GB637002A - Improvements in or relating to machines for making foundry cores and moulds - Google Patents

Abstract

637,002. Moulding - machines. HERBRUGGEN, H. SCHULTE-. March 11, 1948, No. 7432. [Class 83 (i)] A moulding-machine in which sand is fed from a container into a chamber from which it is blown into a core or mould-box supported on a table movable vertically by hydraulic or pneumatic pressure is characterized in that the sand container is intermittently rotated and has a shutter controlling the flow of sand into the blowing chamber and rotary control means for ensuring the proper sequence of operations. The table may be in two relatively movable parts, compressed air being supplied between them to intensify the pressure by which the core or mould-box is pressed on to the bottom of the blowing chamber. Mounted in the upper part of the machine frame is a sand container 12 divided into six compartments and rotatable by a motor 16 and chain 14 over a plate 17 having an opening 18 leading to a blowing chamber 19 of the kind described in Specification 570,193. The opening 18 is controlled by a shutter operated by a pneumatic cylinder 21. The core-box or flank is lifted into filling position on a table mounted on the upper end of a ram 25 operating within a cylinder 26 which at its lower end communicates by way of a passage 28 with a container 27 partially filled with oil and having means for admitting air under pressure above the surface of the oil. Communication between the container 27 and ram 26 is controlled by a valve 29 adapted to be pressed on to its seat to close the passage, by a spring 31 and to be opened by a plunger 32 subject to the action of a more powerful spring 38. The plunger is guided within a tubular member 33 depending from the closure plate 34 of the container, a cup-leather 35 secured to the head of the plunger working in an enlarged portion 36 which communicates with the interior of the container by way of small bores 39. When compressed air is admitted to the upper part of the container, oil is forced into the cylinder 26 and the table is raised until the corebox or flank engages the underside of the blowing chamber. The pressure within the oil container then rises until the plunger 32 is raised and the valve 29 closed to maintain the table in its raised position. The table comprises a lower part 24 secured to the ram 25, and to which is secured a flexible diaphragm 41, and an upper part 40 with a limited amount of vertical movement. After the table has been raised, compressed air is admitted to beneath the diaphragm 41 to increase the pressure of the core-box against the blowing chamber. Switches for operating the motor 16 and a motor 23 driving the blowing chamber agitator and valves controlling the supply of compressed air to the shutter-operating cylinder 21, to the blowing chamber, to the oil container and to the table, are all actuated by means of cams secured to a manually-operated shaft in a casing 45 so as to ensure a correct sequence of operations. Carriages at the same level as the table when in its lowered position, serve to carry the core-boxes or moulds to and from the machine.