Patent GB-728278-A (GB)
Title: Improvements in moulding machines for foundries
IPC: B22C11/04
Filed: 1953-07-21
Abstract: 728,278. Moulding-machines. BUDERUS'- SCHE EISENWERKE. July 21, 1953 [July 21, 1952], No. 20286/53. Class 83 (1). In a moulding apparatus comprising a rotary unit supporting a number of pattern plates, and means for automatically turning the unit intermittently to bring the pattern plates in succession to fixed moulding positions having mechanical devices for carrying out the separate moulding operations, the rotary unit is of light construction comprising essentially only a number of frame-like or arm-like supporting elements for the pattern plates, which elements may be mounted to pivot up. wardly towards the axis of the unit and the pattern plates preferably resting loosely on the supporting elements and being guided thereon by pins. The mechanical devices at the moulding positions are provided with individual fluid-pressure operated actuating units, and mechanism is provided for automatically controlling the operation of the apparatus with the desired sequence of operations, said control mechanism operating by the combined use of electrical or electromagnetic and pneumatic controlling and switching members. Pairs of arms 4, pivotable upwardly about shafts 5, support pattern plates 8 having pins 7 which seat in bearings 6. The arms are carried by a shaft 2 rotatable through gearing and a magnetic clutch by an electric motor 9. At a station A, Fig. 1, the empty moulding box 13 is set up on a pattern plate. At station B a table 15 mounted on springs 16 is moved upwardly by the piston of a cylinder 14 to lift the pattern and box off the arms 4 and support them against a spring-mounted sand hopper 18, a vibrator unit 20 being set into operation to consolidate the sand in the box. At station C a compressed-air press rams the sand in the mould, the upward stroke of the press piston lifting the pattern and box off the arms 4 before the box bears against the press head. Smaller pistons on the press head cause the pattern and box to follow the withdrawal of the press piston. Recesses in the press head, in which engage bars 25 of the moulding boxes, are cleaned of sand between working operations by compressed-air supplied through bores in tubes in the recesses. At station D a cylinder 29 first lifts the pattern and box from the arms 4 and then, preferably at a slower speed, pins 30 moving through openings in the pattern plate lift the moulding box from the plate. The table is locked by a pawl 33, Fig. 4, whose engagement with a cut-out 32 on a disc 31 carried by the shaft 2, actuates a switch 36a engaging the clutch 11 to the drive and causing, by relays 37 ... 39, the pistons of cylinders 14, 21, 29 at stations B, C, D to move upwardly. A limit switch 40 actuated at the upper limit of table 15 operates through a time relay 41 to switch on the driving motor for the sand distribution and, simultaneously or a few seconds later, the vibrator device 20. After a predetermined period these are switched off, the pistons lowered and limit switches 42 ... 44, actuated by the pistons in their lower position, cause the piston of a cylinder 36 to move the pawl out of engagement with the disc 31, the pawl in its outer position actuating a switch 46 to switch on the driving motor 9. The disc and column 2 rotate in the direction of the arrow, Fig. 4, and a cam 47 actuates first a limit switch 48, to switch off the motor 9, disengage clutch 11 and energize a magnetic brake 49, then a limit switch 50 to disconnect cylinder 36 from the fluid pressure supply and allow spring 35 to control the pawl to engage the next cutout 32, and finally a limit switch 51 to release the brake 49. For the setting down of the empty moulding boxes on the rotary unit and the removal of full boxes therefrom, compressed air units 52 as described in Specification 714,361, [Group XXX], suspended from rails and automatically controlled, may be used.