Patent GB-471690-A (GB)
Abstract: 471,690. Moulding-machines. BRITISH INSULATED CABLES, Ltd., and HANNA, F. L. March 14, 1936, No. 7718. [Class 83 (i)] A moulding-machine, e.g. as described in Specification 321,777, [Class 83 (i)], is provided with an electromagnetic coupling 28, Fig. 3, between parts 1, 2 required at one time to move together and at another separately. The box 65, which stands on a double-sided pattern plate 64 resting in a frame 63 on a vertical pivot 62 is filled with sand and swung into position between a fixed head 3 and the box 2 also filled with sand. The coils 28, 16 are then energized, the latter causing the core 15 to lift the plate 1 and, through the coil 28, core 26, and collar 25, the box 2 until this engages the pattern plate 64 which it lifts from its frame 63 and presses the sand thereon against the plate 3. When the sand in the box 65 is fully compressed the plate 64 and box 2 are arrested but the plate 1 continues its upward movement, as allowed by the yielding nature of the coupling, until the sand thereon is also compressed. The coils are then deenergized and the parts 1, 2 fall to their original position, the box 85 being held by spring clips 66 and thus stripped from the plate 64 which, in turn, is arrested by the frame 63 and thus stripped from the bottom mould. The frame 63 and plate 64 are then swung aside and the coils again energized to assemble the mould, pressure between the halves being avoided by stops 82 on rods 31 engaging adjustable stops 83 on the machine frame 6. The assembled boxes are aligned by plates 70 and locked together automatically by gravity catches 72. The boxes are then lowered, the upper one being pulled from the clips 66, until the head 3 can be swung aside on its pivot 5, Fig. 1, the nut 10 of the abutment 8 first being released. The movements of the parts 1, 2 are regulated by pistons 33, Fig. 4, on the rods 31 operating in oil-filled cylinders 34, 'the bottoms of which are normally connected by a valve 58 to a tank 23 through an adjustable pre-set valve 47, and a piston 22 on an extension of the core 15 operating in an oil filled cylinder 21 the lower end of which is normally connected by a valve 57 to the tank through the pre-set valve 47. The upper ends of the cylinders 34, 21 are always connected to the tank through adjustable valves 42, 40. The valves 57, 58 are, at this stage, turned by a handle 49, Fig. 1, to connect the bottoms of the cylinders 34 to the tank 23 through a pipe 54 and prevent any escape of fluid from the bottom of the cylinder 21. Then the electric current is turned off so that the boxes 2, 65 descend, leaving the stripped mould on the plate 1. The mould is then removed and the handle 59 operated to allow the plate 1 to fall to its original position and the box 65 to be lifted from the box 2 and replaced on the pattern plate. The lower ends of the cylinders are supplied, when their pistons are rising, through a non-return valve 48. A stop device for limiting the downward movement of the table 1 and box 2 may comprise a pair of levers 85, Fig. 12, pivoted on the frame 18 at 86 and connected by a pin 89 and slot 90 so as to have two limiting positions. When the table 1 and box 2 fall together adjustable stops 91 of the former engage the outer ends of the levers and thus raise the inner ends to engage a collar 87 connected to the box 2, thus arresting both. When however the table 1 is held in raised position the outer ends of the levers do not encounter the stops 91 and the box can fall to a lower position for stripping the mould.