Patent GB-234437-A (GB)
Title: Improvements in acoustic apparatus
Filed: 1924-11-19
Abstract: 234,437. Weil, M. May 20, 1924, [Convention date]. Gramophones or the like combined with telephone receivers, for optional use as loudspeakers. - A combined phonograph and telephone or radio loud-speaker is provided with a stationary element mounted in or on the motor board and provided with passages connecting the tone-arm with the amplifying horn on the one hand and the telephone receiver with the horn on the other hand, a valve or valves being provided in connection with the stationary element adapted so as to place either the tone-arm or the telephone receiver in communication with the small end of the horn. The valve preferably also controls at will the size of the passage for either or both phonograph or radio use. According to the construction shown in Figs. 2, 3, and 6, a rectangular casting 15, mounted in an opening 14 in the motor board 11, is provided with a central control valve housing 21, to the lower end of which is secured the throat 19 of the amplifying horn. A valve 22, rotatably mounted in the housing 21, is operable by a knob 46, secured on the valve stem 40 and provided with a pointer working over a dial member 49, so as to place the horn in communication with either of a pair of passages 23, 24 in the casting at opposite sides of the valve. A telephone receiver 31 is secured in the inlet of the passage 23, which is of rams'-horn shape, by means of a bushing 30 secured by a set-screw 33 within a socket 32, a tone-arm 25 being swivelled in a socket member 26 at the open end of the passage 24. If it is desired to conceal the receiver 31, it may be mounted on a boss 34, Fig. 6, on the casting, the plug 35 which normally closes the boss being employed to close the inlet end of the passage 23. The valve 22 is provided with an opening 36, Fig. 3, adapted to register with the respective passages 23, 24 and is formed with a groove 37 which receives a set-screw 38 projecting through the valve casing and adapted to limit. movement of the valve in each direction. Move- - ment of the valve from the position shown to its midway position serves to control the volume of sound coming from the phonograph, the passage 23 being all the time completely closed. In the midway position of the valve both passages 23, 24 are completely closed, whilst movement of the 'valve beyond its midway position controls the volume of sound coming from the telephone receiver, the passage 24 being all the time completely closed. Fig. 7 shows a modification in which the casting 63 is secured over a circular aperture 62 in the motorboard 61, the neck 60 of the amplifier being secured immediately below aperture 62. In a further modification, Fig. 8, the tone-arm 83 is mounted over an opening 81 in the motorboard 80, below which is secured a globular valve casing 84 having openings 85, 86 registering respectively with the opening 81 and the neck 87 of the amplifier. The casing 84 is also formed with a lateral opening 88 registering with the enlarged end of the passage 89 in a casting 90 secured to the underside of the motorboard. The telephone receiver 91 may be secured at the smaller end of the passage 89 either inside the instrument as shown in full lines or above the instrument as shown in dotted lines. A rotary valve member 95, mounted within the casing 84 and operable by a knob 99, is provided with a through passage 96 for connecting the tone-arm with the amplifier and a radial passage 97, which co-operates with the passage 96 to establish communication between the telephone receiver and the amplifier when the valve is turned through a right-angle from the position shown. A construction embodying more than two passages to the amplifier throat may be employed.