Patent GB-1424560-A (GB)
Title: Rotational moulding apparatus
IPC: B29C41/40
Filed: 1973-12-28
Abstract: 1424560 Rotational moulding SEKISUI KAGAKU KOGYO KK 28 Dec 1973 [29 Dec 1972] 60093/73 Heading B5A Articles are rotationally cast in moulds 16 which are advanced along a first track 1, Fig. 1, through stations 2, 4 for removing finished articles and for refilling the moulds, and in the reverse direction along one of a number of second tracks 5 each parallel to the first track and provided with heating and cooling stations 7, 8. Pairs of moulds 16, Fig. 3, are mounted in carriages 9 for rotation with a shaft 15 driven by an electric motor 17 on the carriage. Another motor 19 drives the carriage along the tracks 1 and 5 and both motors pick up power from a wire 20 by means of brushes 201, Fig. 5. The carriages 9 are transferred between tracks 1 and 5 on further carriages 12 having rails 13 to receive the carriages 9 and running on tracks 10. Carriages with filled moulds are guided by a computer to a waiting station 6 on a track 5 and fed singly through doors 21 into a heating chamber 7. In chamber 7 heated air 75 is circulated by a blower 36 around the rotating moulds. Slots 71 in the chamber walls permit the wheels 18 and motors 17, 19 of the carriages to remain outside, heat loss being reduced by interdigitating baffles 76, 92. The carriages pass through further doors 21 into a cooling chamber 8 where water is sprayed on to the moulds. In a combined filling and unloading station, Fig. 6, one of the moulds 16 is moved to its lowest position and held by engagement of a pin 164 in its support arm 153. Cores 163 are engaged by electromagnetic chucks 25 which are displaced horizontally by hydraulic cylinders 252. A mould locking rod 261 and an unlocking rod 271 are attached to the chucks by means of cylinders 27, 26 which displace them alternately to operate a locking pin 164 on the mould. A platform 28 mounted on end of a carriage 29, 31 is raised by a cylinder 291 to engage a removable portion 166 of the mould and hold it by magnetic attraction. The mould is unlocked by movement of rod 271 and portion 166 is lowered on platform 30, the article 100 being retained by cores 163. The carriage is driven to the left along track 33 to bring the other end 31 under the mould. An article removing platform 30 is raised by cylinder 311 and suction pads 301 engage the article 100. The cores 163 are withdrawn by chucks 25 and the article is lowered on platform 30. The mould portion 166 is filled with thermoplastic resin and the carriage 29, 30 moved to the right for reassembly of the mould. Another rotational mould, Fig. 8, comprises plates 821 carrying cores 802 and pins 803 for engagement in holes 901 in a fixed mould portion 810. A removable portion 806 carries rods 808 which enter vertical holes 921 in blocks 812 on the fixed portion 810 and which have notches 809 for engagement by a locking bar 813 passing horizontally through the blocks 812. The locking bars 813 have notches which are aligned with the holes 921 to release the rods 808 therefrom to unlock the mould. The cores are retained by the rods 808 passing additionally through holes 805 in plates 804. Walls 819, 820 in the cores 802 form passages for heating fluid.