Patent GB-527360-A (GB)
Title: Improvements in or relating to die casting machines
IPC: B29D5/10
Filed: 1939-04-01
Abstract: 527,360. Casting-machines casting composite articles. FAIRWEATHER, W. C. (Morin, L. H.). April 1, 1939, No. 10244. [Class 83 (i)] [Also in Group V] A machine for casting articles, such as the fastener members of a sliding clasp fastener, on to a tape or other mounting member, comprises devices operated by compressed air for feeding the tape through co-operating dies and for injecting molten metal or thermoplastic material into said dies, controlled by valves 107, 121, Fig. 7, operated e.g. by cams 65, 66 and a catch 106 normally engaging the valve 107 to hold it in an inoperative position in which it prevents passage of air to said first device but admits it to the valve 121 by a port 123. This port is closed by the valve 107 when it is released by withdrawal of the catch 106 and thus allowed to be moved up by the spring 117. The dies 80 and their operating mechanism are carried by a casing 31 mounted in bearings 32, Fig. 2, in the frame 17, the casing having a plate 52 engaged by a spring-pressed roller 53a, Fig. 11, to hold the dies firmly against the injection nozzle 139 or, when the casing 31 has been moved by hand away from the nozzle for repairs &c. to hold it by engaging a recess 53b. The tape 83, Fig. 5, is passed from a reel 99 through spring pawls 104 mounted in a normally stationary bracket 101 and between the die parts 80. A core 84 of the die is moved down to feed the work, after each operation of the injection plunger 126 by air from the valve 121, by a bracket 95, sleeve 89, and spring 114 and is returned by a cam 69 and lever 92, after partial closure of the dies, to strip it. The dies are pivoted about the sleeve 89 and are opened and closed by grooved cams 67, 68 and arms 188. The cams 65 ... 69 are mounted on a shaft 60 which is rotated by a motor 20, Fig. 2, through a belt 27, clutch 35, shaft 26 and gearing 61, a brake 36 being provided to bring the cams to rest when the clutch is opened. The shaft 60 also carries a cam 70 engaging a normally fixed but adjustable roller 165, Fig. 7, so as to press the dies away from the nozzle 139 between each casting operation and a worm 71, Fig. 2, which drives a wheel 72, shaft 73, friction clutch 153, Fig. 7, wheel 152, and chain 74 this carrying spaced cams 74a, Fig. 10 to withdraw the catch 106 when it is desired to feed the tape without casting members thereon. The valve 107, when thus released, is actuated by spring 117 and cam 65 and admits air to a cylinder, Fig. 5, and lifts a piston 110, rod 76, and bracket 101 and when the air is exhausted these parts are moved down by a spring 111 and the pawls 104 feed the tape through the open dies. For a longer spacing a longer cam 74a holds the catch 106 withdrawn long enough to allow two such feeds. If the dies 80 are prevented from closing, the cams 67, 68 move towards each other, against the action of a spring 156a, Fig. 3 and, by means of a rod 156, lever 158, and rod 162, actuate a switch 163 to stop the motor 20. The dies are cooled by water circulated through pipes and passages 173, 172, 85, 87, 172a, and 173a, Fig. 5. The pot 128 is adjustably supported by a screw 140, Fig. 13, and a screw 138 engaging a link 135 pivoted to the frame 17 and to lugs 137a of the pot. This is heated by a thermostatically controlled burner 133. The injection chamber 127 is clamped with its nozzle 139 projecting through a hole 127a thereof, by a lever 148 engaging lugs on the chamber a pivot 149 of the pot and a screw 150. When removing the chamber 127 from the pot 128 this is tipped by lowering the screw 140 so that it need not be emptied. To prevent the metal from being withdrawn from the neck 146 when the plunger 126 rises this may be formed with an extension 126a, Fig. 17, which masks the port 127<SP>3</SP> before the port 144 is opened. In another modification, the extension has a spiral groove 126d, Fig. 19, so that by rotating the plunger the part of this groove which registers with the port 127<SP>3</SP> is varied longitudinally. The inlet port 144 registers with a circumferential groove 126e and both grooves are connected to the metal in the chamber 127, by longitudinal grooves. After adjustment the plunger is clamped to the actuating rod 245 by a collar 239 having a pin 242 engaging a groove 243 to prevent rotation and a scale 248.