Patent GB-793313-A (GB)
Title: Improvements in or relating to an automatic machine for the production of foundry moulds
IPC: B22C11/04
Filed: 1955-06-28
Abstract: 793,313. Moulding-machines. REGIE NATIONALE DES USINES RENAULT. June 28, 1955 [July 1, 1954], No. 18653/55. Class 83 (1). [Also in Groups XVIII and XXX] A foundry moulding- machine has a number of stations and a convoying element which brings successively into each of these stations a moulding-box resting on a support containing a pattern - plate, the machine including also box-filling means and a mechanism in the boxsupport which forms the impression in the mould and performs the mould-stripping operation by moving the fall box and the pattern with respect to a pressure element which accompanies the box during part of its working-cycle. The machine comprises a table 1 continuously rotated through gearing 2, 3 and carrying mould-box supports 5, and a pressureplate 6, which last is mounted on a column 8 and is locked to, and moves with, each support 5 in turn while the mould ramming and stripping operations are performed, the plate then rapidly returning to its initial position. The movement of the plate is effected by a Maltesecross device .29, Fig. 3, carried by the column 8, and a lever 27 carried on a shaft 26 carried by the table 1 and carrying a gear-wheel 25 which meshes with a fixed gear-wheel 24. In one revolution of the table, an empty box placed on a support 5, is automatically positioned thereon, filled, passed through a zone wherein a scraper distributes the sand and removes excess, the filled box is rammed, vibrated and stripped and the completed mould withdrawn by the operator. Each moulding-support comprises a ramming-piston 67, Fig. 5, in a body 65 and carrying a cover 75 which supports a pattern-plate. Mounted within the piston is a hollow-cylinder 78 which contains the mouldstripping piston 80, and comprises a chamber 82 which is partly filled with oil and communicates with the space 81 beneath the piston 80 through conduits 83, 84 and adjustable-valve 85, conduits 93, 99, 100 and orifices 94-97, and a one-way valve 101-103 communicating with an annular-chamber 98 into which the conduit 99 opens. The chamber 82 is supplied with -compressed-air through a non-return valve 105. In operation, when the mouldsupport reaches the position in which ramming is to take place, the pressure-plate 6 being in operative position, compressed-air is automatically fed to beneath the ramming piston 67, which is raised together with the mouldstripping piston 80 and frame 72 connected thereto, and the mould-box. The box engages the pressure-plate, and the frame 72 and piston 80 are thereby halted, the ramming- piston 67 and cylinder 78 continuing their upward-movement to force the pattern into the sand, until halted by stops 73 on the frame 72, the space 81 beneath the piston 80 having been reduced by the relative movement of the piston and the cylinder 78, and the conduits 93, 99 communicate only through. the orifice 94. In this position a pneumaticvibrator on the cover 75 is started by a cam, and the pattern-plate may also be electrically heated. At the position where mould-stripping is to commence, a fixed cam cuts off the supply of pressure air to beneath the piston 67, which, together with the elements it contains or supports, falls, the shock being cushioned by springs 70, 71. The piston 80 and frame 72 may then be moved upwardly to lift the mould from the pattern, the oil in the chamber 82 being displaced into the chamber 81 by the compressed-air delivered through the valve 105, the adjustment of the valve 85 determining the stripping-speed, and the progressive uncovering of the orifices 95-97 causing a slow starting speed and progressive increase. A spring 108 absorbs the shock when the piston abuts the cover 75. The box-filling device, Fig. 7, comprises a hopper 116, a bottomless container 121 movable on rails 117 and a carriage carrying a closure-plate 128. When a mould-box reaches its filling-position, pressureair is supplied to a jack 122, which pushes the container 121, filled from the hopper, to the left, carrying with it by means of a hook 124, the closure-plate 128 against the resistance of a jack 129. On arrival above a vibrating screen 132, the hook is released and the closureplate is returned by the jack 129 to its starting- position, allowing the sand to fall into the mould-box. As the table 1 continues its rotation, a cam actuates the supply of pressureair to the jack 122 to restore the container to its starting position. Cam-actuated contactors 134, 135 on the hopper framework control a vibratory-device facilitating downward movement of sand in the hopper.