GB641858A - Improved process and apparatus for die-casting articles - Google Patents

Abstract

641,858. Moulding-machines. WOLVERHAMPTON DIE-CASTING CO., Ltd., WEST, V. J., and STOCKHAM, F. C. May 29, 1948, Nos. 14557, 16526 and 21949. [Class 87 (ii)] [Also in Group XXII] In a process for die-casting or moulding articles of metal or other material, the article is formed integrally with a surrounding web which is used to convey the article from the moulding position to at least one other position for a further operation. In one form, Figs. 2 and 3, the machine comprises a fixed plate 2 carrying a die part 1 and secured to a fixed cross-head 18 by rods 17 along which slides a plate 4 carrying another die part 3. Slidably mounted on pins 21 projecting forwardly from the plate 4 are two bars 5 formed with central longitudinal channels 7 and forming part of a carrier. Headed pins 23 pass through the plate 4 and are screwed into another plate 16 also slidable along the rods 17 and distance pins 24 screwed into the rear of the plate 4 extend rearwardly through the plate 16 and carry discs 25 to the rear of which are stop pins 26 adapted to abut the rear wall of a hollow slide block 19 and a stout central spindle 27 which passes through the block 19. Rotatably mounted in the cross-head 18 is a shaft 8 to which are fixed an operating lever, toggle links 30 at each side and in a recess in the crosshead a stepped stop member 32 which forms an abutment for the rear end of the spindle 27. The other links 31 of the toggles are pivoted to the block 19. Pivoted to opposite ends of the carrier are rearwardly extending catch levers 33 adapted to engage behind abutments 35 on the slide block 19 to secure together the block 19, plates 16 and 4 and the carrier. The catch may be released by studs 36 projecting from the toggle links 31. In operation, the operating lever is turned so as to move the carrier, plates 4 and 16 and block 19 up to the plate 2 and molten metal is injected into the mould space to form the article 13 secured in a thin plate with thicker edges 11 engaged with the grooves 7 of the carrier. The block 19, plates 4 and 16 and carrier are then withdrawn and separated, and the casting pushed along the carrier bars 5 by a piston, after which the parts are again brought together and another casting made. There is thus formed a continuous strip containing the cast articles and the projecting sprues from which the cast articles are punched on a succeeding movement of the plate 4, the co-operating punching dies being carried by the plates 2 and 4. In a modification, Figs. 8 and 10, an intermittently rotatable table 52 moves over a fixed table 51. At the casting station one of a series of dies 54 in the table 52 co-operates with a die 57 in the table 52 and with plungers 59, 60 to form a mould space into which metal is injected through a sprue 56, the casting comprising a blank 65, supported by a thin web 65x within a thicker supporting ring 66 to which is secured a runner 67. At other stations various operations are performed on the blank, such as severing part of it from the web and bending that part away from the plane of the blank, drilling and tapping the blank and finally punching the finished blank out of the web which is subsequently ejected and returned to the melting pot. If a plastic powder is to be used, the sprue 56 is omitted, powder is sprinkled into the die on the plunger 60 and the plunger 59 is then brought down to mould the powder.