Abstract: There is disclosed a switch-hookless telephone set having a housing in the configuration of a handset housing, a cord, a plug and, within the housing, circuitry comprising: a ringing network including a ringing oscillator, a voice network, a receiver, a magnetic transducer performing during voice mode operation of the set as an electroacoustic transducer, and a bistable snap-action OFF-ON switch having an actuating button exposed outside the housing. The switch is coupled to the network and transducer so as, when in a first or "ringing mode" position, to connect the ringing network to, and disconnect the voice network from, the leads in the cord while connecting and disconnecting the transducer to and from, respectively, the ringing oscillator and the voice network, and so as, when in a second or "voice mode" position, to effect the converse connections and disconnections. When the transducer is connected to the ringing oscillator, the transducer is responsive to tone signals therefrom to emit ringing sounds.

Abstract: The disclosure relates to a ring armature electroacoustic transducer adapted for use as the receiver for telephone sets and for other purposes. The exemplary embodiment comprises the following elements coaxial about a common vertical axis: (a) a cylindrical ring permanent magnet (15) of Fe-Cr-Co material, (b) an annular disc upper pole piece (20) seated on magnet 15 and having at its inner margin a downwardly salient annular boss (30) providing an upper pole tip, (c) a lower pole piece (35) providing an annular lower pole tip (37) and aflange (36) coupling such tip (37) to the bottom of the magnet, (d) an armature support (40) within the magnet (15), (e) an annular disc armature (50) seated on the support (40), (f) a diaphragm (60) on the armature (50), and (g) a terminal plate (45) supporting such elements. The armature (50) is seated on a circular edge (90) on the support (40). The support (40), lower pole piece (35) and plate (45) form a unitary structure.

Abstract: Disclosed are magnetically soft ferritic multiphase Fe-Ni alloys having a Ni content in the range of about 4 to about 16 weight percent, devices containing a body fabricated from such alloys, and method for heat treating such body. Appropriate heat treatment comprises a low-temperature anneal in the two-phase (.alpha.+.gamma.) region of the Fe-Ni phase diagram, and typically results in improved magnetic properties. In particular, alloys according to the invention having x weight percent of Ni have a maximum permeability .mu..sub.m at least as large as 1.5[25(16-x).sup.2 ]G/Oe. The alloys typically also have a coercive field H.sub.c at most as large as 0.7[0.65(1+0.6x)]Oe, a saturation induction B.sub.s of at least about 20 kG, a maximum incremental permeability .DELTA..mu., measured with an applied a.c. field of about 0.005 Oe, of at least about 150 G/Oe, and a yield strength to 0.2 percent offset of at least about 40 10.sup.3 psi, with all the material properties measured at room temperature.

Abstract: Electroacoustic devices are disclosed which comprise a permanent magnet and a magnetically permeable component. The permanent magnet is made of an Fe-Cr-Co alloy comprising 20-40 weight percent Cr and 3-30 weight percent Co; the permeable component is made of an Fe-Al alloy comprising 1.5-18 weight percent Al.In addition to a magnetic circuit, disclosed devices comprise means such as, e.g., an induction coil for inducing a variable magnetic field in the magnetic circuit. Also, devices comprise means for utilizing energy output in response to the magnetic field. Energy output may typically be in the form of an acoustical signal having desirably flat frequency response. Due to their low cost, disclosed devices are particularly suitable for use in telephone receivers and other mass produced articles.