GB759254A

GB759254A - Improvements in or relating to casting

Info

Publication number: GB759254A
Application number: GB1044/52A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-01-12
Filing date: 1952-01-14
Publication date: 1956-10-17

Abstract

759,254. Casting-machines; moulds. BRENNAN, J. B. Jan. 14, 1952 [Jan. 12, 1951], No. 1044/52. Class 83 (1). [Also in Group V] In a pressure-casting machine a die, closed at its upper end to form at least one downwardly - directed cavity, is a sliding fit in a chamber containing molten metal so that on downward movement in the chamber, the metal is wholly received within the cavity. The lead-bronze or other metal is contained in a chamber 13 in body 10 of metal or ceramic having a passage 12 for a heating fluid. When the metal is at the correct temperature, e.g. just above its solidifying point, and after stirring to ensure uniformity, if necessary, a die 14 fitting the chamber 13 and having one or more cavities 17, corresponding to the castings required and open at the bottom, is moved down, thus forcing the molten metal into the cavities 17 without turbulence. The cavity 17 shown is formed by inserting, in a circular recess 16 and around a central plug 20, a helix 18, equal in depth to said recess 16, and a helix 19 of less depth. Rapid chilling may be ensured by nozzles 21, by flowing coolant through the passage 12 or by external fins &c. Vents 23, which may be used for evacuating, and pins 22 for ejecting and, if desired, applying pressure to the solidifying casting, before separating the parts 10, 14, may be provided. The parts 10, 14 may be pre-coated with lampblack, mica, graphite, &c., and preheated by high-frequency coils 30, 31. The strip 18 may be made from high-chromium nickel-ferrous alloy, cold rolled steel, asbestos or fibre-glass. The plug 20 may be made of carbon or other heat resistant material or be integral with the part 10. The cavities may be modified to cast, other forms, e.g. a series of rings, or may each consist of a separate die. Casting composite articles. If, in place of the strip 18, a double metal strip is used with the exposed'faces cleaned, tinned, &c., the cast metal becomes fused thereto to form a coated strip.