Abstract: An indirectly heated cathode including a conductive cup having a closed end provided with an exterior surface coating of electron emissive material and an electrically insulated heater element disposed axially within the cup. The heater element comprises a coaxial pair of outer and inner filamentary coils wound helically in electrical series from a single strand of electrical wire and having integral interconnecting portions adjacent the closed end of the cup for resiliently supporting the inner coil within the outer coil and in alignment with the central portion of the electron emissive coating.

Abstract: An electron gun for a cathode ray type tube and comprising a coaxially aligned series of tubular electrodes insulatingly connected to one another to form a sub-assembly and an axially spaced glass stem having sealed through it an array of electrical terminal pins, at least one of the electrodes being electrically connected to a terminal pin through a hollow tubular conductor having crimped portions which permit misalignment of the stem with respect to the gun while supporting said sub-assembly of electrodes axially and anti-rotationally with respect to said terminal pins extending from the stem.

Abstract: An electron discharge device including an evacuated envelope having therein an indirectly heated cathode comprised of a metallic cathode cup having a cylindrical wall provided with an outwardly extended pair of opposing axially sloped flanges which contactingly engage respective opposing bevelled surfaces of a dielectric support ring encircling the wall and having an inner periphery radially spaced therefrom.

Abstract: A knob assembly comprising a cup-shaped knob shell having therein a coaxial pair of oppositely wound coil springs disposed for binding engagement with a surrounding wall of a race and having respective terminal end portions engaging an encircled portion of an axially rotatable bushing which is provided with fastening means for rotatably engaging an axially inserted shaft, the springs having other terminal end portions engaged by respective oppositely rotatable lever arms mounted on the bushing and having end portions aligned with axially spaced projections of the knob shell, whereby axial movement of the shell causes the projections to pivot the lever arms in opposite angular directions to release the coil springs windingly from binding engagement with the wall of the race and permit rotation of the bushing and engaged shaft in response to rotary movement of the knob shell.