process for the manufacture of a ring of sintered oxydisch magnetized ferromagnetic material, in particular,,filled with a thermoplastic plastic or thermohardbare; matrix for carrying out this method; and ring, manufactured by application of the method.

摘要

1,094,114. Injection moulding. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. April 21, 1965 [April 24, 1964], No. 16779/65. Heading B5A. Stresses induced in a rotor 5 when a synthetic material is injected into the interior of the core are neutralized by injecting on the outside as well, the outer layer being subsequently removed. In one example (Fig. 1) liquid nylon or a liquid polycarbonate is injected through a duct 9 simultaneously with or just in advance of injection through a duct 8. The rotor is of sintered, oxidic, magnetic or ferromagnetic material and is for use in a small electric motor or generator. The rotor 5 is supported in the mould cavity by projections 3, 4. In a modification (Figs. 5, 6, not shown) both ducts 23, 25 are connected to a common supply opening 24, the duct for the outer side of the rotor being larger than the duct for the interior.