Patent GB-493481-A (GB)
Title: Improvements in or relating to a method of manufacturing compound bodies of moldable material, and an apparatus for performing this method
IPC: B29C45/16
Filed: 1937-10-21
Abstract: 493,481. Injection - moulding. NEW BRUNSWICK DIE MOLDING CORPORATION, and NAST, L. Oct. 21, 1937, No. 28800. [Class 87 (ii)] In moulding compound bodies of thermoplastic material, an initial part 2, Fig. 20, is moulded and solidified by cooling and thereafter one or more supplemental parts 1 are moulded by injection onto and in contact with the initial part, thereby softening the initial part at least superficially to compound the two parts, and the compound body is solidified by cooling. The initial part may be injectionmoulded. Mould cavities 40, 41, for the part 1, and 51, 52, 51<1>, 52<1>, for the parts 2, are respectively provided in bodies 27, 45 mounted on a base 20. The body 27 is moved to and from the body 45 by toggle-links 23, 24 and lever 32. The body 45 is rotatably mounted on a body 60 fixed to the base. A pair of cavities 51, 52 is provided for each of the cavities 40. The body 45 is provided with through passages 55.. 58, 55<1> .. 58<1> whereof four passages, e.g. 55<1>, 57, 56<1>, 58, are adapted to register with passages in the body 60 in one rotational position of the body 45. The passages in the body 60 are connected to feed cylinders 70, fed from hoppers 78 provided with feed screws and adjustable gates. The material is forced along the cylinders 70 and into the mould cavities communicating therewith by plungers 94, 95 secured to a cross-head 96 operated by a piston rod 97 from a fluid-pressure cylinder 99. The fluid pressure is controlled by a slide gate. The cavities 40, 41 have lateral channels 42, 43 adapted to register with the feeding passages 57, 58 in one position of the body 45. The cavities 51 .. have lateral channels 53, 53<1>, 54, 54<1> communicating with the passages 55, 55<1>, 56, 56<1>. In the initial position of the body 45, two cavities 51, 52 register with the cavities 40, 41 and the cavities 51<1>, 52<1> are closed by flat surfaces of the body 27. The passages are so registered that a first material from two of the hoppers fills the combined cavities 40, 41, 51, 52 and a second material from the other hoppers fills the cavities 51<1>, 52<1>. The articles are removed from the cavities 40, 41, 51, 52 and the body 45 is rotated to register the cavities 51<1>, 52<1> and the initial parts moulded therein with the cavities 40, 41. The plungers are operated to force the first material into the cavities 40, 41 and unite as supplemental parts to the initial parts in the cavities 51<1>, 52<1>. Simultaneously the cavities 51, 52, row opposed by flat surfaces, are filled with the second material. The cycle is continued. The feed cylinders 70 may be heated as by electrical coils. Ejecting needles 122, 123 may be provided and remove articles from the cavities 40, 41 as the body 27 is moved back. Detachable moulds may be provided for the cavities 40, 41, 51, 52. For moulding cellulose acetate, there may be nickel moulds formed by casting nickel in a hollow metal body or by pressing powdered nickel therein. The hopper feed screws may be operated at varying speeds to regulate the material fed or by ratchet mechanism from the cross-head 96. The toggle-links 23, 24 rotatable body 45 and slide gate for the cylinder 99 may be operated by hand or mechanically from a common drive shaft, the body 45 being rotated by a peripheral gear. The bodies 27, 45 may be hollow for the circulation of cooling medium.