Abstract: A flat type commutator is provided which secures fixing of carbon (graphite) commutator pieces to both metal plates with terminals attached thereto for connecting winding and electrically insulating support, and which can be manufactured easily and at a low manufacturing cost. The flat type commutator has a brush slide-contact surface which is perpendicular to the axial direction of a rotor, wherein a plurality of commutator pieces (3), which are mutually isolated by slits (4), are directly fixed to an electrically insulating support (1), and a metal plate (5) for connecting the commutator pieces, each having terminals (6) for connecting windings is fixed on the outer peripheral surface of each commutator piece (3) which is parallel with the axial direction of the rotor.

Abstract: There is provided a flat type commutator which secures fixing of carbon (graphite) commutator pieces to both metal plate with terminals attached thereto for connecting winding and electrically insulating support, and which can be manufactured easily and at a low manufacturing cost.A flat type commutator with the brush slide-contact surface thereof being perpendicular to the axial direction of a rotor, wherein a plurality of commutator pieces 3 mutually isolated by slits 4 are directly fixed to an electrically insulating support 1, and a metal plate 5 for connecting said commutator pieces, each having terminals 6 for connecting windings is fixed on the outer peripheral surface of said each commutator piece 3 which is in parallel with the axial direction of the rotor.

Abstract: In a moving coil type dynamic loudspeaker of the type including a diaphragm vibrated by a moving coil disposed in an air gap of a magnetic circuit comprising permanent magnet, the diaphragm is supported by an annular suspension member. The inner portion of the suspension member is provided with a plurality of equally spaced openings along a circle concentric with the diaphragm and generally radially extending supporting pieces between the openings permit free axial movement of the diaphragm and the moving coil but prevent radial displacement thereof.