| 摘要 |
984,414. Electro-acoustic transducers. INDUSTRIAL RESEARCH PRODUCTS Inc. Sept. 6, 1962 [Sept. 6, 1961], No. 10937/64. Divided out of 969,288. Heading H4J. A moving armature electroacoustic transducer comprises an elongated case having a motor mounted in one end and a diaphragm mounted at the other, the motor including an armature extending lengthwise of the case and being drivingly connected to the diaphragm. Fig. 1 shows a section through the embodiment of the invention comprising a casing 16 containing a sound chamber 72, one side of which is closed by a diaphragm 68 and which communicates with the outside of the case via an aperture 76 and tube 24 or by means of apertures 71 through the sound chamber 72 and the casing wall. Attached to the diaphragm is one end of an armature 48, the other end of which is fixed between flanges 34 and 36 of the case 16. The armature passes between the polepieces 52 and 54 of the bar magnets 56 and 58 and through the centre of coil 42, the flux path for the magnets being completed by the casing which is made of a flux conductive material. Fig. 5 is a view of the components of the transducer before assembly showing how the top, bottom and one end of the casing is made of one piece of material bent to a form into which the coil 42 locates between surfaces 38 and 40, and the sub-assembly of magnets 56 and 58, polepieces 52 and 54, and spacer member 6 and 62, locates between the surfaces 26 and 32 of the case, alongside the diaphragm assembly 70. The sides of the casing may be formed separately, e.g. as at 94 and 96 or they may comprise a unit with a shield 100 which encloses the flanges 34 and 36. The method of mounting the diaphragm 48 between the flanges of the casing 16 is said to allow adjustment of the position of the armature in the motor by bending the flanges relative to the rest of the case. The armature diaphragm assembly may be in one piece as shown in Fig. 8, the diaphragm being provided with Thuras tubes as disclosed in Specification 869,234. |
