handset, two sets of switch contacts 46, 48 (Fig. 3a) are operated by a lever 50, 52, respectively, and a concave wedge 56 on each outer spring contact ensures that interruption of contact does not occur by minor relative oscillation of the two parts 20, 22. A helical spring 60 aids maintenance of the handset in the open position. Cable 76 between the two parts 20 and 22 runs from one side of part 20 to the other side of part 22 through an insulating tube 78 parallel to the axis of rotation 64. The receiver 20 comprises a base-plate 26 and a cover-plate 30. The mouthpiece 22 comprises a base-plate 28 and a cover-plate 32. The underside of the mouthpiece 22 has a U-shaped rubber pad (150), Fig. 13 (not shown), for ensuring sufficient grip of the base when placed on a horizontal surface and for absorbing shock when putting down the apparatus. A latch (156), Fig. 14 (not shown), provides stable closure and may be opened against spring action by pressing a bolt (160). A printed circuit board (88), Fig. 4 (not shown), has at opposite ends a choke (96) and a transformer (94) between which is fitted a circuit sub-assembly (86). The sub-assembly is fixed to the rear of the receiver 20 by two U-shaped brackets (100) one of which accepts the transformer (94) while the other accepts the choke (96). The receiver transducer and microphone are held by metal straps also described in Specification 1,151,785.</p> |
