Abstract: New ferrite pot core type products and fabrication methods are disclosed for production and assembly of tunable-inductance magnetically-soft ferrite devices. Unitary helical threads formed within the central opening of a ferrite pot core element provide controlled axial movement of a non-threaded male tuning member, carrying a ferrite rod, to adjust the air gap between spaced center posts of an assembled pair of pot core elements. Thread matching and registry requirements are eliminated by such unitary thread means which present either helical path die means, for cutting threads in a cylindrical nonmagnetic portion of a male tuning member or, circumferentially continuous helical threads, which deform nonmagnetic protrusions uniformly distributed about the periphery of a noncircular cross section nonmagnetic portion of a male tuning member during rotation of a male tuning member within a core element central opening.

Abstract: The present invention improves the processing and products of coprecipitation of Fe and other metals selected from Mn, Zn, Ni, and Mg as carbonates and hydroxides in the manufacture of magnetically soft ferrites. Teachings are provided which enable control of the characteristics, especially the particle shape of coprecipitated metal carbonates and hydroxides, to bring about significant advantages in further processing such as relief of critical sintering requirements to meet commercial specifications, improved intermediate products which can be more easily handled during processing, and improved quality magnetically-soft, compacted, ferrite components.In the manufacture of MnZn ferrites, sintering furnace temperatures encountered by components from the same batch can vary as much as 100.degree. C. while maintaining specifications of permeability and loss factor whereas, with prior ferrite materials, a variation of as little as 5.degree. C. to 10.degree. C.

Abstract: A bumper assembly for use in pin-ball games. The bumper assembly includes a plurality of bumpers that are connected by shafts to a kicker arm which is fixed to the core of the solenoid such that the plurality of bumpers are controlled together by the solenoid and only a single solenoid is required for all the bumpers. The playing surface and bumper are electrically conductive and are electrically connected to the solenoid. The ball played with the game is electrically conductive and will complete the electrical circuit between the bumper and playing surface to cause energization of the solenoid which will cause the bumper to move downwards and further cause the ball to be projected away from the bumper.

Abstract: A target assembly for use in games for personal entertainment and particularly pinball games, in which an electrically conductive ball traverses the base layer of a game board said base layer being electrically insulated from a contact plate. A multiscore plate is electrically connected to the contact plate and has a plurality of fingers that extend into a channell formed between the multiscore plate and a guide member such that, when the ball traverses the channel, it contacts the fingers of the multiscore assembly to complete an electrical current path between the contact plate and the base layer to trigger a scoring mechanism.

Abstract: Manufacturing process for ferrimagnetic materials and pressure compacted soft ferrite components utilizing a "wet" process for compositional preparation of materials in which metal carbonates and metal hydroxides are coprecipitated in controllably selected ratios.An aqueous solution of metal ions is formed by dissolving pure metals in acid. This aqueous metal ion solution is added to a predetermined solution of carbonate ions and hydroxide ions. Concentrations, temperature, and rates of addition are controlled to select the ratio of carbonate groups to hydroxide groups in the coprecipitated particles and the size of such particles.The controllably selected ratio of carbonate groups to hydroxide groups facilitates separation of the coprecipitation particles and maintains residual hydroxide groups in the material so as to extend solid-state reactivity of the coprecipitated particles for grain growth and densification purposes until the final heat treatment in which the pressure compacted articles are sintered.