Patent GB-546155-A (GB)
Title: Machine for forming and trimming die castings
IPC: B22D31/00
Filed: 1941-04-05
Abstract: 546,155. Injection-moulding machines. PLASCO, Ltd. April 5, 1941, No. 4559. Convention date, July 25, 1940. [Class 87 (ii)] [Also in Group XXII] In a die-casting machine in which the material is injected into dies 23 containing a core 33, the core is withdrawn, when the dies separate, with the casting, which is then stripped and carried to a position in which it is trimmed. The dies 23, Fig. 6, being closed and the cores 32, 33 in position, the nozzle 43 of the injector 44, pivoted at 55, is pressed, through the action of a spring 56 and of adjustable link 57, lever 58, shaft 59, lever 60 Fig. 4, cam 62 and driven shaft 14, into firm contact with the dies, and casting material in the pot 46 is injected by a plunger 45 and air-operated piston 48. The dies are then separated by cam faces, not shown, on bars 24 moved by levers 26, and cam 25 and the core 33, with the casting 30, e.g. the slider of a separable fastener, thereon, is raised by an arm 35, Fig. 6, shaft 34, arm 38, Fig. 1, link 37 and cam 40. Meanwhile a carrier 42 on a shaft 68 has been moved, by teeth 69, 70, spring 76, links 64 and cam 63, into vertical position to receive a lug 31a, Fig. 6b, of the casting in its jaw 83 which has been opened by an air operated piston 85 and is then closed. Continued movement of the core 33 strips it from the casting which is then moved by the carrier 42 to the trimming position shown in full lines in Fig. 6. A punch 104, Fig. 5, operated positively by a link 131 and cams 135, 137, Fig. 1, on a shaft 138 driven from the main shaft 14, then punches the article from the gate &c. portion of the casting, and forces it though a fixed die 107 and against a spring-pressed die 109. Here a punch 110, operated by a piston 112, and punches 122, Fig. 6, operated by a lever 123 and piston rod 124 act on the casting. The tools 104, 110 and 122 are then withdrawn, the last extracting the casting until it is stripped by a plate 129 and drops into a receptacle, not shown. The carrier 42 is then moved to the position shown in broken lines in Fig. 6, the jaw 83 is opened by its piston and the scrap runner &c. is blown into a shoot 90 by an air blast from a nozzle 91, Fig. 1, and another air blast clears the trimming tools. The air for these purposes, and for operating the various pistons, and for spraying lubricant on the dies, cores, and trimming tools is supplied at the required times by a rotary valve 51 driven from the main shaft 14. The cam 40 and a cam 152, Fig. 1.arranged to open a valve 150 in the air pipe 50 which supplies the piston 48, are driven through a clutch 177 only when there is no excessive resistance to the downward movement of the core 33. Between the cam bars 24, Fig. 4, and their operating levers 26, springs 29 are arranged to avoid damage, if excessive resistance to closing the dies occurs, and mechanism 161 .. 166, connected to one bar, also operates a switch 167 to stop the machine. If the die 109, Fig. 5, is moved against the action of its spring 115, by the advance of the punch 104, this movement operates a switch 118 to stop the machine. Handles 130 and 169 are provided for moving the die 109 opening the dies 23 and a handle 18 with an extension 176 for operating the main clutch 17 from either side. Adjustable stops are provided to limit movements and align the carrier 42 with the dies 23 and then with the trimming tools, also a stop 174 which can be set in a raised position to prevent the carrier 42 from lowering a casting into position between the trimming dies so that it can be examined. An unbreakable window 172 pivoted at 170 is swung into position during casting. Specification 542,647 is referred to. The Specification as open to inspection under Sect. 91 comprises the use of the automatic trimming mechanism on die casting machines producing non-metallic or thermoplastic castings This subject-matter does not appear in the Specification as accepted.